Study On The Structure And Application Of Microbial Fuel Cell Based On Aerobic Granular Sludge

Microbial Fuel Cell?MFC?is a device that converts chemical energy in a matrix into electrical energy through the catalytic action of microorganisms.In this study,a dual-cylinder MFC was used and coupled with Aerobic Granular Sludge to construct a microbial fuel cell?MFC-AGS?treatment system based on aerobic granular sludge and applied to the treatment.Landfill leachate,inspect its pollutant removal and electricity production performance,explore the process operating conditions,analyze the functional microbial population structure changes,the research results can provide a theoretical basis and technical support for the practical application of the combined process.The main conclusions of this study are as follows:?1?A microbial fuel cell based on aerobic granular sludge is activated in a batch manner to culture MFC microorganisms.Every 20 h is a cycle,the anode chamber is stirred for 19.5 h,the sediment is drained for 30 min,the drainage ratio is 2:3,the cathode chamber is aerated for 20 h,the precipitation is 3 min,and the drainage is 2:3.At the beginning,the voltage signal transmitted by the system gradually rises,and the maximum voltage reaches 157 mV.After the end of microbial acclimation,the maximum output voltage is about 459 mV,and the high voltage output can be kept stable for a long period of time.After the start of the startup,the fuel cell operates as a continuous feed water.?2?The extended hydraulic retention time?HRT?is beneficial to the transfer of electrons in the anode chamber,thereby enhancing the electrical production performance and the removal effect of pollutants.At HRT 72 h,the removal rates of COD,ammonia nitrogen,total nitrogen and total phosphorus were 93%,86%,63%and 56%,respectively.The external resistor(R_ext)will affect the MFC power generation and pollutant removal effect.The experimental results show that the electron is more easily transferred through the external circuit under the condition of low resistance,and the increased current will bring higher power output and pollution.The material removal performance is improved.?3?By changing the rated voltage of the external solar panel,the external voltage is applied to the MFC production and decontamination performance.The results show that the applied voltage will stimulate the microbial activity at the rated voltage of 2 V,5 V,5 V,5 V solar panels.Under the action of time,the maximum removal rates of COD,NH₃-N,TN and TP were 94%,88.6%,62.6%and 60%,respectively.Changing the illumination time of the solar panel can also affect the performance of the MFC.When the optimal illumination time is 18 h,the maximum voltages of COD,NH₃-N,TN,and TP reach 0.65 V,0.6 V,and 0.72 V,respectively.0.62 V,0.6 V,the maximum power density is 56 mW/m³,50 mW/m³,60 mW/m³,40 mW/m³,37 mW/m³,and the removal rates are 95.6%,86.8%,60%,54.3%,respectively.?4?At the level of the door,Proteobacteria and Actinobacteria are important electrogenic microorganisms for aerobic granular sludge.Firmicutes have an important effect on nitrogen removal in the bacterial horizontal distribution of anaerobic sludge gates.At the genus level,Thauera in aerobic granular sludge is a typical denitrifying bacterium that reduces NO₃^--N to NO₂^--N,and Trichococcus is significantly affected by the external electric field.After the application of voltage,the new Saccharibacteria improves the performance of the MFC system to degrade pollutants.The applied voltage activates the functions of lipid transport and metabolism and thioglycol transport and metabolism in aerobic granular sludge microbial cells.Similarly,the abundance of metabolically related functional genes in the anaerobic sludge functional gene classification is improved under the condition of applied voltage than under no voltage.