Sci-Afric Journal of Scientific Issues, Research and Essays Vol. 2 (9), Pp. 399-403, September, 2014. (ISSN 2311-6188)
http://www.sci-afric.org Research Paper
Preparation of Activated Carbon (Chemically and Physically) From Banana pith For Heavy Metal Removal from Wastewater. *Azza El-Maghraby, Nahla Ahmed Taha and Asmaa Mahmoud Abd El- Aziz. Department of Fabrication Technology, Institute of Advanced technology and New Materials, City for Scientific Research and Technology Applications, Alexandria, Egypt. *Corresponding Author’s E-mail: [email protected]
Accepted September 1st, 2014 -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------ABSTRACT Different types of agriculture waste are used in waste water treatment such as rice straw, bagasse and peanut hulls. One of this agriculture wastes which produced with large quantities is banana pith. Different activated carbon adsorbent was prepared with various processes from banana pith either chemically or physically to improve its adsorption properties. The chemically activated carbon was prepared by using phosphoric acid and zinc chloride at 600 0C, while physically treated was prepared by heating banana pith in absence of air. The prepared activated carbon was then characterized using TGA, FTIR, SEM and particle size. The particle size analyzer show that it ranged from 7.0 nm – 35.5 nm .Finally, the adsorption capacity for heavy metal removal Ni(II) and Cu(II) was studied for different types of prepared activated carbon comparing with raw banana pith. The results of this research showed that raw and carbonized banana pith could be employed as an effective and lowcost material for the removal of heavy metals from wastewater. Key words: Banana pith, activated carbon, wastewater; heavy metals, adsorption. INTRODUCTION The presence of heavy metals in the environment can be detrimental to avariety of living species including humans. Metals can be distinguished from other toxic pollutants, since they are not biodegradable and can be accumulated in living tissues, causing various diseases and disorder . Heavy metals like Zn, Cu, Ni and As are known to have toxic effects at very low, high [2, 3] concentrations . Higher concentration of Ni causes poisoning effects like headache, dizziness, nausea, tightness of chest, dry cough, vomiting, chest pain, shortness of breath, rapid respiration, cyanosis and extreme weakness . Heavy metals are continuously released into the aquatic environment from nature processes like volcanic activity and weathering of rocks. Industrial  processes have greatly enhanced the mobilization of heavy metals . Relatively recently, biological materials (algae, bacteria, [6, 7] fungi and yeasts) , or certain waste products from industrial or agricultural operations, have also been recognized as cheap  sorbents in the removal of toxic metals. Many studies are discussed to assess the ability of low cost materials like crab shell ,     peat , sunflower stalks , pine bark , banana pith are suitable adsorbent for removal of dyes. They are cheap raw material or waste products from industries or naturally abundant biomass. Metal sorption consists of several mechanisms that quantitatively and qualitatively differ according to the metal species in solution and the origin and processing of the sorbent. Sorption process modeling is a topic of interest for the prediction of the metal partitioning between the aqueous solution and the solid surface. The aim of this paper is the study of preparation and characterization of raw, physical and chemical treated of banana pith and their adsorption capacity for heavy metal removal Ni (II) and Cu (II). MATERIALS AND METHODS Banana Pith was collected from a local market, Phosphoric acid 40% ( Riedel – Dehaen, Sigma Aldrich Labor chemikalin), Hydrochloric acid 5% (Dehaen, Sigma Aldrich Labor chemikalin ), ZnCl2 ( Sigma Aldrich, 99%), Pyrrole ( 99% extra pure, Acrros organics), FeCl3.H2O (Eastern Fine Chemicals.LTD) Nickle Sulfate (NiSO4.6H2O, Eastern Fine Chemicals .LTD).
Asmaa et al 399 Preparation of Banana pith The collected banana pith was extensively washed under tap water to remove any particulate, sprayed with distilled water. The banana pith was cut into small pieces, dried using liquid nitrogen before cutting to remove moisture, crushed and sieved through a 1mm size before using in adsorption experiments without any further treatment. Physical Preparation of activated carbon This treatment was done by using Pyrolysis process (Carbonization) which has been done in a closed stainless steel tube (with length of 12.5 cm and inner diameter 2.5 cm) which full with prepared Banana Pith to avoid presence of air, the tube had a small hole in the top for venting gases produced during carbonization process, Heat it at 600°C in Muffle Furnace for 1 h then left to be cold for room temperature and then storage to be used in adsorption experiments. Chemically Preparation for activated carbon Treatment by using Phosphoric acid: The dried cute Banana pith material was soaked in a boiling solution of 40 % H3PO4 for one hour and kept at room temperature for 24 hours. After that, the pith was separated, air dried and carbonized in muffle furnace at 400°C. Then the material was washed with plenty of water to remove residual acid, dried and stored in a tight lid container for adsorption studies. Treatment by using Zinc chloride: The dried cute banana pith was impregnated in aqueous solutions containing 0.05 M zinc chloride. Impregnation was continued for 72 h with occasional stirring. The mixture was then dried and then carbonized at 600 ◦C in a limited air. The carbonized product was then lixiviated with5% HCl and then was washed with distilled water till free from chloride ions. The carbon was dried and stored. Preparation of poly pyrrole polymer Composite In order to achieve uniform coating, the banana pith was sieved into particle size of 1 mm before coating. The polymerization was done on pith by soaking in the monomer solutions (0.20 M). The oxidant (0.50 M FeCl3), was slowly added with the mixture at room temperature for 2 hours. The polymer coated pith was filtered, washed with distilled water, dried at 60°C (in an oven) and sieved before use. RESULT AND DISCUSSION Characterization of raw and treated materials was done using FTIR, TGA, SEM and particle size analyzer to clarify the difference between the raw and treated materials and how these changes may enhance the adsorption process. Structure characteristic of the prepared samples were investigated through FT-IR spectrophotometer (FTIR-8400S, Shimadzu) with a resolution of 2 Cm-1and thermal decomposition of the samples was studied using thermogravimetric analysis (TGA) (TGA-50 0 0 0 -1 Shimadzu). The measurement was carried out from 50 C to 800 C with heating rate of 10 C min with nitrogen flow rate of 20 ml -1 min . Scanning electron microscope (JOEL, SEM) micrographs, Equipped with EDX Falcon system which operated at 10 keV. Particle size analysis based on Beckman Coulter N5 Submicron Particle Size Analyzer. Physical characterization IR – Spectrophotometer study: Figure (1) shows the FTIR Spectra of Raw material of banana pith. The analysis of these spectra -1 revealed the broad band in the range 3430-3465cm correspond to O-H stretching vibration and the overlapping of the O-H stretching bands of hydrogen bonded water molecules ( H-O-H-H) adsorbed on the raw material surface. The peak located at 1630 cm-1 was characteristics of the carbonyl group stretching from carboxylic acids and ketones, this band intensity decreased gradually for different types of Activated carbons till disappeared in case of composite activated carbon that is showed in figure (2) . The band that observed at 1051 cm-1 was due to the C-O group in carboxylic and alcoholic groups, but the band at 1440 cm-1H-CH bending. The analysis of the FTIR spectrum showed the presence of ionizable groups (carboxyl and hydroxyl) able to interact with protons, metal or positive dye ions these functional groups may be the major adsorption sites for metal removal.
Figure 1: FTIR curve of raw banana pith.
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Figure 2: FTIR curve of physical and chemical treated banana pith and composite activated carbon. Surface Morphology Study: Figure (3) shows the surface structure of raw and treated banana pith tissue using SEM with magnification factor of 1000. The figures illustrate that surface has roughness for all samples and this roughness increase for treated ones than raw material especially for physically treated samples followed by treated with ZnCl2 and H3PO4. These changes may be enhanced by the removal process, as the adsorption of metal ions from waste water depends on the surface properties of sorbent material. This also observed across the following removal data of Ni(II), Cu(II) by making comparison between the different samples prepared. The surface of a support (different activated carbons) in the preliminary stage of adsorption can be considered as a capacitor plate where the ions stick  It can be observed that the amount of Ni(II), Cu(II) taken up by activated carbon increased with physical than chemical treatment.
(a): SEM of Raw material.
(b): SEM of pyrolysis activatedcarbon.
(C): SEM of ZnCl2 activated carbon.
(d): SEM of H3PO4 activated carbon.
(E): SEM of poly pyrolle Composite Figure 3: Surface structure of raw and treated banana pith tissue using SEM with magnification factor of 1000
Asmaa et al 401 Thermal stability study: The Raw material, physical and chemical activated carbon samples were examined by thermogravimetric analysis as shown in Fig. (4) .TG Analysis shows that the ZnCl2 and H3PO4 activated carbon are more thermally stable than the raw and physical treated one. As the total mass loss for ZnCl2, H3PO4 activated carbon , raw material and pyrolysis activated carbon are 50 %, 58 % ,62.4% and 32.1% respectively which evident the previous conclusion.
Figure 4: .TG Analysis Curve for Raw material, physical and chemical activated carbons. Study of Particle Size: Particle size distribution of raw and treated banana pith was studied. Average particle sizes shows in (Table 1). The table can conclude that the smallest particle size was for composite sorbent followed by the raw material and the largest for H3PO4 treatment. The above results may be indicator for sorbent removal efficiency as smallest particle size give large surface area to high removal efficiency. Table 1: Particle size distribution of raw and treated banana pith Material
Particle Size ( nm)
Adsorption study Raw and different prepared sorbents from banana pith was tested for removal of Cu(II) , Ni(II) from waste water, to evaluate using them as sorbent material. Study removal percentages of Cu(II) from waste water: Effect of sorbents dosage on percentage removal of Cu(II) was deliberated by varying adsorbents dosage in the range of 0.05g-0.3g. It was observed that percentage removal of Cu(II)decreased by increasing of adsorbent prescribed amount (Fig.5). All prepared materials enable to sorbs ions at low dosage weight especially at 0.05 g, with maximum removal percent for all prepared materials. The removal percent reach 100% for both raw material banana pith and pyrolysis activated carbon, this phenomenon is due to the highest surface area that is appeared in the SEM  characterization of raw and physical treated ones rather than other prepared materials that also increase the rate of adsorption .
120 100 80
Weight(g) Figure 5: Removal percent of Cu(II) from waste water as a function of material dosage.
Asmaa et al 402 Study removal percentages of Ni(II) from waste water: The effect of quantity on the adsorbent was studied by varying the amount of adsorbed from 0.05 to 0.3 g. The adsorbent was added to 20 ml of Ni(II) solution of 50 ppm concentration and equilibrated for 2 hours. The results in figure 6 indicated that adsorption percent with increase the adsorbed dosage. Removal percentage increased with decreasing the adsorbent dosage. The removal percent reach about 70% for both raw material banana pith and composite samples. The lowest weight indicates the largest removal percent this due to particles accumulation incase of higher weight .This increasing of adsorption percent due to availability of more surface area of the adsorbent. The high surface area that is appeared in the SEM characterization of raw and physical treated ones rather than other prepared materials, that also increase the rate of adsorption and also refers to the smallest particle size of these two sorbent according to particle size analyzer data as mentioned before.
Figure 6: Removal percent of Ni(II) from waste water(300 rpm , 50 ppm , 2hours) CONCLUSION The present study showed full characterization of banana pith and four types of chemical and physical treated activated carbons from raw banana pith. SEM figures showed the difference in topographic surface for different materials. Infrared analysis comparison between the raw and treated samples cleared the important function groups which affecting sorption process and thermo gravimetric analysis was done for all samples concluding that ZnCl2 and H3PO4 treated activated carbon are more thermally stable than the raw and physical treated one by studying the comparison of all the prepared samples on Ni ( II), Cu (II) removal percentages. The highest removal was for raw and pyrolysis materials in case of Cu (II), while for raw and composite activated carbon in case of Ni (II) removal. References [1.] Isabel Villaescusa, NuriaFiol, 2004, Removal of copper and Nickle ions from aqueous solution by grape stalks wastes, Water research 38, 992-1002. [2.] Davey EW, Morgan MJ, Erickson SJ, 1973, A biological measurement of copper complexation capacity in seawater. Limnology and Oceanography, 18:993-997. [3.] Nies DH, 1980, Resistance to cadmium, cobalt, zinc and nickle in microbes. Plasmid-Determined Metal Resistance. Ajournal of Mobile Genes and Genomes, 27:17-28. [4.] RevathiM, 2005, Removal of Nickle ions from industrial plating effluents using activated alumina as adsorbent. Journal of Environmental Engineering, 47:1. [5.] ManjeetBansal, Diwan Singh, 2009, Use of agricultural waste for the removal of nickle ions from aqueous solutions : Equilibrium and akainetics Studies. World AcademyofScience, Engineering and Technology 27. [6.] Mattuschka B, Straube G, 1993, Biosorption of metals by a waste biomass. J Chem Tech Biotechnol58:57-63. [7.] Pagnanelli F, Petrangli PM, Toro L, Trifoni M, Veglio F, 2000, Biosorption of metal ions on Arthrobactersp; biomass characterisation and biosorption modeling. Environ SciTechnol, 34:2773-8. [8.] An HK, Park BY, Kim DS, 2001, Crab shell for the removal of heavy metals from aqueous solutions. Water Res, 35:35516. [9.] McKay G, Portr JF, 1997, Equilibrium parameters for the sorption of copper, cadmium and zinc ions onto peat. J ChemTechnolBiotechnol, 69: 309-20. [10.] Sun G, Shi W, 1998, Sunflower stalks as adsorbents for the removal of metal ions from wastewater. Ind ENG., 37:1324-8.
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