TREATMENT OF DYE-HOUSE WASTE BY SEWAGE SLUDGE

Abstract

The effluents from dye-house pose serious environmental problems due to presence of excessive colour. These effluents decreases the transparency of the receiving water and hence reduces its self-purifying capacity. High concentration of some dyes also have a toxic effect on aquatic organisms. Textile wastewaters have been treated in variety of combinations of physical, chemical and biological operations depending upon the characteristics of the wastes. The process of chemical coagulation has been commonly used for colour removal. But this process has its own limitation as it can not be applied to basic dye effluents. Besides, operational cost of this process are quite high. The present work studies the feasibility of tratment of basic dye wastes by sewage sludge. Two synthetic dye wastes have been studied to determine the degree of CoD and colour removal by sewage sludge.The experiments were conducted to determine the effect of dye concentration, sewage sludge dosage and pH on treatability of the wastes. For both the dyes, it was found that the degree of CoD and colour removal increased with increase in sewage-sludge concentrations upto 100 gm/1 thereafter, the treatabiity decreased. The efficiency of treatment was maximum at a pH of 8.