The aim of this paper is to assess the suitability of DGT to extract kinetic rates of desorption of cesium (Cs) from soils. For this purpose, laboratory experiments with a natural soil spiked with Cs were carried out under three different contamination conditions, reflecting either an increase in Cs contamination level or an ageing of the contamination within the soil. The experimental results, i.e. the Cs accumulation kinetics onto DGT probes were interpreted by the DGT-PROFS model. The latter calculates the partitioning of Cs between two particulate pools, describing weak and strong interactions respectively, as well as kinetic rates describing exchange reactions. Experimental conditions did not show any major impact on desorption rates, suggesting that desorption kinetics were not significantly affected by contamination level and ageing. Instead, the distribution of Cs among weak and strong sites was shown to be the predominant factor governing the differences observed in the remobilization of Cs to porewater among experimental conditions. The DGT technique combined with the DGT-PROFS modelling approach was proved to be efficient in estimating desorption kinetic rates of Cs in soils.

本文的目的是评估DGT提取土壤中铯（Cs）解吸动力学速率的适用性。为此，在三种不同的污染条件下对掺有Cs的天然土壤进行了实验室实验，这反映了Cs污染水平的提高或土壤中污染物的老化。DGT-PROFS模型解释了实验结果，即Cs在DGT探针上的蓄积动力学。后者计算Cs在两个颗粒池之间的分配，分别描述了弱相互作用和强相互作用，以及描述交换反应的动力学速率。实验条件没有显示出对解吸速率有任何重大影响，表明解吸动力学不受污染水平和老化的影响很大。取而代之的是，Cs在弱点和强点之间的分布被证明是控制实验条件下将Cs迁移到孔隙水中的差异的主要因素。事实证明，DGT技术与DGT-PROFS建模方法相结合可有效估算土壤中Cs的解吸动力学速率。