Dyes are the visible contaminants that are released from the textile industries. Bioremediation of textile dye effluents using microbes is one of the greener methods owing to their degradation potential of varied range of pollutants. Bacteria, fungi, yeast and algae have synergistic metabolic activities that alter the chromogen and degrade the absorbed dye colour. This work was aimed at investigating the dye decolorization potential of a mixed microbial culture (MMC) obtained from different soil and sludge samples. A single dye (Direct Blue 53) was used for comparison studies. The mixed microbial cultures were incubated for 9 d in mineral salt medium (MSM) with dye and the absorbance of its filtrate at 647nm (Blue dye) and 308nm (Industrial dye) was noted down for every 22 h. The colour removal efficiency (CRE) by MMC were 47.04% , 46.77% , 45.21% and 35.02% for soil of textile dyeing unit (DS), sludge from STP (SE) soil (SS) from drying bed of STP and sludge from membrane reactor of dyeing unit (DE) respectively. Further, the maximum CRE of 98.35% was recorded by microbial culture from drying bed soil of STP (SS), followed by microbial culture from STP sludge (SE) was 97.96%, textile dyeing unit soil (DS) of 96.99%, and sludge form membrane reactor of dyeing unit (DE) was 96%. Bacillus sp. isolated from eco-bio block was tested against the blue dye and gave colour removal of about 89.25%. From this study, it is observed that the microbe present in soil obtained from the dyeing unit is naturally acclimatised to the dye waste and hence shows highest removal.
Key words: Biodegradation, decolourization, textile dyes, mixed microbial culture, biosorption
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