Zheng Xiao-Ying, Zhu Xing, Wang Ju, Zhou Xiang, Xu Ya-Dong, Wei Cheng, Gao Ya-Jie, Zhou Gan
Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
Water Resources Service Center of Jiangsu Province, Nanjing 210029, China.
Huan Jing Ke Xue. 2018 Feb 8;39(2):758-764. doi: 10.13227/j.hjkx.201704155.
Aiming at the low pollutant removal efficiency of constructed wetlands (CWs) at low temperature in winter, three laboratory-scale vertical-flow CWs, namely unplanted CWs, ordinary CWs, and internal-electrolysis CWs, were used to investigate the nitrogen removal efficiency of municipal secondary effluent when the water temperature was 3-12℃. Moreover, the mechanism of enhanced denitrification of the new wetland was revealed through analysis of the microbial community diversity and community structure. The results showed that the internal-electrolysis CWs could make better use of the carbon sources in the municipal secondary effluent and had a higher removal rate. The effluent TN concentration was maintained at about (9±0.29) mg·L. The average TN removal rate was 42.27%, which was 17.91% and 17.33% higher than those of the unplanted CWs and ordinary CWs, respectively. The microbial activity was detected using fluorescein diacetate (FDA), and the result revealed that the microbial activity of the internal-electrolysis CWs could reach 0.224 mg·g, which was 2.6 times and 3.4 times of that of the unplanted CWs and ordinary CWs, respectively. The microbial denitrification intensity of the internal-electrolysis CWs was 2.8 times and 3.3 times of that of the unplanted and ordinary CWs, respectively. The results of high-throughput sequencing showed that the microbial community diversity of the internal electrolysis CWs was higher than those of the unplanted and ordinary CWs. Denitrification microorganisms were detected, mainly , and , as well as , which is an autotrophic denitrifying bacterium. There were obvious advantages in the total amount of denitrifying microorganisms in the internal-electrolysis CWs, as the denitrification microorganisms accounted for 7.13% of the total microbial biomass, which was 3.8 times and 8.7 times of that of the unplanted CWs and ordinary CWs, respectively.
针对人工湿地（CWs）在冬季低温时污染物去除效率较低的问题，采用三个实验室规模的垂直流人工湿地，即无植物人工湿地、普通人工湿地和内电解人工湿地，研究水温为3 - 12℃时城市二级出水的氮去除效率。此外，通过分析微生物群落多样性和群落结构，揭示了新型湿地强化反硝化的机制。结果表明，内电解人工湿地能够更好地利用城市二级出水中的碳源，具有较高的去除率。出水TN浓度维持在约（9±0.29）mg·L。平均TN去除率为42.27%，分别比无植物人工湿地和普通人工湿地高17.91%和17.33%。使用双乙酸荧光素（FDA）检测微生物活性，结果表明内电解人工湿地的微生物活性可达0.224 mg·g，分别是无植物人工湿地和普通人工湿地的2.6倍和3.4倍。内电解人工湿地的微生物反硝化强度分别是无植物人工湿地和普通人工湿地的2.8倍和3.3倍。高通量测序结果表明，内电解人工湿地的微生物群落多样性高于无植物人工湿地和普通人工湿地。检测到反硝化微生物，主要有 、 ，以及自养反硝化细菌 。内电解人工湿地中反硝化微生物总量具有明显优势，反硝化微生物占微生物总生物量的7.13%，分别是无植物人工湿地和普通人工湿地的3.8倍和8.7倍。
