MICROBIAL TECHNOLOGY FOR MANAGEMENT OF PHENOL BEARING DYESTUFF WASTE-WATER

Environmental pollution caused by dyestuff industry wastewater is two- fold since it contains toxic chemicals like phenol, aniline etc. and a lso imparts the colour of the dye manufactured. For management of dyes tuff wastewater, microbial technology becomes a novel approach since m icroorganisms have the characteristic ability to break down aromatic c ompounds and decolourize the dyes. Microbial treatment of a dyestuff w astewater containing phenol and methyl violet was studied at the site of a dye factory near Pune in a fixed film bioreactor. The bioreactor consisted of a rectangular cement concrete tank of dimensions 9.5 m le ngth x 7.3 m breadth x 1.5 m height and brick pieces of size 10 cm x 8 cm x 6.5 cm used as supporting media for formation of microbial film. A mixed culture of Pseudomonas alcaligenes (phenol degrader) and Pseu domonas mendocina (decolourizing methyl violet) grown in the dyestuff wastewater was spread on brick media. After formation of a microbial f ilm on brick media, the dyestuff wastewater was recycled in Form of a shower through the brick bed for 24, 48 and 72h. The influent loading rate was 1.44 m(3)/m(2) brick bed area per day. The phenol and Chemica l Oxygen Demand (GOD) loading rates were on average 0.9 kg phenol/m(2) /day and 5.67 kg COD/m(2)/day respectively. The performance of the mic robial degradation evaluated for a period of 68 days showed 97.5%, 63% , 54.4% and 51% removal in phenol, methyl violet (MV) content, COD and Total Organic Carbon (TOC) respectively in 24 hours of recycling and marginally enhanced in 48 and 72 hours. The microbial technology was t hus effective in removal of phenol and the dye from dyestuff wastewate r. Copyright (C) 1996 IAWQ. Published by Elsevier Science Ltd.