Seed gum polysaccharides and their grafted co-polymers for the effective coagulation of textile dye solutions

In view of easy availability of the plant and high demand of seed gums throughout the world, the present investigations have been carried out for possible exploitation of Ipomoea seeds as potential source of commercial gum. Graft co-polymerization with acrylamide was done to modify the seed gums for the favourable properties. The aqueous solutions of three highly colored different anionic dyes (reactive, acid and direct dye) were taken for decolorization studies. Although synthetic polyelectrolytes like polyaluminium chloride (PAC) provide better dewatering characteristics in the sludge produced, their long-term effects on human health is not well understood. The role of natural seed gums and their grafted co-polymer on color removal was investigated by comparing two treatments: (i) PAC alone and (ii) PAC/seed gum in combination. The seed gums and their grafted co-polymers were found to be good working substitutes alone as well as in conjunction with a very low dose of PAC, for the decolorization of the dyes in varying ratios. Compared to PAC alone treatment, the use of seed gum as coagulant aids in combination with PAC was highly efficient in color removal. The results indicate that the use of seed gums as aids with PAC could be a very beneficial system in dye wastewater treatment. (c) 2007 Elsevier Ltd. All rights reserved.