Fe(Ⅲ)-EDTA作为阴极电子穿梭体的微生物燃料电池持续产电机制  

Sustainable Electricity Generation in Microbial Fuel Cells Using Fe(Ⅲ)-EDTA as Cathodic Electron Shuttle

作　　者：邓丽芳[1,2,3] 周顺桂[2] 张锦涛[2] 庄莉[2] 卢娜[2] 张礼霞[2] 

机构地区：[1]中国科学院广州地球化学研究所,广州510640 [2]广东省生态环境与土壤研究所,广州510650 [3]中国科学院研究生院,北京100049

出　　处：《环境科学》2009年第7期2142-2147,共6页Environmental Science

基　　金：国家自然科学基金项目(40601043;20777013);广东省自然科学基金项目(07006759);广东省科学科技创新引导项目(CX2007)

摘　　要：阴极氧还原反应(ORR)是影响微生物燃料电池(microbial fuel cell,MFC)性能的重要因素.采用双室MFC以Fe(Ⅲ)-EDTA为阴极液进行持续产电试验.结果表明,添加Fe(Ⅲ)-EDTA作为阴极液可显著加速氧还原反应速率,降低内阻,提高输出电压与功率.当阴极液中存在20.0mmol/L的Fe(Ⅲ)-EDTA时,电池内阻仅为300Ω,比对照降低了900Ω,其输出电压(1000Ω下)与功率密度可维持在200.1mV、16.0mW/m2左右,比不加的对照分别提高73.2%、70.1%.Fe(Ⅲ)-EDTA氧化再生与持续产电试验表明,Fe(Ⅲ)-EDTA可通过曝气氧化再生、循环利用,即Fe(Ⅲ)-EDTA可作为阴极电子穿梭体加速电子至氧气的传递.Fe(Ⅲ)-EDTA首先接受阴极电子被还原成Fe(Ⅱ)-EDTA,在阴极室充分曝气条件下,Fe(Ⅱ)-EDTA将电子传递给O2同时被氧化再生成Fe(Ⅲ)-EDTA,从而完成电子从电极传递到氧气的穿梭过程,MFC得以长期稳定运行.进一步优化试验显示,Fe(Ⅲ)-EDTA作为阴极电子穿梭体强化MFC产电的适宜条件为:浓度20.0mmol/L、pH=5.0左右.在此条件下MFC的最大功率密度达100.9mW/m2.The rate of oxygen reduction reaetion （ORR） at the cathode is a major factor a-fleeting the performance of the microbial fuel cells （MFC）. Results showed that when using Fe（ Ⅲ）-EDTA solution as catholyte, the ORR rate was significantly increased and the internal resistance was reduced, consequently leading to an inerease in power output. With a concentration of Fe（ Ⅲ）-EDTA at 20.0 rmnol/L in the catholyte, the MFC produced the voltage and power density at approximate 200.1 mV and 16.0 mW/m^2 , respectively, whieh was increased by 73.2% and 70.1% contrary to the MFC without the presence of Fe（Ⅲ）-EDTA. The further experiment suggested that Fe（m ）-EDTA functioned as electron shuttle to accelerate electron transfer. Fe（ Ⅲ）-EDTA received eleetron and got reduced to Fe （ Ⅱ ）-EDTA, which further provided electrons to oxygen and got reoxidized at the same time. Therefore Fe（ Ⅱ ）-EDTA can act as recyclable electron shuttles between cathode electrode and oxygen. The optimum condition in the case of using Fe（ Ⅲ ）-EDTA as cathode electron shuttles was tested to be Fe（ Ⅲ ）- EDTA concentration at 20.0 mmol/L and pH at 5.0,which allowed MFC produced the maximum power density of 100.9 mW/m^2 .

关 键 词：微生物燃料电池 电子穿梭体 Fe(Ⅲ)-EDTA 氧化再生 KLEBSIELLA PNEUMONIAE L17 

分 类 号：X382[环境科学与工程—环境工程]