Zhang Fule, Wang Jinlong, Huang Dekun, Zhong Qiangqiang, Yu Tao, Du Jinzhou
State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China.
Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China.
Environ Sci Technol. 2023 Aug 15;57(32):12033-12041. doi: 10.1021/acs.est.3c03597. Epub 2023 Aug 2.
The behavior and source of Sr in the coastal ocean remain uncertain. Here, we investigated the distributions of Sr in coastal fresh groundwater, river water, pore water, and seawater in three bays along the southeastern coast of China between 2019 and 2021 and evaluated the potential of submarine groundwater discharge (SGD) as a source of coastal Sr. The Sr activity in coastal fresh groundwater was higher than that in river water and seawater, while the Sr activity in pore water was comparable to that in adjacent seawater. In addition, nonconservative mixing behavior of Sr along the salinity gradient between river water and seawater was observed. These observations indicated that fresh SGD may serve as an additional source of Sr in coastal seawater. Combining our groundwater Sr data with the reported fresh SGD flux data, the estimated fresh SGD-derived Sr fluxes into the three bays were comparable to or even higher than those supplied by riverine sources. These results revealed that fresh SGD is a major but overlooked source of Sr in the coastal ocean. This subterranean pathway for transport of Sr to the coastal ocean should be considered in the monitoring and risk assessment of coastal areas, especially those near nuclear facilities.
沿海海洋中锶的行为和来源仍不确定。在此，我们调查了2019年至2021年期间中国东南沿海三个海湾的沿海淡水地下水、河水、孔隙水和海水中锶的分布，并评估了海底地下水排放（SGD）作为沿海锶源的潜力。沿海淡水地下水中的锶活度高于河水和海水中的锶活度，而孔隙水中的锶活度与相邻海水中的锶活度相当。此外，还观察到锶在河水和海水之间的盐度梯度上的非保守混合行为。这些观察结果表明，新鲜的SGD可能是沿海海水中锶的另一个来源。将我们的地下水锶数据与报告的新鲜SGD通量数据相结合，估计进入三个海湾的新鲜SGD衍生的锶通量与河流来源提供的通量相当，甚至更高。这些结果表明，新鲜的SGD是沿海海洋中锶的一个主要但被忽视的来源。在沿海地区，特别是靠近核设施的地区的监测和风险评估中，应考虑这种将锶输送到沿海海洋的地下途径。
