Treatment of dye house effluents by a developed bacterial consortium: A shake flask study

摘要

Bacterial consortium developed for decolourising 18 different metal complex dyes was used to investigate its efficiency towards treatment of three different dye house effluents E-1, E-4 and E-5(DHEs). Process was optimised at shake flask level for the pH, temperature, culture condition, carbon and nitrogen source. The developed consortium showed better decolourisation of the DHEs under static condition compared to shaking condition between pH 6-10 and 25-45°C temperature. Decolourization was positively influenced by the addition of glucose, sucrose, maltose and starch in case of E-1, whereas E-5 was found to be better decolourized by supplementation of beef extract to the basal medium. However, E-4 showed variable decolourization pattern with <60% decolourization irrespective of carbon and nitrogen sources used. Decolourization and degradation profiles of all the 3DHEs were studied to optimize treatment time. Reduction in BOD, COD and American Dye Manufacturers' Institute (ADMI) values were in the range of 60-85% except for E-4 where BOD and ADMI removal was in the range of 75-90%, but rest of the other parameters were reduced in the range of 20-60% which were lost. Moreover, FTIR and HPLC spectral data analysis and enzyme induction pattern confirmed biodegradation of all the DHEs. Considerable amount of intracellular azoreductase, NADH-DCIP reductase and laccase productions were detected, which played significant role in degradation. Reduction in phyto- and microbial toxicity was found in the range of 70-100% and 40-53%, respectively which indicated detoxification of the wastes. The findings indicate that the developed bacterial consortium can be used for bio tretament of recalcitrant DHEs.