Glutaraldehyde cross-linked epoxyaminated chitosan as an adsorbent for the removal and recovery of copper(II) from aqueous media

A novel glutaraldehyde cross-linked epoxyaminated chitosan (GA-C-ENCS) prepared through chemical modification was used as an adsorbent for the removal and recovery of Cu(II) from aqueous media. The adsorbent was characterized by FTIR, SEM-EDS, ESR, TG/DTG, BET-surface area and potentiometric titration. The Cu(II) adsorption process, which was pH dependent showed maximum removal at pH 6.0. Adsorption equilibrium was achieved within 3 h. The adsorption of Cu(B) followed a reversible-first-order kinetics. The equilibrium data were evaluated using the Langmuir, Freundlich and Dubinin-Raclushkevich isotherm models. The best interpretation for the equilibrium data was given by the Dubinin-Radushkevich isotherm. The adsorption capacity of the adsorbent increased from 3.11 to 3.71 mmol g(-1) when the temperature was increased from 20 to 50 degrees C. The complete removal of 20.7 mg L-1 Cu(II) from electroplating industry wastewater was achieved by 0.4 g L-1 GA-C-ENCS. Regeneration experiments were tried for four cycles and the results indicate a capacity loss of <7.0%. (C) 2009 Elsevier B.V. All rights reserved.