On the reversibility of membrane fouling by deposits produced during crossflow ultrafiltration of casein micelle suspensions

The formation of a deposit layer on membrane surfaces is an important problem, particularly in milk filtration. Properties the and efficiency removal can be studied using various indirect methods based mainly average resistance formation–deposit cycles, but their conclusions reversibility depend conditions surrounding analysis. Here we present method for direct characterization compression via analysis local solid concentration distribution during at constant pressure cross-flow velocity after relaxation. Two models are proposed characterization: model crossflow filtration with to characterize compressibility-permeability from data steady-state formation, evaluating swelling kinetics compressibility-permeability. was applied here formed surface polymeric ultrafiltration casein micelle suspensions 25°C. Local polarization probed situ small-angle X-ray scattering (SAXS). Experiments were performed special-purpose SAXS–filtration cell. It demonstrated that deposits obtained 1.1 bar transmembrane swell However, rate significantly lower than by modeling compressibility–permeability distribution. We thus find evidence produced undergo partially irreversible.