Journal of Chemical Technology and Biotechnology, Vol.89, No.11, 1727-1732, 2014
Obtaining microbial communities with exoelectrogenic activity from anaerobic sludge using a simplified procedure
BACKGROUND: The microbial fuel cell (MFC) technology transforms the chemical energy present in substrates into electricity. Starting-up these systems, i.e. enriching the anodic community in exoelectrogenic bacteria, is a lengthy process or requires expensive equipment. RESULTS: An easy and low-cost procedure based on a sediment MFC was developed to select microbial communities with exoelectrogenic activity from the anaerobic sludge of a waste water treatment plant (WWTP). The configuration was based on a simple vessel working as a single chamber MFC with a cathode of stainless steel wool in the liquid surface and a submerged graphite fibre brush as anode. In 30 days of operation, a biofilm with remarkable exoelectrogenic activity was grown on the anode of the MFC. This graphite fibre brush anode was able to supply 0.9 W m(-2) when working in an air-cathode MFC (AC-MFC) for 45 days. CONCLUSION: The procedure presented was demonstrated to be a successful, low-cost and low-maintenance procedure to obtain exoelectrogenic activity and had performances comparable with other more costly and complex inoculation procedures. The Sed-MFC does not require a potentiostat, external aeration, stirring, membranes or an enriched inoculum in the exoelectrogenic biomass. (C) 2013 Society of Chemical Industry
Keywords:anaerobic sludge;exoelectrogenic bacteria;microbial fuel cell (MFC);sediment MFC;stainless steel cathode