Decolorization and Degradation of Reactive Dyes by Aspergillus niger

Environmental pollution is one of the major problems of the modern world. Synthetic dyes are extensively used in textile dyeing, paper printing, colour photography, pharmaceutical, food, cosmetics and other industries. Conventional wastewater treatment plants are unable to perform a complete dye removal, 90% of reactive textile dyes persist after activated sludge treatment. Currently, various chemical, physical and biological treatment methods are used to remove color. This study focuses on the biological decolourization of textile effluents through microbial isolates obtained from contaminated sites. The dye effluent samples and soil sample from the dye contaminated sites were collected from CETP, Perundurai. Totally 3 different effluent and soil samples were collected. The isolation of fungal colony from these samples was then carried out and identified as Aspergillus niger. For decolorization studies, three synthetic dyes namely Reactive Red 120 and Reactive Black 5 used and these dyes were prepared at a concentration of 50 mg/100 ml and the decolorization assay mixture consists of 10% of dye. The optimization of the decolorization efficiency was then carried out for the screened fugal isolates. The effect of pH, Temperature, C: N ratio and shaking conditions were studied and these parameters are optimized to obtain maximum decolorization of the commercial dyes using the fungal colonies.