Gold sorption on chitosan derivatives

Four derivatives of chitosan have been prepared by cross-linking and by grafting of sulfur compounds. Sorption isotherms were performed at different pHs in order to optimize the pH conditions at fixed chloride concentration. Sorption isotherms were correlated with gold speciation in solution. Sulfur grafting decreases the influence of the pH on sorption isotherms. Introducing sulfur chelating moieties gives a dual structure to the polymer: chelating and ion exchange capability. Sorption kinetics was influenced by the sorbent dosage and the type of sorbent used. (C) 2003 Elsevier B.V. All rights reserved.