A quantitative study of colloidal fouling in membrane processes

Abstract

Membrane fouling by colloids and/or nanoparticles is a severe problem plaguing membrane processes for water and wastewater as well as other industrial applications. The development and implementation of an effective fouling control strategy, hinges on the proper characterization and quantification of the feed water fouling strength. However, quantitative studies of colloidal fouling in membrane processes are limited and it is unknown to what extent the major mechanisms such as permeation drag and colloidal interaction forces influence it. In this thesis, a parameter termed the fouling potential is developed to determine the impact of feed water parameters on colloidal fouling. Through systematic experimental investigations, the influence of various physicochemical factors such as ionic strength, pH and driving pressure on the fouling potential were assessed. A numerical model to predict the fouling potential based on the classical theories of colloidal interaction and cake formation was subsequently developed and evaluated.