Anaerobic organic matter degradation in Microbial fuel cell

Several studies have shown that Microbial fuel cell (MFC) converts organic matter of different nature into electrical power. However, the studies are usually focused on electricity production instead of describing the effects of mineralization. In this study the mixed microbial culture isolated from lake sediment sample was tested as an exoelectrogenic and organics degradation agent. The experiments were conducted in the conditions of Microbial Fuel Cell (MFC) designed as a cylindrical anode and cathode chambers, separated by cation-exchange membrane. Both electrodes were made of carbon cloth with circular section. The anode compartment was filled with activated carbon for expanding the anode surface and better electron collection and transport. Together with this, the large surface area provides conditions for formation of a stronger microbial culture through the formation of a biofilm. The MFC was fed with synthetic nutrient medium as an electron donor in the anode chamber and potassium ferricyanide as an electron acceptor in the cathodic reactions. In few sets of experiment a maximal current levels of 0.87 mA (with 100Ω resistor in the electric circuit) were obtained. This electricity generation was accompanied with strong mineralization of the organic medium irrespective of the anaerobic nature of the process. Due to the specific metabolic activity of the isolated microbial culture we established maximal degradation rate of 1.03 kg/m 3 /d. The results demonstrate the potential of the MFC and tested microbial culture in water treatment and energy production. The biggest advantage of this technology is the ability of substrate mineralization in absence of oxygen i.e. without additional aeration of the fluids and related expenses.