Analytical and semi-analytical solutions of four steady-state flow and transport problems, pertinent to migration of single-component volatile liquids in homogeneous unsaturated subsurface media, are derived. Attention is concentrated mainly on the interaction of the liquid's flow and organic vapor transport processes in the upper part of a dry soil. Applications of the solutions to several examples, associated with soil contamination by benzene, illustrate the impact of volatility on the downward penetration of the liquid into the soil, its areal spread and capillary-rise above an impermeable layer. Results of this study indicate that the interaction between infiltration of the volatile liquid and transport of its vapors may be significant for relatively low fluxes only (<10-4-10-2 m day-1). Volatility of the liquid significantly reduces its areal spread above the impermeable horizontal lower boundary located relatively close to the open ground surface (<1-10 m). It may also lead to a reduction in the capillary rise of the liquid residing in the soil, especially in coarse-textured soils.
Theoretical analysis of the impact of vapor transport on the NAPL distribution in dry soils
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Theoretical analysis of the impact of vapor transport on the NAPL distribution in dry soils
Analytical and semi-analytical solutions of four steady-state flow and transport problems, pertinent to migration of single-component volatile liquids in homogeneous unsaturated subsurface media, are derived. Attention is concentrated mainly on the interaction of the liquid's flow and organic vapor transport processes in the upper part of a dry soil. Applications of the solutions to several examples, associated with soil contamination by benzene, illustrate the impact of volatility on the downward penetration of the liquid into the soil, its areal spread and capillary-rise above an impermeable layer. Results of this study indicate that the interaction between infiltration of the volatile liquid and transport of its vapors may be significant for relatively low fluxes only (<10-4-10-2 m day-1). Volatility of the liquid significantly reduces its areal spread above the impermeable horizontal lower boundary located relatively close to the open ground surface (<1-10 m). It may also lead to a reduction in the capillary rise of the liquid residing in the soil, especially in coarse-textured soils.