外电阻值对3A-MFC产电和脱氮性能的影响

Effects of external resistance on the performance of three-anode-MFC:electricity generation and simultaneous nitrification and denitrification efficiency

构建三阳极单阴极型微生物燃料电池(three-anode microbial fuel cells,3A-MFC),该间歇流反应器通过在阳极提供有机物,在阴极提供有机物、氨氮和氧气,在产电的同时实现生物阴极同步硝化反硝化脱氮。考察了外电阻值分别为1000Ω、500Ω、150Ω、50Ω时对3A-MFC产电及脱氮性能的影响,当外电阻值为150Ω时,产电量达到最大值为583C,阳极库仑效率达到最大值为1.70%,内阻达到最小值为200Ω,此时外电阻值与内阻值最接近,产电效果最好。外电阻值由1000Ω减小到150Ω时,总氮(TN)去除率从79.7%上升到最大值为84.1%,TN去除速率从7.5mg/(L·d)上升到最大值为13.1mg/(L·d)。在一定外电阻值范围内,伴随其值的减小,电子转移速率逐渐提高,同时电对微生物的刺激作用得到增强,能够实现最佳的TN去除效率和去除速率。

A novel three-anode microbial fuel cell(3 A-MFC) was used to produce electricity by providing organic at the anode and organic, ammonia and oxygen at the cathode. Simultaneous nitrification and denitrification were efficiently achieved at the biocathode. The effects of external resistance values of 1000Ω, 500Ω, 150Ω, and 50Ω on the electricity generation and denitrification performance of 3 A-MFC were investigated. The maximum output of 583 C could be achieved at the external resistance value of 150Ω, which was 2.0, 1.6, 2.5 times of those at the external resistance value of1000Ω, 500Ω and 50Ω, respectively. Meanwhile, the anode coulombic efficiency reached a maximum value of 1.70% and the internal resistance reached a minimum value of 200Ω. At this time, the external resistance value was the closest to the internal resistance value, and the power generation reached the peak. When the external resistance decreased from 1000Ω to 150Ω, the total nitrogen(TN) removal efficiency increased from 79.7% to a maximum value of 84.1%. The TN removal rate increased from7.5 mg/(L·d) to 13.1 mg/(L·d). With the external resistance value reducing, the electron transfer rate was improved, and the stimulation of the microorganisms was enhanced. So the optimal TN removal efficiency and rate were achieved.