Reverse osmosis is a treatment process that reduces the salinity of water. The principle is based on the use of a semi-permeable membrane that retains the salts contained in the water and produces partially demineralised water.

Depending on the chemical nature of the raw water, and in order to increase operating efficiency, an antiscalant is injected into the make-up water to prevent the precipitation of mineral salts such as calcium carbonate, calcium sulphate, silica...

Membranes may also be cleaned at regular intervals or as part of a remedial operation following an operating incident.