Promoted biodegradation of para-ester wastewater by electrostimulated ZVI assisting novel UBF/ceramic membrane MBR and microbial community

Abstract

A novel electrostimulated ZVI-assisting functional ceramic filter -UBF/ceramic membrane MBR was evaluated for possessing low COD/(sulfate plus organic sulfur) high-strength para-ester wastewater in terms of COD, NH4+-N abatement and para-ester degradation. The porous functional ceramic filter was prepared as new biofilm material in the novel UBF. The 200 days' successive operation indicated that the combined UBF system is an on-site upgrading anaerobic technology for methanogenesis, gaving a satisfied performance even at a COD/(sulfate plus organic sulfur) ratio as low as 1.57 with OLR up to 6.8 g COD/L/day. Bacteroidetes, Chloroflexi, Firmicutes and Proteobacteria phyla were prevalent on day 200. The appearance of the Mesotoga genus can in charge of the para-ester degradation. Desulfovibrio with a relative abundance of 2.68% was the dominant sulfate-reducing bacterium (SRB) followed by Desulfarculus. The ceramic membrane MBR was then fed with the UBF effluent at a COD/(sulfate plus organic sulfur) of 1.57 at the optimal OLR. After 75 days of operation, the final effluent quality with a COD, para-ester, and NH4+-N of 171 mg/L, 22 mg/L and 27 mg/L, respectively, was discharged up the standard required. The result suggested the potential applicability of the integrated system in treating para-ester wastewater.