Model for colloidal fouling of membranes

Abstract

Abstract A proposed theoretical model describes colloids deposition on a membrane surface accounting for surface interactions. A mass‐transfer equation links the deposition rate to hydrodynamic conditions (permeation and tangential flow through a boundary layer thickness, δ) and to physicochemical properties of the suspension (diffusion, D, and potential barrier between particles, V B ). This equation predicts the existence of a critical flux, J crit , for ultrafiltration, reverse osmosis, or microfiltration of large‐size colloids as: Some of the trends observed when processing protein solutions are explained by this model. Previous experimental data for various colloids or our data with a clay suspension in the presence of electrolytes are also compared to predictions of our model. It explains the “flux anomaly” for particle sizes between 10 nm and 1 μm.