直接微生物燃料电池的构建及初步研究

Construction and Preliminary Studies on the Direct Microbial Fuel Cell

利用Geobactermetallireducens能够以Fe(OH)3固体作电子受体进行呼吸的特性,用其构建直接微生物燃料电池,初步考察了产电情况和产电原理.实验证明,Geobactermetallireducens直接微生物燃料电池的电能产出主要依赖于吸附在电极上的细菌.燃料醋酸钠可以完全氧化至CO2,反应结束后其浓度低于检测下限(<10μmol/L).电子回收率达80%,电流密度达704.4mA/m2.

The mediators added in indirect microbial fuel cells are often toxic, unstable and costly. Direct microbial fuel cells do not need mediators during oxidation of carbohydrate or organic acids, overcoming the above problems, so it can be used in bioremediation and treatment of waste water. In the present work, Geobacter metallireducens, a dissimilatory ferric reducing microorganism that can use Fe（OH）3 as the electron acceptor, was used to construct the direct microbial fuel cell. Geobacter metallireducens was inoculated into chambers in which a graphite electrode served as the sole electron acceptor and acetate was the electron donor. Electricity production and mechanism were preliminarily studied. The direct microbial fuel cell was successfully constructed. It was proved that microbial electricity production was mainly due to the cells attached to the electrode. Electrode-attached cells completely oxidized acetate to the levels below detection limit （〈10 μmol/L）. The electron recovery was 80%, and current density was up to 704.4 mA/m^2.