Maanshan No.4 Waterworks

Tap water is made by tap water workers through multiple technological processes. First of all, the source water must be pumped from rivers and lakes to water plants. Of course, the water intake is different in different regions, and the water source directly affects the quality of drinking water in a region. Then after precipitation, filtration, disinfection and storage (pool cleaning), it is pumped into the tap water pipeline at high pressure by the water pump. Now the state stipulates that the commonly used iron pipe will be replaced by PP pipe, because the iron pipe will rust for a long time and will cause serious secondary pollution; Finally, it is diverted to the user's faucet. The whole process has to go through many water quality tests, and some places have to go through secondary pressurization and secondary disinfection before they can enter the user's home.

At present, most tap water is chlorinated. The main purpose of chlorination of public water supply is to prevent water-borne diseases. This method has been popularized for more than 100 years, and it has relatively perfect production technology and equipment. Chlorine used for disinfection of tap water has the advantages of good disinfection effect, low cost and almost no harmful substances. However, after understanding and studying the theoretical data, we think that chlorine still has some disadvantages in disinfection of tap water. Chlorinated tap water will produce carcinogens, and relevant experts have put forward many improvement measures.

Chlorination disinfection was used about 100 years ago, and it has become a routine disinfection method since then. But with the development of science and technology, some regrettable results have been found in chlorinated tap water! What substance will chlorinated water produce? Will these substances affect human health? How can I get clean and safe drinking water?

At present, disinfectants include chlorine dioxide and ozone in addition to chlorine. The use of alternative disinfectants can reduce the generation of harmful substances and improve the treatment efficiency.

The filtered water should be disinfected with chlorine as disinfectant. Chlorine gas is easily soluble in water and combines with water to generate hypochlorous acid and hydrochloric acid. The main function of chlorine gas in the whole disinfection process is hypochlorous acid. For inorganic substances with peculiar smell, they can be thoroughly oxidized and disinfected. For algae, bacteria and other living natural substances, they can penetrate the cell wall, oxidize their enzyme systems (enzymes are biocatalysts), inactivate them, hinder the life activities of bacteria and die. Hypochloric acid itself is neutral and easy to get close to bacteria, showing good bactericidal effect. Hypochlorite ion also has a certain disinfection effect, but it is difficult to get close to negatively charged bacteria (negatively charged bacteria), so its disinfection effect is much worse than hypochlorous acid, so chlorine disinfection effect is better than bleaching powder disinfection.

At present, the safe disinfection method of tap water in the world is ozone disinfection, but the treatment cost of this method is too expensive, and the retention time of water after ozone treatment is limited. As for how long it can be kept, there is no exact concept at present. So at present, only a few developed countries adopt this treatment method.

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