College of Land and Environment, Shenyang Agricultural University, Shenyang, 110866, People's Republic of China.
Agro-Environmental Protection Institute, Ministry of Agriculture, MOA Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Tianjin, 300191, People's Republic of China.
Environ Sci Pollut Res Int. 2018 Jun;25(17):16900-16912. doi: 10.1007/s11356-018-1871-z. Epub 2018 Apr 5.
The microbial fuel cell (MFC) that uses a solid electrode as the inexhaustible electron acceptor is an innovative remediation technology that simultaneously generates bioelectricity. Chlorinated pollutants are better metabolized by reductive dechlorination in proximity to the cathode. Here, the removal efficiency of the herbicide metolachlor (ML) increased by 262 and 176% in soil MFCs that were spiked with 10 (C10) and 20 mg/kg (C20) of ML, respectively, relative to the non-electrode controls. The bioelectricity output of the C10 and C20 increased by over two- and eightfold, respectively, compared to that of the non-ML control, with maximum current densities of 49.6 ± 2.5 (C10) and 78.9 ± 0.6 mA/m (C20). Based on correlations between ML concentrations and species abundances in the MFCs, it was inferred that Azohydromonas sp., Sphingomonas sp., and Pontibacter sp. play a major role in ML removal around the cathode, with peak removal efficiencies of 56 ± 1% (C10) and 58 ± 1% (C20). Moreover, Clostridium sp., Geobacter sp., Bacillus sp., Romboutsia sp., and Terrisporobacter sp. may be electricigens or closely related microbes due to the significant positive correlation between the bioelectricity generation levels and their abundances around the anode. This study suggests that a directional adaptation of the microbial community has taken place to increase both the removal of chlorinated herbicides around the cathode and the generation of bioelectricity around the anode in bioelectrochemical remediation systems.
微生物燃料电池（MFC）使用固体电极作为不竭的电子受体，是一种同时产生生物电能的创新修复技术。在靠近阴极的地方，氯化污染物通过还原脱氯更好地被代谢。在这里，与非电极对照相比，分别添加 10（C10）和 20mg/kg（C20）的除草剂甲草胺（ML）的土壤 MFC 中，ML 的去除效率分别提高了 262%和 176%。与非 ML 对照相比，C10 和 C20 的生物电能输出分别增加了两倍和八倍以上，最大电流密度分别为 49.6±2.5（C10）和 78.9±0.6 mA/m（C20）。根据 MFC 中 ML 浓度与物种丰度之间的相关性，可以推断 Azohydromonas sp.、Sphingomonas sp. 和 Pontibacter sp. 在阴极周围的 ML 去除中起主要作用，其去除效率峰值分别为 56±1%（C10）和 58±1%（C20）。此外，Clostridium sp.、Geobacter sp.、Bacillus sp.、Romboutsia sp. 和 Terrisporobacter sp. 可能是电生成菌或密切相关的微生物，因为生物电能生成水平与阳极周围它们的丰度之间存在显著的正相关关系。本研究表明，微生物群落发生了定向适应，以增加阴极周围氯化除草剂的去除率和阳极周围生物电能的生成率，从而提高生物电化学修复系统的修复效率。
