Migration of Benzene as Light non-aqueousPhase in the Stratified Soil under Unsaturated Condition

Abstract

A COMSOL Multiphysics software depended on finite element numerical solution is used for prediction the spatially and temporally propagation of the benzene front as non-aqueous phase liquid through the stratified soil consisted of clay and Kerbala’s sand as domain (1.3*2) m. The variation of many parameters such as capillary pressure, benzenedistribution, trans missive properties of the soil.Thedegree of saturation as a function of capillary pressure and relative permeability during unsaturated conditions were determined. The results showed that the benzene front in the Kerbala’s sand with presence of clay retained a regular, circular shape at the initial stage of the spill, shortly after that it become ellipsoid as it was advancing. The maximum saturation occurred below the source of the contaminant during infiltration stage. All analysis showed that the presence of clay layer controls the vertical movement of NAPLs in heterogeneous porous medium.