OPTIMIZING PROCESS TIME FOR ULTRAFILTRATION AND DIAFILTRATION

Models have been derived to predict process time and permeate volume for the purification of a macromolecule by ultrafiltration (in the concentration mode) or by continuous diafiltration. It requires only knowledge of the parameters of the film theory (gel-polarization) model for flux. Purification by discontinuous diafiltration usually results in less time and generates lower permeate volume than continuous diafiltration alone. The optimum appears to be a combined process where the feed is first pre-concentrated by ultrafiltration, followed by continuous diafiltration.