Cationic starch-enhanced ultrafiltration for Cr(VI) removal

Abstract

The feasibility of cationic starch-enhanced ultrafiltration (CSEUF) was investigated to remove chromate from the aqueous stream. Cationic starch is a modified starch with cationic functional groups, which interact with anionic pollutants. For CSEUF, a cationic starch was synthesized, whose degree of substitution was 0.2 and water-insoluble. Chromate was bound spontaneously to cationic starch, after that the binding was saturated. As the concentration of cationic starch increased from 0.5 to 1.0, to 1.5, to 2.0, and to 2.5 g/l, the removal of chromate increased from 33% to 62%, to 82%, to 95% and to 98%, respectively. Based on the high removal, high flux, and biodegradability of cationic starch, CSEUF is a feasible process to remove chromate from the aqueous stream.