阳极电势对MFC中产电的影响

在微生物燃料电池(MFC)中,与微生物接触的阳极自身电场环境就可能会对产电菌的生长和代谢产生重要影响,进而影响到MFC产电效能.为探索阳极电势的作用,本研究在微生物燃料电池的阳极室中通过设置附加电路来人为改变阳极电势,考察了阳极电势对MFC产电的影响.结果表明,当阳极电势在-380 mV降低到0 mV过程中,MFC输出功率提高.当阳极电势小于200 mV时,COD去除效率在60%~73%之间变化不大.较低或较高的阳极电势均可增加电池的库伦效率.阳极电势处于-380 mV到0 mV下,厌氧微生物主要以丙酸型发酵为主,产生大量乙酸;COD的分解和利用是分阶段进行的.不同阳极电势下MFC内阻变化主要受浓差内阻影响.阳极电势为-200 mV时欧姆内阻最低,但电化学活性较高.

Effects of anode potential on electricity generation of microbial fuel cell

In the microbial fuel cell (MFC), electric field of anode attached by microbes may have an important impact on growth and metabolism of the electricity production microbes and electricity production ensured. In order to explore the effect of anodic potential, the effect of anode potential on electricity production of the MFC was investigated in this study by setting an additional circuit to the anode. The results show that output power density of the MFC increased when the anode potential decreased from -380 mV to 0 mV. COD removal efficiency varied between 60% and 73% (except the anode potential of 200 mV). Decreasing or increasing anode potential could raise coulomb efficiency. When anodic potential was controlled at -380 mV to 0 mV, the fermentation type was propanoic acid pathway, and anaerobic microorganisms produced a large amount of acetic acid. Concentration resistance mainly affected the change of MFC resistance under the different anode potential. When the anode potential was -200 mV, ohmic resistance was minimum, but electrochemical activity was higher.