This study developed a new microbial fuel cell (MFC) system (Sponge-MFC), which consisted of a cathodic chamber with an added sponge and two anodic chambers, for low carbon/nitrogen (C/N) wastewater treatment. When operating in the closed-circuit state, the Sponge-MFC(C) demonstrated its superior electrochemical performance compared to the closed-circuit MFC. This superiority took the form of higher coulombic efficiencies, voltage outputs, current densities and power densities. Adding a sponge could reduce the cathode’s charge transfer resistance and solution resistance, and improve its capacitance, thus increasing cathodic reaction rate and power outputs. Simultaneous nitrification denitrification (SND) and bioelectrochemical denitrification processes on the cathode coupled with the sponge’s SND process were responsible for efficient removal of nitrogen from the Sponge-MFC(C). Fluorescent in situ hybridization (FISH) analysis revealed that nitrifying bacteria and highly diversified denitrifying bacteria were distributed at the cathode’s outer layer and inner layer, respectively. Higher phosphorus removal efficiencies (82.06 ± 1.21%) in the Sponge-MFC(C) than that in the MFC(C) (53.97 ± 2.32%) could be ascribed to biological phosphorus removal and precipitation of phosphate salts on the cathode. These results suggested the Sponge-MFC(C) could accomplish better electrochemical behaviors and nutrient removal due to sponge addition when treating wastewater with low C/N ratio.

这项研究开发了一种新的微生物燃料电池（MFC）系统（Sponge-MFC），该系统由一个带有海绵的阴极室和两个阳极室组成，用于低碳/氮（C / N）废水处理。当在闭路状态下运行时，Sponge-MFC（C）表现出比闭路MFC更出色的电化学性能。这种优势表现为更高的库仑效率，电压输出，电流密度和功率密度。添加海绵可以降低阴极的电荷转移电阻和溶液电阻，并提高其电容，从而提高阴极反应速率和功率输出。阴极上同时进行的硝化反硝化（SND）和生物电化学反硝化工艺，再加上海绵的SND工艺，可以有效地从Sponge-MFC（C）中去除氮。荧光原位杂交（FISH）分析表明硝化细菌和高度多样化的反硝化细菌分别分布在阴极的外层和内层。Sponge-MFC（C）中的除磷效率（82.06±1.21％）比MFC（C）中更高的除磷效率（53.97±2.32％）可归因于生物除磷和阴极上磷酸盐的沉淀。这些结果表明，当处理低C / N比的废水时，海绵的加入可以使Sponge-MFC（C）达到更好的电化学行为和营养去除。