Fabrication, characterization and flocculation properties of starch, chitosan or cellulose based graft copolymers: A review

Wastewater treatment has been most obligatory, as food industries, pharmaceutical companies, textile mills, etc., are disposing of their wastes in water bodies. Graft copolymers, in which synthetic polymers are grafted on backbones of natural polymers of diverse sources, have come into light for contaminated water treatment. In this review article, we have mounted up various synthesis methods used, along with their corresponding mechanisms, for the fabrication of starch, chitosan or cellulose based graft copolymers. Characterization techniques that are commonly used for the confirmation of the fabricated graft copolymers have been discussed. Further, the process of flocculation, its influencing factors, and mechanisms involved in flocculation have been detailed. This review also explores the treatment of wastewater discharged from several industries, which includes toxic heavy metal ions, harmful dyes, coalmine dust, mining waste, and paper and pulp industrial middle effluent. Further, saline retention, sludge dewatering, and microalgal biomass harvesting have been detailed.