Application of a dynamic model for predicting flux decline in crossflow ultrafiltration

A semi-empirical crossflow ultrafiltration (UF) model that can predict permeate flux as a function of time for different operating conditions was considered. Model predictions were analysed and compared with the experimental results obtained in a crossflow UF plant under different operating conditions. The crossflow UF experiments were performed under different transmembrane pressures and crossflow velocities. Tubular ceramic membranes supplied by Orelis (France) were used. The molecular weight cut-off of the membranes was 15 kg/mol. They consisted of a TiO2–ZrO2 active layer on a carbon support. Polyethylene glycol with a 35,000 g/mol molecular weight was used as a standard macromolecule in the UF experiments to test the model. A solute concentration of 5 g/L was considered. Model predictions were better for low crossflow velocities.