Reverse osmosis is a technology that uses a semi-permeable membrane to separate impurities in water. By applying high pressure, water molecules are forced to pass through a semi-permeable membrane that only allows water to pass from a high-concentration solution (such as salt water), intercepting pollutants such as dissolved salts, heavy metals, organic substances, and microorganisms, thus obtaining pure water. Its core lies in the selective permeation characteristics of the membrane. It is necessary to overcome the natural osmotic pressure to achieve separation against the concentration gradient. It is widely used in fields such as seawater desalination, industrial wastewater treatment, and drinking water purification.