Wang Xinyi, Zhu Hui, Yan Baixing, Shutes Brian, Bañuelos Gary, Cheng Rui
Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China.
Jilin Provincial Engineering Center of CWs Design in Cold Region & Beautiful Country Construction, Changchun, 130102, China.
Environ Sci Pollut Res Int. 2021 Apr;28(14):18089-18101. doi: 10.1007/s11356-020-11937-z. Epub 2021 Jan 6.
Nitrogen removal in constructed wetlands (CWs) may be inhibited by salinity. The clarification of the response of microbial community to salt stress is a premise for developing strategies to improve nitrogen removal efficiency in CWs under saline conditions. Results showed that the ammonia nitrogen (NH-N), nitrate nitrogen (NO-N), and total nitrogen (TN) removal percentages significantly (p < 0.05) decreased in CWs with increasing salinity. The structure and abundance of the microbial community varied with different salinity levels and sampling depths in CWs. Compared with a non-saline condition, the abundances of some bacteria with a denitrification function (e.g., Arthrobacter) significantly (p < 0.05) decreased in CWs under saline conditions (i.e., EC of 15 and 30 mS/cm). Aerobic bacteria (e.g., Sphingomonas) exhibited more abundance in soil and upper gravel samples in CWs than those in bottom gravel samples, while the abundance of some denitrifying bacteria (e.g., Thauera and Azoarcus) was significantly (p < 0.05) higher in bottom gravel samples compared with soil and upper gravel samples, respectively. This study provides both microbiological evidence for explaining the impact of salt stress on nitrogen removal in CWs and scientific reference for developing enhanced strategies to improve the nitrogen removal capacity of CWs.
人工湿地（CWs）中的氮去除可能会受到盐分的抑制。阐明微生物群落对盐胁迫的响应是制定在盐渍条件下提高人工湿地氮去除效率策略的前提。结果表明，随着盐度的增加，人工湿地中氨氮（NH-N）、硝态氮（NO-N）和总氮（TN）的去除率显著（p < 0.05）下降。微生物群落的结构和丰度随人工湿地不同盐度水平和采样深度而变化。与非盐渍条件相比，在盐渍条件下（即电导率为15和30 mS/cm）的人工湿地中，一些具有反硝化功能的细菌（如节杆菌）的丰度显著（p < 0.05）下降。需氧细菌（如鞘氨醇单胞菌）在人工湿地的土壤和上部砾石样品中的丰度高于底部砾石样品，而一些反硝化细菌（如陶厄氏菌属和偶氮弧菌属）在底部砾石样品中的丰度分别显著（p < 0.05）高于土壤和上部砾石样品。本研究既为解释盐胁迫对人工湿地氮去除的影响提供了微生物学证据，也为制定提高人工湿地氮去除能力的强化策略提供了科学参考。
