基质浓度·电极距离·离子强度对MFC影响的研究

Influence of Substrate Concentration,Electrode Space and Ionic Strength on Microbial Fuel Cell

以宜兰酒厂废水处理厂的污泥为菌种来源,构建单槽无膜无介体空气阴极型微生物燃料电池(Microbial Fuel Cell,MFC),通过添加不同浓度的基质、改变阳极与阴极距离及添加不同浓度的NaCl,分别考察了基质浓度、电极距离、离子强度对MFC性能的影响。研究结果表明,伴随基质COD浓度的增加(从300 mg/L增到1 000 mg/L),库仑效率降低50%,但产电维持时间延长,COD去除率最高达92%;在一定电极距离内(18 cm到9 cm),伴随电极距离的减小,系统内阻减小,产电提高,最大功率密度从39.6 mW/m2增到73.2 mW/m2;当电极距离过短(6 cm)时,产电反而降低;当NaCl浓度为160 mmol/L时有最大功率密度,但是如果盐类浓度过强,会影响阳极生物膜微生物的活性从而降低产电。

Activated sludge was taken from wine-bearing wastewater treatment plant of I-Lan Distillery,and membrane-less and mediator-less air-cathode microbial fuel cells（MFC）were constructed.Influence of substrate concentration,electrode space and ionic strength on the performance of MFC was studied.Results indicated that the coulombic efficiency（CE）decreased by 50% with the substrate concentration increased from 300 COD mg/L to 1 000 COD mg/L,but longer period of time to maintain stable power generation was observed at higher initial glucose concentration,with the maximum COD removal efficiency of 92%.At certain electrode space from 18 cm to 9 cm,power was generated higher for reducing internal resistance,and the maximum power density increased from 39.6 mW/m^2 to 73.2 mW/m^2,however the electricity dropped with the extremely shorter distance of 6cm.The best power density was achieved at NaCl concentration of 160 mmol/L,when the salt concentration was much higher,the performance of MFC would get lower as it limited the activity of microorganism attached on the anode biofilm.