RSE - Ricerca sul Sistema Elettrico S.p.A., Environment and Sustainable Development Department, Via Rubattino 54, 20134 Milan, Italy.
Bioelectrochemistry. 2013 Aug;92:6-13. doi: 10.1016/j.bioelechem.2013.01.005. Epub 2013 Feb 8.
The oxygen reduction due to microaerophilic biofilms grown on graphite cathodes (biocathodes) in Single Chamber Microbial Fuel Cells (SCMFCs) is proved and analysed in this paper. Pt-free cathode performances are compared with those of different platinum-loaded cathodes, before and after the biofilm growth. Membraneless SCMFCs were operating in batch-mode, filled with wastewater. A substrate (fuel) of sodium acetate (0.03 M) was periodically added and the experiment lasted more than six months. A maximum of power densities, up to 0.5 W m(-2), were reached when biofilms developed on the electrodes and the cathodic potential decreased (open circuit potential of 50-200 mV vs. SHE). The power output was almost constant with an acetate concentration of 0.01-0.05 M and it fell down when the pH of the media exceeded 9.5, independently of the Pt-free/Pt-loading at the cathodes. Current densities varied in the range of 1-5 Am(-2) (cathode area of 5 cm(2)). Quasi-stationary polarization curves performed with a three-electrode configuration on cathodic and anodic electrodes showed that the anodic overpotential, more than the cathodic one, may limit the current density in the SCMFCs for a long-term operation.
本文证明并分析了单室微生物燃料电池（SCMFC）中石墨阴极（生物阴极）上微需氧生物膜的氧还原作用。在生物膜生长前后，比较了无铂阴极与不同负载铂阴极的性能。无膜 SCMFC 以批处理模式运行，填充废水。周期性地添加基质（燃料）乙酸钠（0.03 M），实验持续了六个多月。当电极上形成生物膜并且阴极电势降低（相对于 SHE 的开路电位为 50-200 mV）时，达到了最大功率密度，最高可达 0.5 W m(-2)。当乙酸盐浓度为 0.01-0.05 M 时，输出功率几乎保持不变，而当介质的 pH 值超过 9.5 时，输出功率会下降，与阴极上是否负载 Pt 无关。电流密度在 1-5 Am(-2)范围内变化（阴极面积为 5 cm(2))。在阴极和阳极上采用三电极配置进行的准稳态极化曲线表明，在 SCMFC 的长期运行中，阳极过电势可能比阴极过电势更限制电流密度。
