Abstract:

In this study, an innovative constructed wetland-microbial electrolytic cell coupling system (CW-MEC) was developed, and the performance of CW-MEC on treating domestic sewage under the different conditions of cathode aeration and hydraulic retention time (HRT) were investigated. The results showed that the COD removal rate of CW-MEC cathode and anode decreased from 91.11%±7.76%, 86.58%±9.54% to 77.81%±14.84%, 81.44%±11.11%, and ammonia nitrogen removal rates from 58.54%±5.8%, 58.22%±5.03% to 48.04%±12.94% and 48.27%±13.40%. Using additional aeration in the cathode would increase the COD removal rate of C-CW-MEC and A-CW-MEC and the NH₄⁺-N removal rate of C-CW-MEC to 89.51%±3.92%, 82.40%±1.63% and 71.51%±16.44%, respectively. While NH₄⁺-N removal rate of A-CW-MEC was not affected by this condition. When the cathode aeration conditions were added, nitrate nitrogen accumulation began to occur in the cathode and anode of the system, while the nitrate nitrogen content of C-CW-MEC was significantly lower than that of the control group (C-CW- MFC). Through electrochemical performance analysis of both the systems,CW-MEC has lower internal resistance than CW-MFC. Moreover, the microbial diversity analysis showed that the CW-MEC system has richer microbial diversity than the CW-MFC system.

Key words: constructed wetland, microbial electrolytic cell, aeration, hydraulic retention time, microbial diversity

摘要：

实验构建了人工湿地-微生物电解池耦合系统（CW-MEC），并考察了CW-MEC在阴极有无曝气及不同水力停留时间（HRT）的条件下对生活污水的处理效果。实验结果显示，降低HRT会让CW-MEC阴极、阳极的COD去除率由91.11%±7.76%、86.58%±9.54%降低为77.81%±14.84%、81.44%±11.11%，氨氮去除率由58.54%±5.80%、58.22%±5.03%降低为48.04%±12.94%、48.27%±13.40%；阴极增加曝气会让CW-MEC阴极、阳极的COD去除率分别提高到89.51%±3.92%、82.40%±1.63%，阴极氨氮去除率提高到71.51%±16.44%，而阳极氨氮去除率不受影响；增加阴极曝气条件后，系统阴、阳极开始有硝酸盐氮积累，而CW-MEC阴极的硝酸盐氮含量明显低于对照组（CW-MFC）；通过电化学性能分析，相对于CW-MFC系统，CW-MEC具有更低的内阻；通过微生物多样性分析，CW-MEC系统具有更丰富的微生物多样性。

关键词: 人工湿地, 微生物电解池, 曝气, 水力停留时间, 微生物多样性