Application of continuous time random walks to transport in porous media

The behavior of chemical species as they migrate through heterogeneous poro us media is considered. The so-called "anomalous'' transport patterns frequ ently measured in these materials are quantified in the framework of a cont inuous time random walk (CTRW) formalism. The physical basis for applicatio n of the CTRW is discussed, and new solutions for the first passage time di stribution are presented to covet the entire range of transport behaviors. Application of these solutions to analysis of experimental data is also dis cussed.