Various water quality standards in the water treatment industry

(1) soften water

Softening water refers to the water hardness (mainly refers to the water calcium, magnesium ions) remove or reduce a certain degree of water. During the softening process, only the hardness of water decreases, but the total salt content remains unchanged.

(2) desalinated water

Desalinated water is water in which salts (mainly strong electrolytes dissolved in water) are removed or reduced to a certain degree. Its conductivity is commonly 1.0 10.0 mu S/CM, resistivity (25 ℃) 0.1 1.0 M Ω CM, salt content of 1-5 mg/L.

(3) pure water

Pure water refers to water in which strong and weak electrolytes (such as SiO2, CO2, etc.) are removed or reduced to a certain degree. Its conductivity is commonly 10.0 0.1 mu S/CM, resistivity (25 ℃) > 0.1 10.0 M Ω · CM, salt < 1 mg/L.

(4) boiler water

Boiler water is to heat water at a certain temperature and pressure to produce steam, steam as a heat transfer and power medium. General industrial and mining enterprises often use low-pressure or medium-pressure boiler to generate steam as a source of heat or power, and this kind of boiler requires slightly less water quality. However, high pressure boilers are often used in power plants or thermal power stations to generate steam and drive steam turbines to generate electricity. In order to ensure that steam has no corrosion and scale deposition on steam turbines, such boilers have very high requirements on water quality. Therefore, the boiler water quality requirements according to the boiler pressure and temperature and different, no matter what kind of boiler water, it has a strict limit on the hardness of water. Other impurities such as dissolved oxygen, soluble silicon dioxide, iron and residual chlorine, which can lead to corrosion, scaling and soda-water cogeneration of boiler, water supply system and other thermal equipment, and which can cause ion exchange resin poisoning, should be mostly or completely removed.

(5) ultra-pure water

Ultrapure water refers to the water in which the conductive medium is almost completely removed, while non-dissociating gases, gels and organic substances (including bacteria, etc.) are also removed to a very low degree. Its conductivity is generally 0.1-0.055ms /CM, resistivity (25℃)> 10.0 megohm, salt content <0.1mg/L. Ideal pure water (in theory) conductivity is 0.055 mu S/CM, resistivity (25 ℃) of 18.0 M Ω · CM.