Treatment of textile wastewater containing mixed toxic azo dye and chromium (VI) BY haloalkaliphilic bacterial consortium

Scientific empowerment in this century created a positive and negative impact on the ecosystem's biotic and abiotic components. The current scenario of emerging recalcitrant pollutants in the environment is encountered using various remediation approaches are enforced and applied. The need for mineralization of the toxic pollutants to non -toxic forms accomplished the application of microbes (bacteria, fungi and algae) and plants individually or in a combined manner. The current research on the removal of pollutants from synthetic textile wastewater containing 1200 ppm concentration of mixed azo dyes -Reactive red (RR), Reactive Brown (RB) & Reactive Black (RBl) and 300 ppm Cr (VI) metal using haloalkaliphilic bacterial strains LBKVG1, LBKVG2, LBKVG3 & LBKVG4 in a Moving Bed Biofilm Reactor (MBBR), showed decolorization of 82 +/- 0.5% of mixed azo dyes and degradation 56 +/- 0.5% of Cr (VI) metal at 37 degrees C and pH 8.5 in the fifth day of the study. The isolated bacterial strains in the consortium were molecularly and morphologically characterized by 16SrRNA sequencing and SEM analysis. FT-IR and GC-MS analysis scrutinized the metabolites obtained. The findings suggest the degradation of hazardous pollutants even at higher concentrations and attempt to decolourize the mixed azo dyes simultaneously using the eco-friendly bacterial consortium.

Automated summary

This study examined the removal of mixed azo dyes and Cr(VI) metal in synthetic textile wastewater using haloalkaliphilic bacterial strains in a Moving Bed Biofilm Reactor. The results showed efficient decolorization of dyes and degradation of the metal, even at higher concentrations, by the eco-friendly bacterial consortium. Molecular and morphological characterization of the bacterial strains, along with analysis of metabolites, supported the findings of hazardous pollutant degradation and simultaneous dye decolorization.