Biodegradable brag reducing agents and flocculants based on polysaccharides: Materials and applications

Organic and inorganic flocculants are used in treatment of water and indust rial effluents. Polymeric flocculants, synthetic as well as natural, becaus e of their natural inertness to PH changes, low dosage, and easy handling. have become very popular in industrial effluent treatment. It has been esta blished in the authors' laboratory that by grafting polyacrylamide branches on rigid backbone of polysaccharides, the dangling grafted chains have eas y approachability to contaminants in effluents. Thus grafted polysaccharide s are very efficient, shear stable and biodegradable flocculants. They also exhibit turbulent drag reducing characteristics. Among grafted guar gum, x anthan gum, carboxymethyl cellulose, and starch, grafted starch performs th e best. Starch consists of amylose (a low molecular weight linear polymer) and amylopectin (a high molecular weight, branched polymer). The grafted am ylopectin is found to be the best flocculant for various kinds of industria l effluents, providing credibility to the above-cited model. In the present paper. the details about grafted polysaccharides as turbulent drag reducer s and flocculants are given, along with their applications.