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

• Published in: Chemosphere (Oxford) Vol. 287; p. 132280
• Main Authors: Biju, Leena Merlin, Pooshana, V., Kumar, P. Senthil, Gayathri, K. Veena, Ansar, Sabah, Govindaraju, Saravanan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-01-2022
• Subjects: Chromium; Haloalkaliphilic bacterial strains; MBBR; Mixed azo dyes; Wastewater; Chromium; MBBR; Haloalkaliphilic bacterial strains; Wastewater; Mixed azo dyes
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2021.132280

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 °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.
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•Haloalkaliphilic bacterial consortium used in the removal of mixed azo dye (RR, RB & RBl) and Cr (VI).•Batch (100–400 ppm concentration of each dye and 100–300 ppm Cr (VI)) and Reactor study (1200 ppm concentration of mixed azo dye and 300 ppm Cr (VI)) was performed.•Bacterial consortium has Bacillus circulans BPB8, Bacillus circulans HQB947, Bacillus subtilis and Terribacillus gorriensis.•Characterization was performed using UV–Vis, FT-IR & GC-MS analysis.