An Investigation of Residual Nonaqueous Phase Liquid Dissolution in Water Saturated Porous Media
Public Deposited- Last Modified
- February 27, 2019
- Creator
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Thyrum, Geoffrey Paul
- Affiliation: Gillings School of Global Public Health, Department of Environmental Sciences and Engineering
- Abstract
- Experiments were performed with a two-dimensional flowcell to analyze the size and shape distributions of nonaqueous phase liquid (NAPL) blobs in water saturated porous media. Photographs were taken of NAPL blobs allowing for the quantification of blob characteristics using image analysis methods. Results demonstrated that the blobs ranged in size and shape. Although the median blob size was relatively small, the fewer large blobs contribute to most of the NAPL residual. It was observed that the shape and number of blobs in a given region changed during the dissolution process. Blobs tended to become less complicated in shape during dissolution. Large irregularly shaped blobs of ten broke in to smaller blobs during the dissolution process. The longest lasting blobs originated from the breakup of initially large blobs. Experiments were performed with the two dimensional flowcell and a column apparatus to observe the shape and length of the dissolution front. The propagation of the dissolution front was recorded through sketches, photographs and with an x-ray attenuation apparatus. In many experiments, the dissolution front did not remain stable and dissolution fingers were observed. The fingering process was found to be a function of the initial length of residual, media packing, flowrate, and media size. Gravity did not seem to effect the development of dissolution fingers. Dissolution fingering was observed in an experiment containing a NAPL mixture. In general, finger lengths and widths increased during the dissolution process. A mathematical analysis demonstrated that maximum finger length theoretically increases with increasing flowrate and finger radius. Maximum finger length was shown to be inversely proportional to transverse dispersivity.
- Date of publication
- January 1994
- DOI
- Resource type
- Rights statement
- In Copyright
- Advisor
- Miller, Cass T.
- Turner, Alvis G.
- Imhoff, Paul T.
- Degree
- Master of Science in Environmental Engineering
- Academic concentration
- Water Resources Engineering
- Degree granting institution
- University of North Carolina at Chapel Hill
- Graduation year
- 1994
- Language
- Deposit record
- 043fb25a-cea5-4ac2-b0d3-5af4a220fe28
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