Influence of ionic conductivity in bioelectricity production from saline domestic sewage sludge in microbial fuel cells

Bioresour Technol. 2016 Jan:200:845-52. doi: 10.1016/j.biortech.2015.10.101. Epub 2015 Nov 4.

Abstract

This study aimed at manipulating ionic conductivity (EC) to harvest the maximum electrical energy from seawater-based domestic wastewater sewage sludge (SWS), unique to only a few cities, through microbial fuel cell (MFC). SWS has never been investigated as a MFC substrate before, and thus the influence of high in-situ EC on the energy recovery was unknown. In this study, the EC of the SWS was reduced through mixing it with fresh water-based domestic wastewater sewage sludge (FWS) or diluted 50% using deionized water while FWS and SWS were individually served as reference treatments. SWS:FWS mix (1:1) exhibited a maximum Coulombic efficiency of 28.6±0.5% at a COD removal of 59±3% while the peak power density was 20-fold higher than FWS. The improved performance was due to the lower ohmic internal resistance (36.8±4.2Ω) and optimal conductivity (12.8±0.2mScm(-1)). Therefore, dilution with FWS could enhance energy recovery from SWS.

Keywords: Bioelectricity; Ionic conductivity; Microbial fuel cell; Power density; Saline sewage sludge.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bioelectric Energy Sources*
  • Biological Oxygen Demand Analysis
  • Electric Conductivity*
  • Electrolytes / chemistry
  • Hydrogen-Ion Concentration
  • Ions
  • Salinity*
  • Sewage / microbiology*
  • Wastewater / chemistry

Substances

  • Electrolytes
  • Ions
  • Sewage
  • Waste Water