JEQ Grow Your Career With ASA
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     


Published online 17 July 2007
Published in J Environ Qual 36:1346-1356 (2007)
DOI: 10.2134/jeq2007.0004
© 2007 American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America
677 S. Segoe Rd., Madison, WI 53711 USA
This Article
Right arrow Figures Only
Right arrow Full Text Free
Right arrow Full Text (PDF) Free
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bradford, S. A.
Right arrow Articles by Toride, N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bradford, S. A.
Right arrow Articles by Toride, N.
Agricola
Right arrow Articles by Bradford, S. A.
Right arrow Articles by Toride, N.
Related Collections
Right arrow Colloids
Right arrow Microorganisms
Right arrow Microbial and Colloid Transport Models

TECHNICAL REPORTS

Vadose Zone Processes and Chemical Transport

A Stochastic Model for Colloid Transport and Deposition

S. A. Bradforda,* and N. Torideb

a USDA-ARS, United States Salinity Lab., 450 W. Big Springs Rd., Riverside, CA 92507-4617
b Faculty of Bioresources, Mie Univ., 1577 Kurimamachiya-cho Tsu, Japan, 514-8507

* Corresponding author (sbradford{at}ussl.ars.usda.gov).

Received for publication January 1, 2007. Profiles of retained colloids in porous media have frequently been observed to be hyper-exponential or non-monotonic with transport depth under unfavorable attachment conditions, whereas filtration theory predicts an exponential profile. In this work we present a stochastic model for colloid transport and deposition that allows various hypotheses for such deviations to be tested. The model is based on the conventional advective dispersion equation that accounts for first-order kinetic deposition and release of colloids. One or two stochastic parameters can be considered in this model, including the deposition coefficient, the release coefficient, and the average pore water velocity. In the case of one stochastic parameter, the probability density function (PDF) is characterized using log-normal, bimodal log-normal, or a simple two species/region formulation. When two stochastic parameters are considered, then a joint log-normal PDF is employed. Simulation results indicated that variations in the deposition coefficient and the average pore water velocity can both produce hyper-exponential deposition profiles. Bimodal formulations for the PDF were also able to produce hyper-exponential profiles, but with much lower variances in the deposition coefficient. The shape of the deposition profile was found to be very sensitive to the correlation of deposition and release coefficients, and to the correlation of pore water velocity and deposition coefficient. Application of the developed stochastic model to a particular set of colloid transport and deposition data indicated that chemical heterogeneity of the colloid population could not fully explain the observed behavior. Alternative interpretations were therefore proposed based on variability of the pore size and the water velocity distributions.




This article has been cited by other articles:


Home page
J. Environ. Qual.Home page
S. A. Bradford and E. Segal
Fate of Indicator Microorganisms Under Nutrient Management Plan Conditions
J. Environ. Qual., June 23, 2009; 38(4): 1728 - 1738.
[Abstract] [Full Text] [PDF]


Home page
J. Environ. Qual.Home page
G. Saini, C.H. Bolster, B.Z. Haznedaroglu, and S.L. Walker
Comments on "Diversity in Cell Properties and Transport Behavior among 12 Different Environmental Escherichia coli Isolates," by C.H. Bolster, B.Z. Hazendaroglu, and S.L. Walker in the Journal of Environmental Quality 2009 38:465-472
J. Environ. Qual., June 23, 2009; 38(4): 1775 - 1776.
[Full Text] [PDF]


Home page
Vadose Zone JHome page
S. A. Bradford and S. Torkzaban
Colloid Transport and Retention in Unsaturated Porous Media: A Review of Interface-, Collector-, and Pore-Scale Processes and Models
Vadose Zone J., May 27, 2008; 7(2): 667 - 681.
[Abstract] [Full Text] [PDF]


Home page
Vadose Zone JHome page
M. Flury and H. Qiu
Modeling Colloid-Facilitated Contaminant Transport in the Vadose Zone
Vadose Zone J., May 27, 2008; 7(2): 682 - 697.
[Abstract] [Full Text] [PDF]




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
The SCI Journals Agronomy Journal Crop Science
Journal of Natural Resources
and Life Sciences Education
Vadose Zone Journal
Soil Science Society of America Journal Journal of Plant Registrations The Plant Genome
Copyright © 2007 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.