CROSS-FLOW FILTRATION OF POLYMER-SOLUTIONS BY CERAMIC MICROFILTRATION MEMBRANES

Cross-flow filtrations of ovalbumin and dextran solutions were carried out with four ceramic microfiltration membranes having respective pore diameters of 0.2, 0.8, 1.5 and 3.0μm. The effects of applied pressure. feed flow velocity, feed concentration and pore diameter on permeate flux and solute rejection were studied. Although the pore diameter was much larger than the diameter of an ovalbumin molecule, rejection was more than 90% in all experiments. The limiting fluxes were obtained, and lower feed velocity and higher feed concentration resulted in a lower limiting flux. The fluxes obtained in filtration of the ovalbumin solution were much lower than the pure water flux. Permeate resistance of the gel layer and that of plugging could well explain the cause of these low fluxes. Since the degree of plugging depended on membrane pore diameter, an optimum pore diameter for obtaining high flux existed. Dextrane was hardly rejected with the ceramic membranes used. The flux gradually decreased with time because of plugging of the pores. © by THE SOCIETY OF CHEMICAL ENGINEERS, JAPAN.