Reverse osmosis drinking water system is a water treatment unit. It uses water pressure to reverse a natural physical process called osmosis. Water, under pressure, is forced through a semi-permeable membrane to filter out minerals and impurities. Treated drinking water goes to the faucet. Minerals and impurities are sent to the drain with RO wastewater. The system includes replaceable filters and membrane elements. The prefilter reduces sand, silt, dirt, rust particles, other sediments, and chlorine from the water supply before they enter the RO membrane elements. The post filter reduces any tastes and/or odors that may remain in the water after passing through the RO membrane elements

The function of the reverse osmosis membranes in water desalination is essentially the same as the function of reverse osmosis in the treatment of wastewater, rejection of electrolyte and permeating the water. In the following decades, there have been significant advances in reverse osmosis membranes, and this has included the development of different membrane materials.

Reverse osmosis seawater desalination systems are applied for the purification of groundwater, which are polluted by salt and heavy metals. It provides fresh water to hotels, resorts, villages, offshore installations and onboard ships. High-pressure pumps are used in reverse osmosis seawater desalination systems. It is used for co- generation plants for additional production of drinking water using off-peak electrical energy.

Reverse osmosis systems use RO membrane technology, where the water is forced against a semi-permeable membrane, which is able to separate the water from contaminants dissolved in the water. RO systems for home use are designed for undersink installation. These typically include an RO membrane cartridge; a sediment prefilter that protects the RO membrane; a carbon postfilter that removes any remaining chemicals and gives the water a good taste; a storage tank for treated water; and a faucet to be installed on the countertop. Some systems come with an extra carbon prefilter for additional protection of the RO membrane.

Salt recovery systems are used for the recovery of commercial salts from brines. It is an evaporation/crystallization system for the production of sodium chloride. This recovery system includes a rotary drum filter, rotating cylinder dryer, and screens.

Saltwater chlorination is a process of sanitizing water, using chlorine that is produced in the pool water from ordinary salt. A low concentration of salt is added to the water. As water passes over the chlorinator's specially coated plates, an electric current breaks down the salt and water into their basic elements to form hypochlorous acid. It is the active sanitizer in all forms of chlorine. The chlorine kills algae and bacteria in the water and oxidizes the waste. The chlorine regenerates itself back to salt and begins the process over again in a virtually unending cycle. An occasional addition of salt is needed only to replace what is lost due to splash out, pump out, draining or backwashing.

A screen filter is a single, thin layer of a material that has a symmetrical arrangement of openings or passages called pores. These pores trap all particles larger than the pore size on the surface of the filter. This process is called sieving, or size exclusion, and is the classic filtration method. It utilizes a rigid or flexible screen to separate sand and other fine particles out of water for irrigation or other applications. Typical screen materials include stainless steel (mesh), polypropylene, and nylon.

Sediment filters are used to reduce solid particulate transported by a fluid. It acts as a sieve to remove these particles. The function of this filter is to remove particles from water are rated by a micron number. This refers to the particle size that will be trapped by the filter. A fifty micron filter traps particles of 50 microns or larger, while a 2 micron cartridge traps particles of two microns or larger. Sediment filters can be made of a variety of materials. Wound string or cord, polypropylene, polyester, cellulose, ceramic, glass fiber, and cotton are among the most common.

Service Deionization is a convenient, safe and economical way to produce high-purity deionized water. It uses individual cartridges or tanks for the anion, cation, and mixed beds. When the individual cartridges are exhausted, the supplier replaces them with recharged units on site and the exhausted cartridges are removed to be regenerated at the supplier's premises. This arrangement eliminates the need to store chemicals. In addition, it saves water that does not have to be used for backwash.