摘要

       抗生素的大量使用导致其不断释放到环境中，并随后广泛传播抗生素抗性基因（ARGs），从而对公众健康构成潜在风险。尽管垂直上流式人工湿地 (VUF-CW) 已广泛用于处理偏远或农村地区的废水，但很少有研究评估将 VUF-CW 应用于处理含抗生素废水时 ARG 传播的潜在风险。在这项研究中，在三个实验室规模的 VUF-CW 中评估了两种典型抗生素（磺胺甲恶唑 (SMX) 和四环素 (TC)）的去除性能和 ARGs 的归宿。结果表明，SMX 和 TC 均可实现高去除效率 (>98%)。然而，抗生素的暴露导致大量 ARG（主要是 sul 和 tet 相关基因），即使随着手术时间的增加丰度也会增加。 ARGs的丰度与VUF-CWs不同层中SMX和TC的积累呈正相关，其中由于抗生素暴露浓度最高，tet和sul基因在底层的丰度最高。在流出物中观察到 tet 基因的丰度与抗生素浓度之间呈正相关。尽管流出液中 ARGs 的丰度低于湿地介质中的 ARGs，但流出液中 ARGs 的存在仍可能对公众健康构成威胁。需要进一步研究以探索从 VUF-CWs 中消除 ARGs 的有效控制策略。

       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/abs/pii/S0045653518306441