Effect of Anode on Greenhouse Gas Emission from Microbial Cell Wetland

GAO Huijun; YU Yilei; WANG Zheng; MAO Xufeng; SUN Zhenyu

doi:10.19672/j.cnki.1003-6504.0108.25.338

Abstract：The integrated system of microbial fuel cell and constructed wetland(CWs-MFC)exhibits superior pollutant removal efficiency and lower greenhouse gas emissions compared to traditional constructed wetlands(CW).However,the influence of different anode materials on gas emissions in CWs-MFC systems remains unclear.In this study,three CWs-MFC systems with activated carbon(CW-MFC),manganese ore(MCW-MFC),and pyrite(PCW-MFC)as anodes,along with a control CW system,were constructed to analyze the dynamic patterns of greenhouse gas emissions during domes-tic wastewater treatment.Gas emission data were collected on the 4th and 7th days,and a comprehensive evaluation was conducted using the global warming potential(GWP).The results revealed that in the early stage of the experiment(day 4),the CWs-MFC systems significantly inhibited CH4 emissions.Compared to the CW system,the average CH4 emission fluxes of CW-MFC,MCW-MFC,and PCW-MFC were reduced by 59.7％,50.5％,and 120.0％,respectively(P＜0.05).The N2O and CO2 emission fluxes followed the order:PCW-MFC＞CW-MFC＞MCW-MFC＞CW.In the later stage of the experiment(day 7),CH4 emissions from PCW-MFC increased while N2O and CO2 emissions decreased,whereas CH4 emissions from MCW-MFC decreased but N2O and CO2 emissions increased.Overall,the average CH4 emissions from the CWs-MFC systems were reduced by 21.9％～127.0％compared to the CW system(P＜0.05),but N2O emissions from MCW-MFC and PCW-MFC increased by 51.6％and 226.0％,respectively.From the perspective of GWP,the GWP of MCW-MFC was re-duced by 98.1％compared to CW,while the GWP of PCW-MFC increased by 18.8％.The findings demonstrate that man-ganese ore,as an anode material,performs exceptionally well in reducing greenhouse gas emissions and lowering GWP,mak-ing it a more environmentally friendly choice.