Document Type : Research Paper


Department of Applied Science, Division of Biotechnology, University of Technology - Iraq


Industrial and agricultural discharges have been shown as important sources for a wide range of contaminants like heavy metals. This study focused on the assessment of the toxic effect of heavy metals and illustrates some methods of eliminating or avoiding these contaminants. In certain methods, heavy metals (Cu, Zn, Cr, Ni, Pb, Hg, and Cd) are recovered, and range of absorbents are tested. A number of studies have reported the complex interaction of polymers with metal ions with the polymers for eliminating heavy metals (e.g. cellulose, chitosan, and chitin. Metal ions are absorbed by these polymers by the amine and hydroxyl groups. They have unique features that incorporate polyxysalt arrangement, capacity to frame films, optical underlying qualities, and chelates metal particles. Chemical bonds, pH, crystallinity, and deacetylation are controlling the mechanism and performance of the absorption. Some methods increase the efficiency, selectivity, and quality of chitosan: the first is through chemical modification employing grafting and crosslinking, and the second by physical modification, such as manufacturing gel granules and reducing crystallization. This study aims to investigate the removal of heavy metals from water by the sorption method and to study and analyze literature dealing with this topic using chitosan hydrogel.