Removal of heavy metal using poly (N-vinylimidazole)-grafted-carboxymethylated starch

Carboxymethyl starch (CMS) grafted with N-vinyl imidazole was investigated for heavy metal removal from aqueous solutions. Poly (N-vinyl imidazole)-grafted carboxymethyl starch (PVI-g-CMS) was prepared in aqueous solution using potassium persulfate (KPS) as initiator. The produced grafted copolymer was characterized by FTIR, TGA, surface area and elemental analysis. The grafted material was used for the sorption of Mn(II), Zn(II) and Cd(II). Uptake parameters such as affinity of metal ions, effect of metal ion concentration, adsorbent amount and agitation time were investigated. The polymers were more sensitive to CdII and ZnII and the order of metal ion binding was Cd(II) > Zn(II) > Mn(II). The adsorption data was fitted very well in a Freundlich isotherm equation and the kinetics of adsorption was found to follow the pseudo-first order kinetic model.