Investigation On Flocculation Characteristics Of Cationic Polysaccharides: Novel Polymeric Flocculants

摘要

The anionic, cationic and nonionic polymeric flocculants, which are endowed with several distinguished characteristics, are increasingly being applied to the treatment of industrial effluents, municipal and wastewaters. In the authors' laboratory, research has been conducted by purifying and chemically modifying the various industrial polysaccharides such as amylopec-tin, amylose, carboxymethyl cellulose, glycogen, guar gum, hydroxypropyl guar gum, sodium alginate, starch, xanthan gum etc. When these polysaccharides are grafted with polyacryla-mide chains, the flocculation characteristics are synergistically increased. Grafted on rigid polysaccharides, dangling polyacry-lamide branches have easy approachability to contaminants in industrial effluents and are responsible for synergistic increases in their flocculation characteristics. On optimal hydrolysis of these grafted polysaccharides, their flocculation and viscosifying characteristics are enhanced drastically. These grafted and hydrolyzed grafted polysaccharides are mainly nonionic and anionic in nature and are efficient flocculants for the treatment of industrial effluents of relatively low negativity. But for the treatment of highly negatively charged particle suspensions, cationic flocculants are more efficient.