The distribution of dissolved major- and trace elements in the mixing zone of the Ural River and the North Caspian waters was studied based on the natural observations data from 2016–2017. Conservative behavior was established for most of major ions (Na, K, Mg, SO4) and some trace elements (Li, Rb, Cs, Sr, Co, Ni, Cu, Zn, Sb, Ga, Y, U, B, F, Cr, Ge, Mo, W) with common parameters of relationships between their concentrations and chloride content for different years. The distribution of components of the carbonate system is controlled by chemogenic precipitation of calcium carbonate at the mouth beach. This process leads to the removal from solution up to 11–17% calcium and 6–8% hydrocarbonates carried by river runoff, and a simultaneous decrease in the pH value. Nutrients are involved in the processes of biological assimilation and regeneration. The mixing zone of the Ural River and Caspian waters is characterized by: (a) phytoplankton consumption of large amounts of silicon and nitrates (up to 58–88 and 61–67%, respectively, of their content in riverine waters), (b) removal of significant part (up to 18–25%) of nitrites, and (c) additional input of phosphates into solution, presumably from pore waters of the surface layer of bottom sediments in amounts 1.5–3 times greater than those removed with river runoff. A distinctive feature of barium migration is an additional input into solution (up to 20%) at the initial stage of salinization owing to the desorption from terrigenous material. The coagulation and flocculation of organic and organo-mineral colloids lead to the removal of significant part (up to 25–100%) of dissolved manganese, iron, aluminum, and rare-earth elements runoff, as well as to the removal of lead, titanium, zirconium, and hafnium from solution in amounts 1.1–6 times greater than their contents in the river water mass.

中文翻译：

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乌拉尔河口溶解物质径流的转化

基于2016-2017年的自然观测数据，研究了乌拉尔河和北里海水域混合带中溶解的主要和微量元素的分布。大多数主要离子（Na、K、Mg、SO4）和一些微量元素（Li、Rb、Cs、Sr、Co、Ni、Cu、Zn、Sb、Ga、Y、U、B、F）都建立了保守行为, Cr, Ge, Mo, W) 及其浓度与不同年份氯化物含量之间关系的共同参数。碳酸盐系统组分的分布受口滩处碳酸钙的化学沉淀控制。这个过程导致从溶液中去除了由河流径流携带的高达 11-17% 的钙和 6-8% 的碳氢化合物，并同时降低了 pH 值。营养素参与生物同化和再生的过程。乌拉尔河和里海水域混合带的特点是：(a) 浮游植物消耗大量的硅和硝酸盐（分别高达河流水域中含量的 58-88% 和 61-67%），（b ) 去除大部分（高达 18-25%）的亚硝酸盐，以及 (c) 向溶液中额外输入磷酸盐，大概是从底部沉积物表层的孔隙水中，其数量是用河流去除的数量的 1.5-3 倍径流。钡迁移的一个显着特征是在盐化的初始阶段由于陆源物质的解吸而额外输入到溶液中（高达 20%）。有机和有机矿物胶体的混凝和絮凝导致去除大部分（高达 25-100%）溶解的锰、铁、铝和稀土元素径流，