阳极材料对6L微生物燃料电池性能及有机废水处理效果的影响

Effects of Anode Materials on Electricity Generation and Organic Wastewater Treatment of 6L Microbial Fuel Cells

阳极材料是影响微生物燃料电池实用化的关键因素之一.本文以碳刷、碳布或石墨毡阳极和泡沫镍空气阴极制成紧凑式6 L单室双空气阴极微生物燃料电池(MFC),研究不同阳极材料对电池启动过程和运行以乙酸钠为基质的人工废水和实际屠宰废水的产电性能和废水处理效果的影响,比较了单位阳极成本的产电效益.结果表明:阳极材料对紧凑式MFC的启动过程没有明显影响;在产电性能方面,碳刷阳极MFC在人工废水和屠宰废水中的输出功率密度最高,分别为(56.3±1.8)W·m^(-3)和(19.5±0.8)W·m^(-3),其次为碳布阳极MFC,分别为(46.0±1.7)W·m^(-3)和(16.9±0.6)W·m^(-3),最差的是石墨毡阳极MFC,分别为(40.8±1.5)W·m^(-3)和(11.9±0.5)W·m^(-3);在废水处理效果方面,不同阳极MFC在运行人工废水或屠宰废水时COD去除率没有明显差别,均在90%左右.碳刷阳极MFC所产生的经济效益最高,在运行乙酸钠和屠宰废水时分别为(3.44±0.08)m W·元-1和(0.97±0.05)m W·元-1,分别比碳布MFC和石墨毡MFC高18.6%、12.8%和38.7%、80%.本研究结果说明碳刷是微生物燃料电池实用化过程中最合适的阳极材料.

Anode material is one of the most important factors on the application of microbial fuel cells for wastewater treatment due to its key role in forming exoelectrogenic biofilm and transferring electrons along with the high investment cost. In this study, carbon brush （CB）, carbon cloth （CC） and graphite felt （GF） were investigated as alternative anode materials for 6 L single-chamber dual air-cathode microbial fuel cells （MFCs） in terms of starting-up rate and electricity production with artificial wastewater and slaughter wastewater. The cost effectiveness of anode materials was also evaluated. The results showed that anode materials had no obvious effect on the start-up of MFC. All MFCs finished their started-up on day 24. Using artificial wastewater[acetate 1 g·L^-1 in 50 mmol·L^-1 phosphate buffer （PBS）] as substrate, the maximum power densities for the CB, CC and GF-MFCs were （56.3±1.8） W·m^-3, （46.0±1.7） W·m^-3, and （40.8±1.5） W·m^-3, while with slaughter wastewater MFCs could produce （19.5±0.8） W·m^-3, （16.9±0.6） W·m^-3, and （11.9±0.5） W·m^-3, respectively. COD removals of all the MFCs were approximately 90% with both artificial wastewater and slaughter wastewater. The CB-MFCs had a cost of （3.44±0.08） mW·yuan-1 with the artificial wastewater and （0.97±0.05） mW·yuan-1 with slaughter wastewater, which were 18.6%, 12.8% higher than that of CC-MFCs and 38.7%, 80% higher than that of GF-MFCs, respectively. These results demonstrate that carbon brush is the most suitable material used in large-scale MFC.