Electricity generation and microbial community in a submerged-exchangeable microbial fuel cell system for low-strength domestic wastewater treatment

• Published in: Bioresource technology 2012-08, Vol.117, p.172-179
• Main Authors: Yu, Jaecheul, Seon, Jiyun, Park, Younghyun, Cho, Sunja, Lee, Taeho
• Format: Article
• Language: English
• Subjects: Anodic microbial community; Bacteria - metabolism; Biochemical fuel cells; Bioelectric Energy Sources - microbiology; Biological Oxygen Demand Analysis; chemical oxygen demand; Communities; Crack opening displacement; Denaturing Gradient Gel Electrophoresis; Density; Domestic; Effluents; Electricity; Electricity generation; Family Characteristics; Fatty Acids, Volatile - analysis; Loading rate; Low-strength domestic wastewater; microbial communities; microbial fuel cells; Microorganisms; RNA, Ribosomal, 16S - genetics; Submerged-exchangeable microbial fuel cell; Waste Disposal, Fluid; Waste water; wastewater; wastewater treatment; Water Purification - methods
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2012.04.078

► We developed a submerged exchangeable-microbial fuel cell (SE-MFC) system for treating low-strength wastewater. ► We examined the performance of the SE-MFC system using synthetic and domestic wastewater with various COD loading rates. ► As COD loading rates increased, power density increased but COD removal efficiency decreased. ► The newly developed system successfully treated domestic wastewater at 0.32kg-COD/m3/day without additional processing. ► Microbial communities in the two wastewater types were entirely different. A submerged type microbial fuel cell (MFC) system, which consisted of six readily exchangeable air–cathode MFCs, was evaluated for continuous treatment of low-strength domestic wastewater. When supplied with synthetic wastewater (COD 100mg/L), the system showed increasing maximum power densities from 191 to 754mW/m2 as COD loading rates increased (0.20–0.40kg/m3/day). COD removal efficiencies decreased with increased COD loading rates but the effluent COD concentrations met the relevant effluent quality standard (CODMn 20mg/L) at all conditions. The system was then operated with domestic wastewater (c.a. 100mg COD/L) at 0.32 and 0.43kg/m3/day. The system showed much lower power densities (116–149mW/m2) at both loading rates, compared to synthetic wastewater. Anodic microbial communities were completely different when the wastewater type was changed. These results suggest that the newly developed MFC system could be applied to treat low-strength domestic wastewater without requiring any additional organic removal stage.