U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings
of the Technical Meeting, Colorado Springs, Colorado, September 20-24, 1993,
Water-Resources Investigations Report 94-4015
Simulation of Trichloroethylene Volatilization in the Unsaturated
Zone during a Field Infiltration Experiment at Picatinny Arsenal, New Jersey
by
H. Jean Cho (Department of Civil and Environmental Engineering,
Vanderbilt University, Box 1658-B, Nashville, TN 37235), James A. Smith
(Department of Civil Engineering, University of Virginia, Thornton Hall,
Charlottesville, VA 22903--2442), and Peter R. Jaffé (Department
of Civil Engineering and Operations Research, Princeton University, Princeton,
NJ 08544)
Abstract
A field experiment was conducted at Picatinny Arsenal, New Jersey, to
study the dynamics of trichloroethylene as it volatilizes from contaminated
ground water to land surface during infiltration. It was found that the
gas- and water-phase concentrations of TCE were not in equilibrium in the
unsaturated zone during infiltration. A mathematical model was developed
to simulate the volatilization of TCE in the unsaturated zone. Gas--water
mass-transfer-rate constants were calibrated to the data. The mass-transfer
limitations of a volatile organic compound between the gas and liquid phases
were described explicitly in the model. The water-infiltration rate was
0.34 centimeters per hour, and TCE desorption from the soil matrix was significant.
Slow desorption of TCE from the soil matrix was incorporated in the mathematical
model.
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