Movement and Dissolution of a Viscous, Multicomponent Light Nonaqueous-Phase Liquid in a Fluctuating Water Table System
EMSL Project ID
5090
Abstract
Typical text book examples of Light Nonaqueous Phase Liquid (LNAPL) sources depict a continuous oil body, submersed in the capillary fringe. In case of past fluctuations of the groundwater table, the oil lens is assumed to overly a so-called smearing zone which is characterized by water-entrapped discontinuous lenses. This ideal behavior may be compromised when the LNAPL has a viscosity larger than water. In addition, most experiment studies on multi-fluid flow have been limited to single component LNAPLs. We propose a laboratory experiment, consisting of two separate parts, investigating both the behavior of a viscous, multi-component LNAPL in a fluctuating water table system and its subsequent dissolution.With respect to the movement of viscous LNAPL, our hypothesis, which will be tested in Part 1, is that the viscosity differences between the water and the LNAPL are likely to result in entrapment of continuous oil lenses beneath the groundwater table. During this first part of the experiment, a two-dimensional container with sands resembling those which occur in the underground at the Hanford site will be used. Initially, the groundwater will be maintained at such a level that the top part of the porous medium is partly saturated. Then a LNAPL consisting of components with a large solubility in solubility will be introduced and allowed to redistribute. After static equilibrium has been reached, quantitative measurements of NAPL saturations will be obtained using the newly constructed state-of-the-art dual-energy gamma radiation system, located in EMSL 1329. Subsequently, the groundwater table will be lowered in several steps, until a minimum level is reached, followed by gradual incremental increases of the water table. After the original water level has been reached, the LNAPL is allowed to come to static equilibrium. At that point in time, the container will be scanned again using the gamma system.
In the second part of the experiment we plan to investigate the mass transfer between the multi-component LNAPL source area and the ambient groundwater. This will be done by imposing a horizontal groundwater flow on the container. At regular intervals, groundwater samples will be extracted from sample ports in the flow cell and analyzed for dissolved organics. The resulting time series of aqueous phase concentrations will allow us to get insight in the emission of organic solutes from the source area, which is expected to consist of a combination of discontinuous LNAPL droplets and continuous oil lenses. Because a multi-component LNAPL will be used, we will be able to study preferential dissolution of the more water soluble component and the resulting weathering processes of both the oil lens and the discontinuous oil droplets.
Quantitative data obtained during both phases of this experiment will be used to validate two numerical codes: STOMP (Part 1) and Modelcode Olie (Part 2). It is anticipated that both parts of this experiment will result in separate papers in a peer-reviewed journal.
Project Details
Project type
Exploratory Research
Start Date
2003-11-11
End Date
2005-11-13
Status
Closed
Released Data Link
Team
Principal Investigator
Related Publications
Maki A, T Masiello, TA Blake, JW Nibler, and A Weber. 2009. "On the Determination of C0 (or A0), D0K, H0K, and Some Dark States for Symmetric-top Molecules from Infrared Spectra without the Need for Localized Perturbations." Journal of Molecular Spectroscopy 255(1):56-62.
Masiello T, A Maki, and TA Blake. 2009. "Analysis of the High-Resolution Infrared Spectrum of Cyclopropane." Journal of Molecular Spectroscopy 255(1):45-55.