College of Urban Construction, Nanjing Tech University, Nanjing, People's Republic of China.
Environ Sci Pollut Res Int. 2023 May;30(23):63620-63630. doi: 10.1007/s11356-023-26488-2. Epub 2023 Apr 13.
Constructed wetland-microbial fuel cell (CW-MFC) has attracted much attention because of its dual functions of wastewater treatment and energy recovery. However, its performance in treating high-concentration wastewater is degraded by the decreased dissolved oxygen at the cathode and insufficient electron acceptors. In this study, two CW-MFC systems with cathodic aeration were connected in series to investigate the effects of aeration rate and hydraulic retention time (HRT) on the removal of pollutants and the performance of electricity production in high-concentration wastewater. Results showed that aeration enhanced NH-N and TP removal by 45.0-49.8% and 11.5-18.0%, compared with the unaerated condition, respectively. Meanwhile, no significant change regarding COD removal was observed. Aeration enhances the output voltage and power density of the system, especially the first stage CW-MFC, which improved the power production performance by 1 to 2 orders-of-magnitude. Increasing HRT improves the system's pollutant treatment efficiency and power generation performance for high-concentration wastewater. Still, the extension of HRT to 2 days will not contribute much to improving the removal efficiency. Under optimized conditions, the maximum total removal rates of COD, NH-N, and TP for the two-stage tandem CW-MFC system were 99.3 ± 0.2%, 92.4 ± 1.6%, and 79.5 ± 3.4%, respectively. Meanwhile, the maximum output voltage and maximum power density of the first-stage CW-MFC were 405 mV and 138.0 mW/m, respectively. In contrast, the maximum output voltage and maximum power density of the second stage are 105 mV and 14.7 mW/m, respectively.
人工湿地-微生物燃料电池（CW-MFC）因其兼具废水处理和能源回收的双重功能而备受关注。然而，其在处理高浓度废水时的性能会因阴极溶解氧减少和电子受体不足而降低。本研究将两个带有阴极曝气的 CW-MFC 系统串联，考察了曝气速率和水力停留时间（HRT）对高浓度废水中污染物去除和发电性能的影响。结果表明，与未曝气条件相比，曝气分别提高了 NH-N 和 TP 的去除率 45.0-49.8%和 11.5-18.0%。同时，COD 的去除率没有明显变化。曝气增强了系统的输出电压和功率密度，尤其是第一级 CW-MFC，将产电性能提高了 1 到 2 个数量级。增加 HRT 可以提高系统对高浓度废水的污染物处理效率和发电性能。然而，将 HRT 延长至 2 天对提高去除效率贡献不大。在优化条件下，两级串联 CW-MFC 系统对 COD、NH-N 和 TP 的总去除率最高分别可达 99.3±0.2%、92.4±1.6%和 79.5±3.4%。同时，第一级 CW-MFC 的最大输出电压和最大功率密度分别为 405 mV 和 138.0 mW/m3。相比之下，第二级的最大输出电压和最大功率密度分别为 105 mV 和 14.7 mW/m3。
