Abstract:

Degradation characteristics of actual landfill leachate have been studied by Microbial electrolysis cell(MEC) coupled with carbon felt(A-MEC) and carbon brush(B-MEC),respectively. The results show that the applied voltage has a significant and positive effect on the pollutant removal rate of MEC system 48.23%±0.22% and 70.21%±1.12% of landfill leachate COD are removed by A-MEC and B-MEC, respectively, whereas 88.83%±1.19% and 84.55%±2.08% in the case of \mathrm{N}{\mathrm{H}}_{\mathrm{4}}^{+}-N. The highest current density obtained from the A-MEC and B-MEC was 11.12A/m³、12.52A/m³,Lower internal resistance is obtained for B-MEC compared to that of A-MEC system. However, both MEC systems are showing an obvious removal effect on turbidity and chroma, but the chroma removal rate of B-MEC is 47.83%±1.62% higher than that of A-MEC. The UV-vis spectra showed that the peak of the leachate treated with MEC was significantly lower than that of the initial leachate, indicating that the unsaturated bond was destroyed and the structural complexity was reduced. SEM indicated that the microorganism morphology of the carbon brush was more abundant than that of the carbon felt. The experimental results provide a new method for the efficient treatment of landfill leachate.

Key words: microbial electrolysis cell, landfill leachate, chroma, carbon brush, carbon felt, voltage

摘要：

构建了以碳毡（A-MEC）和碳刷（B-MEC）为电极材料的微生物电解池（microbial electrolysis cell, MEC）处理实际垃圾渗滤液，研究不同外加电压条件下反应器的运行特性。结果表明，外加电压对MEC系统污染物去除率有显著影响且呈正相关性，外加电压升高到1.2V时，A-MEC和B-MEC对垃圾渗滤液中COD的最大去除率分别为48.23%±0.22%和70.21%±1.12%，\mathrm{N}{\mathrm{H}}_{\mathrm{4}}^{+}-N最大去除率分别为88.83%±1.19%和84.55%±2.08%，运行时A-MEC和B-MEC的最大电流密度分别为11.12A/m³、12.52A/m³，相比于A-MEC系统，B-MEC的内阻更低；两种MEC系统对浊度和色度均有明显的去除效果，但B-MEC色度去除率比A-MEC高出47.83%±1.62%；紫外-可见光谱结果表明，两种MEC处理后垃圾渗滤液的特征波长波峰明显低于初始垃圾渗滤液，说明不饱和键被破坏，结构复杂程度下降。通过电镜扫描进一步发现碳刷电极的微生物形态要比碳毡电极丰富。本文为高效处理垃圾渗滤液提供了新的思路。

关键词: 微生物电解池, 垃圾渗滤液, 色度, 碳刷, 碳毡, 电压