I. Introduction – Scope of the review
The review will try to answer to two main goals: the product classification and the product removal in the nano-size range and specifically applied to wet suspensions. The product classification means the removal of the coarse fraction from a size distribution, targeting specific size regimes (e.g. those > 0.5 μm and those > 100nm). The product recovery is the removal of all particles from a suspension, down to several nanometers. In that case however, the separation may be done differently if the product of interest is the solid (the separation is focused on the recovery of particles in the nano-size range) or the liquid phase (the separation is focused on the liquid phase purification). Usually, one considers that nanoparticles are particles having their three dimensions lower than 100 nm. The size range covered by this review varies from a few nanometers to several microns or even more. One raison is that nanoseparation processes are often not specific technologies but current technologies that have been extended towards the submicronic range.