Partitioning tracer tests are often used to quantify the amount of non-aque
ous phase liquid (NAPL) present in a porous medium. Results from such tests
are usually interpreted by using models that assume local equilibrium exis
ts between the NAPL and the aqueous phase or by using a moment method to so
lve for the fraction of the pore space occupied by the NAPL. We investigate
d the transport of partitioning alcohol tracers through heterogeneous sand
porous medium systems containing a stationary trichloroethylene (TCE) phase
for a range of aqueous phase velocities. NAPL saturations were quantified
using a non-destructive X-ray absorption methodology. Experimental results
were simulated using a numerical solution to an advective-dispersive model
in which mass transfer between the NAPL and the aqueous phase was approxima
ted using a dual-resistance approach consisting of a boundary layer mass tr
ansfer resistance and a diffusional resistance within the NAPL. The numeric
al model agreed well with the experimental data, and moment analysis yielde
d reasonable estimates of actual NAPL saturations. (C) 2000 Elsevier Scienc
e B.V. All rights reserved.