alexa Coupled effect of extended DLVO and capillary interactions on the retention and transport of colloids through unsaturated porous media.
Environmental Sciences

Environmental Sciences

Journal of Bioremediation & Biodegradation

Author(s): Xu S, Qi J, Chen X, Lazouskaya V, Zhuang J,

Abstract Share this page

Abstract Colloids are potential vectors of contaminants in the subsurface environment. The knowledge of transport and retention behaviors of colloids is of primary importance for assessment and prediction of subsurface pollution risks. In this study, sand column experiments were conducted to investigate the coupled effects of various interfacial forces on the retention and transport of a hydrophilic silica colloid and a relatively hydrophobic latex colloid. Water column experiments were performed to observe the movement of colloids with air bubbles. Extended DLVO interaction energies and capillary potential energy were calculated to analyze colloid retention at air-water interface (AWI), solid-water interface (SWI), and air-water-solid interface (AWS). Results show that colloid retention decreases due to increase in electrostatic repulsion and Born repulsion as well as decrease in Lewis acid-base attraction and hydrophobic interactions. Water content effect and hydrophobic effect on colloid retention become more predominant in the solution of higher ionic strength. Colloid retention at AWI is minimal (i.e., due to nonexistence of primary and secondary minima) at the ionic strengths <75mM. Capillary potential energy (107-108 KBT) of colloids is 4-5 orders of magnitude greater than the extended DLVO interaction energy (~103 KBT), suggesting that capillary retention at AWS is the primary mechanism controlling colloid retention in unsaturated porous media. Results from this study show that immobile solid phase (e.g., soil) could be much more important than air phase in determining colloid retention in unsaturated porous media under unfavorable conditions, especially in the solutions of high ionic strengths. Copyright © 2016 Elsevier B.V. All rights reserved. This article was published in Sci Total Environ and referenced in Journal of Bioremediation & Biodegradation

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

  • 6th World Congress on Biofuels and Bioenergy
    Sep 5-6, 2017 London, UK
  • 6th World Congress on Biopolymers
    September 7-9, 2017 Paris, France
  • 7th International Conference and Exhibition on Biopolymers and Bioplastics
    October 19-21, 2017 San Francisco, USA

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version