Chemicals are used to wash the membranes (coiled spiral, tubular, hollow fiber, ceramic) to remove the fouling of different organic / inorganic / biological nature which, depositing on the membranes themselves, can gradually reduce their permeability.

The process accelerates its course progressively due to the increase in surface roughness and therefore an increase in the possibility of adhesion. It is therefore necessary to plan carefully the frequency of washing, as well as the type of the same (depending on the soiling agent) using specific detergents.