RESISTANCE ANALYSES FOR ULTRAFILTRATION IN TUBULAR MEMBRANE MODULE

The resistance analyses for ultrafiltration of macromolecular solution s by the resistances-in-series model and the modified gel-polarization model, respectively, have been extended to the turbulent ultrafiltrat ion system in this study. The experiments are carried out by ultrafilt rating dextran T500 solutions in a tubular membrane module with membra ne material of ZrO2-TiO2/carbon. It is found that the permeate fluxes are predicted very well by these models for both laminar and turbulent systems, and the resistance caused by the concentration polarization/ gel layer (R-p) can be reduced by increasing the crossflow velocity o n the membrane surface, Analysis by the resistances-in-series model sh owed that, R-p decreases with flow velocity with exponents of 0.49 and 0.99 for the laminar system and the turbulent system, respectively.