Study on adsorption, regeneration, and reuse of crosslinked chitosan graft copolymers for Cu(II) ion removal from aqueous solutions

Abstract

A B S T R A C TThis study deals with the adsorption, regeneration, and reuse of chitosan-graft-itaconic acid and chitosan-graft-crotonic acid beads for Cu(II) ion removal from aqueous solutions. For this aim, adsorption capacities, adsorption kinetics, and adsorption isotherms of these crosslinked chitosan-graft-copolymeric beads were investigated in detail. The maximum adsorption capacities of chitosan-graft-itaconic acid and chitosan-graft-crotonic acid beads were found to be 0.31 and 0.25 mmol/g, respectively. In addition, it was found that the pseudosecond-order kinetic model is more suitable than pseudo-first-order model for the adsorption of Cu(II) ions onto the beads according to adsorption kinetics data. Adsorption isotherm data were evaluated using Freundlich, Langmuir, Brauner-Emmet-Teller, Dubinin-Radushkevich and Temkin isotherm models. The results revealed that the adsorption of Cu(II) ions onto the beads fits very well Freundlich isotherm model. Then, the beads were regenerated with an acid solution, and they were reused for adsorption of Cu(II) ions. Regeneration study results showed that, the metal ion removal capacity of regenerated beads did not change significantly in the end of the fourth regeneration period compared to the first regeneration period. It was concluded that the crosslinked chitosan-graft-copolymeric beads might be suitable adsorbent for the removal of metal ions from aqueous effluent.

Preparation of methacrylamide-functionalized crosslinked chitosan by free radical polymerization for the removal of lead ions

“…Glutaraldehyde-crosslinked chitosan was also grafted with acrylic acid by gamma ray radiation (Benamer et al, 2011). In another study, epichlorohydrin was used to crosslink chitosan and then it was grafted with crotonic acid and the product was used for the removal of heavy metals (Bal, Özkahraman, Acar, Özyürek, & Güçlü, 2013).…”

Novel High-Performance Functionalized and Grafted Bio-Based Chitosan Adsorbents for the Efficient and Selective Removal of Toxic Heavy Metals from Contaminated Water

“…Shankar et al [ 23 ] attempted to graft-copolymerize glutaraldehyde-crosslinked chitosan with acrylonitrile using cerium ammonium nitrate initiator for chromium (VI) adsorption. Bal et al [ 24 ] employed crotonic acid as an alternative monomer in the grafting copolymerization of chitosan for the efficient removal of Cu(II) ions from water.…”