Decolorization and phytotoxicity reduction of reactive blue 40 dye in real textile wastewater by active consortium: Anaerobic/aerobic algal-bacterial-probiotic bioreactor

Abstract The textile dyeing and printing industries has led to extensive environmental pollution and severely threatens ecosystems. The best microbial species for such application was selected among the isolated bacterial populations by conducting CI Reactive Blue 40 (CI RB 40) batch degradation studies with the bacterial-algal-probiotic strains. In this study, three suitable species (Pseudomonas putida, Chlorella and Lactobacillus plantarum) were applied to degrade and detoxify CI RB 40, a reactive diazo dye in Real Textile Wastewater, used in textile dyeing industry worldwide. Process parameters were optimized using Response Surface Methodology and under the optimum conditions (e.g., inoculum size of 10%), temperature of 35 °C, 150 ppm, and time of 6 days). The maximum COD and color removal efficiencies, when tested with 1000 ppm dye using batch reactors were found to be 89% and 99%, respectively. Our results showed also that bacteria had a high decolorization capacity. The regression analysis revealed a good match of the experimental data to the second-order polynomial with a high coefficient of determination (R2). UV–Visible and FTIR spectroscopy analysis confirmed the biodegradation of CI RB 40. Finally, toxicity of CIRB 40 before and after biodegradation was studied and confirm the detoxification of CIRB 40 dye solution after biodegradation process.