Research On Performance Of Microbial Fuel Cell

With the problems of environment and energy getting worse increasingly. It isvery important to looking for an environmental and low-carbon way to slow downthe energy consumption and reduce the environment pollution. Microbial fuel cell(MFCs) technology is kind of environmental, it not only can reuse the wastes, alsocan produce new sources of energy. Because of the existence of microorganisms,MFCs almost can use all of the organic matters, as long as the correspondingmicroorganisms are chosen. MFCs can produce energy and deal with the environmentpollution at the same time, It has a very good prospects as a kind of new productiontechnology.This paper chose two different kinds of microorganisms: elentricigen-Shewanellamarisflavi EP1and hydrogen-producing microbes-Klebsiella ocytoca HP1, testing theperformance of them by the MFCs, results are sa follows:(1) What we can know is the optimum condition for Shewanella marisflavi EP1producing electrity were:25℃~35℃; ionic strength4%; pH7. Under the conditionof room temperature, tested the properties of Shewanella marisflavi EP1by changingthe size of the external resistance. Then, voltage as ordinate,current as abscissa, drawthe polarization curve, the straight line equation is y=-925.5x+442.0(R2=0.8748),the resistance of MFC is925.5Ω.(2) We can know the optimum condition of the decoloration of Shewanellamarisflavi EP1were:35℃; ionic strength4%; pH7; yeast as the nitrogen soure;sucrose as the carbon source. The experimental results also indicated that:(1) Withthe increase of concentration of the organic nitrogen source will promote thedecolorizing reaction;(2) With the increase of concentration of inorganic nitrogensource, the growth of microbes will be suppressed, the decolorization rate will decline;(3) With the increase of the initial concentration of dye, the decoloraztion rate willdecline.(3) Through testing the performance of the decoloring and electricity production,we can know:(1) The reaction of decoloring and electricity production are existed atthe same time，the point is thedecolorizing reaction will be delayed by electricityproduction reaction, the reason is the electrons which producted by microbesdecomposed oeganic matters are used to produce electricity firstly, the rest ofelectrons can be used to decoloring;(2) The reaction of decolorizing and electricity production also can promote each other.(4) We can know the optimum condition of the hydrogen production rate ofKlebsiella oxytoca HP1were:37℃; pH8; yeast as the nitrogen soure; glucose as thecarbon source.immobilized matrrial is sodium alginate. It turned out that:(1) With thetemperature increasing, the enzyme’s activity will be enhanced,what you should notehere is that the enzyme will lost its activity if the temperature is too high,and thehydrogen production rate will decline;(2) With the increase of the concentration ofcarbon source, the hydrogen production rate will be increased, It is worth mentioningthat a high concentration of carbon source will increase the osmotic pressure andcause the hydrogen production rate declines.(5) Klebsiella oxytoca HP1do not have the performance of elevtricity production,the experimental resultes show that: increasing the concentration od hydrogen ionsbetween two chanmbers by using the membrabe technology can output voltage, theoutput voltage is220mV, hydrogen production is0.90L/L.