Reverse osmosis is a technology developed in the 1960s, in which saline or impure water is forced through a semipermeable membrane that retains dissolved salts and impurities, resulting in purified water.

The membrane separation process removes more than 99% of total dissolved solids, organic matter, bacteria, and other particulates.

The permeate flow rate is adjusted based on operational parameters such as temperature, osmotic pressure, conductivity, and recovery.

Changes in operational parameters, such as a decrease in permeate flow, an increase in osmotic pressure, or a rise in conductivity, indicate variations in operating conditions and may be caused by fouling, scaling, or microbiological growth.

The feed water of a reverse osmosis system must be dechlorinated to prevent membrane oxidation. The rate of chlorine attack depends on the characteristics of the feed water. In an alkaline pH, membrane oxidation due to chlorine exposure occurs faster than in a neutral or acidic pH. Chlorine damage also accelerates with higher temperatures and increased concentrations of heavy metals, such as iron.