As an important link of mercury (Hg) migration and transformation from land to ocean, rivers have been significantly influenced by anthropogenic activities, resulting in unpredictable environmental influences on the basin and offshore areas. In this study, the particulate Hg content of sediments in Xiaolangdi Reservoir (XLDR), Lijin Hydrological Station, and the Yellow River estuarine area during the water-sediment regulation scheme (WSRS) period in 2018 were analyzed, the characteristics and influencing factors of particulate Hg transport were explored. Our results revealed that the transport flux of particulate Hg into the sea during WSRS was 8.7 t, accounting for 68.8 % of the annual flux. High Hg content derived from the anthropogenic sources was observed in XLDR sediment, and Hg content in sediments of the lower reaches and estuary was elevated due to the sediments were mainly from XLDR during the sediment regulation stage. Under the influence of WSRS, the Hg content in the sediments of the lower reaches to estuary continuum was affected by the variation of sediment particle size, which was caused by the difference of sediment sources. In addition, WSRS led to a change in the binding forms of Hg in sediments, from mostly binding with organic matter in the XLDR to being comprehensively restricted by organic matter, iron and manganese oxides and carbonate minerals. Therefore, the transport behaviors and deposition patterns of particulate Hg in the reservoir-downstream-estuarine continuum has a good response to the implementation process of WSRS.

中文翻译：

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2018 年黄河水泥沙调控计划期间颗粒汞沿水库-下游-河口连续体的运移


作为汞 （Hg） 迁移和从陆地向海洋转化的重要环节，河流受到人为活动的重大影响，对流域和近海地区造成不可预测的环境影响。本研究分析了 2018 年水泥沙调控方案 （WSRS） 期间小浪底水库 （XLDR）、丽津水文站和黄河河口地区沉积物的颗粒物汞含量，探讨了颗粒物汞迁移的特点和影响因素。我们的结果表明，在 WSRS 期间，颗粒汞运入海的通量为 8.7 t，占年通量的 68.8%。在 XLDR 沉积物中观察到高人为来源的 Hg 含量，并且在沉积物调节阶段，由于沉积物主要来自 XLDR，下游和河口沉积物中的 Hg 含量升高。在 WSRS 的影响下，下游至河口连续体沉积物中 Hg 含量受沉积物粒径变化的影响，这是由沉积物来源的差异引起的。此外，WSRS 导致沉积物中 Hg 结合形式的变化，从主要与 XLDR 中的有机物结合转变为受到有机物、铁和锰氧化物以及碳酸盐矿物的全面限制。因此，颗粒汞在储层-下游-河口连续体中的运移行为和沉积模式对WSRS的实施过程具有良好的响应。