Non-uniform Particle Size Explains Reduction in Filtration Rates with Transport Distance in Porous Media

Event Detail

Event type: Applied Mathematics and Computation Seminar
Date/Time: 11/06/2009-12:00   
Location: GLK 113
More info: http://www.math.oregonstate.edu/amc_seminar

Speaker info

Speaker: Son-Young Yi, University of Texas at El-Paso

Abstract:
Recent experimental studies of downward migration of polydisperse, micron-sized particles in porous media revealed that the classical colloid filtration theory fails to adequately predict irreversibly attached particle concentrations. This failure stems from an observed non-linear decrease in the irreversible particle attachment with transport distance. Here we present a theoretical analysis based on particle size distribution that captures the key features of these experimental results. We find that irreversible attachment rates are influenced by the surface area of particles rather than mass or volume, as expressed by a strong correlation between the irreversible attachment rate and the radius of the particles squared. Our analysis reveals that a small fraction (less than four percent) of the poly-disperse particle population is responsible for a decrease in the average irreversible attachment with transport distance. These particles have a larger average diameter than the rest of the population and, consequently, a higher than average irreversible attachment rate. Hence, the dependence of irreversible particle attachment on transport distance is a consequence of the non-uniformity of the particle sizes.