Bioremediation of color and COD from dye effluent using indigenous and exogenous microbes

摘要

Dye effluents pose severe environmental hazards. Devising cost-effective and eco-friendly techniques for treating wastewater containing dye effluent is the need of the day. The intention of the present study is to expose a technique for decolorizing the dye effluents, for degrading the contaminants present in the effluent and for minimizing the COD below standard limits. The dye effluent samples collected for the present study characterize a high COD of 972 mg/L, pH 8.6 and highly objectionable color (990 Hazen Units). The predominant indigenous organisms present in the samples were isolated and identified as Aspergillus niger and Aspergillus flavus. Potential exogenous organisms Trichoderma viride and Aspergillus fumigatus were obtained, and these organisms were used to conduct treatability studies. An up-flow immobilized column reactor (UFICR) was designed and used to treat the textile effluent. The shaker flask trials give maximum decolorization efficiency of 91% and COD reduction of 84%. The reactor studies showed elevated efficiencies of 92.7% and 93% efficiency in decolorization and COD reduction, respectively. The present study is developed as an efficient strategy to replace the less eco-friendly physicochemical approaches and also to provide a better insight into the field of bioremediation and its role in the treatment of dye effluent.