The performance of microbial anodes in municipal wastewater: Pre-grown multispecies biofilm vs. natural inocula

Bioresour Technol. 2016 Dec;221:165-171. doi: 10.1016/j.biortech.2016.09.004. Epub 2016 Sep 4.

Abstract

In this study, different inoculation strategies for continuously operated microbial anodes are analyzed and compared. After 20daysof operation with municipal wastewater anodes pre-incubated with a biofilm of the exoelectrogenic species Geobacter and Shewanella showed current densities of (65±8) μA/cm2. This is comparable to the current densities of non-inoculated anodes and anodes inoculated with sewage sludge. Analysis of the barcoded pre-grown multispecies biofilms reveal that 99% of the original biofilm was detached after 20daysof operation with municipal wastewater. This is in contrast to previous experiments where a pre-grown biofilm of exoelectrogens was operated in batch mode. To implement pre-grown biofilms in continuous systems it will thus be necessary to reveal a window of process parameters in which typical exoelectrogenic microorganisms including model organisms can be kept and/or enriched on anodes.

Keywords: Anode; Geobacter; Inoculation; Microbial community; Microbial fuel cell; Pregrown biofilm; Shewanella; Wastewater.

MeSH terms

  • Bioelectric Energy Sources / microbiology*
  • Biofilms
  • Electrodes / microbiology*
  • Geobacter / physiology*
  • Sewage
  • Shewanella / physiology*
  • Waste Disposal, Fluid / instrumentation*
  • Waste Disposal, Fluid / methods
  • Waste Water

Substances

  • Sewage
  • Waste Water