An experimental study of the transport and capture of colloids in a porous medium subjected to step increases in concentration

Abstract

This paper presents an experimental study of the passage and retention of colloids in a porous medium. The experiments are peformed using standard liquid chromatography equipment and involve detecting step injections of latex particles passing through the bed packed with glass beads. The results are presented in terms of the fraction of latex passing through the column as a function of the number of pore volumes of effluent. We have pointed out the predominant role of the ionic strength, which is in qualitative agreement with DLVO theory and of the intensity of hydrodynamic forces such as the drag force. The combined effects of these parameters give rise to zones where latex particles deposit preferentially. We have attempted to visualize these immobilization zones using a scanning electron microscope.