Colloidal interaction and membrane fouling

Abstract

Membrane fouling refers to the deposition of foulants on a membrane surface or inside the membrane pores, which leads to increased hydraulic resistance of the membrane. Among the various types of membrane fouling, colloidal fouling plays an important role. Excessive deposition of colloids can cause severe loss of membrane permeability and solute rejection. Membrane colloidal fouling is largely governed by the interplay of hydrodynamic forces and colloidal interaction. This presentation will systematically discuss the role of membrane permeate flux, colloidal interaction, and water chemistry on the fouling of reverse osmosis, nanafiltration, and ultrafiltration membranes. A simple theoretical framework is established to understand the seemingly contradictory experimental results, and its implications for optimal membrane operation will be discussed. The effect of inter-species interaction between different foulant species on membrane flux behaviour will also be discussed for feed waters containing mixtures of foulants.