The Research About Operational Factors On The Mediatorless Microbial Fuel Cell

With the development of energy shortage, it has become a common sense to develop new types of clean energy and adjust energy structure. Microbial fuel cell(MFC)is a new type which generates electricity by using biomass and microorganism.A two-chambered MFC without electron mediator has been designed in this study, in which porous carbon paper is used as the anode material and some electrode material with capability of electricity catalysis is used as the cathode. Sediments of Songhua River is used as initial microorganism and inoculating quality is 60mL. At the stage of start-up, generation electricity in fed-batch is used to domesticate bacterium. Acetic is used as carbon source and concentration is 800mg/L. After cultivating microbe 60 days in this system, maximal value of voltage is 207mV and quality of microorganism increase to 3 times. Then the step of start-up has been finished. Granule active carbon is put in this system to improve sludge sedimentation. When voltage is stable at 170mV, the system is operated in a continuous flow.The COD concentration of influent is kept at 600mg/L and hydraulic retention time maintains at 30h.By changing operational parameters, the variational trend of voltage and COD removal efficiency were observed, and then analyze the rules of electricity generation capability of system. Parameters includes: electrode material of the cathode, electrode area of the anode, pH and ionic Strength. Among these Parameters, maximal voltage has been increased from 184mV to 448mV, and coulombic efficiency has been increased six times. COD removal efficiency is stable at 75%.In this study, it is found that cathode material, pH, ionic intensity in the anode chamber and the electrode space are the main factors on the electricity generation, and it also demonstrate that suspended sludge play the most important part in COD removal and have nothing to do with electricity generation. Electrochemically active microorganisms are obtained in this study. By using of scan electron microscope, in the anode surface, the adsorptive and suspended appearance of microorganism have been observed, which provides...