title: Porous media grain size distribution and hydrodynamic forces effects on transport and deposition of suspended particles.
abstract: The effects of porous media grain size distribution on the transport and deposition of polydisperse suspended particles under different flow velocities were investigated. Selected Kaolinite particles (2-30μm) and Fluorescein (dissolved tracer) were injected in the porous media by step input injection technique. Three sands filled columns were used: Fine sand, Coarse sand, and a third sand (Mixture) obtained by mixing the two last sands in equal weight proportion. The porous media performance on the particle removal was evaluated by analysing particles breakthrough curves, hydro-dispersive parameters determined using the analytical solution of convection-dispersion equation with a first order deposition kinetics, particles deposition profiles, and particle-size distribution of the recovered and the deposited particles. The deposition kinetics and the longitudinal hydrodynamic dispersion coefficients are controlled by the porous media grain size distribution. Mixture sand is more dispersive than Fine and Coarse sands. More the uniformity coefficient of the porous medium is large, higher is the filtration efficiency. At low velocities, porous media capture all sizes of suspended particles injected with larger ones mainly captured at the entrance. A high flow velocity carries the particles deeper into the porous media, producing more gradual changes in the deposition profile. The median diameter of the deposited particles at different depth increases with flow velocity. The large grain size distribution leads to build narrow pores enhancing the deposition of the particles by straining.
authors.affiliation: Normandie University, UNIHAVRE, UMR 6294 CNRS, LOMC, 76600 Le Havre, France. Electronic address: ahfirn@univ-lehavre.fr.
authors.forename: Nasre-Dine
authors.initials: ND
authors.lastname: Ahfir
authors.affiliation: Normandie University, UNIHAVRE, UMR 6294 CNRS, LOMC, 76600 Le Havre, France.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Hammadi
authors.affiliation: Normandie University, UNIHAVRE, UMR 6294 CNRS, LOMC, 76600 Le Havre, France.
authors.forename: Abdellah
authors.initials: A
authors.lastname: Alem
authors.affiliation: Normandie University, UNIHAVRE, UMR 6294 CNRS, LOMC, 76600 Le Havre, France.
authors.forename: HuaQing
authors.initials: H
authors.lastname: Wang
authors.affiliation: GeM, UMR 6183 CNRS, Université de Nantes, BP 420, 44606 Saint Nazaire Cedex, France.
authors.forename: Gilbert
authors.initials: G
authors.lastname: Le Bras
authors.affiliation: Normandie University, UNIHAVRE, UMR 6294 CNRS, LOMC, 76600 Le Havre, France.
authors.forename: Tariq
authors.initials: T
authors.lastname: Ouahbi
mesh_terms: D005374:Filtration / Q000379:methods*; D057446:Hydrodynamics; D007700:Kinetics; D055595:Mechanical Phenomena; D008956:Models, Chemical; D010316:Particle Size; D016062:Porosity; D012822:Silicon Dioxide
chemical_list: D012822:Silicon Dioxide
keywords: Grain size distribution; Particle size distribution; Porous media; Straining; Structured heterogeneity; Suspended particles