Abstract To further reveal plutonium transport and scavenging processes within the sediments of the East China Sea (ECS), this study analyzed spatial variations of plutonium in surface sediments and explored factors influencing the spatial pattern of Pu in the ECS. From the perspective of the whole ECS, the 239+240Pu concentrations and 240Pu/239Pu atom ratios increased with the distance from the river mouth but decreased toward the outer shelf. Additionally, high 240Pu/239Pu atom ratios could be seen along the flow direction of the Changjiang Diluted Water. The results indicated that under the influence of regional hydrodynamics, the spatial pattern of Pu in the ECS may be consistent with the dispersal of the Yangtze River-derived sediments. The source of Pu from PPG (Pacific Proving Ground) transported by the North Equatorial Current and the Kuroshio Current in the Yangtze River estuary was 41%.

中文翻译：

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长江口及邻近东海沉积物中钚的分布与运移

摘要 为进一步揭示东海沉积物中钚的输运和清除过程，本研究分析了表层沉积物中钚的空间变化，探讨了影响东海沉积物中钚空间格局的因素。从整个ECS来看，239+240Pu浓度和240Pu/239Pu原子比随着离河口的距离增加而增加，但向着外陆架则减少。此外，沿长江稀释水的流动方向可以看到高 240Pu/239Pu 原子比。结果表明，受区域水动力影响，ECS中Pu的空间格局可能与长江源沉积物的扩散一致。