Cao Mengjing, Zhang Yongxiang, Zhang Yan
Faculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology Beijing 100124 China
Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology Beijing 100124 China.
RSC Adv. 2021 Sep 22;11(50):31364-31372. doi: 10.1039/d1ra05500c. eCollection 2021 Sep 21.
A novel and amplifying anaerobic electrochemical membrane bioreactor (AnEMBR, R2) was constructed and operated for a long time (204 days) with synthetic glucose solution having an average chemical oxygen demand (COD) of 315 mg L, at different applied voltages and room temperatures. More than twice sodium bicarbonate was added for maintaining a pH of around 6.7 in the supernatant of the reactor R2, close to that of a control reactor called anaerobic membrane bioreactor (AnMBR, R1), after 138 days. And the transmembrane pressure (TMP) for the R2 system was only 0.534 bar at the end of operation and 0.615 bar for the R1 system. Although the electrostatic repulsion force contributed to pushing away the pollutants (proteins, polysaccharose and inorganic salt deposits, and so on), more microorganisms adsorbed and accumulated on the membrane surface after the whole operation, which might result in a rapid increase in membrane filtration resistance in the long-term operation. There were much more exoelectrogenic bacteria, mainly Betaproteobacteria, Deltaproteobacteria and Grammaproteobacteria, on the cathode and the dominant methanogen content on the cathode was three times higher than the AnMBR. The study provides an important theoretical foundation for the application of AnEMBR technology in the treatment of low organic strength wastewater.
构建了一种新型的放大式厌氧电化学膜生物反应器（AnEMBR，R2），并使用平均化学需氧量（COD）为315 mg/L的合成葡萄糖溶液在不同施加电压和室温下长期运行（204天）。运行138天后，添加了超过两倍量的碳酸氢钠以维持反应器R2上清液的pH值在6.7左右，接近对照反应器厌氧膜生物反应器（AnMBR，R1）的pH值。运行结束时，R2系统的跨膜压力（TMP）仅为0.534 bar，而R1系统为0.615 bar。尽管静电排斥力有助于推开污染物（蛋白质、多糖和无机盐沉积物等），但整个运行后更多微生物吸附并积聚在膜表面，这可能导致长期运行中膜过滤阻力迅速增加。阴极上有更多的产电细菌，主要是β-变形菌纲、δ-变形菌纲和γ-变形菌纲，阴极上的优势产甲烷菌含量比AnMBR高3倍。该研究为AnEMBR技术在处理低有机强度废水方面的应用提供了重要的理论基础。
