Fagerlund, Fritjof; Yang, Zhenjing; Illangasekare, T H; Niemi, A; Phenrat, T; Lowry, G V (2012): Dissolution of a spatially variable DNAPL (dense non aqueous phase liquid) source [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.778621, Supplement to: Fagerlund, F et al. (submitted): Dissolution of a spatially variable non-aqueous phase liquid source: generation of an experimental dataset and comparison of models. Computers & Geosciences
Always quote citation above when using data! You can download the citation in several formats below.
Published: 2012-04-01 • DOI registered: 2012-05-20
Abstract:
Dissolution of non-aqueous phase liquids (NAPLs) or gases into groundwater is a key process, both for contamination problems originating from organic liquid sources, and for dissolution trapping in geological storage of CO2. Dissolution in natural systems typically will involve both high and low NAPL saturations and a wide range of pore water flow velocities within the same source zone for dissolution to groundwater. To correctly predict dissolution in such complex systems and as the NAPL saturations change over time, models must be capable of predicting dissolution under a range of saturations and flow conditions.
To provide data to test and validate such models, an experiment was conducted in a two-dimensional sand tank, where the dissolution of a spatially variable, 5x5 cm**2 DNAPL tetrachloroethene source was carefully measured using x-ray attenuation techniques at a resolution of 0.2x0.2 cm**2. By continuously measuring the NAPL saturations, the temporal evolution of DNAPL mass loss by dissolution to groundwater could be measured at each pixel. Next, a general dissolution and solute transport code was written and several published rate-limited (RL) dissolution models and a local equilibrium (LE) approach were tested against the experimental data. It was found that none of the models could adequately predict the observed dissolution pattern, particularly in the zones of higher NAPL saturation. Combining these models with a model for NAPL pool dissolution produced qualitatively better agreement with experimental data, but the total matching error was not significantly improved. A sensitivity study of commonly used fitting parameters further showed that several combinations of these parameters could produce equally good fits to the experimental observations. The results indicate that common empirical model formulations for RL dissolution may be inadequate in complex, variable saturation NAPL source zones, and that further model developments and testing is desirable.
Comment:
Data in each text file are given in three columns:
1) horizontal coordinate x [cm],
2) vertical coordinate y [cm],
3) NAPL (non aqueous phase liquid) saturation [unitless].
The origin for the spatial coordinates is the lower left corner of the fine, white Unimin # 50 sand as shown in Figure 1 of the paper. The file named "NAPLsat_1day" is the initial condition and considered time=0, consequently, NAPLsat_2days refers to measured NAPL saturations after 1 day of dissolution since time zero and so on. The files having an extension "_3x3filer" contain data that have been filtered using a 3 by 3 median filter. The data are given at 2 mm x 2 mm scale. The user can chose to aggregate to a larger scale if desired.
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | File name | File name | Fagerlund, Fritjof | |||
| 2 | Uniform resource locator/link to file | URL file | Fagerlund, Fritjof | File format: ascii/text, size 65 kb |
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
34 data points