Hollow-fiber membrane bioelectrochemical reactor for domestic wastewater treatment

BackgroundMicrobial fuel cells (MFCs) are potentially advantageous as an energy-efficient approach to wastewater treatment; however, the quality of the MFC effluent has not been well addressed. In this study, a membrane bioelectrochemical reactor (MBER) was developed through integrating hollow-fiber ultrafiltration membranes into a tubular MFC to improve the effluent quality. ResultsThis MBER was operated with an acetate solution or domestic wastewater (primary effluent) for more than 200 days. The MBER removed 43-58% of total chemical oxygen demand (COD) from the acetate solution and achieved 30-36% coulombic efficiency. When treating the wastewater, the MBER was able to maintain almost 90% COD removal and an effluent turbidity <1 NTU. A strategy of periodic backwash and membrane relaxation led to a slow increase in the transmembrane pressure (TMP) from zero to 15 kPa in more than 40 days at hydraulic retention time (HRT) 36 h. However, both lower HRTs and high organic loading rates rapidly increased the transmembrane pressure. ConclusionA proof of concept of an MBER was presented and shown to be effective in contaminant removal. Preliminary energy analysis suggests that the MBER could theoretically produce sufficient energy from the acetate solution to support the pumping system. These results demonstrate the feasibility of the MBER concept and the challenges for further development of the MBER system. (c) 2012 Society of Chemical Industry