Cationic starch as a flocculating agent in the wastewater treatment industry - A review

Starch and its derivatives have proven their usefulness in flocculation processes. Among these derivatives, cationic starch has been widely used in the water treatment industry as a suspending agent and surface absorption processes. Cationic starch is synthesized by adding chemical materials with certain cationic groups to natural starch. Cationic starches have long been used as additives in papermaking to improve mechanical strength and provide better and faster shelf-life properties. This review briefly discusses the recent studies on the synthesis, structure and mechanism of surface adsorption in cationic starch flocculants. The most important use of flocculants is in water purification. Water treatment facilities use coagulants to neutralize charged particles suspended in water. This study also describes conventional synthetic processes and cation substitutions of cationic starches and addresses their current and potential applications in flocculation. In addition, the effect of structural and operational parameters on the mechanism and extent of cationic starch surface absorption has been investigated, especially in the case of microorganisms. All the mentioned studies have been investigated with the aim of expressing the high ability of cationic starches in the direction of flocculation and wastewater treatment with efficient and cost-effective performance.