(330a) Effect of Concentration Polarization on Flux Decline for Ultrafiltration in Tubular Membranes

The correlation equations for predicting local and average values of the permeate flux in tubular-membrane ultrafilters was derived from mass and momentum balances by the modified resistance-in-series model with the considerations of the increment of concentration polarization and the declines of transmembrane pressure and flow rate, along the membrane tube. Ultrafiltration of dextran T500 aqueous solution in a tubular microporous ceramic module has been carried out under various feed concentrations, transmembrane pressures and feed flow rates, and many experimental data of ten-point local permeate fluxes along the tube were obtained to confirm the correlation predictions. The increment of concentration polarization as well as the decline of permeate flux along the tube was also discussed.