Adsorption of cadmium and lead in wastewater by four kinds of biomass xanthates

Abstract

This study determined the adsorption of Cd²⁺ and Pb²⁺ (100 mg·L^-1 of each) in simulated wastewater by biomass xanthates made from starch, chitosan, wheat stalk and corn stalk. The results showed that the adsorption efficiency of Pb²⁺ and Cd²⁺ ions followed the order: corn stalk xanthate > wheat stalk xanthate ≥ chitosan xanthate > starch xanthate. The results of kinetic modeling showed that the adsorption process was characterized by physical-chemical adsorption, and that a second-order kinetics equation described the adsorption process well. The optimum conditions for the adsorption of Cd²⁺ and Pb²⁺ by corn stalk xanthate were: adsorption time 2 hours, temperature 20-25 °C, and pH 6-8. The results serve as a reference for treating wastewater containing Cd²⁺ and Pb2⁺.