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Feb 20, 2015 - Quaternaqy geology of some selected drainage basins in Upper Egypt (Qena-Edfu area). Ph. D. Thesis, Faculty of Science, Cairo University, ...

Advances in Natural and Applied Sciences, 9(5) May 2015, Pages: 16-26 AENSI Journals

Advances in Natural and Applied Sciences

ISSN:1995-0772 EISSN: 1998-1090 Journal home page: www.aensiweb.com/ANAS

Evaluation of groundwater quality and its suitability for drinking and agricultural uses in SW Qena Governorate, Egypt. Salman A. Salman and Ahmed A. Elnazer Geological Sciences Department, National Research Centre, Dokki, Cairo, Egypt. ARTICLE INFO Article history: Received 4 December 2014 Received in revised form 10 January 2015 Accepted 8 February 2015 Available online 20 February 2015

ABSTRACT Groundwater is an important source of freshwater for uses in many regions over the world, especially arid regions as Egypt. To assess the groundwater quality for drinking and agricultural at SW Qena Governorate, 38 groundwater samples were collected and subjected to a comprehensive physicochemical analysis. This groundwater is alkaline, fresh and hard water. According to WHO specification, more than half of the samples are suitable for drinking purpose according to their chemical constituents. Also, this water is suitable for irrigation purpose according to the irrigation quality parameters, except some samples with high salinity and magnesium hazard.

Keywords: Water quality, Drinking water, Irrigation Water, Qena Governorate © 2015 AENSI Publisher All rights reserved. To Cite This Article: Salman, S.A. and Elnazer, A.A., Evaluation of groundwater quality and its suitability for drinking and agricultural uses in SW Qena Governorate, Egypt. Adv. in Nat. Appl. Sci., 9(5): 16-26, 2015

INTRODUCTION With the growing of populations and human activities in Egypt, the demand for groundwater has increased. Groundwater is the only reliable water resource for human consumption, as well as for agriculture and industrial uses in the desert area in SW of Qena Governorate. So pumping from the Plio-Pleistocene aquifer is widely practiced in this area. It is now generally recognized that the quality of groundwater is of the same importance as its quantity. Water quality and human health are inextricable linked (Salem et al., 2000). Groundwater quality is based upon the physical and chemical soluble parameters due to weathering from source rocks and anthropogenic activities. Suitability of water for various uses depends on the type and concentration of dissolved minerals and groundwater has more mineral composition than surface water (Mirabbasi et al., 2008; Salman, 2013). The quality of groundwater depends on several factors such as soil-water interaction, dissolution of mineral species, duration of solid-water interaction and the anthropogenic source (Hem 1989; Appelo and Postma, 2005). Anthropogenic activities like urban development and agricultural activities (inputs of fertilizer and pesticides) directly or indirectly affect the groundwater quality (Kim et al., 2004; Jalali, 2005; Srinivasamoorthy et al., 2009; Zhang et al., 2011). The objective of the present study is to assess the chemical groundwater composition and its suitability for drinking and agricultural purpose in SW Qena Governorate. The study area is lying to the southwest of Qena Governorate between latitudes 25° 56′ 52′′N to 26° 12′ 21′′N and longitudes 32° 1′ 40′′E to 32° 42′ 19′′E (Fig. 1). This area has desert climate conditions with temperature varies between 27 - 47° and 7 – 28° in summer and winter respectively. Rainfall is rarely occurs and the average annual rainfall does not exceed 4 mm/year (Abdallatief et al. 2012). Geology of Qena was studied by many authors such as Said (1962, 1981 and 1993), Askalany (1988), Issawi and McCauley (1992), El- Balasy (1994), Abadi (1995) and Mansour et al. (2001). Qena area (Fig. 2) covered by sediments and sedimentary rocks ranging in age from Lower Eocene to Recent. The Lower Eocene is represented by Thebes Formation. This formation consists of hard limestone with many flint bands and marl intercalations. The Pliocene consists of interbeded red brown clay, Paleonile (Madamoud Formation), which acts as an aquiclude for the overlying Quaternary aquifers. The Pleistocene and Recent subdivided into different formations, these are fluviatile and alluvial deposits covering most of the study area in the form of gravel, coarse sand, and loamy materials.

Corresponding Author: Salman A. Salman, Geological Sciences Department, National Research Centre, Dokki, Cairo, Egypt Box.12311. E-mail: [email protected]

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Salman and Elnazer, 2015 Advances in Natural and Applied Sciences, 9(5) May 2015, Pages: 16-26

Fig. 1: Location map of the study area showing the sampling sites.

Fig. 2: Geologic map of Qena governorate (modified from Conoco, 1987). According to Abu El Ella (1993), Shedeid et al. (2001) and Aggour et al. (2005), the water bearing sediments in the study area are composed of the Plio-Pleistocene sediments which consist of clayey sand layers. The saturated thickness of it ranges from 40 m close to the limestone boundary and 80 m adjacent to the floodplain. The groundwater is generally under phreatic conditions. This aquifer is characterized by low productivity and its hydraulic interconnection with the floodplain Quaternary aquifer. The Plio-Pleistocene

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Salman and Elnazer, 2015 Advances in Natural and Applied Sciences, 9(5) May 2015, Pages: 16-26

aquifer is recharged vertically from excess irrigation water in the new reclaimed lands and is presumably from deeper aquifer systems (RIGW 1992). It is discharged mainly through horizontal flow to the Quaternary aquifer or vertically by pumping. MATERIALS AND METHODS Groundwater samples were collected from 38 boreholes in Jan 2014 at SW Qena Governorate (Fig. 1). Water from the wells was pumped out for over 20 minutes, before abstracting the samples in well cleaned one litre polythene bottles. The temperature, pH, TDS and electrical conductivity (EC) were determined at the site with the help of digital HANNA pH meter (HI 991300) which was calibrated prior to taking of readings. The samples were filtered and analyzed for chemical constituents by using standard procedures (APHA 1995). Sodium and potassium were determined by flame photometer. Total hardness (TH) as CaCO3, calcium (Ca2+), magnesium (Mg2+), carbonate (CO32-), bicarbonate (HCO3‾) and chloride (Cl‾) were analyzed by volumetric methods. Sulfates (SO42-) were estimated by using the calorimetric technique. Iron and Mn were determined by using Atomic Absorption Spectrophotometer. The analytical precision for the measurements of ions was determined by the ionic balances, which was below 5%. RESULTS AND DISCUSSION Hydrochemical Characteristics and Classification: Descriptive statistics of chemical constituents of collected groundwater samples are presented in Table (1). The pH value ranged from 6.96 to 8.79, this indicating study area water falls in alkaline nature. This high pH, possibly due to the presence of considerable amount of sodium, calcium, magnesium, carbonate and bicarbonate ions which progressively increase the pH and alkalinity (Rao et al., 1982; Njitchoua et al., 1997). The electrical conductivity ranges from 430 to 3270 µS/cm. The large variation in EC is mainly attributed to geochemical process like ion exchange, reverse exchange, evaporation, silicate weathering, rock water interaction, sulphate reduction and oxidation processes (Ramesh and Elango, 2012) and anthropogenic activities like application of agrochemicals. TDS in the study area vary in the range of 285 - 2188 mg/l with an average value of 1074.7 mg/l. The high TDS values may be attributed to leaching of salts from Plio-Pleistocene sediments containing salts of sulfates and chlorides (Elewa 2004). According to Chebotarev (1955) classification (Table 2) all the samples are considered fresh water, ranging from good potable to passably fresh. In addition, the total hardness value varies from 60.4 to 600 mg/l (Table 1) which may be due to presence of calcium and magnesium in the country rocks. The results indicted that 6 samples are medium hard water, 20 samples are hard water and 12 samples are very hard water (Table 3) according to Boyd (2000) classification of water hardness. Table 1: Descriptive statistics of the physico-chemical parameters of groundwater of Qena Governorate WHO (2004) specification. TDS EC TH Ca Mg Na K HCO3 SO4 Cl Fe Mn parameter pH mg/l µS/cm mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l Mean 8.08 1074.7 1611.6 274.4 77.6 47.8 125.3 9.7 213.9 162.6 244.6 0.189 0.221 Median 8.16 984.5 1475.0 249.3 76.4 44.8 115.3 9.2 205.7 161.4 216.0 0.125 0.000 SD 0.38 463.7 696.1 129.6 37.0 24.6 59.0 2.5 84.9 93.2 145.6 0.364 0.401 Range 1.83 1903 2840.0 539.6 155.4 107.4 256.8 14.3 405.2 399.4 586.0 2.190 1.650 Min. 6.96 285 430.0 60.4 18.0 9.9 28.5 2.4 54.9 23.8 30.2 0.010 0.000 Max. 8.79 2188 3270.0 600.0 173.4 117.3 285.3 16.7 460.1 423.2 616.2 2.200 1.650 Q1 7.96 692.8 1032.5 203.8 49.1 34.1 81.9 8.4 157.4 92.9 133.9 0.020 0.000 Q2 8.37 1380.3 2075.0 331.2 104.1 56.8 157.9 10.6 252.7 210.0 329.9 0.200 0.288 WHO 6.5-9.2 1000 1500 500 200 150 200 200 240 250 250 0.3 0.4 2004 SD: Standard Deviation Q1: 1st Quartile Q3: 3rd Quartile Table 2: Classification of water according to TDS. Water Type Good potable Fresh water Fresh Fairly fresh water

Brackish water

Salt water

Passably fresh Slightly brackish Brackish Definitely brackish Slightly salt salt Very salt Extremely salt Sea water

TDS (mg/l) 10000 35000

Samples 16, 24 and 31 1, 5, 6, 7, 9, 12, 26, 28, 34 and 36 2, 3, 4, 8, 10, 11, 15, 17, 18, 20, 21, 22, 23, 25, 27, 29, 30, 31, 33 and 37 13, 14, 19, 32, 35 and 38 ---------

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Table 3: Water classification according to TH. TH (mg/l) Type

Samples

< 50

Soft

-

50 - 150

Medium hard

6, 7, 9, 16, 24 and 28

150 - 300

Hard

1, 3, 4, 5, 10, 11, 12, 15, 17, 18, 23, 26, 29, 30, 31, 32, 33, 34, 36 and 37

>300

Very hard

2, 8, 13, 14, 19, 20, 21, 22, 25, 27, 35 and 38

Water naturally contains number of different dissolved inorganic constituents (Table 1). The major cations are Ca2+, Mg2+, Na+ and K+ flocculated around 77.6, 47.8, 125.3, 9.7 mg/l, respectively (Table 1). The anions are Cl‾, SO42- and HCO3‾ flocculated around 244.6, 162.6 and 213.9 mg/l, respectively (Table 1). Carbonate anion was absent in all the analyzed samples. The geochemical composition of groundwater indicates a direct relation between the lithology and relative abundance of ions. Where, the dominance of Na+ and Cl‾ ions in the groundwater of the study area is related to leaching processes of highly soluble minerals salts such as halite which associated with Pliocene sediments in the study area (Abdalla et al., 2009; Hamdan, 2013). Iron and manganese display great variations both laterally and vertically in groundwater throughout the Nile valley. The mean concentration of Fe and Mn in the groundwater is 0.14 and 0.22 mg/l, respectively (Table 1). The depleted content of Fe and Mn in this groundwater is attributed to the poverty of ferromagnesian minerals in the water bearing sediments in the desert areas of Nile valley (Omer 2003; Gomaa 2006). The groundwater types in the study area were determined based on their chemical composition using the piper trilinear diagram (Piper, 1944). The plot shows that most of the groundwater samples analyzed fall in the field of the earth alkaline water with increase portion of alkalis with prevailing sulphate and chloride (Fig. 3). Also, some samples are of alkaline water with prevailing sulphate and chloride and two samples are in the field of earth alkaline water with increase portion of alkalis with prevailing bicarbonate. Evaluation of Water Suitability for Drinking: The quality of drinking water is an issue of primary interest for the consumers. All the studied quality parameters (pH, TDS, EC, TH, Ca2+, Mg2+, Na+, K+, Cl‾, SO42- and HCO3‾) have been compared with the WHO (2004) specification for drinking water (Table 1). Accordingly, all the water samples are with pH values of the desirable ranges for drinking water. About 45% of the samples (18 samples) are crossing the maximum permissible limit of 1000 mg/l and 1,500 µS/cm for TDS and EC, respectively. However, only three samples (samples 8, 13 and 19) are out of desirable limit for TH (500 mg/l) in drinking water. But, most the groundwater samples fall in the hard (20 samples) to very hard (12 samples) category (Table 3). There is some suggestive evidence that long term consumption of extremely hard water might lead to an increased incidence of urolithiasis, anencephaly, prenatal mortality, some types of cancer and cardiovascular disorders (Durvey et al., 1991; Agrawal and Jagetai, 1997).

Fig. 3: Piper trilinear diagram indicating the groundwater type.

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Ca2+, Mg2+and K+ concentrations are within the acceptable limit of drinking water (Table 1). However, some samples have inadequate levels of Na+, Cl‾, SO42- and HCO3‾ ions in comparison with WHO (2004) specification for drinking water. Sodium overdose acute effects may include nausea, vomiting, convulsions, muscular twitching and rigidity, and cerebral and pulmonary oedema (Elton et al., 1963; DNHW, 1992). In addition, high concentrations of Cl‾ in drinking water cause a salty taste and have a laxative effect (Bhardwaj and Singh, 2011) in people not accustomed to it. Also, reported diarrhea associated with the ingestion of water containing high levels of sulfate was recorded (USEPA, 1998). Iron is one of the most abundant metals on earth and is an essential element for the normal physiology of living organisms. Both its deficiency and overload can be harmful both for animals and plants (Anonymous, 2008). In drinking water the desirable concentration set by WHO (2004) is 0.3 mg/l for iron. Nearly all the studied samples have acceptable levels of Fe except samples 7, 34 and 38. Manganese is an essential trace nutrient for all forms of life (Emsley, 2003) as it binds to and/or regulates many enzymes in the body (Crossgrove and Zheng, 2004). Only 4 samples (1, 7, 21, 28 and 38) cross the desirable limit of 0.4 mg/l for drinking water. Evaluation of Water Quality for Irrigation: Water Salinity: Water salinity can be assessed based on TDS or EC. High salt content in irrigation water causes osmotic pressure in soil solution (Thorne and Peterson, 1954). Also it affects soil structure, permeability, aeration, texture and makes soil hard (Trivedy and Geol, 1984). According to the USEPA (1976) classification of water TDS for arid and semi-arid regions (Table 4), only 2 samples are of class I, 1 sample of class IV, 18 samples of class II and the rest of samples are of class III. Table (5) shows the classification of groundwater samples for irrigation water use based upon electric conductivity (Richards, 1954). Accordingly, 84% of the samples are permissible for irrigation with EC

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