Translator Disclaimer
13 December 2016 An exponential boundary-layer solution to the convection–dispersion equation of solute transport in soils
Author Affiliations +
Abstract

The dispersion coefficient (D) and retardation factor (R) are key parameters in convection–dispersion equation (CDE). The boundary-layer theory provides a simple and convenient method to solve the CDE for a third-type boundary condition under steady water flow. However, the present boundary-layer solutions cannot accurately describe the solute concentration at higher average pore-water velocities for a long-period solute transport process. In this study, an improved exponential solution to the CDE was developed using boundary-layer theory with the assumption that the resident solute concentration in soil was an exponential function related to the position under steady water flow. The accuracies of three boundary-layer solutions (parabolic polynomial, cubic polynomial, and exponential) were evaluated by comparing with the exact solution in concentration predictions for a third-type boundary condition under steady water flow. The solute concentration distributions calculated from the three boundary-layer solutions were close to those from the exact solution. At higher average pore-water velocities, the exponential solution was better than the polynomial solutions in D and R estimations. Moreover, the feasibility of the three boundary-layer solutions was verified using a column experiment. This study provides an effective way for estimating D and R in laboratory or field studies.

Copyright remains with the author(s) or their institution(s). Permission for reuse (free in most cases) can be obtained from RightsLink.
Shuai Tan, Quanjiu Wang, and Beibei Zhou "An exponential boundary-layer solution to the convection–dispersion equation of solute transport in soils," Canadian Journal of Soil Science 97(2), 200-214, (13 December 2016). https://doi.org/10.1139/cjss-2016-0037
Received: 1 April 2016; Accepted: 1 November 2016; Published: 13 December 2016
JOURNAL ARTICLE
15 PAGES


SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top