Simulating solute transport in an aggregated soil with the dual-porosity model: measured and optimized parameter values

Abstract

The capability of the first-order, dual-porosity model, which explicitly accounts for non-ideal transport caused by the presence of 'immobile' water, to predict the non-ideal transport of nonsorbing solute in a constructed aggregated soil has been investigated. Miscible-displacement experiments performed with a well-characterized aggregated soil and a non-reactive tracer (pentafluorobenzoate) served as the source of the data. Values for the input parameters associated with physical non-equilibrium were determined independently and compared with values obtained by curve fitting of the experimental measurements. The calculated and optimized values compared well, suggesting that the non-equilibrium parameters represent actual physical phenomena.

Time and space nonlocalities underlying fractional-derivative models: Distinction and literature review of field applications

“…Five alternative, nonlocal transport techniques have been developed for the use of the general hydrology community. These techniques are the Stochastic Averaging of the classical ADE (SA-ADE) method, the (single-and) multiple-rate mass transfer (MRMT) method (see the recent work [64,65,68,69], also see [25,26,30,60,67,109,134,138,149,154], among many others), the continuous time random walk (CTRW) method [18,47,48,108], the time fractional advection-dispersion equation (fADE) method (with the time scale index 0 < c < 1) [8,97,128,147], and the space fADE method [11][12][13]29,129,148]. These alternative conceptual models describe nonlocal dependence on either time or space, or both, to explain the development of anomalous dispersion.…”

Comparison of alternative models for simulating anomalous solute transport in a large heterogeneous soil column

“…There are a few methods developed to determine the mobile water fraction and mass transfer coefficient in MIM. For example, Brusseau et al (1994) used the gravimetrical mass balance method to measure the mobile water fraction and determined mass transfer coefficient in an aggregated soil in terms of Fick's law. In addition, these two parameters can be determined by experimental methods such as tension disk infiltrometer (Casey et al, 1999), point-source method (Al-Jabri et al, 2002), and time domain reflectometry (TDR) method (Lee et al, 2000).…”

“…As pointed out by Griffioen et al (1998), a major attribute of MIM is that it characterizes, in simple mathematical forms, the observed anomalous BTCs and the influence of soil's heterogeneous structure on transport process. It has been shown that the MIM can successfully describe solute transport in homogeneous repacked soil (Bond and Wierenga, 1990;Padilla et al, 1999;Toride et al, 2003), aggregated soil (van Genuchten and Wierenga, 1977;Nkedi-Kizza et al, 1983;Brusseau et al, 1994), undisturbed field soil cores (Smettem, 1984), and locally stratified soil (Herr et al, 1989;Li et al, 1994). Jury (1982) and Jury and Roth (1990) applied the concept of a transfer function to model solute transport in complex soil systems.…”

Final Technical Report - Integrated Hydrogeophysical and Hydrogeologic Driven Parameter Upscaling for Dual-Domain Transport Modeling

“…Binary and bi-modal variations suggest a natural partitioning of the total domain into mobile and immobile porosity regions (Brusseau et al 1994). For more continuous heterogeneity, the proper partitioning is not obvious, but a case study suggested regions with hydraulic conductivity greater than the effective value might correspond to the mobile domain .…”

“…However, use of dualdomain models in a general predictive manner has been a difficult and persistent challenge (Brusseau et al 1994;Griffioen et al 1998;Maraqa 2001;Guswa and Fryberg 2002;Willman et al 2008), particularly at field-scale where characterization of permeability and flow is inherently limited (Bibby 1981;Painter et al 2001;. To make predictions in the absence of site-specific tracer data, one would like to relate dual-domain parameter values to aquifer attributes in an optimal manner.…”