Characterization of design factors affecting power output in a microbial fuel cell

Several advances in the design of the fuel cells that could make these processes economical for treating waste organic matter and generating electricity at the same time is presented. The use of ferricyanide ion in the cathode compartment can increase power output of microbial fuel cell by 1.5 to 1.8 times compared to that achieved with dissolved oxygen (DO). The concentration of DO in the cathode chamber was also a factor in power generation, with the power levels exhibiting Monod like kinetics with a DO half saturation constant of K_DO = 1.74 mg-O₂/L. Power output was a function of sizes of the cathode, anode electrode and proton permeable membrane. The KCl concentrations (∼ 0.3 M) in the anode or cathode chamber increased the power output by ∼ 56%. KCl concentrations above 0.4 M in the anode chamber decreased the power output resulting from inhibition of microorganisms by the higher concentrations of KCl. This is an abstract of a paper presented at the 228th ACS National Meeting (Philadelphia, PA 8/22-26/2004).