Program Three
Wednesday, May 21, 1997

Nonaqueous Phase Liquids Kansa C/D



C.A. Baldwin, Department of Chemical Engineering, Iowa State University, 1037 Sweeney Hall, Ames, IA 50011-2230 The contamination of ground water from Nonaqueous Phase Liquids (NAPLs) poses a serious threat to those who consume it. After a spill or leakage, NAPLs become trapped as small, discrete ganglia, which dissolve over time to contaminate water flowing through the region.

Remediation schemes based upon accelerated dissolution of the NAPL (such as pump and treat) are commonly used despite the fact that they may take many years to remove the contaminants due to the low aqueous solubility of many organic molecules.

Models of NAPL dissolution have failed to provide a predictive representation of real spills. One very common simplification made in most one-dimensional dissolution models is that ganglia are stationary throughout the dissolution process.

This assumption is typically justified by arguing that the pressure gradients across the length of any ganglion is not great enough for its displacement. A recent experiment using Magnetic Resonance Imaging (MRI) to image ganglion structure during a dissolution experiment show that substantial displacement occurs at pressures well below those normally thought to induce motion.

Typically, this displacement was seen early in the dissolution process, and it has been hypothesized that displacement can be attributed to mechanical instabilities which arise as a ganglion loses volume.

This work discusses the evidence for dissolution- induced displacement and its implications for modeling efforts. Furthermore, pore network models will be considered as a method of providing further information about these new results .

Key words: NAPL, ganglia, mobilization, modeling

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Tuesday, May 20, 1997

Metals Kansa A

Remediation of Munitions Compounds Kansa B

Analytical Methods Kansa C/D

General Topics Kansa B

Wednesday, May 21, 1997

Metals Kansa A

Zero-Valent Metals Kansa A

Remediation Kansa A

Vegetation-based Remediation Kansa B

Partnerships & Innovative Technologies Kansa C/D

Nonaqueous Phase Liquids Kansa C/D

Thursday, May 22, 1997

Biofilms & Barriers Kansa A

Bioremediation Kansa B

Partnerships & Technology Innovations Kansa C/D

Remediation Kansa C/D


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