MODELING AND EXPERIMENTAL INVESTIGATION ELF TRANSIENT, NONEQUILIBRIUMMASS-TRANSFER DURING STEAM STRIPPING OF A NONAQUEOUS PHASE LIQUID IN UNSATURATED POROUS-MEDIA
Agj. Vanderham et Hjh. Brouwers, MODELING AND EXPERIMENTAL INVESTIGATION ELF TRANSIENT, NONEQUILIBRIUMMASS-TRANSFER DURING STEAM STRIPPING OF A NONAQUEOUS PHASE LIQUID IN UNSATURATED POROUS-MEDIA, Water resources research, 34(1), 1998, pp. 47-54
The present paper addresses the one-dimensional unsteady process of st
eam stripping of the unsaturated zone of soils contaminated with nonaq
ueous phase liquids (NAPLs). First, the volatilization mechanism and t
he transport by steam are considered, taking the view that nonequilibr
ium exists between liquid and vapor phases; second, the effect of evap
oration on the specific area is taken into account. The governing equa
tions are rendered dimensionless and solved in closed form. For variou
s dimensionless numbers, solutions are presented, showing the role of
the prevailing physical phenomena. Experiments have been performed usi
ng two sand mixtures with water and NAPL saturations ranging from 24%
to 44% and from 3.8% to 9.4%, respectively. The experimental results c
onfirm the applicability of the theoretical model presented. Furthermo
re, the analysis results in an empirical correlation for the Sherwood
number valid for a broad range of Peclet numbers (2 < Pe < 60).