底物对微生物燃料电池产电性能的影响

在自行构建的"H"型双室微生物燃料电池(MFC)中,以湖南省吉首市大田湾污水处理厂曝气池中的污泥为接种污泥,以可溶性淀粉和白糊精为底物,考察不同底物及其质量浓度对MFC获得稳定开路电压所需时间、启动时间、电动势、内阻及功率密度等性能的影响.实验结果显示,在同样的条件下,以白糊精为底物的MFC启动快、内阻小、功率密度较小,而以可溶性为底物的MFC启动慢、内阻大、功率密度大;底物质量浓度低于6g/L时,以可溶性淀粉为底物的MFC达到稳定开路电压的时间随质量浓度增大而增加,底物质量浓度低于8g/L时,以白糊精为底物的MFC达到稳定开路电压的时间随质量浓度增大而增加.由于底物抑制效应,质量浓度较高时,随着底物质量浓度的增加.MFC达到稳定开路电压所需的时间反而减少.

Effects of Substrate on the Electricity Generation Characteristics of Microbial Fuel Cell

A reaction equipment of microbial fuel cell (MFC) with “H” structure was designed and fabricated.The sludge collected from the aeration tan in Datianwan Sewage Treatment Plant in Jishou was used to inoculate electricigens.The effects of substrate species and concentration on the electricity generation of MFC in view of start-up time,time for obtaining stable open circuit voltage,electromotive force,internal resistance and power density were investigated.Experimental results showed that the substrate species and concentration greatly influenced the electricity generation of MFC probably due to their difference in structure.It was found that the white dextrin-fed MFC could be started up in shorter time with smaller internal resistance,smaller electromotive force and smaller power density.Under the same conditions,the soluble starch-fed MFC had larger electromotive force,larger power density,bigger internal resistance and longer time to be started-up.The results also indicated that an increase in the substrate concentration increased the time for reaching constant OCV at low concentration of 2~6 g/L for soluble starch and 2~8 g/L for white dextrin.While an opposite trend was observed at high concentration of 8~20 g/L for soluble starch and 10~20 g/L for white dextrin attributed to the substrate inhibition effect.