ABSTRACT
Contaminants sorbed to “water-wet” soil’ particles or rock surface in either the unsaturated or saturated zone. Mobilization of sorbed contaminants can be accomplished by desorption into the aqueous phase in both saturated and unsaturated zones. Sorption of contaminants onto soil surfaces is generally treated by assuming equilibrium conditions between the sorbed and the solution phase. At equilibrium, the relationship between the sorbed and solution phase concentration can be described by the Freundlich isotherm. Immobilization can be accomplished by enhancing sorption. Contaminants adhering to the soil surface are already considered to be immobile. Sorption, however, is an effective mechanism for fixation since desorption into the mobile phase could continue for an extended period of time. Sorbed contaminants on soil surfaces in the unsaturated and the saturated zone can act as a source of contamination for an extended period of time.
