模拟水流环境中抗生素的行为特征与归宿

利用香港理工大学水动力学实验室的大型流动水槽(FLUME)模拟动态水流环境，研究了4种不同类型的抗生素(红霉素、罗红霉素、氧氟沙星和磺胺甲唑)在动态和静态水体与沉积物之间的交换与配分，初步探明了抗生素类药物在河流环境中的行为及归宿. 结果显示:在水流环境下，抗生素被迅速吸附到水体中悬浮的颗粒物和表层沉积物中，并可通过剪切力作用被吸附到次表层沉积物中. 而在静止水体中，仅有少量的抗生素被吸附到表层沉积物中. 氧氟沙星显示出强的吸附特性(DT50≥22 d)，具有高的吸附系数(Kd)，而磺胺甲唑的吸附能力较弱. 在FLUME系统中，氧氟沙星具有适中的持久性，其他3种药物显示出弱的持久性；而在静止系统中，4种药物均显示出适中的持久性. 抗生素在水流环境中的持久性要低于静止环境. 颗粒物的吸附与自身的代谢是抗生素在水流环境中的主要归宿. 

Behavior and Fate of Antibiotics in a Lid-driven Elongated Annular Flume

The environmental behavior and fate of four different antibiotics in both simulated riverine and quiescent environments were investigated. A Lid-driven Elongated Annular Flume built by the Laboratory for Hydrodynamics, Hong Kong Polytechnic University, was used to mimic the riverine environment. The results showed that the antibiotics were sorbed to suspended particle and surface sediments quickly, and could sorb to the subsurface through shear action in the riverine environment. However, only a few antibiotics were sorbed to the surface sediments in the quiescent environment. The adsorption of ofloxacin (OFL) into the sediment was particularly strong, having a bigger adsorption coefficient (Kd), while the adsorption of sulfamethoxazole (SMZ) was found to be weak. OFL displayed a moderate persistence with a DT₅₀ value in the flume system sediment ≥22　d, while others displayed less persistence. However, all antibiotics displayed moderatepersistence in the quiescent environment. Antibiotics displayed less persistence in the riverine environment than in the quiescentenvironment. Adsorption to particles and metabolism were the main fates of antibiotics in the riverine environment.