School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China; State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China.
School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China; State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China; Shandong Provincial Engineering Center on Environmental Science and Technology, Jinan, 250061, China.
Water Res. 2019 Nov 1;164:114955. doi: 10.1016/j.watres.2019.114955. Epub 2019 Aug 6.
Photosynthetic microbial fuel cells (PMFCs) allow renewable energy production from wastewater. However, system scale-up is still a major challenge hindering the use of PMFCs for practical applications. Herein, a PMFC stack, which consisted of multiple anodic chambers installed in an algal raceway pond (ARP), was established to recovery energy from anaerobically digested effluent with the assistance of a prototypical capacitor circuit. The highest voltage output of the stack reached 1.4 V with four PMFC units and four capacitors. The system can produce stable voltages through controlling charging and discharging frequencies and the voltage output remained stable around 0.60 V when the time interval decreased to 2 s. During long-term operation, the highest power density of the stack with capacitors reached 2.34 W/m, which was 77% higher than that without capacitors (1.32 W/m). About 98% of the ammonium in the anolyte was removed, resulting from the ammonium migration effect. The dynamics of bacterial community compositions were not greatly influenced by the capacitor circuit, and the stack with capacitors had a more stable bacterial community compared to the stack without capacitors. The variations in bacterial community composition following power density changes indicated that members of the Clostridia and Betaproteobacteria were related to power generation. Bacteria affiliated to Bacteroidetes were inhibited when power density was high, though their numbers were enriched at the end of the process. This study promotes a practical method for developing the PMFC technology into real-world applications, and furthermore reveals the main bacteria that play vital roles in power generation by analysing the anodic bacterial community during the whole process.
光合微生物燃料电池（PMFC）可利用废水产生可再生能源。然而，系统规模的扩大仍然是阻碍 PMFC 实际应用的主要挑战。在此，建立了一个由多个安装在藻类跑道池塘（ARP）中的阳极室组成的 PMFC 堆栈，该堆栈在原型电容器电路的辅助下，从厌氧消化废水中回收能量。该堆栈的最高电压输出达到 1.4 V，使用了四个 PMFC 单元和四个电容器。通过控制充电和放电频率，该系统可以产生稳定的电压，当时间间隔减小到 2 s 时，电压输出稳定在 0.60 V 左右。在长期运行中，带有电容器的堆栈的最高功率密度达到 2.34 W/m，比没有电容器时（1.32 W/m）高 77%。由于氨的迁移效应，阳极液中约 98%的铵被去除。电容器电路对细菌群落组成的动态影响不大，并且与没有电容器的堆栈相比，带有电容器的堆栈具有更稳定的细菌群落。随着功率密度变化的细菌群落组成的变化表明，梭菌和β变形菌的成员与发电有关。当功率密度较高时，拟杆菌门的细菌受到抑制，尽管它们在过程结束时数量增加。本研究为将 PMFC 技术开发为实际应用提供了一种实用方法，并通过分析整个过程中的阳极细菌群落，揭示了在发电过程中起重要作用的主要细菌。
