Magnetic chitosan hydrogel beads as adsorbent for copper removal from aqueous solution

Abstract

Magnetic chitosan hydrogel beads (MCHB) were synthesized by blending chitosan and magnetite (Fe3O4) in sodium alginate solution. The MCHB was used to remove Cu (II) metal ions in an aqueous solution. The performance of MCHB to remove Cu (II) ions was evaluated experimentally at different parameters (the initial pH of the solution, contact time, and various magnetite ratios of the hydrogel beads) in the batch adsorption set-up. This study indicated that MCHB managed to remove Cu (II) ions by adsorption at pH 5 at 24 h of contact time. The hydrogel beads of MCHB-0.5 (C:M:A ratio by weight of 1:0.5:2) show the highest Cu (II) ions removal efficiency of 56.51%. The addition of magnetite at the minimal ratio does not hinder the adsorption of Cu (II) ions onto MCHB. The magnetite in the beads also eases the separation of the hydrogel beads from the solution by an external magnet after treatment.