The previous chapter focused on the physical mechanisms (advection, diffusion, and dispersion) and the physical characteristics of the subsurface (heterogeneity) that control the dynamics of contaminant transport from the land surface to the water table.
In addition, contaminants are subject to a range of chemical interactions with other (dissolved) chemical species present in the subsurface, colloids, and the porous matrix itself.
The previous sections of this dealt with such reactions, including sorption (by various types of bonding), decay, degradation, complexation, precipitation, dissolution, and volatilization as well as interactions (and transport) with migrating colloids.
These reactions thus influence—and are influenced by—advective, diffusive, and dispersive transport mechanisms.