Removal of cadmium(II), lead(II), and chromium(VI) ions from aqueous solution using clay |
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Authors: | Tabrez A Khan Ved Vati Singh |
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Institution: | 1. Department of Chemistry , Jamia Millia Islamia , New Delhi 110 025, India takhan501@yahoo.com;3. Department of Chemistry , Jamia Millia Islamia , New Delhi 110 025, India |
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Abstract: | Removal of cadmium(II), lead(II), and chromium(VI) from aqueous solution using clay, a naturally occurring low-cost adsorbent, under various conditions, such as contact time, initial concentration, temperature, and pH has been investigated. The sorption of these metals follows both Langmuir and Freundlich adsorption isotherms. The magnitude of Langmuir and Freundlich constants at 30°C for cadmium, lead, and chromium indicate good adsorption capacity. The kinetic rate constants (K ad) indicate that the adsorption follows first order. The thermodynamic parameters: free energy change (ΔG o), enthalpy change (ΔH o), and entropy change (ΔS o) show that adsorption is an endothermic process and that adsorption is favored at high temperature. The results reveal that clay is a good adsorbent for the removal of these metals from wastewater. |
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Keywords: | adsorption cadmium(II) lead(II) chromium(VI) clay Langmuir and Freundlich isotherms thermodynamic parameters |
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