人工湿地—微生物燃料电池强化尾水脱氮产电效能

Enhanced Nitrogen Removal and Electricity Generation Efficiency of Constructed Wetland-Microbial Fuel Cells for Purification of Tail Water from Wastewater Treatment Plant

采用人工湿地—微生物燃料电池工艺(CW—MFCs)处理城市污水厂尾水,强化脱氮并产生电能。分别以氨氮(Ⅰ号反应器)和硝态氮(Ⅱ号反应器)作为单一氮源,考察了两组反应器的COD、氨氮、硝态氮去除率及输出电压。结果表明,Ⅰ号反应器的COD去除率高于Ⅱ号反应器,最高达到78.81%;两组装置对氨氮/硝态氮的去除率均平稳上升;Ⅰ号反应器的产出电压和最大功率密度分别达到了126 mV和6.01 mW/m^(3),高于Ⅱ号反应器(58 mV、1.12 mW/m^(3))。通过检测DO、COD和氮浓度的分布发现,Ⅰ号反应器中的DO分布梯度大于Ⅱ号反应器,COD的去除主要发生在阳极区,硝化反应主要发生在阴极区,反硝化反应主要发生在阳极区。

The tail water from wastewater treatment plant was treated by constructed wetland-microbial fuel cells(CW-MFCs) to enhance nitrogen removal and electricity generation. Ammonia nitrogen(reactor Ⅰ) or nitrate nitrogen(reactor Ⅱ) was applied as a single nitrogen resource, and COD and ammonia nitrogen/nitrate nitrogen removal efficiency and output voltage of the two reactors were investigated. The COD removal efficiency of reactor Ⅰwas higher than that of reactor Ⅱ, which was up to 78.81%. The ammonia nitrogen and nitrate nitrogen removal efficiencies increased steadily in the two reactors. In addition, the output voltage and maximum power density of reactor Ⅰ were 126 mV and 6.01 mW/m^(3), respectively, which were higher than those of reactor Ⅱ(58 mV and 1.12 mW/m^(3)). The distribution of DO, COD and nitrogen concentrations showed that DO gradient in reactor Ⅰwas higher than that in reactor Ⅱ, COD was mainly removed in anode region, and nitrification and denitrification mainly occurred in cathode region and anode region, respectively.