DYNAMICS OF COLLOID DEPOSITION IN POROUS-MEDIA - MODELING THE ROLE OFRETAINED PARTICLES

A model for the dynamics of colloid deposition in porous media is deve loped by combining macroscopic and microscopic theories of particle de position. The model considers the non-uniform coverage of collector su rfaces by retained particles during the deposition process. A flux-cor recting function is introduced that enables the determination of the o verall colloid deposition rate as a function of surface coverage. A no n-linear dependence of particle deposition rate on surface coverage is obtained, in agreement with experimental data of particle deposition. It is shown that the model is successful in describing the blocking ( excluded-area) effect in particle deposition dynamics.