Particle capture in porous media when physico-chemical effects dominate

Abstract

The transport and capture of particles in porous media when the particles are submitted to hydrodynamics and physico-chemical effects were studied. Visualization experiments were performed using a porous media model consisting of a transparent, etched network of interconnected channels: particles were micrometric spheres of latex. Typically shaped particle deposits were observed in the pore space of the porous medium, preferentially close to the inlet. Their location depended on flow structure. Macroscopically, the kinetics of fouling were found to vary widely when the mean flow rate and ionic strength changed. The results have been intrepreted in terms of permeability and effluent concentration. In addition, a specific parameter, named apparent deposit area, was used to quantify and compare the whole images of particle deposition in the porous medium recorded during the experiments. Suprisingly, the apparent deposit area at the inlet correlates very well to the permeability.