Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 7-Day Trial for You or Your Team.

Learn More →

Pore‐scale mechanisms of colloid deposition and mobilization during steady and transient flow through unsaturated granular media

Pore‐scale mechanisms of colloid deposition and mobilization during steady and transient flow... The distribution of colloid‐associated contaminants and colloid‐sized microorganisms within the vadose zone is controlled, in part, by mobilization and retention processes. In this work, we present pore‐scale observations of colloid mobilization, transport, and retention within a transparent flow cell packed with partially saturated quartz sand. Our results show that colloid retention is dominated by adhesion to insular air bubbles at high moisture content and a combination of thin‐film straining and immobile water storage at low moisture content. Mobilization of retained colloids under steady flow is governed by slow exchange between zones of immobile and mobile water. During transient flow, characterized by increases in flow rate and moisture content, strained colloids are released from expanding thin films of water and from immobile water zones that reconnect with advecting pore water regions. On the basis of our observations we infer that colloid mobilization and retention within the vadose zone reflects contributions from multiple mechanisms that are sensitive to moisture content and flow regime. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Water Resources Research Wiley

Pore‐scale mechanisms of colloid deposition and mobilization during steady and transient flow through unsaturated granular media

Download PDF
9 pages

Loading next page...
 
/lp/wiley/pore-scale-mechanisms-of-colloid-deposition-and-mobilization-during-fNiS1Yw2ei

References (59)

Publisher
Wiley
Copyright
Copyright © 2006 by the American Geophysical Union.
ISSN
0043-1397
eISSN
1944-7973
DOI
10.1029/2005WR004233
Publisher site
See Article on Publisher Site

Abstract

The distribution of colloid‐associated contaminants and colloid‐sized microorganisms within the vadose zone is controlled, in part, by mobilization and retention processes. In this work, we present pore‐scale observations of colloid mobilization, transport, and retention within a transparent flow cell packed with partially saturated quartz sand. Our results show that colloid retention is dominated by adhesion to insular air bubbles at high moisture content and a combination of thin‐film straining and immobile water storage at low moisture content. Mobilization of retained colloids under steady flow is governed by slow exchange between zones of immobile and mobile water. During transient flow, characterized by increases in flow rate and moisture content, strained colloids are released from expanding thin films of water and from immobile water zones that reconnect with advecting pore water regions. On the basis of our observations we infer that colloid mobilization and retention within the vadose zone reflects contributions from multiple mechanisms that are sensitive to moisture content and flow regime.

Journal

Water Resources Research – Wiley

Published: Jan 1, 2006

There are no references for this article.