On the ability of the Generalized Continuum Transport Model to properly capture dispersion

Abstract

Abstract The ability of the Generalized Continuum Transport model to describe dispersion is studied through the comparison of the breakthrough curves with an analytical solution of the linear advection-dispersion Equation. First, a velocity distribution due to Taylor dispersion in a capillary tube is related to the dispersion coeficient of the advection-dispersion equation. The same distribution is applied to the Generalized Continuum Transport model, where the dispersive flux term is not included as the term proportional to the concentration gradient. In the second stage the velocity distribution is obtained from the transition probability introduced through the Continuous Time Random Walk approach. The approaches support the idea that the Generalized Continuum Transport model captures velocity variations naturally through the parameter space. The results confirm that a proper selection of the parameter space, including its size, leads to more physical transport description as well as accurate quantification.