A partly permeable membrane is used in the reverse osmosis (RO) method of water purification to extract bigger particles, undesirable compounds, and ions from drinking water. In reverse osmosis, osmotic pressure, a cooperative property caused by potential chemical differences of the solvent, a thermodynamic characteristic, is overpowered by an applied force. Reverse osmosis is utilized in industrial operations and the creation of drinkable water because it can remove many biological species (primarily bacteria) and dissolved and suspended chemical species from water. Consequently, the pure solvent crosses the membrane’s other side while the solute is on the pressured side.

In contrast to filtering, reverse osmosis uses an osmosis process to move fluid over a membrane. The method may attain complete efficiency independent of variables like the solution’s pressure and concentration since the primary removal mechanism in membrane filtration is straining, or size exclusion, when the pores are 0.01 micrometers or more significant. Instead, reverse osmosis employs solvent diffusion over a nonporous membrane or nanofiltration with pores as small as 0.001 micrometers. Differences in solubility or diffusivity are the primary removal method, and the process depends on pressure, solute concentration, and other factors.

Reverse osmosis is most famously used to purify saltwater into drinkable water by eliminating the salt and other waste products from the water molecules.

Reverse osmosis systems are often used in domestic drinking water filtration systems across the globe to improve water quality for drinking and cooking.

Such systems generally consist of the following steps:

• A sediment filter with smaller holes captures particles such as rust and calcium carbonate if desired.
• A thin-film composite membrane may need an activated carbon filter to stop organic compounds and chlorine from attacking and degrading it.
• A second carbon filter to catch chemicals that the reverse osmosis membrane did not remove, a thin-film composite membrane reverse osmosis filter, an ultraviolet lamp to sterilize any microbes that might avoid the reverse osmosis membrane’s filtering, and optionally, a second carbon filter to capture those chemicals.

In some setups, a cellulose triacetate membrane is employed instead of the carbon prefilter. A membrane created from a by-product of paper called CTA (cellulose triacetate) is attached to a synthetic layer and designed to interact with water’s chlorine. To stop bacteria from growing on them, the water supply has to have a small quantity of chlorine. CTA membrane rejection rates typically range from 85 to 95 percent. The thin-film composite membrane is susceptible to degrading when exposed to chlorine, but the cellulose triacetate membrane is prone to rotting unless protected by chlorinated water. Chlorine must be removed from the water before reaching a synthetic material’s thin-film composite (TFC) membrane. All household reverse osmosis systems require carbon filters as a pre-treatment to prevent chlorine damage to the TFC membrane components. Compared to CTA membranes, TFC membranes have a higher rejection rate of 95–98% and a longer lifespan.

Water may be readily purified with the technology included in Propello reverse osmosis filters. Additionally, they ensure that the essential minerals in the water are preserved so that you may benefit from them in terms of your health. These filters may be used to clean water, which can then be used to create calm, refreshing beverages for your visitors. You may consume water in your home with the help of these reliable appliances without a care in the world.