FORMATION AND CHARACTERISTICS OF DYNAMIC MEMBRANE FOR ULTRAFILTRATION OF PROTEIN IN BINARY PROTEIN SYSTEM

A self-rejecting type dynamic membrane was formed by filtering a protein solution through a porous ceramic tube. In the dynamic membrane formed by a single protein (ovalbumin) solution, the effects of the linear velocity along the membrane, the bulk protein concentration, the pressure and pH in the feed solution on both membrane formation and ultrafiltration performance were studied in detail. The apparent protein rejection reached more than 0.8 in all cases. The volume fluxes at steady state increased with increasing linear velocity and with decreasing bulk concentration, but the pressure hardly influenced the flux. At the isoelectric pH. the flux in the early stages was the largest and that in the steady state of membrane formation was smallest. This behaviour is characteristic of a partially permeable dynamic membrane. The formation of a dynamic membrane was further attempted by using a binary mixture of proteins (ovalbumin and gamma-globulin) in solution. It is suggested that the formation of deposits occurred independently for the two proteins. The flux at steady state in the binary protein system agreed with the smaller flux in the corresponding single protein system.