KINETICS OF DEPOSITION OF COLLOIDAL PARTICLES IN POROUS-MEDIA

A theoretical framework for chemical-colloidal effects on the kinetics of deposition of Brownian particles in porous media has been presented. The theory was tested rigorously by conducting deposition experiments with model colloids and collectors under controlled chemical conditions in a well-defined experimental system. Experimental attachment (collision) efficiencies were calculated from measured particle deposition rates. The experimental results indicate that the attachment efficiencies are sensitive to the chemistry of the solution (electrolyte concentration and counterion type) but not to the large extent predicted by theory. A marked effect of particle size on attachment efficiencies is predicted by theory. Experimental attachment efficiencies, on the other hand, were virtually independent of particle size. DLVO theory is not successful in predicting the kinetics of deposition processes for Brownian particles flowing through porous media. Various explanations for the observed discrepancies are discussed. © 1990, American Chemical Society. All rights reserved.