Why is ultrapure water called "hungry water"? 【Basic Knowledge】

Water that is further refined than pure water? The surprising properties and capabilities of ultrapure water!

■What is the difference between pure water and ultra-pure water in terms of purification methods? Pure water refers to water that has undergone treatment to remove impurities from tap water, while ultra-pure water is further purified using a combination of reverse osmosis membranes, ion exchange resins, activated carbon, ultraviolet light, and ultrafiltration membranes, enhancing its specific resistivity to 18 MΩ·cm or higher. ■Why is 18 MΩ·cm the standard for ultra-pure water? Water ionizes very slightly on its own, so even if impurity ions are reduced to nearly zero, the effects of this ionization remain. Therefore, the theoretical upper limit for specific resistivity is considered to be around 18.2 MΩ·cm, which serves as the standard for ultra-pure water. ■Why is ultra-pure water referred to as "hungry water"? Ultra-pure water contains almost no impurities, making it more likely to absorb surrounding substances, which is why it is sometimes called that. This property is utilized in cleaning processes, allowing for the maximum removal of invisible ions and organic materials, and it is also used in the cleaning processes of precision equipment such as semiconductors.

Pure water production equipmentUltrapure water production equipmentPure water production equipment