Spherical Chitosan/Gelatin Hydrogel Particles for Removal of Multiple Heavy Metal Ions from Wastewater

This article describes a simple preparation of chitosan/gelatin (CG) spherical hydrogel particles for the effective removal of multiple heavy metal ions. The CG hydrogel particles were prepared by inverse emulsion from the aqueous solutions of chitosan, gelatin, and glutaraldehyde. The oven-dried C2G1 hydrogel particles showed a maximum removal efficiency of 98% for Hg(II) ions in a single metal ion solution and which was higher than C1G1 (85%) and C1G2 (58%) particles. This result was affected by the composition of the hydrogels rather than the pore size or degree of swelling. Remarkably, the removal efficiencies for the Pb(II), Cd(II), Hg(II), and Cr(III) ions reached about 73%-94% in a multiple metal ion solution. The results indicate that the CG hydrogel particles can be used to remove coexisting heavy metal ions from wastewater, providing a versatile method to remove multiple metal ions from natural or industrial wastes.