Abstract

In the underground media there exist two types of solute transportation: first, this happen in the channels by the flowing fluid which carries solute (Advection), second it happen in the interface of rock and channel by diffusion of solute (Diffusion). Then it is obvious that diffusion and dispersion are important mechanisms for solute transport in porous media. It has been found that diffusion coefficient in field-scale is different from those values that exist in the lab-scale for the same geologic site core samples therefore an equivalent diffusion and dispersion coefficient must be used for field scale calculations, De. In addition, the surveyed data indicate that field-scale longitudinal dispersivity generally increases with observation scale, which is consistent with previous studies (Zhou et al 2007). In this research we want to determine analytical solutions for molecular diffusion of a component in porous media and using the analytical solutions to model the heterogeneity effect and finally integrating the analytical solutions to find the appropriate diffusion coefficient associated with field-scale studies.