MICROBIAL PROCESS FOR TREATMENT OF PHENOL BEARING DYE - INDUSTRY EFFLUENT IN A FIXED-FILM BIOREACTOR

Microbial process developed to treat waste effluent arising from dye-i ndustry manufacturing methyl violet, rhodamine B, nigrosine and chryso idine was evaluated at site of the factory in a fixed film bioreactor. A culture of Pseudomonas alcaligenes, isolated from cattle dung by ad aptation to the waste effluent was immobilized on rock media packed in a rectangular steel tank of 1.93 m(3) capacity. The effluent was trea ted by recycling it for 24 h in the form of a shower through rock medi a at a 7 day Hydraulic Retention Time (HRT) at an influent loading rat e of 0.055 m(3)/m(2) stone bed area per day. The phenol and COD loadin g rates were 0.035 kg phenol/m(2)/day and 0.305 kg COD/m(2)/day respec tively. The microbial treatment resulted in the removal of 51% COD, 82 % BOD, 74% TOC (Total Organic Carbon), 76% phenol, 67% acetic acid and 60% colour in terms of methyl violet. The pH of the waste effluent re mained stable at 8.02. Thus, using a culture of Pseudomonas sp., pheno l bearing effluent from a dye-industry could be treated in a fixed fil m bioreactor.