Equilibrium, Langmuir Isotherms and Thermodynamic Studies for Adsorption of Cu(II) on Natural Clay

Abstract

We have studied the pH and the temperature effects on copper ions adsorption on natural and treated clays from ENOF Chemical Ltd., Research Company, Algeria. Treated clay was studied to improve the adsorption capacity. X-Ray diffraction identified montmorillonite and kaolinite as major clay minerals. The langmuir adsorption model was used for the mathematical description of the adsorption equilibrium and the equilibrium data adhered very well to this model. The treated and natural clay had the monolayer adsorption capacity equal to 15.40 and 12.22 mg.g−1 respectively at pH value of 6.5 and 20 °C and the adsorption isotherms could be fitted with Langmuir isotherms, and the coefficients indicated favorable adsorption of Cu(II) on the clays. Determination of the thermodynamic parameters, H, S and G showed that the adsorption process was spontaneous and exothermic accompanied by decrease in entropy and Gibbs energy. Results of this study will be useful for future scale up for using this material as a low-cost adsorbent for the removal of Cu(II) from wastewater.