Reverse Osmosis (RO) is a membrane based and pressure driven technology applied to separate dissolved components (minerals, salts, organic molecules) from water. It splits a feed stream into a permeate with low and a concentrate with high dissolved matter concentration.

Membranes with different separation characteristics are available for the specific application (seawater, brackish water, nanofiltration…). The main membrane configuration is spiral wound flat sheets housed in pressure vessels. These modules are sensitive to fouling, i.e. the formation of unwanted layers which decrease the water flow through the membranes. Depending on the feed composition and the process design, feed pressures up to 150 bar can be required. The pressure of the concentrate can be recovered by Energy Recovery Devices (ERD) which leads to significant reduction of the overall energy consumption.