As ultra-pure water is becoming more and more widely used, laboratory ultra-pure water machines are welcomed by more and more laboratories. Laboratory ultra-pure water equipment is convenient for water production, which can effectively improve work efficiency and can be greatly improved. Reduce water production costs and ensure water quality.
In addition, some high-end experiments such as animal and plant cell culture, effective liquid chromatography, mass spectrometry, plasma coupled spectroscopy, atomic fluorescence, gel analysis, cellular immunity, test tube baby, TOC analysis, PCR experiment, organic matter analysis, trace element detection, Two-dimensional electrophoresis, molecular biology experiments, genetics experiments, atomic absorption/emission spectroscopy, etc. These experiments have very strict requirements on the experimental water quality, not only the resistivity of the water quality, but also the organic matter, particulate matter, bacteria and pyrogens in the water quality, and the experimental pure water machine can meet these requirements.
The scope of application of laboratory ultrapure water machines involves hospitals, university scientific research, quality inspection units, chemical plants, pharmaceutical plants, water quality monitoring centers, animal husbandry, water plants, disease control centers, seed monitoring stations, battery factories, LCD screen factories, precision Circuit factory, dust-free product production, etc.
In the future, there will still be many experiments with high water quality requirements that require further development of ultrapure water. Not only the cost of water production must be reduced, but also the quality of produced water must be more stringent. Only continuous development can meet the ever-changing market requirements. The market share of experimental pure water machines will continue to increase in the future, but the requirements for product quality and after-sales service in the industry will be higher.
The laboratory ultrapure water equipment solves the complicated problem of laboratory ultrapure water production. It no longer needs to use large equipment to produce ultrapure water. The preparation of ultrapure water can be realized simply through small equipment, making the operation simpler and more convenient. .
The working principle of pure water machine and ultrapure water machine
Laboratory ultrapure water machines generally use professional reverse osmosis technology to produce pure water. The working principle of the pure water machine is to exert a certain pressure on the water, so that the water molecules and ionic mineral elements pass through the reverse osmosis membrane, and most of the inorganic salts (including heavy metals), organic matter, bacteria, viruses, etc. dissolved in the water It cannot pass through the reverse osmosis membrane, so that the permeated purified water and the impermeable concentrated water are strictly separated. The pore size of the reverse osmosis membrane is only 0.0001 micron, while the diameter of viruses is generally 0.02-0.4 micron, and the diameter of common bacteria is 0.4-1 micron. The water flowing out of the pure water machine meets the drinking water standard.
The ultrapure water machine is based on reverse osmosis technology, adding ion exchange and terminal treatment technology. Some have deep ion desalination, ultrafiltration and UV photooxidation equipment, and the water quality is better than the water quality requirements of the national standard GB/T6682-2008 laboratory water quality requirements.
Purification process of laboratory ultrapure water machine
Common impurities in natural water include soluble inorganic matter, organic matter, particulate matter, microorganisms, soluble gases, etc. The ultrapure water machine is to remove these impurities as effectively as possible. At present, the commonly used process methods for purifying water quality include distillation, reverse osmosis, ion exchange, filtration, adsorption, and ultraviolet oxidation. The ultrapure water machine can generally divide the water purification process into 4 major steps, pretreatment (primary purification), reverse osmosis (produce pure water), ion exchange (can produce 18.2MΩ.cm ultrapure water) and terminal Treatment (production of ultrapure water meeting special requirements).
1) Pretreatment Since the pretreated water will be further purified by reverse osmosis, it is necessary to remove impurities that affect the reverse osmosis membrane as much as possible; mainly including large particles, residual chlorine and calcium ions and magnesium ions. One point to be explained here is that different treatment units need to be equipped according to the difference of influent water quality. Most water purifier manufacturers cannot help customers solve this problem very well, which will lead to unsatisfactory results in subsequent purification and shorten the life of major components such as reverse osmosis membranes and ultra-purification columns. In order to solve this problem well, design precision filters, activated carbon adsorption filters and softening resins to remove large particles, residual chlorine and calcium ions and magnesium ions in the water to achieve a good pretreatment effect. The timely replacement of pretreatment consumables (the price is relatively low) is very important for the long-term stable operation of the ultrapure machine and the protection of core components.
2) Reverse osmosis Reverse osmosis uses a high-pressure pump to provide a high-concentration solution with a pressure greater than the osmotic pressure difference. Water molecules will be forced to pass through a semi-permeable membrane to the low-concentration side. Reverse osmosis can filter out 90%-99% of Most pollutants including inorganic ions, because of its superior purification efficiency, reverse osmosis is a very effective technology for water purification systems, because reverse osmosis can remove most of the pollutants, so it is often used as a front The treatment method can significantly prolong the service life of the deion exchange column. In view of the fact that reverse osmosis is very critical in the process of water purification and the replacement price of the reverse osmosis membrane is relatively high, we recommend that users must choose an ultrapure water machine with a protective function for the reverse osmosis membrane. In order to prolong the service life of the reverse osmosis membrane as much as possible and improve the filtration efficiency of the reverse osmosis membrane, a unique technology is adopted, combined with a professional reverse osmosis flow-limiting design, and a flow-limiting valve at the water outlet, so that the reverse osmosis membrane is always immersed in water without Lifespan is affected by drying out. Prolonging the life of the reverse osmosis membrane ensures the quality of the effluent water, and at the same time improves the cost performance of the ultrapure water system. The quality of the reverse osmosis membrane has a great influence on its life and the service life of the ultra-purification column, so we suggest that users must pay attention to the brands of reverse osmosis membranes, such as Dow and GE.
3) Ion exchange Ion exchange is the exchange of positive ions in water with H ions in ion exchange resin, and exchange of negative ions in water with OH- ions on ion exchange resin, so as to achieve the purpose of purifying water. Removing ions by ion exchange can theoretically remove almost all ionic substances. At 25°C, the resistivity of the effluent reaches 18.2MΩ. cm. The quality of the ion-exchanged water mainly depends on the quality of the ion-exchange resin and the exchange efficiency of water and resin in the exchange column. The quality of the ion exchange resin has a direct impact on the quality of the effluent water and the service life of the ultrapure water machine, so we suggest that users must pay attention to the brand of the resin, such as Dow and Rohm Ha. The service life is directly proportional to the relationship.
4) Terminal treatment mainly produces ultra-pure water of ultra-low organic type, sterile type, and non-pyrogenic type according to the special requirements of customers. There are a variety of treatment methods for different requirements, such as ultrafiltration for removing heat sources, dual-wavelength ultraviolet oxidation for reducing total organic carbon (TOC) in water, and microfiltration for removing bacteria. The ultrafiltration (UF) membrane is a molecular sieve, which is based on the size and allows the solution to pass through a very fine filter membrane to achieve the purpose of separating molecules of different sizes in the solution, and can reduce the heat source content in ultrapure water to 0.001EU /ml or less. The dual-wavelength UV oxidation method can use light to oxidize organic compounds to reduce the concentration of total organic carbon in ultrapure water to below 5ppb.
