In reverse osmosis, what force is applied to purify water?
Seawater desalination and laboratory ultrapure water systems employ reverse osmosis relying on pressure-driven separation rather than chemical energy. Natural osmotic pressure of saline feed causes water to enter feed side diluting salts, governed by pi equals iCRT. For 35 grams per liter sodium chloride osmotic pressure about 27 bar. To obtain fresh water, feed compartment subjected to hydraulic pressure from high-pressure positive displacement pumps exceeding this value, commonly 50 to 70 bar for seawater, 15 to 25 bar for brackish. Thin-film composite polyamide membranes with charged surfac
Ref: Stryer et al., Biochemistry, Chapter: Reverse Osmosis and Hydrostatic Pressure Driven Purification.