ENHANCEMENT OF THE METAL-BINDING PROPERTIES OF CHITOSAN THROUGH SYNTHETIC ADDITION OF SULFUR-CONTAINING AND NITROGEN-CONTAINING COMPOUNDS

Several new chitosan derivatives were synthesized with the intent of f orming polymers that could be used in hazardous waste remediation as t oxic metal-binding agents in aqueous environments. The ability of thes e derivatives to bind Cu2+, Pb2+, Cd2+, and Fe2+ was tested and compar ed to chitosan. Four of the new compounds, the products of the reactio n of chitosan with mercaptosuccinic acid, thiirane, pyridoxal hydrochl oride, and succinamide, show promising results as binding agents for t he above metal ions. The compound with mercaptosuccinic acid bound twi ce as much Cd2+, five times as much Pb2+, and virtually no Fe2+ when c ompared to chitosan. The compound with thiirane bound three times as m uch Pb2+, whereas the pyridoxal hydrochloride derivative bound 30% mor e Cu2+ and twice the Pb2+. The succinamide derivative gave results com parable to chitosan, but with decreased solubility at low pH.