Zhang Weihang, Guan Aomei, Peng Qiang, Qi Weixiao, Qu Jiuhui
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Water Res. 2023 Aug 15;242:120233. doi: 10.1016/j.watres.2023.120233. Epub 2023 Jun 15.
Constructed wetlands (CWs) are increasingly used to treat complex pollution such as nitrogen and emerging organic micropollutants from anthropogenic sources. In this study, the denitrification, anaerobic ammonium oxidation, dissimilatory nitrate reduction to ammonium, and nitrous oxide release rates following exposure to the frequently detected sulfonamides sulfamethoxazole (SMX) and its human metabolite, N-acetylsulfamethoxazole (N-SMX), were investigated in lab-scale CWs. Over a period of 190 d, the denitrification rates were noticeably inhibited in the SMX and N-SMX groups at week 5. Subsequently, the denitrification rates recovered, accompanied by an increase in the relevant nitrogen reduction and antibiotic resistance genes (ARGs). The composition of the microbial community also changed during this process. After the denitrification rates recovered, Burkholderia_Paraburkholderia and Gordonia exhibited a significant positive correlation with SMX exposure, which simultaneously reduced nitrate concentrations and degraded antibiotics. Burkholderia_Paraburkholderia is a key carrier of ARGs. Finally, nitrogen reduction (> 90%) and antibiotic removal (> 80%) also recovered in both SMX- and N-SMX-exposed lab-scale CWs during the operation, which revealed the interaction of SMX or N-SMX removal and nitrogen reduction.
人工湿地（CWs）越来越多地用于处理复杂污染，如来自人为源的氮和新兴有机微污染物。在本研究中，在实验室规模的人工湿地中研究了暴露于频繁检测到的磺胺类药物磺胺甲恶唑（SMX）及其人体代谢产物N-乙酰磺胺甲恶唑（N-SMX）后的反硝化、厌氧氨氧化、异化硝酸盐还原为铵以及一氧化二氮释放速率。在190天的时间里，第5周时SMX和N-SMX组的反硝化速率受到明显抑制。随后，反硝化速率恢复，同时相关的氮还原和抗生素抗性基因（ARGs）增加。在此过程中微生物群落的组成也发生了变化。反硝化速率恢复后，伯克霍尔德氏菌属_副伯克霍尔德氏菌属和戈登氏菌属与SMX暴露呈显著正相关，同时降低了硝酸盐浓度并降解了抗生素。伯克霍尔德氏菌属_副伯克霍尔德氏菌属是ARGs的关键载体。最后，在运行过程中，暴露于SMX和N-SMX的实验室规模人工湿地中的氮还原（>90%）和抗生素去除（>80%）也恢复了，这揭示了SMX或N-SMX去除与氮还原之间的相互作用。
