Application of Adsorption Thermodynamics and Column Studies for Pb2+, Cd2+ and Mn2+ Ions Removal in Multicomponents Model Solution Using Low-Cost Bentonite Clay Adsorbent

Abstract

The presence of heavy metal contaminants in wastewater effluents has become a great threat to living creatures and the environment. In this study, the application of thermodynamics and column studies for Pb2+, Cd2+ and Mn2+ metal ions removal in multicomponent aqueous solution using low-cost bentonite clay was investigated. Evaluation of enthalpy (∆Ho), entropy (∆So) and Gibbs free energy (∆Go) revealed that heavy metals adsorption was endothermic and spontaneous as temperature increased from 30 to 65 oC. The column performance was determined at 0.05m adsorbent bed depth, 0.023 and 0.04 mL/s flow rates. The influent concentration was 10 and 50 ppm while the breakthrough time was between 0.83 and 8 hr. The maximum uptake of metal ions was 2.2 mg/g for Pb(II), Mn(II) was 0.4 mg/g and 1.7 mg/g for Cd(II). The result showed the potential of bentonite clay as a candidate for toxic metal ions adsorption in wastewater.