Adsorption studies on removal of Pb(II) and Cd(II) ions using chitosan derived copoymeric blend

Removal of heavy metal ions from wastewater is of crucial importance for an unpolluted environment and social wellbeing. The present study was designed to prepare a novel copolymeric blend as an efficient adsorbent using chitosan oligosaccharide for the removal of toxic heavy metals Pb and Cd. The ternary blend of Chitosan oligosaccharide (COS) - g - glycidyl methacrylate copolymer (GM)/polypropylene glycol (PPG)/bentonite (Bent) was prepared and the change in morphology was ascertained by FTIR, XRD, TGA, and SEM studies. Using the prepared ternary blend, the adsorption of heavy metals was studied through batch mode to elucidate the changes in adsorption behavior. The removal percentage of lead was 89%, which was higher than cadmium (78%). The adsorption was well fitted with Freundlich isotherm (R-2 for Pb: 0.9943 and Cd: 0.9990) and pseudo-second-order kinetics (R-2 = Pb: 0.9994 and Cd: 0.9984) with C-max 177 mg/g (for Pb(II)) and 158 mg/g (for Cd(II)) respectively. Different functional groups which were involved in the binding of the heavy metals were confirmed by SEM-EDAX and FTIR examination. Desorption studies were done using different eluents and the results exposed that the desorbing agent EDTA has great efficiency. The XRD patterns of metal adsorbed ternary blend showed the crystalline phases in their structures concluding the binding of metal ions and the renewal of an amorphous pattern of metal desorbed ternary blend revealed that the desorbed material is suitable for next cycle adsorption.