Brusseau M L, Difilippo E L, Marble J C, Oostrom M
Hydrology and Water Resources, University of Arizona, J.W. Harshbarger Building, Tucson, AZ 85721, United States.
Chemosphere. 2008 Apr;71(8):1511-21. doi: 10.1016/j.chemosphere.2007.11.064. Epub 2008 Feb 14.
A series of flow-cell experiments was conducted to investigate aqueous dissolution and mass-removal behavior for systems wherein immiscible liquid was non-uniformly distributed in physically heterogeneous source zones. The study focused specifically on characterizing the relationship between mass flux reduction and mass removal for systems for which immiscible liquid is poorly accessible to flowing water. Two idealized scenarios were examined, one wherein immiscible liquid at residual saturation exists within a lower-permeability unit residing in a higher-permeability matrix, and one wherein immiscible liquid at higher saturation (a pool) exists within a higher-permeability unit adjacent to a lower-permeability unit. The results showed that significant reductions in mass flux occurred at relatively moderate mass-removal fractions for all systems. Conversely, minimal mass flux reduction occurred until a relatively large fraction of mass (>80%) was removed for the control experiment, which was designed to exhibit ideal mass removal. In general, mass flux reduction was observed to follow an approximately one-to-one relationship with mass removal. Two methods for estimating mass-flux-reduction/mass-removal behavior, one based on system-indicator parameters (ganglia-to-pool ratio) and the other a simple mass-removal function, were used to evaluate the measured data. The results of this study illustrate the impact of poorly accessible immiscible liquid on mass-removal and mass-flux processes, and the difficulties posed for estimating mass-flux-reduction/mass-removal behavior.
进行了一系列流动池实验，以研究在不混溶液体在物理非均相源区中分布不均匀的系统中的水溶解和质量去除行为。该研究特别关注表征对于流动水难以接触到不混溶液体的系统，质量通量降低与质量去除之间的关系。研究了两种理想化的情况，一种是残余饱和度的不混溶液体存在于高渗透率基质中的低渗透率单元内，另一种是高饱和度的不混溶液体（一个液池）存在于与低渗透率单元相邻的高渗透率单元内。结果表明，对于所有系统，在相对适中的质量去除分数时质量通量都出现了显著降低。相反，对于旨在展示理想质量去除的对照实验，直到去除相对较大比例的质量（>80%）时才出现最小的质量通量降低。一般来说，观察到质量通量降低与质量去除大致呈一对一的关系。使用两种估计质量通量降低/质量去除行为的方法，一种基于系统指标参数（节状液-液池比），另一种是简单的质量去除函数，来评估测量数据。本研究结果说明了难以接触到的不混溶液体对质量去除和质量通量过程的影响，以及估计质量通量降低/质量去除行为所面临的困难。
