1. Notion of retention profile

Filtration of suspensions with a very low particle load (solid/liquid mass ratio of less than one thousandth), with particles smaller than the pore size of the filter medium, does not take place by cake formation on the porous medium, but by deposition in the filter mass. This is known as clarification. The concentration of the suspension (measured as the volume titer y ) decreases progressively from the filter inlet to the filter outlet (figure 1 ). The retained particles accumulate in the various layers of the filter, increasing the pressure drop and reducing the removal capacity of the porous bed. Developed by Herzig