Title Influence of cyclic freeze-thaw on the mobilization of LNAPL and soluble oil in a porous media
Author Iwakun, O.; Biggar, K.; Sego, D.
Author Affil Iwakun, O., University of Alberta, Department of Civil and Environmental Engineering, Edmonton, AB, Canada. Other: BGC Engineering, Canada
Source Cold Regions Science and Technology, 64(1), p.9-18, . Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0165- 232X
Publication Date Oct. 2010
Notes In English. Based on Publisher- supplied data GeoRef Acc. No: 309520
Index Terms cracks; freezing; freezing front; frozen ground; ground thawing; oil spills; permafrost; petroleum products; photography; pollution; porosity; porous materials; thawing; fissures; high-resolution methods; light nonaqueous phase liquids; movement; nonaqueous phase liquids; pollutants
Abstract Subsurface behavior of spilled fuel in freezing and frozen porous media including fractured bedrock is not well understood. To simulate a bedrock fracture, a freezing cell consisting of two parallel glass plates filled with glass beads was constructed to study the impact of cyclic freeze-thaw on LNAPL movement. The test procedure involved introduction of LNAPL atop the cell that contained water mixed with fluorescein dye. Freezing progressed from the top down, with observation and measurement of the LNAPL migration using a high-resolution digital camera and time-lapse photography. Both diesel and soluble oil were used for the experiments. Tests with soluble oil involved thorough mixing at 12.5% volume ratio with the fluorescein-water mixture in the freezing cell. The results showed upward mobility of the LNAPL under cyclic freezing and downward progressive expulsion of the soluble oil ahead of the advancing freezing front. The results corroborated literature findings on organic solute expulsion ahead of freezing front, and provided insight into the behavior of trapped LNAPL below the water table when subjected to freeze-thaw conditions. Additionally, micro fissures were observed in the formed ice inside the freezing cell under prolonged freezing. Such micro fissures may provide potential migration pathways for fresh spilled fuel in permafrost environments.
URL http://hdl.handle.net/10.1016/j.coldregions.2010.06.007
Publication Type journal article
Record ID 65006587