Two-dimensional laboratory simulation of LNAPL infiltration and redistribution in the vadose zone.
J Contam Hydrol
; 76(3-4): 211-33, 2005 Feb.
Article
en En
| MEDLINE
| ID: mdl-15683881
ABSTRACT
A quantitative two-dimensional laboratory experiment was conducted to investigate the immiscible flow of a light non-aqueous phase liquid (LNAPL) in the vadose zone. An image analysis technique was used to determine the two-dimensional saturation distribution of LNAPL, water and air during LNAPL infiltration and redistribution. Vertical water saturation variations were also continuously monitored with miniature resistivity probes. LNAPL and water pressures were measured using hydrophobic and hydrophilic tensiometers. This study is limited to homogeneous geological conditions, but the unique experimental methods developed will be used to examine more complex systems. The pressure measurements and the quantification of the saturation distribution of all the fluids in the entire flow domain under transient conditions provide quantitative data essential for testing the predictive capability of numerical models. The data are used to examine the adequacy of the constitutive pressure-saturation relations that are used in multiphase flow models. The results indicate that refinement of these commonly used hydraulic relations is needed for accurate model prediction. It is noted in particular that, in three-fluid phase systems, models should account for the existence of a residual NAPL saturation occurring after NAPL drainage. This is of notable importance because residual NAPL can act as a non negligible persistent source of contamination.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Solventes
/
Contaminantes del Agua
/
Agua
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
J Contam Hydrol
Asunto de la revista:
TOXICOLOGIA
Año:
2005
Tipo del documento:
Article
País de afiliación:
Reino Unido