Sea-level-rise-induced flooding drives arsenic release from coastal sediments
Sea-level-rise-induced flooding drives arsenic release from coastal sediments
复制标题
海平面上升引起的洪水导致沿海沉积物中砷的释放
DOI：
10.1016/j.jhazmat.2021.127161
复制
发表时间：
2022
影响因子：
13.6
通讯作者：
Sparks, Donald L.
中科院分区：
文献类型：
--
作者：
Izaditame, Fatemeh;Siebecker, Matthew G.;Sparks, Donald L.
海平面上升（SLR）对海岸带水文地质系统、海洋地球化学过程和海岸带污染物的归宿有着重要的影响。然而，SLR引起的扰动对沿海污染物移动的影响尚未完全了解。在这项研究中，SLR引起的洪水对砷和选定的危险化学品的浓度和形态的影响进行了研究，使用极端污染的沉积物（5-6%的As）收集从城市沿海站点在威尔明顿，DE，美国。污染物从沉积物中的释放进行了监测之前，期间和之后的洪水与不同的强度（底部剪切应力），通过实验室为基础的侵蚀室实验。显着增加释放的As（高达150%）和NO3（高达50%）从沉积物中的剪切应力水平，通常在河口测量被发现。有毒化学品从污染的沿海沉积物的释放，因此不限于极端的洪水事件，但可以发生在全年。结果还表明，即使在洪水之后，污染物的溶解浓度仍然相当高。因此，SLR引起的洪水不仅在侵蚀事件期间，而且在更长的时间尺度上增加污染物的释放。在此提出的释放机制有助于提高沿海水污染的风险评估，气候变化和SLR继续发生。
Sea-level rise (SLR) has a vital influence on coastal hydrogeological systems, biogeochemical processes, and the fate of coastal contaminants. However, the effects of SLR-induced perturbations on the mobilization of coastal pollutants are not fully understood. In this study, the impact of SLR-induced flooding on the concentration and speciation of arsenic and selected hazardous chemicals is investigated using exceedingly contaminated sediments (5–6% As) collected from an urban coastal site in Wilmington, DE, USA. The release of contaminants from sediments was monitored before, during, and after flooding with different intensities (bottom shear stresses) through laboratory-based erosion chamber experiments. Significantly increased release of As (up to 150%) and NO3(up to 50%) from sediments at shear stress levels typically measured in estuaries were found. The release of toxic chemicals from contaminated coastal sediments is thus not restricted to extreme flooding events but can occur throughout the year. The results also suggest that the dissolved concentrations of pollutants continue to be considerably high even after the flooding. SLR-induced flooding can hence increase the release of contaminants not only during erosion events but over longer timescales. The release mechanism proposed here contributes to improving the risk assessment of coastal water pollution as climate change and SLR continue to occur.