Combinatorial model of solute transport in porous media

INTRODUCTION In recent years, modeling of solute transport inporous media remains a key issue in the area of soilphysics and hydrogeology, because anthropogenicchemicals frequently enter the soil, subsoil andaquifers, either by accident or by accepted man-agement practices, and the resulting chemicalresidues pose hazards to the environment. The movement of solute in porous media iscommonly described by the convection-dispersionequation (CDE) (Bear, 1972) developed and ex-tens…

Combinatorial model of solute transport in porous media

Modeling of solute transport is a key issue in the area of soil physics and hydrogeology. The most common approach (the convection-dispersion equation) considers an average convection flow rate and Fickian-like dispersion. Here, we propose a solute transport model in porous media of continuously expanding scale, according to the combinatorics principle. The model supposed actual porous media as a combinative body of many basic segments. First, we studied the solute transport process in each basic segment body, and then deduced the distribution of pore velocity in each basic segment body by difference approximation, finally assembled the solute transport process of each basic segment body into one of the combinative body. The simulation result coincided with the solute transport process observed in test. The model provides useful insight into the solute transport process of the non-Fickian dispersion in continuously expanding scale.