• activated sludge;
  • biocathode;
  • energy recovery;
  • microbial fuel cell (MFC);
  • sequencing batch reactor (SBR);
  • upgrade


In the research and application of microbial fuel cell (MFC), how to incorporate MFCs into current wastewater infrastructure is an importance issue. Here, we report a novel strategy of integrating an MFC into a sequencing batch reactor (SBR) to test the energy production and the chemical oxygen demand (COD) removal. The membrane-less biocathode MFC is integrated with the SBR to recover energy from the aeration in the form of electricity and thus reduce the SBR operation costs. In a lab-scale integrated SBR-MFC system, the maximum power production of the MFC was 2.34 W/m3 for one typical cycle and the current density reached up to 14 A/m3. As a result, the MFC contributed to the 18.7% COD consumption of the integrated system and also recovered energy from the aeration tank with a volume fraction of only 12% of the SBR. Our strategy provides a feasible and effective energy-saving and -recovering solution to upgrade the existing activated sludge processes. Biotechnol. Bioeng. 2011; 108:1260–1267. © 2011 Wiley Periodicals, Inc.