The Research Of Electricity Production Performance Of Microbial Fuel Cell With Compound Electricity-Producing Bacteria

Microbial Fuel Cell(MFC),as a new technology,can solve two main problems facing the society today:the recovery and treatment of organic wastewater and the production of new energy.Microbial fuel cell technology has strong application potential.Compared with current water treatment technology,microbial fuel cell technology has many advantages,such as high conversion efficiency,strong biocompatibility,saving aeration cost and less sludge production.Therefore,as a new energy technology without pollution and cleanliness,the research and development of microbial fuel cell will be paid more and more attention.In this paper,a traditional dual-chamber microbial fuel cell system was used to investigate the feasibility of four single strains,Saccharomyces cerevisiae,Escherichia coli,Bacillus subtilis and Pseudomonas aeruginosa as anodic power-producing strains,and their electrochemical activities and mechanism were investigated.Among them,Bacillus subtilis microbial fuel cell has the best power generation performance,the highest output voltage can reach 299 mV,followed by Pseudomonas aeruginosa(229mV),Saccharomyces cerevisiae(188 mV),Escherichia coli(172 mV).At the same time,the performance of microbial fuel cells with different combinations of composite strains was studied,and the optimal composite strains composed of Saccharomyces cerevisiae and Bacillus subtilis were screened out.Its maximum output voltage is 554mV,which is much higher than that of single strain microbial fuel cell.In order to further investigate the practical application scope and adaptability of microbial fuel cell system using composite bacteria as power-producing bacteria,the effects of temperature and the pH of anode on the performance of microbial fuel cell system using composite bacteria were studied.The experimental results show that,the performance of the microbial fuel cell system is greatly affected by the pH of anode.The maximum output power is 127 mW/m~2 under acidic conditions,which is more than4 times that under alkali neutral conditions,and the maximum output voltage is 592mV.Temperature has no great influence on this complex strain system.The average output voltage and average output power of the system do not change much at the ambient temperature of 20?-35?.The optimum operating temperature is 30?-35?.This also shows that the two microbial complex bacteria systems we constructed have strong environmental adaptability and stability.And take the complex bacteria as the the microbial fuel cell electrifying bacteria has certain feasibility and advantages.At the same time,the electrochemical properties and biofilm morphology of the complex bacteria and individual strains were identified and analyzed by cyclic Scanning Voltammetry(CV) and scanning electron microscopy(SEM),polarization curve and power density curve.The results showed that the two microbial complexes constructed in this experiment had a strong synergistic effect.Saccharomyces cerevisiae can use riboflavin produced by Bacillus subtilis as a medium to transfer electrons and reduce the internal resistance of microbial fuel cells.At the same time,Saccharomyces cerevisiae can decompose macromolecule nutrients through respiration and supply them to Bacillus subtilis,providing carbon source and electronic donor.