Cross-flow and dead-end microfiltration of oily-water emulsion. Part I: Experimental study and analysis of flux decline

Abstract

Microfiltration for the separation of oil-in-water emulsions has been investigated and a method of identifying fouling mechanisms applicable to microfiltration in general has been developed. For a variety of membranes, simultaneous experiments in both dead-end and cross-flow modes have been performed at various pressures, and in the latter case at different cross-flow velocities. The oil phase comprised dodecane at 1000 ppm. Initial fouling rates were very significant with the two polymeric membranes used but distinctly less severe with the Ceramesh membrane, possibly due to its tight pore size distribution. Good performance was achieved with this membrane under turbulent flow conditions. Flux decline and rates of permeate flow resistance change have been analysed using a new formulation of the equations illustrating a method of resistance mechanism recognition.