Simultaneous prediction of flux and retention for osmotic pressure controlled turbulent cross flow ultrafiltration

A mathematical model is developed for quantification of concentration polar ization phenomena during osmotic pressure controlled ultrafiltration under turbulent flow conditions. An integral method is used for the solution of t he concentration profile in the developing mass transfer boundary layer in a rectangular channel. The model is used to predict the permeate flux and o bserved retention simultaneously during cross flow ultrafiltration. The res ults from the numerical solution of the model equations are compared with t he existing data from the literature for dextran (T-70) over a range of ope rating conditions. The predictions are found to be in excellent agreement w ith the experimental results. Furthermore, a detailed parametric study has been undertaken to investigate the effects of system parameters (e.g. press ure difference, cross flow velocity, bulk concentration, real retention, et c.) on the system performance (permeate flux and observed retention). (C) 2 000 Elsevier Science B.V. All rights reserved.