Microbial Fuel Cell Technology Research And The Structure Optimization Design Of The System

Microbial fuel cell （MFC） technology is a new method for energy generation,because it can produce electricity by using bacteria during the organic degradation process.It has attracting more and more researchers’ attention all over the world as its advantageon power generation, organic degradation and cost decreasing. However, more and moreefforts could be needed to apply to industrial application in the future, especial forenhancing the power performance. In this study a series of investigation on proving thepower performance of MFC could be executed and addressed as following.Firstly, the carbon nanotube （CNT） planted on the alloy substrate is used as theelectrode in MFC for degradating the dairy wastewater and energy production. Resultsshow that the maximum power density of CNT-based electrode MFC produced is2.28W/m², the limiting current density is11.95A/m², and the COD degradation is24.52%after10days, which is as twice times as the performance of alloy electrode without CNT.The reason for the superior performance based on the case of with CNT could be resultedfrom the special3D structure pattern of CNT which can make bacterial easy to adhesionand reproduction. At the same time, the activation and concentration polarization will bedecreased. In addition, the technology of CNT also affects on the power generation andneed more efforts to improve the preparation technology of CNT.Secondly, an optimal structure design of MFC conducted by different kinds of flowchannel, convergent, diverging, circle and square flow type in the chamber and confirmedby both simulation analysis and experiment. The mixing effiency of diverging channelperforms best in the simulation at Re=60; while in the experiment the convergent channelperforms best, both the power performance and the COD degradation, and followingdiverging, square and circle. The difference between simulation and experiment showsthat the MFC is much more complicated than the simple engineering model, but theengineering thinking can be applied to improving the performance of MFC.Finally, much research on the cathode was made but rare study involved with the utilization of cathode was noted. In this study a bio-electro-Fenton technology could beapplied. Here, carbon felt is used as the electrode material. With FeSO₄·6H₂O added intothe cathode, the oil wastewater is degredated49.4%, which is far better than that of thecontrol group. Through the longtime discharging, the bio-electro-Fenton system canimprove the power performance of MFC. This technology can be further used in practicalindustry wastewater treatment for diverse development of treating wastewater.In this study, all of the investigations addressed have been proven for improving thepower performance of MFC, both the power generation and COD degradation. These findswould be useful to improve the power performance of MFC in the future.