Substrate concentration dependency of electricity production in microbial fuel cells

Microbial fuel cells (MFCs) provide an opportunity to produce renewable energy from dissolved biodegradable compounds (e.g. organic acids, alcohols, organic wastes) by the special metabolism of the so-called exoelectrogen biomass. The power produced by the MFC depends on the concentration of the organic substrates. Appropriate design of MFC has been developed for determination of the concentration dependency of cell voltage and power, with acetate as energy source. 0.109 mmol/l half saturation constant obtained in this study is one order of magnitude lower than corresponding values of previous studies carried out in different MFCs. Our results show that no considerable power decrease occurs by decreasing the acetate concentration to as low as ~1 mmol/l. This result suggests that efficiency of an appropriately designed MFC may remain high at lower concentrations than previously supposed, leading to new and more effective MFC based technologies both in waste elimination and in renewable energy production.