Competitive adsorption of Cu (II) and Zn (II) on impregnate raw Algerian bentonite and efficiency of extraction

Abstract

Impregnated homoionic raw Algerian bentonite (HB) with high basal spacing was prepared to remove a copper (Cu2+) and zinc (Zn2+) from 0.33M (Na+, H+)SO42− sulphate medium in aqueous solutions. The impregnated solid was characterized by X-ray diffraction (XRD), Fourier- Transform Infrared (FTIR) and Ultra-violet (UV). The effect of contact time, initial pH of a solution, heavy metal concentration and ligand concentration on the adsorption efficiency were investigated. Pseudo-first/s orders isotherms are applied to determine the efficiency of impregnate solid. The experimental data fitted well with the pseudo-second order model for Cu2+ and Zn2+ adsorption. Maximum capacities for Cu2+ and Zn2+ were 440mmol/kg and 32mmol/kg respectively. However, the adsorption is selective to copper in binary system. Moreover, impregnated solid was also regenerated and reused for subsequent recovery.