What is the difference between distilled water, deionized water, high purity water and ultrapure water?

2. Deionized water is the water passing through the cation exchange resin (usually a styrene-type strongly acidic cation exchange resin), then the cations in the water are absorbed by the resin, the cation H+ on the resin is displaced into the water, and the cation in the water Forming the corresponding inorganic acid; the water containing the inorganic acid is then replaced with water by anion exchange resin (usually a styrene-type strong basic anion) OH-, and combined with H+ in water to form water, which is deionized water. Deionized water has a very wide range of uses in modern industry. The use of deionized water is one of the important means to improve the quality of products in many industries in China and to catch up with the world's advanced level. Since the number of ions in deionized water can be artificially controlled, the physical, chemical, and pathological indexes such as resistivity, solubility, corrosivity, and viral bacteria are well controlled. In industrial production and laboratory experiments, if the process involving the use of water is used with deionized water, many parameters will be closer to the design or ideal data, and the quality of the product will become easier to control.

3. High-purity water refers to water with extremely high chemical purity. Its main application is in the fields of biology, chemical and chemical engineering, metallurgy, aerospace, electric power, etc., but its purity requirements for water quality are quite high, so the most common application is the electronics industry. For example, pure water used in power systems requires low levels of impurities to reach the "microgram / liter" level. In the production of pure water, the indicators specified in the water quality standards should be based on the production process of electronic (microelectronic) components (or materials) (such as the size of the particulate matter generally believed to cause damage to the circuit performance is its line width) 1/5-1/10), but due to the complexity of microelectronics technology and the factors affecting product quality, there is still no complete water quality standard for process production from a process test. However, in recent years, electronic water standards have been revised, and many breakthroughs and developments in the field of high-purity water analysis, the continuous application of new instruments and new analytical methods have created conditions for the development of water-making technology. The national standards for high-purity water are: GB1146.1-89 to GB1146.11-89 [168]. At present, the standard of high-purity water in China has five levels of electronic grade water: I, II, III, IV and V. This standard was developed with reference to the ASTM electronic grade standard.

4. Ultrapure water can be considered to be difficult to achieve in general processes. For example, if the resistivity of water is greater than 18MΩ*cm (without obvious boundaries), it is called ultrapure water. The key is to look at the purity of your water and various indicators such as conductivity or electrical resistivity, pH, sodium, heavy metals, silica, dissolved organic matter, microparticles, and microbiological indicators.