Adsorption of Cd(II) using Polyacrylamide/Rice Husk Hydrogel

Abstract

Rice husk is an abundant by-product from rice milling in agricultural countries and has potential as an adsorbent of toxic heavy metals. The rice husk powder was grafted into the acrylamide polymerization process in an aqueous solution. FTIR spectroscopy revealed critical functional groups that play roles in binding metal ions. Removal of 93% of Cd ions in aqueous solution was found at the initial concentration of 600 mg/L. A batch study of the adsorption isotherm process of cadmium ions using Langmuir and Freundlich models was suitable with both models, but Langmuir was more fitted with the data based on a higher R2 value. This result suggests that polyacrylamide-grafted rice husk hydrogel has the potential for heavy metal removal in an aqueous solution.