Amylopectin grafted with poly (acrylic acid): Development and application of a high performance flocculant

• A novel polymeric flocculant has been synthesized based on amylopectin and poly (acrylic acid).
• The graft copolymer is a useful flocculant for treatment of synthetic effluent as well as mining industry wastewater.
• Graft copolymer, having highest hydrodynamic radius is the best flocculant.
• The developed flocculant showed excellent colour removal property from mining industry wastewater.

In recent years, wastewater treatment, especially for wastewaters which are not suitably recycled by conventional or normal biological processes, is getting more importance. Of late, natural biopolymer based flocculants are extensively used for wastewater treatment because of low cost, environment-friendly and easily availablility from reproducible farm and forest resources. This article introduces the development of a natural polymer based flocculant [amylopectin grafted with poly (acrylic acid) – AP-g-PAA] for treatment of synthetic effluent as well as mining industry wastewater. The graft copolymer based flocculants have been developed under optimum conditions and characterized using viscometry, 13C NMR, SEM, TGA, rheological characteristics, determination of hydrodynamic radius and CHN analysis. The flocculation characteristics of grafted and ungrafted polysaccharide have been evaluated in synthetic effluents (as Fe-ore, kaolin, Mn ore suspensions) as well as in mining industry wastewater.