Centrifuge Modeling of Cadmium Migration in Saturated and Unsaturated Soils
Centrifuge Modeling of Cadmium Migration in Saturated and Unsaturated Soils
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DOI：
10.1080/15320380500180440
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发表时间：
2005-09
期刊：
影响因子：
--
通讯作者：
I. Lo;Jianhong Zhang;Liming Hu
中科院分区：
文献类型：
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作者：
I. Lo;Jianhong Zhang;Liming Hu
近年来，研究人员逐渐认识到，土工离心机可以为研究无机污染物在土壤中的流动和迁移提供一个强大的实验工具。在大多数离心机模型中，通常使用惰性、非吸附的无机化合物(如钠离子)而不是吸附的重金属作为化学物质来研究污染物的传输行为。为了克服这种方法的缺点，设计了一种用于研究污染物在饱和和非饱和土壤中一维迁移的离心机试验，该试验使用了一种吸附污染物(即镉)，并在两个离心机加速下进行。研究了土壤中吸附Cd的浓度沿土壤深度的分布、土壤含水率随土壤深度的变化以及Cd在土壤中的运移行为。离心机结果表明，15g和20g离心机模型的镉浓度分布相似，非饱和土壤中水分的一维运动是可以重现的。吸附污染物的离心机模型的有效性可能会受到g水平的影响，而g水平又决定了离心机测试时间并影响了吸附平衡。
Researchers recently have come to recognize that geotechnical centrifuge can provide a powerful experimental tool for investigating the flow and transport of inorganic contaminants in soils. Inert, non-adsorptive inorganic compounds (e.g., sodium ions) rather than adsorptive heavy metals are often used as the chemical for the investigation of pollutant transport behavior in most centrifuge modeling. To overcome the shortcomings of this approach, centrifuge tests for the study of one-dimensional pollutant migration in both saturated and unsaturated soils were designed using an adsorptive pollutant (i.e., cadmium) and conducted at two centrifugal accelerations. In this study, the concentration profile of adsorptive cadmium along the depth of soil, the moisture content varying with the soil depth and the transport behavior of the cadmium in soils were investigated. The centrifuge results show that the cadmium concentration profiles are found to be similar for the centrifuge models performed at 15 g and 20 g and the one-dimensional moisture movement in the unsaturated soil can be reproducible. The validity of centrifuge modeling of adsorptive pollutants might be affected by the g-level that, in turn, determines the centrifuge testing time and affects the sorption equilibrium.