生物燃料电池处理生活污水同步产电特性研究

以某生活污水处理厂缺氧池活性污泥为接种体,以葡萄糖为模拟生活废水,构建双室型微生物燃料电池。利用微生物燃料电池(MFC,Microbial fuel cell)实现生活废水降解与同步产电。研究基质降解动力学及温度对MFC电极过程动力学的影响,明确微生物电化学活性、阳极传荷阻抗、阳极电势、电池产能之间的关系,考察库伦效率及COD去除率。研究结果表明,电池功率输出与基质浓度关系遵循莫顿动力学方程:P=Pmaxc/(ks+c),其中,半饱和常数ks为138.5 mg/L,最大功率密度Pmax为320.2 mW/m2。葡萄糖浓度较小时,反应遵循一级动力学规律:-dcA/dt=kcA,k=0.262 h-1。操作温度从20℃提高到35℃,生物膜电化学活性不断提高,传荷阻抗从361.2Ω减小到36.2Ω,阳极电极电势不断降低,同时,峰值功率密度从80.6 mW/m2提高到183.3 mW/m2。45℃时,产电菌活性降低,峰值功率密度减小到36.8 mW/m2。葡萄糖浓度为1 500 mg/L,温度为35℃时,MFC电化学性能最佳,稳定运行6 h后库伦效率为44.6%,COD去除率为49.2%。

Treatment of sewage and synchronous electricity generation characteristics by microbial fuel cell

A microbial fuel cell (MFC) was built using glucose as simulated domestic wastewater, using carbon felt as anode and activated anaerobic sludge as inoculum, which came from a sewage treatment plant. The sewage was treated and electricity was generated synchronously. The effect of substrate concentration and operating temperature on electrode process kinetics was examined. The relationship among electrochemical activity of microbes, charge transfer resistance, anode potential, and capacity of producing electricity was explored. The main conclusions about sewage-fuel MFC are summarized as follows: The relationship between the peak power density and substrate concentration followed Monod enzyme kinetics equation: P=P_maxc/(k_s+c), with a maximum power density (P_max) of 320.2 mW/m² and half-saturation concentration (k_s) of 138.5 mg/L. When the initial glucose concentration is less than 2 000 mg/L, the reaction follows the first order kinetics equation: -dc_A/dt=kc_A, k=0.262 h^-1. Increasing the temperature from 20 to 35 ℃, the charge transfer resistance decreases from 361.2 to 36.2 Ω, the anode electrode potential also decreases, while peak power density increases from 80.6 to 183.3 mW/m². At 45 ℃, the electrochemical activity of microbes declines, and the peak power density decreases to 36.8 mW/m². After operating steadily for 6 h, coulombic efficiency and COD removal efficiency reach a maximum of 44.6% and 49.2%, respectively, at 35 ℃ with the substrate concentration of 1 500 mg/L.