An Experimental Investigation on DNAPL Migration in Saturated Porous Medium Models

Resistance on DNAPL droplets settling in a saturated porous medium and DNAPL migration behavior through a saturated pore is experimentally investigated. Motion of a settling droplet is descnbed by an equation, which is similar to that for a rigid solid sphere settling in an infrnite liquid medium. A correlation between droplet Reynolds number (Re) and comprehensive resistance coefficient (CR) is established for each droplet size. The results indicate that a settling droplet wobbles throughout its motion in a porous medium. Equivalent DNAPL thickness (h) in a saturated pore just before and after snap-off is correlated to pore neck area in rectangular and triangular pores. It is found that the power and linear relation hold well in the fonner and latter cases respectively within the data range ofthis study. Three different stages in DNAPL migration through a saturated pore are observed. The results indicate that the migration behavior depend on both geometry and DNAPL physical properties