Zhang Ke, Wu Xiangling, Wang Wei, Luo Hongbing, Chen Wei, Chen Jia
School of Environment, Harbin Institute of Technology, Harbin, People's Republic of China.
College of Civil Engineering, Sichuan Agricultural University, Dujiangyan, People's Republic of China.
Environ Technol. 2023 Jan;44(4):540-551. doi: 10.1080/09593330.2021.1976846. Epub 2021 Sep 20.
In this study, effects of bioelectrochemical technique on methane emission and energy recovery, and related mechanism underlying microbial competition were investigated. The results showed that running MFC was beneficial in reducing CH emissions and promoting COD removal rates, regardless of whether the plant roots were located at the anode or the cathode. CH emission was significantly higher in open-circuit reactors (6.2 mg m h) than in closed-circuit reactors (3.1 mg m h). Plant roots at the cathode had the highest electricity generation and the lowest CH4 emissions. The highest power generation (0.49 V, 0.33 w m) and the lowest CH emissions (2.3 mg m h) were observed in the reactors where was planted with plant roots at the cathode. The role of plants in strengthening electron acceptor was greater than that of plant rhizodeposits in strengthening electron donors. Real-time quantitative PCR (q-PCR) and correlation analysis indicated that the A genes and CH emissions were positively correlated ( = 0.98, < 0.01), while no significant relationship between CH emissions and A genes was observed. Illumina sequencing revealed that more abundant exoelectrogens and denitrifying bacteria were observed when plant roots were located in cathodes. Strictly acetotrophic archae (Methanosaetaceae) were likely the main electron donor competitors with exoelectrogens. The results showed that the location of both plant species and plant roots at the electrode played an important role in CH control and electricity generation. Therefore, it is necessary to strengthen plant configuration to reduce CH emissions, to promote sustainable development of wastewater treatment.
在本研究中，研究了生物电化学技术对甲烷排放和能量回收的影响以及微生物竞争的相关机制。结果表明，运行微生物燃料电池（MFC）有利于减少CH排放并提高化学需氧量（COD）去除率，无论植物根系位于阳极还是阴极。开路反应器中的CH排放（6.2 mg m h）显著高于闭路反应器（3.1 mg m h）。阴极处的植物根系发电量最高，CH4排放量最低。在阴极种植植物根系的反应器中观察到最高发电量（0.49 V，0.33 w m）和最低CH排放（2.3 mg m h）。植物在强化电子受体方面的作用大于植物根际沉积物在强化电子供体方面的作用。实时定量聚合酶链反应（q-PCR）和相关性分析表明，A基因与CH排放呈正相关（ = 0.98， < 0.01），而未观察到CH排放与A基因之间存在显著关系。Illumina测序显示，当植物根系位于阴极时，观察到更多丰富的产电菌和反硝化细菌。严格的乙酸营养型古菌（甲烷鬃菌科）可能是与产电菌竞争的主要电子供体。结果表明，植物种类和植物根系在电极上的位置在CH控制和发电中都起着重要作用。因此，有必要加强植物配置以减少CH排放，促进废水处理的可持续发展。
