LNAPL DISSOLUITON IN AQUEOUS LIQUID: LABORATORY COLUMN
EVALUATION AND NUMERICAL SIMULATION
1,2
Dongping Dai, 1Tissa H. Illangasekare, and 2,3John Ewing
1
Environmental Science and Engineering Division, Colorado School of Mines, Coolbaugh
Hall, 14th and Illinois St., Golden, CO 80401; 2Duke Engineering & Services, 9111
Research Blvd Austin, TX 78758; 1Phone: (303) 384-2126, 1E-mail: tillanga@mines.edu;
2
Phone: (303) 384-2237, 2E-mail: ddai@mines.edu; 3Phone: (512) 425-2065, 3E-mail:
jeewing@dukeengineering.com.
Understanding of the fate and transport of nonaqueous-phase liquid (NAPL) and
dissolved NAPL constituents, such as BTEX, is important in design and implementation of
NAPL-contaminated site cleanup. This laboratory column study is designed to better
understand dissolution of BTEX from the LANPL at low saturation into water at onedimension, and scale up to the larger scale with numerical simulation.
Soil cores and LNAPL from an LNAPL-contaminated site were used in the column
test. Segments of the core were packed into columns in eight, 3-inch sections, each column
section facility with ports for both sampling and monometer. This design made possible
evaluating dissolution at a range of sample lengths during one column test. The residual
LANPL saturations of the columns were estimated with a partitioning tracer technique at
the beginning of the dissolution process for each column section, as well as the entire
column.
From the scan of the dissolved hydrocarbons, primarily BTEX over time, the
relationship between NAPL saturation, aqueous-phase velocity, length-of-dissolution path,
and dissolution rate were determined. This correlation provides critical input for a
numerical model (UTCHEM) to simulate the dissolution in one dimension, and coupled
with scale relationships developed numerically, the mass transfer correlation of large
systems are predicated.
Key words: dissolution, saturation, transport, dimension, simulation