The water purification process of waterworks is introduced in detail.

1. (Alum added) After the natural water (source water) enters the water plant, it directly enters the reactor pool, and at the same time, water purifying agent (alum) or activated carbon powder can be added for mixing.

2. (Controlling PH) If the PH of water is too low or too high, it is necessary to add neutralizer to control the PH of water at around 7 ~ 8.

3. (Precipitation) After passing through the reaction tank, the water purifying agent and the source water are fully mixed and flow into the sedimentation tank to precipitate impurities to the bottom.

4. (filtration) At this time, most impurities have settled, and water will flow like a filter pool. The filter pool is generally filtered by several layers of sand with different thicknesses, and some processes will use activated carbon to filter.

5. (Adsorption) The "adsorption" mentioned by the landlord should refer to "ion adsorption", which is generally used to soften hard water. If the water source is soft enough, it can be dispensed with.

6, (sterilization) is generally chlorine (some use ozone). Then enter the clear water pool.

7. (Turn into tap water) The pump room pumps the water from the clear water pool into the tap water pipe, which is tap water.

Extended data:

Disinfection method of tap water

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, it is found that chlorine still has some disadvantages in disinfection of tap water. Chlorinated tap water will produce carcinogens. At present, relevant experts have put forward many improvement measures.

Chlorine is dissolved in water and reacts with water to produce hypochlorous acid and hydrochloric acid, and hypochlorous acid plays a major role in the whole disinfection process. 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 close to neutrality, easy to approach 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, 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.

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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