Understanding solute transport through macroscopic interfaces is essential to understand the effects of geological heterogeneity on contaminant transport in porous media. Studies of solute transport in compartmental porous media have noted the asymmetry of breakthroughs (BTCs) in solute movement across material interfaces, indicating the presence of discontinuous concentration that makes solute transport directionally dependent. Transition interfaces are more common in nature than sharp interfaces. To understand solute transport across transition interfaces, well-controlled laboratory experiments were performed. A numerical model was also built to understand mass accumulation and concentration discontinuity through transition as well as sharp interfaces. We conclude that directionally dependent asymmetry of BTCs was found with both sharp and transition interfaces. The asymmetry of BTCs was more pronounced at a transition interface than at a sharp interface. The mobile and immobile (MIM) model can better capture the directionally dependent transport of solutes through a sharp/transition interface than the advection-dispersion equation (ADE). The mobile water partition coefficient (β) and mass transfer coefficient (ω) in MIM were lager in the direction from fine sand to coarse sand (F-C). The time difference between tracer replace and tracer input is greater in the presence of an interface, especially transition interfaces. Even at small Reynolds numbers (1 × 10⁻⁴ to 0.116), solute transport across a discontinuous interface under reversible flow directions is most likely dominated by convective dispersion rather than an assumed diffusion process.

了解通过宏观界面的溶质迁移对于了解地质异质性对多孔介质中污染物迁移的影响至关重要。对隔室多孔介质中溶质传输的研究已经注意到跨材料界面的溶质运动中突破 (BTC) 的不对称性，这表明存在使溶质传输定向依赖的不连续浓度。过渡界面在本质上比尖锐界面更常见。为了了解跨过渡界面的溶质转运，进行了控制良好的实验室实验。还建立了一个数值模型来了解通过过渡和尖锐界面的质量积累和浓度不连续性。我们得出结论，在尖锐和过渡界面中都发现了 BTC 的方向相关不对称性。BTC 的不对称性在过渡界面处比在尖锐界面处更明显。与平流-弥散方程 (ADE) 相比，移动和固定 (MIM) 模型可以更好地捕捉溶质通过尖锐/过渡界面的方向相关传输。流动水分配系数（MIM 中的β ) 和传质系数 ( ω ) 在从细砂到粗砂 (FC) 的方向上较大。在存在接口的情况下，跟踪器替换和跟踪器输入之间的时间差更大，尤其是转换接口。即使在小的雷诺数（1 × 10 ^-4到 0.116）下，在可逆流动方向下通过不连续界面的溶质传输很可能由对流分散而不是假定的扩散过程支配。