Carboxymethyl Chitosan Derivatives and Its Interaction with Metal Ions.

Chitosan (CS) is a non-toxic, biocompatible, and biodegradable deacetylated derivative of chitin. CS was effective metal-chelator; however, its practical application is restricted because of adsorption capacities, stability in acid medium, and adsorption selectivity. Because of the existence of amine (-NH2) and hydroxyl (-OH) groups, CS could be altered to make different derivatives with varying solubility pattern. Chitosan chemical modification and its derivatives by graft copolymerization could improve their properties and as a result expand their promising applications onto various fields. Carboxymethyl chitosan is one of the chitosan derivatives and it was most intensively explored because of its water solubility in broad pH conditions. However, it was employed in various promising applications. Carboxymethyl chitosan (CMCS) has soluble nature, hence it is difficult to use for metal ion removal studies. To overcome this problem, carboxymethyl chitosan was modified as insoluble hybrid material and was utilized for heavy metal removal studies by adsorption method. In this review, CMCS derivatives and its interaction with heavy metal ions were investigated in detail. It is hopefully predictable that the content will offer conclusive insights on the utilization of this biological activity, biodegradation, low-toxicity, and biocompatibility of CMCS and its interaction with various heavy metals for water purification and trust to boost up its promising application as heavy metals removal. [ABSTRACT FROM AUTHOR]