The performance of the microfiltration process is controlled by the filter fouling due to the accumulation of solid matter forming a cake layer on the membrane surface. The objective of this work is to study the cake build up and growth at the particle level and to establish correlations with microfiltration performance measured at the process scale. A theoretical model coupling Navier-Stokes equation, convective/diffusion particle transport and deposit formation is developed to simulate a sequence of microfiltration in a confined geometry (Comsol Multyphysics). This model is used to make predictive simulations of cake growth during the filtration of diluted particles in the range of size of microorganism (5 μm). In the same time a specific filtration micro-system including an optical chamber and a microsieve (Aquamarijn) filtration membrane is designed in order to perform an experimental approach allowing in situ 3D-visualization of a deposit of model particles (polystyrene fluorescent microspheres) using Confocal laser scanning microscopy (CLSM). Based on image analysis, the cake building and properties (particle arrangement, thickness) are analyzed. These experimental data will be further used to improve the filtration model in order to obtain a predictive tool for process optimization.
Hassan, Ines Ben, Christine Lafforgue, Christophe Ellero, Abdelmoneim Ayadi, Philippe Schmitz