人工湿地微生物燃料电池阳极预制及应用研究

Biofilm Prefabrication and the Applications in Constructed Wetland Microbial Fuel Cells

人工湿地微生物燃料电池(CW-MFCs)能实现有机废水处理和电能回收,输出功率密度和污染物去除效率是衡量其性能的关键指标。目前,燃料电池阳极挂膜慢、启动周期长等问题制约了其输出功率和污染物去除效果。该研究包括两方面内容:其一是以阳极生物膜为研究对象,探究了生物膜预制对微生物燃料电池产电性能的影响;其二是预制生物阳极构建微生物燃料电池,耦合人工湿地原理,组建CW-MFCs系统,应用于餐厨垃圾压缩水处理。结果表明:在恒压电化学选择压力下,阳极电化学活性菌可加速富集。恒压0.2 V预制6 d的阳极在电化学阻抗谱测试、输出电压、最大功率密度方面均优于对照组,恒压预制6 d的阳极可实现MFCs的迅速启动,且该预制阳极对应的MFCs的峰值电压以及最大功率密度分别是对照组的1.21倍和1.25倍。基于预制阳极构建的CW-MFCs系统应用于餐厨垃圾压缩水处理,水力停留时间为48 h时,出水化学需氧量、氨氮以及悬浮物的去除率可分别达到64.4%、50.8%和86.4%,系统最大输出功率密度为48.40 mW/m^(2)。

Constructed wetland microbial fuel cells (CW-MFCs) is a promising tool for the degradation of organic pollutants and simultaneous electricity recovery, the output power density and contaminant removal efficiency has been regarded as the key factors of CW-MFCs system. Currently, issues limiting the commercial development of MFCs as anticipant power generators are their low output power density as well as nagging and long start-up procedure compared to chemical fuel cells. Meanwhile, the biofilm evolution progress on MFC anodes is sluggish, which makes it hard for them to satisfy the demand of high and steady-going energy output. Herein, prefabricated anode was proposed as a novel anode concept for the MFCs, which enriching biofilms on the surface of anode surface via electrochemical selection and biofilms acclimatization. Then, the prefabricated anode was assembled to the CW-MFCs system, purifying leachate of kitchen wastes. Results showed that, based on simple consecutive electrochemical selection procedure, anode biofilms acclimatization and enriching process can be maximized accelerated and ultimately realized. The performance of anodes was closely related to prefabrication, while the prefabricated anode outperformed the control one in electrochemical tests. The maximum power density (810.20 mW/m^(2)) of the MFC equipped with the prefabricated anode delivered a 1.25-fold increase over that of the control;also, the maximum output 0.52 V, 1.21 times higher than the unfabricated one. When the hydraulic retention time was 48 h, the removal efficiency of COD, ammonia nitrogen and suspended solids has reached 64.4%, 50.8% and 86.4% respectively, the maximum power density reached 48.40 mW/m^(2).