A reverse osmosis water plant is a facility that uses reverse osmosis technology to treat water. Its main goal is to remove dissolved salts, organic matter, microorganisms and other impurities in water through physical and chemical means to provide high-quality pure water.

Reverse osmosis (RO) is a common process for purifying or desalinating contaminated water by forcing it through a semipermeable membrane. This technology creates pure water by applying pressure to move water through a membrane, expelling impurities, salts, and other contaminants from the water. The pore size of the reverse osmosis membrane is extremely small, usually about 0.0001 micron, and can effectively filter out small impurities.