微生物燃料电池处理偶氮含盐废水的产电性能和降解过程

Research on the electricity production performance and degradation process of microbial fuel cell treating azo-dye saline wastewater

偶氮含盐废水生化处理流程复杂、电耗高,且降解机理尚不明确。本研究基于酸性重铬酸钾法水热处理获取改性阳极,进而构建微生物燃料电池(microbial fuel cell,MFC)对偶氮含盐废水进行处理。考察了不同二价阴离子对MFC产电性能和降解有机物效果的影响,并探究了MFC对直接红13的降解机理。结果表明,偶氮含盐废水中含有硫酸钠时的产电性能高于含有碳酸钠的情况,MFC最大功率密度为265.38mW/m^(2)、最大电流密度为1.10A/m^(2);MFC处理偶氮含盐废水时,对直接红13的去除率低于无额外添加盐时的效果(71.13%),对葡萄糖共基质的降解影响程度为:添加硫酸钠>添加碳酸钠>无额外添加盐。微生物群落和降解产物分析表明,MFC阳极生物膜通过变形菌门、拟杆菌门等微生物的协同作用实现了对直接红13的生物电化学降解,产电下降解产物以还原产物芳香胺为主。

The biochemical treatment process of azo-dye saline wastewater was complicated, and had the problems of the electricity consumption and unclear degradation mechanism. In this research, being based on the acidic-potassium-dichromate-method hydrothermal treatment, the modified anode was obtained and then was applied to construct microbial fuel cell to treat azo-dye saline wastewater. The effects of different divalent anions on the electricity generation performance and the organics degradation of MFC were investigated, and the degradation mechanism of Direct Red 13 by MFC was also explored. The results showed that when the inorganic salt in the azo-dye saline wastewater was sodium sulfate, the maximum power density of MFC could reach 265.38m W/m^(2), and the maximum current density was 1.10A/m^(2),which was higher than that of the wastewater containing sodium carbonate. As the wastewater with additional salt, the removal rate of Direct Red 13 by MFC was much lower than that without additional(71.13%). The order of the removal efficiency of glucose was sodium sulfate > sodium carbonate > no additional. Analysis of microbial communities and degradation products showed that, the anode biofilm realized the bio-electrochemical degradation of Direct Red 13 through the synergistic effect of microorganisms like Proteobacteria and Bacteroides, and the degradation products were mainly reduced products(aromatic amines) under electricity generation.