Pj. Vangeel et Jf. Sykes, LABORATORY AND MODEL SIMULATIONS OF A LNAPL SPILL IN A VARIABLY-SATURATED SAND .1. LABORATORY EXPERIMENT AND IMAGE-ANALYSIS TECHNIQUES, Journal of contaminant hydrology, 17(1), 1994, pp. 1-25
Citations number
31
Categorie Soggetti
Water Resources","Environmental Sciences","Geosciences, Interdisciplinary
A two-dimensional, multiphase flow experiment was conducted in the lab
oratory. The saturation distribution of a lighter than water non-aqueo
us-phase liquid (LNAPL) as it migrated through a variably-saturated sa
nd medium was determined using image analysis techniques. The pressure
s in the water and LNAPL phases were measured using hydrophilic and hy
drophobic porous cups connected to a series of pressure transducers an
d a data acquisition system, The LNAPL inflow and water outflow were a
lso recorded. A series of capillary pressure-saturation experiments we
re conducted for each two-phase system. The capillary pressures record
ed by the pressure transducers were used to calculate the phase satura
tions based on a fully hysteretic capillary pressure-saturation algori
thm. The static equilibrium capillary pressure-saturation relationship
s proved to be invalid immediately ahead of the LNAPL front. The capil
lary pressure-saturation relationship appeared to be dynamic for short
periods of time as the LNAPL front arrived at each transducer locatio
n. The presence of an entrapped air phase as the LNAPL migrated throug
h the unsaturated zone clearly affected the migration of the LNAPL and
the maximum LNAPL saturation reached in the sand medium.