New heterocycle modified chitosan adsorbent for metal ions (II) removal from aqueous systems

A new hydrogel based on a modified chitosan CS-B was synthesized and evaluated for its metal ion removal from aqueous systems. The CS-B hydrogel was prepared through modification of chitosan with 4((1, 3-dioxoisoindolin-2-ylimino) methyl) benzaldehyde as a heterocyclic component. The new hydrogel was analyzed by diverse techniques such as FTIR, XRD, TGA, SEM, and swelling tests. The adsorption capacity of CS-B for metal ions Co2+, Hg2+, Cu2+, Zn2+, and Pb2+ from aqueous systems at different pH values showed various levels of efficiency. The metal ion uptake data over a range of pH values for Co2+ and Hg2+ showed the highest adsorption capacity while Cu2+, Zn2+, and Pb2+ showed moderate adsorption capacity. Selective metal ion efficiency was highest for Co2+ and lowest for Hg2+ in their binary mixture. (C) 2014 Elsevier B.V. All rights reserved.