The working principle of reverse osmosis membrane

The working principle of reverse osmosis membrane

           The working principle of reverse osmosis membrane: The membrane that is selective to the permeable material is called semi-permeable membrane. Generally, the membrane that can only pass through the solvent but not the solute is called the ideal semi-permeable membrane. When the same volume of dilute solution (such as fresh water) and concentrated solution (such as salt water) are placed on both sides of the semi-permeable membrane, the solvent in the dilute solution will naturally pass through the semi-permeable membrane and flow spontaneously to the side of the concentrated solution. This phenomenon is called penetration. When the osmosis reaches equilibrium, the liquid level on the side of the concentrated solution will be higher than the liquid level of the dilute solution by a certain height, that is, a pressure difference is formed, and this pressure difference is the osmotic pressure. Reverse osmosis is a reverse migration movement of osmosis. It is a separation method that separates the solute in the solvent from the solvent by the selective retention of a semipermeable membrane under pressure. It has been widely used in the purification of various solutions And concentration, the most common application example is in the water treatment process, the use of reverse osmosis technology to remove impurities such as inorganic ions, bacteria, viruses, organic matter and colloids in the raw water to obtain high-quality pure water.