Effect of particle size and membrane pore size on crossflow microfiltration of micro-sized particle suspension using ceramic membranes

In order to obtain the selection method of membrane pore size and to understand fouling mechanism in suspension filtration, ceramic membranes of different properties were used to filter aqueous suspensions carrying fine particles of known size and chemical composition. By changing the membrane pore size, structure and particle size in a system and calculating the filtration resistances, the importance of the particle size/membrane pore size ratio to membrane flux was illustrated and fouling mechanism was understood. When d_p/d_m is less than 2.4, membrane fouling was produced by pore plugging and particle bridging; when d_p/d_m is larger than 2.4, the fouling was produced by cake layer deposited on membranes. A selection criteria of ceramic membrane pore size for fine particles microfiltration was also obtained. The membrane pore size should fall in the range of d_pd_m larger than 2.4 and less than 10 when filtering suspensions with fine particles of known size.