ABSTRACT
Contamination of soils, aquifers, and groundwater by organic nonaqueous phase liquid (NAPL) pollutants, that is, fossil fuels, chlorinated hydrocarbons, and other organic chemicals (e.g., polycyclic aromatic hydrocarbons, methyl tertiary butyl ether), constitutes a major environmental issue of concern worldwide [1-4]. The penetration of NAPLs into soil and groundwater is, in most cases, a result of accidents, improper codes of fuel handling and disposal, as well as the leakage of storage tanks and fuel conveying systems. The migration of NAPLs in the soil occurs via various mechanisms such as advection, dispersion/dissolution (in the aqueous medium within the porous soil matrix), and diffusion, resulting, ultimately, in accumulation of entrapped NAPLs as residual saturation in both the unsaturated and saturated zones of aquifers.
