Electro-microfiltration of Colloidal Suspensions

Crossflow microfiltration experiments using polymethyl methacrylate (PMMA) colloidal suspensions by a flat-channel electro-filter were performed to investigate the effects of electric field strength applied and the surface properties of particles, such as zeta potential and electric double-layer thickness, on the filtration rate, average specific cake filtration resistance, and cake porosity. Mathematical models for relating the quasi–steady state filtration rate and the separated distance between deposited particles on cake surface to the operating parameters were also presented. Both the experimental data and the theoretical model indicated that the filtration rate–electric field strength dependence was linear when the filter was operated in regions under the critical electric field strength. However, when the electric field was greater than the critical strength, the filtration rate was obtained by the addition of the electro-osmotic flux and the hydraulic permeate flux through the membrane. Due to the...