Date of Award
Master of Engineering Science
Civil and Environmental Engineering
DNAPLs in the subsurface may contain surface-active compounds that impact DNAPL migration and distribution. A number of studies to-date have focused on the role surface active compounds play in altering the wettability of quartz sands without examining the implications for other minerals commonly present in the subsurface. This study aims to extend the understanding of DNAPL/surfactant wettability to iron oxide surfaces. Specifically the objective was to compare the changes in the wettability of quartz and iron oxide sands in a tetrachloroethylene/water system containing a representative organic base. Wettability was assessed through: contact angles; Pc-S curves; and a two- dimensional flow cell experiment. It was discovered that quartz and iron oxide surfaces may exhibit different wetting characteristics under similar subsurface conditions. At neutral pH the quartz was strongly NAPL-wetting while the iron oxide remained hydrophilic. This study concludes that the isoelectric point, the pH at which there is a net zero surface charge, plays a major role in governing cationic surfactant sorption.
Molnar, Ian L., "THE WETTABILITY OF A DNAPL/SURFACTANT SOLUTION ON QUARTZ AND IRON OXIDE SURFACES" (2009). Digitized Theses. 3999.