Dispersion in heterogeneous porous media: One-equation non-equilibrium model

In this paper, the method of large-scale averaging is used to develop two d ifferent one-equation models describing dispersion in heterogeneous porous media. The first model represents the case of large-scale mass equilibrium, while the second represents the asymptotic behavior of a two-equation mode l obtained by large-scale averaging. It is shown that a one-equation, non-e quilibrium model can be developed even when the intrinsic large-scale avera ged concentrations for each region are not equal. The solution of this non- equilibrium model is equivalent to the asymptotic behavior of the two-equat ion model.