Modified chitosan gel incorporated with magnetic nanoparticle for removal of Cu(II) and Cr(VI) from aqueous solution

A novel adsorbent material for removal of metal ion from aqueous solution was made by modification of chitosan. Schiff base prepared from reaction of chitosan with 3-methyl-1-phenyl-5-(piperidin-1-yl)-1H-pyrazole-4-carbaldehyde was crosslinked with epichlorohydrin to form a crosslinked gel. Fe₃O₄ nanoparticles were incorporated into the modified chitosan gel to obtain a magnetic adsorbent material. The magnetic nanocomposite thus obtained was characterized using FTIR, TGA, SEM, EDS and XRD techniques and evaluated for adsorptive removal of Cu(II) and Cr(VI) ions from aqueous solutions. The maximum adsorption capacity of the adsorbent for Cu(II) and Cr(VI) ions was found to be 90.90 and 83.33 mg g^-1 respectively. The adsorption data fitted well with Langmuir isotherm model and the pseudo-second order kinetic model. Thermodynamic parameters indicated the adsorption to be spontaneous and endothermic. The desorption studies revealed the efficient recovery of adsorbate species and possible reusability of the adsorbent material.