Adsorption behavior of chitosan-based polymers templated by metal ions on mixed solutions containing Cu+2, UO2+2, Pb+2, and Co+2 ions

Abstract

Chitosan-based chelate resins having highly selective adsorption properties toward specific metal ions were prepared through a ternplated method using chitosan and metal ions as templates. Template metal ions, Cu(I I) and U(VI), were added respectively to the solution of a chitosan ligand, which was treated with 10 aqueous acetic acid in view of forming chitosan-metal chelates. The chitosan-metal complex solutions were crosslinked using a reaction with glutaraldehyde to obtain crosslinked chitosan-metal chelate polymers. The metal chelate polymers were treated with 1 M HCl to remove metal ions, followed by alkali and distilled water treatments. The products were cross linked-chitosan polymers containing Cu(II) and U(VI), respectively; they showed highly selective adsorption properties toward their metal ion templates from a mixture of Cu+2, UO2+2, Pb+2, and Co+2 in solution. Adsorption was also measured for the crosslinked chitosan without a template metal ion. It was found that the adsorption properties in mixture solutions were greatly enhanced toward metal ions of the same kind as that used as the template; however, it was lower for the resins prepared without the use of metallic template ions.