1. Microbe-mediated simultaneous nitrogen reduction and sulfamethoxazole/N-acetylsulfamethoxazole removal in lab-scale constructed wetlands.
- Author
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Zhang, Weihang, Guan, Aomei, Peng, Qiang, Qi, Weixiao, and Qu, Jiuhui
- Subjects
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CONSTRUCTED wetlands , *MICROPOLLUTANTS , *AMMONIUM , *DENITRIFICATION , *NITROGEN , *DRUG resistance in bacteria , *NITROUS oxide , *DENITRIFYING bacteria - Abstract
• Both SMX and N-SMX exposure inhibited denitrification and DNRA rates in a short time. • Denitrification and DNRA rates recovered under SMX/N-SMX exposure in a long time. • The removal of nitrogen, SMX, and N-SMX can be achieved simultaneously. • Nitrogen-reducing bacteria that also degrade antibiotics were detected. 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. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2023
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