ANALYSIS OF SOLUTES REJECTION IN ULTRAFILTRATION

To establish an effective method of quantitative analysis in ultrafiltration, the rejection of six solutions of various molecular weights by cellulose acetate ultrafiltration membranes was studied. At first, the effects of concentration polarization were corrected. Mass transfer coefficients determined by the velocity variation method agreed very well with the Deissler correlation. Next, by using Spiegler and Kedem equations, transport of solute through ultrafiltration membrane was analyzed. A method of curve-fitting was found effective to determine two parameters, i.e. solute permeability P and reflection coefficient σ. Finally, these parameters obtained from experiments for various solutes were analyzed using the modified "pore theory", and were correlated with the ratio of the radius of solute and pore and with the effective pore length. Structure of the membrane was estimated from these results.