PHYSICO-CHEMICAL TREATMENT OF KATTHA MILL WASTEWATER

Abstract

Kattha is solidified water extract of the heart wood of trees of "Khair". Kattha manufacturing has been developed gradually from ancient times and still carried on largely as a cottage industries. Till last decade no scientific attention had been paid to its manufacturing' process. Now in India there are over 24 full-fledged factories, manufacturing Kattha, with annual turn over of well over. Rupees 20 Crores. Wastewater from Kattha industry is ,characterised by strong colour (Red brown) and high COD. Unfortunately very little work has been done to reduce pollution hazards created by these factories. Hence an attempt was made to study the reduction of these pollutants with the help of chemical coagulants (Shivayo(:)imath, 1988). In this work some natural- polyelectrolytes have been tried to see their efficiency to remove pollutants (colour and COD) from Kattha wastewater. Wastewater samples were collected from a factory in Nazibabad (U.P.). Batch studies on laboratory scale were conducted to find the efficiency of various natural polyelectrolytes. Prom these studies it was found that these polyelectrolytes are able to remove colour and COD effectively when used as a coagulants but Alum is required with each coagulants to settle the flocs formed. It shows that flocs formed with natural polyelectrolyte•s are too light to settle in reasonable time. It was also revealed that out of three natural polyelectrolytes (Soya flour, Gwar seeds flour and Nirmali Seeds flour) and one chemical (Bleaching powder), only Nirmali seeds were not effective for Kattha waste-water. As far as colour and COD removal are concerned Soya flour gave the best results in conjunction with Alum.