The behavior and impact of trace metals discharged into rivers depend on their solid/liquid fractionation and the fate of these two phases according to hydro-sedimentary processes. The solid/liquid fractionation depends on many environmental factors which imply uncertainties of several orders of magnitude in the evaluation of the partition coefficients, whether by geochemical modelling, in situ measurements or sorption-desorption experiments. In this context, this paper presents a model of solid/liquid fractionation of trace metals with suspended sediments in rivers which integrates the hydro-sedimentary conditions and the properties of the watershed. Its comparison with the ¹³⁷Cs concentrations measured in the Rhône River (France) thanks to monitoring shows that the solid/liquid fractionation of ¹³⁷Cs with suspended sediments in rivers depends on chemical processes but also and above all on variations in water flow rate, size and load of suspended sediments and the balance between anthropogenic discharges and the average trace metal content of soils in the watershed.

排放到河流中的痕量金属的行为和影响取决于它们的固/液分馏以及这两个阶段根据水沉积过程的命运。固/液分馏取决于许多环境因素，这意味着在评估分配系数时存在几个数量级的不确定性，无论是通过地球化学建模、原位测量还是吸附-解吸实验。在此背景下，本文提出了河流中含有悬浮沉积物的痕量金属的固/液分馏模型，该模型结合了水沉积条件和流域的特性。由于监测，它与在罗纳河（法国）测量的¹³⁷ Cs 浓度的比较表明，河流中悬浮沉积物的¹³⁷ Cs 取决于化学过程，但最重要的是取决于水流​​量、悬浮沉积物的大小和负荷的变化，以及人为排放与流域土壤中平均痕量金属含量之间的平衡。