摘要

       抗生素的大量使用导致其不断释放到环境中，随后抗生素耐药基因（ARGs）广泛传播，从而对公众健康构成潜在风险。尽管垂直上流人工湿地（VUF-CWs）已广泛应用于边远地区或农村地区的废水处理，但很少有研究评估VUF-CWs处理含抗生素废水时ARG传播的潜在风险。本研究以三种实验室规模的VUF水煤浆为研究对象，对两种典型抗生素（磺胺甲恶唑（SMX）和四环素（TC））的去除效果和ARGs的归宿进行了评价。结果表明，无论是SMX还是TC，均能达到较高的去除率（>98%）。然而，抗生素的暴露导致大量ARGs（主要是sul-和tet相关基因）的存在，甚至随着手术时间的延长而增加。ARGs的丰度与VUF-CWs各层中SMX和TC的积累呈正相关，其中tet和sul基因在VUF-CWs底层由于抗生素暴露浓度最高而丰度最高。tet基因丰度与废水中抗生素浓度呈正相关。虽然污水中的ARGs含量低于湿地介质中的含量，但其存在仍可能对公众健康造成危害。进一步的研究需要探索有效的控制策略来消除VUF-CWs中的ARGs。

        The intensive use of antibiotics results in their continuous release into the environment and the subsequent widespread dissemination of antibiotic resistance genes (ARGs), thus posing potential risks for public health. Although vertical up-flow constructed wetlands (VUF-CWs) have been widely used to treat wastewater in remote or rural regions, few studies have assessed the potential risks of ARG dissemination when VUF-CWs are applied to treat wastewaters containing antibiotics. In this study, the removal performance of two typical antibiotics (sulfamethoxazole (SMX) and tetracycline (TC)) and the fate of ARGs were evaluated in three lab-scale VUF-CWs. The results indicated that high removal efficiencies (>98%) could be achieved for both SMX and TC. However, the exposure of antibiotics resulted in harboring abundant ARGs (mainly sul- and tet-related genes), even with increasing abundances with operation time. The abundances of ARGs had a positive correlation with the accumulation of SMX and TC in different layers of VUF-CWs, where the tet and sul genes have the highest abundance in the bottom layer due to the highest antibiotic exposure concentration. Positive correlations were observed between the abundance of tet gene and antibiotic concentration in effluent. Although the effluent had lower abundances of the ARGs than that in the wetland media, the occurrence of ARGs in effluent might still pose risk for public health. Further studies are required to explore effective control strategies to eliminate ARGs from VUF-CWs.

         https://www.sciencedirect.com/science/article/pii/S0045653518306441?via%3Dihub