Separative membranes technics

The membrane processes whose driving force is the pressure are physical separation processes.

A membrane is then defined as a thin material structure with holes called pores.

For a similar effect to that of a sieve, the particles or molecules are arrested if their sizes are greater than those of pores. If their sizes are smaller than those of the same pores the particles or molecules pass through the membrane.

This effect sieve separates particle species (mineral particles, microorganisms ...) the fluid from the suspension or separate / concentrate molecular species from their solvent.

There are four membrane processes : microfiltration, ultrafiltration, nanofiltration and reverse osmosis which are distinguished by the size of molecules / particles passing through the membrane.