State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China.
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China; Advanced Interdisciplinary Institute of Environment and Ecology, Beijing Normal University, Zhuhai, 519087, China.
Environ Pollut. 2022 Dec 15;315:120432. doi: 10.1016/j.envpol.2022.120432. Epub 2022 Oct 13.
Herbicides are ubiquitous pollutants in estuaries because of the increased demand for food and the need for intensive agricultural systems worldwide. Multi-interface partitioning processes are inadequate for the degradation products of herbicides, especially in sediment-laden river estuaries with intensive water and sediment partitioning. Therefore, the partition characteristics of atrazine and its degradation products at the surface water-suspended particulate matter (SPM), surface water-surface sediment, and SPM-surface sediment interfaces in a typical sediment-laden river estuary were analyzed, the dominant environmental factors were described, and the related mechanisms were explored. The results showed that the partitioning priority of atrazine and its degradation products was surface water > SPM > surface sediment. The partition coefficients of these three interfaces were significantly correlated. The primary degradation products and desisopropylhydroxyatrazine tended to partition into the SPM, and desethyldesisopropylatrazine tended to partition into the surface sediment. Canonical analysis and structural equation modeling indicated that temperature, salinity, sediment pH, and SPM concentrations were the main influencing factors. In the sediment-laden river estuary, the SPM concentration was the most dominant factor. The partition coefficients increased exponentially when the SPM concentration was <150 mg/L at the SPM-surface sediment interface, leading to a rapid shift in the interface proportion of atrazine and its degradation products. In the context of climate change and human activities, the SPM concentration in the estuary was decreasing, which hastened the release potential for atrazine and its degradation products from the estuarine sediment. The investigation of the partition traits of organic degradation pollutants promotes the understanding of the multi-interface transport processes in estuaries.
由于全球对食物的需求增加和对集约化农业系统的需求，除草剂成为河口普遍存在的污染物。多界面分配过程对于除草剂的降解产物是不够的，特别是在水和沉积物分配强烈的含沙河口。因此，分析了典型含沙河口地表水-悬浮颗粒物（SPM）、地表水-表层沉积物和 SPM-表层沉积物界面上莠去津及其降解产物的分配特征，描述了主要环境因素，并探讨了相关机制。结果表明，莠去津及其降解产物的分配优先顺序为地表水>SPM>表层沉积物。这三个界面的分配系数具有显著相关性。这些主要的降解产物和去异丙基羟基莠去津倾向于分配到 SPM 中，而去乙基去异丙基莠去津则倾向于分配到表层沉积物中。典范分析和结构方程模型表明，温度、盐度、沉积物 pH 值和 SPM 浓度是主要影响因素。在含沙河口，SPM 浓度是最主要的因素。当 SPM-表层沉积物界面上的 SPM 浓度<150mg/L 时，分配系数呈指数增长，导致莠去津及其降解产物在界面上的比例迅速发生变化。在气候变化和人类活动的背景下，河口的 SPM 浓度正在下降，加速了莠去津及其降解产物从河口沉积物中的释放潜力。对有机降解污染物分配特征的研究促进了对河口多界面传输过程的理解。
