Fe3O4-β-cyclodextrin-Chitosan Bionanocomposite for Arsenic Removal from Aqueous Solution

The aim of this present work is to investigate the adsorption capacity, kinetics and mechanism of arsenite ion removal onto beta-Cyclodextrin-Chitosan-Fe3O4 nanocomposite (beta-CD-CS-Fe3O4 nanocomposite) from aqueous solutions. Iron oxide nanoparticles (Fe3O4) were synthesized using the co-precipitation method and the nanocomposite was successfully prepared via the solution-blending method. The analysis to determine arsenite ion adsorption was carried out using ICP-MS by varying pH, contact time and arsenite concentration parameters. The sorption of arsenite was found to be dependent on pH, time and arsenite initial concentrations. The adsorption equilibrium was reached in the first 20 min with the maximum uptake of 96%. Adsorption data were fitted well to the Langmuir isotherm describing a monolayer adsorption mechanism and pseudo-second-order models for kinetic study. It was established that the beta-CD-CS polymer blend grafted with Fe3O4 nanoparticles enhanced the adsorption capacity because of the complexation abilities of the multiple OH and NH2 groups in the polymer backbone with metal ions. Subsequently, the mechanism of adsorption was investigated by studying the physicochemical properties of the adsorbent and the adsorbed species using the FTIR, TGA, DSC, XRD, SEM and TEM techniques. The characterizations before and after incorporations of the beta-CD-CS composite with Fe3O4 nanoparticles showed well-improved properties for better adsorption of arsenite (As(III)) ions.