Competitive adsorption of toxic metals on bentonite and use of chitosan as flocculent coagulant to speed up the settling of generated clay suspensions

Evaluation of modified Algerian clay as mineral adsorbent was done for its adsorbing capacity on copper (Cu) and Zinc (Zn) cations. The results obtained show a rapid kinetic adsorption for both metals (less than 2 h) following the pseudo-second order model with high elimination rates of 67.2 and 61.8% for Cu and Zn respectively. The adsorption isotherms analyzed with Langmuir model revealed a correlation with the experimental values. While the use of obtained chitosan at room temperature, as flocculent coagulant, accelerates the decantation of the colloidal particles in suspension generated after adsorption process. •A mineral adsorbent was synthetized from modified Algerian clay.•We studied the adsorption of heavy metal ions on the adsorbent.•Fitting of experimental isotherm data by non-linear Langmuir and Freundlich models were studied.•The adsorbent shows high adsorption capacity and good selectivity for Cu and Zn.