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 Co(2+), Hg(2+), Cu(2+), Zn(2+), and Pb(2+) from aqueous systems at different pH values showed various levels of efficiency. The metal ion uptake data over a range of pH values for Co(2+) and Hg(2+) showed the highest adsorption capacity while Cu(2+), Zn(2+), and Pb(2+) showed moderate adsorption capacity. Selective metal ion efficiency was highest for Co(2+) and lowest for Hg(2+) in their binary mixture.