Amidoxime functionalized chitosan/β-cyclodextrin composite for removal of Cu2+, Pb2+, and Zn2+

To address the challenge of removing heavy metal ions from industrial effluents, chitosan-based adsorbent materials have been extensively reported, particularly in terms of composite materials and the introduction of groups. In this paper, β- cyclodextrin ( β -CD) and amidoxime (AO) were simultaneously chemically cross-linked with chitosan (CTS) for the first time, resulting in amidoxime functionalized chitosan/ β- cyclodextrin composite (CTS-g-AO- β -CD) which was primarily applied to remove toxic metal ions. The adsorption capacities of CTS-g-AO- β -CD were 35.66, 31.28, 16.46 mg/g for Cu 2+ , Pb 2+ and Zn 2+ . The adsorption of Cu 2+ and Pb 2+ followed the pseudo-second-order kinetic and the Langmuir isotherm model, whereas the adsorption of Zn 2+ adhered to the pseudo-second-order kinetic and Freundlich isotherm model more closely. After five regeneration cycles, CTS-g-AO- β -CD still retained a certain adsorption performance, demonstrating its potential for application as a novel adsorbent.