טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentKrasovitski Leonid
SubjectSurfactant Enhanced Aquifer Remediation
DepartmentDepartment of Civil and Environmental Engineering
Supervisors Professor Emeritus Jacob Bear
Professor Emeritus Abraham Marmur


Abstract

Surfactant Enhanced Aquifer Remediation (SEAR) is a promising soil cleaning technology. It has already been used for clean-up of aquifers contaminated by nonaqueous phase liquids (NAPL). The essence of the SEAR method is the application of a surfactant solution to a NAPL-contaminated soil in order to clean-up the entrapped blobs of the NAPL, which cannot be removed by using conventional remediation techniques. 

In this work, the main objective was to observe and study the pore-scale phenomena that occur in NAPL-contaminated porous medium models following the injection of a surfactant solution.  The emphasis was on studying the effects of different types of NAPL, washing agents, characterization of the NAPL patterns and different process scenarios on the cleaning efficiency and on the displacement mechanism. For each investigated case, the displacement process was recorded both at the REV-scale and at the pore-scale levels in order to provide a better understanding of the displacement mechanism. The use of image processing tools provided quantitative characterization of the NAPL displacement process at REV-scale and a comparison between the cleaning performance of the various systems. Mobilization mechanisms at pore level were revealed and classified.

Finally, a catalogue of observed pore-scale and REV-scale phenomena was prepared for the used types of cleaning agents and artificial porous media models. A new interpretation of the observed phenomena was proposed using model capillary systems and surfactant sorption schemes.