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Title
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Removal of cadmium and nickel from aqueous solution by natural and modified bentonite
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Type
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Presentation
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Keywords
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Natural bentonite, Modified bentonite, Na+ cations
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Abstract
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Recently, the usage of natural mineral adsorbents for wastewater treatment is increasing due to their abundance and low price. One type of clay minerals is bentonite. High specific surface area and cation exchange capacity makes bentonite a useful clay mineral for the decontamination of heavy metal ions. In this study natural and modified Iranian bentonite was tested for removal of cadmium (Cd2+) and nickel (Ni2+) ions from aqueous solution. Modified form of clay was prepared by saturating with Na+. Batch adsorption experiments were performed using 50 mL capped polyethylene tubes with L/S: 10/1 and Cd2+ and Ni2+ concentration from 25 to 600 mg L-1. The results demonstrate that treatment with Na+ have positive effect on increase the sorption capacity of natural adsorbent with increasing the pH. The pH of zero point charge (zpc) was determined for modified clay. Result shows pHzpc value for modified clay less than the pHzpc of natural clay. The two most common isotherm models, Langmuir and Freundlich, were used to describe the adsorption equilibrium data. The Langmuir adsorption capacities of Cd2+ and Ni2+ were 37.0 and 45.9 mg g−1 respectively for Na-bentonite.
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Researchers
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Seyedeh Bahareh Azimi (Second Researcher), Hajar Merrikhpour (First Researcher)
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