Thermodynamics and Adsorption Isotherms of Copper Ions Removal from Solutions Using Synthetic Zeolite X

Abstract

The sorptive removal of copper ions from aqueous solutions using zeolite X has been studied by a batch technique. The impact of solute concentration and temperature on the process of sorption were examined. Using obtained experimental values thermodynamic parameters such as: ΔG 0 , ΔH 0 and ΔS 0 were calculated. Langmuir, Freundlich, Dubinin-Radushkevich and Sips isotherms were fitted to experimental data, and their goodness-of-fit were compared. The isotherms that take into account some sort of heterogeneity were found to give a better fit to experimental data than Langmuir. An apparent free energy, calculated using Dubinin-Radushkevich isotherm, showed ion exchange type of spontaneous and endothermic sorption. The results indicated that synthetic zeolite X can be used as an efficient ion exchange material for the removal of copper ions from wastewaters.