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-industry manufacturing methyl violet, rhodamine B, nigrosine and chrysoidine was evaluated at site of the factory in a fixed film bioreactor. A culture of Pseudomonas alcaligenes, isolated from cattle dung by adaptation to the waste effluent was immobilized on rock media packed in a rectangular steel tank of 1.93 m(3) capacity. The effluent was treated by recycling it for 24 h in the form of a shower through rock media at a 7 day Hydraulic Retention Time (HRT) at an influent loading rate of 0.055 m(3)/m(2) stone bed area per day. The phenol and COD loading rates were 0.035 kg phenol/m(2)/day and 0.305 kg COD/m(2)/day respectively. 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 remained stable at 8.02. Thus, using a culture of Pseudomonas sp., phenol bearing effluent from a dye-industry could be treated in a fixed film bioreactor.