Electricity generation from wastewaters with starch as carbon source using a mediatorless microbial fuel cell

Microbial fuel cells represent a new method for producing electricity from the oxidation of organic matter. A mediatorless microbial fuel cell was developed using Escherichia coli as the active bacterial component with synthetic wastewater of potato extract as the energy source. The two-chamber fuel cell, with a relation of volume between anode and cathode chamber of 8:1, was operated in batch mode. The response was similar to that obtained when glucose was used as the carbon source. The performance characteristics of the fuel cell were evaluated with two different anode and cathode shapes, platinised titanium strip or mesh; the highest maximum power density (502 mW m−2) was achieved in the microbial fuel cell with mesh electrodes. In addition to electricity generation, the MFC exhibited efficient treatment of wastewater so that significant reduction of initial oxygen demand of wastewater by 61% was observed. These results demonstrate that potato starch can be used for power generation in a mediatorless microbial fuel cell with high removal efficiency of chemical oxygen demand.

► Electricity was harvested from a mediatorless microbial fuel cell with E. coli.
► Electricity from potato starch was generated at a maximum power density of 502 mW m−2.
► A similar output was obtained when glucose was used as the carbon source.
► Chemical Oxygen Demand removal of the MFC reached 60.8±5.2%.
► Photographs showing microbial communities attached on anode surface were taken.