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Updated: May 29, 2026

Preparation of Expanded Chitin Foams and their Use in the Removal of Aqueous Copper
Published on: February 27, 2021
Interaction of carboxymethylchitosan and heavy metals in cement media
M Lasheras-Zubiate1, I Navarro-Blasco, J I Alvarez
1Department of Chemistry and Soil Sciences, University of Navarra, Irunlarrea, 1, 31008 Pamplona, Spain.
Abstract:
The performance of an etherified chitosan, carboxymethylchitosan (CMCH), when added to cement mortars doped with heavy metals, was assessed. In the presence of heavy metals (Cr, Pb, Zn) strong modifications of the fresh-state properties were evaluated. The addition of the polymer was seen to be useful in minimising some of these modifications, as those related to the setting time. A competitive mechanism for adsorption between the oxoanionic form of the metals and the carboxylate groups of the chitosan derivative was established. Studies on the metal chelating ability of the polymer and leaching from the hardened specimens showed scarce complexation under alkaline conditions, pointing to physical entrapment based on metal adsorption. However, significant chelation of metals was proved at near-neutral pH, suggesting the potential usefulness of the polymer as an agent for removing heavy metals from polluted waters and subsequently immobilizing them in cement mortars. Leaching tests carried out on polymer-metal complex-bearing samples showed a reduction in the amount of released Pb and Zn.
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