Enhanced degradation of bisphenol A and ibuprofen by an up-flow microbial fuel cell-coupled constructed wetland and analysis of bacterial community structure

This study aims to demonstrate that an up-flow microbial fuel cell-coupled constructed wetland (UCW-MFC) can effectively treat synthetic wastewater that contains a high concentration of pharmaceutical and personal care products (PPCPs, 10 mg L-1 level), such as ibuprofen (IBP) and bisphenol A (BPA). A significant decline in chemical oxygen demand (COD) and ammonia nitrogen (NH4+-N) removal was observed when BPA was added, which indicated that BPA was more toxic to bacteria. The closed circuit operation of UCW-MFC performed better than the open circuit mode for COD and NH4+-N removal. Similarly, the removal rates of IBP and BPA were increased by 9.3% and 18%, respectively, compared with the open circuit mode. The majority of PPCPs were removed from the bottom and anode layer, which accounted for 63.2-78.7% of the total removal. The main degradation products were identified. The removal rates of IBP and BPA decreased by 14.6% and 23.7% due to a reduction in the hydraulic detention times (HRTs) from 16 h to 4 h, respectively. Electricity generation performance, including voltage and maximum power density, initially increased and then declined with a decrease in the HRT. Additionally, both the current circuit operation mode and the HRT have an impact on the bacterial community diversity of the anode according to the results of high-throughput sequencing. The possible bacterial groups involved in PPCP degradation were identified. In summary, UCW-MFC is suitable for enabling the simultaneous removal of IBP and BPA and successful electricity production. (C) 2018 Elsevier Ltd. All rights reserved.