How to deal with impurity deposition in water quality in Mali, Africa

Refers to water whose hardness (mainly calcium and magnesium ions in water) has been removed or reduced to a certain degree. In the process of water softening, it only softens the water, but it can't improve the water quality. Water without softening can easily lead to acclimatization, vomiting and diarrhea.

2. Distillation

Is to boil water, then collect steam, cool it and condense it into liquid. Distilled water is extremely safe drinking water, but there are some problems to be further discussed. Distilled water is strongly opposed by many health experts because it contains no minerals and has extremely low oxygen content. In addition, distillation has high cost and energy consumption, and it can't remove volatile substances from water.

3. Boiling method

It refers to drinking tap water after boiling, which is an ancient method and widely used in China. Boiling water can sterilize, but it cannot remove some chemicals and heavy metals. Moreover, tap water contains a small amount of chlorine gas for sealing, which produces chloroform when boiling, which is extremely harmful to human body. Even if its content is extremely low, it is still very harmful to drink for a long time.

4. Magnetization method

It refers to the treatment of water by magnetic field effect, which is called magnetization treatment of water. The process of magnetization is that water passes through the magnet in the direction perpendicular to the magnetic field lines, that is, the process of magnetization is completed. China's magnetized water treatment technology is still in the initial stage of practice and research, and the deepest research abroad is in Japan. Because there is no scientific consideration for water magnetization in China, magnetized water is not within the scope of pure water, but is included in medical care.

5. Mineralization method

It refers to adding mineral elements (such as calcium, zinc, strontium and other elements) beneficial to human body to water on the basis of purification. Commercially available water purifiers generally add medical stone to the water purifier to achieve the purpose of mineralization. In order to prevent some unscrupulous merchants from exaggerating publicity and causing market confusion, the Ministry of Health has clearly pointed out that "wading products are not allowed to publicize any health care function", and consumers who need health care can only look at the introduction of filter elements in many products to see if they meet the demand.

6. Ozone and ultraviolet sterilization

These aspects can only be sterilized, and heavy metals and chemicals in water cannot be removed. After being killed, the bacteria remains in the water and becomes a pyrogen.

7. Electrolysis

The electrolysis of pure water began in Japan. This equipment is called electrolyzer. It first purifies water and then carries out electrolytic activation. Its alkaline activated water corresponds to the PH value of human internal environment, which is healthy for human body and suitable for drinking. Acidic activated water can be used for washing face and bathing, and has cosmetic effect. However, the benefits of electrolyzed water to human body need further discussion.

8. Activated carbon adsorption

Can be divided into the following three forms

8. 1 granular activated carbon is commonly used, and it is mostly made of carbon-containing substances such as essence, coal quality and fruit shell (core) by chemical method or physical activation method. It has a large number of micropores and specific surface area, so it has strong adsorption capacity and can effectively adsorb organic pollutants in water. In addition, during the activation process, some oxygen-containing functional groups are formed in the amorphous part of the surface of activated carbon, which makes the activated carbon have chemical adsorption, catalytic oxidation and reduction properties, and can effectively remove some metal ions from water.

8.2 Silver-infiltrated activated carbon combines activated carbon with silver, which not only absorbs organic pollutants in water, but also has bactericidal effect, and bacteria will not grow in activated carbon, thus solving the problem of high nitrite content in effluent of water purifier. When water passes through activated carbon impregnated with silver, it will slowly release silver ions, which will play a role in disinfection and sterilization. Activated carbon has a good effect on removing color, odor, chlorine, iron, arsenic, mercury, cyanide, phenol, etc. in water, and its sterilization effect is above 90%, so it is used in small water purifiers.

8.3 Fiber Activated Carbon Organic carbon fiber is a new adsorption material formed by activation treatment, which has developed micropore structure, huge specific surface area and numerous functional groups. Foreign countries have made remarkable achievements in solvent recovery and gas purification by using fiber activated carbon. A lot of research work has also been done in the application of water treatment.

9.RO reverse osmosis membrane

RO reverse osmosis is a popular international machine (also known as terminal water purification equipment) that filters raw water (physical method) by reverse osmosis and directly produces pure water for human consumption. Municipal tap water whose water quality meets the Hygienic Standard for Drinking Water Quality (200 1) issued by the Ministry of Health of China is used as raw water. The raw water is pre-filtered by two activated carbon filter elements (1 granular activated carbon, 1 sintered activated carbon) and 1 PPF spray filter elements, and then the pre-filtered water is forced to pass through RO (reverse osmosis) with a pore size of one ten thousandth of a micron. English reverse osmosis) membrane, and finally the pH value of water is adjusted by silver-loaded activated carbon (also called small T33) made of fruit shell (coconut shell) (to make the prepared purified water taste sweet and mellow), so as to prepare purified water. RO reverse osmosis water purifier introduces advanced ultra-low pressure reverse osmosis technology and accessories from the United States, and produces the most advanced purified water device for household and group use in China. The device produces high-quality water, which is safe, stable and reliable in operation, simple in operation and small in occupied area, and can most effectively remove calcium, magnesium, bacteria, organic matter, inorganic matter, metal ions and radioactive substances in water. The water purified by this device is clear and sweet. The device is suitable for families, hotels, hotels, hospitals and other enterprises and institutions to drink clean water.

Compared with bottled water, the purified water produced by RO reverse osmosis water purification mechanism is fresher, more hygienic and safer. It has a wide range of uses: it can be drunk raw or boiled. The most prominent feature in this respect is that the kettle or electric thermos will never scale again. Pure water for cooking is more hygienic and delicious; Bathing with pure water can remove impurities from the skin, moisturize the skin and play a natural beauty effect; It can provide water for small household appliances such as humidifier, steam iron and beauty instrument. And there will never be an annoying scale; When used together with an ice maker, the ice cubes made are crystal clear without any peculiar smell.

Reverse osmosis: Reverse osmosis was originally developed by NASA with the support of the government. It cost billions of dollars and has been studied for many years. The principle of reverse osmosis is to apply a pressure greater than the natural osmotic pressure on the raw water side, so that water molecules can reverse permeate from the high concentration side to the low concentration side. Because the pore size is much smaller than hundreds or even thousands of times that of case virus and bacteria, all kinds of viruses, bacteria, heavy metals, solid soluble substances, polluted organic substances and calcium and magnesium ions can not pass through the reverse osmosis membrane at all, thus achieving the purpose of softening and purifying water quality.

10. microfiltration and ultrafiltration

It is a microporous filter membrane made of cellulose or polymer materials, which uses its uniform pore size to intercept particles, bacteria, colloids and so on. In water, so that they can be removed without a filter membrane. This microporous membrane filtration technology, also known as particle density filtration technology, can filter micron or nano particles and bacteria. Ultrafiltration and microfiltration are both membrane separation technologies, and there is no obvious boundary between them. The working pressure of ultrafiltration is generally about 0.3 MPa, which can remove macromolecular substances, bacteria, viruses, etc. from water, but the flux is low.

1 1, hydrogen-rich (negative) method

Using electrolysis technology, hydrogen is generated, while a small amount of hydrogen dissolved in water generates H3O+. As a non-toxic and harmless inert gas, hydrogen will not cause any harm to human body, while hydrogen and a small amount of H3O+ dissolved in water will react with reactive oxygen radicals harmful to human body to generate water. Hydrogen-rich method originated from Japanese technology, and other countries have not studied it enough. There is little research on this block in China, and the deepest one is Shizhen Hydraulic Institute, where retired Professor Song Hongchang of Chinese Academy of Sciences is located. Some technologies have surpassed those of Japan. Although hydrogen-rich technology is of great significance, its application is extremely narrow at present. The water used in hydrogen-rich technology must be compound purified water, which must contain minerals in addition to being clean. Previously, the water used for hydrogen-rich technology in Japan still needed to be below 60℃. With the establishment of a special water research institute in China, the research team led by Professor Song Hongchang has been able to use hot water to enrich hydrogen.

12. Composite type

When one process is difficult to remove harmful substances from water, two or more processes are adopted, which is called compounding. Like activated carbon adsorption? Ultraviolet sterilization and activated carbon adsorption? Reverse osmosis, activated carbon adsorption? Microfiltration (ultrafiltration), polypropylene microfiber? Live charcoal? Microfiltration (ultrafiltration), etc. Among the composite water purifiers, the membrane technology composite water purifier has excellent water purification performance, especially in removing microorganisms (bacteria, algae and so on). ). Some excellent water purifiers can directly drink raw water, which has been welcomed by consumers and has become a hot spot in the development of water purifiers.

The design and manufacture of water purifier is a comprehensive science and technology. The design principle of water purifier should be for the sake of users. As far as the characteristics of water quality in various regions of China are concerned, the organic pollution along the Yangtze River and densely populated areas is serious, while the problem of bacterial pollution exists in small water supply enterprises and groundwater use areas in villages and towns all over the country. Therefore, only some high-quality water purifiers can adapt to different water quality in different parts of the country, so water purifier manufacturers should carefully design water purifiers that can adapt to different water sources but have good treatment effect according to the water quality situation in different areas.

In short, the water purifier is related to the drinking water safety and health of millions of people. Therefore, the quality of the water purifier itself and the quality of the effluent must be paid attention to by manufacturers, and advanced technology and equipment should be continuously absorbed and adopted to continuously improve the quality of the water purifier to meet the growing consumer demand of the people.

Coagulant for removing suspended colloid In order to remove suspended clay and colloid in water, coagulant needs to be added. Fine dispersed clay colloid is difficult to separate from water by gravity sedimentation alone. The function of coagulant is to make fine clay particles gather together through adsorption to form aggregates with a diameter of 65438 0 μ m, and then further make the aggregates aggregate into wool-like flocs through chemical bonding and coprecipitation. Floccules can be removed by settling under the action of gravity. ?

Ion exchange method mainly removes the hardness (Ca2+, Mg2+) of water, but does not remove all strong electrolytes including non-hardness salts. Moreover, there are weak electrolytes such as silicic acid and impurities such as gas, colloid, organic matter and bacteria in the water. According to the removal degree of these impurities, pure water can be divided into desalted water, pure water and ultrapure water.

Ultra-pure water manufacturing system usually consists of the following steps. ?

(1) pretreatment? Objective To reduce the load of subsequent treatment steps, including coagulation and sedimentation, precision filtration and activated carbon adsorption layer filtration, so as to remove coarse impurities contained in water. ?

(2) ion exchange treatment? Various soluble ionic impurities are removed by ion exchange resin to remove other non-hard electrolyte ions except calcium and magnesium ions; Sometimes it is necessary to add high-performance ion exchange devices; ?

(3) Ultrafiltration membrane treatment? The purpose is to remove all kinds of tiny impurities (including bacteria and organic residues) suspended in water. ?

(4) Reverse osmosis treatment? Remove smaller soluble impurities (such as soluble proteins) that ultrafiltration membranes cannot remove. It should be noted that the semi-permeable membrane used in reverse osmosis treatment process has short pressure life+the load of this semi-permeable membrane should be reduced as much as possible.

(5) UV lamp treatment? Ultraviolet rays killed microorganisms in buffalo. ?

Water treatment equipment is a process of removing some harmful substances in water that are not needed for production and life by physical, chemical and biological means. It is a process of water quality regulation such as sedimentation, filtration, coagulation, flocculation, corrosion inhibition and scale inhibition for a specific purpose. Because social production and life are closely related to water. Therefore, the field of water treatment involves a wide range of applications, which constitutes a huge industrial application.

Water treatment equipment includes sewage treatment and drinking water treatment. In some places, sewage treatment is further divided into two types, namely sewage treatment and reclaimed water reuse. Commonly used water treatment agents are: polyaluminum chloride, polyaluminum ferric chloride, basic aluminum chloride, polyacrylamide, activated carbon and various filter materials.

The effect of water treatment equipment can be measured by water quality standards. Treatment of raw water (raw water) to meet the water quality requirements of finished water (domestic water, production water or dischargeable wastewater). When the treated raw water is domestic water or industrial water, it is called water supply treatment. When water treatment equipment treats wastewater, it is called wastewater treatment. The purpose of wastewater treatment is to treat waste.

Discharge (into water or land) or water reuse (see wastewater treatment and wastewater reuse).

In the circulating water system and water regeneration treatment, the raw water is wastewater, and the factory water is water. The treatment process has the nature of water supply treatment and wastewater treatment. Water treatment also includes the treatment and final disposal of wastewater and sludge generated in the treatment process (see sludge treatment and disposal), and sometimes it also includes the treatment and discharge of waste gas. Water treatment methods can be summarized into three ways: ① The most common way is to get the required water quality by removing some or all impurities in raw water; (2) Adding new components into raw water, the required water quality can be obtained in the later stage through physical or chemical reaction; ③ The treatment of raw water does not involve removing impurities or adding new components.

Impurities in water of water treatment equipment include coarse substances, suspended solids, colloids and dissolved substances. Floating aquatic plants, garbage, large aquatic organisms, gravel in wastewater, large pieces of dirt and other coarse substances. In the water supply project, coarse impurities are removed by the facilities of water intake structures, which are not included in the water treatment scope.