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
Surfactant-Enhanced Remediation of Ground Water at Picatinny
Arsenal, New Jersey
James J. Deitsch (Department of Civil Engineering and Applied
Mechanics, University of Virginia, Charlottesville, Virginia 22903-2442)
and James A. Smith (Department of Civil Engineering and Applied Mechanics,
University of Virginia, Charlottesville, Virginia 22903-2442)
The efficiency of pump-and-treat remedial systems is limited by the slow,
kinetic mass transfer of organic contaminants from soil to water. The scope
of this research is to determine whether the addition of the nonionic surfactant,
Triton X-100, to the aqueous phase can artificially increase the rate of
trichloroethene (TCE) mass transfer from soil to water at Picatinny Arsenal.
The rate of TCE mass transfer (desorption) from soil to water is modeled
as the product of a mass-transfer coefficient and a concentration gradient.
Laboratory experiments were conducted using continuous-flow stirred tank
reactors (CFSTR's), with and without Triton X-100, to study the effect of
the surfactant on the rate of desorption of TCE from soil to water. Preliminary
results indicate that the rate of desorption is increased by the presence
of Triton X-100 in the aqueous phase. Two possible mechanisms are responsible
for the increased desorption rate: First, the addition of Triton X-100 above
its critical micelle concentration can increase the apparent water solubility
of TCE and thus increase the concentration gradient between the sorbed and
aqueous phases. Second, Triton X-100 can increase the mass-transfer coefficient.
Future experiments are planned to determine the precise mechanism affecting
the rate of desorption.