  A filtration procedure was developed to measure the reversibility of fouling
during cross-flow filtration based on the square wave of applied pressure. The
principle of this method, the apparatus required, and the associated
mathematical relationships are detailed. This method allows for differentiating
the reversible accumulation of matter on, and the irreversible fouling of, a
membrane surface. Distinguishing these two forms of attachment to a membrane
surface provides a means by which the critical flux may be determined. To
validate this method, experiments were performed with a latex suspension at
different degrees of destabilization (obtained by the addition of salt to the
suspension) and at different cross-flow velocities. The dependence of the
critical flux on these conditions is discussed and analysed through the osmotic
pressure of the colloidal dispersion.

Soft Condensed Matter