Based On The Tubular Carbon Film MFC-ANMBR Operation Performance Research

Due to Microbial fuel cell(MFC)use of energy in the sewage to generate electricity,that becoming increasingly popular.However,the poor water quality and the low output of electric power are the technical problems restricting its widespread application.In this study,an MFC-AnMBR was constructed with tubular carbon membrane with both conductivity and filtration.The operation characteristics of tubular carbon membrane electrode in MFC system were studied,the mechanism of the effect of cathode filtration of tubular carbon membrane electrode on MFC operation was elucidated,and the operation effect and pollution status of tubular carbon membrane electrode under different filtration flux in MFC-AnMBR system was investigated.Tubular carbon membrane as the MFC electrode under unfiltered conditions,electricity performance and carbon rod electrode are basically the same,by the specific surface area and catalyst constraints,electricity performance less than the brush electrode and platinum catalyst electrode.When tubular carbon membrane is as a cathode,its filtration behavior influences the operating results of MFC.When oxygen is the cathode oxidant,the flux increased from 0 L/(m2·h)to 100 L/(m2·h),which promoted the operation of MFC significantly,the power density was increased by 358.69 mW/m2(80%)and the internal resistance was reduced by 212.80 ?(42%).This indicates that the cathode filtration behavior can enhance the contact of the electron acceptor with the electrode by accelerating the mass transfer of oxygen to the cathode,thus effectively reducing the system resistance,improving the MFC's electricity production performance.However,when the flux is too high,the electrode reaction kinetics process changes from mass transfer control to electrode reaction control,thus the influence of flux on MFC power generation performance is no longer significant.When the cathode oxidant is potassium ferricyanide,the flux increased from 0 L/(m2 h)to 50 L/(m2 h),which significantly promoted the operation of MFC,but the flux continues to improve operating performance begun to decline significantly.When the filtration flux was 150 L/(m2·h),the specific power density was 429.46 mW/m2(78%)lower than that of the unfiltered system,resistance increased by 725.80 ?(141%).When potassium ferricyanide is used as a cathode oxidant,the trend is the same with oxygen at low flux,however,when the flux is too high,potassium ferricyanide decomposition and Fe2+/Fe3+ hydrolysis to deposit a large amount of solid on the surface of the cathode carbon membrane,but this serious cathode membrane pollution but on the contrary makes the MFC operation effect dropped significantly.When tubular carbon membrane is as an anode,the filtration behavior influences the operating results of MFC-AnMBR.The flux increased from 0 L/O(m2 h)to 30 L/(m2·h)had a significant effect on the start-up time of MFC,shortened by 550 h(63%).This shows that the anode filtrations i accelerates the formation of biofilm on the electrode surface and shorten the startup time.After stable operation of the system,the operation performance is basically the same between the flux is 10 L/(m2·h)and 20 L/(m2 h),which is slightly higher than that of the unfiltered system.However,when the filtration flux was 30 L/(m2·h),the operation performance was obviously decreased,the power density was reduced by 129.56 mW/m2(29%)and the internal resistance was increased by 79.96 ?(16%)compared with the unfiltered system.Indicating that the anodic filtration enhanced electrons in the "substrate-microbial-electrode" microenvironment conductive effect,the filtration behavior increases the geometric area of the carbon membrane electrode,thereby reducing the internal resistance and enhancing the electric power generation performance.However,due to the rate of membrane fouling is accelerated during high-flux,the contact area between the electrode and the microbial is reduced,thereby increasing the internal resistance and reducing the system operation effect.As the filtration flux increases,COD removal efficiency increased significantly,increasing to 92%at 20 L/(m2·h).The different electric fields produced by different filtration fluxes,change the nature of the sludge suspension and slow the membrane fouling.