Chapter 7.1.3. Sorption and Retardation

Electrical charges on the surface of fine grained soils are able to attract oppositely charged ionic species in solution (Chapters 2 and 3). Sorption is the process of adsorption or desorption resulting from these processes. As water with dissolved chemical species flows through unsaturated (or saturated) soil, species may be removed or added to the liquid phase by sorption.

The rate of adsorption to the solid mineral soil phase is