Monte Carlo simulation of colloidal membrane filtration: Model development with application to characterization of colloid phase transition

Abstract

This study investigates phase transition from a fluid-like polarization layer to a solid cake layer of particle deposits during membrane filtration of interacting colloidal particles. A Monte Carlo simulation model of dead-end filtration is used under the influences of hydrodynamic bias from the permeation flux as well as inter-particle interactions. The model effectively demonstrates the roles of the hydrodynamic drag force and inter-particle potential in governing the volume fraction of the particle deposit. The cake layer volume fraction is shown to be sensitive to the combination of particle surface (zeta) potential, solution ionic strength, particle size, and applied transmembrane pressure. Further application of the model leads to a holistic characterization of the phase transition phenomenon. The onset of phase transition is characterized with flexibility and adaptability with concern for both physico-chemical standards, such as volume fraction and inter-particle separation distance, as well as pragmatic considerations, such as the desire to operate the system below the critical flux and avoidance of irreversible cake formation.