Removal of Cu2+ ions from aqueous solutions by starch-graft-acrylic acid hydrogels

Abstract

Gelatinized starch was prepared by constantly stirring a mixture of starch and water at 95 degrees C for 1 hour. Starch-graft-acrylic acid (S-g-AA) hydrogels were prepared by grafting acrylic acid ( AA) [monomer/starch (w/w) 0.5-1.5] onto gelatinized starch with ceric ammonium nitrate as initiator under nitrogen atmosphere. The surface morphology of samples was studied using a scanning electron microscope (SEM). The hydrogels were evaluated for the removal of Cu2+ ion from aqueous solutions at different pH. The concentration of Cu2+ ion in aqueous solution was kept constant at 4 mmol/L. The metal ion removal capacities changed depending on treatment time, initial pH of the solution, and monomer/starch (w/w) ratio of the S-g-AA hydrogels. Cu2+ ion removal capacities were determined by atomic absorption spectrometer (AAS).