Study On Biomass Derived Carbon Based Anodes In Microbial Fuel Cells Of Wastewater Treatment And Power Generation

With the rapid development of economy and the improvement of people’s living standards,the proplems of global energy shortage and water pollution are becoming more and more serious.It is urgent to explore clean and efficient energy and wastewater treatment technologies.Microbial fuel cells(MFCs)is a energy technology that can treat wastewater and generate electric energy.It has incomparable advantages over traditional wastewater treatment technologies.However,its low power output and high cost still hinder its application.To solve the above problems,this study prepared high-performance and low-cost electrodes by developing cheap and easily available anode materials,optimizing and designing material characteristics,and realized the high power output and organic matter removal of MFCs.The specific conclusions are as follows:(1)Carbon nanoparticles(HPCN)and carbon nanoparticles composite polyaniline(HPCN-PANI)with regular and uniform spherical structure were prepared from tannic acid by template free method.HPCN-PANI has the characteristics of uniform nano size,microporous porous structure and heteroatom C,N,P,S and Co doping,The ohmic resistance(1.526Ω)and charge transfer internal resistance(4.523Ω)of HPCN-PANI modified carbon cloth anode(HPCN-PANI/CC)are much lower than CC(7.443Ωand 24.473Ω),PANI/CC(6.356Ωand 11.236Ω)and HPCN/CC(2.225Ωand 5.891Ω).The preparation cost of the anode is about 45.66$/m~3,which is significantly lower than that of most nano carbon based anodes at present.(2)The effects of HPCN-PANI material on the properties of MFCs were discussed.The output voltage of MFCs equipped with HPCN-PANI/CC is 0.523V and the power density is 2.22 W/m~2,which is higher than the single chamber MFCs currently reported.The removal rate of chemical oxygen demand(COD)was 94.33%,higher than CC(88.34%),PANI/CC(90.12%)and HPCN/CC(92.15%).The charge transfer resistance(1.191Ω)is significantly lower than CC(15.722Ω),PANI/CC(4.536Ω)and HPCN/CC(2.976Ω),and is lower than the anode reported so far.The above shows that HPCN-PANI/CC is an efficient anode material.(3)In exploring the mechanism of HPCN-PANI material improving the performance of MFCs,it is found that HPCN-PANI integrates the advantages of HPCN functional microbial enrichment and PANI microbial adsorption,strengthens the gene pathway related to electron transfer,and significantly enhances the direct electron transfer process between c-type cytochromes(c-Cyts)and the electrode.(4)Sludge carbon(SC)was prepared from surplus aerobic activated sludge.The effects of SC on the performance of MFCs were studied.The research shows that the output voltage of MFC equipped with 1000℃carbonized SC anode(SC1000/CC)is 0.501V,the power density is 2.16 W/m~2,and the COD removal rate is 97.63%,which are higher than other SC anodes in this study.The preparation cost of SC1000/CC anode is about 32.11$/m~3,which is lower than that of most anodes studied at present.(5)In the process of exploring the mechanism of SC anode material improving the performance of MFCs,it is found that SC can change the flora structure of Archaea and bacteria,and there may be electron shuttle electron transfer between Archaea and its bacterial partners,induce bacteria to produce extracellular polymer substance(EPS),regulate the microenvironment of biofilm,and significantly increase the content of protein,polysaccharide and c-Cyts in EPS,Further affect the power production performance of the reactor.