Treatment of Common Effluent Treatment Plant Wastewater in a Sequential Anoxic-Oxic Batch Reactor by Developed Bacterial Consortium VN11.

A laboratory-scale anoxic-oxic sequential reactor system was seeded with acclimatized mixed microbial consortium for the treatment of common effluent treatment plant (CETP) wastewater having 7000-7400 mg L(-1) of COD and 3000-3400 mg L(-1) of BOD. Initially, CETP wastewater was treated under anoxic reactor at 5000 mg L(-1) of MLSS concentrations, 5.26 ± 0.27 kg COD m(-3) day(-1) of organic loading rate (OLR) and 36 h of hydraulic retention time (HRT). Further, the effluent of anoxic reactor was treated in oxic reactor with an OLR of 6.6 ± 0.31 kg COD m(-3) day(-1) and 18 h HRT. Maximum color and COD removal were found to be 72 and 85 % at total HRT of 2.25 days under anoxic-oxic sequential reactor at 37 °C and pH 7.0. The UV-VIS, FTIR, NMR and GCMS studies showed that majority of peaks observed in untreated wastewater were either shifted or disappeared after sequential treatment. Phytotoxicity study with the seeds of Vigna radiata and Triticum aestivum showed more sensitivity toward the CETP wastewater, while the products obtained after sequential treatment does not have any inhibitory effects. The results demonstrated that the anoxic-oxic reactor fed with bacterial consortium VN11 could bring about efficient bioremediation of industrial wastewaters.