Mineral water is a kind of unpolluted underground spring water, which naturally gushes out from deep underground or is exposed artificially.
Mineral water circulates in deep layer, which can prevent external pollution. Rich in mineral essence, trace elements or carbon dioxide gas. In general, its chemical composition, flow rate, water temperature and other dynamics are relatively stable within the natural fluctuation range.
Drinking mineral water contains natural minerals and the limited indicators stipulated by national standards, which must meet the national GB8537 standard. As long as it is mineral water produced according to this standard, it is absolutely healthy and hygienic.
Only the mineral water within the boundary index can be called "drinking" mineral water. Of course, drinking mineral water is natural and one of the healthiest and safest drinking water recognized by international academic circles. Drinking minerals in mineral water is very beneficial to the body and can be drunk for a long time. In addition, drinking mineral water is slightly alkaline, which is suitable for the physiological characteristics of human environment, and is conducive to maintaining normal osmotic pressure and acid-base balance and promoting metabolism.
Because mineral water is naturally pollution-free, it is better to drink normal temperature mineral water directly without heating or freezing as long as it is not "artificially" polluted for the second time. Because mineral water is converted into sediment after boiling, it is harmless to human body from the health point of view, but it wastes these originally beneficial minerals.
Second, boiled water.
Tap water refers to the fresh water in rivers and lakes treated by coagulation, sedimentation, filtration, disinfection and other water purification processes, and finally supplied to users by pumps through water distribution pipelines.
Natural water contains many pathogenic microorganisms. If you drink it directly without disinfection, it may cause the spread of some waterborne diseases. Disinfection of tap water is an essential process in tap water treatment technology, and its purpose is to eliminate microorganisms in water and prevent water-borne diseases.
At present, chlorine disinfection is mostly used for tap water disinfection. Disinfectants include liquid chlorine, bleaching powder, chlorine dioxide, sodium hypochlorite and ozone.
Chlorine is indeed a toxic chemical, but chlorine will only form toxic gas at high concentration, which will cause harm to human body, while chlorine dissolved in water will become hypochlorite, which greatly reduces the harm. At present, studies have proved that the harm caused by insufficient disinfection of drinking water is far greater than that caused by disinfection by-products.
Due to the influence of pipeline structure, especially the materials of water storage tower and pipeline (stainless steel metal pipe, PVC, etc.). ), the water supplied to users by pump through water distribution pipeline often fails to meet the hygienic standard of drinking water.
At the same time, some organic substances will react with disinfectants (such as liquid chlorine) during disinfection to produce toxic substances with carcinogenic, teratogenic and mutagenic effects. Tap water disinfected by chlorine contains halogenated hydrocarbons, chloroform and other 13 harmful substances, such as trihalomethane and haloacetic acid. Although the content of these toxic substances is very small, if you drink tap water directly for a long time, it will cause hidden dangers to your health. It is a good idea to reduce harmful substances to a safe range and boil water.
When the water temperature reaches 90℃, the content of halogenated hydrocarbons rises to 19 1 μ g/L, and chloroform rises to 177 μ g/L, both exceeding the national standard by two times. When the water temperature just reached 100℃, the contents of halogenated hydrocarbons and chloroform were 1 10 μ g/L and 99 μ g/L, respectively. If boiling is continued for 3 minutes, these two substances will rapidly drop to 9.2 micrograms and 8.3 micrograms per liter respectively, reaching the drinking standard. So it is best to boil the water for about 3 minutes.