Sorption of heavy metal ions onto carboxylate chitosan derivatives-A mini-review

Chitosan is of importance for the elimination of heavy metals due to their outstanding characteristics such as the presence of NH2 and -OH functional groups, non-toxicity, low Cost and, large available quantities. Modifying a chitosan structure with -COOH group improves it in terms of solubility at pH <= 7 without affecting the aforementioned characteristics. Chitosan modified with a carboxylic group possess carboxyl, amino and hydroxyl multifunctional groups which are good for elimination of metal ions. The focal point of this mini-review will be on the preparation and characterization of some carboxylate chitosan derivatives as a sorbent for heavy metal sorption. (C) 2015 Elsevier Inc. All rights reserved.