Pure water, also known as deionized water, refers to water that meets the hygienic standards for domestic drinking water as the raw water, through the electrodialyzer method, ion exchanger method, reverse osmosis, distillation and other appropriate processing methods, made sealed in containers, and does not contain any additives, colorless and transparent, directly drinkable water, which can also be called pure (in chemistry), used more in the test, but also due to be made by Distillation and other methods of production, it is also known as distilled water. Space water sold on the market, distilled water are pure water; but pure water or drink less for the better, because it does not have too many minerals that the human body needs. Pure water is not easy to conduct electricity, is an insulator. Lead-acid battery replenishment to use pure water.
Water refers to the impurity-free H2O. from an academic point of view, pure water, also known as high-purity water, refers to the chemical purity of the water is very high, and its main applications in the biological, chemical chemical industry, metallurgy, aerospace, power and other fields, but its water purity requirements are quite high, so the general application of the most common or the electronics industry. For example, the pure water used in the electric power system, the requirements of the impurity content of low to "micrograms / liter" level. In the production of pure water, water quality standards for the indicators should be based on electronic (microelectronics) components (or materials) of the production process (such as the general view that the size of the particulate matter caused by the destruction of the circuit performance of the line width of 1/5-1/10), but due to the complexity of microelectronics technology and product quality of the factors affecting the product quality, so far there is no one by the process of experimentation applicable to a certain circuit Production of a complete water quality standards. With the continuous revision of electronic grade water standards, but also many breakthroughs and developments in the field of high-purity water analysis, new instruments and new analytical methods are constantly applied to create the conditions for the development of pure water process.
Pollution factors
1 Pure water contaminated by microorganisms Pure water contaminated by microorganisms is a variety of factors, but there are three main factors.
1.1 Enterprises do not pay attention to food hygiene, despite the development of relevant operating procedures and systems, but the supervision is not strong enough, in the production process, the procedures and systems have not been implemented and enforced, we found that some factories in the survey has a modern plant, advanced foreign production machinery and perfect air purification and disinfection equipment, but the production of purified water is sometimes the result of the test colonies The total number of bacteria per milliliter is zero, sometimes detected a few or even dozens, through in-depth investigation found that the batch number of bacteria detected is two days after the suspension of production and then start production is not in accordance with the provisions of the strict disinfection caused by. The existence of such a phenomenon often results in unstable product quality. Li Hong et al [1] reported that water treatment terminal filters and filling workers' hands are the key microbial contamination links in the production process of bottled mineral water. In the process of pure water production, each link may be contaminated with microorganisms, the key depends on the production staff's sense of hygiene and the degree of strict implementation of various operating procedures.
1.2 The production process is unreasonable, imperfect facilities, is also one of the main factors causing microbial overload. Using different water sources, the production of different types of pure water process is different, the general principle is to achieve the premise of purification, the simpler the better, the shorter the process is easier to control the quality of product health. At present, the process of pure water is basically a water source → filtration → purification → ozone mixing disinfection → filling → inspection → storage. The advantage of this process is that the filling of pure water is still left in the ozone, if the air from the bottle or cap and filling room with a small number of microorganisms can also achieve the purpose of killing to keep the product sterile. We have learned that some manufacturers of imperfect equipment or in the pure water after ozone mixing and disinfection is not directly filled, but through the storage tank to stay for a certain period of time before filling, the results of the test found that the presence of bacteria. Xu Rongnian et al [2] reported that the water filling into the bottle before staying 0.5 ~ 2 h, ozone about 2 ~ 8 decay period, the ozone concentration in the water is greatly reduced, even if the processed water itself is sterile, but in the filling into the bottle can not be killed because of the packaging or filling the air between the reintroduction of residual bacteria. From the above theory that this process, bottles and caps and filling room must ensure sterility, otherwise the product must have microbial presence, but in practice it is difficult to do.
1.3 Low level of technology, the performance of a variety of equipment seem to understand, is also another factor leading to microbial contamination. We found in the field survey, certain manufacturers of technical personnel to effectively kill microorganisms ozone generator and control microbial facilities to understand very superficial, despite the installation of pure water disinfection is currently considered the best ozone generator and air purification equipment, but can not be applied to its effective performance or in the production of its most effective role in the production of micro-organisms are often detected in the product. Currently using ozone to treat pure water is the basic principle of ozone and water mixing, and make its final concentration in the water to reach 0.5 mg / L to meet the sterilization requirements, according to this parameter, the enterprise should be based on the production of the actual dosage to estimate the amount of ozone that should be produced by the ozone generator. In addition, must also consider the actual production of the actual operable yield of the equipment, such as a long time after the use of equipment performance decline, should be adjusted appropriately, and through the effective measurement; ozone and water mixing is complete, and ultimately whether to achieve the sterilization requirements of the dose as well as the time that can be maintained, etc., is the ability to achieve the killing intensity of the most basic factors. Air purification equipment is the same, some manufacturers can not properly use and maintenance to ensure the normal operation of the purification equipment and the best purification effect. Always think that the installation of air purification equipment, purified air is sterile, the product will certainly be qualified, but also did not regularly test the degree of air purification, the above phenomenon reflects the technical level of technicians directly affect the quality of product health.
2 measures to control microbial contamination Pure water is a special product, once a few microbial contamination, it may exceed the standard, and even flocculent precipitation and other consequences. Therefore, the control of microbial contamination is a very important work of the production enterprise. The above analysis shows that the measures to control microbial contamination of pure water should be comprehensive, and can not overemphasize one aspect, while ignoring other aspects, because any part of the production process is contaminated, will affect the quality of the product.
2.1 Strengthen its own health management, strengthen the awareness of food hygiene and quality, designate a leader responsible for health work, set up a full-time health inspection agency, strengthen the water source, packaging, filling room air and product testing, the development of health management system from the management of the water source, sterilization, filling, packaging to the personal hygiene of the various aspects of the health management system, and designate a person to supervise the implementation of the strengthening of the food hygiene knowledge of training and learning
Focus on mastering sterilization methods and clear microbial contamination of key links easily.
2.2 According to the characteristics of the water source, rational and scientific design of the production process, equipped with the necessary water treatment and production equipment, select the sterilization system in line with the water disinfection. At present, China's mineral water and pure water mostly use ultraviolet light, ultrafiltration and ozone as sterilization and disinfection sterilization facilities. But many years of experience has proved that the first two poor reliability, is the main factor causing product failure, and the use of ozone sterilization is considered to be the best method at present.
2.3 Regularly strengthen the production of the whole process of piping, containers and filters and other related facilities to clean and disinfect, do a good job of bottles, caps and filling room disinfection. It is understood that most manufacturers of pipelines and packaging disinfection using chlorine dioxide (ClO2), the drug has a strong oxidation and disinfection, but to strengthen the quality of disinfection drugs to ensure its disinfection effect.
The above hope to help you