School of Marine Science and Engineering, Nanjing Normal University, Nanjing, 210023, China; Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
J Environ Manage. 2021 Sep 1;293:112953. doi: 10.1016/j.jenvman.2021.112953. Epub 2021 Jun 5.
Antibiotics receive many concerns since their negative environmental impacts are being revealed, especially in aqua-agricultural areas. Rainfall events are responsible for transferring excess contaminants to receiving waters. However, the understanding of antibiotics transport and fate responding to rainfall events was constrained by limited event-based data and lacking integrated consideration of dissolved and particulate forms. We developed an intensive monitoring strategy to capture responses of fourteen antibiotics to different types of rainfall events and inter-event low flow periods. Pollutant-rich suspended particles, as high as 1471 ng/g, were found in low flow periods while the very heavy rainfall events and consecutive rainfall events stimulated the release of antibiotics from eroded soil particles to river water. Therefore, these rainfall events drove radical increase of dissolved antibiotic concentration up to 592 ng/L and total flux up to 25.0 g/d. Sulfonamides were particularly sensitive to rainfall events because of their residues in manure-applied agricultural lands. Transport dynamics of most antibiotics were accretion whereas only clarithromycin exhibited a dilution pattern by concentration-discharge relationships. Aquaculture ponds were inferred to significantly contribute tetracycline, oxytetracycline, and clarithromycin. Conventional contaminants were compared to discriminate potential sources of antibiotics and imply effective catchment management. The results provided novel insights into event-based drivers and dynamics of antibiotics and could lead to appropriate management strategy.
抗生素因其负面的环境影响而备受关注，尤其是在水产养殖区。降雨事件是导致过量污染物转移到受纳水体的原因。然而，由于基于事件的数据有限，以及缺乏对溶解态和颗粒态形式的综合考虑，对抗生素在降雨事件中的传输和归宿的理解受到限制。我们开发了一种强化监测策略，以捕捉 14 种抗生素对不同类型降雨事件和事件间低流量期的响应。在低流量期发现了污染物丰富的悬浮颗粒，高达 1471ng/g，而特大暴雨事件和连续降雨事件刺激了从侵蚀土壤颗粒向河水释放抗生素。因此，这些降雨事件将溶解态抗生素浓度推高至 592ng/L，总通量推高至 25.0g/d。由于其在施粪农田中的残留，磺胺类药物对降雨事件特别敏感。大多数抗生素的输运动态为积累，而只有克拉霉素通过浓度-流量关系表现出稀释模式。水产养殖池塘被推断为四环素、土霉素和克拉霉素的重要来源。通过比较常规污染物来区分抗生素的潜在来源，并暗示有效的集水区管理。研究结果为基于事件的抗生素驱动因素和动态提供了新的见解，并可能导致制定适当的管理策略。
