COMPARATIVE STUDY OF METAL IONS ADSORPTION IN AQUEOUS MEDIA BY CROSS-LINKED CHITOSAN MEMBRANES

Abstract

In this work, multi-elements solutions with metallic ions of different initial concentrations were prepared to compare the removal capacities of chitosan membranes cross-linked with epichlorohydrin (CS−ECH) and glutaraldehyde (CS−GLA). The pseudo-second kinetic equation presented better fit in CS–ECH, while the pseudo-first kinetic model obtained a higher correlation coefficient in CS–GLA sample, except for Al ³⁺ ion. The Freundlich isotherm presented the best fit in both types of membrane. CS–ECH membrane obtained sorption capacity for Cu²⁺, Pb²⁺, Al³⁺, Zn²⁺ e Cd²⁺, respectively, of 53.87, 13.66, 4.41, 2.31 and 1.66 mg g^-1. The values obtained by CS–GLA membrane for the same sequence of ions were of 20.25, 3.42, 2.54, 9.23 e 8.77 mg g-¹