Coupled behaviors of antibiotics and antibiotic resistance genes in constructed wetlands: Mechanisms and impacts on nitrogen and phosphorus removal.

Authors

Bentuo Xu, Zhe Qian, Haowen Zhang, Mohammad Boshir Ahmed, Wenhui Qiu, Mengjie Pu, Min Zhao, Renlan Liu, Fujii Tadayuki, Xiangyong Zheng

Published in

Bioresource technology. Pages 135891. Sep 20, 2026. Epub Sep 20, 2026.

Abstract

Constructed wetlands (CWs) are widely used for wastewater treatment, but the coupled responses of antibiotic fate, antibiotic resistance genes (ARGs), and nutrient-removal stability under mixed-antibiotic exposure remain unclear. Here, we investigated antibiotic partitioning, ARG profiles, microbial communities, functional genes, nutrient removal, and residual risks in gravel, zeolite, and iron-carbon (Fe-C)/zeolite horizontal subsurface-flow CWs exposed to 19 antibiotics. Antibiotics preferentially accumulated in inlet zones, plant roots, and filler-associated biofilms. Zeolite-based systems reduced aqueous antibiotic residues but increased filler-surface retention and multidrug efflux pump genes, indicating a decoupling between antibiotic removal and resistance responses. Filler type also shaped microbial and functional responses. The Fe-C/zeolite system maintained stable total nitrogen removal and enhanced ammonia nitrogen and total phosphorus removal, indicating greater functional resilience. Partial least squares path modeling showed that nutrient removal was primarily associated with functional microorganisms and nutrient-cycling genes, with R² values of 0.82 for total nitrogen and 0.51 for total phosphorus removal. Human health risks were negligible (HQ < 1), whereas ecological and antimicrobial resistance selection risks persisted, with maximum RQ_eco and RQ_AMR values of 31.90 and 11.56, respectively. Overall, this study highlights the need for risk-oriented design of CWs to balance antibiotic removal, resistance control, and nutrient-removal resilience.

PMID:
42764026
Bibliographic data and abstract were imported from PubMed on 21 Sep 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.