In recent years, with the continuous increase in the country's investment in scientific research, higher requirements have been placed on experimental water, and the water quality standards for different industries also vary. Today, let's talk about what the water quality standards for laboratory ultrapure water machines are.
The laboratory ultrapure water machine uses a two-stage reverse osmosis water treatment process to produce ultrapure water. After a series of processing techniques, the water entering the ultrapure water machine becomes ultrapure water that meets the standards. However, the ultrapure water machine is based on reverse osmosis water treatment technology, combined with the application of ion exchange technology and terminal treatment technology. The water quality of the UOP laboratory ultrapure water machine meets the first-level water quality standards for laboratories in relevant parts of GB/T6682-2008.
Now let's first understand the purification steps of the laboratory ultrapure water machine, which mainly consist of the following four steps:
Firstly, there is the pretreatment unit of the ultrapure water machine, which conducts primary purification on the raw water.
After pretreatment, the feed water is processed through the reverse osmosis unit to produce pure water.
In the third step, after being treated with ion exchange resin, 18.2MΩ.cm ultrapure water can be prepared.
4. Terminal processing. That is, for those with strict requirements for experimental water, ultrapure water that meets special requirements can be produced by adding ultraviolet lamps, terminal microfilters, etc.
Generally, the water quality standards for laboratory ultrapure water machines mainly include:
Grade 1 water: It basically contains no dissolved or colloidal ionic impurities or organic matter. It can be produced by further treatment of secondary water. It is generally mainly used in analytical experiments with strict requirements, such as water for liquid chromatography analysis, etc.
Grade II water: It may contain trace amounts of inorganic, organic or colloidal impurities. It is used for inorganic trace analysis, such as water for atomic absorption spectrometry analysis, etc.
Grade 3 water: Suitable for general laboratory test water.
Water Quality Standard for Analytical Use in National Laboratories of China (GB/T6682-2008)
Note 1: As it is difficult to determine the true PH value of first-grade water and second-grade water under their purity, the PH value range of first-grade water and second-grade water is not specified.
Note 2: Due to the difficulty in determining oxidizable substances and evaporation residues at the purity of first-grade water, no limits are set for them. Other conditions and preparation methods can be used to ensure the quality of first-grade water.
The above is the water quality standard for laboratory ultrapure water machines. We hope it will be helpful to you when making a choice
