Comparing Favorable and Unfavorable Attachment of Colloids in a Discrete Sandstone Fracture
Year: 2017
Type: dissertation
Abstract: This study compares the results of cationic amine-modified latex (favorable attachment) and anionic carboxylate modified latex (unfavorable attachment) microsphere transport through a discrete sandstone fracture. Two microsphere sizes (200 nm and 1000 nm), two ionic strengths (5 mM and 10 mM), and two specific discharges (0.35 mm.s-1 and 0.70 mm.s-1) were tested to observe the impact on transport under both attachment conditions. The effect of ionic strength was significant for unfavorable attachment due to the presence of a secondary minimum, but not significant for favorable attachment conditions. The recovery of anionic microspheres resembled favorable attachment when cationic microspheres attached to the sandstone surface and created surface charge heterogeneities. For all conditions tested there was less separation between favorable and unfavorable attachment than would be expected in a comparable porous media study, which was attributed to less contact between the colloid and collector and higher specific discharge in fractured media.
Source: TSpace (University of Toronto)
Author: Sean Patrick Spanik
Language: English
Subfield: Environmental Engineering
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2776489253