Treatment of textile effluent in a developed phytoreactor with immobilized bacterial augmentation and subsequent toxicity studies on Etheostoma olmstedi fish

Graphical abstract: - Highlights: • A phytoreactor was developed and augmented with immobilized bacteria. • This consortium showed enhanced treatment than the individual species. • Oxido-reductases from P. crinitum and B. pumilus could decolorize the effluent. • Characterization of effluent samples endorsed the efficacy of consortial strategy. • Toxicity studies revealed the less toxic nature of the consortium treated effluent. - Abstract: A static hydroponic bioreactor using nursery grown plants of Pogonatherum crinitum along with immobilized Bacillus pumilus cells was developed for the treatment of textile wastewater. Independent reactors with plants and immobilized cells were also kept for performance and efficacy evaluation. The effluent samples characterized before and after their treatment showed that the plant–bacterial consortium reactor was more efficient than those of individual plant and bacterium reactors. COD, BOD, ADMI, conductivity, turbidity, TDS and TSS of the textile effluent was found to be reduced by 78, 70, 93, 4, 90, 13 and 70% respectively within 12 d by the consortial set. HPTLC analysis revealed the transformation of the textile effluent to new products. The phytotoxicity study on Phaeseolus mungo and Sorghum vulgare seeds showed reduced toxicity of treated effluents. The animal toxicity study performed on Etheostoma olmstedi fishes showed the toxic nature of untreated effluent giving extreme stress to fishes leading to death. Histology of fish gills exposed to treated effluent was found to be less affected. The oxidative stress related enzymes like superoxide dismutase and catalase were found to show decreased activities and less lipid peroxidation in fishes exposed to treated effluent