Numerical Simulation For Anode Chamber Reactions Of Continuous Flow MFC

Microbial fuel cells(MFCs)is a kind of green energy technology that can make use of waste water and waste product electricity,and received widespread attention by researchers in recent years.Ordinary MFC is composed by cathode and anode chamber,reactions in anode chamber involves electrochemical and biochemistry and a lot of subjects.Research only from the perspective of macro cannot fully expound the operation mechanism of anode department.This study adopts numerical simulation to study the operation laws in anode chamber,established a mathematical model including soluble chemical substrates,the non-electric production microorganisms,the electric production microorganisms on anode surface and added mediator of MFC that run in continuous flow.By simulation electricity production?COD removal and mass transfer processes under different operating conditions,discuss the operation laws in the anode chamber.In further explain the operation mechanism of MFC.By simulation of open circuit voltage,COD removal,biomass and power density curves under different organic loading conditions,discuss the influence of organic load on electricity generation and decontamination performance of MFC.The results show that,with the increasing of organic load,the open circuit voltage first increases,then fall and get stable at last;COD removal presents a downward trend after the first rise and achieve a maximum 89.1%at the organic load of 200mg/L;In the analog domain,the greater the organic load is,the shorter time it takes for micro-organisms to achieve the rapid growth,the greater of the maximum power density is,but the power density at the maximum organic load rapidly decay after reach the maximum,electricity generation performance decreased.By simulation of open circuit voltage,COD removal and power density curves under different HRT conditions,discuss the influence of HRT on electricity generation and decontamination performance of MFC.The results show that with the increasing of HRT,the open circuit voltage of MFC first increase then decrease;COD removal first increase and then turn to stable,the maximum power density presents an increasing trend.Furthermore,compare the changes of substrate removal and the polarization and power density curve under different initial electric production biomass.Result shows that the more the initial electric production biomass,the better effect of substrate degradation,the higher of maximum power density is.By simulation of current,COD removal and power density curves under different initial non-electric production biomass,discuss the influence of competition between microbial populations on MFC performance.The results show that the more the initial non-electric production biomass is,the better effect of substrate removal is,but electricity generation performance get worse.The coexistence of various groups of microorganisms can help to improve the stain removal performance of MFC,but also limit power production of MFC.Anode area and external resistance will affect the electricity generation and mass transfer resistance conditions.The bigger the anode area is,the stronger the MFC electricity generation performance is,the greater the mass transfer process is affected by spatial factors;the greater the external resistance,the poorer the MFC electricity generation performance is,the smaller the mass transfer process is affected by space factors.Compare the changes of charge and current under different standard redox potential situations.The results show that within a certain range,the greater the standard redox potential is,the stronger of MFC electricity generation performance is.By simulation,compare the current under different initial mediator concentrations.The results indicate that in a certain range,the performance of electricity production is improved with the increasing of initial mediator concentrations,but high initial concentrations of mediator will make the system in "oxidative" state,which have a negative effect on energy production of MFC.