Response Surface Modeling of the High Concentration Pb2+ Adsorption onto Cross-linked Xanthated Chitosan

Abstract

Cross-linked xanthated chitosan was prepared as an adsorbent for removal of Pb²⁺ from aqueous solution. Adsorption of Pb²⁺ onto cross-linked xanthated chitosan was optimized using response surface methodology. A three level Box-Behnken design based on response surface methodology was employed to analyze the combined effect of pH, adsorbent dosage and contact time on adsorption capacity. The optimum values of the selected variables were determined to be: pH 5.66, adsorbent dosage 0.058 g and contact time 95 min for Pb²⁺ removal. In the optimal conditions, the corresponding Pb²⁺ adsorption capacity on cross-linked xanthated chitosan was found to be 446.8 mg/g.