DNAPL-Water Interfacial Area Determinations During Entrapped DNAPL Dissolution Using Tracer Techniques
EMSL Project ID
25393
Abstract
The release of dense nonaqueous-phase liquids (DNAPL) into soils and aquifers is a widespread and serious environmental problem. Due to the typically low solubility, DNAPL may act as a long-term source of groundwater contamination. In addition to the NAPL's solubility, DNAPL-water interfacial area is an important parameter that influences the rate of DNAPL dissolution in porous media. While many studies have focused on NAPL dissolution phenomena, there are few experimental studies on determining interfacial area in two-phase NAPL-water systems. In particular, the change of interfacial area as a consequence of continuous dissolution of immobile, entrapped NAPL blobs has yet to be investigated experimentally. The main objective of the proposed work is to experimentally investigate, in 30-cm-long columns, the effect of NAPL dissolution on specific entrapped NAPL-water interfacial area in well-characterized porous media. We want to generate a base line data set of specific interfacial area as a function of entrapped NAPL saturation during NAPL dissolution. This data can aid in the calibration and validation of existing and future models attempting to predict the efficacy of various aquifer remediation techniques. The EMSL Subsurface Flow and Transport Laboratory has the equipment (specialized columns, pumping systems, and a dual-energy gamma system for saturation measurements) and expertise to make these novel experiments feasible.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2007-06-25
End Date
2009-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Schroth, M.H., M. Oostrom, R. Dobson, and J. Zeyer. 2008. "Thermodynamic model for predicting fluid/fluid interfacial areas in porous media for arbitrary drainage/imbibition sequences." Vadose Zone Journal 7(3): 966-971.