Effect of microplastics concentration and size on pollutants removal and antibiotic resistance genes (ARGs) generation in constructed wetlands: a metagenomics insight
Lin Liang, Weiliang Pan, Merui Mu, Lin Zhang, Xiangyu Yang, Ruina Zhang, Lianfeng Du, Xuan Guo
{"title":"Effect of microplastics concentration and size on pollutants removal and antibiotic resistance genes (ARGs) generation in constructed wetlands: a metagenomics insight","authors":"Lin Liang, Weiliang Pan, Merui Mu, Lin Zhang, Xiangyu Yang, Ruina Zhang, Lianfeng Du, Xuan Guo","doi":"10.1016/j.jhazmat.2024.136555","DOIUrl":null,"url":null,"abstract":"The accrual of microplastics (MPs) and antibiotics poses synergistic threats to the environment. This study systemically examined the effect of environmental-level (μg/L) MPs (90–110 μm) and nanoplastics (NPs, 700<!-- --> <!-- -->nm) on constructed wetlands (CWs) treating oxytetracycline-contaminated wastewater <em>via</em> metagenomics analysis. Polystyrene (PS) MPs notably hindered the removal of nitrogen, phosphorus, and oxytetracycline, particularly at high level (1000<!-- --> <!-- -->μg/L), with removal rates of 73.34%, 59.59%, and 99.34%, respectively. Among them, the removal of NH<sub>4</sub><sup>+</sup>-N decreased the most in comparison to CK, at 15.26%. Antibiotic resistance genes (ARGs) copies/16S rRNA ranged from 0.26 to 0.42 in CWs, exceeding that found in rivers by a factor of 1.5 to 2.5 times. The relative abundance of multidrug resistance genes (<em>mdtB</em>, <em>acrB</em>, <em>mexF</em>, <em>mdtC,</em> and <em>mexT</em>) and tetracycline resistance genes (<em>txtA</em>, <em>tetG,</em> and <em>tetP</em>) exhibited a pronounced increase under MPs exposure, ranging from 0.06 to 0.14 and 0.01 to 0.08 copies/16S rRNA, respectively. Redundancy and network analyses emphasized robust associations among contaminant reduction, ARG abundance, and microbial community. Partial least squares path modeling indicated MPs exerted a more profound influence on pollutant removal (coefficient = 0.8194), microbial community (coefficient = 0.3358) and ARGs dissemination (coefficient = 0.6566) compared to NPs. MPs concentrations significantly affects pollutants removal and ARGs proliferation, and MPs with larger sizes amplified ARG dissemination. This research highlights the influence of MPs on CW-mediated wastewater treatment and ARGs accumulation, offering valuable insights for developing ecological wastewater treatment strategies tailored to multi-pollutant scenarios. These insights are fundamental in developing sustainable solutions to the adverse impacts of MPs on ecosystems.","PeriodicalId":361,"journal":{"name":"Journal of Hazardous Materials","volume":"35 1","pages":""},"PeriodicalIF":12.2000,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Hazardous Materials","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1016/j.jhazmat.2024.136555","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
The accrual of microplastics (MPs) and antibiotics poses synergistic threats to the environment. This study systemically examined the effect of environmental-level (μg/L) MPs (90–110 μm) and nanoplastics (NPs, 700 nm) on constructed wetlands (CWs) treating oxytetracycline-contaminated wastewater via metagenomics analysis. Polystyrene (PS) MPs notably hindered the removal of nitrogen, phosphorus, and oxytetracycline, particularly at high level (1000 μg/L), with removal rates of 73.34%, 59.59%, and 99.34%, respectively. Among them, the removal of NH4+-N decreased the most in comparison to CK, at 15.26%. Antibiotic resistance genes (ARGs) copies/16S rRNA ranged from 0.26 to 0.42 in CWs, exceeding that found in rivers by a factor of 1.5 to 2.5 times. The relative abundance of multidrug resistance genes (mdtB, acrB, mexF, mdtC, and mexT) and tetracycline resistance genes (txtA, tetG, and tetP) exhibited a pronounced increase under MPs exposure, ranging from 0.06 to 0.14 and 0.01 to 0.08 copies/16S rRNA, respectively. Redundancy and network analyses emphasized robust associations among contaminant reduction, ARG abundance, and microbial community. Partial least squares path modeling indicated MPs exerted a more profound influence on pollutant removal (coefficient = 0.8194), microbial community (coefficient = 0.3358) and ARGs dissemination (coefficient = 0.6566) compared to NPs. MPs concentrations significantly affects pollutants removal and ARGs proliferation, and MPs with larger sizes amplified ARG dissemination. This research highlights the influence of MPs on CW-mediated wastewater treatment and ARGs accumulation, offering valuable insights for developing ecological wastewater treatment strategies tailored to multi-pollutant scenarios. These insights are fundamental in developing sustainable solutions to the adverse impacts of MPs on ecosystems.
期刊介绍:
The Journal of Hazardous Materials serves as a global platform for promoting cutting-edge research in the field of Environmental Science and Engineering. Our publication features a wide range of articles, including full-length research papers, review articles, and perspectives, with the aim of enhancing our understanding of the dangers and risks associated with various materials concerning public health and the environment. It is important to note that the term "environmental contaminants" refers specifically to substances that pose hazardous effects through contamination, while excluding those that do not have such impacts on the environment or human health. Moreover, we emphasize the distinction between wastes and hazardous materials in order to provide further clarity on the scope of the journal. We have a keen interest in exploring specific compounds and microbial agents that have adverse effects on the environment.