Impact Assessment of Oil Spillage on Farmlands of ...

Journal of Environmental Science and Engineering Volume 5, Number 12, December 2011 (Serial Number 49)

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Journal of Environmental Science and Engineering Volume 5, Number 12, December 2011 (Serial Number 49)

Contents Aquatic Environment 1561 Groundwater Quality Assessment for an Indian Urban Habitat: A GIS Approach A. Saleem, M.N. Dandigi, K. Vijaykumar and P. Balakrishnan 1570 Kinetic Modelling of Liquid-Phase Adsorption of Sulfate onto Raw Date Palm Seeds S. Koumaiti, K. Riahi, F. Ounaies and B. Ben Thayer

Environmental Monitoring 1581 Impact Assessment of Oil Spillage on Farmlands of Some Communities in Ilaje Area of Ondo State, Nigeria O.C. Alaba and E.O. Ifelola 1585 Preliminary Assessment of Total Mercury in Bulk Precipitation around Olkaria Area, Kenya G.N. Wetang’ula 1596 Can Industrial By-products Be Used as Tools in Sustainable Agriculture? B. Tóth, L. Lévai and Sz. Veres 1604 Trace Metals in Sediments, Macroalgae and Benthic Species from the Western Part of Algerian Coast W. Benguedda, N. Dali youcef and R. Amara 1613 A Simple Bioassay Using Fluorescent Microbeads and Daphnia magna M. Kamaya, M. Sonamoto, K. Nagashima and E.N. Ginatullina

Environmental Ecology 1617 Sedimentary Environments, Geometry and Characteristics of the Sand Layers within the Basin of El Ma Labiod (Algero-Tunisian Borders) M. Hamimed, M. El Kadi and M. Al Shara 1624 Using Geospatial Information Systems in Analyzing Urbanization Impacts on Stream Habitats in Southern Mississippi Coastal Ecosystem E. Merem, S. Yerramilli, C. Richardson, J. Wesley, T. Walker, D. Foster, J. Williams, C. Romarno and E. Nwagboso

Environmental Management and Assessment 1642 Assessing the Production of Sugarcane-Derived Ethanol in Iran as a Transport Fuel from Economical and Environmental Point of View Sh. Bahadori 1648 A Survey on a Heat Exchangers Network to Decrease Energy Consumption by Using Pinch Technology B. Raei and A.H. Tarighaleslami 1654 Implementation of Cooling Systems to Enhance Dairy Cows’ Microenvironment M. Samer 1661 Ergonomic Aspects of Operation of IT Systems in Precision Agriculture T. Juliszewski and M. Walczykova 1668 Effect of Bentonite on the Sandy Soils of Arid Regions: Study of Behavior of an Association of Wheat and Chickpea H.Y. Reguieg, M. Belkhodja and A. Chibani 1678 Effect of Foliar Copper Fertilizer on Pineapple cv. N36 Planted on BRIS Soil at East Coast of Peninsular Malaysia A.M. Arshad, A.A. Marzuki and A. Aziz 1683 Evaluation of Environmental Impacts in the Wood Skidding with Tractors in Greece E. Karagiannis, P. Kararizos and M. Kalaitzi 1688 Evaluation of Social Environment Impact of Highway Construction Using Gray Matter-Element Information Entropy Model C.K. Hu 1695 Hydrological Modeling in a Semi-Arid Catchment Using SWAT Model M. Mosbahi, S. Benabdallah and M.R. Boussema 1702 Global Warming, Elites and Energy in Latin America: The Chilean Case C. Parker

Journal of Environmental Science and Engineering, 5 (2011) 1561-1569

D DAVID

PUBLISHING

Groundwater Quality Assessment for an Indian Urban Habitat: A GIS Approach A. Saleem1, M.N. Dandigi1, K. Vijaykumar2 and P. Balakrishnan3 1. Department of Civil Engineering, PDA College of Engineering, Gulbarga 585101, Karnataka, India 2. Department of Zoology, Gulbarga University, Gulbarga 585106, Karnataka, India 3. Department of Humanities, Geography & Urban Planning Program, Qatar University, Qatar Received: June 29, 2011 / Accepted: July 13, 2011 / Published: December 20, 2011. Abstract: Groundwater is an essential source of drinking water for many Indian urban habitats. Large numbers of people consume ground water instead of municipal tap water due to contamination of tap water. Groundwater is extracted from thousands of bore wells, and used for potable purpose without proper testing and treatment. This paper describes a groundwater quality monitoring strategy and database model developed for Gulbarga city, located in Karnataka, India. Sampling wells are selected one each in 55 wards of the city corporation having easy access for regular sampling. Various attributes of sampling wells including their spatial coordinates, location address and a photograph are registered for ready recognition on site. Water samples are collected and analyzed for various physico-chemical parameters. Spatial coordinates and levels of sampling points are measured on site using a hand held GPS instrument. Gulbarga city map is digitized. A GIS database of the measured spatial and water quality data is developed using ArcGIS Desktop 9.3, and ground water quality maps are prepared which may serve as useful tools for developing policy, and regulatory mechanism for sustainable groundwater use. Key words: Groundwater, water quality, GIS applications, urban water supply, drinking water.

1. Introduction Groundwater is of major importance in providing water supply, and is intensively exploited for private, domestic, and industrial use in many urban centers of the developing world. At the same time, the subsurface has come to serve as the receptor for much urban and industrial wastewater and for solid waste disposal. There are increasingly widespread indications of degradation in the quality and quantity of groundwater, serious or incipient, caused by excessive exploitation and/or inadequate pollution control. The scale and degree of degradation varies significantly with the susceptibility of local aquifers to exploitation related deterioration and their vulnerability to pollution [1]. Corresponding author: A. Saleem, masters in Environ. Eng., research scholar, main research fields: groundwater, water quality and water conservation. E-mail: [email protected].

Over 50% of the world’s population is estimated to be residing in urban areas, and almost 50% of the mega-cities having populations over 10 million are heavily dependent on ground water, and all are in the developing world. In India, there are over 20 million private wells, in addition to the government tube wells [2]. The large-scale need for food security and urban drinking water supply is dependent on groundwater. The dependency becomes acute particularly during summer, when demand of water for different purposes increases dramatically as compared to not so elastic supply position. This grim situation is likely to aggravate further with rapid growth in population, urbanization and industrialization. Consumption of water with high concentration of total dissolved salts and nitrate has been reported to cause disorders of alimentary canal, respiratory, nervous, coronary system, besides causing miscarriage and cancer [3]. Increasing dependency on groundwater and

1562

Groundwater Quality Assessment for an Indian Urban Habitat: A GIS Approach

widespread water pollution in urban India require regular monitoring of groundwater and developing suitable database. There are about 400 cities having population more than 100,000 and 800 cities with more than 50,000 populations in India [4] and this study provides an economical and scientific approach suitable for groundwater quality assessment for these types of Indian urban habitats. 1.1 Groundwater Pollution in Urban India Groundwater pollution is reported for many of the Indian cities, with an alarming rate of increase in some cases. Groundwater in different parts of Delhi, the capital city of India, is severely affected and has become considerably vulnerable to pollution with a wide range of contaminants, such as fluoride (< 1-16.0 mg/L) and nitrate (< 20-1600 mg/L). During the last decade, fluoride and nitrate levels in groundwater have increased by 2-6 times. In Punjab and Haryana, groundwater nitrate levels are reported to be in the range from < 25 to 1800 mg/L and fluoride level 1.5-45.8 mg/L [2]. Lucknow and Nagpur are the two major urban centers heavily dependent on ground water for private and industrial use. They are identified by a World Bank study to be under threat of urban pollution [1]. A recent study on groundwater in Bangalore City has shown many fold increase in contaminants in various locations. Apart from bacteriological contamination, the most prevalent contaminant noted was nitrate, which reached to over 700 mg/L in some parts of the city, showing manifold increase within 3 years. Some areas having below acceptable limit of nitrate of 45 mg/L showed an increased value of over 400 mg/L during 3 years. The nitrate contamination is reported to be largely from dumping of untreated sewage [5]. 1.2 GIS Applications in Groundwater Monitoring Many studies are conducted around the world on groundwater monitoring with GIS and remote sensing applications. Land use and groundwater quality data

were used to identify and locate common sources of groundwater contamination in the District of Columbia, USA. The multitude of data required for this study were compiled using GIS, to develop GIS maps for hydro geologic settings, land use categories, and specific urban pollution sources [6]. Nitrate contamination in Groundwater of the city of Konya, Turkey, was studied and mapped using GIS software package Arc View GIS 3.2. A hardcopy map of the city was digitized in the UTM projection system. The location of the wells, around 150 numbers, were obtained by a hand held GPS (Global Positioning System) receiver [7]. Rural Development Engineering Department, government of Karnataka, carried out an analysis of water sources quality in rural villages during 2000-2001 and developed GIS based maps showing spatial variation of specific water quality parameters [8]. GIS mapping of groundwater quality provides a synoptic view of the city/district/state and would form a powerful tool for monitoring water quality across a region. The GIS database also helps in decision-making process by identifying the most sensitive zones that need immediate attention. This process can also enhance foreseeing the quality fluctuations and decide upon the priority, schedule, corrective measures and protection aspects with finer details. 1.3 Frequency of Groundwater Sampling Groundwater sampling and monitoring for large production wells that pump from over 300 feet depth, sampling every year to once in few years is sufficient because changes in water quality for such a well will be gradual. Shallower wells particularly domestic wells with smaller pumping rates should be sampled once or twice a year because they are more prone to short-term variations in groundwater quality and contamination [9]. Once in 6 month sampling for ground water is recommended when supplied for drinking purpose [10]. Central Groundwater Board (CGWB) of India arranges water quality testing for


about 15000 observation wells spread all over the country once a year during the month April/May, when the possibility of dilution caused by rainfall is the least [11]. Detailed monitoring is carried out at CGWB, where the temporal as well as spatial density of the samples are increased as per the need. In general, the analyzed parameters include EC, pH, Cl, CO3, HCO3, SO4, NO3, Na, K, Ca, Mg, Si, F. National Water Policy-2002 also stipulates both surface water and ground water to be regularly monitored for quality. The frequency of sampling and testing needs to be increased in urban areas having potential pollution problems. The test parameters and location and number of sampling in such zones need to be carefully selected and the database developed to monitor groundwater quality on regular basis. Where untreated groundwater is being used for drinking purpose, as in the study area, frequent samples shall be collected to monitor water quality. The sampling shall preferably cover monthly and seasonal fluctuations, and extend over a period of one year, thereafter random, seasonal checks may be performed. 1.4 Groundwater Quality Studies of Gulbarga City Groundwater quality of Gulbarga city has not been investigated with spatial reference. One study [12] reports groundwater quality of 72 bore wells of the City, maintained by Karnataka Urban Water Supply and Drainage Board, based on random sample collected during October to December 1990. Chemistry of groundwater sampled from 25 bore wells in the city and 5 in the adjacent villages, with special reference to its suitability for drinking purpose, was studied showing monthly variation in water quality for a period of two year 1999-2001 [13]. Another study [14] covers water quality analysis for 55 bore wells, sampled during the month August/September 2004. Parameters analyzed in the above references were temperature, pH, DO, EC, alkalinity, CO3, HCO3, hardness, Ca, Mg, Na, K, Fe, Cl, SO4, PO4, NO3, F, Fe, BOD, COD, and MPN. It is

1563

noted that there is no record for identification of sampling station, common extent and continuity of sampling. Area of monitoring, season, period and parameters of test also are different due to which the data from above studies is not useful to compare water quality changes over extended time/zones within the city. The Department of Mines and Geology of the state of Karnataka performs annual water quality analysis during April/May for one monitoring well, located in Aiwan-e Shahi area of the city. This department analyses only few physico-chemical parameters and the analysis results are also not made public, and are available only on payment. Thus the groundwater monitoring taken up by the state government does not meet the rational criteria for urban and potable use of groundwater, as they have one sampling station, in a city where the number of bore wells exceeds 20000, and the location of the sampling point is also not representative of the city environment, since it lies in an isolated and protected zone. Establishment of suitable number of sampling points, with geo referenced coordinates, detailed location address, various attributes of wells including various water quality parameters and sampling frequency, and developing a water quality data system incorporating Remote Sensing and GIS techniques, is needed to link groundwater quality studies undertaken by various governmental and other agencies. This will help optimize resources in effectively monitoring groundwater quality for sustainable use in urban habitats.

2. Study Area Gulbarga is a fast developing city in northern Karnataka. It is the divisional headquarter and one of the important education centers of the state. The City is situated at Latitude of 17o15′ to 17o25′ and Longitude of 76°45′ to 76o55′ (Fig. 1), at the mean sea level of 454 m and referred into sheet No. 56 C/SE. The City is spread over an area of 65 km2, and

1564

Fig. 1


India map showing location of Gulbarga city and sampling well locations.

has a population of 530,000 and 50,000 properties [15, 16]. Average annual rainfall observed over the period 1964-1994 is about 750 mm and the mean daily temperatures for the same period ranges from 19 oC in winter (November-December) to over 40 oC in summer (March-June). The rainfall distribution is 70% during south-western monsoon period (June to September) and about 20% in north-eastern monsoon period (October-December) and the rest in the pre-monsoon period. The study area is identified as chronically drought prone district of the Karnataka state, due to less and variable occurrence of annual rainfall which puts onus on exploitation and management of the sub surface water [17]. The City is served by piped potable water supply derived from Bennithora and Bhima rivers and Bhosga reservoir located 10-25 km away from the treatment plant. Water supply is augmented through more than 1600 bore wells installed and maintained by City Corporation, out of which about 1000 bore wells are fitted with hand pumps, and about 300 each operated through single phase motors and power pumps. There is no record of the number of private bore wells in the city. Based on physical observation it may be safely quoted that almost every third house has one bore well and the total number of bore wells

in the city may exceed 20,000, which means more than 300 bore wells per sq km area. Dependency on groundwater is currently very high and it is preferred for drinking purpose by large number of the population. Because of the inadequacy and poor quality of tap water, ground water will continue to be a significant source of domestic water supply for this region.

3. Materials and Methods Samples are collected from 55 bore wells, representing one from each zone/ward of the city, in the morning between 6-10 AM and immediately transferred to the laboratory. Water is discharged from the sample well for 2-3 minutes and container washed with the same water two to three times before collecting the water in 2 L plastic cans. Samples are analyzed for various physico-chemical parameters such as pH, DO, EC, alkalinity, CO3, HCO3, hardness, Ca, Mg, Na, K, Fe, Cl, SO4, PO4, NO3, F, Fe, BOD, COD [18]. Only TDS and NO3 values assessed for the month of March 2009 are included in this paper for illustration of mapping. Spatial coordinates and levels of sampling points are measured on site using a hand held GPS instrument GARMIN GPS-60. The handheld GPS instruments are time and cost effective when

1565


compared to traditional surveying equipments and techniques. Various attributes of the sampling wells collected on site include well type, location, pump type, year of installation, water use, depth of well, maintenance condition of public wells and photos of

Fig. 2 Table 1

wells. Depth of groundwater below ground level is measured on site by inserting a rope through the casing of the well (Fig. 2). Table 1 shows primary data based on field measurements and lab analysis of the study area conducted during March/summer 2009.

Latitude, longitude, ground level and groundwater depth measurement. Primary data of sampling wells and groundwater quality.

Type/ Ward ID of /zone # well

Latitude

1

HP

17° 21.600′ 76° 51.179′ 471

2

HP7

17° 21.294′ 76° 51.685′ 477

3

HP

17° 21.299′ 76° 52.232′ 478

10.5

4

HP13

17° 21.140′ 76° 50.996′ 474

3

5

HP-4

17° 20.829′ 76° 51.110′ 465

14.7

6

HP5

17° 20.937′ 76° 49.901′ 473

7

HP6

17° 21.424′ 76° 50.278′ 485

8

HP6

17° 21.492′ 76° 50.426′ 488

8.7

Shivaji Nagar, near Raja house and Laxmi kirana store

800

49

9

HP6

17° 20.042′ 76° 50.724′ 478

6

Bank Colony, near house of Mahindernat mulge and opp house of Nandgokul 840

75

10

HP7

17° 20.850′ 76° 50.901′ 471

24

1260

110

11

HP1

17° 20.928′ 76° 51.271′ 470

9.3

Khaja Clony, near Bibiraza college, baitul hafiz

930

89

12

HP3

17° 20.729′ 76° 51.425′ 481

3.9

Ramji Nagar, near Habib clinic and devout electricals

900

35

13

PW

17° 20.369′ 76° 51.533′ 465

30

Yadulla Colony, near Baqers function hall and KPTCL office

14

HP8

17° 20.774′ 76° 51.006′ 459

10.2

RozaB, near Alia guest house and new art ladies tailor

15

EP

17° 20.783′ 76° 50.747′ 463

22.5

16

HP3

17° 20.909′ 76° 50.447′ 475

8.1

17

HP

17° 20.736′ 76° 50.201′ 480

9

Ayarwadi, near Bavani temple

1040

89

18

PW

17° 21.245′ 76° 49.349′ 476

2.4

Aland Colony, near genius school & Akash medicals

920

40

19

HP2

17° 20.638′ 76° 49.513′ 469

3.6

Kailash Nagar-behind fort, near Shivaling temple and house Girijanivas

1470

44

20

EP

17° 19.897′ 76° 48.964′ 471

7.2

Madina Colony, opposite house E-11-3651 and near house E-11-3671

1320

128

21

HP2

17° 20.377′ 76° 49.128′ 479

7.8

New Raghvendra Colony, opp saraswathi house/ Hanuman temple

650

35

22

HP9

17° 20.463′ 76° 49.488′ 478

4.5

Ganga Nagar, near Chowdeshwar high school

930

57

23

HP4

17° 20.983′ 76° 49.742′ 475

4.8

Shahbazar, near Hanuman temple opp chowdeshwar book stall

590

35

Longitude

Ground level (m)

Depth of water Borewell address (mbgl) Kapnoor, opposite Kapnoor industrial estate association office near burial 7.5 ground 11.1 Bulandparvaz Colony, near Dr Rafeeq clinic and Muslim resident School

TDS NO3 (mg/L) (mg/L) 830

62

1570

124

Gandhi Nagar, near Malgatti road transformer

660

97

Bilalabad, near pirakatta and transformer

870

66

Chotaroza, near roza police station, and govt kerosene oil shop

1440

80

3

Filterbed, near Sharda STD and Shiva kirana shop

1170

35

7.8

Channaveer Nagar, near water tank opposite govt quarters

1300

133

Nayamohalla, near old gumbad,mosque and behind womens hostel

870

40

1190

102

Siddiambarbagh, near Datta temple and opp. House E-7-1665

1120

102

ImbliMohalla, opp BSNL tel exchange,Nehruganj

1050

44

1566


(Table 1 continued) Type/ Ward ID of /zone # well 24 HP7

Latitude

Longitude

Ground level (m)

17° 20.659′ 76° 50.294′ 478

Depth of water Borewell address (mbgl) 5.7 Rangeen Majid, opp house E-6-1339, near factory E-8-5039

TDS NO3 (mg/L) (mg/L) 1450

62

25

HP8

17° 20.821′ 76° 50.486′ 470

9

Mominpura, near Ekkhana mosque and house E-7-546

1100

155

26

HP12

17° 20.663′ 76° 50.576′ 470

9

Kharibowli, opposite house E-7-546

1090

155

27

PW

17° 20.284′ 76° 50.750′ 459

21

Sangtrashwadi, house of Er Hakeem, No. 4-551/1

1630

186

28

HP4

17° 20.325′ 76° 51.417′ 460

12

Basveshwar Colony, near shiva temple

1630

150

29

HP10

17° 20.144′ 76° 51.414′ 455

11.1

Adarsh Colony, near Hanuman temple and LIG 36 house

960

111

30

HP1

17° 20.137′ 76° 50.821′ 451

12

Gubbi Colony, near govt tool room and training centre

1410

49

31

HP4

17° 20.314′ 76° 50.545′ 471

11.1

Makhtampur, opposite gadduge math & Basveshwar higher primary school 1480

150

32

HP3

17° 20.190′ 76° 50.289′ 489

17.1

Gajipur, opposite chakkrikatta temple and kirana store

860

33

EP

17° 20.275′ 76° 49.732′ 458

5.7

Sharan Nagar, opp SB temple and sindgi Bhavani temple and transformer

970

22

34

HP1

17° 20.022′ 76° 49.658′ 460

4.8

Kumbargalli, near Ram temple and Goa hotel

1170

146

35

HP2

17° 20.228′ 76° 49.388′ 467

4.5

Brhampur, opposite Bhavani temple and near house E-10-3142313

520

18

36

HP2

17° 19.857′ 76° 49.109′ 471

4.8

Ashok Nagar, near house E-11-3594 and opposite Nandu kirana store

37

HP4

17° 19.995′ 76° 48.988′ 477

7.8

Jeelanabad, near the house No. E-11-4099 and electric motor

38

PW

17° 20.042′ 76° 48.556′ 466

1.5

39

HP9

17° 19.692′ 76° 49.114′ 463

27.3

40

HP1

17° 20.051′ 76° 49.433′ 465

4.8

Basvanagar, near the Kiran store and Basva clinic

41

HP4

17° 19.592′ 76° 49.422′ 474

6

SB College, near the college and Mallikarjuna STD

740

40

42

HP9

17° 19.924′ 76° 49.525′ 459

7.5

Mahant Nagar, near jabhavani kirana store & scrap shop

1510

133

43

HP1

17° 19.821′ 76° 50.204′ 457

11.1

Jagath, Tirandaz theater cross and near Annapurna hospital

1510

230

44

HP14

17° 20.154′ 76° 50.367′ 466

15.9

Attarcompound, near Karnataka primary school opp house Vimalkunj

810

57

45

HP11

17° 19.783′ 76° 50.559′ 459

9.6

Sundar Nagar, opposite MR medical college and near govt. hospital

780

40

46

HP10

17° 19.549′ 76° 51.472′ 456

16.2

Jayanagar, near shringar beauty parlour & Pallavi refereshments

990

43

47

HPN

17° 19.296′ 76° 50.928′ 443

10.2

Rajapur, behind petrol pump and near house E-24-55

710

53

48

HP7

17° 18.992′ 76° 50.221′ 457

11.1

Aiwaneshahi, near MSI college & govt independent college

840

49

49

EP

17° 19.552′ 76° 49.912′ 453

9.9

Khuba plot, in the compound/basement of Eshwar temple

50

HP3

17° 19.467′ 76° 48.964′ 467

6

CBI Colony, opp Sangita ladies tailor and near Bodishree nilaya

51

HP1

17° 19.070′ 76° 49.403′ 460

52

HP12

53

HP3

54 55

Husain garden, right third cross, fourth house on left

66

820

71

1700

221

920

97

Shanti Nagar, near srishanti finance and opposite Mahadev house E-11-5940 650

49

1280

150

820

53

1190

111

19.8

Venkatesh Colony, opp Rajlakshmi kidney hospital, near shrusheet medicals 1040

155

17° 19.112′ 76° 49.585′ 452

18

Station area, near Mohan bar and opp Dr Rahmatulla clinic

750

40

17° 18.824′ 76° 49.836′ 460

10.2

89

HP

17° 18.751′ 76° 49.256′ 457

14.1

HP

17° 17.916′ 76° 49.590′ 443

7.5

Naganhalli, near house E-1-4347 and Anil nivas, water tank 1050 Kotnoor housing board, opp house Devikrupa,plot 2, Christ covent PU 1180 college GDA Layout, near laboratory, private college teachers GUG office 780

252 35

HP-municipal bore well fitted with hand pump; EP-municipal bore well fitted with electric motor; PW-private bore well fitted with electric motor. mbgl: meters below ground level.

across the city area and the depth of water as

4. Results and Discussion

measured during summer 2009 are prepared. A map

A hard copy of the city development plan is

showing population density across different wards of

digitized and geo referenced. Latitude and longitude

the city is also prepared to reflect the extent of

recorded for sampling wells as shown in Table 1 are

population effected by groundwater contamination.

converted to UTM coordinates (Zone # 43N), using

Photos of sampling wells are also added in GIS

Geographic Calculator [19]. Water quality attributes

database.

for each sampling wells are transferred in ArcGIS

Total dissolved solids (TDS) varies from 520 mg/L to 1700 mg/L. Desirable limit for TDS in drinking water as per Indian standards (BIS-10500 1991) is 500

desktop

version

9.3.1,

and

maps

showing

concentration of TDS and nitrates in groundwater


mg/L, while WHO recommends a limit of 1000 mg/L. It is observed that TDS in water from all bore wells is above the desirable limit prescribed in the Indian standard. Central part of the city, which accounts for high density population (Fig. 3), has higher TDS water and so are the north east and south west block (Fig. 4). Nitrates in drinking water shall be within 45 mg/L [20] and 50 mg/L [21]. Gulbarga city groundwater samples shows NO3 varies from 18 mg/L to 252 mg/L. Only 15 out of 55 sampling wells have NO3 within permissible limit of 45 mg/L. Many samples have nitrates by alarming excess values (Fig. 5). The highest nitrate value of 252 mg/L is found in samples from ward No. 54, Kotnoor housing board, which may be attributed to agricultural runoff and open drains/nallas receiving sewage flow from sizeable area of the city. Similarly higher nitrates (230 mg/L) is noticed in groundwater samples near downstream end of Jagath tank and KBN tank (186 mg/L) and (146 mg/L) by adjacent to water logged trench around Gulbarga fort in ward No. 34. Nitrates in groundwater exceeds the permissible limit of 45 mg/L in thickly populated wards such as Roza, Khaja colony, Mehboobnagar, Naya Mohella, Mominpura, Kharibowli, Sangtrashwadi, Maktampur, Jagath and Jeelanabad and ranges from 75 to 221 mg/L. There are two pockets of high nitrate in the city central area having values between 100 and 200 mg/L. There is also a sizable area in the south west having high nitrate groundwater. Most of the city groundwater falls within 45-100 mg/L nitrate contaminants (Fig. 5). Leaking sewers, open drains, septic tanks and ill planned solid waste dumping coupled with unsanitary conditions around the borewells may contribute to excess NO3. TDS and NO3 combined are critical in the pockets in city centre and southwest. As groundwater in the city is heavily polluted it shall not be used for drinking without proper treatment. Depth of groundwater is more in summer and as per field measurements made in summer 2009, the depth

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Fig. 3 Population density in persons/km2.

Fig. 4

Total dissolved solids in mg/L.

is found to vary from 1.5 to 30 m (Fig. 6). More depth is noted in the southern and old part of the city which may be attributed to higher extraction of groundwater apart from the geological formation. Relative shallow depth of water and poor drainage system is polluting groundwater as seen through higher nitrate content across the city.

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Fig. 5


Nitrates in groundwater in mg/L.

Groundwater depth

governmental agencies is not satisfactory at urban centres and moreover there is no spatial database for such work. It is essential to monitor groundwater quality extensively in urban areas on a regular and scientific basis. Suitable GIS database for groundwater quality shall be developed and shared for effective management of this precious resource. An attempt has been made in this paper to describe groundwater quality of Urban Gulbarga with a GIS perspective and geo-referenced groundwater database and maps are developed which are useful for formulating sustainable groundwater use policies and public health projects. Primary data is collected for representative sampling wells and water quality is analyzed for summer 2009. It is noted that quality of groundwater in Gulbarga exceeds Indian standards for drinking water on the basis of measured values of TDS and nitrate. Regular monthly/seasonal sampling of groundwater and analysis for physico-chemical and bacteriological test is recommended for safeguarding public health and effective groundwater management.

Acknowledgments The authors sincerely thank authorities of PDA College of Engineering, Gulbarga, and Gulbarga University Gulbarga (Zoology Dept.) for their facilities and support provided for this study. Information provided by Gulbarga Urban Development Authority, City Corporation, and Department of Mines and Geology is also gratefully acknowledged. Fig. 6

Depth of groundwater in mbgl.

5. Conclusions In many Indian urban habitats there is significant contamination of groundwater, mainly from leaking sewers, open drains, septic tank, storm water runoff and haphazard dumping of municipal solid waste. Untreated groundwater is used for drinking in many of the cities. Groundwater quality monitoring by various

References [1]

[2] [3]

[4]

S. Foster, Adrian lawrence and brian morris, groundwater in urban development: Assessing management needs and formulating policy strategies, WTP 390, World Bank Technical Paper No. 390, 1998. P.S. Datta, Groundwater ethics for its sustainability, Current Science 89 (2005) 812-817. P.M. Reddy, S. Rao, Effect of industrial effluents on the groundwater regime in Vishakhapatnam, Pollution Research 20 (2001) 383-386. D. Pranati, Urbanisation in India, in: Population Process

Groundwater Quality Assessment for an Indian Urban Habitat: A GIS Approach in Urban Areas European Population Conference, June 21-24, 2006, available online at: http://epc2006.princeton.edu/download.aspx?submissionI d=60134. [5] The Hindu daily, Bangalore City’s Ground Water Unsafe, Divya Gandhi, 2007, available online at: http://www.thehindu.com/2007/02/15/stories/200702152 2940300.htm. [6] J. Schneider, J.V.O. Connor, C. Wade, F.M. Chang, H.M. Watt, Urban land use activities and the groundwater: A background survey of the district of Columbia, WRRC Report No. 141, Washington D.C., 1992, pp. 123-128. [7] B. Nas, A. Berkaty, Ground water contamination by nitrates in the city of Konya Turkey: A GIS perspective, J. Environmental Management 79 (2006) 30-37. [8] H.K. Ramaraju, Groundwater quality assessment in rural districts of Karnataka-A GIS approach, Journal of Indian Water Works Association 36 (2006) 887-884. [9] T. Harter, Groundwater sampling and monitoring, publication 8085, Division of Agriculture and Natural Resources, University of California, 2003, available online at: http://anrcatalog.ucdavis.edu/FarmWaterQualityPlanning/ 8085.aspx. [10] T.S. Rao, Analysis of Water and Industrial Effluents, Visakhapatnam, India, 1984. [11] Central Ground Water Board, Ministry of Water Resources Government of India, 2009, available online at: http:

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//www.cgwb.gov.in/GroundWater/GW_Monitoring.htm. [12] A.M. Maniyar, Evaluation of groundwater quality of the bore wells of Gulbarga City, maintained by KUWS&D board, Dissertation, PDA College of Engineering, Gulbarga, 1990. [13] M. Shashikanth, K.V. Kumar, M. Rajashekhar, Chemistry of groundwater in Gulbarga district, Karnataka, India, Environ. Monit. Assess. 136 (2008) 347-354. [14] N.S. Patil, Groundwater quality analysis of Gulbarga city using GIS technique, Dissertation, PDA College of Engineering, Gulbarga, 2004. [15] Gulbarga City Corporation, 2009, available online at: http://www.gulbargacity.gov.in. [16] Census of India, 2001, available online at: http://www.censusindia.gov.in. [17] R.R. Ahamed, Hydrogeological studies of Gobbur Basin gulbarga district, Karnataka. Ph.D. Thesis, Gulbarga University, Gulbarga, 1998. [18] APHA, AWWA and WEF, Standard Methods for the Examination of Water and Wastewater, 20th ed., New York, 1998. [19] Franson, CoordTrans v2.30 Build18, Franson Technology AB, Sweden, 2003, available online at: http://franson.com/coordtrans. [20] BIS 10500 (Bureau of Indian Standards), Indian Standard Drinking Water Specification, 1st ed., 1991, pp. 1-8. [21] WHO (World Health Organization), Guidelines for Drinking-Water Quality: Recommendations, 2nd ed., 1993, pp. 174-180.


D DAVID

PUBLISHING

Kinetic Modelling of Liquid-Phase Adsorption of Sulfate onto Raw Date Palm Seeds S. Koumaiti, K. Riahi, F. Ounaies and B. Ben Thayer Laboratory of Chemistry and Water Quality, Department of Management and Environment, Higher School of Engineering in Rural Equipment Medjez El Bab, Beja 9070, Tunisia Received: December 29, 2010 / Accepted: July 13, 2011 / Published: December 20, 2011. Abstract: Adsorption kinetics in multi-component systems has been a subject of intensive research because it is of both theoretical and practical importance. In this paper, raw date palm seeds (RDPS) were investigated to assess the possible use of this raw material as an effective adsorbent for the removal of sulfate from aqueous solution. The influence of various parameters such as sulfate initial concentration, pH, adsorbent dose and stirring time has been studied for the adsorption of sulfate in batch mode. Effects of foreign anions on the adsorption of sulfate onto RDPS have been also investigated. The pseudo-second-order, Elovich and intraparticle diffusion kinetic models have been developed to predict the rate constants of adsorption and equilibrium capacities. The maximum adsorption capacity of sulfate (qe ≈ 3.2 mg/g) onto RDPS was reached for the initial sulfate concentration = 100 mg/L, pH = 3.5, adsorbent dose = 10 g/L and for a stirring intensity = 200 rpm at 25 ± 2 °C. The results showed that the adsorption of sulfate onto this raw materials followed pseudo-second-order rate kinetic predicting a chemisorption process. Key words: Adsorption, sulfates, batch mode, raw date palm seeds, kinetics models.

1. Introduction Sulfate is the most abundant form of sulfur found in soils under aerobic conditions and the main ionic species of this element that is absorbed by plants [1]. Consequently, we found a high concentration sulfate in wastewater. At the same, the consumption of drinking water containing sulfate concentration in excess of 600 mg/L commonly results in laxative effects [2]. The taste threshold for the most prevalent sulfate salts ranges from 250 to 500 mg/L [1]. While the world health organization does not propose a health-based guideline for sulfate in drinking water, it does recommend that health authorities are notified if sulfate concentration exceeds 500 mg/L [3]. Therefore, at high concentration, sulfate causes catharsis, dehydration and gastrointestinal irritation [4]. Removal of this ion from ground water is of significant importance from an environmental point of view. Efficient removal of Corresponding author: S. Koumaiti, Ph.D., research fields: water quality and treatment. E-mail: [email protected].

sulfate from water is a complex problem due to the high solubility and stability of these anions in aqueous solutions [5]. There are several methods for treating wastewater containing sulfate anions. The removal of this anion by ion exchange [6], reverse osmosis, electro dialysis, neutralization with CaCO3 [7], biological treatment [8, 9] and chemical precipitation were studied. Studies on the adsorption of sulfate by δ-Al2O3 [10], chitin based shrimp shells [11] and goethite [12] have been reported in literature. Most of these methods suffer from drawbacks like high capital and operational cost and problems in disposal of the residual metal sludge. Activated carbons are the most popular adsorbents used for the removal of toxic substances from water. This could be related to their extended surface area, high adsorption capacity, microporous structure and special surface reactivity [13]. However, due to their high cost, their use is not feasible. So there is a need for cheaper and readily available materials for the removal

Kinetic Modelling of Liquid-Phase Adsorption of Sulfate onto Raw Date Palm Seeds

of toxic pollutants from water [5]. Date palm is a principal fruit that is grown in many regions of the world, resulting in a surplus production of dates. Date palm seeds constitute approximately 10% of the fruit [14]. The adsorption process provides an attractive alternative treatment, especially if the adsorbent is inexpensive and readily available. Raw and activated date palm seeds are widely used as an adsorbent for the removal of phenols [15], dyes [16], heavy metals [17, 18], aluminum [19] and pesticide [20]. In this paper, adsorption kinetics experiments with sulfate were conducted and different kinetic models, such pseudo-second-order equation, intraparticle diffusion and Elovich model, were used to analyze adsorption processes of sulfate onto raw date palm seeds water interface, to describe the rate and mechanism of adsorption, to determine the factors controlling the rate of adsorption, and to find out the possibility of using this material as a low-cost adsorbent for the removal of sulfate in aqueous solution. The effects of initial sulfate concentration, solution pH, adsorbent dose, intensity of stirring and competitive anions on the efficiency of sulfate adsorption onto raw date palm seeds were also studied.

2. Materials and Methods 2.1 Preparation and Characterization of the Adsorbent The raw date palm seeds (RDPS) used in this research are from date palm obtained from Kebili (southern of Tunisia). The raw materials, date palm seeds, were thoroughly washed with distilled water to remove all dirt and then oven dried over night at 105 °C. The dried pits were then crushed, milled and sieved into different particle sizes. Studies were focused on a size fraction of 0.8 < Ø < 1 mm. The pH of the aqueous slurry was determined by adding 1 g of RDPS in 50 mL distilled water, stirred and the final pH was measured after 24 h. The determination of pHZPC of RDPS was performed according to the solid addition method [21]: 50 mL of 0.01 M KNO3 solution was placed in conical flasks.

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The initial pH of the solutions was adjusted to a value between 2 and 9 by adding 0.1 M HCl or NaOH solutions. Then, 1 g of RDPS was added to each flask, strirred and the final pH of the solutions was measured after 24 h. The value of pHZPC can be determined from the curve that cuts the pHi line of the plot ΔpH versus pHi. 2.2 Adsorption Kinetic Study Sulfate adsorption kinetics study was carried out with different initial concentration of sulfate and kept the concentration of the adsorbents at room temperature (25 ± 2 °C). Before the start of each kinetic experiment, 1000 mg of sample was loaded in 1 L. Six levels of initial sulfate concentration (20, 40, 50, 60, 80, 100 mg SO42- /L) were used. The pH of the solution was maintained at a defined value by manually adding H2SO4 and/or NaOH solutions (0.1 M). The flask was capped and stirred magnetically at 200 rpm for 300 min to ensure approximate equilibrium. Solutions of CO32-, HCO3-, Cl- and C2O42- were prepared from their sodium salts. Effect of these anions on the removal of sulfate (50 mg/L) was studied. Several milliliters of reaction solution was sampled for intervals between 0 and 300 min of adsorption. At the end of adsorption period, the solution was filtered through a 0.45 µm membrane filter and analyzed for SO42-. Measurements were made in triplicates for the analysis of SO42- parameter and data were recorded when the variations in two readings were less than 5%. In this paper, all data represents an average of three independent experiments (N = 3) and data represent the mean value. 2.3 Sulfates Analysis The sulfate species stock solution containing 1000 mg SO42- /L was prepared by dissolving sodium sulfate (Na2SO4) powders (analytical reagent grade) in bidistilled water. Sulfate working solutions in different concentrations were prepared by diluting the SO42stock solution with distilled water. The pH of solution was adjusted using minimum volume of H2SO4 and/or

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NaOH (0.1 M). The total volume added for pH adjustment never exceeded 1% of the total volume. The analysis of sulfate was done spectrophotometrically at 450 nm, following the Sulfa Ver 4 method [22]: dilute solutions react with Baryum Chlorure and Citric Acid to obtain a white turbidity in the presence of sulfate. 2.4 Sulfate Uptake The quantity of adsorbed sulfate onto raw date palm seeds was calculated from the decrease of the sulfate concentration in solution. The SO42- uptake was calculated following the concentration difference method. The equilibrium adsorption capacity was calculated using the equation below: C − Ce (1) ×V qe = i M Where, qe (mg/g) is the equilibrium adsorption capacity, Ci and Ce are the initial and equilibrium concentration (mg/L) of SO42- anions in solution, V (L) is the volume and M (g) is the weight of the adsorbent. 2.5 Kinetic Models 2.5.1 Pseudo-Second-Order Kinetic Model The pseudo-second-order kinetic model assumes that adsorption is a pseudo-chemical reaction process and the adsorption rate can be determined. Based on equilibrium adsorption, the pseudo-second-order kinetic equation [23, 24] is expressed as:

1 1 t = + t 2 qt qe k II q e

(2)

Where, kII is the equilibrium rate constant of second-order adsorption (g/mg/min). 2.5.2 Elovich Kinetic Model Elovich equation is also used successfully to describe second order kinetic assuming that the actual

qt =

1

β

ln (αβ ) +

1

β

ln (t )

(3)

Where, α is the initial adsorption rate (mg/g·min), and the parameter β is related to the extent of surface coverage and activation energy for chemisorption (g/mg). 2.5.3 Intra-Particulate Diffusion Kinetic Model The pseudo-second-order and Elovich kinetic models could not identify the diffusion mechanism and the kinetic results were then analyzed by using the intra-particle diffusion model. In the model developed [27-29], the initial rate of intra-particle diffusion is calculated by linearization of Eq. (4):

qt = k d t 1 2 + C

(4) Where, C (mg/g) is the intercept and kd is the intra-particle diffusion rate constant (mg/g·min1/2). Also, the diffusion coefficients for the intra-particle transport of sulfate within the pores of raw date palm seeds particles have been calculated by employing Eqs. (5) and (6) [30]. 0 . 03 r 2 t1 / 2 1 = Kq e

Di =

(5)

t1 / 2

(6)

Where, Di is the diffusion coefficient with the unit cm2/s; t1/2 is the time (s) for half-adsorption of sulfate and r is the average radius of the adsorbent particle in cm. All constants were calculated from the intercept and slope of the line obtained from linearized form of models. The equations corresponding to each model and their linearized forms, plots, slopes and intercepts are presented in Table 1.

3. Results and Discussion

solid surfaces are energetically heterogeneous, but the

3.1 Effect of Initial Concentration and Time

equation does not propose any definite mechanism for

The amount of sulfate anions adsorbed for different initial concentrations onto RDPS is shown in Fig. 1. The results have shown that adsorption process is clearly time dependent. The amount of sulfate adsorbed, q (mg/g), increased with the increase in sulfate

adsorbate-adsorbent. It has extensively been accepted that the chemisorption process can be described by this semi-empirical equation. The linear form of this equation [25, 26] is given by:

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Table 1

Linearized form, plots, slopes and intercepts of the used kinetic models.

Kinetic model

Linearized form

Plots

Pseudo-second order model

t 1 1 = + t 2 qt qe k II q e

t vs t qt

Elovich model

qt =

Intraparticle diffusion model

qt = k d t 1 2 + C

1

β

ln (αβ ) +

1

β

ln (t )

qt vs ln(t )

qt vs t 1 2

Slopes 1 qe

Intercepts 1 k II q e

1

1

β

β

kd

C

2

ln (αβ

)

Fig. 1 Effect of initial sulfate concentration and time: adsorbent dose = 10 g/L; pH = 3.5; stirring intensity = 200 rpm; temperature = 25 ± 2 °C.

concentration and remained nearly constant after equilibrium time. It was shown that the adsorption at different initial concentration was rapid in the initial stages and gradually decreased with the progress of adsorption until the equilibrium reached 120 min. At low concentrations the ratio of available surface to the initial sulfate concentration is larger, so the removal becomes independent of initial concentrations. However, in the case of higher concentrations this ratio is low; the percentage removal then depends upon the initial concentration. The curves are continuous leading to saturation, suggesting the monolayer coverage of sulfate on the surface of the adsorbent [31]. After a balance time of 2 h, the adsorption capacity records an increase from 1.2 to 3.2 mg/g, respectively for concentrations from 20 to 100 mg/L. This may be due to the fact that at a chosen adsorbent dose, the number of active adsorption sites to accommodate the adsorbate ion remains unchanged

while with higher adsorbate concentrations, the adsorbate ions to be accommodate increase. At the higher initial concentrations, we have the higher corresponding cumulative removal (mg/g). 3.2 Effect of pH The pH of aqueous solution is an important controlling parameter in the adsorption process. The pH of the system determines the adsorption capacity due to its influence on the surface properties of the RDPS and different ionic forms of the sulfate solutions. Change of the adsorption capacity of sulfate onto RDPS with pH is shown in Fig. 2. It was observed that the maximum adsorption capacity (2.6 mg/g) occurred at pH 2.5. Maximum adsorption at acidic pH indicates that the low pH leads to an increase in H+ ions on the carbon surface which results in significantly strong electrostatic attraction between positively charged RDPS surface and sulfate ions. The capacity of sulfate

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Amount Adsorbed (mg/g)

3 2.5 2 1.5 1 0.5 0 2.5

3.03

3.51

3.94

4.9

6

8

9

10

pH

Fig. 2 Effect of pH on the adsorption of sulfate onto RDPS: adsorbent dose = 10 g/L; contact time = 120 min; stirring intensity = 200 rpm; sulfate concentration = 50 mg/L; temperature = 25 ± 2 °C.

adsorption gradually decreased to 0.33 mg/g at pH 10. Adsorption of sulfate onto RDPS was not significant at pH values greater than 6.0 due to anions competition to be adsorbed on the surface of the adsorbent of which OH- predominates. The pHZPC of an adsorbent is a very important characteristic that determines the pH at which the adsorbent surface has net electrical neutrality. At this value, the acidic or basic functional groups no longer contribute to the pH of the solution. Anions adsorption will be more favourable at pH value under pHZPC. The value of pHZPC of RDPS is close to the value of pH of

Fig. 3 The determination of pHZPC of RDPS.

aqueous slurry which is 5.21 (Fig. 3). 3.3 Effect of Adsorbent Dosage The sorbent concentration is another factor that influences the sorption equilibrium. In order to examine the effect of the sorbent dosage on the removal efficiency sulfate, adsorption experiments were set up with various amounts of RDPS (2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 g/L) at initial sulfate concentration of 50 mg/L and with pH = 3.5. The effect of sorbent dosages on the amount of adsorbed sulfate has been shown in Fig. 4. It was shown that the quantity


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2.4

Amount adsobed (mg/g)

2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 2

4

6

8

10

12

14

16

Adsorbed dose (g/L)

Fig. 4 Effect of adsorbent dosage on sulfate removal: contact time = 120 min; stirring intensity = 200 rpm; sulfate concentration = 50 mg/L; pH = 3.5; temperature = 25 ± 2 °C.

of sulfate adsorbed increased in a significant way in the pondered range examined. In addition, we observe that the maximum of retention is obtained for a mass of 10 g of RDPS per liter of solution. For this quantity, capacity of adsorption records its highest value (2.24 mg/g). For the other adsorbent doses, the capacity of adsorption increased by 1.51 to 1.97 mg/g for the respective adsorbent doses from 2 to 8 g/L. Beyond an adsorbent dose of 10 g/L, the capacity of adsorption decrease to 1.62 mg/g. This is probably because of the resistance to mass transfer of sulfate from bulk liquid to the surface of the adsorbent, which becomes important at high adsorbent loading in the conical flask in which the experiment was conducted. It might have happened that the higher dose causes particles aggregates and interference or repulsive forces between binding sites, therefore decreases the interaction of sulfate ions with the sorbent and reduces the total surface area of the adsorbent. 3.4 Effect of Stirring Intensity Experiments were conducted to investigate the effect of stirring intensity on the sulfate adsorption onto RDPS for initial sulfate concentration of 50 mg/L, with pH = 3.5, amount of adsorbent = 10 g/L, at 25 °C and at intensity of stirring rates of 50, 100, 150, 200, 250 and 300 rpm. As can be seen from Fig. 5, with increased stirring intensity the adsorption capacity of sulfate

increased to 2.25 mg/g for a stirring intensity of 200 rpm and remained almost stable for 250 and 300 rpm. It indicates that at higher stirrer rpm (> 200) the external mass transfer becomes negligible [32]. Subsequent experiments were conducted with 200 rpm stirring intensity. 3.5 Effect of Foreign Anions Systemic examination and quantitative information on the relative competition for adsorption onto natural waste and especially under products of the raw date palm seeds among these anions with different binding affinities are rather scarce. Sulfate at a concentration of 50 mg/L and adsorbent dose of 10 g/L were used to examine the effect of foreign anions. Adsorption of sulfate decreased by the addition of foreign anions: CO32- , HCO3- , Cl- and C2O42- (Fig. 6). With regard to the anions speciation, the sulfate adsorption capacity decreased in the following order: CO32- = HCO3- > C2O42- > Cl-. In this case, other study reported that there are other anions which have an effect in the decrease of sulfate removal such as MoO42-, ClO4-, NO3- and PO43- [5]. 3.6 Adsorption Kinetic Modelling The studies of adsorption equilibrium are important in determining the effectiveness of adsorption. However, it is also necessary to identify the types of

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Amount adsorbed (Mg/g)

Fig. 5 The variation of the adsorption capacity of sulfate at various stirring intensity: adsorbent dose = 10 g/L; contact time = 120 min; sulfate concentration = 50 mg/L; pH = 3.5; temperature = 25 ± 2 °C.

Fig. 6 Different concentrations of foreign ions effects on the removal of sulfate: sulfate concentration = 50 mg/L; contact time = 120 min; stirring intensity = 200 rpm; pH = 3.5; temperature = 25 ± 2 °C.

adsorption mechanism in a given system. In order to test the applicability of the three different kinetic models, namely the pseudo second-order, the intraparticle diffusion model and the Elovich kinetic model, the experimental data were correlated with the linear forms of the three models, respectively. The derived rate constants together with the correlation coefficient r2 for the different initial concentration of sulfate have been listed in Tables 2-4. Figs. 7-9 display the best-fitting results, also shown in the figures are the experimental data. Several conclusions can be drawn from Tables 2-4 and Figs. 7-9. The application of the linear form of pseudo-second-order kinetic model on our

experimental results is presented in Fig. 7. It can be seen from Table 2 that the kinetics of sulfate adsorption onto raw date palm seeds follow this model with correlation coefficients higher than 0.99 and the equilibrium adsorption capacity, qe, increases as the initial sulfate concentration, Ci, increased from 20 to 100 mg/L. For example, the values of qe increased from 1.24 mg/g for 20 mg/L to 3.19 mg/g for 100 mg/L. Further, it was found that the variations of the rate constant, KII, seem to have a decreasing trend with increasing initial sulfate concentration. These results imply that chemisorption mechanism may play an important role for the adsorption of sulfate onto raw date palm seeds.


Table 3 lists the kinetic constants obtained from the Elovich equation. It will be seen that the value of α and β varied as a function of the initial sulfate concentration. Thus, on increasing the initial sulfate concentration from 20 to 100 mg/L, the value of α decreased from 3.47 to 1.40 mg/g·min due to the less available surface for sulfate. On the other hand, an increase in the initial sulfate concentration from 20 to 100 mg/L leads to an increase in the value of β from 0.168 to 0.504 g/mg. For

the Elovich model, the correlation coefficients (r2) are relatively low lying between 0.91 and 0.96. It indicates that the Elovich model was not the most suitable for describing the adsorption kinetic of sulfate onto raw date palm seeds. The correlation coefficients (r2) for the intraparticle diffusion model are between 0.930 and 0.991 (Table 4). It was observed that intra-particle rate constant values (Kd) increased with initial sulfate concentration. The

Table 2 Parameters for pseudo-second-order kinetic model. Ci (mg/L) 20 40 50 60 80 100

qe (exp) (mg/g) 1.245 1.631 2.249 2.554 2.935 3.193

KII (g/mg·min) 0.019 0.018 0.016 0.013 0.012 0.007

qe (cal) (mg/g) 1.623 1.939 2.959 3.047 3.279 3.849

r2 0.9939 0.9939 0.9906 0.9914 0.9936 0.9928

β (g/mg) 0.168 0.230 0.238 0.375 0.422 0.504

α (mg/g·min) 3.478 2.901 2.131 1.796 1.675 1.400

r2 0.9486 0.9688 0.9198 0.9578 0.9687 0.9555

Table 3 Parameters for Elovich equation. Ci (mg/L) 20 40 50 60 80 100

qe (exp) (mg/g) 1.245 1.631 2.249 2.554 2.935 3.193

Table 4 Parameters for intra-particle diffusion model. Ci (mg/L) 20 40 50 60 80 100

qe (exp) (mg/g) 1.245 1.631 2.249 2.554 2.935 3.193 Ci = 20mg/L

Kd (mg/(gmin^0.5)) 0.133 0.159 0.226 0.255 0.273 0.329 Ci = 40mg/L

Ci = 50mg/L

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Di (cm2/s) 0.12×10-6 0.17×10-6 0.32×10-6 0.44×10-6 0.51×10-6 0.73×10-6 Ci = 60mg/L

Ci = 80mg/L

t1/2 (min) 5.21 3.55 1.90 1.38 1.19 0.82 Ci = 100mg/L

Fig. 7 Second-order-sorption kinetics of sulfate onto RDPS at various initial concentrations.

r2 0.9475 0.9593 0.9917 0.9307 0.9437 0.9396

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Ci = 20mg/L

Ci = 40mg/L

Ci = 50mg/L

Ci = 60mg/L

Ci = 80mg/L

Ci = 100mg/L

Fig. 8 Elovich plots for sulfate adsorption onto RDPS at various initial concentrations. Ci = 20mg/L

Ci = 40mg/L

Ci = 50mg/L

Ci = 60mg/L

Ci = 80mg/L

Ci = 100mg/L

Fig. 9 Plot of intra-particle diffusion modelling of sulfate onto RDPS at various initial concentrations.

observed increase in Kd values with increasing initial sulfate concentration can be explained by the growing effect of driving force resulted in reducing the diffusion of sulfate species in the boundary layer and enhancing the diffusion in the solid. The corresponding values of intraparticle diffusion rate constant, Kd, for the various concentrations of the sulfate (20-100 mg/L) varied from 0.133 to 0.329 mg/g·min1/2. From Fig. 9, it can be observed that the straight lines did not pass through the origin and this further indicates that the intra-particle diffusion is not the only rate-controlling step. The diffusion coefficients Di varied from 0.12 × 10-6 to 0.73 × 10-6 cm2/s with an increase of initial sulfate concentration from 20 to 100 mg/L. At higher sulfate concentration the attraction between the functional groups of raw materials and sulfate species gets

stronger. The values of the internal diffusion coefficient, Di, fell well within the magnitudes reported in literature, specifically for chemisorption system (10-5 to 10-13 cm2/s) [30]. 3.7 Comparison of RDPS with Others Adsorbents The application of low-cost and easily available materials in wastewater treatment has been widely investigated during recent years. Particularly, the sulfate adsorption on different materials has been widely studied during recent years. It can be found that the sulfate adsorption onto date palm seeds tends to decrease with the increase of pH, from 2.65 mg SO42-/g at pH 2.5 to 0.33 mg SO42-/g at pH 10. As can be seen from Table 5, the pH value of the sulfate solution plays an important role in the whole adsorption process


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Table 5 Adsorption capacity q of various adsorbents reported in literature. Adsorbent Coir pith carbon ZnCl2 activated coir pith carbon γ-Al2O3 Chitin-based shrimp schells Soil Granite sand Raw date palm seeds

pH 4.0 4.0 5.7 4.5 6.2 6.2 3.5

and particularly on the adsorption capacity. Similar trends were also observed for sulfate adsorption on others adsorbents. To illustrate the potential in the use of raw date palm seeds in actual applications, a comparative evaluation of the adsorptions capacities of various types of low-cost adsorbents for the sorption of sulfates species is provided in Table 5. This comparison clearly indicated that raw date palm seeds are an effective adsorbent for sulfate removal. Chitin-based shrimp schells [11] appeared to have higher sulfate adsorption capacity approximately 156 mg/g than other materials, which may be attributed to the chemisorption, a more significant contributory phenomenon to the removal of SO42- than physical adsorption. However, γ-Al2O3 [10], coir pith carbon [5], ZnCl2 activated coir pith carbon [5], soil [33] and granite sand [34] seemed to have a minor sulfate adsorption capacity than other materials. In comparison with some mineral and organic materials the sulfate species seem to be efficiently removed from aqueous solutions using date palm seeds as raw and natural adsorbent.

4. Conclusion 2-

Removal of SO4 from aqueous solution onto raw date palm seeds was carried out at room temperature. Results indicate that pH, initial sulfate concentration, stirring intensity, adsorbent dosage and foreign anions impacted sulfate specie removal: the SO42- uptake increased with the increase of initial sulfate concentration and decreased with increasing pH values. It is also seen that a further increase in adsorbent dose (greater than 10 g/L) affects the uptake of sulfate

q (mg/g) 0.06 4.9 7.7 156 2.06 1.2 3.19

Reference [5] [5] [10] [11] [33] [34] Present study

adsorption greatly. The conditions of maximum adsorption of the sulfate anions were optimized. In nature and in normal treatments, the treated waters are usually at pH from 2.5 to 10, so the adsorption capacity of SO42- is about 2.25 mg/g at pH 3.5, for an adsorbent dosage of 10 g/L, initial sulfate concentration of 50 mg/L, under a constant temperature of 25 ± 2 °C, and the equilibrium state was reached within 120 min of exposure time. The results showed that the adsorption of sulfate onto raw date palm seeds followed pseudo-second-order rate kinetic predicting a chemisorption process. The results of present investigation show that the relatively low cost and high capabilities of the raw date palm seeds make them potentially attractive adsorbents for the removal of sulfate from aqueous solution. Further experiments need to be conducted to test the dynamic sorption of SO42- onto raw date palm seeds in fixed bed column.

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[2] [3] [4] [5]

[6]

M.E. Alves, A. Lavorenti, Sulfate Adsorption and Its Relationships with Properties of Representative Soils of the Sao Paulo State, Brazil, Geoderma, 2003, p. 89. World Health Organization, Guideline for Drinking Water Quality, 2nd ed., Geneva, 1996. American Water Association, Water Quality and Treatment, 5th ed., Mc Graw Hill Inc., New York, 1999. World Health Organization, Guideline for Drinking Water Quality, 2nd ed., Vol. 1, Geneva, 1993, pp. 122-130. C. Namasivayam, D. Sangeetha, Application of coconut coir pith for the removal of sulfate and other anions from water, Desalination 219 (2009) 2. J.J. Schoem, A. Steyn, Investigation into alternative water treatment technologies for the treatment of underground mine water discharged by Grootvlei Proprietary Ltd. into

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[9]

[10]

[11]

[12]

[13]

[14]

[15]

[16]

[17]

[18]

[19]

Kinetic Modelling of Liquid-Phase Adsorption of Sulfate onto Raw Date Palm Seeds the Blesboksprint in South Africa, Desalination 133 (2001) 13-30. J.P. Maree, H.A. Greben, M. De beer, Treatment of acid and sulfate-rich effluents in an integrated biological/chemical process, Water SA 30 (2004)183. L.A. Du Preez, J.P. Odendaal, J.P. Maree, M. Ponsomby, Biological removal of sulfate from industrial effluents, using producer gas as energy source, Environment and Technology 13 (1992) 875-882. J.P. Maree, G. Hulse, D. Dads, C.E. Schutte, Pilot plant studies in biological sulfate removal from industrial effluent, Water Science and Technology 23 (1991) 1293-1300. C.H. Wu, C.Y. Kuo, C.F. Lin, S.L. Lo, Modeling competitive adsorption of molybdate, sulfate, selenate, and selenite using a Freundlich-type multi-component isotherm, Chemosphere 47 (2002) 283-292. A. Moret, J. Rubio, Sulfate and molybdate ions uptake by chitin-based shrimp shells, Minerals Engineering 16 (2003) 715-722. R.P.J.J. Rietra, T. Hiemstra, W.H. Riemsdijk, Sulfate adsorption on goethite, Journal of Colloid Interface Science 218 (1999) 511-521. D. Nevskaia, A. Saantianes, V. Munoz, A. Guerrero-Ruiz, Interaction of aqueous solutions of phenol with commercial activated carbons: An adsorption and kinetic study, Carbon 37 (1999) 1065-1074. H.A. Almana, R.M. Mahmoud, Palm date seeds as an alternative source of dietary fibre in Saud bread, Ecology of Food and Nutrition 32 (1994) 261-270. N.Z. Al-Mutairi, 2, 4-Dinitrophenol adsorption by date seeds: Effect of physico-chemical environment and regeneration study, Desalination 250 (2010) 892-901. F. Banat, S. Al-Asheh, L. Al-Makhadmeh, Evaluation of the use of raw and activated date pits as potential adsorbents for dye containing waters, Process Biochemistry 39 (2003) 193-202. M.A. Al-Ghouti, J. Li, Y. Salamh, N. Al-Laqtah, G. Walker, M.N.M. Ahmad, Adsorption mechanisms of removing heavy metals and dyes from aqueous solution using date pits solid adsorbent, Journal of Hazardous Materials 176 (2010) 510-520. A. El Nemr, A. Khaled, O. Abdelwahab, A. El-Sikaily, Treatment of wastewater containing toxic chromium using new activated carbon developed from date palm seed, Journal of Hazardous Materials 152 (2008) 263-275. S.A. Al-Muhtaseb, M.H. El-Naas, S. Abdallah, Removal of aluminum from aqueous solutions by adsorption on date-pit and BDH activated carbons, Journal of Hazardous Materials 158 (2008) 300-307.

[20] B.H. Hameed, J.M. Salman, A.L. Ahmad, Adsorption isotherm and kinetic modeling of 2,4-D pesticide on activated carbon derived from date stones, Journal of Hazardous Materials 163 (2009) 121-126. [21] W.S. Wan Ngah, M.A.K.M. Hanafiah, Adsorption of copper on rubber (Hevea brasiliensis) leaf powder: Kinetic, equilibrium and thermodynamic studies, Biochemical Engineering Journal 39 (2008) 521-530. [22] Standard Methods for the Examination of Water and Wastewater, USEPA 375.4, SulfaVer 4 Method, 1997. [23] F.C. Wu, R.L. Tseng, S.C. Huang, R.S. Juang, Characteristics of pseudo-second-order kinetic model for liquid-phase adsorption: A mini-review, Chemical Engineering Journal 151 (2009) 1-9. [24] Y.S. Ho, Review of second order models for adsorption systems, Journal of Hazardous Materials B 136 (2006) 681-689. [25] C.W. Cheung, J.F. Porter, G. Mc Kay, Sorption kinetics for the removal of copper and zinc from effluents using bone char, Separation and Purification Technology 19 (2000) 55-64. [26] Y. Sag, Y. Aktay, Kinetic studies on sorption of Cr(VI) and Cu(III) ions by chitin, chitosan and Rhizopus arrhizus, Biochemical Engineering Journal 12 (2002) 143-153. [27] Y.S. Ho, G. Mc Kay, Pseudo-second order for sorption processes, Process Biochemistry 34 (1999) 451-465. [28] G. Annadurai, R.S. Juang, D.J. Lee, Use of cellulose wastes for adsorption of dyes from aqueous solutions, Journal of Hazardous Materials 92 (2002) 263-274. [29] M. Özacar, Equilibrium and kinetic modeling of adsorption of phosphorus on calcined alunite, Adsorption 9 (2003)125-132. [30] N. Yeddou Mezenner, A. Bensmaili, Kinetics and thermodynamic study of phosphate adsorption on iron hydroxide-eggshell waste, Chemical Engineering Journal 147 (2009) 87-96. [31] M. Ozacar, Phosphate adsorption characteristics of alunite to be used as a cement additive, Cement and Concrete Research 33 (2003) 1583-1587. [32] A.K. Golder, A.N. Samanta, S. Ray, Removal of phosphate from aqueous solutions using calcined metal hydroxides sludge waste generated from electrocoagulation, Separation and Purification Technology 52 (2006) 102-109. [33] V.E. Osodeke, A.F. Ubah, Sulfate sorption characteristics of some soil of Abia State, Nigeria, Agricultural Journal 2 (2006) 48-51. [34] M.N. Khan, U. Zareen, Sand sorption process for the removal of sodium dodecyl sulfate (anionic surfactant) from water, Journal of Hazardous Materiels B 133 (2006) 269-275.


D DAVID

PUBLISHING

Impact Assessment of Oil Spillage on Farmlands of Some Communities in Ilaje Area of Ondo State, Nigeria O.C. Alaba1 and E.O. Ifelola2 1. Ekiti Rural Water Supply and Sanitation Agency (EKRUWASSA), Ikere-Ekiti, Nigeria 2. Department of Mining Engineering, Federal University of Technology, Akure, Nigeria Received: December 27, 2010 / Accepted: July 1, 2011 / Published: December 20, 2011. Abstract: This study investigated the impact assessment of oil spillage on farmlands of some communities in Ilaje Area of Ondo state. Three farmlands were considered in the course of this study. Two of the three farmlands were within the Ikorigho and Otumara communities that recently experienced oil spillage and they are about 300 m from each other. While the third farm was within the Igbokoda community which is geographically similar but has not experienced oil spillage, it was used as control. The farmland was delineated at each area by the grid technique and soil samples were collected at 0-20 cm depth of the ground. Some physiochemical properties that reflect soil nutrient content and fertility status (pH, electrical conductivity, moisture content, organic matter, nitrogen, phosphorous and cation exchange capacity (CEC)) were determined using standard methods and results from the three areas were compared. There was a significant decrease in the calcium (Ca), magnesium (Mg), potassium (K) and organic matter, as well as a significant increase in the electrical conductivity, moisture content and phosphorous content of the oil-spill affected farmlands at Ikorigho and Otumara when compared with the non-affected farmland at Igbokoda. The acidic nature of the farmlands could not be attributed entirely to the oil spill since the control farmland at Igbokoda was slightly acidic. The results show that oil spillage has adversely affected the nutrient level and fertility status of farmland at Ikorigho and Otumara communities, which needs urgent remediation. Key words: Oil spillage, soil nutrients and fertility, physiochemical properties of soil.

1. Introduction Ikorigho and Otumara communities are located within Ilaje community in the southern part of Ondo State and are one of the oil producing and agro-ecological areas in the Niger-Delta region of Nigeria. The area is blessed with natural resources, which include oil and gas reservoirs, extensive forest, good agricultural land and abundant aquatic culture [1]. The prospecting and exploration of oil involves alteration of land surfaces, clearing of vegetation to make ways for seismic lines and roads, releasing of drilling mud and oils which seep into the soil making them unfit for farming [2]. The most obvious and visible sources of oil spillage in this environment are Corresponding author: O.C. Alaba, master, research field: environmental and safety engineering. E-mail: [email protected].

due to sabotage, corrosion of pipes and storage tanks, carelessness during oil production operations and oil tankers accidents [3]. Oil spills have destroyed most agricultural lands in these communities and have turned productive areas into wastelands. With increasing soil infertility due to the destruction of soil micro-organisms and dwindling agricultural productivity, farmers have been forced to abandon their land, to seek non-existent alternative means of livelihood [4]. Oil spillage restricted soil aeration as oil layer caused a coagulatory effect on the soil, binding the soil particles into water impregnable soil block, which seriously impaired water drainage and oxygen diffusion [5]. Oil spillage affects the physicochemical properties of the soil such as pH, electrical conductivity and nutrient status. The effect of oil spillage may range

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Impact Assessment of Oil Spillage on Farmlands of Some Communities in Ilaje Area of Ondo State, Nigeria

from morphological aberrations, reduction in biomass and stomach abnormalities [6]. Severe oiling of plants may reduce photosynthetic rates, either by interfering with the permeability of the cell membranes or by absorbing the liquid required by the chloroplasts. Affected plant leaves may eventually turn yellow and die [7]. The direct effect of oil spillage on human being apart from its soil devastation is through the food chain [8].

2. Materials and Methods 2.1 Sample Collection The sub-communities where the soil samples for analysis were obtained are Ikorigho and Otumara communities that recently experienced oil-spillage and Igbokoda community which has not experienced oil spillage which was used as the control. From each of the three communities, samples weighing 1-2 kg were randomly collected at depth of 0-20 cm. The samples from each depth were then bulked to obtain a representative sample of the depth of that community. The samples from Ikorigho were labeled as Farm A and those from Otumara as Farm B while those from Igbokoda (the control) as Farm C respectively. 2.2 Laboratory Analysis The representative samples were taken to the Soil Science Laboratory of Department of Crop, Soil and Pest Management, Federal University of Technology, Akure where it was air dried, crushed and finely ground, then sieved through 2.0 mm and stored in plastic bags for analysis to determine the following parameters. pH and electrical conductivity were measured by using a model 3020 pH meter and 4010 Electrical conductivity meter [9]. 20.0 g of air-dried soil sample was put into 50 mL beaker and 20 mL of distilled water was added. The lump of the soil was stirred to form homogenous slurry; the pH meter (3020 Model) and Electrical Conductivity meter (4010 Model) probes were immersed respectively into the sample and allowed to stabilize at 25 oC. The pH and electrical conductivity

values were taken and recorded. Phosphorus (P) was determined by the molybdenum blue color method [10]. Organic matter was analyzed by the wet combustion method [11]. Nitrogen was measured using ASTM D6187-97 procedure. Exchangeable cations (EC) were first extracted by the ammonium acetate extraction method [12]. Then sodium (Na) and potassium (k) were determined using flame photometry while calcium (Ca) and magnesium (Mg) were determined by the Versenate titration method as described by Jackson [12]. Exchange acidity was determined by the titration method using phenolphthalein as indicator. The cation exchange capacity (CEC) was determined by summation of exchangeable base and exchangeable acidity [12].

3. Results and Discussion Table 1 shows the result of the physico-chemical analysis of the soil. 3.1 pH pH measures the acidic and alkaline condition of soil and availability of micro and macronutrient to plants. The soils were acidic at Ikorigho (2.7) and Otumara (3.2) because of the frequent oil spillage in the area that had prevented the leaching of basic salts which is responsible for pH rising. The binding of the oil with soil particulate matter in these samples posed a major resistance to the removal of such basic ions [13]. The soil was slightly acidic at Igbokoda (5.7) which was served as control because of the acidity of the soils of riverline area of Nigeria and is ascribed to the Table 1 Physico-chemical analysis of soil. Soil property pH EC (µs/cm) MC (%) OM (%) N (%) P (mg/kg) Ca (mg/kg) Mn (mg/kg) K (mg/kg) Na (mg/kg)

Farm A 2.7 445 75.63 0.23 1.35 8.67 2.35 0.25 0.10 1.32

Farm B 3.2 570 72.18 0.37 1.43 8.91 1.96 0.23 0.09 1.25

Farm C 5.7 124 31.56 2.06 2.48 5.61 23.61 1.45 0.26 1.08


excessive precipitation which leads to leaching loses of most of the basic cations in the soil. These lost cations are then replaced by hydrogen ion [8]. The pH of these soils have to be adjusted by aeration to complete the microbial oxidation of organic acid while agricultural lime must be added to provide some buffering capacity to the soil [14]. 3.2 Electrical Conductivity (EC)

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be very high following the addition of carbonaceous substance but Table 1 shows clearly that organic matter in Farm A (0.23%) and B (0.37%) were very low when compared with control Farm C (2.06%). This is because the spilled oil had impaired the metabolic processes that would have facilitated the agronomic addition of organic carbon from the petroleum hydrocarbons by reducing the carbon-mineralizing capacity of the micro flora [16]. Table 1 shows that

Electrical conductivity (EC) measures the exchangeable elements that present in the soil matrix. The most common quality of soil measured in terms of EC is salinity. However, the significant effect of oil spillage on the soils of Ikorigho and Otumara when compared with that of the Igbokoda (control) can be observed from Table 1. Farm A and Farm B have high values of electrical conductivity (445 and 570 µs/cm) than control Farm C (124 µs/cm) because the various mineral salts in the spilled oil that covered Farm A and B have dissolved into the soil and increased the soil salinity beyond acceptable level. 3.3 Moisture Content (MC) Moisture content is the amount of water contained in the soil. Table 1 shows significant variation on the moisture content of the soils from 75.63%, 72.18% and 31.56% for the affected soils of farm A and B and the control farm C respectively. This is because Farm A and B had been coated with oil spilled which reduced the water-holding capacity of the soil due to some significant reduction in the bonding property of the soil. The partial coat had resulted to breakdown of soil structure, dispersion of soil particles, which reduces percolation and retention of water, thereby develops severe and persistent water repelling [15]. The high moisture contents in the Farm A and B are responsible for the low microbial activities due to indirect hindrance of spilled oil to the movement of air, which reduce oxygen supply [5]. 3.4 Organic Matter (OM) and Nitrogen (N) The organic matter in the samples was expected to

total nitrogen in the Farm A (1.35%) and B (1.43%) were moderately low when compared with control farm C (2.48%). This could be attributed to low organic matter, high rate of moisture content and soil erosion in the area. Addition of inorganic NPK fertilizer may improve the soil nitrogen of the area [17]. 3.5 Phosphorous Table 1 shows that phosphorous concentration in Farm A (8.67 mg/kg) and B (8.91 mg/kg) are higher when compared with control Farm C (5.61 mg/kg). This is because oil spillage had allowed the fixing of weather minerals in the Farm A and B making less phosphorous available for plants. 3.6 Exchangeable Bases (Cations) Calcium dominated the exchange complex in all the soil samples as shown in Table 1. This is characteristic of strongly weathered tropical soil and is further confirmed by a Ca/Mg ratio of greater than unity in all the samples [18]. The drastic effect of the oil spillage can be seen from the significant difference between the calcium content (2.35 mg/kg) of Farm A and (1.96 mg/kg) of Farm B of the oil spill affected soils and (23.61 mg/kg) of control Farm C respectively. The low calcium status of the oil-spill affected soils would cause poor stem growth and decolouration of crops and thus low crop yield [19]. The effect of the oil spill on potassium (K) content is shown Table 1 from the values of 0.26 mg/kg for the control Farm C and 0.10 mg/kg and 0.09 mg/kg for the oil-spill affected soils of Farm A and B respectively. The values of Farm A and B are less than the critical


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value (0.2 mg/kg) potassium for crop production [17]. According to Atubi and Brady [20, 21], this will retard plant growth, poor stem development and aid wilting. The value of sodium (Na) shows a slight increase in the soil of the oil-spill affected samples of Farm A and B with values of 1.32 mg/kg and 1.25 mg/kg respectively in contrast to 1.08 mg/kg obtained from the control Farm C as shown in Table 1. This implies that oil deposits in the soil tend to increase the sodium content of the soil [6]. This higher proportion of sodium in the soil, despite its being one of the essential trace elements needed by plants, is not an index for effective productivity [22].

[6]

4. Conclusion

[12]

The results obtained from the oil spill affected farms when compared with control farm shows that the soil in Ikorigho and Otumara communities is highly depleted of some important nutrients that are necessary for plant growth. Therefore, the soils require urgent remediation. The problems of oil-spills can be minimized if the oil companies stop to flout environmental regulations in their areas of operations and pay more attention to environmental protection regimes that would have helped to abate oil spill. The government on its part should show commitment in enforcing the minimal environmental laws which it created.

[13]

[7]

[8]

[9] [10]

[11]

[14]

[15]

[16] [17]

References [1]

[2]

[3] [4]

[5]

I.G. Odjuvwuederhie, D. Omoborand, N.F. Adun, The effect of oil spillage on crop yield and farm income in Delta State Nigeria, J. Central Eur. Agric. 7 (2006) 41-48. E.A. Akpofure, M.I. Efere, The adverse effects of crude oil spills in the Niger delta, Urhobo Historical Soc. 4 (2000) 4-7, 13-17. A. Oyem, Christian call for action on Nigerian oil spill, Sage-Oxford’s Christian Environmental Group, 2001. G.O. Anoliefo, D.F. Nwoko, Effects of spent lubricating oil on the growth of Capsicum annum (L.) and Lycopersicon esculentum (miller), Environ. Pollut. 88 (1994) 361-364. A.C. Chindah, S.A. Braide, The impact of oil spills on the ecology and economy of the Niger delta, in: Proceedings of the Workshop on Sustainable Remediation Development Technology, Institute of Pollution Studies, River State University of Science and Technology Port Harcourt, 2000.

[18]

[19]

[20]

[21] [22]

C.T. Odu, Microbiology of soil contaminated with petroleum hydrocarbon, J. Environ. Microbiol 58 (1985) 201-208. L.C. Osuji, Preliminary investigation of mgbede-20oil-polluted site in Niger delta, Nigeria, Chem. Environ. Mgt. 79 (2006) 133-139. C.N. Ngobiri, A.A. Ayuk, I.I. Awunuso, Differential degradation of hydrocarbon fractions during bioremediation of crude oil polluted sites in Niger Delta area, J. Chem. Soc. Nig. 32 (2007) 151-158. G.N. Smith, G.G.N. Smith, Elements of Soil Mechanics, 7th ed., Black Well Science, Oxford, 2001. E.J. Udo, J.A. Ogunwale, Laboratory Manual for the Analysis of Soils, Plant and Water Samples, 1st ed., Department of Agronomy, University of Ibadan, Nigeria, 1978, p. 45. A. Wakley, I.A. Black, Determination of organic carbon in soils, Soil Sci. 37 (1934) 27-38. M.L. Jackson, Soil Chemical Analysis, 1st ed., Prentice Hall, Englewood Cliffs, New Jersery, USA, 1962. A.O. Obi, Relative effects of different N fertilizers on soil pH and crop yield in a western Nigerian soil, Niger. Agric. J. 13 (1976) 95-101. A. Amadi, A. Dickson, Remediation of oil polluted soils: Effect of organic and inorganic nutrient supplements on the performance of maize, Water, Air and Soil Pollution 66 (1993) 59-76. E.N. Oyeike, S.I. Ogbuja, N.M. Nwinuka, Inorganic ion levels of soils and streams in some area of Ogoniland, Nigeria as affected by crude oil spillage, Environ. Monitoring Assessment 73 (2) (2000) 191-204. B.T. Cheng, Soil organic matter as soil nutrient in the soil organic matter studies, Venna 1 (1997) 21-30. E.A. Adenye, V.O. Chude, L.O. Adehusuji, S.O. Oleyiwola, Fertilizer use and management practices for crops in Nigeria, Federal Ministry of Agric. and Rural Development, Abuja, 2002, pp. 5-8. M.A. Olade, Heavy metal pollution and the need for monitoring: Illustrated for developing countries in west Africa, in: C.T.C., K.M. Mean (Eds.), Lead, Mercury Cadmium and Arsenic in the Environment, John Wiley and Sons Ltd., New York, 1987, pp. 335-341. C. Nwilo, O.T. Badajo, Management of Oil Spill along the Nigeria Coastal Areas, 1st ed., University of Lagos Press, Nigeria, 2005. A.O. Atubi, P.C. Onokala, The socio-economic effects of oil spillage on agriculture in the Niger-Delta, J. Environ. Stud. 2 (2006) 50-56. N.C. Brady, R.R. Weil, The Nature and Properties of Soils, 12th ed., Printice-Hall Inc., New Jersey, USA, 1999. R.S. Adams, Some physical and chemical changes in the soil brought about by unsaturation with natural gas, J. Soil Sci. Am. 24 (1960) 41-44.


D DAVID

PUBLISHING

Preliminary Assessment of Total Mercury in Bulk Precipitation around Olkaria Area, Kenya G.N. Wetang’ula1, 2, 3 1. Geothermal Development Company, Nakuru 17700-20100, Kenya 2. United Nations University - Geothermal Training Programme, Grensasvegur 9, Reykjavik 108, Iceland 3. Faculty of Life and Environmental Science, University of Iceland, Sturlugata 7, Reykjavik 107, Iceland Received: April 20, 2011 / Accepted: June 27, 2011 / Published: December 20, 2011. Abstract: Geothermal power plants are receiving increasing attention as regards the mobilization of mercury (Hg) to the environment. Hg is a trace element that may be present in the geothermal fluid, but due to its volatility, it is transferred mainly into the vapor phase. Hence, it may be mostly discharged to the atmosphere with the non-condensable gases. Olkaria geothermal field hosts 3 geothermal power plants. In this area Hg deposition fluxes have not been studied. Concentrations and wet deposition fluxes of total mercury (T-Hg) were determined from April 2009 to May 2010 at 2 sites in this field. Event-based precipitation samples were collected using fabricated bulk precipitation samplers. Samples were treated according to trace metal protocol and analyzed by cold vapor atomic fluorescence spectrometry (CVAFS). This paper thus reports the first ever determination of T-Hg concentrations and fluxes in precipitation. The T-Hg concentration in samples ranged from 0.002-0.0602 µg/L at the two sites, however, the volume-weighted mean concentration and wet deposition flux were 0.01974 and 0.02884 µg·L-1 and 0.0167-1.45 µg·m-2 during the study period. The annual volume-weighted mean wet deposition fluxes of T-Hg for 2 sites were 13.74 and 19.83 µg·m-2·yr-1 with an average flux of 16.785 µg·m-2·yr-1. Hg concentrations and the Hg fluxes in precipitation showed seasonal trends being lowest in the short-rains and highest in the long rains. The concentrations of T-Hg for the 2 sites is negatively correlated with the precipitation depth (r2 = 0.26 & r2 = 0.0065), suggesting that scavenging of particle-bound mercury from the atmosphere is an important mechanism contributing to mercury in rainwater. Mean Hg concentrations in precipitation at the study sites were comparable to the ranges reported for Canada and the USA by the Mercury Deposition Network (MDN). Key words: Olkaria, geothermal, mercury, total mercury, bulk precipiation.

1. Introduction Mercury in the atmosphere can exist as several chemical species including gaseous elemental (Hg), reactive gaseous Hg (RGM) consisting of various oxidized Hg(II) forms in the gas phase, and oxidized particulate-bound Hg(II) species (HgP). Mercury (Hg) from anthropogenic and natural sources is consistently introduced into the terrestrial and aquatic ecosystems, particularly via wet and dry deposition [1]. Wet deposition of Hg is defined as the air-to-surface flux Corresponding author: G.N. Wetang’ula, chief scientist, Ph.D. candidate, main research fields: environmental fluids transport processes (ecotoxicology, air quality modeling, environmental impacts & risk assessment). E-mail: [email protected] or [email protected].

in precipitation (occurring as rain, snow, fog or ice) which scavenges mainly RGM and HgP from the atmosphere, whereas dry deposition is Hg flux in the absence of precipitation and is believed to include the three forms of Hg [2]. Hg is volatile and only slightly reactive, and thus, can be transported over long distances. When it is oxidized to the more water-soluble divalent mercury (Hg2+), it can be easily removed by wet deposition [3]. Hg2+ and HgP, along with dimethyl Hg and methyl Hg, constitute the bulk of Hg in precipitation despite their small concentrations in the atmosphere [4]. Mercury as a trace element is of great concern today because of its inherent toxicity to humans and wildlife, and its propensity to be transported in air long distances from

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Preliminary Assessment of Total Mercury in Bulk Precipitation around Olkaria Area, Kenya

urban and industrial sources. Complex biochemical transformations result in bioaccumulation and toxicity of methyl mercury (MeHg) in many ecosystems [4]. The amount of Hg scavenged by precipitation depends upon mercury speciation, meteorological conditions (type, duration, and amount of precipitation), availability of oxidizing and/or reducing reactants [5], season, transport history of air masses [6] and source locations and characteristics [7, 8]. Mercury in Geothermal Fluids and Its Chemistry: The environmental impact of geothermal power stations is partly related to the atmospheric emission of a significant amount of non-condensable greenhouse gases (NCGs) as well as elements and compounds of toxicological significance which may be dangerous to the environment [9, 10]. The most common toxic gas present is hydrogen sulfide (H2S), however, mercury vapour may also be present. Geothermal power plants are thus receiving increasing attention as regards the mobilisation of mercury to the environment. Mercury is a trace element that may be present in the geothermal fluid, and is transferred mainly into the vapour phase. Due to its high volatility, it may be discharged to the atmosphere with the non-condensable gases. Since the non-condensable gases present in the geothermal fluid are generally characterised by a reducing behaviour, mercury is dominantly emitted as elemental mercury (Hg) [11, 12]. Atmospheric mercury from geothermal fluids may be deposited through both wet and dry processes. To better understand the origins of mercury wet deposition and thereby support the development of effective control strategies, it is necessary to identify their source areas. There have been several attempts to link source locations with precipitation chemistry data [13]. Monitoring of the wet deposition is thus required for the assessment of the environmental risks of mercury. The wet deposition flux is calculated using the concentration determined in precipitation samples and the precipitation amount recorded for each

collection period. In this study, precipitation samples were collected on an event basis. This paper presents the first ever data on total mercury (T-Hg) in bulk precipitation from Olkaria area which currently supports four geothermal power plants namely: (Olkaria I-45 MWe, Olkaria II-105 MWe, Olkaria III-55 MWe, and Oserian plant-5 MWe); floriculture and livestock ranching. This is a unique geothermal area as it also hosts a wildlife conservation ecosystem (Hells Gate National Park & adjacent wild game sanctuaries) with various wild animal species. The area is semi arid though it receives appreciable rainfall and is independent of rivers and streams.

2. Methods and Data 2.1 Sampling Sites The Olkaria geothermal field is located in a multi-centered volcanic complex comprising at least 80 small centres covering an area of approximately 240 km2. It is located in the eastern branch of the African rift system in Kenya about 120 km to the northwest of Nairobi. The mean annual rainfall in the area ranges from 625 to 697 mm (Fig. 1). Its reliability has been poor and unpredictable. The rainfall pattern is bimodal with long rains in March through May and short rains in September to November. Mean monthly maximum temperature varies from 21 to 29 °C while the minimum temperature ranges from 11 to 15 °C [14].

Fig. 1 Rainfall amount of X-2 and Lakeview station from 2000-2009.


A large part of the field is within Hell’s Gate National Park, which is a protected area for wildlife conservation (Fig. 2). The Park attracts large numbers of both local and foreign tourists. Other social and economic activities include private commercial livestock ranches, horticultural and flower farms, wildlife sanctuaries, and domestic livestock keeping by the native Maasai community. The southern shoreline of Lake Naivasha, which is the main source of water for both domestic and commercial uses in this semi-arid region besides being a Ramsar site, is located approximately 5 km from the 105 MWe Olkaria II power station. The X-2 weather station site (198888E 9904665N) is located in the NE sector of the Olkaria geothermal field approximately 0.5-1 km and 3 km from the 105 MWe Olkaria II and 45 MWe Olkaria I Power Stations respectively. The Lakeview site (201231E

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990948N) is located 15 km from the Olkaria geothermal field approximately 1 km from the southern shoreline of Lake Naivasha. There is no industrial activity at the Lakeview site, which would influence measurements at the station, however, agricultural activity mainly horticulture/floriculture farms are in the vicinity. 2.2 Sampling Event-based mercury (Hg) bulk precipitation samples were collected using improvised bulk precipitation samplers for determination of Hg and some major ions from the top of a 1.5 m sampling platform located at the X-2 weather station site and the Kenya Electricity Generating Company Ltd (KenGen) housing estate Lakeview rainfall station. The purpose of the 1.5 m platform was to limit the influence of locally generated soil splash during

Fig. 2 Map of the study area showing sampling sites, Olkaria geothermal power stations and Hells Gate National Park.

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rainfall. The sampling site at X-2 is equipped with meteorological monitoring equipment (manual and automatic weather stations). The sampling components consisted of four polyethylene terephthalate (PET) components: (1) a funnel-15 cm diameter; (2) a connecting tube, acting as a capillary to prevent the diffusion of Hg into the precipitation sample as well as the volatilization of mercury from sample; (3) a sampling bottle (500 mL volume), and (4) a plastic enclosure as a sampling bottle. The sampling components were acid cleaned to prevent possible contamination. A bulk deposition sampling funnel was left uncovered for the entire deployment period. The funnels with a 176 cm2 collection area are commercially available and are equipped with a fine mesh filtering disk to prevent leaves and insects falling into the sample. The receiving bottles were shielded from UV radiation during deployment by wrapping them in two white polyethylene bags secured with rubber bands. Cleaning was conducted according to trace metal clean protocols. All funnels, tubes and bottles were cleaned rigorously by dipping in dilute acid (0.1 N HNO3), rinsing with ultrapure deionized water and then placed in separate plastic bags, stored in plastic boxes until use. Before deployment, 5 mL Hg free trace metal grade HCl were added to the sampling bottle to prevent adsorption and volatilization of mercury after collection. Samples were collected on even based basis, and the sampling components were replaced during sample collection. At the same time, the sample collection was carried out immediately after each rainfall event within a 24 hr period i.e. 0900 hrs when the sun is not hot enough to necessitate sample evaporation. Samples collected at each site were immediately poured into two 100 mL PET bottles, then transported to the laboratory and stored in a refrigerator until analysis. 2.3 Analytical Methods Bulk precipitation samples collected between April

2009 and May 2010 were analysed for total Hg (T-Hg; all forms of Hg in a sample) using Swedish Standard SS-EN ISO 17852:2008 by ALS Scandinavia AB (Lulea, Sweden) as per their final analysis report. The samples were analysed for total mercury (T-Hg) using atomic fluorescence spectroscopy (AFS) according to Swedish Standard SS-EN ISO 17852:2008 [15]. This International Standard specifies a method for the determination of mercury in drinking, surface, ground and rain water using atomic fluorescence spectrometry (AFS). Samples containing mercury at concentrations higher than the working range can be analyzed following appropriate dilution of the sample. The method’s detection limit is dependent on the selected operating conditions and calibration range. The sensitivity of this method is dependent on the operating conditions selected. The bulk precipitation samples were subsampled for immediate analysis of physico-chemical properties and

major

geothermal

anions

in

the

Olkaria

geothermal project Geochemistry Laboratory the results of which are not discussed in this paper. Chloride and sulfate were analyzed for using ion chromatography. Other variable physico-chemical properties (pH, total dissolved solids, conductivity and dissolved

oxygen)

of

the

rain

samples

determined

immediately

upon

Cyberscan

Waterproof

portable

Temperature/TDS/Conductivity

sampling 4-in-1

(Model:

PC

were using pH/ 300

Series) and 3-in-1 pH/Temperature/DO (Model: PD 300 Series) meters.

3. Results and Discussion 3.1 Mercury Concentration in Precipitation Concentrations of total mercury (T-Hg) in precipitation in all samples ranged from 0.002 to 0.0602 µg·L-1 for the two monitoring sites (Lake View and X-2 weather station), with a rainfall volume-weighted mean concentration for the period of 0.01974 ± 0.0153 µg/L and 0.02884 ± 0.0225 µg/L for


the X-2 Meteorological station and the Lakeview Rainfall station respectively (Fig. 3). During the entire sampling period (April 2009 to May 2010), the highest T-Hg concentration (0.0474 µg·L-1) for the X-2 station occurred in April, and was 18 times larger than that of May 2009 (0.0027 µg·L-1), when the lowest T-Hg concentration was observed. At the Lakeview rainfall station which is approximately 15 km from the Olkaria geothermal power stations, the highest T-Hg concentration (0.0602 µg·L-1) occurred in March 2010 and was 30 times larger than that of December 2009 and May 2010 (0.002 µg·L-1), when the lowest T-Hg concentrations were observed (Fig. 3). The Olkaria area experiences two rain seasons i.e. the long rains (March, April and May) and the short rains (Septermber, October and November) as shown in Fig. 1. The seasonal variations of T-Hg in precipitation samples were analysed for the long and short rains. At the X-2 site, the average T-Hg concentration in the long rains samples (0.028187 µg·L-1) was significantly higher than that of the short

Fig. 3 Table 1

Table 2

rains samples (0.00305 µg·L-1 ) (ANOVA Single Factor, p = 0.000104 (Table 1)). At the Lakeview rainfall station, the average T-Hg concentration in the long rains samples (0.03098 µg·L-1) was not signficantly different from that of the short rains (0.0226 µg·L-1 ) samples (ANOVA Single Factor, p = 0.001239 (Table 2)). The spatial distribution of T-Hg concentrations in the precipitation of the two sites (X-2 weather station and Lakeview rainfall station) of the study area did not appear to depict any geographic trend. There were some spatial differences during certain periods, the volume-weighted mean T-Hg concentration at Lakeview in the long rains appeared to be higher than that at the X-2 weather station site. However, there was not enough data for a significance test. Generally, the average annual T-Hg concentrations did not differ markedly between two sites during the entire sampling period i.e. April 2009 to May 2010 (Single Factor ANOVA, p = 0.127946 (Table 3)). Correlation Coefficient (r) analysis revealed that

(a) (b) Total mercury (T-Hg) concentration in precipitation at X-2 and Lakeview stations from April 2009 to May 2010. ANOVA single factor for rainfall and T-Hg concentration at the X-2 station.

Source of variation Between groups Within groups Total

SS 2818.75 1724.20 4542.95

df 1 16 17

MS 2818.753 107.7627

F 26.15704

P-value 0.000104

F crit 4.493998

P-value 0.001239

F crit 4.493998

ANOVA single factor for rainfall and T-Hg concentration at the Lakeview station.


SS 2323.881225 2428.346471 4752.227696

df 1 16 17

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MS 2323.881 151.7717

F 15.31169

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Table 3


ANOVA single factor for T-Hg concentration at X-2 and Lakeview stations.


SS 0.000889 0.005519 0.006408

df 1 16 17

MS 0.000889 0.000345

there was a negative correlation between the monthly concentration of T-Hg and amount of rain for both X-2 and Lakeview sites i.e. r = -0.16 (r2 = 0.026) and r = -0.081 (r2 = 0.0065) respectively (Fig. 4). This may indicate that T-Hg is effectively removed or scavenged from the atmosphere during rainfall though other processes might take place taking into account the variability of the data. 3.2 Factors Influencing the T-Hg Concentration in Precipitation The considerable sample to sample variability observed in the daily event data can be explained largely by variations in meteorological processes and source-receptor relationships that influence the concentrations and deposition of Hg. Studies elsewhere assessing changes in atmospheric deposition over time scales longer than seasons suggest that short term meteorological variability is less significant than long term climatic variability [16]. In our case, the importance of large events appears to be quite significant in controlling levels of Hg deposition in the Olkaria area. During the whole study period, factors affecting Hg concentrations in precipitation have been postulated as being: type of

Fig. 4

F 2.577498

P-value 0.127946

F crit 4.49399842

rainfall event, amount of precipitation, duration of each precipitation event, season and mercury emission sources. 3.3 Mercury Deposition through Precipitation Atmospheric mercury is deposited through both wet and dry processes. Monitoring of the wet and dry deposition fluxes is required for the assessment of the environmental risks of mercury. The wet deposition flux is easily calculated using the concentration determined in precipitation samples and the precipitation amount recorded for each collection period. The individual rainfall event wet deposition fluxes (µg·m-2) were calculated on the basis of the sum of the amounts of mercury (Hg concentration × sample volume) for each rainfall event sample collected during the period. Wet deposition fluxes of T-Hg and amount of rainfall per event are as shown in Fig. 5. The individual rainfall event wet deposition fluxes of T-Hg at each site did not necessarily vary with the amount of rain. However, in some instances T-Hg deposition fluxes were higher during the long rains (March/April/May) than the short rains (September /October /November). The individual rainfall event

(a) Relationship between amount of rainfall and mercury concentration.

(b)


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Precipitation (mm)

Precipitation (mm)

(a) (b) Fig. 5 (a) Individual precipitation events and changes in wet deposition fluxes of total mercury at the X-2 site (April 2009-May 2010); (b) Individual precipitation events and changes in wet deposition fluxes of total mercury at the Lakeview site (April 2009-May 2010).

T-Hg deposition fluxes ranges were 0.0167-1.39 and 0.077-0.294 µg·m-2 for the long and short rains seasons respectively at the X-2 site. While T-Hg deposition fluxes ranges were 0.143-1.45 and 0.08-0.37 µg·m-2 for the long and short rains seasons respectively at the Lakeview site. The annual wet deposition fluxes of T-Hg for the X-2 and Lakeview sites have also been calculated from individual rainfall events, based on the volume weighted mean for the period (Table 4). T-Hg deposition was estimated to range from 13.74 to 19.83 µg·m-2·yr-1 with an average deposition of 16.79 ± 4.3 µg·m-2·yr-1. 3.4 Mercury Comparisons

in

Precipitation

and

Worldwide

In this study a comparison of T-Hg concentrations in precipitation between the Olkaria area (X-2 and Lakeview) and other areas reported in the worldwide literature (Table 5) has also been made. The T-Hg concentrations in precipitation recorded during this study were much higher than those reported for North America and Canada such as in Vermont, USA [16], Table 4

Vermillion Alberta Canada [17], US and Canada NADP Mercury Deposition Network MDN [18], New York, USA [19], and Florida, USA [20], Northernwestern and Central Europe [21], and Wujiang River, China [22]. However, the present concentrations were much lower than in some areas in North America such as Vermont and Davie IFAS Facility Florida [23, 24], Lake Balaton, Hungary [25], and some urban regions in China such as Changchun that had concentration of 354 ng·L-1 [26]. This concentration in precipitation was equivalent to that observed in the Great Lake Region, USA [27]. The mean annual wet deposition fluxes of T-Hg (16.7 µg·m-2·yr-1) and their concentration ranges were comparable to those reported in most literature data. The wet deposition flux of T-Hg in Olkaria area 13-19.83 µg·m-2·yr-1 was comparable to those recorded in Canada /North America and at all MDN sites (1.9-25 µg·m-2·yr-1) in 2008 [28], but much lower than deposition fluxes reported in Changchun Urban centre in China. The annual volume-weighted mean concentration range 19.74-28.84 ng·L-1 T-Hg in Olkaria exceeds the

Annual wet deposition fluxes of T-Hg, and total rainfall during the period.

Site X-2 Lakeview Average ± SD

T-Hg deposition (µg·m-2·yr-1) 13.74 19.83 16.785 ± 4.3

Total rainfall amount during the period (mm) 695.9 687.5 691.7 ± 4.2

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Table 5


Olkaria precipitation Hg concentration and deposition fluxes compared to worldwide literature data.

Location Japan New York, USA Florida, USA Vermont, USA Churchill, Manitoba, Canada Crossfield, Alberta, Canada Vermilion, Alberta, Canada US & Canada, NADP-MDN Newcomb, NY, USA Florida, USA Mace Head, Ireland Sylt island, Germany Langenbrügge, Germany Zingst, Baltic sea Wujiang River, China Underhill, Vermont, USA Florida (Davie IFAS Facility), USA Florida (FAMS Andytown), USA Lake Balaton, Hungary Changchun, China Great Lakes Region, USA Florida (FAMS Andytown), USA Neuglobsow, Germany Zingst, Baltic sea Aspvreten, Sweden Rörvik, Sweden Calabria, Italy Antalya, Turkey Mallorca, Spain Florida, USA Olkaria, Kenya (This study)

Period 2002-2003 2004 1993-1996 1993-2003 2006-2008 2006-2008 2006-2008 1996-2005 2004-2006 1994 1991-1992 1991 1992 1992 2006 1995-2006 1995 1995 2000-2001 1999-2000 1997-2003 1998-1999 1998-1999 1998-1999 1998-1999 1998-1999 1998-1999 1998-1999 1998-1999 1998 2009-2010

Concentration (ng/L) Annual wet deposition fluxes (µg·m-2) 12.8 5.5 5.9 10 20-23 8.9 9.7 1.1-31.7 0.54-2.0 2.1-67.7 0.54-2.0 0.3-27.8 0.54-2.0 10-16 3-25 0.2-28 11.6 12-24 15-30 17 11.4 52 58 36 34.7 0.9-90.5 0.02-0.13 4-82 8-42 5.2-191 354 152.4 10-60 1.2-42.5 4.7-23.3 1.2-109 3.7-80 4 4.2-49.2 7 8.5-30 5.7-53 4.6-75 22-24 0.2-60 13-19.8

2.1-18.7 ng·L-1 at the MDN sites in 2008. For this case the mean annual rainfall range for the Olkaria and MDN sites was 691 mm and 100-2590 mm respectively. The elevated level of T-Hg in precipitation in Olkaria area could be mostly from local and regional sources. Four potential possible sources of T-Hg are thus proposed as a result of this study. The first source is geothermal. In geothermal areas, atmospheric Hg can be introduced into the air by degassing of the earth’s crust, volcanoes, fumaroles, and hot springs [31]. Geothermal steam production from geothermal wells and power plants could enhance natural emissions

Reference [2] [5] [7] [16] [17]

[18] [19] [20] [21] [21] [21] [21] [22] [23] [24] [24] [25] [26] [27] [29] [29] [29] [29] [29] [29] [29] [29] [30]

from geothermal areas. Geothermal power plants are receiving increasing attention as regards the mobilization of mercury to the environment. Mercury is a trace element that may be present in the geothermal fluid, but which, due to its volatility, is favoured by the vapor phase. Hence, it may be mostly discharged to the atmosphere with the non-condensable gases [32]. Geothermal fluid as a source of Hg in atmosphere has been also cited by Ref. [33] in their estimates of global mercury emissions to the atmosphere. On average, volcanoes and geothermal activity release about 90 Mg·yr-1 of mercury to the atmosphere, accounting for nearly 2%


of the total contribution from natural processes [34]. In an 88 MWe geothermal power plant in Piancastagnaio, Italy Hg emission rate of 3-4 g/h/MWe and an Hg concentration in exhaust steam of 1-10 mg/m3 have been reported [35]. The second postulated source are human activties such as burning of biomass in the area which may also contribute to Hg emissions into the atmosphere. Since this is an agricultural area mainly horticulture/floriculture, human-initiated burning of ground cover is commonly employed for land clearing and land-use change. Also disposal of flower cutting trash is effected either by burning and compositing which could cause some Hg emissions to the atmosphere. Mercury can also be released to the atmosphere when the organic matter to which it is bound is burned. Evidence for mercury emissions in biomass burning comes from determinations of mercury in atmospheric plumes that originate from areas of burning. Mercury emissions from biomass burning have only recently been considered in regional and global estimates [36]. The most recent estimate suggests that on a global scale nearly 675 Mg of mercury are released to the atmosphere from biomass burning every year (annual average for the period 1997-2006), which accounts for about 13% of the total contribution from natural sources [36]. The third potential Hg source is mercury from agricultural products such as pesticides and fungicides [37]. Since the area also hosts horticulture/floriculture farming, spraying of the cut flowers against pests and infectious diseases is a daily activity in most flower farms. If the pesticides and insecticides being used contain mercury, this could also be a possible source of mercury emissions into the environment in the area. Escape of mercury from top soils (mercury rich soils or previously deposited Hg) may also be an important process which needs to be taken into account when considering the fourth possible source of mercury in the atmospheric environment that is

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eventually washed down by precipitation. For example in Europe the rate of re-emissions and de-gassing of mercury from soils has been estimated to be in the range of 1.1-1.4 ng·m-2·hr-1 and 26-10,000 ng·m-2·hr-1 in Sweden (forest top soils) and Italy (Mt Amiata mercury rich mineral soils) respectively [29]. Elsewhere mercury fluxes from unaltered or background sites in North America have been found to be in the range 3.7 to 9.3 ng·m-2·hr-1. In altered geologic sites the mean mercury flux was 15.5 ± 24.2 ng·m-2·hr-1 on average, and the highest values, up to 3334 ng·m-2·hr-1, were found where calcine waste had been disposed of [38]. Mercury emissions from top soils are significantly influenced by meteorological conditions, historical atmospheric deposition and the type of top soil. Studies elsewhere have also indicated that small quantities of mercury may be present in motor fuel and lubricating oils [39]. Mercury emissions from automobiles are thought to be negligible in terms of the contribution to mercury levels in precipitation in the present study area because this is a restricted access area and automobiles are very few. Because mercury is never totally removed from the environment as it just moves from one location to another, other distant athropogenic sources might also contribute to the T-Hg in precipitation in the area. For example, if the major atmospheric Hg species is elemental mercury usually in vapour phase, sparing soluble in water, inert to chemical attack by other air contaminants, atmospheric residence time of about one year, enables it to be moved from further away places to new area like the project area, supporting the concept of classifying mercury as a “global pollutant” [40]. The above discussion suggests that on the local scale mercury emissions from the geothermal area (degassing of the earth’s crust, volcanoes, fumaroles), geothermal steam from power production, burning of biomass, and chemical (Hg containing insecticides and fungicides) spraying, escape from top volcanic

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soils and other distant athropogenic sources may contribute to elevated mercury levels in wet deposition in the Olkaria area.

References [1]

4. Conclusions Concentrations and wet deposition fluxes of total mercury in precipitation were determined at 2 sites i.e. X-2 and Lakeview in the Olkaria area, Naivasha, Kenya. The results revealed that there were seasonal variations and spatial differences between concentrations and wet deposition fluxes of T-Hg. T-Hg concentrations during the long rains season (March/April/May) were significantly higher than during the short rains season (September/October/Novemeber). The wet deposition fluxes were higher during the long rains season and correlated well with amounts of precipitation. In general, the concentrations and wet deposition fluxes of T-Hg in the Olkaria area were comparable to similar data cited in literature such as from the National Atmospheric Deposition Program (NADP), Mercury Deposition Network (MDN) in Canada, North America and Europe, but much lower than those concentrations and wet deposition fluxes reported for the Changchun Urban centre in China. The mercury in the wet deposition fluxes observed in the Olkaria area may methylate, bioaccumulate, and subsequently pose a potential risk to wildlife and humans, bearing in mind that the area is a wildlife conservation area (Hells Gate National Park), which is a habitat to several species of wildlife. This study could not pinpoint a single source responsible for elevated precipitation T-Hg concentration in the area.

Acknowledgments This study was funded by Geothermal Development Company through its Environmental Monitoring Programs Fund. Sincere thanks go to Richard Wanjala (Environmental Technician), Kenya Electricity Generating Company, Olkaria Geothermal Project for helping with bulk precipitation sampling.

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10] [11]

[12]

[13]

[14]

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Preliminary Assessment of Total Mercury in Bulk Precipitation around Olkaria Area, Kenya [15] ISO (International Organization for Standardization), Water Quality, Determination of Mercury-Method Using Atomic Fluorescence Spectrometry (ISO 17852:2006), Geneva, Switzerland, 2006. [16] G.J. Keeler, L.E. Gratz, K. Al-wali, Long-term atmospheric mercury wet deposition at Underhill, Vermont, Ecotoxicology 14 (2005) 71-83. [17] H. Sanei, P.M. Outridge, F. Goodarzi, F. Wang, D. Armstrong, K. Warren, et al., Wet deposition mercury fluxes in the Canadian sub-Arctic and southern Alberta, measured using an automated precipitation collector adapted to cold regions, Atmospheric Environment 44 (2010) 1672-1681. [18] E.M. Prestbo, D.A. Gay, Wet deposition of mercury in the U.S. and Canada, 1996-2005: Results and analysis of the NADP mercury deposition network (MDN), Atmospheric Environment 43 (2009) 4223-4233. [19] H.D. Choi, T.J. Sharac, T.M. Holsen, Mercury deposition in the Adirondacks: A comparison between precipitation and throughfall, Atmospheric Environment 42 (2008) 1818-1827. [20] J.L. Guentzel, W.M. Landing, G.A. Gill, C.D. Pollman, Atmospheric deposition of mercury in Florida: The FAMS project (1992-1994), Water, Air and Soil Pollution 80 (1995) 393-402. [21] R. Ebinghaus, H.H. Kock, S.G. Jennings, P. McCartin, M.J. Orren, Measurements of atmospheric mercury concentrations in northwestern and central europe-comparison of experimental data and model results, Atmospheric Environment 29 (1995) 3333-3344. [22] Y. Guo, X. Feng, Z. Li, T. He, H. Yan, B. Meng, et al., Distribution and wet deposition fluxes of total and methyl mercury in Wujiang River Basin, Guizhou, China, Atmospheric Environment 42 (2008) 7096-7103. [23] L.E. Gratz, G.J. Keeler, E.K. Miller, Long-term relationships between mercury wet deposition and meteorology, Atmospheric Environment 43 (2009) 6218-6229. [24] W.M. Landing, J.L. Guentzel, G.A. Gill, C.D. Pollman, Methods for measuring mercury in rainfall and aerosols in Florida, Atmospheric Environment 32 (1998) 909-918. [25] H.L. Nguyen, M. Leermakers, S. Kurunczi, L. Bazo, W. Baeyens, Mercury distribution and speciation in Lake Balaton, Hungary, Science of the Total Environment 340 (2005) 231-246. [26] F.M. Fang, Q.C. Wang, J.F. Li, Urban environmental mercury in Changchun, a metropolitan city in northeastern China: Source, cycle, and fate, Science of the Total Environment 330 (2004) 159-170.

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[27] B.D. Hall, H. Manolopoulos, J.P. Hurley, J.J. Schauer, V.L. St. Louis, D. Kenski, et al., Methyl and total mercury in precipitation in the Great Lakes region, Atmospheric Environment 39 (2005) 7557-7568. [28] National Atmospheric Deposition Program 2008 Annual Summary, NADP Data Report 2009-01, Illinois State Water Survey, University of Illinois at Urbana-Champaign, Champaign, IL, 2009, pp. 11-14, available online at: http://nadp.sws.uiuc.edu/lib/data/2008as.pdf. [29] European Communities, Ambient air pollution by mercury (Hg), Position Paper, in: 17th October 2001 Prepared by The Working Group on Mercury, 2002. [30] J.L. Guentzel, W.M. Landing, G.A. Gill, C.D. Pollman, Mercury and major ions in rainfall, throughfall, and foliage from the Florida Everglades, The Science of the Total Environment 213 (1998) 43-51. [31] F. Baldi, Mercury pollution in the soil and mosses around a geothermal plant, Water, Air and Soil Pollution 38 (1988) 111-119. [32] S. Vitolo, M. Seggiani, Mercury removal from geothermal exhaust gas by sulfur-impregnated and virgin activated carbons, Geothermics 31 (2002) 431-442. [33] N. Pirrone, S. Cinnirella, X. Feng, R.B. Finkelman, H.R. Friedli, J. Leaner, et al., Global mercury emissions to the atmosphere from anthropogenic and natural sources, Atmos. Chem. Phys. 10 (2010) 5951-5964. [34] R.P. Mason, Mercury Emissions from Natural Processes and Their Importance in the Global Mercury Cycle, Springer, New York, USA, Chap. 7, 2009, pp. 173-191. [35] E. Bacci, C. Gaggi, E. Lanzillotti, S. Ferrozzi, L. Valli, Geothermal power plants at Mt. Amiata (Tuscany-Italy): Mercury and hydrogen sulphide deposition revealed by vegetation, Chemosphere 40 (2000) 907-911. [36] H. Friedli, A. Arellano, S. Cinnirella, N. Pirrone, Initial estimates of mercury emissions to the atmosphere from global biomass burning, Environ. Sci. Technol. 43 (2009) 3507-3513. [37] UNEP Chemicals Branch, The Global Atmospheric Mercury Assessment: Sources, Emission and Transport, UNEP- Chemicals, Geneva, 2008. [38] D.M. Nacht, M.S. Gustin, Mercury emissions from background and altered geologic units throughout Nevada, Water, Air and Soil Pollution 151 (2004) 179-193. [39] I. Olmez, M.R. Ames, Atmospheric mercury: How much do we really know?, Pure & Applied Chemistry 69 (1997) 35-40. [40] O. Lindqvist, H. Rodhe, Atmospheric mercury-a review, Tellus Series B-Chemical and Physical Meteorology 37 (1985) 136-159.

D


DAVID

PUBLISHING

Can Industrial By-products Be Used as Tools in Sustainable Agriculture? B. Tóth, L. Lévai and Sz. Veres Department of Agricultural Botany and Crop Physiology, Institute of Plant Sciences, Centre for Agricultural and Applied Economic Sciences, University of Debrecen, Debrecen 4032, Hungary Received: April 20, 2011 / Accepted: June 1, 2011 / Published: December 20, 2011. Abstract: The goal of our study is to present results about the effects of selected industrial wastes—sewage sludge, lime sludge, compost—on the physiological parameters of plants. Maize seedlings (Zea mays L cvs. Norma SC) were used in soil plant (rhizobox) and nutrient solution plant system. The filtrates of the examined materials were used in the nutrient solution and the raw materials in the soil. Dry matter accumulation of shoots and roots, relative chlorophyll contents and the contents of some elements were measured in the plants grown on the nutrient solution. The examined materials contain some useful elements for plants e.g. Cu, Fe, K, and Mg and plenty of toxic metals e.g. Al, Cr. Root growth in the rhizoboxes was monitored, as well as that of roots in the experiment using soil. This type of growth was more intensive with the use of lime sludge than with of sewage sludge. On the other hand, the results were better at the sewage sludge than the lime sludge on the nutrient solution. Key words: Chlorophyll, industrial wastes, plants growth, root.

1. Introduction Phytoremediation involving the use of plants

capable of concentrating trace elements in their harvestable biomasses, thereby offering a sustainable

such as Braccica napus (Cr, Cu, Hg, Pb), Medicago

treatment option for metal-contaminated soils [7]. There is increasing interest in the agricultural application of sludge obtained from wastewater treatment plants, due to the possibility to recycle valuable components: N, P and other plant nutrients [8, 9]. Prior to depositing sewage sludge onto farmlands, it is important to first identity its metal contents, as there is a risk of toxic element accumulating in the soil [10]. Municipal sewage sludge generally contained higher concentrations of heavy metals such as Cu, Pb or Cd than that found in soils [11]. It has been established that low concentration of elements such as Cu, Mo, Ni, Zn, Mn and Fe are essential for plant growth [12]. Above certain levels, these elements become toxic to plants [13].

sativa (Cr) and Helianthus annus (Cr, Pb, Zn) [6] are

There are several strategies available to limit heavy

together with the application of amendments for remediation of a polluted soil is a more natural approach to remediation when compared to some current remediation practices [1-3]. Cunningham and Berti [4] showed that vascular plants remove pollutants from the environment. Plants can absorb metals from soils and sediments through their root/rhizome systems, as a common phenomenon of phytoremediation. Phytoremediation is an effective, low cost, preferred clean up option for moderately contaminated areas [5]. The heavy metal uptake potential largely varies with plant species, metal availability in the system and other environmental conditions. Hyperaccumulator plants,

metal uptake by plants [14]. CaCO3 application Corresponding author: B. Tóth, pre-doctor, main research fields: physiological examination of industrial by-products. E-mail: [email protected].

increased the pH of soil amended with sludge, which reduced metal uptake by rice, wheat and cabbage [15].

1597

Can Industrial By-products Be Used as Tools in Sustainable Agriculture?

Liming is being applied as a management tool to immobilize heavy metals in soils, biosolids and mine tailings, thereby reducing their availability for plant uptake and leaching into ground water.

2.2 The Element Contents of the Examined Materials The element contents of materials were determined using

an

OPTIMA

3300

DV

ICP-OA

Spectrophotometer. 10 mL HNO3 (65v/v%) were added to each gram of the samples for overnight

2. Methods and Data 2.1 Nutrient Solution Experiment—Growth of Plants

incubation. Then, the samples were pre-digested for 30 min at 60 °C. Finally, 3 mL H2O2 (30 m/m%) were

Maize (Zea mays L cvs. Norma SC) seedlings were

added for a 90 min boiling at 120 °C. The solution was

used in the experiments. After surface sterilization,

filled up to 50 mL, homogenised and filtered through

seeds were then soaked in 10 mM CaSO4 for 4 hours

MN 640 W filter paper.

o

and then germinated on moistened filter paper at 25 C. The seedlings were transferred to a continuously

2.3 Relative Chlorophyll Contents

aerated nutrient solution of the following composition:

The relative chlorophyll contents were investigated

2.0 mM Ca(NO3)2, 0.7 mM K2SO4, 0.5 mM MgSO4,

using a Chlorophyll Meter, SPAD-502 (Minolta). The

0.1 mM KH2PO4, 0.1 mM KCl, 1 µM H3BO3, 1 µM

relative chlorophyll contents of the 2nd and 3rd leaves

MnSO4, 10 µM ZnSO4, 0.25 µM CuSO4, 0.01 µM

of the maize were measured. The number of repetitions

(NH4)6Mo7O24. Iron was added to the nutrient solution

was 60.

as Fe(III)-EDTA at a concentration of 10 μM. For different treatments, 91, 100 and 66 mL·dm-3 of

2.4 Dry Matter Accumulation

compost, lime sludge and sewage sludge were added to

The dry matter of shoots and roots were measured

the nutrient solutions, respectively. The filtrates were

with the use of thermal gravimetric analysis, after

made from 17 g examined materials and 170 mL

drying at 85 ºC for 48 h.

distilled water. The prepared solutions were shaken for 2 hours and then vacuum filtrated. The seedlings, 12

2.5 Rhizobox Experiment

for each basic treatment, were grown under controlled

Calcareous chernozem soil was collected from a

environmental conditions (light/dark regime 10/14 h at

depth 0-30 cm. 245 g of soil were placed into the each

24/20

o

C, relative humidity of 65-70% and a -2 -1

rhizobox and 5g of the

investigated materials

photosynthetic photon flux of 300 μmol m ·s ) in

(compost, sewage sludge, lime sludge). The control

growth chamber. The volume of experiment pots were

contained 250 g soil. The soil

1.7 L, with one pot containing 5 plants. The pH of the

50% of field capacity, i.e. 19 mL of distilled water

control nutrient solution was 4.4. The sewage sludge and compost originated from poppy shell-based alkaloid production (ALKALOIDA Chemicals Co. Ltd.). The sewage sludge was mixed into various kinds of shavings, as bulking agents, and used as a covering material for waste rock piles. The lime sludge comes from metallurgical waste transformer plant (Ore, Mineral and Waste Recycling Works of The Borsod Limited Share Company).

were used per rhizobox. Each rhizobox contained 3

was

moistened to

plants. The number of repetitions was three per treatment. The applied soil characteristic parameters were the pHKCl 5.71, pHH2O 6.58. The content of CaCO3 was 0.202%, the humus content was 3.54%. The contents of the main elements of the soil were the following: 332 mg·kg-1 from Na, 176 mg·kg-1 from Mg, 6.04 mg·kg-1 from S, 5.79 mg·kg-1 from Cu, 7.9 mg·kg-1 from Zn and 262 mg·kg-1 from Mn.

1598


3. Results and Discussion To know the soluble portion of applied by-products, the contents of elements were determined in water filtrates of raw material (Table 1). These materials contain many useful elements for plants (e.g. iron, potassium, zinc or magnesium) and some harmful ones also (e.g. aluminum, chrome). Metal toxicity is usually connected with low soil pH in cultivated plants. Acidity increases the availability of aluminium, manganese, and iron, which are abundant in mineral soils. The pH of lime sludge is very alkaline (10.77), the pH of sewage sludge is 8.83, while this value is 8.79

for

the

compost

material.

The

largest

concentration of Al, Fe and Mn were measured in the lime sludge. The quantity of aluminium was approx 46.5 times higher in the lime sludge than in the sewage sludge. The amount of iron was 4.5 times higher in the lime sludge than in the compost. This value was about 4 times higher in the case of manganese. The content of chromium was the highest in the lime sludge. The average content of chromium in the soil is 50-1,000 mg·kg-1 [16]. Thus, the quantity of Cr in the examined materials is outside this range. The quantity of sodium was very high in all the examined materials. This value was more than 900 mg·kg-1 in the lime sludge. This amount was two times higher than that in the compost and four times higher than that found in the sewage sludge. The contents of

elements were also measured in the raw materials because these were used for the rizobox experiment (Table 2). The contents of elements were higher in the raw materials than in the filtrates. The highest concentration of Cr, Cu, Fe and Na were measured in the lime sludge. The highest quantities of Al, K, Mg, P, Sr and Zn were measured in the sewage sludge. Plants can uptake these elements which may cause different effects on their growth and development. Therefore, we examined the amounts of selected up-taken elements in the roots and shoots of maize (Table 3). Larger concentrations of aluminium were measured in the roots than in the shoots. We suppose that the Al was accumulated in the roots and the root-to-shoot transfer is retarded. The Al concentrations were highest in the roots of treated plants and as a consequence, the observed growth of the shoots and roots was greater than that of the control. The concentrations of Al were about 23 times higher in the maize treated by compost than in the control. The investigated materials have effect on pH. When compost was added to the nutrient solution pH increased with 0.65, this pH value for the sewage sludge was 0.85, in comparison to the control. The pH was increased by 2.23 with the lime sludge. The toxic effects of aluminium are primarily root-related [17]. The root system becomes stubby as a result of

Table 1 Contents of some elements in the water filtrates of the examined wastes (compost, lime sludge, sewage sludge) (mg·kg-1). Examined materials Compost Lime sludge Sewage sludge

Al 31.40 219.00 4.71

Cr 0.46 1.34 0.57

Cu 0.48 0.61 0.11

Fe 53.50 241.00 64.40

Examined elements (mg·kg-1) K Mg Mn 419.00 728.00 2.79 108.00 153.00 4.91 167.00 190.00 1.15

Na 452.00 924.00 218.00

P 62.50 1.84 6.20

Sr 6.09 0.67 1.50

Zn 1.80 2.88 0.69

Table 2 Contents of some elements in the raw materials of the examined wastes (compost, lime sludge, sewage sludge) (mg·kg-1). Examined materials

Al Compost 7,227 Lime sludge 3,440 Sewage sludge 17,349

Cr 25.50 169.00 41.30

Cu 53.00 185.00 109.00

Fe 9,883 118,500 21,098

Examined elements (mg·kg-1) K Mg Mn 1,485 3,693 337 1,010 5,055 1,983 2,878 5,548 496

Na 1,475 5,419 2,163

P 10,063 162 21,289

Sr 102.00 157.00 195.00

Zn 251.00 106.00 473.00

1599


Table 3 The concentration of examined elements (Al, Cr, Cu, Fe, Na, Sr, Zn) in the roots and shoots of maize (mg·kg-1) affected by compost, sewage sludge, lime sludge. Examined materials

Al Cr Control 62.43 2.91 Compost 1,486 6.00 Sewage sludge 242.66 1.67 Lime sludge 717 19.56 Control Compost Sewage sludge Lime sludge

23.07 20.83 13.29 10.57

0.72 0.39 0.73 0.65

Examined elements in the roots of maize (mg·kg-1) Cu Fe K Mg Mn Na 24.43 264 63,865 5,224 260 1,407 33.63 1,051 61,347 5,544 803 1,221 23.96 357 65,470 5,760 274 1,018 30.26 602 61,838 4,991 343 1,121 Examined elements in the shoots of maize (mg·kg-1) 16.06 71.86 76,739 2,302 73.30 217 16.16 73.80 65,551 2,265 92.20 254 16.96 63.60 84,928 2,444 82.33 259 15.43 57.43 78,496 2,115 73.46 234

inhibition of elongation of the main axis and lateral roots [18]. The severity of inhibition of root growth is a suitable indicator of genotypic differences in aluminium toxicity [19]. The contents of chromium were also higher in the roots than in the shoots. These values were below the control in the shoots when compost and lime sludge were added to the nutrient solution. The amount of copper was higher, approximately twice that found in the roots than in the shoots, when the compost and the lime sludge were examined. This value increased by 1.5 at the control and the sewage sludge. For most crop species, the critical toxicity level of copper in the leaves is above 20-30 μg·g-1 dry weight [20]. There are, however, marked differences in copper tolerance between plant species (e.g. bean is much more tolerant than corn); these differences are directly related to the copper content of the shoots [21]. The concentration of iron was about the control level in the shoots of treated plants. Larger concentration was measured in roots. The amount of iron was approx 4.5 times higher in the roots of maize treated with the compost and twice as high in the lime sludge treatment. Iron toxicity is a serious problem in crop production on waterlogged soils; it is the second most severe yield-limiting factor in wetland rice [22]. The critical toxicity contents are above 500 mg·Fe·kg-1 leaf dry weight, but this is very much dependant on other factors, such as the contents of

P 10,313 12,678 8,885 8,490

Sr 8.91 10.70 6.70 6.92

2,524 12,292 11,429 10,249

6.26 7.25 6.70 5.04

Zn 159 143 126 108 89.10 63.73 69.96 59.53

other mineral nutrients [23]. Iron toxicity may also play a role under dry land conditions and is probably an early event of drought-induced damage in photosynthetic tissue caused by iron-catalyzed formation of oxygen free radicals in the chloroplast [24]. The content of sodium in shoots was the highest in the control, compared to the otherwise treated plants. The concentration of Na increased in the roots when plants were treated with the compost, sewage sludge and lime sludge. The application of the sewage sludge increased the amount of Na by approximately 42 mg·kg-1, the compost by 37 mg·kg-1 and the lime sludge by 17 mg·kg-1. According to Johnston et al. [25], the supply of 100 μM Na+ enhanced growth and alleviated the visual symptoms and sodium may be classified as a mineral nutrient for at least some of the C4 species in the families [26]. However, the conclusion of Brownell [26] that sodium is essential for higher plant species in which the C4 pathway is operative is not justified. In all these studies, C4 species, such as maize, have not been included, i.e. species which are typically natrophobic and have similar growth rates in the absence and presence of sodium supply [27]. According to present knowledge sodium is essential for many, but not all C4 species, and it is not essential for C3. The content of zinc was approximately two times higher in the roots than in the shoots in all cases. The largest concentration Zn was measured in the control

1600


than in the treated plants. The amount of zinc decreased in the shoots by approximately 25 mg·kg-1 when plants were treated with compost, by 20 mg·kg-1 when treated with the sewage sludge treatment and approximately with 30 mg·kg-1 when the lime sludge was added to the nutrient solution. The critical toxicity levels in the leaves of crop plants are from as low as 100 μg·Zn·g-1 dry weight [28] to more than 300 μg·Zn·g-1 dry weight, the latter values being more typical. Increasing soil pH by liming is the most effective procedure for decreasing both zinc content and zinc toxicity in plants [29]. The heavy metal toxicity may decrease growth, so the dry matter accumulation of shoots and roots of maize were measured during the experiments (Table 4). In nearly all the cases, the dry matter accumulation values were found around the control value, except for the compost, for which the dry matter accumulation of roots and shoots were below the control level. The dry matter accumulation of the roots decreased by 15.6 mg and the dry matter accumulation of the shoots by 8.6 mg when the compost was added to the nutrient

solution. There were no significant differences in comparison to the control. The dry matter contents of roots increased by 2.5 mg when the lime sludge was added to the nutrient solution and by 20 mg when the sewage sludge was. The dry matter accumulation of shoots increased by 43 mg in the lime sludge treatment and by 93 mg in the sewage sludge. The dry matter production nutrient supply curve has three clearly defined regions. In the first, the growth rate increases with increasing nutrient supply. In the second, the growth rate reaches a maximum and remains unaffected by nutrient supply. In the third, the growth rate falls with increasing nutrient supply. Low chlorophyll contents affect photosynthetic activities. The decreasing dry matter accumulation can be explained by the lower level of the chlorophyll contents (Table 5). The compost, sewage sludge and lime sludge contain some iron (content of iron in the compost: 9,883 mg·kg-1; the content of iron in the sewage sludge is 21,098 mg·kg-1; and this value is 118,500 mg·kg-1 in the lime sludge).

Table 4 Effects of different matters (compost, lime sludge, sewage sludge) on the dry matter accumulation of shoots and roots of maize seedlings (mg·plant-1). Examined materials

Dry matter of shoots and roots (mg·plant-1) Roots

Shoots

Control

101.5 ± 0.05

318.2 ± 0.11

Compost

85.9 ± 0.02

309.6 ± 0.13

Lime sludge

104.0 ± 0.01

361.8 ± 0.02

Sewage sludge

121.6 ± 0.04

411.2 ± 0.10

Table 5 Relative chlorophyll contents of the 2nd and 3rd leaves of corn in the measurements taken on the 6th, 9th and 11th days (Spad Units). Significant difference in comparison to the control: *p < 0.05; **p < 0.01. Examined materials Control Compost Lime sludge Sewage sludge

6th day 38.14 ± 4.95 41.26 ± 5.82 38.10 ± 4.78 34.07 ± 7.75

Control Compost Lime sludge Sewage sludge

30.06 ± 6.06 32.11 ± 6.85 33.69 ± 3.64 32.13 ± 5.19

2nd leaves of maize 9th day 48.20 ± 2.85 43.07 ± 4.68* 44.05 ± 2.08 47.27 ± 4.08 3rd leaves of maize 43.43 ± 2.49 38.85 ± 3.50** 42.88 ± 3.39 41.77 ± 4.60

11th day 49.31 ± 5.12 47.37 ± 3.60 47.40 ± 2.86 47.92 ± 4.10 45.87 ± 1.98 44.83 ± 3.27 47.71 ± 1.62 46.75 ± 4.30


1601

Table 6 Effects of examined materials (compost, sewage sludge, lime sludge) on the daily and nightly growth of roots of maize (mm). Examined materials Control Compost Lime sludge Sewage sludge

Daily 18.266 ± 7.28 21.142 ± 6.39 19.714 ± 7.55 18.531 ± 7.04

The relative chlorophyll content increased in the 2nd leaves of maize when compost was applied on the 6th day. The relative chlorophyll contents decreased in the sewage sludge on the 6th day. These values decreased in the 2nd leaves of the treated plants on the 9th and 11th days. The relative chlorophyll contents decreased significantly in the 2nd and 3rd leaves on the 9th day. The chlorophyll contents of 3rd leaves were lower than those in the 2nd leaves. The relative chlorophyll contents of the 3rd leaves decreased by 9 Spad Units in the compost treatment on the 6th day. These values were 4.5 Spad Units in the lime sludge and approximately 2 Spad Units in the sewage sludge. The decease was not so considerable on the 9th and 11th days. The major function of magnesium in green leaves is its role as the central atom of the chlorophyll molecule. The proportion of the total magnesium bound to chlorophyll depends very much on the magnesium supply [30]. Depending on the magnesium nutritional status, between 6% and 25% of the total magnesium is bound to chlorophyll. In most instances, growth is depressed and visual symptoms of magnesium deficiency occur when the proportion of magnesium in the chlorophyll exceeds 20-25%. Photosynthesis is strongly inhibited even by 5 mM magnesium in the external solution [31]. After the examination of the nutrient solution the plant-soil system was also examined. The growth and length of roots were measured (Table 6). Root growth was more intensive at night than in the daytime. There were no significant differences in comparison to the control. Root length increased by approximately 3 mm in the compost in the daytime

Growth of roots (mm) Nightly 21.931 ± 8.64 23.777 ± 5.97 21.928 ± 7.12 22.218 ± 7.31

periods and approximately 2 mm in the nighttime periods. The growth of roots was around that of the control in the lime sludge treatment in the nighttime period and increased 1.5 mm in the daytime period in comparison with the control. This value was around that of the control in the sewage sludge in the daytime period and somewhat increased in the nighttime period. Calcium plays a key role in protecting root growth against low pH stress. The calcium requirement for root growth is not fixed but is rather a function of both pH and the concentration of other cations, including aluminum. On average, a molar ratio of calcium to total cations of 0.15 is needed in the soil solution for maximum root growth. The lime sludge contains 278,400 mg·kg-1 calcium, the sewage sludge 123,988 mg·kg-1. The growth of roots increased significantly in the daytime when the lime sludge was used and at night when the compost was applied.

4. Conclusions The investigated materials contain lots of elements. The larger concentration of Al, Cr, Cu, Fe, Mn, Na and Zn were measured in the lime sludge than in compost or sewage sludge. Highest concentration of K, Mg and P were measured in the compost. The plants take up these elements which may cause different effects on their growth and development. The amount of up-taken elements also was measured. Of the examined elements, larger concentration was measured in the roots than in the shoots. This is advantageous for crop production because we especially use the shoots of crop plants. The dry matter production, which is the main aim of crop production, depends on nutrient supply. The investigated materials

1602


also contain many useful elements for plants, which are essential for growth. Dry matter accumulation of roots increased by 2.5 mg when the lime sludge was added and 20 mg when the sewage sludge was added to the nutrient solution. The dry matter accumulation of shoots increased by 43 mg in the lime sludge and 93 mg in the sewage sludge. These results suggest the potential application of lime sludge and especially sewage sludge as nutrient supplementary materials in crop production. Further examinations are needed to examine the potential and combined application in fields.

[11]

[12]

[13]

[14]

References [1]

P. Burgos, A. Pérez de Mora, E. Madajon, F. Cabrera, Assisted natural remediation of trace element polluted soils, Sustainable Organic Waste Management for Environmental Protection and Food Safety 2 (2005) 65-68. [2] D.J. Walker, R. Clemente, A. Roig, M.P. Bernal, The effects of soil amendments on heavy metal bioavailability in two contaminated Mediterranean soils, Environmental Pollution 122 (2003) 303-312. [3] D.J. Walker, R. Clemente, M.P. Bernal, Contrasting effects of manure and compost on soil pH, heavy metal availability and growth of Chenopodium album L. in a soil contaminated by pyritic mine waste, Chemosphere 57 (2004) 215-224. [4] S.D. Cunningham, W.R. Berti, Remediation of contaminated soils with green plants: An overview, In Vitro Cell Dev. Biol. 29 (1993) 207-212. [5] S.J. Weis, P. Weis, Metal uptake, transport and release by wetland plants: Implications for phytoremediation and restoration, Environment International 30 (2004) 685-700. [6] S. McCutcheon, Schnoor, Phytoremediation, John Wiley & Sons, New Jersey, 2003, p. 19. [7] R. Tappero, E. Peltier, M. Grafe, Hyperaccumulator Alyssum murale relies on a different metal storage mechanism for cobalt than for nickel, New Phytology 175 (2007) 641-654. [8] J.L. Smith, Cycling of nitrogen through microbial activity, in: J.L. Hatfield, B.A. Stewart (Eds.), Advances in Soil Sciences, Lewis Publishers, Boca Raton, 1994, pp. 91-120. [9] J.W.C. Wong, K.M. Lal, D.S. Su, M. Fang, Availability of heavy metals for Brassica chinensis grown in an acidic loamy soil amended with domestic and industrial sewage sludge, Water Air Soil Pollut. 128 (2001) 339-353. [10] M. Angelidis, R.J. Gibbs, Chemistry of metals in

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anaerobically treated sludges, Water Research 23 (1989) 29-33. R.L. Chaney, Health risk associated with toxic metal in municipal sludge, in: G. Bitton, B.L. Damron, G.T. Edds (Eds.), Ann Arbor Science, Ann Arbor, MI, USA, 1980, pp. 59-83. R.D. Reeves, A.M.J. Baker, Metal-accumulating plants, in: I. Raskin, D. Ensley (Eds.), Phytoremediation of Toxic Metals Using to Clean Up the Environment, John Wiley and Sons, New York, 2000, pp. 193-230. M.J. Blaylock, J.W. Huang, Phytoremediation of toxic metals, in: I. Raskin, D. Ensley (Eds.), Phytoremediation of Toxic Metals: Using Plants to Clean up Environment, John Wiley and Sons, New York, 2000, pp. 53-70. S. Kuo, E.J. Jellum, A.S. Baker, Effects of soil type, mining and sludge application on zinc and cadmium availability to Swiss chard, Soil Science 139 (1985) 122-130. H.N. Chen, C.R. Zheng, C. Tu, Z.G. Shen, Chemical methods and phytoremediation of soil contaminated with heavy metals, Chemosphere 41 (2000) 229-234. A.M. Zayed, N. Terry, Chromium in the environment: Factors affecting biological remediation, Plant Soil 249 (2003) 139-156. G.J. Taylor, The physiology of aluminum phytotoxicity, in: H. Sigel, A. Sigel (Eds.), Metal Ions in Biological Systems, Marcel Dekker, New York, 1988, pp. 123-163. F. Klotz, W.J. Horst, Genotypic differences in aluminum tolerance o soybean (Glycine max. L.) as affected by ammonium and nitrate-nitrogen nutrition, J. Plant Physiol. 132 (1988) 702-707. C.D. Foy, A.L. Fleming, G.R. Burns, W.H. Armiger, Characterization of differential aluminium tolerance among varieties of wheat and barley, Soil Sci. Soc. Am. Proc. 31 (1967) 513-521. A.D. Robson, D.J. Reuter, Diagnosis of copper deficiency and toxicity, in: J.F. Loneragan, A.D. Robson, R.D. Graham (Eds.), Copper in Soils and Plants, Academic Press, London, 1981, pp. 287-312. G. Bachthaler, A. Stritesky, Wachstumsuntersuchungen an Kulturpflanzen auf einem mit Kupfer überversorgten Mineralboden, Bayer. Landwirtsch. Jahrb. 50 (1973) 73-81. G.J.D. Kirk, A.R. Ahmad, P.H. Nye, Coupled diffusion and oxidation of ferrous iron in soils. II. A model of the diffusion and reaction of O2, Fe2+, H+ and HCO3- in soils and a sensitivity analysis of the model, J. Soil Sci. 41 (1990) 411-431. M. Yamauchi, Rice bronzing in Nigeria caused by nutrient imbalances and its control by potassium sulfate application, Plant Soil 117 (1989) 275-286. A.H. Price, G.A.F. Hendry, Iron-catalysed oxygen radical


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formation and its possible contribution to drought damage in nine native grasses and three cereals, Plant Cell Environ. 14 (1991) 477-484. M. Johnston, C.P. Grof, P.F. Brownell, The effect of sodium nutrition on the pool sizes of intermediates of the C4 photosynthetic pathway, Aust. J. Plant Physiol. 15 (1988) 749-760. P.F. Brownell, Sodium as an essential micronutrient element for plants and its possible role in metabolism, Adv. Bot. Res. 7 (1979) 117-224. E.J. Hewitt, Essential and functional methods in plants, in: A. Robb, W.S. Pierpoint (Eds.), Metals and Micronutrients: Uptake and Utilization by Plants’ 8D, Academic Press, New York, 1983, pp. 313-315. A. Ruano, Ch. Poshenrieder, J. Barcelo, Growth and

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biomass partitioning in zinc-toxic bush beans, J. Plant Nutr. 11 (1988) 577-588. [29] M.C. White, A.M. Decker, R.L. Chaney, Differential cultivar tolerance in soybean to phytotoxic levels of soil Zn. I. Range of cultivar response, Argon. J. 741 (1979) 121-126. [30] G. Michael, Über die Aufnahne und Verteilung des Magnesiums und dessen Rolle in der höheren grünen Pflanze, Z. Pflanzenernaehr, Dueng. Bodenkd. 25 (1941) 65-120. [31] W. Wu, J. Peters, G.A. Berkowitz, Surface charge-mediated effects of Mg2+ on K+ flux across the chloroplast envelope are associated with regulation of stromal pH and phototsynthesis, Plant Physiol. 97 (1991) 580-587.

D


DAVID

PUBLISHING

Trace Metals in Sediments, Macroalgae and Benthic Species from the Western Part of Algerian Coast W. Benguedda1, N. Dali youcef1 and R. Amara2 1. Department of Ecology and Environment, University of Tlemcen, Tlemcen 13000, Algeria 2. Department of Biology, University of Littoral-Opale Coast, Wimereux 62930, France Received: May 4, 2011 / Accepted: June 22, 2011 / Published: December 20, 2011. Abstract: The concentrations of Cd, Pb, Cu and Zn were measured in sediments and specimens of four marine organisms: green algae (Enteromorpha linza), red algae (Corallina officinalis), mollusc limpet (Patella ferruginea) and sea urchin (Paracentrotus lividus). The samples were collected at four coastal stations located in two areas in the North-Western Algerian coast: Ghazaouet and Beni-saf. These areas are influenced by anthropogenic activities (harbour and industrial and urban wastes). Metal concentrations measured in sediments and biota indicated that the area of Ghazaouet was the most polluted. We found high variability of metal bioaccumulation among the four species analysed. The highest concentrations were recorded in the algae whereas metal concentrations in sea urchin and limpet were more correlated with sediments metal concentrations. Key words: Trace metals, sediment, marine algae, benthic species, Algeria.

measure many of these compounds qualitatively and

1. Introduction Metals are ubiquitous in the environment. Metal presence occurs in both natural and anthropogenic forms. While natural forms are present at relative low concentrations,

in

recent

anthropogenic

sources

years have

a

number

implied

of

notable

contributions to the increase of environmental concentrations [1, 2]. Urban and industrial activities introduce large amounts of pollutants into the marine environment, causing significant and permanent disturbances in marine systems and, consequently, environmental and ecological degradation. This phenomenon is especially significant in the coastal zones that are the main sinks of almost all anthropogenic discharges of pollutants [3]. The analysis of environmental matrices such as water or sediments provides a picture of the level of pollution. Although chemical analyses are able to

quantitatively, complex mixtures of these chemical pollutants cannot be fully assessed. Furthermore, chemical analyses alone do not reveal the impact of chemical pollution on the aquatic environment because of potential

synergistic/antagonistic effects of

complex mixtures of chemical pollutants. The use of biological species in the monitoring of marine environment quality allows evaluating the biologically available levels of contaminants in the ecosystem or the effects of contaminants

on living organisms

[4, 5]. Many marine organisms such as macroalgae [6], mollusc [7], fish [8] or crustaceans [9] have been used to assess the degree of metal pollution. As even closely related species may exhibit different accumulation strategies for trace elements, there is a need for interspecific

comparison

of

accumulated

metal

concentrations [6-10]. The present study aims to determine the levels of

Corresponding author: N. Dali youcef, Ph.D., main research field: environmental chemistry. E-mail: [email protected].

heavy metals (Pb, Cd, Zn and Cu) in sediments and four marine benthic organisms (green algae, red algae,

Trace Metals in Sediments, Macroalgae and Benthic Species from the Western Part of Algerian Coast

sea urchin and limpet) from the coastal areas of the western Algerian coast. Besides their widespread distribution over the Algerian and Mediterranean coastal areas, these species meet some additional criteria of ideal biomonitors, being sessile or sedentary, available all year long, and easy to sample. Another important requirement is the unambiguous taxonomic. Four selected sites have been chosen to elucidate the relationship between the location of industries and other polluting centres and the heavy metals contamination. The aim of this study was also to compare metal concentration between species (algae, sea urchin and limpet) and to analyse their relationship with metal concentrations in the sediment.

2. Materials and Methods 2.1 Study Area Two areas in the North West of Algerian coast characterized by different coastal anthropogenic pressure were investigated (Fig. 1). The first area was located at Ghazaouet, a city of about 42,000 inhabitants which is situated at approximately 10 km from Morocco. In this area, an important harbour constitutes an anchoring point on the coastal for all the North West of Algeria. Coastal waters of this area are continuously exposed to industrial, urban and agricultural wastes including a large number of metal ions especially Zn and Cd coming from a large industrial complex of electrolysis of Zn surrounding the harbour of Ghazaouet. Two stations were analysed in this area, one station inside the harbour (station B) and the other east of the beach (station A). The second sampling area is situated at Beni-Saf, at approximately 80 km east of Ghazaouet (Fig. 1). It is a city of 45,688 inhabitants characterized by its fishing and commercial harbour, its ancient iron-mine and a large variety of industries (cement, a cannery of fishes etc.). Two stations were analysed in this area: one station inside the harbour (station C) and the other east of the beach (station D).

1605

2.2 Sampling Samples of sediments, green algae (Enteromorpha linza), red algae (Corallina officinalis), mollusc limpet (Patella ferruginea), and sea urchin (Paracentrotus lividus) were collected in the four stations. At each station, 36 samples were taken for the analyses. Sediments samples were taken at a depth of 5 cm. Algae, limpets and sea urchins were caught by pulling up. After collection, the samples were placed in polyethylene bags and were transported to the laboratory in icebox. 2.3 Heavy Metals Analysis Sediment and algae samples were air dried for one week until to constant weight and crushed using an agate mortar to obtain a fine powder, followed by separation through a sieve to obtain the lower fraction (< 63 μm). Each kind of these samples was prepared for a mineralisation with acid attack. An acid mixture of (HF + HCl + HNO3) for sediment and of (HClO4 + HCl + HNO3) for algae respectively in proportion 1:6:2 (v:v:v) were used to digestion. The protocol of mineralization used in our investigation was proposed in Refs. [11, 12]. Samples of Patella ferruginea and Paracentrotus lividus were removed from rocks with knife made of the steel of the rustproof. With the help of a scalpel one withdraws the soft part of the shell. In this paper, Paracentrotus lividus and Patella ferruginea will be respectively referred to sea urchin and limpet. 3 to 4 g of soft part of the whole animal of sea urchin and limpet were treated by acid mixture HClO4 + HNO3 (volume ration of 5:1) at 70 °C during 12 hours [13]. Extracts were then filtered through 0.45 µm Millipore membrane filters and acidified with 50 µL of HNO3. Acids exhibiting high purity were employed, i.e. HCl, HClO4, and HNO3 from Merck as “suprapur” quality. Acid washed glassware, analytical grade regents and double distilled deionised water were used in the sample analysis. The resulting solutions were stored at 4 °C until AAS analysis.


0

150m

MEDITER

MAURITANIA

EL ABED

C O AR M

150m

N RANEA

O C

TUNISIA

0

ALGERIA

MALI

LIBYE

1606

NIGER 0

200km

Fig. 1 Map of the studied area showing the Ghazaouet area (stations A and B) and the Beni-saf area (stations C and D) where samples were collected.

All the samples were individually analysed by atomic absorption spectrophotometer AAS (PERKIN ELMER 5,000 NORWALK) and standard solutions were prepared in their specific batch solutions to avoid analytical deviation. The potential contamination of samples was evaluated analysing one acid blank in every batch.

All data were computed on a milligram per kilogram dry weight basis. The accuracy of the analytical procedures for total metal determinations was checked using PACS-1 and TORT-1 (certified standards) provided by the National Research Council of Canada. The later was analysed under the same experimental conditions. The results are shown in Table 1.

Trace Metals in Sediments, Macroalgae and Benthic Species from the Western Part of Algerian Coast Table 1 Analysis of certified reference materials: certified values and found values (mean ± S.D.) and detection limit (DL). Metals Pb Sediment Cu PACS-1 Zn Cd Pb Living Cu matter TORT-1 Zn Cd Pb Detection Cu limits (μg·kg-1) Zn Cd

Certified (mg·kg-1) 404 ± 20 452 ± 16 824 ± 22 2.38 ± 0.20 10.4 ± 2.0 439 ± 22 177 ± 11 26.3 ± 2.1 20 2.5 0.2 2

Obtained (mg·kg-1) 372 ± 9 420 ± 20 780 ± 20 2.29 ± 0.10 9.1 ± 0.6 432 ± 20 173 ± 10 26.4 ± 0.5

2.4 Geo-Accumulation Index (Igeo) Geo-accumulation index (Igeo) was introduced by Muller et al. [14] and allows the contamination of the investigated sediment with organic and inorganic pollutants to be determined by comparing present concentrations with pre-industrial levels. Concentrations of geochemical background are multiplied each time by 1.5 in order to allow content fluctuations of a given substance in the environment as well as very small anthropogenic influences. Values of geoaccumulation index can be defined as follows: Igeo = log2 (Cn/(1.5 × Bn) where Cn is the measured concentration of the heavy metal (n) in the examined bottom sediment and Bn is the geochemical background value in average shale [15] of element n; 1.5 is the background matrix correction factor due to lithogenic effects. The geo-accumulation index (Igeo) scale consists of seven grades (0-6) ranging from unpolluted to highly polluted. Muller et al. [16] proposed seven grades or classes of the geoaccumulation index: Class 0 (practically uncontaminated): Igeo < 0, Class 1 (uncontaminated to moderately contaminated): 0 < Igeo < 1, Class 2 (moderately contaminated): 1< Igeo < 2, Class 3 (moderately to heavily contaminated): 2 < Igeo < 3, Class 4 (heavily contaminated): 3 < Igeo < 4,

1607

Class 5 (heavily to extremely contaminated): 4 < Igeo < 5, Class 6 (extremely contaminated): 5 < Igeo. Class 6 is an open class and comprises all values of the index higher than Class 5. 2.5 Statistical Methods Mean metal concentrations were calculated together with standard deviations. The existence of significant differences between metal concentrations in different sites and species was tested with non parametric Kruskal-Wallis (K-W) test and the Dunn test (joint ranking test) for post hoc pairwise comparisons. A significance level of a minimum of 5% was considered in all statistical analyses. To identify differences in metals concentration between stations and species, we performed principal component analysis (PCA) on the mean of the metal concentrations in the sediments and biota (algae, limpet and sea urchin). Statistics were performed with Xlstat 2007.

3. Results and Discussion The metal concentrations in the sediment are shown in Table 2. Metal concentrations decrease in the following order: Zn > Pb > Cu > Cd. For sediments, the concentration of Zn and Cu were significantly higher (p < 0.05) in the Ghazaouet area (station A and B) than in the Beni-Saf area (p < 0.05). For Cd, significant difference was observed only between station B and station D. The important quantities of Zn in Ghazaouet area are explained by industrial releases wastes of Metanof factory dealing with the minerals zinc to extract zinc metal, cadmium, copper and sulfuric acid. The element that shows the highest Igeo values was Cd (Table 2). At all the stations, the Igeo for Cd varies between 1.78 and 6.94 allocating it in the Igeo classes 3-6 corresponding to moderately to extremely contaminated sediments. The station D in Beni-Saf has the highest Igeo index. The Igeo index for Zn, Cu and Pb were < 1 indicating moderately contaminated sediments. The metal accumulation in

1608


Table 2 Average concentration (± S.D.) (mg·kg-1 dry weight) of Cd, Cu, Zn and Pb, in the sediments with Igeo index values, green algae (Enteromorpha linza), red algae (Corallina officinalis), sea urchin (Paracentrotus lividus) and limpet (Patella ferruginea) at the four stations (A, B, C and D). Station

Sediments

Igeo index values

Cd

Cu

Zn

Pb

Cd Igeo

Cu Igeo

Zn Igeo

Pb Igeo

A

2.09 ± 2.42

46.54 ± 33.47

205.30 ± 208.83

45.22 ± 25.03

4.19

0.66

0.79

0.53

B

0.89 ± 0.58

30.77 ± 19.31

226.13 ± 212.61

31.21 ± 29.07

1.78

0.44

0.87

0.36

C

1.97 ± 2.35

16.96 ± 26.14

55.69 ± 35.03

29.86 ± 14.57

3.93

0.24

0.21

0.35

D

3.46 ± 4.21

8.14 ± 4.14

52.08 ± 21.96

28.73 ± 13.77

6.94

0.11

0.20

0.33

Station

Enteromorpha linza Cd

Cu

Corallina officinalis

Zn

Pb

Cd

Cu

Zn

Pb

A

0.36 ± 0.35

2.41 ± 2.32

29.50 ± 13.07

19.37 ± 4.94

0.641 ± 0.340

1.572 ± 0.440

18.36 ± 3.50

89.89 ± 4.70

B

0.29 ± 0.21

3.00 ± 2.51

31.96 ± 7.24

22.07 ± 7.01

0.651 ± 0.330

1.337 ± 0.680

14.97 ± 4.47

87.37 ± 4.93

C

1.92 ± 1.05

10.90 ± 7.92

34.33 ± 0.71

28.25 ± 16.88

2.103 ± 1.140

10.923 ± 8.870

41.63 ± 30.51

25.14 ± 15.20

D

1.33 ± 0.84

9.75 ± 8.39

29.68 ± 1.16

22.96 ± 19.18

2.378 ± 0.840

8.686 ± 6.640

42.76 ± 12.45

21.78 ± 10.75

Station

Paracentrotus lividus Zn

Patella ferruginea

Cd

Cu

Pb

Cd

Cu

Zn

Pb

A

0.37 ± 0.41

0.42 ± 0.42

9.36 ± 4.61

40.46 ± 12.12

0.88 ± 0.26

4.25 ± 4.54

28.40 ± 14.12

4.28 ± 1.88

B

0.36 ± 0.29

0.08 ± 0.07

7.26 ± 2.63

33.06 ± 8.22

1.52 ± 1.04

5.79 ± 3.80

48.86 ± 29.81

7.74 ± 2.14

C

0.10 ± 0.18

0.33 ± 0.35

3.15 ± 2.18

35.36 ± 6.36

0.36 ± 1.16

0.41 ± 0.41

8.24 ± 14.09 6.58 ± 8.43

D

0.25 ± 0.33

0.017 ± 0.14

8.21 ± 3.17

37.79 ± 16.26

0.05 ± 0.03

0.066 ± 0.070

2.86 ± 3.67

sediments is related to different parameters, such as sediments characteristics, particle size and organic carbon content. The determination of metal concentrations in sediment provides information about the total content but not on the bioavailable fraction. This is why we have used biological species to evaluate the marine environment quality. For the biota, significant differences were observed for algae between the two areas but not between stations from the same area. Concentrations in Cd, Cu and Zn in the red algae (Corallina officinalis) were significantly higher in Beni-Saf area whereas Pb concentrations were higher in Ghazaouet area (Table 2). A similar trend was noticed in the green algae (Enteromorpha linza) but only Cd and Cu showed significant higher concentration in Beni-Saf area. In both mollusc limpet (Patella ferruginea) and sea urchin (Paracentrotus lividus) metal concentrations were generally significantly higher in Ghazaouet area (station A and B) than in Beni-Saf area (p < 0.05) (Table 2). In E. linza and P. ferruginea metal concentrations decrease in the following order: Zn > Pb > Cu > Cd

7.76 ± 4.65

while in C. officinalis and P. lividus the sequence is Pb > Zn > Cu > Cd. In this study, metal concentrations recorded in sediments and biota were in the order of magnitude of those reported for relatively contaminated areas in the Mediterranean sea [6, 7, 10]. However, in benthic macrophytes, Zn levels not exceeding 100 mg·kg-1 were suggested as background for no polluted areas [17] and Cu levels of 200-300 mg·kg-1 have been recorded in species from polluted areas [18]. The degree of accumulation depends not only on the human activities but also on the geology and the dynamic current regime of the littoral of the Mediterranean Sea. In this study, the mean concentrations of Zn and Cu in algae varied from 29.5 to 42.7 and 2.4 to 10.9 mg·kg-1 dry weights, respectively. PCA was applied using as variables the mean of the metal concentrations in the sediments and biota (algae, limpet and sea urchin), in order to verify possible bioaccumulation patterns in species and to detect possible different contamination levels among sites in the area of study. PCA indicated that both species and stations explained significantly 87.8% of the total


variance (65.6% for factor 1 and 22.1% for factor 2) of the metal concentration (Fig. 2). Stations A and B (Ghazaouet area) were separated from station C and D (Beni-Saf area). The PCA also indicated that metal concentrations in both sea urchin and limpet were more correlated with sediments metal concentrations. These herbivorous organisms take up metals from all environmental compartments, either from the aqueous medium or through ingestion from food and inorganic particulate material. It can be supposed that metal levels in their soft tissues are substantially influenced by metals accumulated in the algae on which they graze [10]. On the contrary, macroalgae (seaweeds) accumulate trace metals from the dissolved ionic phase in seawater, reflecting the soluble trace metal content of their ambient surroundings with a high degree of time integration [19]. The close relationship between sea urchin and limpet and sedimentary environment may presume the existence of a significant relationship between the concentrations of metals in tissue of these animals and those of the sediments. The same has been suggested for the deposit

1609

feeding holothurian (Holothuria polii) [10]. Sea urchin and limpet are extensively used in monitoring programs in the marine environment due to their ability to accumulate heavy metals [6, 20, 21] and because they are among the commonest inhabitants of rocky shores in the whole Mediterranean basin [21]. For example, along the coast of Algeria, P. lividus is a dominant species of shallow-water ecosystems and up to 25 animals can be found per square metre [22]. These species can be considered as useful bioindicators of contamination. The mean metal concentrations in the different species are shown in Fig. 3. The results pointed out a high variability of metal concentrations among the species. The concentrations were significantly higher (p < 0.05) in algae compared to limpet and sea urchin. For Pb, Cd and Cu, the concentration was significantly different between the four organisms and the highest concentration for Pb and Cd were recorded in C. officinalis and for Cu in E. linza. For Zn, the concentrations were not different between the green (E. linza) and the red algae (C. officinalis). Metal levels

Biplot (axes F1 and F2 : 87.79 %) 20 15

F2 (22.16 % )

10

A

5 0 -5

B

SedPb Par Pb Par Zn Par Cu Par Cd SedCu Cor Pb Sed Zn Pat Cu Pat Cd Pat Zn

SedCd Cor Zn D Cor Cd Ent Cd Ent Cu Cor Cu Ent Pb Ent Zn Pat pb

C

-10 -15 -20 -25

-20

-15

-10

-5

0

5

10

15

20

25

30

F1 (65.63 %)

Fig. 2 Biplots for the first and second axis of the PCA based on mean values of metal concentrations (Pb, Cd, Cu, Zn) in the sediments and biota (algae, limpet and sea urchin): Sed: sediment; Ent: green algae (Enteromorpha linza); Cor: red algae (Corallina officinalis); Pat: mollusc limpet (Patella ferruginea) and Par: sea urchin (Paracentrotus lividus).

1610

Trace Metals in Sediments, Macroalgae and Benthic Species from the Western Part of Algerian Coast 100

16 12

60

Cu (mg.kg-1)

Pb (mg.kg-1)

80

40 20 0

8 4 0

1

2

3

4

1

2

species

3

4

3

4

species

60

4

50 Cd (mg.kg-1 )

Zn (mg.kg-1)

3 40 30 20

2 1

10 0

0 1

2

3

4

species

1

2 species

Fig. 3 Average concentration (± S.D.) (mg·kg-1 dry weight) of Pb, Cu, Zn and Cd in the different species: 1: green algae (Enteromorpha linza); 2: red algae (Corallina officinalis); 3: mollusc limpet (Patella ferruginea); and 4: sea urchin (Paracentrotus lividus).

are dependent on both biotic parameters and structural differences among species. Furthermore, different species of seaweed can have different affinities for different heavy metals, which may reflect competition between metals for binding or uptake sites in seaweed. Algae, in general, accumulate Zn and Cu readily from seawater [10, 23] as observed in the present study. The mean concentrations of Zn and Cu varied from 12.9 to 48 and 3.7 to 29 mg·kg-1 dry weights, respectively. In an experiment on the kinetics of metal accumulation in Enteromorpha, Seeliger et al. [24] found a linear relationship between concentrations of Cd, Cu, Pb and Zn in solution and in the algae, and concluded that it was possible to extrapolate the metal contents in the Enteromorpha tissue in order to evaluate the concentrations of dissolved metals in the water. A similar situation was found in a study by Seeliger et al. [25] in which they found good correlations between dissolved and particulate Cu and Pb levels in water and those in Enteromorpha linza and other seaweeds.

Another advantage of Enteromorpha is its resistance to high levels of contamination [26, 27]. The comparison of our data with literature indicates that, except for Pb, the concentrations of metal recorded in sediments were generally in the same order or lower than those recorded in others coastal areas. This is also the case for metals measured in the biota [6, 10, 28, 29]. When we compare the concentration of metal recorded in the present study in sediments with those from Algiers Beach (a highly polluted area along the Algerian coast) [7], it appears that for Zn and Cu the concentrations are in the same order, but for Cd and Pb concentrations are higher in our study area. For the green and red algae, metal concentrations were of the same order or lower than those recorded in those algae species from others coastal areas [10, 28-30]. Although Pb concentrations were high, these values were lower than those reported in literature (100-1000 µg·g-1) for the green algae from polluted


areas [30, 31]. For limpet, the measured concentrations of Cu, Zn and Pb were higher than those recorded in Patella caerulea from an uncontaminated area [6] but lower than those recorded in a contaminated area in the Mediterranean (Sicily, Italy) [32]. For P. lividus the concentration of Cu and Zn are lower compared with those recorded in Algiers Beach [7] but the concentrations of Cd and Pb were higher in our study.

4. Conclusion This investigation was concerned with a detailed analysis of the concentrations on Pb, Cu, Zn, and Cd in sediments, algae, sea urchin and limpet in Northern Algerian coast. Metal concentrations measured in sediments and biota indicate that the area of Ghazaouet was the most polluted. We found high variability of metal bioaccumulation among the four species analysed. The highest concentrations were recorded in the algae whereas metal concentration in sea urchin and limpet were more correlated with sediments metal concentrations. The results highlighted the difficulties associated with the utilization of different species for biomonitoring, since different species accumulate metals at differing levels. The possible existence of any regulatory mechanism within tissues, as well as of metal interactions as a consequence of exposure to known environmental concentrations, must be carefully evaluated in order to assess the usefulness of biological species as trace metal monitors.

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

References [1]

[2]

[3]

[4]

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stress, American Fisheries Society Bethesda, Maryland, 2002, p. 621. R. Amara, T. Meziane, C. Gilliers, G. Hermel, P. Laffargue, Growth and condition indices in juvenile sole Solea solea measured to assess the quality of essential fish habitat, Marine Ecology Progress Series 351 (2007) 201-208. L. Campanella, M.E. Conti, F. Cubadda, C. Sucapane, Trace metals in seagrass, algae and molluscs from an uncontaminated area in the Mediterranean, Environmental Pollution 111 (2001) 117-126. D. Soualili, P. Dubois, P. Gossellin, P. Pernet, M. Guillou, Assessment of seawater pollution by heavy metals in the neighbourhood of Algiers: Use of the sea urchin, Paracentrotus lividus, as a bioindicator, ICES Journal of Marine Science 65 (2007) 1-14. F. Henry, R. Amara, L. Courcot, D. Lacouture, M.L. Bertho, Heavy metals in four fish species from the French coast of the Eastern English Channel and Southern Bight of the North Sea, Environment International 30 (2004) 675- 683. A. Ugolini, F. Borghini, P. Calosi, M. Bazzicalupo, G. Chelazzi, S. Focardi, Mediterranean Talitrus saltator (Crustacea. Amphipoda) as a biomonitor of heavy metals contamination, Marine Pollution Bulletin 48 (2003) 526-532. M.M. Storelli, A. Storelli, G.O. Marcotrigiano, Heavy metals in the aquatic environment of the Southern Adriatic Sea, Italy, Macroalgae, sediments and benthic species, Environment International 26 (2001) 505-509. H. Agemian, A.S. Chau, An atomic absorption method for determination of 20 elements in lake sediments after acid digestion, Analytica Chemica Acta 80 (1975) 61-66. D. Feng, C. Aldrich, Adsorption of heavy metals by biomaterials derived from the marine alga ecklonia maxima, Hydrometallurgy 73 (2004) 1-10. C.T. Johansson, Digestion methods for the determination of the total contents of heavy metals, Manual of methods in aquatic environments, Research F.A.O. Fisheries Technical (1975) 131-200. G. Muller, Index of geoaccumulation in sediments of the Rhine River, Geological Journal 2 (1969) 109-118. K.K. Turekian, K.H. Wedepohl, Distribution of the elements in some major units of the earth’s crust, Geological Society of America 72 (1961) 175-192. G. Muller, Heavy metal loads of the sediments of Neckar River and its affluent, Chemical Journal 105 (1981) 157-164. J.V. Moore, S. Ramamurti, Heavy metals in near bottom water, Moscow, 1987, p. 285. (in Russian) A. Haug, S. Melson, S. Omang, Estimation of heavy metal pollution in two norwegian fjord areas by analysis of the

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Trace Metals in Sediments, Macroalgae and Benthic Species from the Western Part of Algerian Coast brown algae Ascophyllum nodosum, Environmental Pollution 7 (1974) 179-192. M.T. Brown, M.H. Depledge, Determinants of trace metal concentrations in marine organisms, in: W.J. Langston, M.J. Bebianno (Eds.), Metal Metabolism in Aquatic Environments, Chapman and Hall, London, 1998, pp. 185-217. A.H. Bu-Olayan, B.V. Thomas, Heavy metal accumulation in the gastropod, Cerithium scabridum L. from the Kuwait Coast, Environmental Monitoring Assess. 102 (2001) 187-195. M.M. Storelli, G.O. Marcotrigiano, Bioindicator organisms: Heavy metal pollution evaluation in the Ionian Sea (Mediterranean Sea-Italy), Environmental Monitoring and Assessment 102 (2005) 159-166. R. Semroud, A contribution to the knowledge of the ecosystem to Posidonia oceanica (L) of the Algiers region (Algeria): Study of a few compartments, Ph.D. Thesis, USTHB Algiers, 1993. Y.B. Ho, Metal levels in three intertidal macro algae in Hong Kong waters, Aquatic Botany 29 (1988) 367-372. U. Seeliger, M. Wallner, Multispecies metal monitoring in tropical Brazilian estuaries, in: U. Seeliger, L.D. Lacerda, S.R. Patchineelam (Eds.), Metals in Coastal Environments of Latin America, 1st ed. Springer-Verlag, 1988, pp. 258-269. U. Seeliger, P. Edwards, Correlation coefficients and concentration factors of copper and lead in seawater and

benthic algae, Marine Pollution Bulletin 8 (1977) 16-19. [26] J.C. Castilla, Copper mine tailing disposal in Northern Chile rocky shores: Enteromorpha compressa (Chlorophyta) as a sentinel species, Environmental Monitoring and Assessment 40 (1996) 171-184. [27] A.D. Marsden, W.E. DeWreede, Marine macroalgal community structure metal content and reproductive function near an acid mine drainage outflow, Environmental Pollution 110 (2000) 431-440. [28] T. Sawidis, M.T. Brown, G. Zachariadis, I. Sratis, Trace metal concentrations in marine macroalgae from different biotopes in the Aegean Sea, Environment International 27 (2001) 43-47. [29] S. Topcuoglu, C. Kirbasoglu, Y.Z. Yilmaz, Heavy metal levels in biota and sediments in the northern coast of the Marmara sea, Environment Monitoring Assessment 96 (2004) 183-189. [30] R. Zbikowski, P. Szefer, A. Latala, Distribution and relationships selected chemical elements in green alga Enteromorpha sp from the southern Baltic, Environmental Pollution 143 (2006) 435-448. [31] C. Burdon-Jones, G.R.W. Denton, G.B. Jones, K.A. McPhic, Metal in marine organisms: Part I. Baseline survey, Progress Report to the Water Qual. Council. Dept. Local Govt., Queensland, 1975, p. 105. [32] M. Contia, M.G. Finoia, Metals in molluscs and algae: A north-south Tyrrhenian Sea baseline, Journal of Hazardous Materials 181 (2010) 388-392.

D


DAVID

PUBLISHING

A Simple Bioassay Using Fluorescent Microbeads and Daphnia magna M. Kamaya, M. Sonamoto, K. Nagashima and E.N. Ginatullina Department of Environmental and Energy Chemistry, Faculty of Engineering, Kogakuin University, Hachioji-City 192-0015, Japan Received: May 6, 2011 / Accepted: June 14, 2011 / Published: December 20, 2011. Abstract: The amount of microbeads ingested by Daphnia magna decreases on exposure to toxic materials; this behavior was used to develop a toxicity test. To determine the toxicity of seven metals, D. magna were collected and homogenized, and the fluorescence intensity of the microbeads ingested by D. magna was measured. The amount of ingestion was determined from fluorescence intensity. The fluorescence intensity was half of that of the controls which was measured as the 30 min-FI50, and these data correlated well with those from an acute immobilization method (24 h-EC50). An advantage of the method using fluorescent beads is that an estimate of the 24 h-EC50 can be obtained. Key words: Bioassay, Daphnia magna, ingestion of fluorescent microbeads, metal ions.

1. Introduction Bioassays using organisms are often employed to survey the effects of chemical substances on ecological systems. Because of its ease of culture, Daphnia magna is widely used as a bioassay organism, and standardized methods have been adopted for its use [1]. These methods include the observation of rates of motion [2], heart rate [3], and food ingestion [4-7]. However, these methods have certain drawbacks such as dependence on visual inspection, requirement of analytical systems for measuring the quantity of motion, data acquisition using fluorescence microscopy, lengthy testing periods, expensive equipment, and the difficulty in obtaining accurate toxicity data because of the irradiation stress incurred during D. magna observation. We previously evaluated toxicity by observing the inhibition of chlorella ingestion [8, 9] in the presence of both chlorella and toxic substances. However, the adsorption of toxic substances onto chlorella was not considered in this method. These methods were Corresponding author: M. Kamaya, associate professor, Ph.D., main research field: simple and sensitive determination of surfactants. E-mail: [email protected].

inadequate for determining the differences between test solutions. Therefore, a more sensitive method was required. We attempted to pre-concentrate samples using the flotation method [10]. We improved the sensitivity to ingested materials by modifying chlorella and yeast using fluorescent substances [11]. However, heavy metal ions alone adsorb onto these substances. In addition, the adsorption of metal ions and co-occurrence of chlorella and heavy metal ions led to higher toxicity than that because of heavy metal ions alone [12]. The same phenomenon was reported in the case of clay [13]. Therefore, we concluded that it is undesirable to perform an ingestion test in the presence of both particulate materials and toxic components. Hence, a two-stage exposure is required for D. magna. In the first stage, D. magna is exposed to toxic substances, and in the second stage, the organisms are allowed to ingest some material. In this study, we selected fluorescent microbeads as the ingestible material for D. magna because they are non-toxic and have micrometer diameters and uniform sizes. Possible mechanisms regarding food ingestion by D. magna have been proposed. Previously, the commonly accepted mechanism was

1614

A Simple Bioassay Using Fluorescent Microbeads and Daphnia magna

apart [14]. However, because 0.2 µm particles were

contained 2.0 × 10-3 mol/L calcium chloride, 5.0 × 10-4 mol/L manganese sulfate, 7.7 × 10-4 mol/L sodium bicarbonate, and 7.7 × 10-5 mol/L potassium chloride.

retained on the filtration combs, electrostatic action

The stock solution of metallic salts was prepared

was a likely additional factor in the filtration

using the aforementioned dilution solution. The metals

mechanism [15]. DeMott [16] proposed a positive

tested were of analytical grade. The stock solution of

ingestion theory. Although copepods showed the

fluorescent microbeads (2% FluoSphere carboxylate

strongest responses to flavor treatment, Daphnia

modified microsphere (F8805); Molecular Probes Co.,

organisms did not respond. Cladocerans such as D.

Ltd., Eugene, OR, USA) contained 4.55 × 1012

magna have often been referred to as “filtration

particles/mL. The fluorescent microbeads stock

feeders”, but this designation was refuted by the use of

solution was diluted with the dilution solution to 1.37 ×

microscopy with high-speed video imaging of the

1010 particles/mL. D. magna were homogenized

feeding mechanisms [17]. The report described the

(Homogenizer-223A, Azuwan Co., Ltd., Osaka, Japan)

mechanism as follows. Overall, the body of D. magna

in a 1.5-mL micro test tube. A possible error could be

is a millimeter-scale pump that is capable of efficiently

introduced because a small amount of the solution

capturing particles from water. This is accomplished by

could be transferred along with D. magna when the

a coordinated motion of five pairs of trunk limbs (TLs)

cells were dispensed with a pipette. To minimize

inside the carapace housing. Ambient water is sucked

solution transfer, a fluororesin fiber sheet (pore

from the anterior half of the carapace opening; it flows

diameter, 70 µm) was used as described by Konig et al

for approximately 300-400 ms inside the carapace until

[18]. In the present study, a 42-mesh stainless steel net

it is discharged from the posterior half. Water flows not

was used for the transfer and washing of D. magna.

through the gap of the so-called “filter screens” of TL3

Fluorescence

intensity

and 4 but through the opening between the neighboring

fluorescence

spectrophotometer

TLs and internal surface of the carapace. Food particles

High-Technologies Co., Ltd., Tokyo, Japan).

from water are efficiently separated from the flow.

2.2 Standard Test Procedure for Toxicity Evaluation

based on filtration, in which the organisms ingest food by filtration through the filtration combs, spaced 1 µm

was

measured (F-3010,

using

a

Hitachi

Some directly reach the food groove and remain there, others stick to the finger or wing-like surface of the TLs, thereafter being brushed down to the food groove by the motion of a spire-like structure of the exposed of TL2. In the food groove, which is pushed by the brush-like structure of the endite of TL2, the particles are conveyed toward the mandibles.

2. Methods and Data 2.1 Materials D. magna was cultured in an incubator (MIR-253, Sanyo Electric Co., Ltd., Osaka, Japan) at 20 °C using spring water (present near Kogakuin University) and fed spirulina powder. The dilution solution was as described in the JIS K 0229 [1] test method and

The metallic test solutions were diluted to five different concentrations with the dilution solution. Test solution aliquots of 10 mL were dispensed into glass containers, and 10 neonate individuals (aged < 24 hours) were transferred to each of the containers and exposed to the solution for 30 min. Next, the neonates were transferred to containers with 10 mL of fluorescent microbeads for 5 min to allow ingestion. These D. magna were then filtered using the stainless steel net, washed with water, transferred into a micro test tube containing 0.5 mL of water, and homogenized for 2 min. After homogenization, 1.0 mL of water was added to the solution, and the fluorescence intensity was measured using an excitation wavelength of 356 nm and a fluorescence wavelength of 413 nm.


3. Results

1615

1.5 1

log[(F0－Fn)/Fn]

We attempted to evaluate the toxicity of seven metals by assessing the decrease in the intake of fluorescent microbeads by D. magna. Toxicity was measured by the fluorescence intensity of the ingested beads after 30 min exposure to varying concentrations of test solutions. The ingestion period was observed using a fluorescence microscope, and it was found that the microbeads were excreted after 5 min. The results of the toxicity test using potassium dichromate are shown in Fig. 1.

y = 1.5445x - 1.0234 R 2 = 0.943

0.5 0 0

0.2

0.4

0.6

0.8

1

1.2

-0.5 -1 -1.5

Log[K2Cr2O7] (mg/L)

with log[K2Cr2O7] and log[(F0－Fn)/Fn], where F0 and

Fig. 2 Relationship of log [K2Cr2O7] and log[(F0－Fn)/Fn]. F0 and Fn are the fluorescence intensities of the control and individual concentrations of K2Cr2O7, respectively.

Fc were the fluorescence intensities of the control and

Table 1 Estimation of 30 min-FI50 and 24 h-EC50.

To calculate the 30 min-FI50, a graph was plotted

individual concentrations of potassium dichromate, respectively. The result obtained by this treatment is shown in Fig. 2. From Fig. 2, the equation of log[(F0－Fn)/Fn] = a log(K2Cr2O7) + b was obtained. From this equation, the y axis = 0, i.e., log[(F0－Fn)/Fn] = 0, this indicates FI-50, i.e., half of the fluorescence intensity of F0. The 30 min-FI50 for potassium dichromate was 5.6 mg/L, and 30 min-FI50 values for other metals are presented in Table 1. The same metals were tested by standard methods for determining the inhibition of the mobility of D. magna (24 h-EC50), and these results

Cr(IV) Ag+ Mn2+ Co2+ Ni2+ Zn2+ Hg2+

The correlation of these data is shown in Fig. 3. A correlation coefficient of 0.9938 (R2) was obtained for the 30 min-FI50 and 24 h-EC50 data. This high correlation facilitates the evaluation of 24h-EC50 by the proposed method.

160

45

140

40

120

35

100

30

80

24h-EC50

Fluorescence Intensity

are also shown in Table 1.

60

Concentration (mg/L) 30 min-FI50 24 h-EC50 4.11 0.77 1.57 × 10-3 0.883 × 10-3 357.2 42.76 96.70 12.02 44.6 15.34 28.64 1.00 3.18 × 10-2 0.81 × 10-2

Metals

y = 0.1212x - 0.9696 2 R = 0.9938

25 20

40

15

20

10 5

0 0

10

20

30

0 0

K2Cr2O7 (mg/L) Fig. 1 Relationship between the concentration of K2Cr2O7 and fluorescence intensity.

50

100

150

200

250

300

350

-5 FI-50

Fig. 3 Relationship of 30 min-FI50 and 24 h-EC50.

400


1616

4. Conclusion D. magna becomes weaker on exposure to toxic solutions. In this study, the degree of weakness was evaluated based on the degree of ingestion of materials. Fluorescent microbeads were used because of their bright fluorescence, size uniformity, small diameter (0.2 µm can be obtained), and good solution stability. The optimum time for the ingestion of this material was 5 min, and the procedure was performed after 30 min of exposure to test solutions. The evaluation of toxicity was performed by measuring the fluorescence intensity (FI50) of the ingested beads that was half that of the control. The proposed toxicity test was applied to solutions of seven heavy metals, and the FI50 values obtained after 30 min of exposure were compared to those from an acute immobilization test (24 h-EC50). The 30 min-FI50 and 24 h-EC50 data showed positive correlation; the correlation coefficient was 0.9938. The proposed test is very useful for the estimation of the 24 h-EC50 of chemicals and can be applied to the sample containing unstable substances such as volatile or biodegradable organic matter. At a test duration of 30 min-FI50, D. magna were not killed. If the time of exposure is increased, the proposed method may be applicable for the Daphnia reproduction test or the whole effluent toxicity test.

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[14]

References [1]

[2]

[3]

[4]

JIS (Japanese Industrial Standard), No. K 0229/1992 on testing methods for determination of mobility of Daphnia by chemicals, 1992, p. 45. I. Aoyama, R. Ruo, H. Okamura, Monitoring of the hazardous chemical substances by the momentum analysis of Daphnia magna, Kankyo Gijutu 26 (1997) 255-259. M. Presing, M. Vero, A new method for determining the heart beat rate of Daphnia magna, Water Resources 17 (1983) 1245-1248. S. Lee, N. Eun-Jung, C. Young-Ok, B. Koopman, B. Bitton, Short-term toxicity test based on algal uptake by ceriodaphnia dubia, Water Environment Research 69 (1997) 1207-1210.

[15]

[16] [17]

[18]

G. Bitton, K. Rhodes, B. Koopman, M. Cornejo, Short-term toxicity assay based on daphnid feeding behavior, Water Environment Research 69 (1997) 1207-1210. G. Bitton, K. Rhodes, B. Koopman, An acute toxicity test based on Ceriodaphnia dubia feeding behavior, Journal of Environment Toxicology Chemistry 15 (1996) 123-125. C.M. Juchelka, T.W. Snell, Rapid toxicity assessment using ingestion rate of cladocerans and ciliates, Archives of Environmental Contamination and Toxicology 28 (1995) 508-512. M. Kamaya, J. Tanabe, K. Nagashima, Toxic assessment by feeding rate of Daphnia magna, Yousui to Haisui 43 (2001) 116-120. M. Kamaya, M. Yokota, K. Nagashima, A rapid toxicity test based in inhibition of feeding rate with Daphnia magna, Yousui to Haisui 46 (2004) 943-947. M. Kamaya, Development of toxicity evaluation method with Daphnia magna using air stripping concentration, Yousui to Haisui 46 (2004) 173-178. M. Kamaya, K. Ikemoto, K. Nagashima, Quick evaluation of toxicity utilizing measurement of ingested fluorescent materials by Daphnia magna, Yousui to Haisui 48 (2006) 176-180. G. Taylor, D.J. Baird, A.M.V.M. Soares, Surface binding of contaminants by algae: Consequences for lethal toxicity and feeding to Daphnia magna Straus, Environment Toxicology Chemistry 17 (1998) 412-419. R. Weltens, R. Goossens, S.V. Puyymbroeck, Ecotoxicity of contaminated suspended solids for filter feeders, Archives of Environmental Contamination and Toxicology 39 (2000) 315-323. K.G. Porter, Y.S. Feig, E.F. Vetter, Morphology, flow regimes, and filtering rates of Daphnia, Ceriodaphnia, and Bosmina fed natural bacteria, Oecologia 58 (1983) 156-163. J. Gerristen, K.G. Porter, The role of surface chemistry in filter feeding by zooplankton, Science 216 (1982) 1225-1227. W.R. DeMott, The role of taste in food selection by freshwater zooplankton, Oecologia 69 (1986) 334-340. Y. Tanaka, Direct observation on zooplankton feeding mechanisms, Japan Plankton Gakkaiho 51 (2004) 151-154. P. Konig, H.G. Muller, A rapid easy method to introduce Daphnia magna into test vessels, Bulletin of Environmental Contamination and Toxicology 26 (1981) 22-23.

D


DAVID

PUBLISHING

Sedimentary Environments, Geometry and Characteristics of the Sand Layers within the Basin of El Ma Labiod (Algero-Tunisian Borders) M. Hamimed1, M. El Kadi2 and M. Al Shara2 1. Department of Geology, Faculty of Exact, Natural and Life Sciences, University of Tebessa, Tebessa 12002, Algeria 2. Department of Geology, Faculty of Sciences, University of Damascus, Damascus 12345, Syria Received: February 23, 2011 / Accepted: June 11, 2011 / Published: December 20, 2011. Abstract: The authors’ work concerns the study of sedimentary environments, the geometry and the characteristics of the silicon-clastic deposits within the basin of El Ma Labiod at the Algero-Tunisian confines. The sedimentological analysis has proved a Miocene age of the sediments with varied environments: marine, fluvial-deltaic and lake. The geological aspect of the sediment, in particular sandy, is of the movable type or very slightly consolidated. The size of the industrial sand layers can be very diverse, however to feed from the industrial consumers having a certain perenniality, our prospection was directed towards layers with very important reserves. It is about a sedimentary basin with dimensions exceeding very largely the conditions of operating for such projects, which are at least one to two million tons. With the exception of a thin quaternary soil horizon, the basin is almost of an exploitation with open sky. The mineralogical determination has revealed siliceous to extra-siliceous sands, which are absolutely usable in the industry of glass, foundry and also in other functions like the abrasives of sanding and the clothing industry of the sandpapers. Concerning the economic aspect, the materials are very close and this is why the area has known the installation of a glassmaking factory and a cement factory using at the same time the Maastrichtian limestone, the sandy material and the clays of the Western zone of the basin. Key words: Miocene, El Ma Labiod basin, sedimentary environments, mineralogy, petrography, economic aspects.

1. Introduction

sediments of the basin of El Ma Labiod were established by Durozoy [1] which had determined,

The area of study lies between 35°12'-35°20' N and 8°3'-8°20'

E.

It

corresponds

to

the

miocene

sedimentary basin of El Ma Labiod pertaining to the eastern

zone

of

the

Saharan

Atlas

at

the

Algero-Tunisian borders (Fig. 1). To draw up this study, eight profiles were taken into account from north to the south of the basin: the profile of Aioun el Ksob close to Mechta Ben Falia, the profile of Hadjer Sefra, the profile of Ain Dokkara, the profile of Bou Roumane and the profile of Tenoukla. The first known observations on the

without any paleontological evidence, within the geological map of Tebessa: a lower Miocene (Burdigalian), a middle sandy Miocene (Vindobonian), finished by a marly upper Miocene (Pontian). The determination of the sedimentary environments is based on the one hand on macroscopic observations in the

in

particular

the

petrographical

characteristics, the sedimentary structures and the tectonic phenomena, and on the other hand on work of laboratory to knowing the

grain size analyses

[2], the petrographical and paleontological purposes and

Corresponding author: M. El Kadi, professor, Ph.D., main research fields: sedimentology and subsurface geology. E-mail: [email protected].

field,

the

coefficients.

calculation

of

the

sedimentological

1618

Sedimentary Environments, Geometry and Characteristics of the Sand Layers within the Basin of El Ma Labiod (Algero-Tunisian Borders)

Fig. 1 A geological sketch of the area of El Ma Labiod (Durozoy, 1956) [1] (reinterpreted by the authors). Legend: (A)-Aioun El Ksob profile; (B)-Southern Hadjer Sefra profile; (C)-Northern Hadjer Sefra profile; (D)-Ain Dokkara profile; (E)-Sif Bou Roumane profile; (F)-Djebel Khorza profile; (G)-Bordj Tenoukla profile; (H)-Tenoukla Collar profile; 1-Quaternary (Q); 2-Pliocene (P); 3-Upper Tortonian: multi-coloured clays (M3-2); 4-Lower Tortonian (M3-1): sandstone with argillaceous intercalations; 5-Langhien-Serravalien (M2): sandstone; 6-Emscharian (C7): marls with lumachella; 7-Turonian (C6): calcareous at the base and marly at the top; 8-Cenomanian (C5-4): marly with lumachella; 9-Vraconian (C3): black marly limestone; 10-Albian (C2-1): grey limestone; 11-Aptian (CI-II): limestone at the top and dolomitic limestone at the base; 12-Geological contours; 13-Faults; 14-Dips.

2. Sedimentary Environments and Sequential Correlation of the Studied Profiles

three cycles of this profile show

In the basin of El Ma Labiod, the Miocene sediments of Langhian-Serravalian [3] are in discordance on the Cretaceous. They are in regressive matter and are developed in offlap structures towards the north and the north-west.

(B) (Fig. 2) of the southern Hadjer Sefra (thickness 90

Profile (A): In this profile (Fig. 2) of Aioun el

fourth cycle begins with the beach sediments and ends

Ksob (thickness 30 m), one notes the presence of three

in deltaic deposits with iron-siliceous cover. The

sedimentary cycles whose the first is marine

thicknesses of the cycles in this profile are more

(conglomerate with marine fauna), the second is

important than in the preceding profiles.

the

thicknesses. Profile (B): Furthermore to the NW, in the profile m), the Miocene sediments rest on the Cretaceous sediments. In this profile, one notes the absence of the sediments of cycle 1 which starts with the cycle 2 followed by the cycle 3, and the both are littoral. The

translative

Profile (C): In the profile (C) (Fig. 3) of the

third is deltaic. The

northern Hadjer Sefra (thickness 50 m), one observes

littoral (waves breaking, bed flow, waves and beach) and

rather small


1619

Fig. 2 Langhian-Serravalian: geological profiles (A) and (B). Figure captions of the Fig. 2: B-Beach; BV-Breaking of vagueness; BF-Bed of flow; D-Delta; Gl-Glauconite; Md-Median; SC-Suspension current; Th-Thickness in meters; TV-Translative vagueness; Ing-Ingression; IS-Inverse sequence; IMS-Inverse megasequence; SMS-Simple megasequence; SS-Simple sequence.

Fig. 3 Langhian-Serravalian: geological profiles (C) and (D). Figure captions of the Fig. 3: B-Beach; D-Delta; BF-Bed of flow; BV-Breaking of vagueness; DP-Delta plain; Ing.-Ingression; Md-Median; SC-Suspension current; Th-Thickness in meters; IMS-Inverse megasequence; R-River; SMS-Simple megasequence; SS-Simple sequence.

1620


two cycles (4 and 5) whose the fourth one is deltaic and the fifth, only presented by the simple megasequence, is fluvial. At the top, there is also the ferro-siliceous crust of continental weathering. Profile (D): In the profile (D) (Fig. 3) of Ain Dokkara (thickness 80 m) the Miocene sediments rest on the marls of upper Turonian. This one starts with the reverse megasequence 3, with littoral sandy deposits which pass at the summit to deltaic deposits. In this profile, the two cycles (1 and 2) and the simple megasequence 3 are absent, this proves an offlap structures development of the sediments to the northern direction. The reverse megasequence 3 is mounted by the cycle 4 with a littoral or marine base (simple megasequence 4) followed by the deltaic deposits (inverse megasequence 4). Finally, this profile is terminated by the cycle 5 (simple megasequence 5) which begins by a deltaic

sedimentation in the lower part and passes upper to fluvial sediments. At the top of this profile, one also notes the presence of the ferro-siliceous crust of continental weathering. Profile (E) and (F): In the profiles of Sif Bou Roumane (E) and Djebel Khorza (F) (Fig. 4) with respective thicknesses 160 m and 155 m, the sequential analysis shows seven sedimentary cycles [4], which are developed in offlap structures towards the west of the basin. These cycles reveal four principal continental environments of river, delta, lake and marsh. The profile is mainly characterized by deltaic and river deposits with rather weak subsidence, intercalated by two periods of Lake Mode where subsidence was felt better. The profile also shows a period when sedimentation is fully marshy proving a subsidence even weaker, it is probably the period of greater stability of the basin.

Fig. 4 Lower Tortonian: geological profiles (E) and (F). Figure captions of the Fig. 4: D-Delta; Md-Median; IMS-Inverse megasequence; IS-Inverse sequence; L-Lake; Ma-Marsh; R-River; SMS-Simple megasequence; SS-Simple sequence; Th-Thickness in meters. 1-Dishes structure sandstone; 2-Parallel structure sandstone; 3-Tilted structure sandstone; 4-Flow structure sandstone; 5-Disordered structure sandstone; 6-Argillaceous sandstone; 7-Silted clays; 8-Marls; 9-Limits of facies; 10-Angular unconformity.


Profile (G) and (H): In the profiles (G and H) of Tenoukla (Fig. 5) with respective thicknesses 330 m and 250 m, the sequential analysis reveals five elementary cycles [5] also developed by progradation

1621

towards the west. The lower part of the profile shows passages between sediments of river and delta, which pass in the upper into lake sediments and finally into those of marsh.

Fig. 5 Upper Tortonian: geological profiles (G) and (H). Figure captions of the Fig. 5: Cr-Cretaceous; D-Delta; Env-Environment; IMS-Inverse megasequence; IS-Inverse sequence; L-Lake; Ma-Marsh; Md-Median in micron meters; Mi-Miocene; N°-Sample number; R-River; SMS-Simple megasequence; SS-Simple sequence; T-Tortonian; Th-Thickness in meters.

1622


3. Petrographic Analysis

4. Geological and Economic Aspects of Studied Sands

The Miocene profile is constituted, within its lower part, of sands and very tender sandstones (of white or yellowish color) intercalated by thin argillaceous levels.

However, towards

its

higher part

the

sedimentation becomes marshy with thin gypseous intercalations. The quartz grains are well blunted and sometimes even rounded and brilliant testifying a long fluvial transport, which is also proven by the total absence of feldspars and the scarcity of the micas in the sediments. According to the classification of Czerminski (Fig. 6 and Fig. 7) [6], the petrographic analysis shows clearly the distribution of the sediments in two great sets of sandstone and tender formation. The sandstones are especially represented by two important fields of sandstone strictly speaking and argillaceous sandstone, and of some marly sandstone samples with very weak carbonate rate, which explains a detritus origin of the material. The tender sediments are also much more argillaceous than carbonated, and they are represented by clays strictly speaking, clays (marly, sandy and marly-sandy spreaders), marls strictly speaking and argillaceous marls.

Fig. 6

Classification of the Langhian-Serravalian rocks in the

basin of El Ma Labiod (according to Czerminski 1955) [6].

The studied industrial sands are absolutely movable sediments or very slightly consolidated by argillaceous cement of very low rate always (< 5%). They are of marine origin at the base, passing to fluvial, deltaic and then lake. The size of the industrial sand layers can be very diverse, however to feed the industrial consumers having a certain perenniality, our prospection was directed towards layers containing the very important reserves. The latter form an entire sedimentary basin (of an average size of 20 km of length, 7 km broad and an average thickness of 100 m for Langhian-Serravalian and 200 m for Tortonian), exceeding very largely the conditions of operating for such projects, which are at least of 1 to 2 million tons. The economic aspect of this sand layer appears of a very considerable importance. Indeed, the sand layer constitutes a large sedimentary basin in the open air, crossed in full medium by a national road and railroad. With the exception of a layer of a few centimeters forming the ground, all the thickness of the formation is exploitable, therefore, the ratio D/E (discovery on exploitable) is regarded as null.

Fig. 7

Classification of the Tortonian rocks in the basin of El Ma

Labiod (according to Czerminski 1955) [6].

Legend: 1-Clay; 2-Marly clay; 3-The argillaceous marl; 4-The marl; 5-Marly limestone; 6-Limestone; 7-Sandy clay; 8-Marlo-sandy clay; 9-Marlo-sandy limestone; 10-Sandy limestone; 11-Argillaceous sandstones; 12-Marly sandstones; 13-Carbonated sandstone; 14-Sandstone.


5. Criteria of Selection and Principal Uses In addition to the geometrical and economic criteria of the industrial sand layers mentioned above, the characters of the sands also respond to the criteria of selection of the granularity and the chemical composition of the sands. The granulometric distribution of the 97% of the sand are always retained on not more than 5 successive sieves, and the content of the particles of a size lower than 20 µ varies between 0.3 and 4% at the most, in other words the sand is in general a siliceous to exta-siliceous type [7]. The chemical composition of the sands has also showed that the latter are very siliceous and contain only negligible carbonate contents (0.0-0.3%) and some very weak traces of iron oxide towards the west of the basin, coming especially from the continental weathering at the top of the Langhian-Serravalian. It is noted that the index of smoothness is variable according to the sedimentary type of environment. In general the grains more coarse than 0.85 mm (sieve 30 in AFNOR) are very rare and represent only the bottom grades of the sandy segments, therefore a very good industrial sand for the glassmaking.

generally of an exploitation with open sky. The mineralogical determination with the binocular magnifying glass and the chemico-ponderal analysis have revealed that sands are especially siliceous to extra siliceous and are absolutely usable in industry of glass, foundry and thus in other functions like abrasives of sanding and clothes industry of the sandpapers. Concerning the economic aspect, the materials are very close and this is why the area has known the installation of a factory of glassmaking and a cement factory also using the sandy material and thus in the same way clays in the western zone of the basin.

References [1]

[2] [3]

[4]

6. Conclusion The granulometric and sedimentary analyses at the laboratory of sedimentology have proved that the material in question is of a Miocene age and is from varied environments of marine, fluvial-deltaic and lake types. The geological aspect of the sediment, in particular made of quartz, is of the movable type or very slightly consolidated by an argillaceous cement. The size of these industrial sand layers is of an immense importance (a basin in entirety) and

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[5]

[6]

[7]

G. Durozoy, Geological map of Tebessa at 1/50000, in: Geol. Map Service of Algeria (Eds.), Algiers, 1956, p. 206. G.S. Visher, Grain size distribution and depositional processus, J. Sedim. Petrol 39 (1969) 1074-1106. M. Hamimed, W.M. Kowalski, Sedimentological analysis and paleogeography of the Miocene sediments (Langhian-Serravalian) of the surroundings of Tebessa (North-East of Algeria), Bull. Geol. Serv. of Algeria 12 (2001) 49-75. M. Hamimed, W.M. Kowalski, A. Pharisat, Granulometrical and sequential analyses of the lower Tortonian of El Ma Labiod basin, in: Bull. Hist. Nat. Soc. of Montbelliard, France, 2001, pp. 249-259. M. Hamimed, S. Boulamia, A. Pharisat, W.M. Kowalski, Sedimentological and sequential analyses of the upper Tortonian of El Ma Labiod basin, in: Bull. Hist. Nat. Soc. of Montbelliard, France, 2010, pp. 241-247. J. Czerminski, Classification and Nomenclature of Sedimentary Rocks, Geol.3, (skal, Osadowych. Przegl.), Widawnictwo Geological Publisher, Warsaw, 1955. M. Delfau, Y. Berton, L. Goubès, M. Grès, P. Le Berre, A. Prax, Guide of Quarries Material Prospection, 2nd ed., BRGM Press, 1995, pp. 127-134.


D DAVID

PUBLISHING

Using Geospatial Information Systems in Analyzing Urbanization Impacts on Stream Habitats in Southern Mississippi Coastal Ecosystem E. Merem1, S. Yerramilli2, C. Richardson1, J. Wesley1, T. Walker3, D. Foster1, J. Williams1, C. Romarno1 and E. Nwagboso4 1. Department of Urban and Regional Planning, Jackson State University, Jackson, MS 39211, USA 2. National Center for Biodefense Communications, Jackson State University, Jackson, MS 39204, USA 3. Department of Epidemiology and Biostatistics, Jackson State University, Jackson, MS 39213, USA 4. Department of Political Science, Jackson State University, Jackson, MS 39217, USA Received: June 7, 2011 / Accepted: July 18, 2011 / Published: December 20, 2011. Abstract: The proliferation of urban development with concentration in population and human-environment interaction has intensified around urban environments. This has resulted in the degradation of urban environments, overuse of natural resources and widespread pollution of ecosystems. The patterns of design initiatives continue to follow unsustainable path with impacts on stream ecosystems. Accordingly, the paper adopts geospatial information systems and sustainability principles for the identification and sequential mapping of stressors impeding natural systems in Southern Mississippi. The results not only reveal that the study area experienced some significant changes in its watershed environments, but the stream habitat ecosystem remains under stress. The recommendations for mitigating the problems range from policy considerations to the adoption of ecosystem approach. Key words: Geospatial information systems, urbanization, ecological design, ecosystem approach, environmental degradation.

1. Introduction Increasing signs demonstrating clear threats to the sustainability of ecosystems supporting human societies gave rise to various theories of human-environment interactions upon which basic material conditions, such as population, development, urbanization and other elements all impact the environment [1]. Compounding these concerns, it is the pace at which widespread proliferation of urban development with subsequent concentration of population and the human-environment interaction has intensified around stream environments in the last several years especially around the southern Corresponding author: E. Merem, Ph.D., associate professor, research fields: climate change, GIS, natural resources management, environmental planning, land use, agriculture, remote sensing and watershed management. E-mail: [email protected].

Mississippi Region coastal counties [2]. Considering the scale at which growing population and the competition for limited land resources impede natural resource bases and habitats in estuarine environments of the area. The public attention has now been drawn to the un-sustainability of land use practices in coastal counties where numerous stressors unleashed from urbanization continue to ravage sensitive stream habitats [3]. Accordingly, the mounting pressure from population growth in urban areas which is occurring at an alarming proportion continues to put enormous strain on urban ecosystem and the surrounding stream habitat environments. This has resulted in the degradation of stream habitats in urban environments and over utilization of natural resources to meet the needs of built up areas. There is also widespread pollution

Using Geospatial Information Systems in Analyzing Urbanization Impacts on Stream Habitats in Southern Mississippi Coastal Ecosystem

beyond the carrying capacity of the ecosystems. In the process, the patterns of urban design initiatives continue to follow unsustainable path leading to landscape transformations with grave impacts on stream ecosystems [4]. At the same time, various development activities have been adopted at the expense of environmental welfare of communities. The factors responsible for the problems are not far fetched. They range from socio-economic variables and policy elements. This is happening at a time when most stream ecosystems are impacted by urbanization processes due to the negation of environmental design principles based on sustainability and design patterns that are in sync with nature [5]. There are also concerns about the hazardous effects of such activities as agriculture, urban and industrial development on freshwater habitats in built up areas [6, 7]. Some of the most pervasive effects embody the increase in impervious surface cover within urban catchments. Such increases not only alter the hydrology and geomorphology of streams but it leads to changes in the stream habitat corridors. Existing literature has shown how runoffs from urbanized surfaces drive the loading of nutrients, pesticides and contaminants into ecosystems with resultant decline in both fish and algae populations. The rising incidence of non point source chemical pollution also poses enormous danger to the estuarine and coastal environments such as those in the southern Mississippi region [8]. Typically, excess storm water run off wrecks major havoc in a large number of urban areas by causing water pollution, ground water recharge deficits, and ecological damage to urban streams [9]. The proliferation of impervious surface allows for rain to get to a stream faster, creating higher pick flows that can lead to a stream alteration and habitat degradation. When impervious surface stops rainfall from permeating the soil, smaller amount of water is available for groundwater recharge and this in turn minimizes stream base flow. Depending upon the land use in the watershed or

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stream corridor, roadways and parking lots nutrients that move over the surface through major storms often drain into water ways creating elevated toxic loading of the stream. In some areas, sensitive wetlands and various species are endangered because streams are overstretched by artificial run off from impervious surfaces and built up areas from urbanization [10, 11]. Similarly, in an earlier study of the little Miami River Basin, Susanna et al. [12] noted that urban development in the watershed had caused considerable change on run off and water quality. In the context of southern Mississippi, regional statistics and indicators for building and construction associated with these problems have grown exponentially over the years in affected counties. It is evident that the run off from different types of urban land use carry different kinds of contaminants. For example, run off from agricultural land use in the southern Mississippi region are enriched with nutrients and sediments. Compounding the matter is the lack of geospatial information systems and eco-design approach in current measures. Convinced about the risks, the current patterns of development pose to the environment. The World Commission on Environment and Development stressed the need to factor ecological and economic variables during decision making [13]. In the urban context, Edwin et al. [14] have noted that achieving ecosystem sustainability requires mitigation of some of these problems with the right tools. Clearly, ecosystem approach often represents the most appropriate type of model for analyzing human influences on ecological systems; it can play a central role in the design and analysis of alternative agricultural, industrial and residential systems that could reduce the human footprint on the earth [15]. Just as the ecosystem approach is a method for sustaining ecological desired future conditions that integrates ecological, economic and social factors in development. It also recognizes the importance of integrating science and technology, the economy and society’s demands in the management of resources such as urban stream

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habitats. Accordingly, there is an urgent need for the adoption of ecological design approach based on the applications of geospatial information systems for the identification and sequential mapping of urban stressors impeding the viability of natural systems in the southern Mississippi region. In light of that, the assessment of ecosystem health of stream habitats using Geographic Information Systems (GIS) to detect change not only enhances our understanding of the scale of changes occurring in these systems, but it provides a framework for evaluating ecosystem decline and the mechanisms for restoration [16-19]. In the case of GIS, Gaurav [20] developed the eco-assessor based decision support system for the lower part of the Yazoo river Basin in Mississippi to help planners and managers determine the best locations for the restoration of wetlands on defined ecological and geographic criteria and probability of success. In the study, potential restoration area assessment involved data over lays sorted by hydrology, water quality and habitat. Elsewhere Joan et al. [2] adopted GIS and remote sensing in estimating the rates of change along the Pascagoula River and its tributaries in the Southern Mississippi area. In considering how modifications generated by human activities influence the changes. The authors digitized the larger and mined tributaries of the system in a GIS using varied sources of data such as aerial photographs and other types of spatial information. In a related work, another researcher adopts remote sensing and geospatial applications in the delineation of the Upper Pearl River watershed in the State of Mississippi [21]. The idea behind the study hinged on the benefits of accurate delineation of stream habitats (watersheds) using GIS in the management of the ecosystem [21]. Current remote sensing and geographic information systems technologies as the study noted promote rapid collection of field-data and prompt processing. Notwithstanding these capabilities, in the past years, widespread level of development triggered by human

activities has been eroding the environment and support systems along major stream ecosystems in the study area. In fact, direct and indirect effects of human activities continue to ravage estuaries. In the case of Mississippi, with limited efforts to curb ecological decline facing major watersheds of the state, Southern Mississippi River watersheds most notably the Pascagoula and the Southern streams now have the appearance of a stressed ecosystem with cases of water pollution [22]. In the Gulf area of the state, developers who do not have their property zoned for business and economic development continually request changes to the land use plan. They prefer that general use district such as residential and recreational be rezoned to allow for casino developments on sensitive coastal environments. Compounding the issue is the limited effort to evaluate the cumulative and secondary effects of these developments [23]. With such pressures, river systems in the area have experienced cases of water impairment caused by fecal coliform, mercury, PCBs and other contaminants and nutrients from agricultural runoff and other types of land use. A case in point is Turkey Creek in the coastal streams running through the wetlands of the North Gulfport in the Bay of Biloxi. The Turkey creek area as the focus of growth in the past decades attracts developers seeking permits to dreg hundreds of acres of wetlands in the area. The pressures from large-scale development, however, has contributed to the impairment of water quality along the Turkey creek area of the Basin [24]. While the other indicators of change in the Pascagoula basin involve water-body declines and other variables, using spatial information systems in stream habitat management minimizes the time needed to obtain inputs on water quality models. This can increase the measurement precision of stream habitat and watershed conditions [25]. The paper focuses on the issues, theory and practice of ecosystem design by using geospatial information technologies in the study of changes in urban streams/ecosystems in cities, with emphasis on


ecological and environmental design principles in alleviating these problems. Adopting such an approach can provide planners information about the casual effects of disturbances in ecosystems and help them contribute to a more effective urban management in terms of environmental protection and through the infusion of ecological design principles in practice. The paper has five objectives. The first objective is to update the literature on ecosystem restoration, while the second objective centers on the need to identify ecological change issues along costal urban environments. The third objective is to apply spatial information technology such as GIS in gauging the pressures of urbanization along stream habitats and the fourth aim is to design decision support tools for assisting decision makers and resource mangers in monitoring environmental change. The fifth objective is to identify appropriate strategies and the efforts for curbing the threats of ecological change caused by urbanization. In terms of organization, the paper contains five sections. The first part covers the introduction of the paper while section two on methods and materials highlights the background on the study area and the methodology. The third part presents the results and the analysis on environmental change and the factors fuelling change. Section four contains a brief discussion of the results and suggestions for remedying the problems. Section five presents the conclusions.

contains major thriving urban areas prone to pollution and other environmental problems. The major river basin, the Pascagoula, is Mississippi’s second largest basin measuring approximately 164 miles long and 84 miles wide draining an area of about 9,600 miles before emptying into the Gulf of Mexico. It is also the largest unimpeded major river system in the continental United States. The major streams include the Pascagoula, Leaf and Chicksawhay Rivers as well as the Black and Red Creeks [26, 27]. The total estimated land area of the watershed measures about 386,008 acres with non-irrigated cropland and pastureland as the major land-uses. About 72% of the basin contains forested area and the other 21% classified as agricultural land. With the presence of generally well-drained and moderately drained soil types, the basin contains about 542 farms and an average farm size of 94 acres. The size of Cropland stretches across an area estimated at 22,100l acres while pastureland consists of 20,800 total acres [27].

2. Methods and Data 2.1 Study Area The study area located in southern Mississippi along the coastal plain in the southern portion of the map in Fig. 1 encompasses 6 selected counties. The six counties under analysis that consists of Pearl River, George, Stone, Harrison, Hancock and Jackson have a combined population 437,408 in 2006 (Table 1). The study location stretches through major urban areas along the Gulf coast region of Pascagoula and Biloxi-Gulfport metro areas. As shown in the table, it

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George Pearl River

Stone Jackson

Hancock

Fig. 1 The study area: southern Mississippi region.

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Table 1 The population and profile of southern Mississippi costal counties. County Pearl River George Stone Harrison Hancock Jackson Total

Population 57,099 21,828 15,608 171,875 40,421 130,577 437,408

Area in square miles 811 478 445 580 476 726 3,516

From an economic standpoint, timber use in the basin generates $325 million dollars to the economy. The Pascagoula basin accounts for 75% of oil and gas

CMA Picayune Pascagoula Gulfport-Biloxi Gulfport-Biloxi Gulfport-Biloxi Pascagoula NA

geospatial information systems. 2.2 Methods

Pascagoula, Moss Point, Meridian, Hattiesburg and

This paper stresses a mix scale approach involving the use of descriptive statistics, correlation analysis and geospatial technologies of Geographic Information Systems (GIS) in processing data provided through government sources and data bases from other organizations. The raw spatial data made up of maps and other kinds of digital information used in the research came from the United States Geological Surveys (USGS) data procurement unit, USDA and US EPA, the Government of Mississippi MARIS and United States Census and other organizations such as the University of Maryland On line data unit.

Laurel [2, 28].

2.3 Step 1: Data Acquisition

production in the state and there are about 250 surface mining operations in the area [28]. While agricultural and timber activities declined in the region in recent years, other forms of land use have increased their impact on the ecosystem. Although in channel mining was quite rampant in the area until it was banned in 1995. Floodplain sand and gravel mining remain active on the Bowie River side of the basin as well as in Thompson creek and Leaf River. At the same time, simultaneous development has been occurring in many parts of the basin, including the cities of

Some of the threats in the area that require conservation

efforts

anchored

in

sustainability

principles are the threats of sediments entering streams and rivers in the Pascagoula as well as the issue of in-stream sedimentation caused by scouring of bed and bank erosion. The scale of unsustainable silver culture practices and unparalleled road construction for development in the area creates sedimentation concerns as well as interruption of hydrologic flow along the stream habitats. This has been compounded by gravel mining sedimentation and the alterations to hydrologic regimes threatening the migration and the spawning habitats of the Gulf Sturgeon, Pearl Darter and Alabama Shad [29]. The extent of these changes and the ecological impacts caused by development activities in the basin can be properly assessed using

The first step involves the identification of the variables needed to assess the environmental impacts of urbanization on stream habitats in urban areas at the regional level. The spatial units of analysis consisted of the counties located in the Gulf region (Table 2). The variables encompasses socio-economic and environmental data, including land cover elements (of the amount of farmland, fertilized areas, impaired water bodies), population, number of building permits and the monetary values of construction and sales from agriculture. This process continued with the design of data matrices covering the various periods from 1990s and 2000 and beyond. In addition, to the design stage, access to databases and abstracts that are presently available within the Federal and state archives in Mississippi and the United States Geological Surveys


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Table 2 The results of descriptive statistics. Counties Pearl River George Stone Harrison Hancock Jackson

1992 32,262 16,484 8,846 3,530 6,135 3,511

1997 28,907 11,907 8,671 4,514 9,271 11,882

Counties Pearl River George Stone Harrison Hancock Jackson

1998 2 5 1 2 2 5

2002 1 2 1 0 1 1


1992 93,180 43,498 32,666 16,665 30,050 24,845

1997 130,344 54,645 50,862 25,761 47,548 43,390


1992 9,961,000 6,897,000 4,530,000 1,951,000 2,139,000 4,902,000

1997 9,397,000 9,540,000 4,468,000 2,803,000 2,366,000 5,210,000


1998 46,939 18,592 13,223 186,249 40,885 128,412

2002 50,381 20,034 14,108 189,996 44,607 132,895

Acres fertilized % Change (1992-1997) -10.39 -27.76 -1.978 27.87 51.11 238.42 Impaired water areas 2004 % Change (1998-2002) 0 -50 1 -60 1 0 0 -100 2 -50 1 -80 Farm land 2002 % Change (1992-1997) 120,135 39.88 62,995 25.62 57,257 55.7 25,248 54.58 37,721 58.22 42,890 74.64 Agro sales 2002 % Change (1992-1997) 11,721,000 -5.66 13,050,000 38.32 6,959,000 -1.36 3,336,000 43.66 2,529,000 10.61 6,391,000 6.28 Population 2004 % Change (1998-2002) 51,719 7.33 20,711 7.75 14,458 6.69 192,129 2.01 45,821 9.1 134,935 3.49 2002 14,234 19,395 8,886 4,323 7,062 8,779

(USGS), United States National Aeronautical and Space Agency (NASA) and host of other entities quickened the search process. The spatial data was acquired from the USGS and the Mississippi Automated Resources Information System (MARIS) covering the southern Mississippi region of

% Change (1992-2002) -50.75 62.88 2.47 -4.23 -23.82 -26.11 % Change (2002-2004) -100 -50 0 100 0 % Change (1992-2002) -7.83 15.28 12.57 -1.991 -20.66 -1.152 % Change (1992-2002) 24.73 36.79 55.75 19.01 6.88 22.66 % Change (2002-2004) 2.65 3.37 2.48 1.12 2.72 1.53

Pascagoula-Biloxi Gulfport area for the separate periods of 1992 through 2004. 2.4 Step 2: Geo Spatial Data Acquisition and Processing For the study area of southern Mississippi region,

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multi-temporal spatial data made up of shape files and maps were obtained for the study. The data that were assembled for southern Mississippi Gulf region urban counties of Stone, Pearl River, Harrison, Hancock, George, and Jackson along the Pascagoula river basin region include socio-economic and ecological data, shape files, paper and digital maps from 1992 to 2004. All the spatial and temporal data were processed using ARC-VIEW GIS and SPSS. The outputs which emerged consist of texts, tables and maps as well as matrices. The processed data displayed under different legends makes ecological and stream habitat variables like water appear as common colors of black and white while the other socio-economic variables were distinguished in similar colors as well. Furthermore, the output was visually compared to see the changes across time and space along the tributaries of the southern Mississippi Gulf coast environment. The remaining procedure involves spatial analysis and output (maps-tables-text) covering the study period using ARCVIEW GIS. This process helped show the extent of temporal-spatial evolution of change induced by urbanization. It provided opportunities to undertake the sequential mappings of the stressors impacting the stream habitats in the south Mississippi Gulf region. The idea behind the process stems from the advantages of carrying out precise mapping of stream habitats using geospatial information systems in the region. Accordingly, the analysis of ecosystem health of stream habitats using Geographic Information Systems (GIS) to capture on going disturbances not only improves our knowledge of the scale of changes occurring in these systems, but it provides a framework for evaluating ecosystem decline and the mechanisms for restoration.

3. Results This part of the paper presents the results of descriptive statistics and temporal-spatial analysis of environmental change with GIS and correlation analysis on a set of indicators associated with stream

disturbance already outlined in the methodology. It consists of the snapshot of ecological variables of fertilized areas, impaired water areas, farmland etc., and socio-economic elements from population to agricultural sales in the region. This would be followed by a highlight of the factors responsible for change. 3.1 Environmental Analysis: Fertilized Acreages of Agricultural Land In terms of the size of acreages of land treated with fertilizer, the counties of Pearl River and George appear to have exceeded the other areas in the use of fertilizer nutrients. The use of fertilizers in Pear River ranged from about 32,262 acres in 1992, 28,907 during 1997 and 14,234 by 2002. Over the years (1992, 1997, and 2004) at George County, the size of agricultural land treated with fertilizer stood at 16,484, 11,907 and 19,395 acres. Within the same periods at Stone county, fertilizer acreages consists of 8,846 in 1992, 8,671 in 1997 and 8,886 in 2002. In 1992 about 3,530 acres were under the direct applications of fertilizer nutrients in Harrison county, in the following periods of 1997 and 2002, the size of fertilized areas stayed somewhat identical at 4,514 in 2002 and 4,323 in 2002. For Hancock county, land treated with fertilizers was estimated at 6,135 acres in 1992, 9,271 by 1997 and 7,062 during 2002. Between 1992, 1997 and 2002 in the Jackson county area, the numbers varied from 3,511 to 11,832 and 8,779 acres respectively (Table 2). On the percentages of change, it is seen that the counties were evenly split in terms of declines and gains in 1992-1997. In fact, three counties (Harrison, Hancock and Jackson) made gains while three other areas most notably Pearl River George and Stone saw their acreages of fertilized land decline. The breakdown of the figures show fertilized areas grew by 27% at Harrison, 51% at Hancock and by 238% in Jackson county. With the exception of 62% gains in fertilized areas for George and 2.4% for Stone county, the other remaining four counties experienced sizable declines in the period of 1992 through 2002 (Table 2).


3.2 Impaired Water Areas On the other environmental variables, in 1998, impaired water areas appeared more in the south Mississippi urban areas with three counties of Pearl River, Harrison, and Hancock each accounting for the 2 major water areas under impairment. In the same period, George and Jackson counties led the rest of the region with 5 impaired water areas while Stone emerged as the county with the least impaired water surface. Among the counties, in 2002 and 2004, only the George county and Hancock areas experienced water surface impairment in 2 areas while the rest had either one case of reported impaired surface or none at all (Table 2). 3.3 Farm Land The activities involving the use of agricultural shows Pearl River county had 93,180 acres of farm land in 1992. In the following periods, the size of farmland at the county reached 130,344 in 1997 and 120,135 in 2002. Within these periods, George county which opened the 1992 period with 43,498 acres saw its agricultural land areas jump to 54,645 acres in 1997 and 62,995 in 2002. At Stone county, the size of farmland rose from an initial value of 32,666 in 1992 to 50,862 in 1997 and 57,257 by 2002. In the same period, Harrison county used nearly 16,665 acres for farming in 1992, by the subsequent years of 1997 and 2002, farmland area in the county exceeded the 25,000 acres mark. Similarly, Hancock contained 30,050 in 1992 and it grew further to 47,548 in 1997 and 37,721 in 2002 while Jackson county which started with 24,845 acres in 1992 experienced increases of 43,390 and 42,890 acres in 1997 and 2002 respectively (Table 2). With the intense use of agricultural land in the study area, most of the counties posted double digit gains in percentages of change. To a great extent, three counties made up of Stone, Harrison and Hancock had parentages of change totaling over 53% between 1992-1997 while the rates of change for Pearl River county and George stood at 39.8% and 25%

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respectively. The county of Jackson finished ahead of the rest with the highest gain of 74% from 1992-1997. In 1992-2002, the rates of change in terms of decline were evident in the counties of Pearl River at -7.8%, Harrison with -1.9%, Hancock at -20%, while the rate for Jackson county stood at -1.1%. During that period, the two counties that experienced gains comprised of George at a rate of 15% and Stone with 12.5% (Table 2). 3.4 The Correlation Analysis To buttress linkages to behavior of some of the variables herein analyzed in contributing to stream habitat pollution, the simple correlation analysis performed on the 5 variables shows a positive relation between impaired waters and fertilized acres (Table 3). With the increase in fertilized acres, there came a rise in the number of impaired waters as well. Of all the counties under analysis, Jackson and George emerged as the most polluted counties with maximum number of impaired waters in 1998. This can be attributed to increases in the fertilized acres variable as both counties experienced a drastic rise in the acres of farm land treated with fertilizers resulting in nutrient flow into the adjacent waters and stream habitats. 3.5 Spatial Analysis On the spatial aspects of the factors threatening stream habitats, fertilizer use across space as the maps in Figs. 2(a)-2(c) show seemed quite pronounced in the periods of 1992, 1997 and 2002 in some counties. Note that the northern portion of the study area map highlighting Pearl River county had fertilized areas exceeding 20000 acres. Fertilizer use not only reached high levels, but the northern part appeared as the area with more fertilized areas in the 1992 and 1997, 2002 fiscal years (Figs. 2(a)-2(c)). On the number of impaired waters over the years, two counties (George and Jackson) both accounted for maximum levels of 3 and 5 cases of impairment in 1998 than the other counties in the study area (Fig. 3(a)). While most

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counties each had 1 and 2 cases of impairment in 2002 and 2004, note that the situation in Harrison showed no cases of impairment in the same periods. The same thing can be said of Pearl River county where number of impaired watersheds gradually disappeared in 2004 (Figs. 3(b)-3(c)). Turning to impaired watersheds from nutrient flow in the coastal counties, there was a high concentration of impaired water areas in the 1998 period with much of it located at George and Jackson, Harrison, Hancock and Pearl River (Fig. 4(a)). A closer look on the maps during the year 2002 and 2004 indicates a slight recurrence of impairment in minute clusters within the three counties notably Hancock, George and Jackson (Figs. 4(b)-4(c)). In terms of toxic release inventory sites, there seems to be a high dispersion of toxic release sites with much of it situated along the lower part of the study area in 1998. Of all the counties, Jackson, Harrison and Pearl River known for their proximity to sensitive watersheds had more toxic release facilities at the period (Fig. 5). On geographic diffusion of farming operations, the northern counties of Pearl River, Stone and George had intense agricultural activities measured around 30,001 to 50,000 acres in 1992 and over 50,000 acres in the 1997 through 2002 period (Figs. 6(a)-6(c)). Table 3

Part of the economic engine fueling ecological change in the region is evidenced by high growth in the sales of agricultural products. From the map, agriculture sales of more than $70000001 occurred more along the Pearl River and George counties most of the years while Jackson county also had sizable sales between 1997 and 2002 (Figs. 7(a)-7(c)). The spatial distribution of the population shows that in spite of demographic changes within all counties, the southern portion of the study area representing the counties of Jackson and Harrison had more population of and greater than 100,000 in the periods of 1998, 2002 and 2004. Both areas maintained a steady rise most of the time (Figs. 8(a)-8(c)). 3.6 Socio-Economic Factors Responsible for Stream Habitat Disturbance The extent and nature of environmental change leading to stream habitat degradation in the study area did not occur in a vacuum. Several socio-economic elements that played a role in the process are highlighted in this section of the paper. 3.6.1 Demography and Urban Growth The study area boosts of some of the most urbanizing areas including the city of Pascagoula. The area has been experiencing one of the most extensive

Summary of correlation analysis.

Variables and residuals Population

Farmland

Fertilized acres

Agro sales

Impaired waters

Pearson correlation Sig. (2-tailed) N Pearson correlation Sig. (2-tailed) N Pearson correlation Sig. (2-tailed) N Pearson correlation Sig. (2-tailed) N Pearson correlation Sig. (2-tailed) N

Population 1 18 -0.425 0.079 18 -0.438 0.069 18 -0.436 0.071 18 -0.159 0.53 18

** Correlation is significant at the 0.01 level (2-tailed).

Farmland -0.425 0.079 18 1 18 0.805** 0 18 0.752** 0 18 -0.243 0.332 18

Fertilized acres Agro sales -0.438 -0.436 0.069 0.071 18 18 0.805** 0.752** 0 0 18 18 1 0.725** 0.001 18 18 0.725** 1 0.001 18 18 0.01 -0.055 0.97 0.828 18 18

Impaired waters -0.159 0.53 18 -0.243 0.332 18 0.01 0.97 18 -0.055 0.828 18 1 18


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(a)

(a)

(b)

(b)

(c) Fig. 2 Number of acres fertilized in (a) 1992; (b) 1997; (c) 2002.

(c) Fig. 3 The number of impaired watersheds in (a) 1998; (b) 2002; (c) 2004.

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(a)

(b)

(c) Fig. 4 Impaired watersheds due to nutrient flow in (a) 1998; (b) 2002; (c) 2004.

Fig. 5 Spatial location of TRI sites in 1994.


Fig. 6 2002.

(a)

(a)

(b)

(b)

(c) The farmland (in acres) in (a) 1992; (b) 1997; (c)

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(c) Fig. 7 Total sales from agricultural products in (a) 1992; (b) 1997; (c) 2002.

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forms of urbanization brought about by rapid pace of economic development, proliferation of oil and gas activities and casino development. The request for residential and commercial housing permits as shown in Table 4 was significant in most of the counties. The role of residential and construction costs is quite evident in Hancock, Harrison and Jackson counties. Table 4 Building indicators.

(a)

Year 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Hancock county Building permits Construction cost $ 55 5,136,900 87 7,850,588 49 5,429,671 55 5,827,324 477 42,218,862 406 39,965,735 384 45,009,570 165 16,704,607 529 66,178,274 285 40,425,890 1,273 116,434,221 Harrison county

(b)

Year 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Building permits 1,022 929 1,119 1,272 1,213 1,010 1,131 1,272 1,364 877 2,223

Year 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Building permits 650 592 721 1,092 767 746 632 896 922 846 1,197

Construction cost $ 91,597,071 81,702,928 149,077,587 145,379,142 178,633,457 130,432,922 147,617,400 234,714,431 208,155,303 141,498,912 303,724,452

Jackson county

Fig. 8

(c) Population statistics in (a) 1998; (b) 2002; (c) 2004.

Construction cost $ 66,208,749 28,399,190 46,096,814 84,787,166 52,999,124 52,651,164 43,858,793 94,545,439 76,096,307 78,954,203 224,140,661


Looking at those counties between 1996 through 2006, it is evident that Harrison County had more building permits with construction costs estimated at tens and hundreds of million dollars. The percentage of changes for population from 1998-2002 as Table 2 shows indicate that the Pearl River and George counties both had growth rates of a little over 7% estimated at 7.3 and 7.7% while the population grew at 6.6 % at Stone county in the same period. Among the remaining counties, Harrison posted a percentage of change of 2%, Hancock’s population rose by 9.1% while Jackson experienced a population increase of 3.4%. The growth rates for 2002 to 2004 stayed at under 3% among the counties with two counties (Harrison and Jackson) having population growth rates of 1%. Another three counties (Pearl River, Stone, and Hancock) experienced growth rates estimated at slightly over 2% points while George county posted the highest gains of 3.3% (Table 2). These increases created high population concentration along the coasts adjacent to the basin at the expense of watershed ecosystem protection. 3.6.2 Economic Development and Agricultural Activities The economic activities in the basin embody those types that can impede the natural process of the watershed ecosystem. With a timber sector that generates over $300 million dollars in revenues and the presence of 75% of fossil fuel production, numerous drilling and mining activities are bound to live indelible ecological footprints in the form of severe disturbances on stream habitats all these years. The severity in channel and floodplain sand and gravel mining along the tributaries has raised concerns about the externalities unleashed from economic development. High level concentration of pollutants most notably PCBs, mercury, fecal coliform emanating from industrial and domestic sources have been reported in the river systems of the watershed. Other elements of urban change likely to impact the quality of habitats in the area can be evidenced from

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the pace of agricultural sales in the region. From the Table 2 Pearl River made sales worth about $9,961,000 in 1992, $9,397,000 in 1997 and $11,721,000 in 2002. George county followed in the same periods with $6,897,000 in 1992, $954,000 in 1997 and $13,050,000 in 2002. At Stone county, the amount of tradable goods from agriculture were 4,530,000 in 1992, 4,468,000 in 1997 and 6,959,000 in 2002. In the other counties, the Harrison area farm sales stood at $1,951,000, $2,803,000 and $3,336,000 in 1992, 1997 and 2002 respectively while Hancock made sales estimated at $2,139,000, 2,366,000 and $2,529,000. The medium level sales reported in the area include $4,902,000, $5,211,000 and $6,391,000. The percentages of change in farm sales show very significant gains in 1992-1997 and 1992-2002 most of the time (Table 2). The externalities from agriculture in the form of nutrient flow into watersheds threaten the quality of biodiversity habitats.

4. Discussion The results not only reveal that the study area experienced some changes across time and space but the estuarine environments and stream habitats are threatened by urbanization elements. In light of that, the regions adjoining natural areas remain an ecosystem under stress. Overall, the result of the data analysis point to signs of growing incidence of pollution involving extensive fertilizer use and the impairment of water bodies. The presence of toxic facilities in the region exposes the region’s natural systems to a great danger. The increases in human settlement indicators as indicated by population growth and the requests for building permits and the level of agricultural intensification needed to feed urban populace led to loss of arable farmland around the surrounding ecology. Increased agricultural land use activity known to precipitate large use of agrochemicals and other type of nutrients as the analysis showed grew to a great extent at very significant rates especially in Pearl River, Stone,

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George and Jackson counties. In the process, many of the study area stream corridors or habitats in the urban counties were greatly impaired. Under this setting, indicators like agricultural activities likely to spur pollution through fertilizer use as well as toxic inventory release sites were quite visible in the counties. Although several counties experienced double digit gains in the use of agricultural land, the downside is that under current practices, those gains often resulted into more use of fertilizers to boost agricultural productivity. This creates further impairment of stream corridors already over stretched with heavy load of nutrients and other contaminants beyond their carrying capacity. The loss of farmland to other land uses most notably urbanization still does not bode well for sustainability and ecological design approach and the environmental welfare or the carrying capacity of the sensitive stream habitats in the Mississippi Gulf region. The loss of farmland in such costal areas experiencing conversion of adjoining wetlands to urbanization seemed to have aided building construction. This leads to more impervious surfaces through which the flow of pollutants and toxic chemicals from roadways empty directly into sensitive estuarine habitats. Thus, gains and losses in agricultural land in the study area symbolizes a double edged sword for stream habitat planning since the emergent land use activities from these changes facilitates pollution of open streams in the region. With population exceeding over 100,000 in the Jackson and Hancock areas, it is evident that some of the counties along the coast have very high concentration of human populations likely to exert pressure on the environment and the sensitive natural habitats in the ecosystem. In an area sprawling with growth, there are bound to be requests for new development projects in the form of new housing and road designs likely to create more impervious surfaces at the expense of stream habitat health. At the same time, socio-economic indicators of agricultural sales,

building permits and construction costs as a measure of the intensity of land activities and transactions seemed quite pronounced. Large volume of investments resulting from high agriculture sales and boom in construction can put some added stress on the sensitive watersheds as run off from agriculture and construction sites empty into watersheds already stressed beyond their carrying capacities. All these point to the role of socio-economic and human factors fueled by urbanization in precipitating stream habitat impediment in an ecosystem. This seemed to reflect the ecosystem approach that often represents the most appropriate level of organization for analyzing human influences on ecological systems. It can play a central role in the design and analysis of alternatives and future lines of action. To buttress the linkages among some of the variables in fuelling change, a correlation analysis confirmed a direct relationship between impaired water surfaces and fertilizer use in the region. The environmental change analysis using geospatial information tool of GIS in the area identified a cluster of counties where land use activities involving agricultural farming and the widespread applications of fertilizers threatening urban environments and stream habitat ecosystem remained very active. From the spatial and temporal analysis, the region’s stream corridors appear threatened by the gradual pace in the impairment of water bodies in certain areas and toxic site inventories. In fact, the proliferation of toxic inventory sites seem fully concentrated along the watersheds and the tributaries of rivers along the urban environments due to intense development and human activities. In light of this finding, the practical use of a mix scale approach involving GIS in tracking the extent to which urbanization had impacted and contributed to stream habitat change in coastal environments of southern Mississippi region stands as an update to the current literature on ecosystem restoration. With the meager efforts in the past to assess the impacts of urbanization along the Southern Mississippi River


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stream habitat ecosystem, geospatial technology of GIS as demonstrated in this project has been quite effective in ensuring the mapping of change related information on the watershed with a spatial reference. As an effective tool for resource management, integrated data analysis using GIS facilitated the analysis of the spatial distribution of stream habitat change involving land use and hydrology and the demographic issues facing the south Mississippi river basin environment. Such spatial information technology is desirable for policy makers in the Mississippi area as they deal with the emerging problems threatening the environment along the region’s stream habitats. To deal with the concerns raised in this research, this section of the paper provides four suggestions anchored in ecosystem approach and the principles of sustainability. The recommendations for mitigating the problems range from policy considerations, coastal zone planning, and the design of spatial information systems and the adoption of ecosystem approach.

current pressures mounted on the stream corridors by urbanization in the study area.

4.1 Adopt Effective Policy

4.3 Promote Periodic Monitoring and Design of Spatial Information System

The land use regulations and zoning laws operational in the state have several lapses that threaten the environmental welfare of citizens and other life forms along the basins. Just as land developers in the area constantly gain approvals for switching general development plans to commercial types with little recourse to cumulative impacts on the ecosystem. So are the growing vulnerability of quality of streams, lakes and the ecosystem health to the impairment and threats created by mining activities, silver culture and industrial development. Because current policies have done little to mitigate the inherent ecological problems on the estuarine environments, the paper suggests the adoption of effective policy instruments to ensure enforcement and a better framework for protecting the environment. This will go along in straightening the mitigation measures necessary in containing the

4.2 Encourage Urban Costal Zone Planning Part of the mandate of planning is to promote the quality of life and the environment in coastal areas by involving multi-stakeholders including the decision makers and those whose livelihoods are impacted by development in the planning process through a set of goals. Considering the scale of pressures unleashed on the natural ecosystem by the built environment through urbanization in study area, the paper suggests the need for coastal zone planning in the region built on the conservation of natural areas especially stream corridors. Sensitive natural areas and habitats for biodiversity, endangered plants and animals along the Pascagoula watershed should be zoned as protected areas. This should be enforced with strict controls on future development activities along the shores of the watershed so that erosion and sedimentation problems experienced in the area can be minimized.

The state of ecological health of the basin calls for regular monitoring, observation and assessment of land, sea, atmosphere, and open space in order to create a data collection network to track earth’s changing systems using spatial information. This approach would not only aid decision makers to understand how stream habitats and natural systems of the Gulf region work, but it provides opportunities for counties to partner together through yearly assessments of their conditions. It will also enable managers assess and predict change and interactions within natural systems such as watershed. This could be attained by providing future information for managing coastal resources in order to optimize their benefits to the environment, economy and society in line with ecosystem principles and sustainability.

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4.4 Support Ecosystem/Watershed Approach The ecology of aquatic life shares close linkages with the conditions of a watershed’s terrestrial ecosystems. Yet society does not fully understand how stresses from human activities, such as land development, pollutant releases, deforestation, river channelization and agriculture affect these common linkages in the basin. Under this setting, the Pascagoula Watersheds as the basic units of land and surface water in the Southern Mississippi area merit continuous protection. This approach supports research that cuts across all disciplines with potentials for applying the principles of watershed restoration for the common good of communities at risk. The emphasis should be on the integration of ecological-socio-economic studies by taking into account the human factors associated with watershed stress under the aegis of ecosystem design approach.

stressors made up of fertilizer applications, number of impaired watersheds, the use of farmlands and pollution inventory sites were on the rise especially in areas adjacent to urban watersheds. Other aspects of the results show that socio-economic factors of population, income from agricultural sales and building permits grew in some of the areas. The pressures unleashed from these variables as the analysis indicates accentuated the strain on the region’s ecosystem. The environmental change analysis in the area using GIS identified a cluster of several land cover types in the form of agricultural areas under use, size of land under fertilizer use, impaired water areas and diffusion of socio-economic indicators (stress sources) in space in affected areas. Accordingly, the application of GIS as demonstrated in this paper has been quite effective in ensuring the sequential mapping of stress factors along the southern Mississippi region. Being a valuable

5. Conclusions From the onset of the paper, the literature rightfully identified the threats urbanization poses to stream habitats. Using geospatial technology of GIS, the paper shows that human-environment interaction results in degradation of stream habitat corridors. The assessment of urbanization impacts on stream corridors using GIS not only enhances our understanding of the scale of changes occurring in these systems, but it provides a framework for evaluating ecosystem decline and the mechanisms for restoration. Nonetheless, in the past years, widespread level of urban development triggered by anthropogenic activities has been eroding the environment and support systems along the southern Mississippi study area. The results not only reveal that the study area experienced some significant changes in its watershed environments, but the stream habitat in the area remains an ecosystem under stress. Overall, the results point to threats to water quality, growing incidence of pollution, impairment of water bodies, and increase in human settlement, and agricultural intensification. Ecological indicators and

device for resource management, integrated data analysis through GIS quickened the assessment of geographic diffusion of urbanization impacts on stream habitats

and

change

involving

land

use

and

demographic elements of urbanization threatening stream habitats. As part of the remedies, the paper offered four recommendations built on ecosystem approach and sustainability principles. The suggested actions for restoration offered here ranging from effective policy to ecosystem approach would go a long way in ensuring a speedy mitigation of the problems. Finally, geospatial information technology as used in this project would continue its emergence as a valuable device for policy makers in the state as they confront stressors threatening the environment along the southern Mississippi coastal region in the years ahead. Adopting such an approach can provide planners information about the casual effects of disturbances in ecosystems. This would help them contribute to a more effective urban management in terms of environmental protection and the infusion of ecological design principles in practice.


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[16]

Y. Richard, Footprints on the earth: The environmental consequences of modernity, American Sociological Review 68 (2003) 279-300. M. Joan, C. David, Platform changes in rivers with and without instream and floodplain sand and gravel mining: Assessing instability in the pascagoula river tributaries, Mississippi, Department of Geography, University of Florida, Gainesville, 2005. B. Jie, L.D. Chen, Integrating landscape ecological principles and land evaluation for sustainable land use, Journal of Environmental Science 11 (1999) 136-140. N. Richard, Striking the balance between environment and economy in coastal North Carolina, Journal of Environmental Management 49 (2005) 177-207. S.Y. Fan, Principles and practice of ecological design, Environmental Review 12 (2004) 97-112. M.C. Edmund, Y. Twumasi, GIS applications in land management: The loss of high quality land to land development incentral Mississippi from 1987 to 2002, The International Journal of Environmental Research and Public Health 2 (2005) 234-244. M.C. Edmund, Y. Twumasi, GIS based analysis of growth management and environmental decline in seven counties of Central Mississippi region, Annals of GIS (CPGIS) 11 (2005) 130-137. P.H. Nienhus, Water and values: Ecological research as the basis for water management and nature management, Hydrobiology 565 (2006) 261-275. T. Hale, Opportunity costs of residential best management practices for storm water runoff control, Journal of Water Resources Planning and Management 132 (2006) 89-90. P. Janet, Neglected sources of ozone, Environmental Science and Technology 38 (2004) 365A-366A. P. Wendy, Research: Stormwater drainage is reducing stream biodiversity, Ecos 35 (2004) 1. T. Susanna, C. Wenli, Modeling the relationship land use and surface water quality, Journal of Environmental Management 66 (2002) 377-393. WCED (World Commission of Environment and Development), Our Common Future, Oxford London: UK, University Press, 1986. H. Edwin, S. Jian-Ping, Integrated analysis of water quality and physical in the ecological design of water resources project, Journal of Environmental Science and Health 41 (2006) 1303-1314. V. Peter, Ecosystem science and human environment interactions in the Hawaiian Archipelago, Journal of Ecology 94 (2006) 510-521. M.C. Edmund, Y. Twumasi, GIS and remote sensing applications in the assessment of change within a coastal

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environment in the Niger Delta region of Nigeria, The International Journal of Environmental Health and Public Health 3 (2006) 98-106. M.C. Edmund, Y. Twumasi, Hydro-politics: A case of the Niger river basin, GIS Development-Africa 7 (2006) 24-28 M.C. Edmund, Y. Twumasi, Using GIS and remote sensingin the analysis of ecosystem decline along the river Niger basin: The case of Mali and Niger, The International Journal of Environmental Health and Public Health 4 (2007) 278-289. M.C. Edmund, Y. Twumasi, GIS applications in global environmental protection: The case of environmental monitoring of fossil fuel emission from oil and gas activities in Africa, World Resources Review, 2007. D. Angela, The Development of Decision System for Prioritizing Forested Wetland Restoration Areas in the Yazoo River Basin Mississippi, US Environmental Protection Agency ,Washington D.C., 2007. S. Gaurav, Remote sensing and geospatial applications for watershed delineation, Department of Civil Engineering, Mississippi State University, 2005. MDEQ (Mississippi Department of Environmental Quality), State of Mississippi water quality assessment, 305 b Report Addendum, Jackson Mississippi, 2004. M.S. Veal, Coastal zone impacts of the dockside industry the Mississippi experience, in: Proceedings of Workshop Held in Biloxi Mississippi, Office of Agricultural Communications, Division of Agriculture, Forestry, and Veterinary Medicine, Mississippi State University, May 7-8, 1996. G. Cyntia, Dubious delistings: Mississippi’s push to remove protections for polluted waters, Gulf Restoration Network, New Orleans LA, 2002. T. Mary Love, Water quality and land use investigations in the upper pearl river basin of east central Mississippi, Ph.D. Thesis, Department of Soil Sciences, Mississippi State University, 2006. MDEQ (Mississippi Department of Environmental Quality), Pascagoula River Basin, available online at: http://www.deq.state.ms.us/mdeq.nsf/pageWMB_Pascag oula_ River_ Basin (assessed on 3/10/2007). NRECS (Natural Resources Conservation Services), Pascagoula River Watershed, United States Department of Agriculture, available online at: http://www.ms.nrcs.gov/programs /Pascagoula (assessed on 3/10/2007). E. Larry, Basin profile: Pascagoula river basin, Environmental News 3 (2006) 1-5. H. Matthew, Conserving Mississippi’s Freshwater Biodiversity, Nature Conservancy, Mississippi Chapter Jackson, 2005.


D DAVID

PUBLISHING

Assessing the Production of Sugarcane-Derived Ethanol in Iran as a Transport Fuel from Economical and Environmental Point of View Sh. Bahadori Faculty of Economic and Administrative Sciences, Ferdowsi University of Mashhad, Mashhad 9177948974, Iran Received: May 16, 2011 / Accepted: June 16, 2011 / Published: December 20, 2011. Abstract: Bioethanol is an attractive renewable energy resource that can be produced from agricultural feed stocks such as sugarcane, corn, sugar beet, wheat, barley and many types of waste biomass materials. It can be used as a transport fuel, mainly as a biofuel additive for gasoline called “gasohol”. In this study the possibility of using ethanol as a gasoline additive from economic, environmental and agricultural point of view in Iran is investigated. Daily gasoline consumption of Iran is about 66 million liters and 34% of this amount is imported. We consider the production of sugarcane-derived ethanol to displace 15% of gasoline use in Iran. With existing technology, 450,000 hectares of land, 21 standard distillery and US $3,600 million investment will be required to produce this amount of ethanol. This is just about 60% of the money that currently Iran expends annually for importing about 5.8 million tones of gasoline. Key words: Bioethanol, sugarcane, biofuel, gasoline, gasohol.

1. Introduction World ethanol production for transport fuel tripled between 2000 and 2007 from 17 billion to more than 52 billion liters. From 2007 to 2008, world fuel ethanol production increased 32% and the share of ethanol in global gasoline type fuel use increased from 3.7% to 5.4%. Brazil and the United States were responsible for 89.2% of the world’s ethanol fuel production in 2008 [1]. These statistics clearly show the importance and world tendency for using ethanol as a transport fuel. Therefore, it is completely important for Iran that by dependence to imported gasoline, high crude oil prices, non renewability of fossil fuels and global warming something has to be done to reduce dependence and emissions derived from fossil fuel combustion. Ethanol can be produced from sugarcane Corresponding author: Sh. Bahadori, master, main research fields: renewable and non-renewable energy resources and energy economics. E-mail: [email protected].

in Khuzestan province with minimal environmental impact and in sufficient quantities to be part of the solution. Today Khuzestan is responsible for more than 99% of sugarcane produced in Iran [2] and can play an important role in satisfying future ethanol demand. The proper climate, fertile lands and industrial implant allows sugarcane production at high yields even more than global average. The total production of sugarcane has rapidly increased in the previous decade. This increase is attributed to a combination of higher yields and seeded area. The study’s objective is to evaluate the Khuzestan’s potential for substituting 15% (3600 million liters annually) of the domestic demand of gasoline by sugarcane-derived ethanol. The study covered issues such as resources: land, people, infrastructure, as well as economic, environment and social impacts for the country due to this projection of major increase in ethanol production. We report here on the land and

Assessing the Production of Sugarcane-Derived Ethanol in Iran as a Transport Fuel from Economical and Environmental Point of View

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infrastructure requirements and potential environmental impacts of the proposed project.

2. Importance of Ethanol Ethanol is an alternative fuel for gasoline that is receiving great attention worldwide because it is a renewable and environmental friendly fuel therefore its rate of consumption is increasing dramatically recently. As you can see in Fig. 1, global fuel ethanol

Fig. 1

World ethanol production.

equivalent (1.2 million barrels per day on volumetric

4. Suggested Project of Ethanol Production in Iran

basis) in 2008 [3]. Ethanol can be used either pure or

Iran gasoline consumption is about 66 million liters

in blends with gasoline but at low concentrations it is

per day, slightly more than 24 billion liters per year.

not necessary to do any modification in spark-ignition

The study assesses to provide 15% of current gasoline

(SI) engines but for using pure ethanol some

consumption by sugarcane derived ethanol as a

modifications are necessary [4]. E15 (ethanol 15% and

gasoline additive. To achieve this goal Iran should

gasoline 85% by volume) is a low concentration blend

produce about 3.6 billion liters ethanol annually.

and the most common combination of ethanol and

About 85 liters of ethanol can be extracted from one

gasoline that is suited renewable, bio-based and

tone of sugarcane based on current technology.

eco-friendly for spark-ignition (SI) engines. Due to

Therefore 42,350,000 tonnes of sugarcane should be

mentioned environmental and economic benefits of

produced. With average yield of 94 tonnes per hectare

E15, this ratio has been chosen.

of sugarcane it would take 450,000 hectares of

production grew 31% to 35 million tones of oil

3. A Brief Review of Sugarcane Production in Iran

sugarcane to provide enough feedstock to meet the projected demand of 3.6 billion liters of ethanol. Khuzestan because of its climate conditions, dry

Production of sugar from sugarcane was undertaken

growing season and abundant and productive land has

in the 1950s along the Caspian Sea and Mazandaran

a high capability of producing sugarcane. There are a

province on a small scale. Food and Agriculture

lot of proper sites for cultivating sugarcane in

Organization (FAO) invited foreign experts to

Khuzestan as you can see in Figs. 2 and 3 [6]. For

Khuzestan to conduct feasibility studies on sugarcane

example the irrigable soil in vicinity of Karkheh and

cultivation and in June 1957, the study proposed

Dez dam and the basin of Karun River respectively in

cultivation of sugarcane near Shoush city in an area of

north and southwest of Ahwaz and also the alluvial

12,000 hectares. Later, Haft-Tappeh Company was

dry soil in south of Ahwaz have high capability for

established for the purpose [5]. Based on official

cultivating sugarcane if the water is supplied.

announcement of Agricultural Jihad Ministry 60,946

Khuzestan currently has 2,488,608 hectares pasture and 1,146,700 hectares cropland. Of the cropland, 973,125 hectares are used for grains, 84,232 hectares are used for industrial products such as sugarcane and sugar beet, 42,092 hectares are used for vegetables, 36,798 hectares are used as melon bed and 10,453 are

hectares with average yield of 87 tonne/ha is dedicated to sugar cane

production in 2007. The

yield

reached to 94 tonnes per hectare in 2009 but the land under sugarcane cultivation is not formally announced yet [2].

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Fig. 2

Khuzestan geological map.

Fig. 3

Khuzestan farm land map.

used for provender and other products. Sugarcane cultivation can be expanded only in 18% current pasture area of Khuzestan. Therefore, there would be no competition between food and fuel. A standard distillery (ethanol mill) is defined as a mill crushing 2 million tonnes of sugarcane per year and producing 1 million liters per day of fuel ethanol during 170 days of operation (totally 170 million liters

ethanol per year) based on current technology [7]. Therefore, 21 standard distilleries are necessary for producing 3.6 billion liters of ethanol annually. We can divide these distilleries to some clusters which can be placed in the areas that have agricultural capability to support sugarcane production and logistics for ethanol shipment. These standard distilleries produce only ethanol and bagasse is used for producing electricity to supply energy demand of each facility. Excess electricity can be sold to the grid. The cost of each ethanol mill is estimated at US $100 million for implementing facility and an additional US $40 million agricultural related investment. The total investment would be around US $3 billion plus anther US $600 million for implementation of new sugarcane production. Total cost of project is estimated to be US $3.6 billion. Total cost of the project is just about 60% of the money that currently Iran expends annually for importing 5.8 million tones of gasoline (price of gasoline is US $1,050 per tone) [8]. Each ethanol mill will produce 170 million liters of ethanol and 80 GW·h of electric energy per year. Price of electricity is about US $0.08 per kW·h [9] and price of gasoline is US $1,050 per tonne. We use ethanol as substitute of gasoline therefore if we consider the same value for produced ethanol the investment will result in total revenue of around US $125 million for each ethanol mill and overall revenue of US $2,625 million for whole 21 ethanol mills annually and we should subtract the cost of production from the overall revenue. Price of raw sugarcane is US $33 per tone and the processing cost of produced ethanol is US $0.20 per liter [10]. Therefore, the production cost of produced ethanol will be US $0.59 per liter. Total cost will be US $2,125 million for producing 3.6 billion liters annually. If we subtract the total revenue from total cost, we will have the net profit that is equal to US $500 million. The implementation of this project will generate about 180,000 direct and indirect jobs [11]. Also by


implementation of this macro project locals will benefit from social development as construction of homes, hospitals, public services, communication and transportation.

5. Environmental Impacts of the Project Replacing fossil fuels such as gasoline and diesel fuel by biofuels is a very controversial topic among researchers. In this section the environmental impacts of using ethanol are discussed and the other impacts are discussed in the next section. If we consider ethanol use in environmental point of view, Net Energy Ratio should be discussed (NER is the output of renewable energy per input of fossil energy). Fossil energy for agricultural-based production includes fossil fuels to drive tractors, produce fertilizer and other chemicals, as well as providing process heat for biofuel production, etc.. If this indicator is zero, it means that the fuel is not renewable at all and it also does not produce useful energy. If the indicator is 1, the fuel is still considered as non-renewable. An infinite indicator shows that the fuel is absolutely renewable and any value higher than 1 shows that the fuel is renewable up to a certain point. Brazilian sugarcane-derived ethanol has a net energy ratio of about 8.0 [12] meaning that there is 8 times more energy in produced ethanol than fossil energy used for its production. This is because of the biomass use (bagasse) in the production process of ethanol. Therefore, one can conclude that sugarcane-derived ethanol to some good point is renewable and eco-friend. NER can be improved by increasing the sugarcane yields and new technology therefore Iranian sugarcane-derived ethanol will have a greater NER than Brazilian due to higher yields (currently sugarcane yield in Iran is 32% greater than brazil). Therefore, the derived ethanol from this projection in Khuzestan province will have a NER of about 10 based on current yields and this ratio can be increased by improved farming techniques, more efficient use of fertilizers and pesticides, higher-yielding

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crops, and more energy efficient conversion technology. According to US Department of Energy (DOE) cellulosic ethanol reduces greenhouse gas emissions (GHG) by 86% over reformulated gasoline and sugarcane-derived ethanol reduces GHG emissions by 78% while corn-derived ethanol based on the kind of energy used for the process (e.g. petroleum, natural gas or biomass) reduces greenhouse gas emissions from 19% to 52% over gasoline [13]. With abundant gas reservoirs in the Khuzestan province of Iran, natural gas as a clean and cheap source of energy can be used in ethanol mills instead of bagasse that is currently burned as fuel in sugarcane mills. Therefore, the rate of GHG emissions will be reduced too much over gasoline and also the remained bagasse can be used as a source for producing cellulosic ethanol. Puppan [14] shows that biofuels have a close carbon cycle and during the combustion of biofuels in the engines, emissions of CO2 correspond to the amount that was absorbed from the atmosphere during the growth of these plants. Therefore, the total CO2 emission due to the ethanol fuel in the exhaust of engines is absorbed by the plant from the atmosphere. According to this point the biofuels can be a solution for global warming and they will play a significant role to mitigate global warming rate. Also a survey which has been done by Najafi et al. [15] indicates that by using ethanol-gasoline blends the concentration of CO and HC emissions in the exhaust of SI engines and also brake specific fuel consumption (bsfc) will decrease. In addition ethanol readily biodegrades without harm to the environment, and is a cheap and eco-friendly source of increasing gasoline octane number as substitute of lead or MTBE additives. Octane number of regular unleaded gasoline is 87 while the octane number of E85 is 105, therefore, ethanol enhances engine performance [16]. Despite of the above environmental advantages of using bioethanol there are some disadvantages such as

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the use of large amounts of water, the destruction of forests, the reduction in food production and the increase in soil erosion. With increasing ethanol production, water availability has recently become an issue of concern. For instance, in the US Midwest the Ogallala aquifer, which underlies most of the US corn belt, has decreased over 100 ft since the 1940s [17]. This shows that human water use is exceeding the ability of aquifer recharge. Corn ethanol production with existing technology requires 3-4 L of water per liter of ethanol in the processing phase, while water use for Brazilian ethanol due to sugarcane washing is 50 L water per liter of ethanol [18]. Therefore, efforts are necessary to mitigate any adverse effects and improve water efficiency in aforementioned projection in Khuzestan. Food vs. fuel and forest destruction are the risks of diverting crops for ethanol production. The debate is internationally controversial, with good-and-valid arguments on all sides of this ongoing debate. But in this project sugarcane cultivation is expanded only in 18% current pasture area of Khuzestan that is not used as a farmland. Therefore, the competition between food and fuel and forest destruction will not be happened in this project. Ethanol-enriched gasoline conducts electricity in contrast to gasoline, which is electrical insulator. Therefore, the rate of corrosion of underground storage tanks increases and the risk of leakage to surrounding soil will increase. Also the presence of ethanol in gasoline increases the solubility of petroleum constituents such as benzene, toluene, xylenes and ethylbenzene in water and so there is great concern over groundwater protection [19].

6. Other Impacts of the Project It is observed that the production of ethanol and other biofuels is mainly based on agriculture raw materials and, therefore, many countries can easily produce it attaining several benefits such as a greater

energy security, diversification of energy sources and agriculture, accelerated development of rural areas with the consequent increase in job opportunities in these areas. But instead of these advantages there are some concern such as diverting agricultural resources to fuel instead of food production, use of large amounts of water, the possibility of destruction of forests and pasture and increase in soil degradation [20].

7. Conclusion Energy security, need to mitigate the greenhouse effect and high crude oil prices are the great incentives for the world over ally and Iran especially, for using ethanol as new source of energy. The discussion here illustrates that large amounts of sugarcane-derived ethanol can be produced in Khuzestan province and can be used as gasoline additive in an environmentally responsible way. But the biofuel production projects should be carried out with full cautiousness. Choosing the proper region respect to weather, fertile lands and other criteria for cultivating agricultural products, having the minimum environmental effects and implementing the project in non cropland farms are some points that should be considered. Also it is important to realize that no single fuel or technology such as sugarcane-derived ethanol can replace fossil fuel alone. Meeting future demands will require new technologies such as improve and lowering the fuel consumption of engines and development of multiple fuels. No technology currently has a zero environmental and social impact but we should develop the best ways that have the least impact.

Acknowledgments The author would like to acknowledge the support of my family, and also Saeid Javedan Nejad and Abbas Hosseini, chief engineers of Aghagajari Oil and Gas Producing Company. They provided valuable comments.


References [1]

Renewable Fuels Association, available online at: http://www.ethanolrfa.org/pages/statistics. [2] Agricultural Jihad Ministry of Iran, Agricultural statistics, available online at: http://www.maj.ir. [3] Statistical Review of World Energy 2009, available online at: http://www.bp.com/liveassets/bp_internet/globalbp/globa lbp_uk_english/reports_and_publications/statistical_ener gy_review_2008/STAGING/local_assets/2009_download s/statistical_review_of_world_energy_full_report_2009.p df. [4] M. Koc, Y. Sekmen, T. Topgul, H.S. Yucesu, The effects of ethanol–unleaded gasoline blends on engine performance and exhaust emissions in a spark-ignition engine, Renewable Energy 34 (2009) 2101-2106. [5] Iranian Sugarcane & By-Products Development Company, available online at: http://www.sugarcane.ir/kteportal/Default.aspx?PI=KTIt wgW+sHkAM4W4pAyATg==. [6] Khuzestan Forests, Range & Watershed Management Organization, available online at: http://www.khuzestan.frw.org.ir. [7] R. Leite, M. Leal, L. Cortez, W.M. Griffin, M. Scandiffio, Can Brazil replace 5% of the 2025 gasoline world demand with ethanol?, Energy 34 (2009) 655-661. [8] Abadan Oil Refining Co., available online at: http://www.abadan-ref.ir/fa/shownews.aspx?ID=219. [9] U.S. Energy Information Administration (EIA), available online at: http://www.eia.doe.gov/emeu/international/elecprih.html. [10] United States Department of Agriculture (USDA), available online at: http://www.ers.usda.gov/Briefing/Sugar/Data.htm. [11] M.P. Cunha, J.A. Scaramucci, Bioethanol as basis for

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regional development in Brazil: An input-output model with mixed technologies, in: 46th Congress of the European Regional Science Association (ERSA), 2006. H. VonBlottnitz, M.A. Curran, A review of assessments conducted on bio-ethanol as a transportation fuel from a net energy, greenhouse gas, and environmental life cycle perspective, Journal of Cleaner Production 15 (2007) 607-619. U.S. Department of Energy (DOE), available online at: http://www.energy.gov/news/archives/documents/biofuel s_greenhouse_gases_myth_and_facts.pdf. D. Puppan, Environmental evaluation of biofuels, Periodica Polytechnica Series Social and Management Sciences 10 (2002) 95-116. G. Najafi, B. Ghobadian, T. Tavakoli, D.R. Buttsworth, T.F. Yusaf, M. Faizollahnejad, Performance and exhaust emissions of a gasoline engine with ethanol blended gasoline fuels using artificial neural network, Applied Energy 86 (2009) 630-639. V. Thomas, A. Kwong, Ethanol as a lead replacement: Phasing out leaded gasoline in Africa, Energy Policy 29 (2001) 1133-1143. National Academy of Science (NAS), Water implications of biofuels production in the United States, available online at: http://dels.nas.edu/dels/rpt_briefs/biofuels_brief_final.pdfs. Sao Paulo Sugarcane Agro Industry Union, available online at: http://www.portalunica.com.br/portalunica/?Secao. R.K. Niven, Ethanol in gasoline: Environmental impacts and sustainability review article, Renewable and Sustainable Energy Reviews 9 (2005) 535-555. J.C. Escobar, E.S. Lora, O.J. Venturini, E.E. Yanez, E.F. Castillo, O. Almazan, Biofuels: Environment, technology and food security, Renewable and Sustainable Energy Reviews 13 (2009) 1275-1287.


D DAVID

PUBLISHING

A Survey on a Heat Exchangers Network to Decrease Energy Consumption by Using Pinch Technology B. Raei and A.H. Tarighaleslami Chemical Engineering Faculty, Mahshahr Branch, Islamic Azad University, Mahshahr 63519, Iran Received: April 27, 2011 / Accepted: July 7, 2011 / Published: December 20, 2011. Abstract: There are several ways to increase the efficiency of energy consumption and to decrease energy consumption. In this paper, the application of pinch technology in analysis of the heat exchangers network (HEN) in order to reduce the energy consumption in a thermal system is studied. Therefore, in this grass root design, the optimum value of ∆Tmin is obtained about 10 °C and area efficiency (α) is 0.95. The author also depicted the grid diagram and driving force plot for additional analysis. In order to increase the amount of energy saving, heat transfer from above to below the pinch point in the diagnosis stage is verified for all options including re-sequencing, re-piping, add heat exchanger and splitting of the flows. Results show that this network has a low potential of retrofit to decrease the energy consumption, which pinch principles are planned to optimize energy consumption of the unit. Regarding the results of pinch analysis, it is suggested that in order to reduce the energy consumption, no alternative changes in the heat exchangers network of the unit is required. The acquired results show that the constancy of network is completely confirmed by the high area efficiency infirmity of the heat exchanger to pass the pinch point and from of deriving force plot. Key words: Pinch technology, heat exchangers network, energy consumption, composite curve, grand composite curve.

1. Introduction At the end of 1970s, Umeda [1] and his co-workers in Chiyoda established new technology for optimization of process. During 1978 to 1982, this team by presenting of the concept of processes analysis and composite curve showed how the utility consumption can be evaluated and heat recovery and reduction can be done with using this method. At the same time, Linnhoff [2] and his co-workers considered the analysis of heat exchangers network (HEN) for energy consumption reduction and introduced the concepts such as composite curve as an important tool for heat energy recovery. But contrary to Chiyoda team, they emphasized on a pinch point as a key point for heat recovery and by this reason they chose the name of

A.H. Tarighaleslami, lecturer, main research fields: process integration and energy saving technology. E-mail: [email protected]. Corresponding author: B. Raei, lecturer, main research fields: process integration and energy saving technology. E-mail: [email protected].

pinch technology for this method. When the time passed, pinch technology has been developed. As the same as HEN, it is used for optimization of energy consumption in distillation towers, furnaces, evaporators, turbines and reactors. Pinch technology is a systematic method based on first and second laws of thermodynamic, which is used for analysis of chemical processes and utilities. Pinch analysis of an industrial process is used for definition of energy and capital costs of HEN before design and also definition of pinch point. In this method, before design, minimum consumption of utility, minimum demanded network area and minimum number of demanded heat unit at pinch point are targeted for given process. At next stage, design of HEN will be done to satisfy performed target. Finally, minimum annual cost is obtained with comparison between energy cost and capital cost and trade of them. Therefore, the main goal of pinch analysis is the optimization of process heat integration, increase the process-process heat recovery, and decrease the amount of utility consumption [1]. For

A Survey on a Heat Exchangers Network to Decrease Energy Consumption by Using Pinch Technology

analysis, at first, shifted temperature is obtained then temperature and enthalpy plot draw (half of amount of minimum temperature are deducted from hot stream and added to cold stream). Fig. 1 shows the composite curve and grand composite curve as tools for pinch analysis. The composite curves (CCs) present the relationship between cumulative enthalpy flow rate and temperature for the HEN hot and cold streams. In practice, CCs are generated by a cumulative process over a temperature range, and the resulting hot and cold CCs are labelled CCh and CCc, respectively [3].

2. Methods and Data 2.1 Presentation of a Heat Exchanger Network In a heat exchanger network, arrangement of exchangers in the network is important. For representing such arrangement, the concept of “stage” is used. In every stage, the input and output heat of the stage is equal for the entire exchangers that settled on special stream, whereas the number of stages is not too

many in an optimal network [4]. In this part, stages of heat exchanger networks analysis for reduction of energy consumption using pinch technology were explained. Since targeting and design is based on extracted data any mistake and careless in data assembling can lead to completely unreal results. In pinch analysis, design data such as supply and target temperature of streams, flow and heat capacity of stream was used and on the other hand, heat exchangers design was related to heat transfer coefficient directly. Therefore, needed data including streams information (fluid flow, physical properties, supply and target temperature), exchangers data (exchangers geometry, type of streams, shell and tube properties) and economic information cost of energy consumption (energy cost) and cost of heat exchangers installation (capital cost) should be carefully extracted and assembled. In Table 1, the necessary extracted information and a sample network is represented. In this research, Aspen pinch software has been used [5].

Tmax

Tmax

H

Composite curves (CC)

Tmax QHmin

QHmin

QCmin

Shifted composite curves

H

QCmin

H

Grand composite curves (GCC)

Fig. 1 Tools for pinch analysis: composite curve (CC) and grand composite curve (GCC). Table 1 Extracted data. Stream name HOT 1 HOT 2 HOT 3 HOT 4 HOT 5 HOT 6 COLD 1 COLD 2 COLD 3 COLD 4

TSupply (°C) 85 120 125 56 90 225 40 55 65 10

TTargrt (°C) 45 40 35 46 85 75 55 65 165 170

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Duty (MW) 6.25 4 2.15 12.5 7.5 7.5 7 6 19.5 13

MCP (kW/°C) 156.25 50 23.89 1250 1500 50 466.57 600 195 81.65

HTC (kW/M2K) 1.58 1.11 1.56 1.02 1.48 1.98 0.63 0.57 0.97 0.78

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A Survey on a Heat Exchangers Network to Decrease Energy Consumption by Using Pinch Technology Table 2 Economical data.

2.2 Economical Data Correct economic data including operation time, interest rate and equipment life have an important role on successful execution of retrofit and preparation. The values are shown in Table 2. The condition of utilities which includes steam and cooling water is shown in Table 3 [6]. Capital cost and energy cost of network can be calculated with respect to the shells number and the cost of any exchanger calculates with using Eq. (1): Capital Cost = a+b(Area)c (1) In this equation, a, b and c are constant. So that, “a” is function of pressure intensity, “b” is function of exchanger material and “c” is function of type of exchanger that is different for various exchangers; so 0 < c < 1. Types of exchanger are defined by designer based on nature of chemical materials, pressure of flows, pressure condition and ability of corrosion. For carbon-still exchanger, cost equation is as follow: Capital Cost = 30800 +750 (Area) 0.81 (2) 2.3 Total Annual Cost Plot Increasing ∆Tmin, the energy cost and decreasing the capital cost, therefore, the trade between these two characters is necessary [1]. Fig. 2 shows the total

Description Operating time per year (h) Equipment life (years) Interest rate (%)

Quantity 8,000 3 10

Table 3 Utility condition data. Utility Cooling water HP steam

Tin (°C) 20 200

Tout (°C) 25 1208

annual cost for shell and tube exchanges (A1-2) regarding to ∆Tmin. According to Fig. 2, 10 °C is obtained as optimum ∆Tmin for A1-2 exchangers. In this stage, minimum area-energy plot has been drawn. This curve shows the minimum energy and area of a design at different ∆Tmin. At retrofit design, area efficiency is very important. Two concepts of constant and incremental efficiency are used in retrofit design. Often, for α > 0.9 constant method is used and for α < 0.9 second method is used. Fig. 3 shows the area-energy consumption curve for existing process. Area efficiency was 0.95. Because the area efficiency (α) is more than 0.9, therefore, α-constant plot has been used. Optimum ∆Tmin will be different for different amount of investment and payback of investment.

Total Cost

Area Cost

Cost (C)

Price (US$/kW.h) 0.00034 0.01672

C-2.24 T-10.0

C-2.27 T-10.0 Energy Cost C-0.15 T-10.0

Fig. 2 Range target plot of total annualized cost (A1-2) showing the optimum Min Delta T (ΔTmin).


Area (m2)

Thus, change of retrofit condition is necessary; hence, investment and energy saving increases. However, this is contrary to retrofit limitation because network retrofit should be done with minimum investment if it is possible. Thus, although decrease of cold and hot utility consumption at low ∆Tmin is possible, the results of consumption optimization of utility from a pinch principle point of view are acceptable. Therefore, in retrofit design, 10 °C is

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obtained as an optimum ∆Tmin. Fig. 4 shows the composite curve (CC) of process with optimum ∆Tmin.

3. Analysis of Heat Exchangers Network Analysis of available exchanger is the first stage for heat exchangers network (HEN) design, at retrofit conditions. Since the energy saving potential at retrofit project fixes at targeting stage, the available network has been studied by pinch technology point of view.

αExist

αTarget

QH (× 103 kW)

Temp. (°C)

Fig. 3 The area-energy consumption curve for existing network.

Ηοτ

Entalpy (× 10 kW) Fig. 4 Composite curves (CC) temperature vs. enthalpy of existing process.

COLO

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Fig. 5 shows the grid diagram of exchangers network at ∆Tmin = 10 °C. Fig. 6 shows the driving force plot. Grid diagram shows that neither of exchangers passes from pinch point. In pinch retrofit method, at targeting stage, ∆Tmin is defined as a saving fixer (specify) factor and optimum value of ∆Tmin is obtained about 10 °C and minimum process energy usage is obtained from composite curve. At energy recovery from network, confront to the bottlenecks limit of the work is possible. To remove these problems at diagnosis stage some plants are considered. Therefore, with increasing of the energy saving, heat shifts are from above the pinch to below the pinch. These changes include re-sequencing, re-piping, add heat exchangers and splitting. Diagnosis Stage: We use this method at this stage to show firstly re-sequencing, then re-piping and finally adding heat exchangers. If any of cases were not suitable and did not reply, try the splitting, and at the end (finally) best case obtain chose. For start, ∆Tmin is needed. From area efficiency method, 10 °C is obtained as an optimum ∆Tmin. Table 4 shows the results related to re-piping obtained from Aspen Pinch software. Minimum heat demand is minimum energy usage in

Fig. 5 Grid diagram of existing HEN of unit.

network with respect to applying the proposed changes, but its surface does not change. Heat demand reduction is the amount of energy reduction that is obtained with applying retrofit changes. If this value is positive, saving is accessible and for negative value, those changes do not occur.

4. Results and Discussion Study of different cases at diagnosis state shows that heat demand reduction value has much in significant positive or negative value. It shows that this network has a low potential of retrofit to decrease the energy consumption. In order to implement retrofit design on heat system, the exact changes and installation of new heat exchanges and new investment in that system are needed; therefore, regarding to the results of pinch analysis, it is suggested that in order to reduce the energy consumption no alternation in the unit heat exchangers network does not make any sense. To decrease energy consumption, the other parameters of unit can be studied and with distinguish the irreversible reason represents methods for reducing the energy consumption. Table 5 shows the results of heat exchangers network.

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Delta Tc


TCold (°C) Fig. 6 Driving force plot. Table 4 The results related to re-piping. Heat exchanger ID

Hot stream location

Cold stream location

Minimum heat demanded (kW)

Heat demanded reduction (kW)

HX-X021

End of HOT 6

Up-Stream of HX-X021 on COLD 4

15,459.25246

-63.83579499

Table 5 Final results. Description Total number of exchangers Total area Total purchased cost Total installed cost Total hot energy consumption Total hot energy cost Total cold energy consumption Total cold energy cost Annualized capital cost Annualized energy cost Total annualized cost

Quantity 20 5,020.7 563,286.76 563,286.76 15,395.4 2,059,228.26 9,795.4 26,738.68 187,762.25 2,085,966.93 2,273,729.19

Unit m2 US$ US$ kW US$/y kW US$/y US$/y US$/y US$/y

5. Conclusions In this paper, the application of pinch technology in analysis of a heat exchangers network (HEN) in order to reduce the energy consumption in a thermal system has been studied. The case study has 6 hot streams and 4 cold streams which transfer energy by using a heat exchangers network. In this case the optimum value of ∆Tmin is obtained about 10 °C and area efficiency (α) is 0.95. In order to increase the amount of energy saving, heat transfer from above to below the pinch point in the diagnosis stage is verified for all options including

re-sequencing, re-piping, add heat exchanger and splitting of the flows. By analyzing the results, it is obvious that the network has a low potential of retrofit to decrease the energy consumption, which means pinch principles is effective regarding to the unit. Thus, it is suggested that in order to reduce the energy consumption no alternations in the heat exchangers network of the unit does not make any sense.

References [1] [2] [3]

[4]

[5] [6]

T. Umeda, J. Itoh, K. Shiroko, Heat exchanger system synthesis, Chem. Eng. Prog. 74 (1978) 70-76. B. Linnhoff, J.R. Flower, Synthesis of heat exchangers network, AIChE Journal 24 (1978) 633. A.I.A. Salama, Numerical construction of HEN composite curves and their attributes, Computers and Chemical Engineering 33 (2009) 181-190. M. Gorjy Bandpy, H. Yahyazadeh Jelodar, M. Khalili, Optimization of heat exchanger network, Applied Thermal Engineering 31 (2011) 779-784. Aspen Engineering Suite 11.1, Aspen Technology, Inc., MA 02141-2201, Cambridge, USA, 2001. B.A. Al-Riyami, J. Klemes, S. Perry, Heat integration retrofit analysis of a heat exchanger network of a fluid catalytic cracking plant, Applied Thermal Engineering 21 (2001) 1449-1487.

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DAVID

PUBLISHING

Implementation of Cooling Systems to Enhance Dairy Cows’ Microenvironment M. Samer Department of Agricultural Engineering, Faculty of Agriculture, Cairo University, Giza 12613, Egypt Received: April 11, 2011 / Accepted: May 23, 2011 / Published: December 20, 2011. Abstract: A tool was developed to assist the cooling systems designer in designing and installing the microsprinklers and fan cooling system. The tool was developed by integrating a mathematical model into an electronic spark map in order to use the mathematical model practically. The mathematical model was developed using the designs, parameters, variables, and constant values of the microsprinklers and fans cooling system. Subsequently, an electronic spark map (decision tree) was developed, and then the mathematical model was integrated into the electronic spark map. Afterwards, C# (C Sharp) programming language was used to develop a computer system via the electronic spark map, and to make the user interface. The developed computer system assists the designer in making decisions to specify and to calculate the required discharge of cooling system pump, length and diameter of cooling system pipelines, number of cooling fans, and number of microsprinklers. Moreover, this tool calculates the capital investment and the fixed, variable, and total costs of the cooling system. However, the mathematical model of the spark map requires some input data such as: pressure and discharge of microsprinklers, and some other engineering parameters. Data of 4 cooling systems were used to carry out the model validation. The differences between actual and calculated values were determined, and the standard deviations were calculated. The coefficients of variation were between 2.25% and 4.13%. Key words: Cooling system, microenvironment, computer system, mathematical modeling, precision livestock farming, microsprinkler.

1. Introduction Comfort range for dairy cows is between 4.5 and 21 C (40 and 70 oF). Cows are usually not adversely affected by the cold until the temperature drops to -15 o C (5 oF); below this temperature a drop in milk production occurs [1]. Heat stress in dairy cattle is one of the leading causes of decreased production and fertility. Thus, dairy cattle need mechanical means to reduce heat stress. When temperature is between 5 and 15 oC the cows are most productive, and when the temperature is between 15 and 25 oC a small degree loss in production occurs, when the temperature exceeds the upper critical temperature (25 oC) a great degree loss in production occurs. If the body temperature increases from 38.8 oC to 39.9 oC a drop of 2.2 kg/day o

in milk production occurs. The way to estimate heat stress is computing the temperature humidity index (THI): THI = (0.81 × dry bulb temp. oC) + [RH% × (dry bulb temp. oC-14.4)] + 46 If THI less than 72 there is no stress, between 73 and 77 there is a mild stress, between 78 and 88 there is a significant stress, between 89 and 99 there is a severe stress, if THI exceeds 99 a possible death occurs [2]. Skin and rectal temperature and respiration rate increase with the increasing of the temperature. For these reasons the installation of an efficient cooling system is required. They added that cooling system efficiency increases by increasing cowshed height [3-6]. 1.1 Sprinkler and Fan Cooling Principles

Corresponding author: M. Samer, assistant professor, Ph.D., main research field: animal housing and environmental control. E-mail: [email protected].

The sprinklers create droplets that wet the cows’

Implementation of Cooling Systems to Enhance Dairy Cows’ Microenvironment

hair coat to the skin. Fans are then used to force air over the cows’ body (Fig. 1), causing evaporative cooling to take place on the skin and hair coat. Heat from the cows’ body causes the moisture to evaporate [7, 8]. 1.2 Planning and Components Selection There are some general design guidelines which must be followed in locating the system, selecting the nozzles and the fans, and ensuring a good water supply [8]. 1.3 Locating the System For best results system should be located under shade. A shaded feed bunk (Fig. 1) or the holding pens (Fig. 2) are the two locations currently recommended. Because of some concern over possible mastitis problems, location of a sprinkler system in a freestall barn may not be desirable, particularly if straw, sawdust or other absorbent bedding is used [8].

Fig. 1

Sprinklers and fans cooling system [8].

Fig. 2

The holding pen [8].

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1.4 Selecting the Nozzles A size range of 0.45 to 1.89 liter/min (0.12 to 0.5 gpm) per nozzle is preferred to conserve water, reduce the total required flow rate and avoid runoff problems. Either 180o (half-circle) or 360o (full-circle) nozzles may be used. The 180o nozzles work well mounted next to a feed bunk, spraying away from the feed to help avoid wetting it (Fig. 3). The 360o nozzles work well in a holding area, sprinklers system needs to be suspended 1.5 m (5 ft) behind the feed line and spray diameter limited to (8 ft) 2.4 m [8, 9]. The recommended nozzle pressure for most spray jets and microsprinklers is 138 to 172 kPa (20 to 25 psi). If the operating pressure is too high, the droplet size will be reduced and the resulting mist will drift. Also, the smaller droplet will not penetrate through the animal’s hair coat to the skin, and much less cooling will occur. Thus, pressure regulator should be installed to limit the required nozzle pressure to these recommended values [8].

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(a)

Fig. 3

Fig. 4

Typical sprinkler located over feed line [9]: (a)

(b) side view; (b) top view.

Cooling system components [9].

A thermostat should be set to turn the sprinkler on when the air temperature exceeds 21 to 24 oC (70 to 75 oF). The thermostat will control a valve or solenoid located prior to the first nozzle, the solenoid valve controls the water flow through the pipe [1]. Fig. 4 shows the cooling system components.

used and has the following specifications: fan power of 0.5 horse power, and diameter of 91.5 cm (36 inches) fans. Such fans will blow about 16990 to 18689 m3/h (10000 to 11000 cfm) with a “throw” distance of about 9.2 m (30 ft). A 1 hp 122 cm (48 inches) fan will provide 35679 m3/h (21000 cfm) with an effective throw distance of 12.2 m (40 ft). These fans should be mounted out of reach of the cows and angled downward slightly. Overhead paddle fans can also be used to provide airflow, but they offer limited air movement unless cows are directly under a fan. The paddle fans do have much higher efficiencies of operation, with range of 170 m3/h (100 cfm) per Watt of power input [8].

1.5 Selecting Fans Air movement in the velocity range of 1 to 2 m/s (200 ft to 400 ft per minute) across the cows is needed. Fan/tube systems have been successfully used; they should be sized to provide 255 to 425 m3/h (150 to 250 cfm) of air flow per cow. For tubes mounted high above the cows, a flow rate of 680 m3/h (400 cfm) may be needed per cow. In holding pens or other areas with higher eave heights, another type of fans is often

1.6 Objective The objective of this paper is to develop a tool that assists in designing and installing the microsprinklers and fans cooling system.

2. Methods and Data The tool was developed by integrating a mathematical model into an electronic spark map


(decision tree) developed in MS-Excel. The mathematical model was developed using the plans, designs, parameters, variables, and constant values of microsprinklers and fans cooling systems available in the references. Subsequently, MS-Excel was used to develop the electronic spark map (Fig. 5) of the mathematical model, and then C# (C Sharp) programming language was used to develop a computer system using the spark map, and to make the user interface. The validation of the mathematical model was carried out using data of 4 cooling systems. The relative differences between actual values and

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calculated values were determined, and then the averages of relative differences were computed. Afterwards, the standard deviations (σ) and the coefficients of variation (COV) were determined. This methodology agrees with that developed by Samer et al. [10]. Mathematical Modeling: The objective of making cooling system design model (CSM) is to design the cooling system and to decide some parameters, such as: discharge and pressure of the microsprinklers and the pump. Moreover, CSM determines the dimensions of the main line, sub-main line, and pipe lines. Also, CSM calculates the capital investment and the fixed, variable, and total costs. 2.1 Cooling Fans The preferred specifications of the cooling fans are: diameter 90 cm, ½ hp, 825 rpm, and 60 Hz. The required number of cooling fans is dependent on the cooling line length. Thus, NtCF =

Fig. 5 model. Table 1 Symbol LCO QMS PrMS NCLC tCS SCF PCF PCP PCPL LCML PCML LCSL PCSL SM CECS PM PA PPG PtVF NCT PCT PFC CVCS

Electronic spark map of cooling system design

LCO × NCLC SCF

(1)

Where, the variables were defined in Tables 1 and 2. Input data. Description Cooling line length Microsprinkler discharge Microsprinkler pressure Number of cooling lines for one cowshed Cooling system lifetime Span or distance between 2 cooling fans Price of cooling fan Price of cooling system pump Price of 1 m of cooling system pipe line Length of cooling system main line Price of 1 m of cooling system main line Length of cooling system sub-main line Price of 1 m of cooling system sub-main line Span or distance between 2 microsprinklers Employment costs of cooling system Price one microsprinkler Price of anemometer Price of pressure gauge Total price of valves and fittings Number of required taps for cooling system Price of one cooling system tap Price of cooling system filter Variable costs of cooling system

Unit m L/min kPa Year m Currency Currency Currency/m m Currency/m m Currency/m m Currency Currency/Microsprinkler Currency Currency Currency Currency/Tap Currency Currency/Year

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Table 2 Output data. Symbol NtCF PtCF QCP PrCP LtCP dCP PtCP PtCL PtCS NM PtM PtCT CICS CFCS CTCS

Description Total number of cooling fans Total price of cooling fans Discharge of cooling system pump Pressure of cooling system pump Total length of cooling system pipe lines Diameter of cooling system pipe line Total price of cooling system pipe lines Total price of cooling system main line Total price of cooling system sub-main line Number of microsprinklers Total price of microsprinklers Total price of cooling system taps Capital investment of cooling system Fixed costs of cooling system Total costs of cooling system

The cooling line consists of microsprinklers, fans, and pipe line(s). However, the number of cooling lines for one cowshed is depending on the design type, i.e. if two sides of corrals are required then two cooling lines should be installed, but if one side of corrals is under consideration then one cooling line should be installed. In general, the fans should be spaced by 6 m and the cooling system lifetime is about 10 years. 2.2 Cooling System Pump

Unit Currency m3/h kPa m mm Currency Currency Currency Currency Currency Currency Currency/Year Currency/Year

nearest the required design discharge should be chosen. However, the discharge and the pressure of the pump will be calculated as: QMS × N M × 60 1000

(2)

PrMS × 105 LCO × N CLC × PrMS × 10 + 100 100 × 100

(3)

QCP =

PrCP =

where LCO = LH NM =

Some instructions should be considered while selecting the pump, which are: Ÿ Pressure difference between the first micro-sprinkler and the last one in the pipe line is about 5%; Ÿ For 100 m length of pipe line, the pump should have additional pressure by about 10% of the micro-sprinkler’s pressure; Ÿ Sometimes it is impossible to find the exact pressure in the market; thus the greater pressure nearest the required design pressure should be chosen; Ÿ The required discharge and pressure of the pump should be compared to tables of pumps technical data, in order to choose a pump which has a determined pressure and a range of discharges; Ÿ Sometimes it is impossible to find the exact discharge in the market; thus the greater discharge

LCO × NCLC SM

QMS = 0.42

PrMS = 176

(4) (5) (6) (7)

2.3 Cooling System Water Lines The cooling system water lines are: main line, sub-main line, and pipe line(s). Usually, the main line is made from PVC, with standard length of 6 m, and diameter of 38.1 mm (1.5 inches). However, the sub-main line is made from PVC, with standard length of 6 m, and diameter of 25.4 mm (1 inch). The pipe line(s) should be flexible and made of PVC. However, the total length of the pipe lines is calculated as: LtCP = N CLC × LCO (8) When specifying the diameter of the pipe line(s), some design parameters should be considered: Ÿ For laminar flow, V = 1.5 - 2.0 m/s, but to be


secure it is better to substitute it as 1 m/s in the equations. y Sometimes it is impossible to find the exact diameter in the market; thus, the near greater diameter than the required diameter should be chosen. y The available standard diameters are: 11, 16, 18, 20, and 32 mm which are made from PE; and 40, 50, 63, 75, 90, 100, 110, and 125 mm which are made from UPVC or from PVC. However, the pipe line diameter is calculated as: d CP =

4 × QCP × 10 6 π × 1 × 3600

(9)

Usually, 2 taps 50.8 mm Ø (2 inches Ø) are required, and a filter of 100 meshes should be installed. 2.4 Costs Calculation The costs of the different parts of the cooling system are calculated as: PtCF = N tCF × PCF PtM = N M × PM

PtCT = N CT × PCT PtCP = PCPL × LtCP PtCL = PCML × LCML

PtCS = PCSL × LCSL

(10) (11) (12) (13) (14) (15)

CICS = PtCF + PCP + PtCP + PtCL + PtCS + CECS + PtM + PA + PPG + PtVF + PtCT + PFC

(16)

CICS tCS

(17)

CFCS =

CTCS = C FCS + CVCS

(18)

3. Results and Discussion 3.1 Spark Mapping The electronic spark map (Fig. 5), of designing cooling systems, specifies and calculates the required discharge of cooling system pump, length and diameter of cooling system pipelines, number of cooling fans, and number of microsprinklers. Moreover, this tool calculates the capital investment and the fixed, variable, and total costs of the cooling system. However, the mathematical model of the spark map requires some

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input data (Table 1), such as: pressure and discharge of microsprinklers, and some other engineering parameters. According to these data, the electronic spark map will compute the output data (Table 2) by using the mathematical model. On the other hand, the spark map is empowered by a range of values for each required input data in order to help the designer in deciding and selecting the required values. 3.2 Model Validation Data of 4 cooling systems were used to perform the model validation and the spark map evaluation. The cooling systems were located in different dairy farms in Egypt. Systems 1 and 3 were old systems, but systems 2 and 4 (Table 3) were recently installed. In addition, all systems were installed next to feed bunks. The data of the cooling systems used in the validation were considered as actual values and were divided into two categories. The first one is used just as input data (Table 1) that should be inserted into the spark map. The second category is considered as output data (Table 2) that should be compared to the output data calculated by the spark map. The differences between calculated and actual values were determined, and then the averages differences were computed. The statistical analysis of the actual and calculated values (Table 3) elucidated that COV were between 2.25% (σ = 0.23) and 4.13% (σ = 0.13). 3.3 Input Data Window The cooling system sub-model requires some input data (Fig. 6), such as: cooling line length which is equal to house length, and number of cooling lines for one cowshed which is dependent on corrals distribution. Furthermore, values of some input data will be recommended by the system e.g. the values of micro-sprinkler discharge and pressure. The other input data are the prices of the cooling system components which should be acquired from market prices.

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Table 3 Model validation. System 1 System 2 System 3 System 4

Fig. 6

Parameter Actual value Calculated value Actual value Calculated value Actual value Calculated value Actual value Calculated value

NtCF 37 37 36 36 4 4 10 10

QCP 1 0.9 1 0.9 0.27 0.24

PrCP 230 223 230 222 200 194

LtCP 224 224 180 180 57.6 57.6

dCP 18 18 18 18 11 11

NM 37 37 36 36 10 10

Input data window of cooling system sub-model.

3.4 Output Data Window Subsequent to filling the input data boxes and clicking the button of “Calculate”, the system calculates and displays the output data (Fig. 7) which are the design parameters and the costs. 3.5 Safety Emphasis In contrast to traditional methods therewith making mistakes is possible, using this electronic spark map diminish the possibility of making mistakes when designing cooling systems, hence improving safety. Hence, this paper provides a new tool for designing cooling systems, and using a preset tool which enhances the safety measures. On the other hand, this tool is validated using

actual

assure high safety levels and to errors.

data in order to uproot system Fig. 7

Output data window of cooling system sub-model.


4. Conclusions The developed computer system can be used practically in designing cooling systems, computing the discharge and the pressure of cooling system pump, specifying the dimensions of the different cooling lines, and calculating the costs. The methodology developed in this paper represents a new approach for developing computer systems by using the mathematical models for practical implementation. Furthermore, integrating the mathematical model into a specially customized electronic spark map to form the heuristic and the back diagram code of a computer system represents a new approach. Further research can be carried out, using similar methodology, to develop computer systems that are able to plan and design several dairy farm facilities (forage storage, manure storage, etc.).

References [1]

[2]

G.H. Schmidit, V. Vleck, L.D.M.F. Hutjens, Dairy cattle housing, in: Principles of Dairy Science, 2nd ed., Prentice Hall, USA, 1988, pp. 428-444. J.F. Keown, R.J. Grant, How to reduce heat stress in dairy cattle, Technical Report, University of Missouri-Columbia, USA, 1999.

[3]

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M. Samer, Engineering parameters affecting dairy cows microclimate and their productivity under Egyptian conditions, M.Sc. Thesis, Cairo University, 2004, p. 176 . [4] M.H. Hatem, R.R. Sadek, M. Samer, Shed height effect on dairy cows microclimate, Misr J. Ag. Eng. 21 (2004) 289-304. [5] M.H. Hatem, R.R. Sadek, M. Samer, Cooling, shed height and shed orientation affecting dairy cows’ microclimate, Misr J. Ag. Eng. 21 (2004) 714-726. [6] M.H. Hatem, R.R. Sadek, M. Samer, Effects of shed height and orientation on dairy cows microclimate, cooling system efficiency and milk productivity, in: 16th CIGR International Conference on Agricultural Engineering, Bonn, Germany, 2006. [7] M.J. Meyer, J.F. Smith, J.P. Harner, J.E. Shirley, E.C. Titgemeyer, M.J. Brouk, Performance of lactating dairy cattle in three different cooling systems, Applied Eng. Agric. 18 (2002) 341-345. [8] L.W. Turner, R.C. Warner, J.P. Chastain, Micro-sprinkler and fan cooling for dairy cows: Practical design considerations, Technical Report, University of Kentucky, Extension Service, USA, 1997. [9] J.P. Harner, J.F. Smith, M. Brook, J.P. Murphy, Sprinkler systems for dairy cows at a lane feeding, Technical Report, Kansas State University, Extension Service, USA, 1999. [10] M. Samer, An expert system for planning and designing dairy farms in hot climates, Ph.D. Thesis, University of Hohenheim, Stuttgart, Germany, 2008, p. 161.


D DAVID

PUBLISHING

Ergonomic Aspects of Operation of IT Systems in Precision Agriculture T. Juliszewski and M. Walczykova Institute of Machinery Management, Ergonomics and Production Processes, Faculty of Production and Power Engineering, University of Agriculture, Krakow 12, Poland Received: April 13, 2011 / Accepted: June 14, 2011 / Published: December 20, 2011. Abstract: The operation of IT systems is a sine qua non condition in precision agriculture. In the traditional approach, professional competencies of a farmer comprise the ability to operate machines and technical equipment in production technologies for biological raw materials. Precision agriculture increases this range of professional competencies with the ability to use computer IT systems that are complex and, by their very nature, much differing in their content and scope from typical farming knowledge. The ergonomic problem can be brought down to determination whether the operation of IT systems in precision agriculture is adjusted to the predispositions, needs and skills of the farmers. Generally, in the IT system of precision agriculture, three phases can be differentiated: data collection, processing and application. To what extent should they be operated by the farmer, and to what extent by the IT specialist, is the problem that determines effective functioning of precision farming. The ergonomic assessment of some software for equipment operation, generation of harvesting maps and applications points to: (1) the need for standardisation in construction and operation of IT systems; (2) the division of the function—farmer and IT specialist (e.g. from an agriculture consulting institution) in the precision agriculture system. Key words: Operating specialist hardware and software, ergonomic assessment, need for standardisation.

1. Introduction Precision agriculture functions as a result of linking the (1) agro-technical and (2) IT knowledge. The intended effects of precision agriculture, such as reduced production costs, qualitative and quantitative levelling of harvest, reduction of environmental threats via local application of plant protection agents, require the ability to (a) harvest, (b) process, (c) apply the data in various IT systems. Such systems are placed on tractors, combines for harvesting, machines for application of fertilisers or chemical plant protection agents. Furthermore, input data characterising spatial differentiation of (a) harvest and (b) soil are processed in specialist software into output data to control the operation of e.g. machines differentiating rates of the fertiliser. Traditional Corresponding author: T. Juliszewski, professor, Ph.D., main research fields: agricultural engineering, ergonomics. E-mail: [email protected].

professional competencies of a farmer, namely the ability to operate machines and technical equipment in technologies for production of raw materials of biological origin (plants and animals), must be, therefore, extended by the abilities to operate IT systems used in such technologies [1].

2. Two Methods for Farm Management In many regions of the world, also in the European conditions, business activity in agriculture is usually managed with one of the following methods: (1) all works, or their majority, are performed in the farm with tractors and machines owned by the farmer, (2) almost all works are performed using outsourced tractors and machines. The earlier method principally refers to so-called family farms, or large farms owned by e.g. the State Treasury, as it is the situation in the country of the authors of this article. Plant production is usually joined here with animal production. The

Ergonomic Aspects of Operation of IT Systems in Precision Agriculture

other method refers to farms where the owner (or leaseholder) usually deals with plant production without directly participating in such production, by outsourcing the field works from specialist companies. There is no clear border between the two methods. We differentiate them to draw attention to two types of users of tractors and machines applied in precision agriculture: (1) In a family farm, a farmer should individually operate IT systems, at least for data collection and their later application (after processing); (2) In a farm operating in the outsourcing system, the operation of precision agriculture IT systems can also be outsourced, just as the performance of agro-technical works. Specialisation of outsourcing companies causes that the problems with operation of precision agriculture IT systems, namely collection, processing, and application of data, can be simply solved by hiring specialists. At a family farm, the operation of IT system for agriculture is a new professional competence of a farmer to be at least partially learnt.

3. Operation of Hardware and Software The fundamental aspect of ergonomic assessment of operation of electronic devices and utility software regards compatibility [2]. The term “compatibility” is presently used principally in reference to computer

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technology and generally means the possibility of effective information flow between the transmitter (one computer) and the receiver (another computer or a peripheral device, such as a printer). In fact, this information flow is ensured by a clear code in which the information is saved and sent between the elements of the system. Let us draw the attention, however, to the fact that in the operation of IT systems, there is always also a human being (the operator) and the problem of compatibility also refers to this element of the IT system (namely, the operator). A system cannot be referred to as “compatible” if the operator is not considered, as he is the main user of the information. Information transmitted with the agreed code (signals) should be clearly interpreted (decrypted) both by electronic devices and (understood) by the system operator. It is necessary to differentiate the operation of electronic devices (e.g. on-board computers in tractors and machines), as on Figs. 1 and 2 and the operation of specialist software for data processing (e.g. Agro-Map) as on Fig. 3. The operation must take into account the following fundamental ergonomic recommendation: elements of the system, distributed in various places, must be operated in the same manner (namely according to the same sequence of control actions for the same functions). Let us also add to this recommendation IMO ACT

Fig. 1

Control panel of an on-board computer for harvest registration in the Claas Lexion 480 combine.

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LH 5000 GPS PDA

+

SiteMate

software

Fig. 2

Control panel for computer to control the operation of the fertiliser distributor.

Fig. 3

Example of Agro-Map data processing software by Agrocom.

that learning to operate compatible systems, namely considering human mental predisposition, is easier, and the risk of making a mistake is lower. Naturally, for elderly operators this is of special importance. Operation of electronic devices is, in fact, a strictly defined sequence of control activities, usually comprising the pressing of one or more keys on a keyboard or symbols on a touchscreen. The number of

functions of an on-board computer varies, and so does the number of control actions to launch such functions. And so, the first use of the Claas type combine with optical harvest registration by Agrocom, at the beginning of the season, will require the performance of at least 15 functions — together on on-board computers of the system and the combine (Fig. 1), comprising 47actions (Table 1). The aforementioned


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Table 1 The number of functions and actions related to operation of an on-board ACT computer cooperating with on-board IMO computer of the combine, during harvest registration with optical monitoring system by Agrocom. Functions usually performed once per season No. of Number of func. Type actions

No.of func.

1

Setting the date and time

4

1

2 3

Language selection Resetting of combine slant sensor Setting the zero point for harvest measurement Calibration of speedometer

4 5

2 3

Functions related exclusively to the harvest registration Number of Type actions Entrance of a chip card with the request to the 1 computer Checking the correctness of GPS status 2 Selection of the request to process 2

5

4

Starting the request (start)

5

5 6 7 8

4 5 6 7 8 9

10 Total number of functions 5 Total number of actions 23 Number of functions for operation of an exemplary set 15 Number of actions for operation of an exemplary set 47

1

Input of data on volume weight 3 Switching to the harvest parameter screen 1 Adjustment of humidity during operation 3 Adjustment of volume weight during operation 3 Value adjustment on the collected harvest weight 9 5 during operation 10 Closure after the completion of the request 3 Total number of functions 10 Total number of actions 24

two computers are “functionally connected”, and presently the company begins to replace this configuration with a single device. In the case of controlling a variable application for mineral fertilisers, the situation may be as presented in Table 2, where the number of actions reaches 58. In the case of using the same machine, the encoding of parameters will not be necessary, and then the number will drop down by 36 (9 × 4) (Table 2). Let us draw attention here, apart from differences in the appearance of the on-board computers and their operating procedures, to the specificity of using agricultural machines, namely: (1) relative short operating time during the year (seasonal, sometimes just 100-200 hours per year); (2) need to operate various machines (and on-board computers) by the same operator [3, 4]. During data collection about the harvest and its moisture, with the frequency of－0.2 Hz for harvest (one measurement per 5 s), moisture－up to 20 s per measurement depending on the size of the harvest, at a field of 20 ha, approximately 4500 numbers are collected (considering only yield data). These will later allow for development of application maps －

unless the operator has made a mistake while launching the harvest registration system. Let us draw the attention to the fact that both data collection in the on-board computers of the combines (tractors), and the use of application maps for fertilisation or herbicide dosing, occurs without (visual) control of the user (driver) who is convinced that the electronically controlled system functions correctly. The requirement for control cannot be, by its nature, formulated against the operator, as this clearly exceeds the capabilities of his visual perception (e.g. the observation of the variable dose of the fertiliser or herbicide). The only requirement to be formulated is that the procedures for on-board computer operation be performed correctly (faultlessly). The operation of software for processing of the data characterising the harvest and soil at the field requires specialist knowledge and skills. It also, certainly, requires having a costly computer software. The basic menu of Agro-Map software, which forms an integral part of the monitoring system described in this article, comprises 6 tabs (Fig. 3) with a varied number of functions, the more complex of which require several actions to achieve the intended goal. The performance


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Table 2 The number of functions and actions related to the performance of spatially varied fertilisation using the system: on-board computer LH 5000 GPS + PDA with SiteMate VRA software. LH 5000 GPS

PDA with SiteMate VRA software

No. of Functions func. 1 action 2 Selection of machine 3 model

Number of actions 2 2 2

No. of func. 1 2 3

4

Operating width

4

4

5

Selection of fertiliser dose

4

5

6

Selection of speed sensor

4

6

7

Operating field area

4

7

Quantity of fertiliser in the tank

4

Selection of operating time sensor

4

10

Selection of passage length sensor

4

11

Setting PTO shaft sensor (once per season)

4

12

Setting possible (optional)

4

8 9

Encoding machine parameters

percentage

dose

Functions

Number actions

Launch of the SM software VRA selection Display of application map

2 1 1

of

Selection of dosing parameter 1 (optional) Selection of file name for 1 background save (optional) Setting the operating 9 parameters Start 1

change

Total number of functions Total number of actions Number of functions for operation of an exemplary set 19 Number of actions for operation of an exemplary set 58

of application maps for fertilisation, starting from development of harvest map, through creation of the plan for soil sampling for richness, performance of richness maps and the maps for fertiliser demand－ this requires, by estimate, over 100 actions.

4. Conclusion The operation of the entire IT system in precision agriculture－from data collection, via data processing, to practical application － exceeds traditional competencies of a farmer. There is, however, rationale for acquiring such skills. The operation of the entire IT system must meet the following ergonomic requirements: (1) Control panels and the procedures for operation of such control panels occurring in various parts of the IT system (in various machines)

12 42

Total number of functions Total number of actions

7 16

must be similar to one another as much as possible; (2) Operating procedures should be simplified so that the most important functions (“Record data”, “Save data”, “Apply data from file”, etc.) can be launched with one button on the control panel (particularly important for elderly farmers); (3) Standardisation of procedures for data transfer from the farmer to the company processing such data－and the other way round－ would facilitate their mutual cooperation. The fact that manufacturers of electronic equipment for tractors, combines and farming machines used in precision agriculture keep forgetting about ergonomic adjustment of those devices to operator needs is one of the reasons limiting the industry development. According to the survey performed in Germany regarding the perspectives for application of precision


agriculture in their country, among the greatest difficulties, most respondents included “the need of long time to learn equipment operation”, “lack of compatibility”, and “unreliable software” [5].

[4]

References [1]

[2]

[3]

H. Göhlich, Man and Machine, Textbook of Agricultural Engineering, Paul Parey Publishing House, Hamburg and Berlin, 1987, pp. 72-83. C.G. Hoyos, Compatibility (in: Ergonomics 2), Organization of Work Place and Work Environment, Carl Hanser Publishing House, Munich, 1974, pp. 93-112. T. Juliszewski, Compatibility of signalling equipment in tractors and farming machines, in: Proceedings CIGR VI

[5]

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World Congress, Bonn, 2006, pp. 266-368. T. Juliszewski, Ergonomics related problems of compatibility of signalling devices of tractors and farm machinery, in: XXXIII CIOSTA CIGR V Conference 2009 － Technology and Management to Ensure Sustainable Agriculture, Agro Systems, Forestry and Safety, Workshop IUFRO–Forestry Utilization in Mediterranean Countries with Particularly Respect to Sloping Areas, Vol. 2, Reggio Calabria, Italy, June 17-19, 2009, pp. 1523-1527. M. Reichardt, C. Jürgens, Adoption and Perspective of Precision Farming (PF) in Germany: Results of Several Surveys among the Different Agricultural Target Groups, Wageningen Academic Publishers, 2007, pp. 843-850.


D DAVID

PUBLISHING

Effect of Bentonite on the Sandy Soils of Arid Regions: Study of Behavior of an Association of Wheat and Chickpea H.Y. Reguieg1, M. Belkhodja2 and A. Chibani1 1. Laboratory of Biology, Faculty of Science, University of Mostaganem, Mostaganem 27000, Algeria 2. Laboratory of Plant Physiology, Faculty of Science, University of Oran Senia, Oran 31000, Algeria Received: November 1, 2010 / Accepted: June 8, 2011 / Published: December 20, 2011. Abstract: The sandy soils of Mostaganem plateau are very poor in clay. They are characterized by very low fertility and water holding capacity. The addition of bentonite to these soils and the cultivation of durum wheat, in combination with the chickpeas, are two eco-physiological strategies to rehabilitate their agricultural suitability. This study was conducted on two plant species: a local variety of durum wheat (Waha) and a legume, chickpea (variety ILC 3279), on a substrate bentonite at 10% dose. For each stage of growth measurements of stem height, leaf area and plants vegetative nitrogen content were quantified. Changes in total nitrogen content of durum wheat grown in substrates amended with 10% bentonite or not during the development of durum wheat in monoculture and in association with the chickpeas were analyzed. The results showed that the total nitrogen content of durum wheat was significantly higher at three leaves and tailoring stages, when durum wheat was associated with chickpea in the same soil. However, the results showed no difference during the lifting and two leaves stages. There was also a positive effect of treatment at 10% of bentonite on the plant total nitrogen content regardless of the stage and the culture system. Key words: Sandy soil, bentonite, arid zones, durum wheat, chickpea, physicochemical characterization of soil.

1. Introduction The Mostaganem plateau covers 212,000 hectares of farmland of which 60% are sandy soils, high porosity, blocky structure, brown (7.5YR 4/6), effervescence to HCl [1]. They are characterized by very low fertility and water holding capacity [2] and a very limited microbial activity which leads to loss of organic matter [3]. This low fertility is one of the constraints in this region limiting agricultural production mainly cereals which requires improvement by industrial fertilizers to increase crop yields. Indeed, the technical means to improve the nitrogen content of these soils are limited due to the low presence of clay, and improper physico-chemical conditions in the mineral nutrition of wheat in particular nitrogen [4]. The crop response to nutrients

Corresponding author: H.Y. Reguieg, Ph.D., research fields: materials for wastewater treatments, photocatalysis, environment. E-mail: [email protected].

is often limited by lack of nitrogen in the soil [1]. Irrational cultural practices affect manifestly plant development [5]. For sustainable agriculture, it will be wiser to plan for a rational management of cultivated land by using natural resources. In this perspective, introducing clay-rich bentonite can improve the physical and chemical characteristics of these soils. This action will increase cation exchange capacity [6], and improve soil structure leading to a good water and nutrients retention and a better soil ventilation [7, 8]. The approach for the development of a culture system combining a legume and cereal in bentonite amended soil can be a model to improve fertility and increase crop production. The introduction of nitrogen fixing legumes in combination with a cereal, by means of the symbiotic association with nitrogen fixing bacteria, can replace industrial nitrogen fertilizer and hence reduce land pollution. The aim of this study was to evaluate the effect of bentonite amendment on the total nitrogen content of durum wheat grown with

Effect of Bentonite on the Sandy Soils of Arid Regions: Study of Behavior of an Association of Wheat and Chickpea

chickpea and in monoculture.

2. Materials and Methods The experiments took place in three stages: (1) During the first stage analysis of physical and chemical characteristics of studied substrates are performed in the laboratory; (2) The second stage focused on the agronomical study on durum wheat in monoculture and in combination with a legume (chickpea) on 10% bentonite substrate; (3) The third stage was carried out in the field under natural conditions to study the behavior of durum wheat in combination with a legume in soils treated with 10% bentonite. 2.1 Biological Material Two species were tested: durum wheat (Triticum durum) local variety (Waha) and a legume, chickpea (Cicer arientinum. L) (variety ILC 3279).

conduct of cultures in a first phase, the seed germination of durum wheat was carried out by placing 20 seeds between layers of sterile filter paper soaked in distilled water in glass Petri dishes of 20 cm diameter. These were placed in a germination chamber set at 25 °C for 3 days. The same method was used for chickpea seeds where the germination lasted for five days. After germination, 4 to 5 seedlings for durum were carefully transplanted to pots at 1 cm depth. For the association of durum wheat and chickpea, 6 Table 1 Mineralogical and chemical composition of raw bentonite (brought from Mzila Mostaganem) [12]. Mineral composition Chemical composition Minerals

Content%

Component

Content%

Montmorillonite

45-50

SiO2

61.20

Quartz

15-20

Al2O3

13.50

Feldspath

3-5

CaO

4.52

Carbonate

8-10

MgO

2.78

Biotite

8-10

Na2O

1.57

Volcanic glass

8-10

K2O

1.73

Rock fragment

2-4

FeO3

3.55

·< 1

Pyroxene

2.2 Laboratory Experimentation The substrate was prepared from bentonite, previously ground using an electric grinder and sifted through a 2 mm sieve to obtain a fine powder to be easy to mix. The analysis of Table 1 shows that the bentonite of Mostaganem contains mainly montmorillonite 45-50%, SiO2 content is very important (61.20%), followed by Al2O3 (13.50%). It contains 60% clay particles [9]. A dose of 10% bentonite is used, because phyto-technique studies conducted on durum wheat, maize (Zea mays) and some legumes have confirmed that the yields achieved increased gradually as the dose of bentonite incorporated into the soil increased, reaching an optimum at 10% treatment, then decreased to the final dose of 15% [1, 10, 11]. The 10% dose is calculated in relation to the dry weight of soil, i.e. 500 g of bentonite per pot, the control pot contains only the sandy soil (Table 2). The substrate is mixed vigorously to obtain a homogeneous mixture. For the

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Table 2 soils.

Particle size and chemical analysis of studied Soil type Sandy soil

10% bentonite soil

Soil characteristics A

6.27

8.36

Particle size L analysis (%) S

13.37

11.73

CT pH

80.36

79.91

S

SL

Water

8.13

8.23

KCl

7.99

7.99

30.47

33.81

CaCO3 total (%) P2O5 (‰)

2.08

2.47

C%

0.4

0.6

N%

0.06

C/N

6.66

13.33

CEC meq/100 g of soil

10.89

23.09

4.1

10.2

1.6

6.6

0.43

3.59

4.76

2.7

MO

2+

Ca Exchangeable Mg2+ bases meq/100 g Na+ of soil K+

0.045

A: clay, L: silt, S: sand, CT: textural class, MO: organic matter, CEC: cation exchange capacity.

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seedlings were transplanted per pot, three of wheat and three of chickpea. The used pots were made of plastic with a diameter and height of 24.6 cm and 21 cm respectively. The bottom of each pot was lined with a layer of gravel to ensure good drainage. Each pot was filled with 5 kg substrate. The experiment was conducted in controlled conditions in a greenhouse at a temperature of 20 °C during daytime and 15 °C during night and a relative humidity of 70%. The method used was that of RCBD with three replicates. The plants were watered with the diluted (1:1000) solution of Hoagland [13] every three days on the basis of the retention capacity of the substrate. The irrigation doses were determined by difference between the amount of water used before watering and that retrieved after 24 hours of soil drainage. Chickpea was inoculated with Rhizobium ciceri isolated from nodules of the same variety of chickpea (ILC 3279) harvested after eight weeks of cultivation in sandy soils. Under sterile conditions the inoculum was poured at the base of shoots of young seedlings. The remaining space of the hole is plugged with sterile cotton. 2.3 Field Experimentation The experimental device was set up at the Agronomic Station of the University of Mostaganem in the year 2001/2002 during winter and spring period with an average rainfall of 355 mm, followed by a period of exceptional drought. Before sowing, the soil was prepared according to cultural practices adopted in the region. Each lot covers an area of 1,250 m2 or 25 m × 50 m with distance of 6 meters between lots to avoid root competition effect. The soil was mixed with bentonite to 10%. Sowing was carried out mechanically in early February 2001 using a seed drill to a depth of 3 cm to ensure proper distribution of seed and regular growth of the plant without fertilizer. The seeding rate was 150 kg/ha for lots of durum wheat, whereas for the lots of durum wheat/chickpea association, only 50 kg/ha of chickpea and 75 kg of

durum wheat were used. Measurements of agronomic parameters on plants aerial parts included stem height (cm), shoot number/m2, spike number/m2, grain number/spike, grain number/m2, the weight of 1,000 grains and grain yield in quintals/ha to the harvester. At the end of the plant cycle, we carried out the harvest, taking care to adjust the harvester according to the following steps: (1) Setting cons drummer: some space between the drummer and the drummer cons was given to avoid seed crushing of chick peas; (2) Adjustment of grid: the grid must be positioned in a higher position to allow better recovery of wheat; (3) Adjustment of the grader cylinder: in the case of mixed crop, a cylindrical grid was used for wheat, which helps channel the refusal of chickpeas and a clear exit which is at the end of the cylindrical grid was used for the recovery of chickpea. 2.4 Methods of Analysis Measurements on durum wheat samples were made at the beginning of each stage of growth (emergence, 2 leaves, 3 leaves, and beginning of tillering). They were washed with distilled water, dried in an oven at a temperature of 60 °C. After fine grinding, 0.2 g of dry matter was taken for total nitrogen determination, then mineralization assay was performed according to Kjeldahl method (for durum wheat this analysis was carried out on the whole plant at each growth stage). Soil Analysis: (1) Physical Analysis: Particle size analysis was made according to the international method of sedimentation using the robinson pipette. (2) Chemical Analysis: The pH was measured by a pH meter, on a diluted suspension of soil (2:5). Two types of pH are made: the water pH and KCl pH. The electrical conductivity is measured using a conductivity meter. The limestone aggregate is determined by Bernard method and calcimeter active limestone by Drouineau Boulder method. The organic


carbon is measured by the Anne method. Organic carbon is oxidized by potassium dichromate in sulfuric medium. Dichromate must be in excess. The reduced amount is generally proportional to the organic carbon content. The excess potassium dichromate is titrated with Mohr’s salt solution in the presence of diphenylamine whose color changes from dark blue to blue green. After determining the organic carbon content, organic matter content is estimated using the following equation: % organic matter = % of organic carbon × 1.72. For the determination of total nitrogen we used the method of Kjeldahl. The Aubert method was used for the determination of phosphorus (P2O5). 2Determination of (Cl , HCO3 , CO3 ) to the volume assay was used. The study of exchange capacity and exchangeable cations of soil the acetate method of ammonium solution and normal neutral was used. The

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and magnesium in abundance is due to the presence of a limestone slab [14, 15]. The origin of sodium bentonite explains the high rate of Na+ in the soil at 10% bentonite. Whereas, decreased potassium in soil enriched with bentonite is due to the original sandy soil naturally rich in K+ and not to the applied bentonite. Our results indicate that the content of this element is higher in the non treated soil. Regarding the increase in total calcium content, the presence of limestone slab located at 70 cm from the ground surface is at the origin [1, 16]. 3.2 Agricultural Study in Laboratory 3.2.1 Nitrogen Content of Durum Wheat 3.2.1.1 Nitrogen Content of Durum Wheat in Emergence and Two-Leaf Stages Fig. 1 shows that in the control substrate, the total nitrogen content of durum wheat is the same in

results were analyzed statistically using ANOVA software. The values are the statistical average of

association durum wheat and chickpea and durum

three replicates with a confidence interval calculated at 0.05 as shown in Table 2.

bentonite to sandy substrate increases the total plant

3. Results

durum wheat in both cropping systems (0.08%). The

wheat monoculture (0.05%). The addition of 10% nitrogen, the levels become higher but identical in results show the positive effect of bentonite treatment

3.1 Physical and Chemical Characterization of the Culture Substrate

on the total nitrogen content of the plant regardless of

The application of 10% bentonite in the soil has caused a change in soil texture. The substrate passes from the sandy-textured to sandy loam. The addition of bentonite in the growing medium does not represent a major influence on the total lime. Organic matter increases in the substrate when the bentonite is added. The C/N undergoes a significant increase. The substrates used are low in nitrogen. The exchangeable bases, including calcium and magnesium, are dominant. The exchangeable sodium increases with the dose of bentonite applied, while the exchangeable potassium decreased. The results described above involve a number of comments. Indeed, the presence of soluble calcium

During the emergence and two-leaf stages, the total

the cropping system. nitrogen content of durum wheat increased in plants grown on bentonite-treated

substrate regardless of

the type of crop. Its content remains low in plants of

Fig. 1 Total nitrogen content of wheat in emergence stage.

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Control (bentonite 0 %)

Plant nitrogen (%)

Fig. 2 Total nitrogen content of wheat in two-leaf stage.


Fig. 3 Total nitrogen content of wheat in three-leaf stage.

Plant nitrogen (%)

3.2.1.2 Nitrogen Content of Durum Wheat in Three-Leaf Stage At this stage (Fig. 3), increased total nitrogen content of durum wheat is expressed in sandy substrates or bentonite-amended substrates in both monoculture durum wheat, or in association with chickpea. In untreated substrates, the concentration of total nitrogen increased from 0.08% in durum wheat monoculture to 0.1% in the association cropping system. When sandy substrates are amended with 10% bentonite, the total nitrogen content of durum become very high and reaches 0.15% in durum wheat monoculture against 0.17% in combination with chickpea. Analysis of variance indicated that the effect of bentonite on the nitrogen content of durum wheat in sandy substrate is highly significant compared with the sandy substrate without bentonite including the durum monoculture. Statistical analysis shows that the nitrogen content of durum in the bentonite-amended substrate remains significantly high compared to the substrate without bentonite. Furthermore, the cropping system chickpea-durum combination expresses a significant influence on the nitrogen content of wheat in sandy substrate and that of bentonite-amended. 3.2.1.3 Nitrogen Content of Durum Wheat at Early Tillering The total nitrogen content of durum wheat at this stage (Fig. 4) varies in a remarkable increase in the media where it was cultivated in association with chickpea. In sandy substrates nitrogen content increased from 0.09% in durum wheat monoculture, reaching a value higher than 0.12% in combination with chickpea. The addition of bentonite to sandy substrate creates an enrichment of total nitrogen in durum much more important in the cropping system compared to the sandy substrate (0.23 against 0.12%). The treatment of sandy substrate with bentonite significantly alters the levels of nitrogen in the plant regardless of the culture system. However, the effect

Plant nitrogen (%)

control substrate (0.12% against 0.07%) (Fig. 2).


Fig. 4 stage.

Total nitrogen content of wheat in early tillering

of cultivation system on plant nitrogen is expressed in highly significant way in the sandy substrate and significantly in the bentonite-amended substrate in combination culture system.


which promote a rapid and significant growth. The important root density in chickpea permits the soil to have good air and water circulation in the rhizosphere. The presence of bentonite has increased the soil nutrient reserves. A strong relationship was noted for all treatments between the dose of bentonite, cropping system and plant biomass. 3.3 Results of Lots: Measured Agronomic Parameters The height of the stem (Fig. 7) varies within a margin of 41.4 cm recorded from monoculture wheat plants to an average height of 52.5 cm in the association culture. It increases in this later much more than in monoculture to achieve a maximum value of 53.7 cm. The results illustrated in Fig. 8 show that 6.1 spikes per plant were obtained during the

Stem heigh (cm)

Stem heigh (cm)

Stem heigh (cm)

3.2.2 Measurements of Leaf Area and Stem Height of Durum Figs. 5 and 6 show that leaf area and height growth of the stem are much higher in the case of the association durum wheat and chickpea in all stages and treatments. The values of these two parameters appear higher for plants grown on substrate with 10% bentonite. Analysis of variance indicated that the effect of the amendment with bentonite sand substrate on biometric measurements of durum wheat is significant compared with the sandy on bentonite amended-substrate not including durum monoculture. We explain this difference in growth between the vegetation types by the fact that the presence of chickpea associated with durum wheat makes good use of nutrients in the soil solution by wheat roots



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Leaf area (cm2)

Leaf area (cm2)

Leaf area (cm2)

(a) (b) (c) Fig. 5 Changes in stem height in plants of wheat monoculture and wheat in association with chickpea in stage of: (a) emergence; (b) 3 leaves; (c) early tillering depending on the dose of bentonite. The black bars represent the standard deviations.




(a) (b) (c) Fig. 6 Changes in leaf area in plants of wheat monoculture and wheat in association with chickpea in stage of: (a) emergence; (b) 3 leaves; (c) early tillering depending on the dose of bentonite. The black bars represent the standard deviations.

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Fig. 7 Average height of the stem of wheat in monoculture and in association with chickpea at maturation stage in lots with 10% bentonite.

Vegetation type

Fig. 8 Variation in number of spikes of wheat grown in monoculture and in association with chickpea in maturation stage in 10% bentonite lots.

maturation stage. Whereas, in monoculture the average values vary between 2.6 to 2.9 spikes per plant. Grain yields obtained in substrates with 10% bentonite grown in association (wheat/chickpea) in the field are significantly higher for all plants regardless of the lot (Table 2) compared with those in monoculture wheat (Fig. 9). The yield values ranged from 7.84 in Lot A3 to 8.16 and 8.56 quintals/ha respectively in lots A2 and A1, these yields fall between 4.96 quintals/ha in lot B2 and 5.2 and 5.36 quintals/ha in lots B3 and B1 durum wheat monoculture. This remarkable increase in yields in the substrates with bentonite grown in association is due to the effect of the microclimate created by chickpea. These yields are generally low (9 quintal·ha-1), this is mainly due to a severe drought during the experiment and the

absence of fertilizers. The statistical analysis shows that the effect of the combination wheat/chickpea on yield is highly significant. Grain yield in substrate grown in association is higher compared to the soil grown in monoculture. The rate of increase in grain yield was about 18.32%.

4. Discussion The essential points that could be retained from the results of this work are: During the emergence stage, the high level of total nitrogen of wheat grown in substrates with 10% of bentonite is due to the presence of up to 0.81% organic matter in bentonite [17]. However, similarity of total nitrogen in wheat in monoculture and in association (0.05-0.08%) in control substrate and substrate with 10% bentonite is due to development of plant growth at the expense of reserves in seed.


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Fig. 9 Variation of total yield of wheat in monoculture and in association with chickpea in maturation stage in 10% bentonite lots.

In early-stage tillering, gradual evolution of total nitrogen of durum wheat is quite important due to the needs of durum wheat to nitrogen. Our results support the work of Meynard et al. [27], in which they showed that nitrogen nutrition starts from the grass tillering, with dominant effects from the spike stage to flowering. This increased level of nitrogen is due to its strong accumulation at early tillering [1]. The recorded variations in the concentrations of total nitrogen analysis of durum wheat in bentonite-free and bentonite amended substrates in different cropping systems do not exclude the influence of other factors. It has been shown that the addition of bentonite to sandy soils led to retaining their structural stability [2, 18] and improving their chemical properties [19]. Our results indicate that wheat grown in sandy substrates and monoculture is poor in nitrogen, due to the low clay content and the absence of organic matter [16] leading to nutrients leaching [20]. According to Labdi [21], the nitrogen-rich organic matter in chickpea contributes to improving soil structure and subjected to erosion, such as sandy soils. The crop type proposed in this work, is the association of durum wheat and chickpea in sandy substrates amended with bentonite, because of the strong increase in total nitrogen content of durum. Under these conditions, the combined action

of chickpea and bentonite reflects a beneficial effect on the behavior of durum wheat due to better availability of soil nitrogen in the substrate [22]. These results are confirmed by measurements of stem height (Fig. 5) and leaf area (Fig. 6) that are significantly higher in the case of the association durum wheat + chickpea for all stages and conditions treatment. The values of these two parameters appear higher for plants grown on bentonite amended substrate. We can explain this difference in growth between the vegetation types by the fact that the presence of chickpea associated with durum wheat makes good use of nutrients in the soil solution by roots of durum wheat in promoting growth rapid and significant. The density of the legume root substantial ground has to have a cooling water circulation and fairly consistent in the rhizosphere, the contribution of the bentonite has increased dramatically in the soil nutrient reserves. A strong relationship was noted for all treatments between the dose of bentonite, total nitrogen content of durum wheat cropping system and plant biomass. For the cons decrease in biomass is significant and confirmed the substrates not subject to the bentonite and durum wheat grown in monoculture until the last stage of the growth of durum wheat. These variations of nitrogen in the plant in different growing media involve the role attributed to the

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legume symbiotic fixation of atmospheric nitrogen by bacteria [23-25]. For all treatments a strong correlation was also recorded between the bentonite treatment and the number of ears in the field. This increase in the number of spikes in the association is explained by the strong absorption of fixed nitrogen to promote tillering for growth and the rise of tiller spikes. Wheat accounts for about 40% of nitrogen during this period [26-28]. Increased yields expressed in plants grown on bentonit substrate and manifests for durum wheat in combination with the chickpeas. This yield increase is due partly to the nitrogen supplied by the legume. For, after O’brain and Mayor [29] using bacteria to improve soil structure around the roots is a novel method for increasing crop yield. Moreover, Lindwall [30] reported that chickpea stubble creates a microclimate for wheat by the author, the height of stubble would affect the ability of water use. The difference in the evolution of agronomic parameters measured between the association and monoculture wheat is due to the effect of chickpea on durum resulting in the fixing of atmospheric nitrogen by exerting influence on growth of the plant and allows a quick start causing significant tillering. According to Alami [31], rhizobium produces a polysaccharide gelling around plant roots, which is able to alter the soil structure by improving mineral nutrition, particularly nitrogen which is a key determinant of growth and stem elongation by stimulating the vegetation and promoting tillering of wheat. However yields are low without the addition of bentonite, they are even lower when durum wheat is grown in monoculture. Statistically the difference in performance between the two vegetation types is

nitrogen content of durum wheat is identical to 2-leaf stage up and the culture system in the control substrates and 10% bentonite. Since the 3 leaf stage, the total nitrogen increases in durum sandy substrates or without the addition of bentonite from the system disk to monoculture wheat cropping system of wheat + chickpea drive. The nitrogen enrichment of durum on bentonite amended substrate appears remarkably at early tillering under particular culture associated with chickpea durum. Without amendment and without bentonite combination of legume cultivation of durum wheat, there is a risk of a rapid decline in the level of nitrogen. The decreased concentration of this element is responsible for reductions in yields. The accompaniment by the amendment of bentonite of a legume crop in association with durum wheat yields would increase. The results of our research could serve as tools in improving farming methods, soil management, approaches to the implementation of sustainable development. In Algeria, wheat is the most widely grown cereal in arid and semi arid with low rainfall, where low yields are obtained mainly due to lack of water, improper use of fertilizers and low soil fertility especially sandy soils. Such soils require optimization in improving interactions between plants and microorganisms in the rhizosphere ensuring a sustainable balance of the biotope. Upon completion of this work, bentonite could be a very promising material for the improvement of the physical, chemical and biological properties of sandy soils in arid regions including those of Mostaganem plateau which would contribute positively to improved production yields agriculture in this region.

highly significant.

References

5. Conclusion

[1]

The levels of total nitrogen measured in durum vary with the nature of the substrate and the growing conditions of the durum wheat. While the total

[2]

Y.H.A. Reguieg, Contribution to understanding the dynamics of nutrients NPK in major cereal soil of Tiaret region, Ph.D. Thesis, Algiers, 1992. S. Goa, W.L. Pan, R.T. Koeining,. Integrated root system age in relation to plant nutrient uptake activity, Agron. J. 90 (1998) 505-510.

Effect of Bentonite on the Sandy Soils of Arid Regions: Study of Behavior of an Association of Wheat and Chickpea [3]

B. Morsli, M. Mazour, N. Medjedel, A. Hamoudi, Influence of using soils on the risk of runoff and erosion on the semi-arid slopes of Northwestern Algeria, Sécheresse 15 (2004) 96-104. [4] H.N. Le Houerou, Climate change and desertification, Sécheresse 2 (1993) 95-111. [5] J.M. Ambouta, C. Valentin, Fallow and erosion crusts in the Sahel, Sécheresse 7 (1996) 269-275. [6] J. Dejou, The specific surface of clay, its measurement, relationship with the CEC and its agronomic importance, in: Proceeding Symposium AFES, 1987, pp. 72-83. [7] S. Raimund, S. Dietmar, Properties of soils under different types of management developed in a sandy substrate covering boulder clay at Mecklenburg (north eastern Germany), in: Sciences of Soils, 1996. [8] M. Benkhalifa, Influence of bentonite on the physical, hydric and mechanical properties of a sandy soil of the plateau of Mostaganem, Ph.D. Thesis, Algiers, 1997. [9] H. Derdour, Influence of exchangeable sodium content on the mechanical properties (compaction) of an artificial material, sand-bentonite mixture, Sciences du sol, Plaisir Edition, France, 1985, pp. 107-114. [10] Z.A. Engelthaler, A. Lostak, The Use of Bentonite for Soil Improvement, ONUDI Edition, Pilsen, Czech Republic, 1983, p. 184. [11] A.F. El Sherif, Research project on the improvement of sandy soils, methods and economics aspects, Final Report ARST, Caire, Egypt, 1987, p. 182. [12] National Company Products and Ferrous Materials Useful, Algiers, 2002. [13] D.R. Hoagland, D.I. Arnon, The water culture method for growing plants without soil, Calif. Agric. Exp. Stn. Bull. 347 (1938) 36-39. [14] A. Ruellan, Contribution to the understanding of soils of Mediterranean regions, the limestone soil profile differential plains of Lower East Moulouya Morocco, The University of Strasbourg Mémoires, 1971, p. 302. [15] A. Halitim, Soils of Arid Regions of Algeria, Office of University Publications, Algiers, 1988, pp. 19-28. [16] B. Rouiba, Evolution of physicochemical parameters of water and soil subjected to different doses of bentonite, Mémoire Ing. INFSA. Mostaganem, 1994, pp. 27-33. [17] A. Bendella, Study of the binding of barium by deck bentonite, Bachelor of Science Desertation, Mostaganem, Algeria, 1994. [18] Y.H. Reguieg, M. Belkhodja, The effects of bentonite on the physico chemical characteristics of sandy soils in

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Algeria, Egypt, J. of Appl. Sci. 21 (2006) 376-385. [19] D. Boutalbi, Literature research on improving sandy soils with bentonite, Science Desertation, Mostaganem, Algéria, 1995. [20] B. Cherbury, Saline soils and their rehabilitation, bibliography, ENSA Rennes, 1991. [21] M. Labdi, Development perspective of legumes in cereal systems in semi-arid, Céréaliculture 25 (1991) 12-13. [22] M. Bouhali, Effect of bentonite on durum wheat submitted in conjunction with a legume (chickpea): Study of nitrogen balance in the soil, the rhizosphere, Science, Desertation, Mostaganem, Algéria, 2002, pp. 47-60. [23] M. Sanchez-Diaz, J. Aguirreolea, M.C. Goicochea, M.C. Antolin, Limitations of symbiotic nitrogen fixation and other physiological aspects of legumes of Mediterranean areas, National Institute of Agronomic Research, France,1995, pp. 11-29. [24] M.E. Gavito, P.S. Curtis, T.N. Mikkelsen, I. Jakobsen, Atmospheric CO2 and mycorrhiza effects on biomass allocation and nutrient uptake of nodulated pea (Pisum sativum L.) plants, J. Exp. Bot. 51 (2000) 1931-1938. [25] L. Ben Khaled, A. Gõmez, M. Ouarraqi, A. Oihabi, Physiological and biochemical responses of clover (Trifolium alexandrinum L.) double-rhizobium association mycorrhizae under saline stress, Agronomy 23 (2003) 571-580. [26] C. Ciprianos, Tests of nitrogen fertilization on three varieties of durum, Inst. Chim. Univ., Mostaganem, 1984, pp. 38-43. [27] J.M. Meynard, E. Justes, J.M. Machet, S. Recous, Nitrogen Fertilization of Annual Field Crops, National Institute of Agronomic Research, Paris, 1998, pp. 271-288. [28] S. Recous, J.M. Machet, Short term immobilisation and crop uptake of fertilizer N applied to winter wheat: Effect of date of application in spring, Plant Soil 206 (1999) 137-149. [29] M.R. O’Brain, R.J. Maire, Molecular aspect of the energetics of nitrogen fixation in legume symbiosis, Biophysics Acta. 974 (1989) 229-246. [30] W. Lindwall, A New Class of Wheat, CARSAL, Canada, 2000, p. 10. [31] Y. Alami, Role of exopolysaccharide-producing bacteria (Rhizobium sp.) in the rhizospheric soil aggregation of sunflower: Effects of inoculation on soil structure and mineral nutrition of the plant, Ph.D. Thesis, France, 1997.


D DAVID

PUBLISHING

Effect of Foliar Copper Fertilizer on Pineapple cv. N36 Planted on BRIS Soil at East Coast of Peninsular Malaysia A.M. Arshad1, A.A. Marzuki2 and A. Aziz2 1. Department of Agro-technology, Faculty of Agro-technology and Food Sciences, Universiti Malaysia Terengganu, Kuala Terengganu, Terengganu 21030, Malaysia 2. Department of Biological Sciences, Faculty of Science and Technology, Universiti Malaysia Terengganu, Kuala Terengganu, Terengganu 21030, Malaysia Received: June 8, 2011 / Accepted: June 29, 2011 / Published: December 20, 2011. Abstract: The physical and chemical properties of BRIS soil are unsuitable for agricultural purposes. A proper fertilizer and crop management practices are required. An attempt was made to convert this land into a sustainable production land for pineapple. Therefore, the objective of the study was to determine the effect of foliar copper fertilizer on the growth and fruit quality of pineapple, cv. N36, for fresh consumption planted in Entisol type BRIS soil at the east coast of Peninsular Malaysia. The complete randomized design (CRD) method with three replications was used at 0 to 6.6 kg·ha-1 of copper sulfate. Results demonstrated that the unpleasant effect of BRIS soil on brix value was restored with copper fertilizer. The most suitable quantity of foliar copper fertilizer for pineapple cv. N36 planted in Entisol type BRIS are between 1.6 to 3.3 kg·ha-1 of copper sulfate. Key words: Brix-value, copper sulfate, entisol, ethephon, muriate of potash, urea.

1. Introduction BRIS (Beach Ridges Interspersed with Swales) soil is a problematic soil in Malaysia. This soil is distributed generously along the east coast of Peninsular Malaysia, from Kelantan, Terengganu, Pahang and right down along the east coast to the west coast of Johor. It was classified into Entisol order which consists of Rompin, Rusila, Baging, Jambu and Merchang series and Spodosol order, which contains only the Rudua series [1]. The physical characteristics of BRIS soil are too sandy, weakly structured, nutrient deficient and low water retention capacity, limited ability to support plant growth and having a relatively high soil temperature. These characterizations have caused BRIS soil unsuitable for agricultural purposes. Corresponding author: A. Aziz, Ph.D., associate professor, main research field: plant biochemistry and physiology. E-mail: [email protected].

Attempt had been made to utilize this soil for crops plantation. Proper farm practices with good irrigation and fertilization management is one of success key factor. Pineapple is one of plant of choice due to its lower water requirement than the vast majority of cultivated plants [2]. It has a series of morphological and physical characteristics typical of xerophile plants. It has the capacity to store water in the hypoderm of the leaves, to collect water efficiently, including dew, in its trough-shaped leaves, and to considerably reduce water loss (reduced transpiration) by several mechanisms. Furthermore, pineapple adapts well to acidic soils with optimal pH 4.5 to 5.5 [3] which commonly occurred at BRIS soil area. In addition, the pineapple has a large demand for plant nutrients and the amounts required often exceed those which the majority of cultivated soils can supply. For this reason,

Effect of Foliar Copper Fertilizer on Pineapple cv. N36 Planted on BRIS Soil at East Coast of Peninsular Malaysia

fertilization is almost mandatory where the fruit is destined for sale. Copper (Cu) is one of essential micronutrient, which is a component of various protein particularly those involved in photosynthetic and respiratory [4]. Elevated Cu is strongly phytotoxic and may alter membrane permeability, chromatin structure, protein synthesis, enzyme activities, photosynthetic and respiratory processes, and may activate senescence [5, 6]. Its deficiencies can cause light green narrow leaves with wavy borders, a pronounced U-shape in cross-section and a small number of tricomes, short roots with reduced hairs and stunted plant [2]. Reducing the root length would cause a severe effect on plants grown especially at low water retention capacity soil. Toriman and co-workers [1] show that the Rusila series of BRIS soil contain a minimal quantity of copper. Thus, the objective of present study was to determine the effect of copper sulfate fertilizer applied on foliar of pineapple cv. N36 planted in BRIS soil.

2. Materials and Methods Planting materials of pineapple “N36”, a hybrid of “Gandul” (“Singapore Spanish”) and Sarawak (“Smooth Cayenne”) were obtained from Department of Agriculture Malaysia, Johor. Plantlet was grown in poly-beg (60 × 50 cm) containing mixtures of 30 kg Rhusila series soil obtained from Rhu Tapai, Setiu, Terengganu, Malaysia. The plants were arranged according to complete randomized design (CRD) with three replications. Fertilizer was applied twice followed to suggestion by Agriculture Department, Malaysia: urea (45% N) at 434 kg·ha-1, triple super Table 1

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phosphate (TSP; 48% P2O5) at 50 kg·ha-1, Muriate of Potash (60% K2O) at 591 kg·ha-1, sodium at 1666 kg·ha-1 and magnesium (30% MgO) at 26.6 kg·ha-1. Copper sulfate solution was sprayed on foliar at 0, 0.8, 1.6, 3.2 or 6.4 kg·ha-1. All plants were placed under shade in Green House at Universiti Malaysia Terengganu and watering at two day interval. Flowering was induced with 50 mL per plant of 2 ml·L-1 2-chloroethylphosphonic acid (ethephon) solution applied to center of each leaf rosette [7]. The plant growth (Table 1) and fruit development (Table 2) and other parameters (Table 3) were measured accordingly to the standard method. Copper content in tissues and soil were analyzed according to the method by Chapman and Pratt [8], and Double Acid method [9], respectively, using Atomic Absorption Spectrophotometer (ASS). Data was analyzed with ANOVA using SAS software, and mean was compared using Duncan’s Multiple Range Test (DMRT) (p = 0.05).

3. Results and Discussion Plants normally take up nutrients from soils through their roots, in some cases nutrients can be absorbed through leaves which normally supplied to plants as fertilizers by foliar sprays. Accumulation of certain micronutrients in soils, such as copper (Cu), an essential micronutrient, can be toxic in excess for most plants. In present study, the copper sulfate fertilizer applied on foliar of pineapple cv. N36 had no significant effect on the growth parameters (Table 1). Plant height was fluctuated between 73 to 84 cm, while 6.6 kg·ha-1 produced the highest the leaf number and plant height. Similar responses were observed on

Effect of copper on growth of pineapple plantlets after six months grown on BRIS soil.

Copper Plant height Leaf number D-leaf length D-leaf area D-leaf dry weight Treatment (kg·ha-1) (cm) plant-1 (cm) (cm3) (g) T1 0 (control) 75.66ab 30a 67.00a 152.67a 4.85a T2 0.8 73.16a 22a 67.16a 150.33a 4.06a T3 1.6 77.33ab 21a 63.80a 162.00a 4.10a ab a a a T4 3.3 74.00 22 64.50 152.00 3.90a b b a a T5 6.6 84.13 42 60.66 149.33 4.12a Values in the same column with different superscripts are significantly different P < 0.05 by Duncan’s Multiple Range Test.

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the length, dry weight and surface area of D-leaf, where no differences were observed between the treatments. This indicates that the amount of copper fertilizers used in this study did not reach the toxicity levels for cv N36. Elevated copper fertilizer was reported to reduce the length of D-leaf [10] and chlorotic symptoms. Copper has capacity to initiate oxidative damage and interfere with important cellular functions such as photosynthesis, pigment synthesis, plasma membrane permeability and other metabolic disturbances that are responsible for a strong inhibition of plant development [11]. The cv. N36 fruit weight was affected by copper fertilizer (Table 2). The 1.6 kg·ha-1 demonstrated the highest fruit weight compared to others. The fresh weight and length of fruit was decreased at higher doses especially when 6.6 kg·ha-1 of copper sulfate was used. Similar phenomenon was observed on brix-values (Table 2). Brix-value for pineapple cultivar N36 was reported at 15% to 17% [12]. The higher brix value, the healthier and more nutrient/mineral rich the plant is. The result revealed that Entisol type BRIS soil had caused unpleasant effect on brix value of cv. N36. It was 11.5% reduction of brix value in cv. N36, which approximately 0.7-fold lower than the control. Interestingly, foliar copper fertilizer was managed to maintain the brix value. In treatment T3 (1.6 kg·ha-1) the brix-value was remained as 15%, which is the natural velocity in this cultivar. It was 1.3-fold higher compared to unamend. The ability to sustain the brix value is essential for production of healthy and nutrient rich fruit as the brix values represent the total Table 2

soluble solid content in the fruit juice. Nonetheless, the brix value had decreased when 6.6 kg·ha-1 of copper fertilizer was applied. It was 0.8 and 0.6-fold lower than control and natural velocity for cv. N36, respectively. This might be due to effect of elevated copper in the plant tissue. Under excess Cu the protein biosynthesis, enzyme activities, photosynthetic and respiratory processes are altered [5, 6]. In addition, the brix value was reported to be altered by fertilizer [13] and foliar fertilizer [14, 15] used. In the other hand, copper fertilizer had triggered the excessive growth of crown. The crown fresh weight was increased accordingly with quantity of fertilizer applied (Table 2). Over growth of crown might be due to Cu accumulation on the top of fruit, which subsequently increased the chlorophyll content and photosynthetic activity [16]. High photosynthetic activities indirectly would enhance the biosynthesis of carbohydrate and proteins including the detoxification enzymes [6]. Although bioaccumulation of copper was reported to expanding leaves of bean seedlings [5] and cucumber [10], crown length was not significantly affected. Foliar copper fertilizer increased the soil pH 0.4 to 0.8, depending on the amount of fertilizer used. Meanwhile, the quantity of copper in the D-leaf was fluctuated between 12.6 to 26.7 ppm. The highest copper content in D-leaf was observed in T4, but no significant different compared to T3 and T5 (P > 0.05). Foliar copper fertilizer higher than 3.3 kg·ha-1 had no significant effect on the copper content in D-leaf (Table 3). Copper content in the soil remains low, with no difference between the treatments. These findings suggest that the use of copper sulfate

Effect of copper on fruit pineapple grown on BRIS soil.

Copper Fruit weight Fruit length Fruit diameter Brix Crown weight Crown length Treatment (kg·ha-1) (g) (cm) (cm) (%) (g) (cm) T1 0 (control) 420a 9.30a 8.90a 11.5a 212.0a 37.15a T2 0.8 430a 9.20a 9.00a 11.5a 363.3b 34.53a b a a b b T3 1.6 490 9.90 9.20 15.0 383.3 35.30a T4 3.3 430a 9.00a 9.10a 12.1a 433.3c 36.63a c b a c c T5 6.6 350 7.5 8.20 9.6 450.0 39.80a Values in the same column with different superscripts are significantly different P < 0.05 by Duncan’s Multiple Range Test.

Effect of Foliar Copper Fertilizer on Pineapple cv. N36 Planted on BRIS Soil at East Coast of Peninsular Malaysia Table 3

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Copper in leaf and soil, and soil pH after eight months.

Treatment

Copper (kg·ha-1)

Copper in D leaf (ppm)

Soil pH

Copper in soil (ppt)

T1

0 (control)

12.684a

5.53a

56.9a

T2

0.8

14.011ab

5.90ab

47.0a

abc

T3

1.6

17.992

T4

3.3

26.757c

T5

6.6

21.912

b

48.1a

6.33b

42.6a

6.23

bc

5.93

ab

58.00a

Values in the same column with different superscripts are significantly different P < 0.05 by Duncan’s Multiple Range Test.

fertilizer directly to leaves should be considered as good practice to avoid excess copper in the soil that can cause copper toxicity and water pollution. Additionally, the uptake of copper proved to be dependent on the pH of soil, texture and surface area of soil particles, age of plant, growth rate and the varieties of plant species [17].

[3]

[4]

[5]

4. Conclusion It is necessary to apply an appropriate quantity of copper fertilizer on pineapple planted on BRIS soil. For the excellent plant growth and fruit development, the amount of copper fertilizer for pineapple planted on BRIS soil should be in the range 1.6 to 3.3 kg·ha-1. At this range of copper fertilizer the brix-value of pineapple grown on BRIS-soil was improved. Micronutrient fertilizer containing copper sulfate can be sprayed directly on the foliar of pineapple.

Acknowledgments This project was supported by Department of Biological Sciences, University Malaysia Terengganu. The authors thank University for allowing them to use the facilities.

[6]

[7]

[8]

[9] [10]

[11]

References [12] [1]

[2]

H.M.E. Toriman, B.M. Mokhtar, M.B. Gazim, N.A. Abd-Aziz, Analysis of the physical characteristics of bris soil in Coastal Kuala Kemaman, Terengganu, Research Journal of Earth Science 1 (2009) 1-6. E. Malezieux, F. Cote, D.P. Bartholomew, Crop environment, plant growth and physiology, in: D.P. Bartholomew, R.E. Paull, K.G. Rohrbach (Eds.), The Pineapple: Botany, Production and Users, CAB International, New York, 2003.

[13]

[14]

C.E. Alvarez, A.E. Carracedo, E. Iglesias, J.J. Bravo, Pineapple yield and quality on a banana soil of the Canary Islands irrigated with acid and saline water, Tropical Agriculture (Trinidad) 72 (1995) 220-224. M. Baron, J.B. Arellano, L. Gorge, Copper and photosystem II: A controversial relationship, Physiology Plant 94 (1995) 174-180. H. Bouazizi, H. Jouili, A. Geitmann, E. ElFerjani, Copper toxicity in expanding leaves of Phaseolus vulgaris L.: Antioxidant enzyme response and nutrient element up take, Eco-toxicology and Environment Safety 73 (2010) 1304-1308 J.C. Fernandes, F.S. Henriques, Biochemical, physiological, and structural effects of excess copper in plants, Botany Review 57 (1991) 246-273. H.C. Dass, G.S. Randhawa, S.P. Negi, Flowering in pineapple as influenced by ethephon and its combinations with urea and calcium carbonate, Science Horticulture 3 (1975) 231-238. H.D. Chapman, P.F. Pratt, Methods of Analysis for Soils, Plant and Waters, Priced Publication, Berkley, USA, 1961. P.A. Sanchez, Properties and Management of Soils in the Tropics, John Wiley, New York, 1976. F. Vinit-Dunand, D. Epron, B.A. Sosse, P.M. Badot, Effect of copper on growth and on photosynthesis of mature and expanding leaves in cucumber plants, Plant Science 163 (2002) 53-58. M. Bernal, R. Cases, R. Picorel, I. Yruela, Foliar and root Cu supply affect differently Fe- and Zn-uptake and photosynthetic activity in soybean plants, Environmental Experimental Botany 60 (2007) 145-150. H. Abdullah, M.A. Rohaya, I. Abd Aziz, Quality changes in pineapple (Ananas comosus cv. N36) stored at low temperature, MARDI Research Journal 24 (1996) 39-47. A. Almodares, R. Taheri, M. Chung, M. Fathi, The effect of nitrogen and potassium fertilizers on growth parameters and carbohydrate contents of sweet sorghum cultivars, Journal of Environmental Biology 29 (2008) 849-852. L.I. Trejo-Téllez, M.N. Rodríguez-Mendoza, G. Alcántar-González, F.C. Gómez-Merino, Effect of foliar

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fertilization on plant growth and quality of Mexican husk tomato (Physalis ixocarpa Brot.), Acta Horticulturae 729 (2007) 295-299. [15] R.K. Bhattacharyya, A.P. Bhattacharyya, Crop production and harvest index of kew pineapple as affected by foliar application of micronutrients, Acta Horticulturae 296 (1992) 161-164. [16] P.Y. Tong, B.Y. Ling, F.L. Gao, J.H. Wang, Z.Q. Li, S.H.

Di, A study on the effects of copper fertilizer on the growth, development and yield structure of maize, Beijing Agriculture Science 13 (1995) 36-39. [17] R. Salim, M.M. Al-subu, A. Atallah, Effects of root and foliar treatments with lead, cadmium, and copper on the uptake distribution and growth of radish plants, Environmental International 19 (1993) 393-404.


D DAVID

PUBLISHING

Evaluation of Environmental Impacts in the Wood Skidding with Tractors in Greece E. Karagiannis, P. Kararizos and M. Kalaitzi Department of Forest Engineering and Surveying, School of Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece Received: May 17, 2011 / Accepted: July 4, 2011 / Published: December 20, 2011. Abstract: The contemporary demands of the forestry exploitation for quantitative and qualitative increase of timber production are directly related with the mechanization of the wood skidding works. In Greece, the suitable machinery for wood skidding are those with low amortization, operation and installation expenses, are flexible, and may also be used for other farming works (since they are not used very often for wood skidding) and cause the smaller damages to the wood, the forest, the soil and the environment in general. In this paper, it studies the environmental impacts in the remaining stand as much as during the pre-skidding as well as during the main wood skidding with tractor in the forest of Arnaia, Prefecture of Halkidiki, in order to draw out useful conclusions for the improvement of the machinery application methods and the protection of the environment. Key words: Wood skidding, tractor, environmental impacts, remaining stand.

1. Introduction The opening-up of mountainous productive forests was and still is a major problem. The construction of forest roads, skidding tracks as well as the skidding of wood is done in most cases in strongly inclined and rocky soils [1, 2]. As a consequence, in our country, and also in partly Europe, 40%-90% of the inaccessible areas, steep and rocky slopes and the productive forests remain without adequate opening-up [3]. However, the productive forest may accomplish its goals only by management [4]. According to the recent aspects of the forest science, the protective forests should be also exploited in order to maintain their protective role. A necessary prerequisite for their exploitation is that the protective forest should be also opened-up carefully with roads and skidding tracks. In these areas, they are required more sensitive interferences in the nature and exploitation of all Corresponding author: P. Kararizos, assistant professor, main research fields: machinery application in hydronomic and forest engineering works. E-mail: [email protected].

artificial and biological potentials so that the arising damages are kept at tolerable limits [5, 6]. For this purpose, it is necessary for someone to know which are the most appropriate machineries and method for the construction of forest roads, of skidding tracks and for the wood skidding as well. The mechanization of wood skidding works in the Greek forests is adversely affected by the intense topographic relief, the big slopes of soils, the low productivity of forests and the prohibition of clear-cutting fellings. However, the contemporary requirements of the forest exploitation for quantitative and qualitative increase of timber production are directly related with the mechanization of the wood skidding works. In Greece, due to the above factors, the suitable machinery for the wood skidding are those with low amortization, operation and installation expenditures, are flexible, which can be also used for other agricultural works (due to the small time of engagement in the wood skidding) and cause the slightest damages to the timber, the forest, the soil and the environment in general [7].

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Evaluation of Environmental Impacts in the Wood Skidding with Tractors in Greece

As efficient machinery in practice was proved to be the tractors which are a multi-force unit, they are used in almost all works and at the same time they are multi-task machines [8]. Efforts are made for the best possible successful choice, according to the needs of the forest exploitation, aiming at reducing the operational cost of the machinery itself as well as of the tractor-components systems. The older methods for the approach of this problem were rather economical than technical. They used to choose the size of the tractor which had the least cost without taking into consideration of other factors. The recent methods are techno-economic and take also into account the cost arising from the delayed implementation of works. Therefore, the maximum and not the minimum cost is calculated. Recent methods also rely on the time available for the implementation of works and provide less weight on the operation cost (methods with restricted time limits). The latest methods provide very satisfactory results by the use of multiplex algorithms [9]. The skidding of wood in Greece is mainly done by tractors of various types (farming, forest, crawler tractor). The damages occurred to the standing trees adjacent to the wood skidding belt as well as alongside the skidding track are several and a great effort is made to minimize them with continuing studies for the improvement of the machinery operation and for the protection of the environment. This paper recorded, analyzed and calculated the impacts on the environment by the wood skidding works with farming tractors at experimental sites in the public forest of Arnaia, Prefecture of Halkidiki.

follows: (1) Two (2) tractors for the skidding of the logs; (2) One (1) GPS of high precision connected to a portable PC for the plotting of the site and codification of all standing logs; (3) Two (2) clinometers with compass; (4) Two (2) measuring tapes; (5) Three (3) aligning poles; (6) One (1) assistant worker; (7) The total volume of logs resulted from the felling in the under research site was found to be 70.30 m3 (205 logs). 2.2 Method There have been delimitated two (2) experimental sites in the forest stands 116a and 116b as well as two (2) skidding tracks (Fig. 1). After the delimitation and marking of the two (2) skidding tracks of 1165.85 m and 1260.74 m respectively, their digital plotting on the ortho-photomap was done (Fig. 2).

116a

116b

Fig. 1 Map of forest stands 116a and 116b.

2. Materials and Methods 2.1 Materials In summer 2009, all the necessary data was collected at the public forest of Arnaia, Prefecture of Halkidiki where the skidding works of beech logs were in process. The equipment which was used for the research was as

Fig. 2 Digital plotting on the ortho-photomap of the two (2) skidding track in the forest stands 116a and 116b.


After being codified with Roman and Arabic numbers, they were recorded into a portable PC, for sampling reasons, 205 downed logs in the felling site according to the data of their receiption (length and volume in m3) from the forest office. So, we had in code II/5 a downed log of 5 meters long. According to the serial number of received documents, we could find the length and the volume. By the assistance of a portable GPS the positions of 300, standing trees have been marked off and plotted in the boundaries of the skidding track and in the sites of pre-skidding and they were given a code in order to record the damages during the skidding process. Here, we also had the code I/7 which means a standing log with the coordinates of number 7 and serial number 7. After the data processing of the plotting of standing trees in the boundaries of the skidding tracks and in the sites of pre-skidding we came up with the Figs. 3 and 4 of the plotted standing logs. In the felling site, the positions of logs were divided spatially into three slope categories: 0%-30%, 30%-60% and > 60%. For the better determination of the size of damages in cm2 in the standing trees, they have been classified into three classes (Table 1). All the data were uploaded into a PC and therefore we were able to establish the number of downed logs which caused damages during skidding in the standing trees in classes of damages (A, B and C) as well as three categories of classes.

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ground during the hauling of wood in the sites of pre-skidding. The damages caused to the trees of the remaining stand, during the pre-skidding of wood, at a rate of 45% belong to B class (11-100 cm2), at a rate of 33% to A class (0-10 cm2) and at a rate of 22% to C class (> 100 cm2). The damages caused to the trees of the remaining stand, during the major skidding of wood, at a rate of 44% belong to B class, at a rate of 31% to C class and at

Fig. 3 Plotted standing trees in the boundaries of skidding tracks and in the adjacent hauling sites in the forest stand 116a.

3. Results and Discussion From the collection and the process of all data, it concerned the assessment of environmental impacts in the forest stands 116a and 116b of the public forest of Arnaia, Prefecture of Halkidiki. The Tables 2 and 3 as well as Figs. 5 and 6 were formed. Table 2 and Fig. 5 present the damages of the remaining stand per class in connection to the length of logs during the major skidding in the skidding track, while Table 3 and Fig. 6 present the damages of the remaining stand per class in connection to the length of logs and the slope of the

Fig. 4 Plotted standing trees in the boundaries of skidding tracks and in the adjacent hauling sites in the forest stand 116b. Table 1 Classes Α Β C

Size of damage in cm2 in classes A, B and C. Size of damage in cm2 0-10 11-100 > 100

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]

Table 2 Damages (%) of trees of the remaining stand per class in connection to the length of logs during the major skidding of wood on the skidding track. Length of logs (m)

Percentage of trees of remaining stand (%) per classes B C 1 1 2 1 4 3

A 1 1 2

3 4 5

Table 3 Damages (%) of trees of the remaining stand per class in connection to the length of logs and the slope of ground during the hauling of wood in the sites pre-skidding. 0-30%

Log length (m) A 2 3 5

3 4 5

B 2 3 4

Slope % 30-60% >60% Percentage of trees of remaining stand suffered damages per classes C A B C A B 1 3 5 1 5 8 2 6 9 4 8 11 4 8 11 6 9 14

were caused in ground slopes bigger than 60%, 35% of damages in slopes 30-60% and 17% in slopes 0-30%. The logs of 5 m long caused the 69% of damages during pre-skidding and the 56% during the major wood skidding. The logs of 4 m long caused the 34% of damages during the pre-skidding and 25% during the major skidding while the logs of 3 m long caused 20% of damages during the pre-skidding and 19% during the major wood skidding.

D a m a g e s (% ) o f tre es o f th e rem a in in g s ta m d

8 7 6 5

5

4

4

3

3

2 1 0 A

B

C

D am ag es (% ) o f treed o f th e rem ain in g stan d

Fig. 5 Damages (%) of trees of the remaining stand per class in connection to the length of logs during the major skidding of wood on the skidding track. 35 30 25 5

20

4

15

3

10 5 0 Α

Β

C

Slope 0-30%

Α

Β

C

Slope 30-60%

Α

Β

C 3 5 8

C

Slope >60%

Fig. 6 Damages (%) of trees of the remaining stand per class in connection to the length of logs and the slope of ground during the hauling of wood in the pre-skidding sites.

a rate of 25% to A class. The 48% of tree damages on the remaining stand

4. Conclusions From the above results we have come up with the following conclusions: (1) The percentage of damage in the remaining stand for the three classes (A, B, C) during the major skidding on the skidding track is smaller than the percentage of damage in the pre-skidding sites; (2) The largest percentage of damages belongs to B class followed by A class and C class; (3) The conditions of the ground slope affect proportionally the percentage of damages during the pre-skidding of wood. The 48% of tree damages on the remaining stand were caused in ground slopes bigger than 60%, 35% of damages in slopes 30-60% and 17% in slopes 0-30%; (4) The length of logs affects proportionally the size of damages of trees of the remaining stand as much as


during the pre-skidding as well as during the main wood skidding. From the above it is concluded that for the reduction of damages of the remaining stand at a rate of < 10% [10], the suitable means of wood skidding should be selected according to the conditions prevailing in each area whereas the operators must be trained for the correct use of machinery in order to protect the natural environment.

References [1]

[2] [3]

[4]

O. Sedlak, Forest opening-up and protection of natural environment, Österreichische Forstzeitung 7 (1993) 23-25. G. Becker, Forest opening-up control, Allgemeine Forst und Zeitung 9 (1995) 482-483. E. Karagiannis, P. Kararizos, Ecological impacts of the work mechanization in the wood-skidding in Greece, Czech Republik, 2001, pp. 97-107. H. Heinimann, Environmentally friendly forest

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opening-up-plan for organizing the analysis and utilization of wood in Greece, Schweizerische Zeitschrift fuer Forstwesen 145 (1994) 139-157. [5] K. Doukas, Planning of forest opening-up and wood transportation in Greece, Allgemeine Forst und Zeitung 12 (1994) 664-667. [6] K. Doukas, A. Akca, Research for the use modern photogrammetric methods in the trace and the surveying of forest cadastre, Forstarchiv 2 (1990) 77-80. [7] C. Stergiadis, K. Doukas, E. Karagiannis, P. Kararizos, The wood skidding in small distances with the drum Multi-KBF adjusted on a chainsaw, Scientific Annals of the School of Forestry and Natural Environment 27 (1984) 695-738. [8] A. Trzesniowski, The purpose of forest opening-up, Österreichische Forstzeitung 7 (1993) 5-7. [9] K. Tsatsarelis, Farming Tractors Teaching Book, School of Agriculture, Aristotle University of Thessaloniki, 2002. [10] H. Mayer, E. Ott, Mountain Sylviculture-forest Cultivation: Research for the Ecology of the Landscape and the Protection of the Environment, 2nd ed., Publisher Gustav Fischer, Stuttgart, 1991.


D DAVID

PUBLISHING

Evaluation of Social Environment Impact of Highway Construction Using Gray Matter-Element Information Entropy Model C.K. Hu Changsha Vocational Technology School of Information, Changsha 410116, China Received: April 14, 2011 / Accepted: July 4, 2011 / Published: December 20, 2011. Abstract: Due to the importance of the social environment impact of highway construction project, an advanced evaluation is required to incorporate situations such as uncertainty, incompatibility and less information. This paper proposes a gray matter-element evaluation model based on the information entropy. The model is developed by combining both quantitative and qualitative methods, using probability theory to convert quantitative index to qualitative index, and the weight of those indexes were determined through synthesised integral weighting method, integrating matter-element theory, grey theory, and information theory. The model is then applied to evaluate the impact of the social environmental impact of highway construction project which will provide support for decision makers. Cheng-Yu highway and Shen-Da highway were selected for model application, and good results were achieved similar to the real situation. Key words: Project evaluation, social environment, gray matter-element, assessment.

1. Introduction According to the international general operation and relational regulation in China, all of highway construction projects higher than level 2 should perform social environment impact assessment [1]. The current assessments in China emphasize on the natural environment impact assessment [2], leaving a blank on the social impact assessment. The later is also an important aspect of the overall assessment, especially for those projects receiving loan from the international financial organizations [3]. These projects address more on the importance and necessity of the projects’ impacts on the social environment. Therefore, it’s a new task to study the assessment of the highway construction project’s impact on the social environment. With an organic combination of the matter-element theory, gray theory and information Corresponding author: C.K. Hu, senior lecturer, main research fields: economic geography, logistics, environmental economics. E-mail: [email protected].

entropy theory, this paper developed a gray matter-element assessment model based on the information entropy theory [4]. The model is used to evaluate the degree of the project’s impact on the social environment, and provide support for decision makers.

2. Quantization of the Qualitative Indices It is necessary to create a comprehensive index system of the social environment assessment to assess the corresponding impact of highway construction project completely. This requires a large number of assessment indices which represent various aspects and multiple levels. According to the referring of the highway construction projects’ social environment impact, we establish a layered indices system as shown in Fig. 1. In view of due to the difficulty of directly quantizing the majority of social environment impact indices, and even some are impossible, this limits those indices to qualitative description and strained the qualitative

Evaluation of Social Environment Impact of Highway Construction Using Gray Matter-Element Information Entropy Model

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Enhance communication, produce area developing advantage. Advance iterature and teaching, science and technology, sanitation construction. Improve the convenience, comfortability and safety of the traffic. Social development impact Promote the social stability and solidification, national unity and defence. Influence the customs and religious beliefs of the areas along the line. Assessment on the social environment impact

Influence the historic culture, relics and sites. Change the industrial structure. Adjust the resource exploitation and utility. Develop and add value to the land. Economic exploitation impact

Accelerate the population movement. Improve the quality of living. Increase employment, balance income distribution. Improve the development of the commerce, tourism, service business. Optimize the road transport network efficiency and alter the structure.

Traffic environment impact Optimize the integrated transport network efficiency. Promote the external trade development, foreign investment. External links impact Promote the foreign exchange, international prestige.

Fig. 1 Indices system of the social environment assessment of the highway construction project.

description and summarization of summarization. It’s a pre-requestict to present some relational quantitative computation to provide an intuitionistic and profound assessment result. So, we should try every shift available to seek for a feasible quantitative computation method in the practical business. In the absence of a direct and effective computational method, we can resort to use the expert advice and scoring method, utilize apply the probability theory to quantize the identical qualitative index according to the number of score given from experts [5, 6]. Its specific criteria are shown in Table 1. The following is an example of the degree definition of the impact on the regional development. Assume that the value of Li = (1, 2,…, 5) is more objective, it can be regarded that it follows the normal distribution N (0, 1). As a result, the comment i (i = 1, 2,…, 5) reflects the evaluation degree on different evaluation indices given by Li = (i = 1, 2,…, 5) experts.

Li = (i = 1, 2,…, 5) ranks i th among all comments, i.e, there are i/5 comments less than that, using Ti = (i = 1, 2, …, 5) denoting the i / 5 of the normal distribution N (0, 1), expressed as follow equation:

i P ( Li < Ti ) = (i = 1,2,3,4) 5

(1)

Then Ti = (i = 1, 2, …, 5) divide the whole number axis (−∞,+∞) into 5 segments. It’s obvious that (i = 1, 2, …, 5) represents the corresponding value of Li = (i = 1, 2, …, 5) which falls into the interval of (Ti −1 , Ti ) . By selecting the interval median as

a

representative value, then Li = (i = 1, 2,…, 5) satisfies: P( L < Li ) =

i − 1 1 1 i − 0.5 + × = (i = 1,2, L,5) 5 2 5 5 5

i − 0.5 Li (i = 1,2,L,5) (3) 5 i=1 5

Quantitive value＝∑P(L < Li )Li = ∑ i =1

(2)

Where L obeys N (0, 1) normal distribution.

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Table 1 Evaluation criterion of the index of region development impact degree. Evaluation index Degree of the impact on regional development Number of experts

Comment Very small L1

Small L2

Ordinary L3

Large L4

Very large L5

Li (i = 1, 2, …, 5) represents the number of experts comment equally on some identical qualitative index. n

3. Weights of Assessment Indices In order to determine the index weights of assessment factors more objectively and reasonably, we adopt synthesised integral weighting method, which is established by combining of the subjective weighting method based on the “function motivation” principle and objective weight based on the “difference motivation” principle. The subjective weighting method, based on the “function motivation” principle, is a kind of “seeking common ground while reserving differences on minor ones” approach, and it determines the weights according to the assessment of the relative importance of indices. While the fundamental idea of “difference motivation” principle-based objective weighting method is that the original information for weighting should come from the objective environment directly, and the weights should be a measurement for both the variance degree of each index in the collectivity and other index impact degree. These weights are determined by the information quantity provided by each index.

k2 =

m

∑∑ q i =1 j =1

n

m

∑∑ p i =1 j =1

j

xij

n

j

m

xij + ∑∑ q j xij

> 0;

i =1 j =1

k1 + k 2 = 1

4. Evaluation Methods 4.1 Information Entropy Assume

that

X

is

a

source

which

{a1 , a 2 ,L , a n } with the corresponding probability set P = { p1 , p 2 , L , p n } , where ai is the symbol that can be produced by the source and pi is the probability of ai . The produces n symbols

appearance of each symbol from the source is uncertain. The amount of uncertainty is relative within the corresponding probability set. The information entropy is used to quantitatively describe the uncertainty: n

H ( x ) = − k ∑ p i ln p i

(5)

i =1

4.2 Analysis on the Impact Measurement

Assume that p j , q j are two index weights derived from the “difference motivation” principle and

Due to the coexistence of quantitative indices and

“function motivation” principle, respectively. Then the

many difficultly quantized indices in the assessment

final compositive weights which reflect the integration

index system of the social environment impact from

property of both the subjective and objective

highway construction project, the system is a typical

information could be described as follow:

gray system. The impact measurement of the gray

w j = k1 p j + k 2 q j

(4)

where

situation decision approach based on the gray system theory can be used to analyze such system.

n

k1 =

m

p

∑∑ p j xij

Let p denote the target, xij is the sample of project

i =1 j =1

n

m

∑∑ p i =1 j =1

n

j

m

xij + ∑∑ q j xij i =1 j =1

> 0;

S ij under the target of p , T is the unified effect p p measure transform, u ij is the effect measure of xij , then,


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⎧ xijp μ ijp is the upper bound effect measure when p is the maximum target. ⎪ p max max x ij ⎪ i j ⎪ p xij ⎪ (6) μ ijp is the lower bound effect measure when p is the maximum target. T ( xijp ) = μ ijp = ⎨ p min xij ⎪ min i j ⎪ p ⎪ min{ xij , x (0)} p ⎪ max{ x p , x (0)} μ ij is the moderate effect measure when p is the maximum target. ij ⎩ where x ( 0 ) 2 = 1 n

n

∑x j =1

2 ij

The compound matter-element with two layers weights can be described as follow:

.

⎡ C11 C12 L C1p C21 C22 L C2p L Cn1 Cn2 L Cnp⎤ (9) Rω=⎢ ⎥ ⎣ωik ω11 ω12 L ω1p ω21 ω22 L ω2p L ωn1 ωn2 L ωnp⎦

4.3 Analysis on the Gray Matter-Element Given the name N of something, v is the value

Where C ik denotes the k th secondary characteristic

on characteristic c, the ordered ternary R = ( N , c, v)

of the first matter’s i th primary characteristic, its

used to describe the matter is called elemental matter or

corresponding

~ matter-element in short. Let R represent gray matter-element, M denote the matter, C mean its characteristic, and u (x) stand for the effect measure of the value x corresponding with characteristic C ,

weights

are

represented

by

ω ik (i = 1,2,L, n; k = 1,2,L, p) . 5. Establish the Model Combining

factors

such

as

uncertainty,

incompatibility and less information, and using the

then, ~

⎡

R = ⎢ ⎣C

M ⎤ μ ( x ) ⎥⎦

(7)

principle of information entropy theory, the assessment model is established. The adopted operation mode (*)

If there are m matters that can be described by n

is addition-by-first-multiplation, denoted as M (•,+ )

common characteristics C1, C2, … ,Cn and the

in short. All the weights in this mode are taken part in

corresponding effect measures u(i1), u(i2), …, u(xmi)

the summation operation, and this requiresn that the

(i=1, 2, … , m), then these m matters are called n-dimension compound gray matter-element, denoted

~

as Rmn . Furthermore, let M j ( j = 1,2,L, m) represent the j th matter, C i be the i th characteristic of the

j th matter, u ( x ji ) denote the effect measure on the value of x ji ( j = 1,2,L, m; i = 1,2,L, n) corresponding with the i h characteristic of the j th matter, then we

weights should be normalized, that is

∑

i =1

ω

i

= 1

.

And then, the result correlation includes the effect of all factors, reflecting on the comprehensive evaluation in numeric. Under the indices system of the social environment assessment of highway construction project, the first level index includes 4 factors, i.e, the impacts on social

have:

M1 M2 ⎡ ⎢C μ( x ) μ ( x ) 11 21 ⎢ 1 ~ ⎢ R mn = C2 μ( x12 ) μ( x22 ) ⎢ M M ⎢M ⎢⎣Cn μ( x1n ) μ( x2n )

L Mm ⎤ L μ( xm1 ) ⎥⎥ L μ( xm2 )L⎥ (8) ⎥ M M ⎥ L μ( xmn ) ⎥⎦

It’s often that each characteristic of matters has multiple layers, so does the corresponding weights.

development,

economic

exploitation,

traffic

environment, external links, denoted as C i . The assessment model has m referred the comparation items, including some to be assessed items. Then C i denotes the i th index of the first level of the j th item. Each first level index includes p different second level indices, denoted as C ik . That is, C ik represents

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the k th second level index of the i th first level index of the j th item. x jik is the corresponding value

P(ωik μ jik ) =

of C ik , which is denoted by effect measure u jik . And hence, the n-dimension compound gray matter-element of the m assessment items could be described as following,

⎡ ⎢C ⎢ 11 ⎢ C12 ⎢ ⎢ M ⎢ C1 p ⎢ ⎢ C 21 ⎢C 22 =⎢ ⎢ M ⎢C ⎢ 2p ⎢ M ⎢ ⎢ C n1 ⎢C n2 ⎢ ⎢ M ⎢C ⎣ np

Mm ⎤ μ 111 μ 211 μ m11 ⎥⎥ μ 112 μ 212 L μ m12 ⎥ ⎥ M M M M ⎥ μ 11 p μ 21 p L μ m1 p ⎥ ⎥ μ 121 μ 221 L μ m 21 ⎥ μ 122 μ 222 L μ m 22 ⎥ (10) ~ ⎥ R mn M M M M ⎥ μ 12 p μ 22 p L μ m 2 p ⎥ ⎥ M M M M ⎥ ⎥ μ 1n1 μ 2 n1 L μ mn 1 ⎥ μ 1n 2 μ 2 n 2 L μ mn 2 ⎥ ⎥ M M M M ⎥ μ 1np μ 2 np L μ mnp ⎥⎦ Where, μ jik ( j = 1,2,L, m; i = 1,2,Ln; k = 1,2,L p) denotes the effect measure of the k th second level index of the i th first level index of the j th item. M1

L L

M2

The compound probability matter-element and compound self-information gray matter-element of the

m schemes, assessment and optimization can be constructed through Eqs. (9) and (10) which are

~

denoted as Rmp and Rmf , respectively. Then we have the following results: C11 C12 ⎡ ⎢P(ω μ ) P(ω μ ) P(ω μ ) 11 111 12 112 ⎢ ik 1ik Rmp =⎢P(ωikμ2ik) P(ω11μ211) P(ω12μ212) ⎢ M M ⎢ M ⎢P(ωikμmik) P(ω11μm11) P(ω12μm12) ⎣ L

C2 p

L

Cn1

L

C1p

C21

L P(ω1pμ11p) P(ω21μ121) P(ω22μ122) L P(ω1pμ21p) P(ω21μ221) P(ω22μ222) M M M M L P(ω1pμm1p) P(ω21μm21) P(ω22μm22) Cn2

L

L P(ω2 p μ12 p ) L P(ωn1μ1n1 ) P(ωn2 μ1n2 ) L L P(ω2 p μ22 p ) L P(ωn1μ2n1 ) P(ωn2 μ2n2 ) L L M L M M L L P(ω2 p μm2 p ) L P(ωn1μmn1 ) P(ωn2 μmn2 ) L

Where,

C22

⎤ P(ωnp μ1np ) ⎥⎥ (11) P(ωnp μ2np ) ⎥ ⎥ M ⎥ P(ωnp μmnp )⎥⎦ Cnp

ωik μ jik

∑∑ω μ i =1 k =1

⎡ ⎢C ⎢ 11 ⎢C12 ⎢ ⎢ M ⎢C1p ⎢ ⎢C21 ~ ⎢⎢C22 R mf = ⎢ M ⎢C ⎢ 2p ⎢ M ⎢ ⎢Cn1 ⎢Cn2 ⎢ ⎢ M ⎢C ⎣ np

( j = 1,2,L, m)

p

n

M1

ik

jik

⎤ − logP(ω11μ211) L − logP(ω11μm11) ⎥⎥ − logP(ω12μ212) L − logP(ω21μm12) ⎥ ⎥ M M M ⎥ (13) − logP(ω1p μ21p ) L − logP(ω1p μm1p ) ⎥ ⎥ − logP(ω21μ221) L − logP(ω21μm21) ⎥ − logP(ω22μ222) L − logP(ω22μm22) ⎥ ⎥ M M M ⎥ − logP(ω2 p μ22p ) L − logP(ω2 p μm2 p )⎥ ⎥ ⎥ M M M ⎥ − logP(ωn1μ2n1 ) L − logP(ωn1μmn1 ) ⎥ − logP(ωn2 μ2n2 ) L − logP(ωn2 μmn2 ) ⎥ ⎥ M M M ⎥ − logP(ωnpμ2np ) L − logP(ωnpμmnp) ⎥⎦ M2

− logP(ω11μ111) − logP(ω12μ112) M

− logP(ω1p μ11p ) − logP(ω21μ121) − logP(ω22μ122) M

− logP(ω2 p μ12p ) M − logP(ωn1μ1n1 )

− logP(ωn2 μ1n2 ) M − logP(ωnpμ1np )

(12)

L

Mm

Substituting Eqs. (12) and (13) into the following one, we derive

~

⎡

R H = R mp *R mf = ⎢ H ⎣

j

M1 M2 L Mm ⎤ H1 H2 L Hm ⎥⎦

(14)

Where n

p

H j = −∑∑P(ωik μ jik ) logP(ωik μ jik（ ) j = 1,2,L, m) , i=1 k=1

and the * denotes the addition-by-first-multiplation operation, H j represents the information entropy of the j th evaluation item. For the decided items, we choose the optimized threshold as the scale of the optimized schemes, denoted as λ . From the rule of optimization, we can get,

λ = H min + 0.618( H max − H min )

(15)

From the final computation result, we can then do some optimized selection among the H j that the value is large than

λ and sorted in descending.

6. Applications Based on the above analysis, it’s obvious that the model can reflect the decision function when the comparision is performed between the information


entropy of the future project and the constructed project to decide whether the previous one should be constructed or not. On the other hand, if all of the evaluated projects are the constructed project, then the model reflects some post-evaluation function. The information entropy-based gray matter-element assessment model is then applied to the the Cheng-Yu highway and Shen-Da highway projects to inspect the impact of the highway construction project on social environment. The detail of the final assessment is shown in Fig. 2. From Fig. 2, we know that both of Cheng-Yu highway and Shen-Da highway have generated obvious social impact, and the impact on the social environment of the later is higher than the preceding. While both of these two highway projects have much better impact on the social development and economic exploitation, they have less effect on the traffic environment external links. This means that there are some things to be improved on these two aspects for the highway construction project in China. In addition, for the traffic environment, due to the fact that Shen-Da highway is located along the coast, and the Cheng-Yu highway is located in the mountain, the former is better than the other. For the external links, the previous 22 1 1.8 .8

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result still holds. Once again, this is related with the locations of the highway. As Cheng-Yu expressway locates in south-west China, there are some disadvantages in foreign investment and external trades when compared with the areas along the coast.

7. Conclusion (1) The assessment of the impact on social environment is limited to the quantitative analysis in the past. To get a quantitative assessment result, this paper utilizes the median principle of the probability theory to convert the quantitative index to the qualitative index. This is achieved by first conducting the experts’ scoring evaluation on the qualitative index, and then calculating the number of experts under the condition of different comments, formulated in the form of probability. (2) The index weights are determined by the synthesized integration weighting method, established by the combination of the subjective weighting method based on the “function motivation” principle, and objective weight based on the “difference motivation” principle. The subjective weighting addresses the importance of the indices and the objective weighting addresses their information quantity. This will

CCheng h e n g –Yu - Y uhighway highway SShen h e n –Da - D ahighway highway

1 1.6 .6 11.4 .4 1 1.2 .2

11 0 0.8 .8 0 0.6 .6 00.4 .4 0 0.2 .2

00 Social

Economic

Traffic

External

Comprehensive

development

exploitation

environment

links

evaluation

Fig. 2 The detail of the final assessment of Cheng-Yu highway and Shen-Da highway projects.

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guarantee the final weighting to be more objective and reasonable. (3) There are intrinsic strong generality and objectivity when applying the information entropy-based gray matter-element evaluation method to highway construction projects to assess and analyze their impacts on the social environment. Combining those factors such as uncertainty, incompatibility and less information, this assessment approach is more scientific and reliable.

[2]

[3]

[4]

[5]

References [1]

Transportation Research Board, Guidebook for Assessing the Social and Economic Effects of Transportation Projects, National Academy Press, Washington D.C.,

[6]

2001. S.X. Yu, The research on analysis and evaluation method of the social environment of the highway construction project, Changsha University of Science and Technology, Changsha, 2005. X.L. Dong, Y.S. Zheng, Investigation and analysis for social environment influence of the region along the highway, Journal of Xi’an Highway University 19 (1999) 12-14. J. Xia, B.Q. Hu, A grey system model for predicting trend change of urban waste water load, Environmental Hydrology 5 (1997) 102-134. L.M. Shi, D.C. Luo, The quantitative analysis for highway ecological environmental impact assessment, China Journal of Highway and Transport 11 (1998) 43-46. W.N. Yuan, Z. Ren, Integrated assessment of highway environmental impact, Journal of Xi’an Highway University 19 (1999) 22-25.


D DAVID

PUBLISHING

Hydrological Modeling in a Semi-Arid Catchment Using SWAT Model M. Mosbahi1, S. Benabdallah2 and M.R. Boussema1 1. Laboratory of Remote Sensing and Information System for Spatial Reference, National School of Engineers Tunis 1002, Tunisia 2. Center of Water Technologies, National Institute for Scientific and Technology Research, Soliman 8020, Tunisia Received: May 4, 2011 / Accepted: July 12, 2011 / Published: December 20, 2011. Abstract: In the field of the water resources, hydrologic models have been used to assess water quality performance of complex watersheds and river basins. Hydrologic models can provide essential information for making decisions on sustainable management system of water resources within watersheds. The main objective of this study was to validate the performance of the Soil and Water Assessment Tool (SWAT) and the feasibility of using this model as a simulator of runoff at a catchment scale in semi-arid area in Northwestern Tunisia. Calibration and validation of the model output were performed by comparing predicted runoff with corresponding measurements from the Sarrath outlet for the periods 1990-1995 for calibration and 2000-2005 for validation. The time series for the years 1996-1999 showed discrepancies between the measured rainfall and the observed runoff indicating errors due to either the observations or to a dysfunction in the equipments. Sensitivity analysis shows that sensitive parameters for the simulation of discharge include curve number, soil evaporation compensation factor, depth of water in shallow aquifer and slope of subbasin. Statistical comparisons between monthly simulated results and observed data for the calibration period gave a reasonable agreement with a coefficient of determination (R2) greater than 0.75 and Nash-Sutcliffe Coefficient (NSE) equal to 0.72. These values were respectively 0.70 and 0.64 for validation period. Overall, the SWAT model has the capability to predict runoff within a complex semi-arid catchment. Key words: Semi-arid catchment, SWAT model, runoff.

1. Introduction Water becomes a precious natural resource of which good management leads to a long-term development and represents therefore a challenge for the demographic evolution in particular for semi-arid regions. Hydrologic models are of a major importance for better understanding of various hydrologic processes and developing new or improving management strategies. The Soil and Water Assessment Tool (SWAT) is a widely applied watershed simulation model and has been extensively used by hydrologists for watershed hydrology related issues and water quality [1-6]. The model was widely used to evaluate the impact of climate, land use, and Corresponding author: M. Mosbahi, assistant, Ph.D. student., main research fields: hydrology, hydrological modeling. E-mail: [email protected].

land management decisions on catchment dynamics [5-7] and to predict sediment loads at different catchment scales [8-10]. In Tunisia, the model was applied at a large scale on the Medjerda Catchment [11]. In this study the application of SWAT evaluated the potential hydrological and water quality impacts of land management scenarios. It was found that the model represented well the hydrological cycle despite the fact that hill dams were not simulated. Ouessar et al. [12] applied an adjusted version of SWAT model to a 270 km2 catchment located in southeast Tunisia. The simulated runoff showed that the calibrated model reproduced the observed events reasonably well despite the low density of the raingauge network and the possible measurements inaccuracies in runoff.

Hydrological Modeling in a Semi-Arid Catchment Using SWAT Model

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In view of this, the main objective of this study is to better understand how the hydrologic model (SWAT) could simulate water discharge reasonably well in the Sarrath river catchment, part of the large Tunisian Medjerda catchment.

2. SWAT Model Description SWAT is a hydrologic/water quality model developed by the United States Department of Agriculture-Agricultural

Research

Service

(USDA–ARS) [13, 14]. The main objective of SWAT is to predict the impact of agricultural or land management on water, sediment and agricultural chemical yields in ungauged basins. The present study focuses solely on the sediment component of the model. The model is a continuous-time, spatially distributed simulator of the hydrologic cycle and agricultural pollutant transport at a catchment scale. It runs on a daily time step. Major model components are hydrology, weather, erosion and sediment transport, soil temperature, crop growth, nutrients, pesticides, and agricultural management [15]. The hydrological component of SWAT is based on the following water balance equation (Eq. (1)):

SWt = SW0 + ∑(Rday − Qsurf − ETi −Wseepi− Qgw) (1) t

i=1

Where: SWt = the final soil water content (mm); SW0 = the initial soil water content on day I (mm); t = the time (days); Rday = the precipitation on day i (mm); Qsurf = the surface runoff on day i (mm); ETi = the evapotranspiration on day i (mm); Wseep i = the amount of water entering the vadose zone from the soil profile on day i (soil interflow) (mm); Qgw = the amount of return flow on day i (mm). Soil interflow is calculated by the kinematic storage model, which takes account of soil hydrological conductivity, topographical slope and the temporal and

spatial change of soil moisture. Lateral subsurface flow in the soil profile is calculated simultaneously with percolation. Ground water flow contribution to total stream flow is simulated by routing shallow aquifer storage component to the stream [13]. Surface runoff volume from daily rainfall is predicted with the modified SCS curve number method. The peak runoff rate is calculated according to the rational formula. Thus, runoff is reduced by channel transmission losses that infiltrate to an underlying aquifer. Evaporation of soil water and transpiration by plants are evaluated as functions of potential evaporation and plant leaf area. The potential evapotranspiration (PET) can be simulated with three methods in the study [16-18], the Hargreaves equation based on daily temperatures was used. Soil erosion and sediment caused by rainfall and runoff are estimated with the Modified Universal Soil Loss Equation (MUSLE) [19] for each sub-catchment (Eq. (2)):

sed = 11.8× (Qsurf ⋅ qpeak ⋅ areahru )

0.56

⋅ K ⋅ P ⋅ C ⋅ LS

(2)

Where: sed = the soil erosion load (metric tons); Qsurf = the surface runoff volume (mm H2O/ha); qpeak = the peak runoff rate (m3/s); areahru = the HRU area (ha); K = the soil erodibility factor; C = the cover and management factor; P = the support practice factor; LS = the topographic factor. In SWAT, a catchment is divided into multiple sub-catchments which are then divided into units of unique soil/land use characteristics called hydrological response units (HRUs). These HRUs are defined as homogeneous spatial units characterized by similar geomorphologic and hydrological properties [20]. In SWAT, HRUs are composed of a unique combination of homogeneous soil properties, land use and topography.


3. Study Area and Model Input Data The Sarrath river catchment is located in the north-west of Tunisia; its river originates in the semi-arid Atlas Mountains of eastern Algeria and drains an area of 1,491 km². The elevation ranges from 573 to 1,350 m and the slope steepness range between 3% to 72 % (Fig. 1). This region is part of the large Tunisian Medjerda catchment (24,000 km²) which is the principal watercourse and constitutes the water supply for more than half of the Tunisian population. Most of the catchment area is poorly covered with vegetation with the exception of some degraded forests and dense brushes on hilly areas. Major crops grown in the catchment are corn representing 31% of the total area, tree cultivation covering only almost 4% of the whole. The rest of the catchment consists of pasture (9%), uncovered land (8%) and husbandry (4%). The area under study lies in the sub-humid to Mediterranean humid bio-climatic region. It is characterized with an extreme variability in annual and inter-annual rainfall, in winter; the rain is usually of a frontal type and originates on the Mediterranean. In Tunisia, the rainy season extends from September to May with intense precipitations in September, October

Fig. 1 Study site location and the rain gauge network.

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and February. The mean annual rainfall for the period 1985-2005 is 350 mm with a standard deviation of 134.5 mm and a variation coefficient ranging between 0.32 and 0.47. The average temperature ranges from 4 to 28 °C. July is the hottest month with maximum monthly temperatures values between 19 and 28 °C. The coldest month is usually January with maximum monthly temperatures between 4 and 10 °C. The major soil types found in the Sarrath river catchment include calcareous brown soils, fluviosols and vertisols. Spatial data used in the study were derived using the SWAT Arcview Interface which provides a graphical support to the desegregation scheme and allows the construction of the model input from digital maps. The basic data sets required to develop the model input are: topography, land use, soil and climatic data. A digital elevation model (DEM) with a scale of 1:50,000 was generated using contours lines created for the purpose of this study from national topographic maps. The cell resolution with an interval of 50 m was used to generate the derived physical characteristics of the catchment. The soil and land use layers were obtained from the Soil and Water Conservation Agency. They were produced from Landsat Thematic Mapper images and from soil maps. Soil properties were obtained from Soil

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Database created by the Soil and Agriculture Land Authority. A GIS ArcView was used for generating the catchment and sub-catchments boundaries, drainage networks, slope, soil and land occupations layers from topography maps and Landsat images at a scale of 1:50000. The meteorological data during 1990-2005 which include maximum and minimum temperature were collected for two weather stations in and near the Sarrath catchment, from the National Meteorological Institute. Daily precipitations are gathered for twelve rain gauges stations over the same period from the National Water Authority.

4. Result Analysis and Discussion A river basin can be divided into sub-basins by discretization schemes. In the present study, the study area was subdivided into natural sub-catchments to preserve the natural flow paths, boundaries and channels for realistic routing of water. According to the natural river network, the topography of the basin, and the distribution of rainfall stations, the catchment was divided into 27 sub-catchments, as shown in Fig. 2. In order to get a reasonable resolution of soil properties, land use and management practices, these sub-catchments were further divided into a total of 273 discrete computational units called Hydrologic Response Units (HRUs).

Fig. 2 Spatial delineation of the catchment.

The simulation of surface runoff in the Sarrath catchment was carried out from 1985 to 2005. Measured runoff values at the outlet were used for monthly calibration purposes. For many years, the available data doesn’t cover the whole simulation period of 21 years. Thus, the time series were split into 5 years of warm up period to initialize the model runs, followed by a five years period for model calibration. The time series for the years 1996-1999 showed discrepancies between the measured rainfall and the observed runoff indicating errors due to either the observations or to a dysfunction in the equipments. The last period (2000-2005) is used for validation purposes. Fig. 3 illustrates a comparison of measured and simulated monthly discharge values at the Sarrath outlet over the period 1990-2005. In general, simulated runoff follows a similar trend to that of measured one, timings of occurrence of the peaks for both observed and simulated runoff matched well. In most cases, the order of magnitude of the flood peaks and recession curves is in reasonably good agreement, but in detail, flood are not well characterized, some peak flow events are not correctly represented. Since SWAT model has a large number of parameters, a sensitivity analysis was first conducted to identify the set of parameters that have the most influence on simulated runoff. Then, a calibration compares simulated results and measured runoff by


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Rainfall (mm)

MISSING RUNOFF

Fig. 3 Measured and simulated runoff at the Sarrath river catchment (1990-2005).

adjusting the sensitive parameters validation analyzes results.

and

finally

4.1 Model Sensitivity Analysis Sensitivity analysis was performed to evaluate the effect of parameters on the SWAT model runoff. On the basis of sensitivity analysis, it was found that the most sensitive parameter for this case study is the curve number (CN), which contributes directly to surface runoff generation, followed by the evaporation soil compensation factor (ESCO), the depth of water in shallow aquifer (GWQMN) and the slope of subbasin (SLSUBBSN) (Table 1). It is interesting to note that sensitive parameters are different for different catchments. These parameters were adjusted during the model calibration, this procedure was continued until predicted and measured discharges were in reasonable agreement. 4.2 Model Calibration and Validation The monthly calibration and validation of the SWAT model for runoff were performed after conducting sensitivity analysis. The calibrated values for the most

sensitive parameters are presented in Table 1. Goodness-of-fit measures were evaluated to test the accuracy of prediction; these measures were the Nash-Sutcliffe efficiency [21] and the coefficient of correlation (R2). Fig. 4 presents a comparison between the measured and simulated monthly runoff for the calibrated model. Both the calibration and validation graphs show good similarity between measured and simulated runoff with an NSE = 0.72 and R2 greater than 0.75 for calibration and NSE = 0.64 and R2 = 0.70 for validation. Most of observed runoff events are replicated by SWAT, although the SWAT model appears to have a slight tendency to over-predict small events (< 4 m3/s) and to under-predict some peak values. Some of these discrepancies remained mainly due to uncertainties in the observed runoff data and errors involved with the linear interpolation of rainfall data. To better represent calibrated runoff, a wet year (2003) and dry year (1993) (without gaps in runoff measurements and with complete rainfall datasets) were chosen. Fig. 5 showed that an improved fit was obtained in 2003, the predicted monthly runoff

Table 1 Ranges and values of major sensitive parameters used in this study. Symbol CN2 ESCO GWQMN SLSUBBSN

Description SCS runoff curve number for moisture condition Soil evaporation compensation factor Threshold depth in the shallow aquifer for flow (mm) Average slope length (m)

Min 35 0 0 10

Max 98 1 5000 150

Process Surface runoff Evapotranspiration Groundwater Surface runoff


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(a)

(b)

Fig. 4 Comparison between measured and simulated calibrated monthly runoff for (a) model calibration and (b) model validation.

(b) Run off (m3/s)

(a)

Fig. 5 Comparison between measured and simulated calibrated monthly runoff for (a) a dry year and (b) a wet year.

accurately reflected the observed values as indicated by NSE equal to 0.85. The predicted monthly runoff for the dry year was less accurate with an NSE of 0.55.

simulating a large complex system or catchment.

References [1]

5. Conclusion The SWAT model is a very useful tool for investigating alternative watershed management strategies on watershed hydrologic response. However, calibration and validation of the model is a key factor in reducing uncertainty. The study showed that the SWAT model could simulate runoff accurately well for a semi-arid catchment. In most instances, simulated runoff is closer to the measured values with a Nash coefficient of 0.72 despite the different gaps and discrepancies between rainfall data and observed runoff. SWAT predictions were acceptable especially given the approximations and spatial variability involved in

[2]

[3]

[4]

[5]

R. Srinivasan, T.S. Ramanarayanan, J.G. Arnold, S.T. Bednarz, Large area hydrologic modeling and assessment part II: Model application, Journal of the American Water Resources Association 34 (1998) 91-101. K.C Abbaspour, J. Yang, I. Maximov, R. Siber, K. Bogner, J. Mieleitner, et al., Modeling hydrology and water quality in the pre-alpine/alpine Thur watershed using SWAT, Journal of Hydrology 333 (2007) 413-430. M. Jha, P.W. Gassman, J.G. Arnold, Water quality modeling for the Raccoon River watershed using SWAT2000, Transactions of the ASABE 50 (2) (2007) 479-493. Y. Zhang, J. Xia, T. Liang, Q. Shao, Impact of water projects on river flow regimes and water quality in Huai River basin, Water Resources Management 24 (2010) 889-908. V. Chaplot, Water and soil resources response to rising levels of atmospheric CO2 concentration and to changes in precipitation and air temperature, Journal of Hydrology


[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

337 (2007) 159-171. W. Cao, W.B. Bowden, T. Davie, A. Fenemor, Modelling impacts of land cover change on critical water resources in the motueka river catchment, New Zealand, Water Resources Management 23 (2009) 137-151. G. Ghaffari, S. Keesstra, J. Ghodousi, H. Ahmadi, SWAT-simulated hydrological impact of land-use change in the Zanjanrood Basin, Northwest Iran, Hydrological Process 24 (2010) 892-903. P.M. Ndomba, F.W. Mtalo, A. Killingtveit, A guided SWAT model application on sediment yield modeling in Pangani River basin: Lessons learnt, Journal of Urban and Environmental Engineering 22 (2008) 53-62. Z. Kliment, J. Kadlec, J. Langhammer, Evaluation of suspended load changes using AnnAGNPS and SWAT semi-empirical erosion models, Catena 73 (2008) 286-299. W. Ouyang, F. Hao, A.K. Skidmore, A.G. Toxopeus, Soil erosion and sediment yield and their relationships with vegetation cover in upper stream of the Yellow River, Science of the Total Environment 409 (2010) 396-403. F. Bouraoui, S. Benabdallah, A. Jrad, G. Bidoglio, Application of the SWAT model on the Medjerda river basin (Tunisia), Physics and Chemistry of the Earth 30 (2005) 497-507. M. Ouessar, A. Bruggeman, F. Abdelli, R.H. Mohtar, D. Gabriels, W.M. Cornelis, Modelling water-harvesting systems in the arid south of Tunisia using SWAT, Hydrology and Earth System Sciences 13 (2009) 2003-2021. J.G. Arnold, R. Srinivasan, R.S. Muttiah, J.R. Williams,

[14]

[15]

[16]

[17]

[18]

[19]

[20]

[21]

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Large area hydrologic modeling and assessment, Part I: Model development, Journal of the American Water Resources Association 34 (1998) 73-89. R. Srinivasan, S. Huisman, L. Breuer, European SWAT summer school 2004: User’s manuel, Institute of Landscape Ecology and Resources Management, Justus-Liebig-University Giessen, Belgium, 2004. S.L. Neitsch, J.G. Arnold, J.R. Kiniry, R. Srinivasan, J.R. Williams, Soil and Water Assessment Tool, The Oretical Documentation Version 2000, Grassland, Soil and Water Research Service, Temple, Texas, 2002. C.H.B. Priestley, R.J. Taylor, On the assessment of surface heat flux and evapotranspiration using large scale parameters, Monthly Weather Review 100 (1972) 81-92. J.L. Monteith, Evaporation and the Environment, The State and Movement of Water in Living Organisms, Cambridge University Press, Cambridge, 1965, pp. 205-234. G.H. Hargreaves, Z.A. Samani, Reference crop evapotranspiration from temperature, Applied Engineering in Agriculture 1 (1985) 96-99. J.R. Williams, H.D. Berndt, Sediment yield prediction based on watershed hydrology, Transactions of the ASAE 20 (1977) 1100-1104. K. Bongartz, Applying different spatial distribution and modeling concepts in three nested mesoscale catchments of Germany, Physics and Chemistry of the Earth 28 (2003) 1343-1349. J.E. Nash, J.E. Sutcliffe, River flow forecasting through conceptual models Part I: A discussion of principles, Journal of Hydrology 10 (1970) 282-290.


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Global Warming, Elites and Energy in Latin America: The Chilean Case C. Parker Institute for Advanced Studies, University of Santiago de Chile, Santiago de Chile 7500618, Chile Received: March 15, 2011 / Accepted: July 12, 2011 / Published: December 20, 2011. Abstract: Adaptation and mitigation measures and changes in production and consumption patterns are necessary to face the risks of the impacts of global warming. They imply large investments the costs of which companies and governments, in charge of elites are not always willing to endure. Changes in elites have a direct impact on public policy and environmental governance of societies. Are the new elites willing to change traditional patterns of energy consumption if the change could threaten investment and economic growth? Based on empirical research this paper analyzes the role of elites in a developing Latin American country (the Chilean case) in decisions adopted about the explanations of climate change and specially on the set of measures for adaptation and/or mitigation, focusing on the energy sector of the economy, one of the key sectors directly implied with the possibilities of reducing greenhouse gases emissions. Key words: Global warming, elites, energy, climate change, sustainable development, environmental governance.

1. Introduction

(GHG) emissions.

Global warming is affecting biodiversity and life forms on the planet and has clear economic and social consequences. The risk and vulnerability in an unequal world increases, and proposes to help mitigate the impact of these changes urges. Adaptation and mitigation measures and changes in production and consumption patterns are necessary. They imply large investments the costs of which companies and governments in charge of elites are not always willing to endure. This paper analyzes the role of elites in a developing Latin American country (the Chilean case in particular) in decisions adopted about the explanations of climate change (CC) and specially on the set of measures for adaptation and/or mitigation, focusing on the energy sector of the economy, a key element directly implied with the possibilities of reducing the greenhouse gases

1.1 Debate on Global Warming and Climate Change Scientific Knowledge

Corresponding author: C. Parker, professor, sociologist, Ph.D., main research fields: sociology of science and technology, sociology of sustainable development, sociology of culture. E-mail: [email protected].

The global network of scientists and research centers worldwide, with support of many governments, has generated a clear consensus on the conclusions of the IPCC [1] that CC is anthropogenic [2]. But such a conclusion is uncomfortable for both the highly industrialized countries (U.S., Europe and Japan), the new emerging powers (China, India, Brazil) as well as multinational industries related to production and consumption of carbon based energy, as multinational oil companies and automobile industries. On the other side the general accepted argument by environmental movements as well as Third World countries is that the highly industrialized countries must “pay the debt” by the so-called carbon footprints assuming that changes in climate are the result of years of pollution generated by the industrial mode of production with the use of conventional energy patterns. The position of the elites in peripheral developing

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Global Warming, Elites and Energy in Latin America: The Chilean Case

countries will be precisely determined by the fact that these countries do not feel responsible for the global environmental problems given the fact that the industrial production has been led by the industrialized West. The needs to promote economic growth within a highly competitive globalization world makes emerging countries (Brazil, Argentina, Chile) and other developing countries in Latin America view mitigation and adaptation measures to CC as less urgent. The implementation of them could eventually slow their economies towards growth. All this is particularly evident in terms of investment decisions in the energy sector in which the priorities are for power supply based mainly on coal-fired power plants over other alternatives such as biomass and clean renewable energy. The battle for legitimacy of the scientific knowledge of CC is more evident in industrialized countries and mainly in the USA. “Powerful industries affected by proposed climate crisis solutions have used all the political tools at their disposal in opposition” [3]. This opposition includes media campaigns, lobbying and generating pseudo scientific theories denying the scientific consensus. Despite the clarity of the conclusions of scientific knowledge the subject has turned controversial. The deniers seek to delegitimize the analysis of the scientists and tend to question the need for reduction measures of emission of GHGs. The controversy involves the power struggles within the ruling elite so that while there are interest groups that support the scientific discourse of the IPCC, others try to interfere with the dissemination of findings. Independent investigations have concluded that for the case of several U.S. government agencies they have not interfered with the conclusions of scientists but have hampered heavy public dissemination. They have partially censored analysis and conclusions, or diminished the mandatory nature of the impacts of CC [4]. Gore [5] in his famous report “An Inconvenient

Truth” states that since 1989 several representatives in Congress have set the issue of CC but not in proper terms for a change of attitude of the Congress. In his book, Choice et al [3] propose a set of suggestions to solve the urgent climate crisis. Conservatives oppose dealing with the challenge of CC as referred to as a covert form of bringing about change and engaging state interventionism. The scientific discourse is discredited as a way to disorient business and civic elites. A study on increasing public awareness of global warming in U.S. says: “Consciousness does not necessarily imply acceptance, though polls indicate that more than half of Americans believe climate change as real, there is still uncertainty widespread public about the extent to which human activities are involved, and how much CO2 emissions should be reduced” [6]. 1.2 The Need to Implement Serious Changes We are facing serious limits to growth of the capitalist economy based on “business as usual” and found on conventional carbon energy. According to estimates by the International Energy Agency [7], coal demand will grow between 2007 and 2030 by 53% and natural gas demand will grow by 42%. As global demand for electricity will grow by 76% between 2007 and 2030, it is estimated that demand will be mainly met by burning fossil fuels. Without a change in energy policy, the world is on track to global temperature increase up to 6 °C, with catastrophic consequences for our climate. For these reasons, the chief economist of the International Energy Agency said in November 2009 in Rome that “assuming climate change and increase energy security requires a massive decarbonization of the energy system. To limit the temperature rise of 2 ºC, it requires a huge reduction in emissions in all regions” [8]. The reduction of GHGs emissions involves several changes in the mode of production, services and transport. Changes imply large investments and costs


for companies and governments, so they are often not willing to endure. A change towards a free carbon footprints economy involves assessing investment in long terms. On the contrary, local business in a developing capitalist economy tends to maximize profits in the short term. A short-term logic of business local elites together with political elites (caught in democratic societies by the logic imposed by the political cycle of elections and electoral interests) make them lose sight of long term considerations. Latin America, although with a minor role in the generation of global GHGs, due to its lower participation in power generation by burning fossil fuels, however, is also called to revise its forms and modes of production in general, and power generation in particular, which involves considerations that cannot stay in short terms. In terms of generation of emissions by the use of fossil fuels, Latin America (included Chile) face two major challenges according to ECLAC [9]: (i) address the challenge of energy efficiency, facing the economic and population growth in the coming decades and (ii) “pointing for a competitive position in a new global low-carbon economic paradigm” [10]. Faced with the urgency of global warming, there are a set of measures and alternatives that have been tested in various industrialized and developing countries. But the measures so far seem to be ineffective in countering the real and increasing emission of CO2. The United Nations Environment Programme [11] supports the need to advance a “green economy” that is to advance to a “green industrial revolution”. This is a plan that encourages a new generation of assets such as ecosystems and renewable energy, products and services derived from biodiversity, green jobs, new technologies for handling chemicals and waste, climate change mitigation and “Green Cities” (buildings, structures and transportation systems safe for the environment). The effort of companies seeking to be socially

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responsible is focused on mitigating of GHG emissions, adapting to changing weather conditions and applying existing and innovative technology to improve energy efficiency. But still the main trend of public and private companies in Latin America is to promote changes, including green jobs, as a marginal solution. Employment is one of the main challenges facing the needed changes. Green jobs proposed by the International Labor Organization [12] aims to prevent unemployment. Promotion of green jobs has the advantage that achieves the goal of employment; it also fulfills the purpose of promoting sustainable development. A major difficulty to agree on effective measures that address deep global warming, which may affect the slow progress of green economy and jobs, is that as the economy is mainly supplied by fossil fuel, changing all the mode of production will undermine the goals that the current capitalist economy favors: the profitability of business and economic growth. 1.3 New Elites and the Environment in Latin America and Chile The BP oil spill in the Gulf of Mexico, in 2010, one of the most serious pollution phenomena known to date, has relocated once again in world public opinion the problematic links between multinational energy interests and environmental risks. This case has shown the importance of elites as a relevant social group in negotiation between business interests, state institutions and society. The growing relationship between the political field and the market (based on global economic transformations in Latin America and the world) has restructured economic and political elites that circle the exercise of power in the state. Currently the operation of the state apparatus is based on new forms of elites relationships, these elites being understood as those groups that “have the command of the major hierarchies and organizations of modern society: rule big business, govern the state machinery and demand

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prerogatives, direct the military organization, occupy the helm of the social structure ... ” [13]. For Van Dijk [14] the power of the elite can be defined in terms of the type or amount of control that they have on the actions and minds of others. According to this author business corporations occupy a prominent place in studies of elites, whether it is owners and managers, corporate elites are taking an increasing economic and financial power, manifested in the political, social and cultural arena. In Latin America the historically dependent development models based on the exploitation of natural resources or substituting industrialization were implemented by elite groups that dominated the state. Democratic transitions and the neo-liberal turn of the 1980s and 1990s brought new studies that considered new political, technocrats and business elites as the agents of change in the established order [15]. These changes in elites have an impact on public policy making and governance of corporations [16]. In fact Neo-liberal policies of the 1980s and 1990s brought new groups to political and economic power. The power of these groups goes beyond the economic sphere [17]. Indeed they have a vision of the country and themselves, and of the social relationships in various areas of society. These new business elites show some sensitivity for the environment, more for reasons of competitiveness and of exports to developed countries than anything else, but its policies toward the environment tend to focus on the free market, defense of private initiative and ownership and non-state intervention [18]. These new business and political elites currently in power in many Latin American countries have pledged to innovate in environmental policies, but there have been no fundamental changes in the mode of production and move towards a “sustainable and green” economy, except environmental legislation and certain norms on investment in regulatory terms. The remaining question is: To what extent the new elites which are strategic actors are truly imbued with

an awareness of CC and their alternative energy solutions point to a real reduction of GHGs and to production of energy with less carbon footprint?

2. Methods and Data This work builds on sociological research we are currently doing in Chile about the elites and their attitudes towards climate change. We consider the social and political context of the debate on CC and the issue of the new elites and their attitudes toward the environment in Latin America and Chile. Conclusions are drawn from the analysis of secondary sources about the recent evolution of official policies towards the environment in Chile and from the output of recent surveys and qualitative and quantitative data from Chile and elsewhere. Two surveys conducted by us in 2009 and 2010 in particular are analyzed in the next section of this paper. Pollution in Chile has been the most discussed by the media and opinion polls, but CC has attracted attention only in recent years. There have long been public surveys about pollution and environment civic awareness [19]. Regarding CC, the Institute of Political Ecology conducted a survey in five districts of Santiago de Chile, in 2008 (January). In this survey a majority of Santiago residents, 97% recognized the importance of the problem, 94% is aware that its effects are “serious” and 97% calls for “urgent measures” to cope with the consequences. However, they do little at home and in daily life to mitigate global warming, for example, 32.9% uses their car for transportation, 30% uses public transportation and only 1.4% uses the bike. The results of our research on science and technology within university students of 2006-2007 indicate a change in the collective representations to nature. Rapid development of S & T beyond its formidable achievements has triggered ecological problems [20] and impact on university students. Faced with the question: should human beings to dominate or coexist with nature? 86% of them are favorable to coexist in harmony with nature, leaving the premise of


the Enlightment that progress is the result of the better exploitation (via technology) of nature [21]. In the end of 2010 we conducted a random sample of undergraduate students of all the top and main universities in the country representing 60% of the universe of all university students in the Country. N = 1318. In this survey 94.5% said that human beings should seek to coexist with nature and only 5.5% prefer the option that humans should “dominate nature”. In 2008 we surveyed secondary and university students (representing five regions of the Country) and 87% of them claim that global warming is caused by GHGs and that they increase with the burning of fossil fuels. It appears that the level of information has declined over the years since the 2010 survey on undergraduate students in the country. Only 71.2% agree with the statement on global warming and 20.8% declared “not knowing”. For the general population in 2006, 75% of Chileans surveyed by the WVE (World Value Survey) [22] thought that global warming is a “very serious” problem and another 22% consider it serious. In the survey of university students in 2010, 81.4% declared the global warming issue as “very serious” and 16.9% “serious”. Chileans do not differ largely from a general trend among Latin Americans, according to the WVS (2006) that Argentines were more concerned (84%), Mexican and Uruguayan slightly lower (69%) and Brazilians lower (61%). The weird thing is that this trend is in contrast with countries like Germany where the authorities and elites have taken a series of environmental measures for several decades, and 49% of its citizens say that the issue of global warming is “very serious”. This difference of public opinion in central industrialized and developing peripheral countries seems to correspond to the relative position in the global system and the respective impact of CC in the production and energy system and economic and social issues.

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We read in a recent multi-country poll of the World Bank [23]: “The publics in most countries believed that scientists agree that climate change is an urgent problem which is understood well enough that action should be taken. Substantial majorities had this view in low-income countries, while majorities did not perceive this scientific consensus in Russia, the US, and Japan”. On the other hand, Chilean citizens, a trend shared with citizens of other countries in Latin America, say in 68% that they prefer to prioritize the environmental protection over economic growth increase in the country. And even 57% state that they are willing to sacrifice part of their income to support environmental measures. “Majorities in 14 countries were willing to pay between 1.0% and 0.5% of GDP per capita in higher prices resulting from steps taken against climate change. In nearly all countries, majorities supported key national steps to deal with climate change, even when the steps were described only in terms of costs, not benefits” [23]. About business elites we are carrying out an in-depth research. As a first step towards this social group and its representations of the CC and the global warming we conducted a preliminary survey to those attending the Seminar “Energy and Environment: A difficult equation for Latin America” held at the Institute for Advanced Studies in October 2009. Responses were from 70 people mostly consultants and professionals: 19 businessmen (mainly SMEs), 16 consultants, 16 students, 13 academics and 13 professional employees. The vast majority related to professions or occupations that are related to energy and/or the environment. The bias of this sample must be assed from a qualitative perspective. All of the interviewed are people who have an interest in the subject, they are in frequent contact with institutions and companies which carry out processes and/or projects related to energy. They are in methodological terms “qualified informants” of common businessmen practices.

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In an exploration on what can be called “elites of the future”, in the abovementioned university undergraduate students survey (2010) we have divided a sample of normal or common career students and another sample of top career students (ie occupations with social “distinction and prestige”, with a great cultural capital in Bourdieu’s terms) as lawyers, industrial engineers, business administrators and doctors who are the main occupations from where business and political elites are recruited in the country. The main results are analyzed in the next section of this paper.

3. Results 3.1 Recent Sociopolitical Setting: Environmental Concern in Chile

Growing

For several years in Chile as in many Latin American countries the environmental issue is of public concern. Foremost the environmental damage was accepted as a necessary evil but in the middle of the 1980s environmental problems worsened and the state should play a more active role. The Basic Law for the Environment was approved in 1994. In November 2009 after long negotiations an agreement was reached to co-laws between the executive and legislative branches creating a new institutional framework to regulate environmental protection in Chile, and among others, created the new Ministry of Environment. The CC in Chile Report of the Sustainable Development Council (a Presidential Advisory Council) posed in 2008 that mitigation and adaptation measures should be taken. But this report was not conducive to a decisive shift in the energy production. It promoted the search for energy efficiency and diversification of its matrix. Non conventional renewable energy systems, such as solar, wind, tidal, biomass and geothermal were mentioned but subordinated to the need of the country: first, to generate more energy to meet development needs and, second, to achieve greater energy autonomy. Therefore, the aim of reducing carbon emissions, challenge of CC,

is secondary and is diluted in a host of other priorities. For its part, in the same strategic logic, the National Energy Commission in its 2008 report favors the goal of supplying energy in order to encourage growth needs and investments ensuring competitiveness. Currently in the context of a right wing government, whose president, however, is at least in his discourse in favor of non-conventional renewable energies, there has been a whole controversy over the increase in new investments in coal based thermoelectric power plants. In August 2010 the President Piñera decided to stop the project “Barrancones”. The Thermoelectric Power Plant of 540 MW was 25 km from the Nature Sanctuary “Punta de Choros”, currently hosting 85% of Humboldt penguins in the world. The citizen and environmentalist mobilization and pressures, mostly by social networks were of such magnitude that the Government had to yield. However, the project continues and the company Suez Energy must find a new location for the installation of the coal power plant. A citizen posted on Twitter: “Chileans should be proud you fold the hand to the Government ... that is the way to defend our environment ..... No doubt that alternative energy sources like solar and wind energy are more expensive investment but in the long run they are cheaper because they are cleaner...”. The bottom line, as is evident, is not whether a polluting plant is located near a nature sanctuary but the mode of energy production, with more or less carbon footprints. For the authorities economic growth is a priority therefore it is needed to favor investments to increase energy sources, whether clean or not for citizenship the aim is to advance real change towards a green economy based on renewable energy sources. 3.2 Empirical Data from Surveys 3.2.1 Chilean Professional and Consultants Elites and CC The survey we carried on with a qualitative sample of SME businessmen, consultants, students, academics


and employees related to professions or occupations linked to energy and/or the environment sectors, professional and consultants that form a “qualified informants” sample evidence both awareness of the problem of CC and give us information about common business practices. Some 91% say that global warming is caused by GHGs being generated primarily by burning fossil fuels. 81.4% considered that the problem of global warming is “very serious”. In terms of priority options for the country, 43% choose to “protect the environment”; 17% choose to “generate economic growth and jobs” and 27% would prefer “both” alternatives at a time. Words are clear to a group that is involved in business but has mostly environmental awareness. Regarding their views of the reaction of the businessmen and institutions in face of the crisis of CC, we can say that there is a significant percentage (40%) claiming that the business elite in Chile has taken measures or will take them, but a third is critical. In fact, 10% said that the companies have recently significantly increased actions towards sustainability, 30% stated that they will increase the sustainability actions. However, another 30% believe that there have been no changes at all, while the 3.3% say that actions towards sustainability “have failed” and 26.7% say that they have no comments because of lack of information. Therefore, there is an account of a critical discourse that marks the deficiencies of businessmen and senior executives of the institutions in their responses to the challenges of the CC and sustainability. Finally, there is a clear awareness that businessmen should take the environmental issue. 93% said that the concept of “corporate social responsibility” must consider the environment. We note that we are here discussing the views of an elite group of advisors and consultants, not strategic actors themselves but influential on them. This group plays the role of mediator between strategic elites (businessmen or politicians) and the world of science

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and knowledge (Research, Development and Innovation). According to the issues raised by Van Dijk [14] although elites normally represent the upper ranks of the institutions or organizations, some as famous writers and movie stars can exert their influence through power resources, such as prestige, respect and admiration. In this case it is otherwise made up of elite scientists and professional elites, usually consultants of private or government enterprises often grouped in Think Tanks, or simply in small agencies or consulting firms. This is certainly a group of no less importance in the social construction of knowledge and the performative discourses of the elites and ultimately on the definition of public policy. In relation to alternative energies, this elite group strongly prefers measures that aim to reduce the burning of carbon and promote non conventional renewable energies. 60% of them “strongly agree” with the statement “the burning of fossil fuels must be drastically reduced” and 30% said they “agree”. Only 7% disagree. In relation to renewable energies the preferences go to wind energy with 69.7% followed by solar energy (64.3%) and tidal energy (43.5%). The preferences for geothermal energy are 36.9%, biomass 36.2% and finally there is the alternative of nuclear energy (20%). 3.2.2 “Future Elites” and CC Exploring what can be called “future elites”, in the undergraduate students survey (2010) we have mentioned there is a different pattern of responses coming from the common career students sample and the top career students sample these represent of future elites. The results on CC indicate that the top career students are relatively less inclined to accept the anthropogenic explanation of CC than their peers. Table 1 shows however that this trend is slight and not statistically significant. On the CC and its causes originating in the burning of fossil fuels top career students have relatively less

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information than their peers (see Table 2). Here also the differences are slight and not statistically significant. On global representations of the relationship between man and nature elite students tend to a less favorable vision for the coexistence of both and slightly more towards the idea of “dominating nature” (see Table 3). Here also the differences are slight, but the statistical significance of the Chi-square and contingency coefficient are relevant. Finally, compared to the alternatives of creating programs and incentives for entrepreneurs to invest in mitigation or adaptation to CC (see Table 4) top career students are more inclined than their peers in common careers.

As shown the evidence is statistically significant. These data about the future elites can be interpreted coarsely as there is only a slight difference between students from top careers and their peers of other careers. Notwithstanding, the elite student group shows a position with less knowledge about the causes of CC; a classical view about the need to exploit natural resources (regardless of ecosystems and environmental balance) and a more favorable position on measures for encouraging profitable investments for companies to assure mitigation and adaptation to CC. Yet the great majority is in favor of changes and supports measures to address the CC (see Table 5).

Table 1 Main cause of global warming. Q: You believe that the main cause of global warming of the earth in the last hundred and fifty years is? (Outputs in percentages) N = 1318. Type of university student Top careers Common careers Mean

A. Man’s own activity 43.7 46.9 46.1

B. Long natural climate cycles 4.8 4.0 4.2

A combination of A and B 50.5 47.1 47.9

Do not know

Total %

1.0 2.0 1.8

100 100 100

Chi-square = 2.915; df = 3; P value = 0.4048; C = 0.0472. Table 2 Knowledge of causes of global warming. Q: Global warming is caused mainly by the effect of GHGs from burning fossil fuels? (Outputs in percentages) N = 1318. Type of university student Top careers Common careers Mean

Yes 69.1 71.9 71.2

No 9.3 7.5 7.9

Do not know 21.5 20.6 20.8

Total % 100 100 100

Chi-square = 1.325; df =2; P value = 0.5153; C = 0.0319. Table 3 Representation of relationship between humans and nature. Q: Which is your option in the following dilemma: Human beings should “dominate nature” or human beings should “coexist with nature”. (Outputs in percentages) N = 1318. Type of university student Dominate Top careers Common careers Mean

2.0 1.2 1.4

More or less dominate 6.9 3.1 4.0

More or less coexist 24.4 20.0 21.1

Coexist

Total %

66.7 75.6 73.5

100 100 100

Chi-square = 13.9282; df = 3; P value = 0.0030; C = 0.1042. Table 4 Opinion about investing in mitigation and adaptation to climate change. Q: Programs and incentives should be created for businessmen for investing in mitigation and adaptation to CC in Chile. (Outputs in percentages) N= 1318. Type of university student Top careers Common careers Mean

Strongly agree 74.5 70.6 71.6

Agree 21.0 25.8 24.6

Chi-square = 10.6952; df = 3; P value = 0.0134934; C = 0.0899.

Disagree 4.5 2.3 2.8

Strongly disagree 0.0 1.3 1.0

Total % 100 100 100


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Table 5 Opinion about the need to reduce burning of fossil fuels. Q: The burning of fossil fuels must be drastically reduced. (Outputs in percentages) N = 1318. Type of university student Top careers Common careers Mean

Strongly agree 51.0 52.8 52.4

Agree 45.2 42.4 43.1

Disagree 2.9 3.7 3.5

Strongly disagree 1.0 1.1 1.1

Total % 100 100 100

Chi-square = 1.1477; df = 3 ; P value = 0.7655; C = 0.0295.

So much so that an overwhelming majority of elite students (96%), without much difference with their peers from other careers as shown in the table, says drastic measures must be taken to curb the burning of fossil fuels, the main cause of GHG emission and CC.

4. Discussion Despite the greater sensitivity to the environment and the fact that during the past two decades environmental and ecological awareness has increased in all ideological spectra [18], despite increasing sympathy for environmental and ecological movements official discourse about the CC is limited and gives secondary importance to the challenges of global warming. The main official government policies favors the goal of supplying energy in order to encourage growth needs and investments ensuring competitiveness. Environmental considerations are present but are subordinate to the primary objectives of economic growth so that the shift in the modes of production to less carbon emissions is not the first priority. Chilean position in the international system as a peripheral country is taken into account by the discourses of political elites and technocrats that have produced these reports. They try to justify not favoring the use of non-conventional renewable energies. It is recognized that the total emissions impact of Chile in the world is marginal (about 0.3% of total global emissions), but stands next line the report acknowledges that GHGs emissions will increase as new coal based power plants will be in operation by 2050. CO2 emissions in the electricity sector (which contributes about 30% of total global emissions) in Chile will increase by 130%. Notwithstanding they

state that Chile should contribute to the global effort on the CC, but taking into account of its relative contribution to the problem. The concerns of taking measures for reducing CO2 and others to face the serious consequence of CC and global warming comes from the fact that they could impose restrictions on trade or carbon taxes, and that they can eventually damage “the competitiveness of the economy”, and by this way, the economic development. This trend of the official discourse of the elites, government officials, political and technical elite, to be aware of the issue of CC but not giving priority and subordinating it to economic growth is in contrast to the increased awareness of CC manifest in the general population as we have observed above. In actual terms the climate change concerns seem to be related to the perception of closeness (or remoteness) of risk and vulnerability1. Accordingly assessing the impact of CC must take this fact into account. In this sense the impact of CC is generally indirect and medium or long-term and only in situations involving evident climatic disasters the impact is direct. It seems that the professional and consultant elites can be more conscious of the need to address the CC than the elites directly involved in decision making at the enterprise and political levels. In the context of a progressive international society in transition, albeit slowly towards green technologies, opinions of professional elites and consultants we have analyzed just coincide. Indeed, the International Energy Agency has recently called attention to the fact that there is a 1

The UNDP Report [24] argues that surveys in developed countries, about the concerns of the population about CC rank at 13% the impact on their family while 50% think it will affect people from other countries. Most people still perceive that CC represents a moderate and distant risk.


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rapid move towards electric vehicles and solar and

capacity as suggests Van Dijk [14]. This capacity

wind energy. We are witnessing a transition towards

should be drawn in their environmental discourse.

low carbon technologies and several G20 countries are

According to the results of our research, based on

making rapid progress on the path to eliminate

secondary and primary sources and empirical data, our

subsidies to conventional fuels that will make

main hypotheses can be sustained: economic and

alternative sources a more attractive fuel.

political elites in Chile, which appears not to be an

Concerning the survey on top elite students

exception for the rest of Latin America, is aware about

(representative of groups where “future elites” are

the challenge of global warming and understands that

recruited) there are reasons to believe that the powerful

CC is a scientifically proven fact and should be taken

influence of the campaigns contrary to the shift towards

seriously.

adaptation and mitigation of CC are not strong in these

knowledge on CC have had less influence in Latin

groups of Chilean students. Even though there would

American public and elite opinion than in developed

be a slight tendency for a less favorable option towards

countries and especially in the U.S.. Therefore, the

sustainability in the future elites of the country. On the

elites seem to have an open discourse to consider

basis of the positions that this students (future

mitigation and adaptation measures to reduce the

professionals) hold in the future, based on their roles in

effects of emissions

the higher echelons of government or corporations,

situation.

taking into consideration the role taking of the future that

can

generate

interest

beyond

Campaigns

that

deny

the

scientific

in the current economic

However, our conclusion is that given its position as

individual

peripheral elites on the one hand, without having

preferences, we can conclude that there is a segment of

access to the big decisions that affect the global mode

these “future elites” with a conservative stand that

of production, and moreover, as elites who seek

could rise.

economic growth in a highly competitive globalized world, local elites are not willing to implement radical

5. Conclusions

measures towards a green economy.

The study of elites should aim to understand how

The measures and changes in a developing country,

they socially construct their opinion about changes that

peripherical in the global economy, that involves real

takes into consideration factors of CC and its

progress in reducing carbon footprints, that will

challenges and the need to generate a will to change the

strongly support non conventional renewal energies,

model of development towards a sustainable and green

will not come from decisions made by local elites and

development.

by themselves. They will gain ground to the extent that

Questions about global warming and CC, orientation

these elites are: (a) pressured by circumstances such as

towards non-conventional renewable energies, energy

the increase in catastrophic CC impacts; (b) by changes

efficiency

in the regulatory framework at the international system

and

sustainable

development

and

environmental awareness urge us to understand

(Environmental

theoretically speaking that we are not only studying

Agreements); (c) changes in local political and

collective representations in abstract, but models of

institutional structures and forces and new forms of

collective action. The key issue lies in the phrase

environmental governance, and (d) surely the pressure

“changes in decision-making”. Indeed operationally

of a public opinion much more aware of environmental

elites must be defined not only in conceptual terms as

challenges and the need to move to a sustainable

we did above, but also as groups with performative

development and to a green economy.

Summits

and

International


Acknowledgment This paper is an output of the project FONDECYT No. 1090797. The authors appreciate the support of FONDECYT (Fund for Science and Technology of Chile) for his contribution to research on which this paper is based. The authors also thank the collaboration of the following colleagues to this work: Juan Muñoz Rau, Claudio Peralta Castillo, Luis Peña Rojas and Rodolfo Ramírez Barría.

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