ANALYSIS OF DEAD-END ULTRAFILTRATION BASED ON ULTRACENTRIFUGATION METHOD

In order to clarify the internal structures of the filter cake formed in protein ultrafiltration, ultracentrifugation experiments were condu cted. The local specific flow resistance at the various solution conce ntrations was determined by the sedimentation velocity technique. The porosity was related to the solute compressive pressure by the high-sp eed sedimentation equilibrium technique. A method has been developed f or evaluating the internal structures in the cake on the basis of a co mpressible cake resistance model using ultracentrifugation data. The d ecline in the filtration rate in dead-end ultrafiltration was accounte d for by considering the internal structures of the compressible cake. The properties of the cake were determined from ultrafiltration exper iments in which a filter was subjected to a sudden reduction in its fi ltration area. The results accorded well with the calculations. This s tudy revealed that the filtration behavior of ultrafiltration can be a ccurately described by a compressible cake resistance model.