School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Key Laboratory for Solid Waste Management and Environment Safety, Ministry of Education of China, Tsinghua University, Beijing 100084, China; School of Energy and Environment, Southeast University, Nanjing 210096, China.
Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
Bioresour Technol. 2017 Oct;241:812-820. doi: 10.1016/j.biortech.2017.06.031. Epub 2017 Jun 9.
To harvest electricity and mitigate methane emissions from wetlands, a novel microbial fuel cell coupled constructed wetland (MFC-CW) was assembled with an anode placing in the rhizosphere and a cathode on the water surface. Plant-mediated methane accounted for 71-82% of the total methane fluxes. The bioanode served as an inexhaustible source of electron acceptors and resulted in reduced substantial methane emissions owing to electricigens outcompeting methanogens for carbon and electrons when substrate was deficient. However, when supplying sufficient organic carbon, both electricity and methane increased, indicating that electrogenesis and methanogenesis could co-exist in harmony. Direct methane emission (diffusion/ebullition) and plant-mediated methane emission were affected by operating conditions. Methanogenesis was significantly suppressed (∼98%) at HRT of 96h and with external resistance of 200Ω, accompanied with improved coulombic efficiency of 14.9% and current density of 187mA/m. Contrarily, change of electrode polarity in the rhizosphere led to more methane efflux.
为了从湿地中获取电能并减少甲烷排放，一种新型的微生物燃料电池与人工湿地（MFC-CW）耦合系统被构建起来，其阳极位于根际，阴极位于水面上。植物介导的甲烷占总甲烷通量的 71-82%。生物阳极充当了电子受体的不竭来源，由于电生成菌在底物缺乏时与产甲烷菌争夺碳和电子，从而减少了大量的甲烷排放。然而，当供应充足的有机碳时，电能和甲烷都会增加，这表明电生成和产甲烷可以和谐共存。直接甲烷排放（扩散/鼓泡）和植物介导的甲烷排放受操作条件的影响。在水力停留时间为 96 小时和外接电阻为 200Ω的条件下，产甲烷作用显著受到抑制（约 98%），同时库仑效率提高到 14.9%，电流密度提高到 187mA/m。相反，根际电极极性的变化导致更多的甲烷逸出。
