Continuous microbial fuel cells convert carbohydrates to electricity.
Microbial fuel cells which are operated in continuous mode are more suitable for practical applications than fed batch ones. Three influent types containing carbohydrates were tested, i.e. a glucose medium, a plant extract and artificial wastewater. The anode reactor compartment yielding the best results was a packed bed reactor containing graphite granules. While in non-mediated batch systems power outputs up to 479 W m(-3) of anode compartment could be attained; in continuous mode the power outputs were limited to 49W m(-3). Cyclic voltammetry was performed to determine the potential of the in-situ synthesized bacterial redox mediators. Addition of mediators with a potential similar to the bacterial potential did not significantly alter the MFC power output, indicating a limited influence of soluble mediators for continuous microbial fuel cells. Maximum coulombic and energy conversion efficiencies were, for the continuous microbial fuel cell operating on plant extract at a loading rate of 1 kg COD m(-3) of anode compartment per day, 50.3% and 26.0% respectively.
Rabaey
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I
Laboratory for Microbial Ecology and Technology, Ghent University, Coupure Links 653, Ghent, Belgium.
Ossieur
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Verhaege
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M
Verstraete
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D031002:Acer / Q000737:chemistry; D000085:Acetates / Q000378:metabolism; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D001674:Bioelectric Energy Sources; D004560:Electricity; D004566:Electrodes; D005947:Glucose / Q000378:metabolism*; D007202:Indicators and Reagents; D007203:Indigo Carmine; D008751:Methylene Blue / Q000031:analogs & derivatives; D010078:Oxazines; D010619:Phenazines; D010936:Plant Extracts / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism*; D014865:Waste Disposal, Fluid / Q000379:methods*
D000085:Acetates; D007202:Indicators and Reagents; D010078:Oxazines; D010619:Phenazines; D010936:Plant Extracts; C035184:new methylene blue; D013395:Sucrose; C014180:resorufin; D007203:Indigo Carmine; D005947:Glucose; D008751:Methylene Blue; C009195:safranine T