The analysis of microbial community in the biodegradation, electron transfer based on sulfur metabolism integrated (BESI®) process for reverse osmosis concentrate (ROC) treatment by 454-pyrosequencing

In this study, a laboratory-scale biodegradation, electron transfer based on sulfur metabolism integrated (BESI (R)) process was used on the treatment of petrochemical reverse osmosis concentrate (ROC). ROC is a type of saline wastewater with low biodegradability. In the operational days, the chemical oxygen demand (COD) and total organic carbon removal efficiencies on average were 79.18 and 79.39%, respectively. The removal efficiencies of ammonia nitrogen and total nitrogen on average were 79.84 and 83.60%, respectively. High-throughput pyrosequencing was applied on the analysis of the microbial community in activated sludge and biofilm samples. The functional phylotypes sulfate-reducing bacteria (SRB) were detected in anaerobic reactor, and they participated in the COD removal and sulfate reduction. The genera Hyphomicrobium, Azoarcus, Thauera, Paracoccus, and Nitrospira were detected in the BESI (R) process. These genera contributed to the nitrogen transformation, and they played different roles in each reactor of the integrated process.