An analytical model for nonlinear adsorptive transport through layered soils

Wu, Yu‐Shu; Kool, J. B.; Huyakorn, Peter S.; Saleem, Z. A.

doi:10.1029/96wr02716

Cited by 20 publications

(5 citation statements)

References 12 publications

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“…Analytical studies have already been done in field of diffusion or convection of gas and solute in layered soil [4,5,9,30,55,53,31,32]. Analytical approximation [4,5,9,53], Laplace transform [30,55] or integral transform pair technique [31,32] were used to solve diffusion or dispersion in the layered porous medium with the constant diffusion coefficient D(x) or dispersion coefficient and the retardation factor R(x) within each layer. Since constant D(x) within each layer is not a good approximation for describing the real layered system (Fig.…”

Section: Theorymentioning

confidence: 99%

Analytical modeling of one-dimensional diffusion in layered systems with position-dependent diffusion coefficients

Liu

Cheng

2008

Advances in Water Resources

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Section: Theorymentioning

confidence: 99%

Analytical modeling of one-dimensional diffusion in layered systems with position-dependent diffusion coefficients

Liu

Cheng

2008

Advances in Water Resources

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“…Analytical approximation , Laplace transform , , or integral transform pair technique , has been used to treat the diffusion or convection of gas and solute in layered porous media. Since the inverse Laplace transformation of an N -layer system and the integral transform pair technique with N > 2 are difficult ,, , we use a special and simplified integral transform technique, the orthogonal expansion technique − .…”

Section: Theorymentioning

confidence: 99%

Unified Multilayer Diffusion Model and Application to Diffusion Experiment in Porous Media by Method of Chambers

Liu

Barbour

Cheng

2009

Environ. Sci. Technol.

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Diffusion coefficient is an important parameter for examining contaminant transport in the environment. Chamber methods (with or without external mixing devices) are the most popular methods for measuring effective diffusion coefficients in porous media (Deff) through air or water. The objectives of this paper were to apply simplified and unified analytical methods for both perfectly mixed and nonmixed (one- or two-) chamber systems and to examine how mixing affects the estimation of Deff. An analytical solution for a multilayer transient diffusion model was applied to the chamber methods without external mixing. By increasing the diffusion coefficient in reservoirs (D1 and D3) more than 10 times from the value for air or water (D0), the model was sufficient to approximate the well-mixed condition and, consequently, can be used to model transient diffusion in chamber systems with external mixing devices. We demonstrated that at long time Deff was related to the first eigenvalue (beta1) of a transcendental equation, which provided a quick method for determining Deff accurately from experimental data. The error caused by using the well-mixed approximation can be significant for a single-chamber system when there are no external mixing devices. This error increased rapidly with decreases in the experimental duration. A good fit for the concentration versus time curve could not be obtained forthe well-mixed solution, especially when sampling ports were near the boundary (x=0) and interface (x = l1). The proposed solutions are useful when the reservoir or chamber methods are used for measuring Deff and have wide applications in predicting contaminates transport in porous media and groundwater.

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“…Transport of dissolved solutes in soils is commonly described by the advection-dispersion equation. Analytical solutions have been derived for a variety of boundary and initial conditions (Starr and Parlange, 1976;Barry and Sposito, 1989;Aral, 1992a, 1992b;Segol, 1993;Toride, 1995, 1998;Wu et al, 1997). Although these solutions are obtained for narrowly defined conditions, they have many applications such as the verification of computer codes, prediction of solute movement for large times or distances where the use of numerical models become impractical, and the determination of transport parameters from soil column studies.…”

Section: Solute Transport Modelsmentioning

confidence: 99%

Modeling Flow and Transport in Unsaturated Porous Media: A Review

Al-Barwani

Al‐Lawatia

Balakrishnan

et al. 2000

SQU Journal for Science

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Underground water is a vital natural resource and every effort should be made to understand ways and means of efficiently using and managing it. The unsaturated zone, bounded at its top by the land surface and below by the water table, is the region through which water, together with pollutant carried by the water, infiltrates to reach the groundwater. Therefore, various processes occurring within the unsaturated zone play a major role in determining both the quality and quantity of water recharging into the groundwater. Classical methods of predicting water flow and contaminant transport processes in unsaturated porous media are generally inadequate when applied to natural soils under field conditions, due to the occurrence of macropores, structured elements and spatial variability of soil properties. Contaminant transport models also require the simultaneous solution of the unsaturated flow and transport equations. For applications to field conditions, numerical solutions and computer simulations based on numerical models have been increasingly used. Advances and progress in modeling water flow and contaminant transport in the unsaturated zones are reviewed, and specific research areas in need of future investigation especially relevant to Oman are outlined.

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An analytical model for nonlinear adsorptive transport through layered soils

Cited by 20 publications

References 12 publications

Analytical modeling of one-dimensional diffusion in layered systems with position-dependent diffusion coefficients

Analytical modeling of one-dimensional diffusion in layered systems with position-dependent diffusion coefficients

Unified Multilayer Diffusion Model and Application to Diffusion Experiment in Porous Media by Method of Chambers

Modeling Flow and Transport in Unsaturated Porous Media: A Review

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