Electricity Generation Performance Of Microbial Fuel Cell By Using Corn Straw As Anode Substrate

At present,the form of air pollution in our country is harsh.Due to various factors such as industrial emissions,coal combustion and automobile exhaust,the inhalable particulates and pollutants in the atmosphere seriously exceed the standard.Especially in autumn and winter each year,farmers burn a large amount of straw and further worsen the air quality exacerbates air pollution.Microbial fuel cell?MFC?is microbial anode catalysts that convert the chemical energy of organic matter directly into electrical energy.MFC eliminates the need for a combustion step during energy conversion and improves energy conversion efficiency.It not only solves the problem of proper handling and effective utilization of straw,but also has great application prospects.In this experiment,the double chamber microbial fuel cell?MFC?was built with K₃[Fe?CN?₆]as the catholyte.The effect of both the concentration of corn stalk hydrolysis solution and the activated sludge volume on the performance of electricity production of MFC were investigated.Under the experimental conditions,with the increase of activated sludge volume 1.5,3.0,4.5,6.0mL as the anode substrate,the production capacity of MFC increased gradually.The production capacity decreased when the activated sludge was 7.5mL.When the mass concentration of corn stalk hydrolyzate was 0,10,15,20,30,40 g/L,the stable voltage of MFC was 54,157,248,208,170,146mV,respectively.The results showed the best performance of MFC appeared,with its power density is 54.6 mW/m² and the internal resistance is 496?,when the activated sludge volume is 6mL and the corn straw hydrolyzate is 15g/L.Simultaneously,Through the cyclic voltammetry curve?CV?and electrochemical impedance spectroscopy?EIS?test,the electrode process is controlled by the charge transfer and diffusion processes,the reaction process is controlled by electrons transfer.The anode carbon felt?blank CC?was modified by various methods such as HNO₃ acid treatment?HNO₃/CC?,Chitosan modification?Chitosan/CC?and layer-by-layer self-assembly?PDADMAC/?-Fe₂O₃/CC?;the effect of anode modification on the performance of MFC in electricity generation was investigated.The results indicate that with blank CC,HNO₃/CC,Chitosan/CC and PDADMAC/?-Fe₂O₃/CC as the anode materials,the maximum electricity outputs of MFC are 248,315,452 and 522mV,respectively,the maximum power densities are54.6,92.7,203.8 and 248.1 mW/m²,respectively,and the COD removal rates are 82.21%,81.46%,82.53%and 86.44%,respectively.Moreover,PDADMAC/?-Fe₂O₃/CC exhibits the highest redox potential according to the CV curves and minimum polarization resistance?7??as determined by the EIS curves.As a result,the performance of MFC with four anodes follows the order of PDADMAC/?-Fe₂O₃/CC>Chitosan/CC>HNO₃/CC>blank CC.