HR: 0800h
AN: H31B-0371    [Abstracts]
TI: Movement and Remediation of a Volatile, Multicomponent DNAPL in a Variably-Saturated, Heterogeneous Porous Medium
AU: * Oostrom, M
EM: mart.oostrom@pnl.gov
AF: Hydrology Group, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99354 United States
AU: Dane, J H
EM: danejac@auburn.edu
AF: Department of Agronomy and Soils, Auburn University, Auburn, AL 36849-5412 United States
AU: Wietsma, T W
EM: wietsma@pnl.gov
AF: Environmental Molecular Scienes Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354 United States
AB: An intermediate-scale flow cell experiment was conducted to study the behavior of a multicomponent DNAPL at structural interfaces and subsequent remediation using two different forms of the soil vapor extraction (SVE) technique. The flow cell (100-cm long, 5-cm wide, and 80 cm high), was packed under saturated conditions with sloped layers of Hanford silt and coarse sand, embedded in a matrix of a medium-grained laboratory sand. After packing, the water table was lowered to 2 cm above the bottom of the flow cell to establish variably saturated conditions. A finite amount of a volatile multicomponent DNAPL, mimicking the organic liquid disposed at the Hanford Site, was then injected from a small source zone. The infiltration and redistribution processes were visually recorded. In addition, a dual-energy gamma radiation system was used to determine DNAPL and water saturation at more than 1000 locations. Results indicate that lateral spreading of the DNAPL is greatly enhanced by the heterogeneities. The silt layers, by virtue of their substantial non-wetting fluid entry pressures and high water saturations, completely diverted the DNAPL laterally. The relatively dry coarse-sand layers forced some of the DNAPL to move laterally but also allowed some infiltration.
DE: 1829 Groundwater hydrology
DE: 1831 Groundwater quality
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting