How to independently check and improve the quality of drinking water. Methods for improving drinking water quality
Methods of water treatment, with the help of which the quality of water from water supply sources is achieved to meet the requirements of SanPiN 2.1.4.2496-09 “Drinking water. Hygienic requirements for water quality of centralized drinking water supply systems. Quality control. Hygienic requirements for ensuring the safety of hot water supply systems” depend on the quality of the source water of water sources and are divided into basic and special. The main methods are: lightening, bleaching, disinfection.
Under lightening And discoloration refers to the removal of suspended substances and colored colloids (mainly humic substances) from water. By disinfection eliminate infectious agents contained in source water - bacteria, viruses, etc.
In cases where the use of only basic methods is not enough, use special cleaning methods(deferrization, defluoridation, desalting, etc.), as well as the introduction of some substances necessary for the human body - fluoridation, mineralization of demineralized and low-mineralized waters.
To remove chemicals, the most effective method is sorption purification using active carbon, which also significantly improves the organoleptic properties of water.
Water disinfection methods are divided into:
- ? to chemical (reagent) ones, which include chlorination, ozonation, and the use of the oligodynamic effect of silver;
- ? physical (reagent-free): boiling, ultraviolet irradiation, gamma ray irradiation, etc.
Due to technical and economic reasons, the main method for disinfecting water at waterworks is chlorination. However, the ozonation method is becoming more and more widely used; its use, including in combination with chlorination, has advantages for improving water quality.
When a chlorine-containing reagent is introduced into water, the bulk of it - more than 95% - is spent on the oxidation of organic and easily oxidized inorganic substances contained in the water. Only 2-3% of the total amount of chlorine is consumed to combine with the protoplasm of bacterial cells. The amount of chlorine that, when chlorinating 1 liter of water, is spent on the oxidation of organic, easily oxidized inorganic substances and disinfection of bacteria within 30 minutes is called chlorine absorption of water. After the process of binding chlorine by substances and bacteria contained in the water is completed, residual active chlorine, which indicates the completion of the chlorination process.
The presence of residual active chlorine in the water supplied to the water supply network in concentrations of 0.3-0.5 mg/l is a guarantee of the effectiveness of water disinfection, is necessary to prevent secondary pollution in the distribution network and serves as an indirect indicator of water safety in epidemic terms.
The total amount of chlorine to satisfy the chlorine absorption of water and provide the required amount (0.3-0.5 mg/l of free active chlorine with normal chlorination and 0.8-1.2 mg/l of combined active chlorine with chlorination with ammoniation) of residual called chlorine chlorine demand of water.
In water treatment practice it is used several methods of chlorination water:
- ? chlorination with normal doses (according to chlorine requirements);
- ? chlorination with preammonization, etc.;
- ? hyperchlorination (the dose of chlorine obviously exceeds the chlorine requirement).
The disinfection process is usually the last stage of water treatment schemes at water supply plants, however, in some cases, when the source water is significantly polluted, double chlorination is used - before and after clarification and discoloration. To reduce the dose of chlorine during final chlorination, combining chlorination with ozonation is very promising.
Chlorination with preammonization. With this method, in addition to chlorine, ammonia is also introduced into the water, resulting in the formation of chloramines. This method is used to improve the chlorination process:
- ? when transporting water through pipelines over long distances (since residual bound - chloramine - chlorine provides a longer bactericidal effect than free);
- ? the content of phenols in the source water, which, when interacting with free chlorine, form chlorophenol compounds, giving the water a strong pharmaceutical smell.
Chlorination with preammonization leads to the formation of chloramines, which, due to their lower redox potential, do not react with phenols, so foreign odors do not arise. However, due to the weaker effect of chloramine chlorine, its residual amount in water should be higher than free, and be at least 0.8-1.2 mg/l.
Ozonation is an effective reagent method for water disinfection. Being a strong oxidizing agent, ozone damages vital enzymes of microorganisms and causes their death. This method improves the taste and color of water. Ozonation does not have a negative effect on the mineral composition and pH of water. Excess ozone is converted into oxygen, so residual ozone is not dangerous to the human body. Ozonation is carried out using special devices - ozonizers. Controlling the ozonation process is less complicated, since the effect does not depend on the temperature and pH of the water.
Since December 2007, a comprehensive technology for disinfecting drinking water with using ultraviolet radiation, combining a high disinfection effect and safety for public health. The economic effect and prevented damage to public health as a result, calculated by the Institute of Medical and Biological Problems and Health Risk Assessment, amounted to 742 million rubles.
Due to the fact that only 1-2% (up to 5 liters per day) a person spends on drinking needs, it is planned to develop and implement two hygienic standards for tap and drinking water - “Water is safe for the population” and “Water of improved quality, beneficial for an adult, physiologically complete.”
The first standard will ensure guaranteed water safety in centralized water supply systems. The second standard will establish specific requirements for “absolutely healthy water” in all its diversity of beneficial effects on the human body. There are a number of options for providing consumers with improved quality water: production of packaged water; installation of local autonomous systems for post-treatment and water quality correction.
The quality of water consumed by modern people often leaves much to be desired. The bad liquid that we drink and cook with is a direct path to various diseases, which is nothing good. What should I do? Various options are available for improving water quality.
First is distillation. The principle of obtaining purified liquid is distillation through a device similar to moonshine - the water boils, evaporates, cools and turns back into ordinary water. It is not recommended to use such water for a long time, as it washes away beneficial substances. It’s quite a hassle to make the distillate yourself, but they say it’s great for fasting days – the body is cleansed very efficiently.
Secondly, you can use water from wells. The main thing is to make sure that the liquid does not contain harmful substances, especially fertilizers and pest control products. Ideally, you still need to carry out a laboratory assessment of the water - it is impossible to find a 100% pure liquid today, and only an experimental method can show what kind of chemistry is in your case.
The third method used to improve liquid performance is settling. During settling, heavy fractions and D2O effectively “leave” (that is, they settle and precipitate), while chlorine is not completely removed, but it is still quite well removed. What’s good about settling is its simplicity and cheapness, but what’s much worse is dubious convenience, long waiting times, and small amounts of water.
The next technique aimed at improving the quality of water resources is infusion on stones containing flint. We are talking directly about flint, as well as chalcedony, amethyst, rock crystal, agate - their special composition allows not only to remove harmful impurities, but also to give the water a number of homeopathic properties. By the way, silicon water effectively enhances the effect of infusions of medicinal herbs. Please note that it is better to take smaller stones, since they have a larger contact area. With constant use, the stones should be soaked in a saline solution and under no circumstances should they be washed under water at a temperature above 40° C. The infusion process takes about a week; it is best to take glass dishes for this purpose, although enamel pans are also suitable. The bottom layer of infused water is not recommended. The resulting liquid does not need to be boiled - it is already suitable for drinking and cooking. Silicon-saturated water has a positive effect on the liver and kidneys, improves metabolic processes, and can be used for weight loss.
Another fairly common “home-grown” method of improving water quality is thawing it. Thawed liquid significantly improves the functioning of organs and systems, the composition of blood and lymph. It is useful for thrombophlebitis, high cholesterol, hemorrhoids, and metabolic problems.
Cleaning with acid, boiling, activated carbon, silver - these are all also working methods that you can use at your discretion.
The most effective and at the same time easy to use are special filters and cleaning systems. A professional consultant will help you find the optimal solution.
Although the flood in the Moscow region after an abnormally snowy winter, as the authorities assured, passed without incident, and the reservoirs are ready for normal operation throughout the year, the quality of water in the Moscow region leaves much to be desired - according to regional authorities, 40% of the water in the water supply does not comply standards How residents can check the quality of the water that flows from their taps at home, independently and in the laboratory, what they need to remember when choosing a filter and what ways there are to improve the quality of water, the correspondent of “In the Moscow Region” found out.
Tea-colored water: risk factors
Drinking water is in fact a much more complex compound than the H2O formula known from chemistry lessons. It may contain a large number of different substances and impurities, and this does not always mean poor quality. The guidelines “Drinking water and water supply to populated areas” of the State System of Sanitary and Epidemiological Standards of the Russian Federation speak of the 68 substances most commonly contained in drinking water. For each of them there is a maximum permissible concentration (MAC), if deviated from, these substances can negatively affect the condition of tooth enamel and mucous membranes, as well as vital human organs: liver, kidneys, gastrointestinal tract and many others. Of course, if you drink a glass of unpurified water, the body will be able to cope with this “micro-poisoning”. But if you consume harmful amounts of substances daily, it can negatively affect your health.
The quality of drinking water is directly affected by human activities. According to the ecologist, head of the laboratory of the Department of Chemistry and Engineering Ecology at FBGOU MIIT, Maria Kovalenko, the main reasons for the deterioration in the quality of drinking water in the Moscow region are:
Development of zones located in a single ecosystem with artesian wells;
Worn-out water supply network: according to the regional housing and communal services construction complex, 36% of networks in the Moscow region are dilapidated, and 40% of water does not meet standards;
Poor condition of treatment facilities: for example, in the Yegoryevsky region, according to the Main Control Department (GKU) of the Moscow Region, treatment facilities in rural settlements are 80% worn out;
Negligent attitude towards industrial waste at many enterprises;
The cost of water analysis, depending on the number of studies required and the laboratory, can range from 1,200 to 3,000 rubles. According to employees of the laboratory of the Department of Chemistry and Engineering Ecology of FBGOU MIIT, the basic analysis of water from wells and water supply networks includes 30 main indicators, including aluminum, iron, manganese, nitrates, nitrites, chlorides, sulfides, etc.
You can also check the quality of the filter using laboratory analysis. To do this, you need to test the water before and after filtration and compare the results.
How to purify water at home: kettle, filter, silver spoons
Experts suggest improving the quality of drinking water at home in several ways. First you need to settle the water: pour water into a container and let it sit for a day, protecting it from dust with a lid.
1. Filtration. Pass the water through any filter containing carbon. This can be a filter jug with a replaceable cassette (average price 400 rubles), a nozzle for a faucet (costs approximately 200-700 rubles) and a filter for a riser (their installation will cost 2 thousand rubles and more). Each of them has its own advantages, but it is important to remember that the last two options will not suit all homes. For example, older buildings may have problems with reduced water pressure and worn-out pipes, so a filter is unlikely to help.
2. Boiling. To boil water, use a regular kettle, not an electric one: the water will boil more slowly, but there will be much less scale.
3. Cleansing with silver. Even an ordinary silver spoon dipped into a reservoir of water can improve its properties.
4. Water disinfection with ultraviolet light or ozonation. When water comes into contact with ozone and UV radiation, bacteria and viruses are destroyed. For this purpose, you can purchase special installations. Before choosing a specific filter for an apartment or an entire entrance, it is better for residents to consult with a specialist.
The Moscow region will be brought to "Clean Water"
It is obvious that the problem of water purification needs to be approached not only at the level of an individual apartment, but also on a regional scale. Since 2013, the Moscow region has been implementing a long-term target program “Clean Water in the Moscow Region”, which is designed for 2013-2020. It is aimed at improving the quality of drinking water, purifying wastewater to standard levels and reducing the risk to public health. The project is now being approved by the Ministry of Finance of the Moscow Region and the Tariff Committee, and it is possible that as early as next year there will be changes at the global level in the situation with poor-quality drinking water.
Svetlana KONDRATIEVA
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Hygiene as a branch of medicine that studies the connection and interaction of the body with the environment is closely related to all disciplines that ensure the formation of a doctor’s hygienic worldview: biology, physiology, microbiology, and clinical disciplines. This makes it possible to widely use the methods and data of these sciences in hygienic research in order to study the influence of environmental factors on the human body and develop a set of preventive measures. The hygienic characteristics of environmental factors and data on their impact on health, in turn, contribute to a more informed diagnosis of diseases and pathogenetic treatment.
Lecture 16. Methods for improving water quality
1. Methods used to improve water quality. Cleaning
To ensure that the water quality meets hygienic requirements, pre-treatment is used. Improving the properties of water with centralized water supply is achieved at waterworks. To improve water quality, use the following:
Cleaning – removal of suspended particles;
Disinfection – destruction of microorganisms;
Special methods for improving organoleptic properties - softening, removal of chemicals, fluoridation, etc.
Cleaning is carried out by mechanical (settling), physical (filtration) and chemical (coagulation) methods.
Settlement, during which clarification and partial discoloration of water occurs, is carried out in special structures - settling tanks. The principle of their operation is that when water enters through a narrow opening and moves slowly in the sump, the bulk of suspended particles settles to the bottom. However, the smallest particles and microorganisms do not have time to settle.
Filtration is the passage of water through a finely porous material, most often through sand with a certain particle size. By filtering, the water is freed from suspended particles.
Coagulation is a chemical cleaning method. A coagulant is added to the water, which reacts with the bicarbonates in the water. This reaction produces large, heavy flocs that carry a positive charge. As they settle under their own weight, they carry with them suspended pollutant particles that are negatively charged.
Aluminum sulfate is used as a coagulant. To improve coagulation, high-molecular flocculants are used: alkaline starch, activated silicic acid and other synthetic preparations.
2. Disinfection. Special methods for improving organoleptic properties
Disinfection destroys microorganisms at the final stage of water treatment. For this purpose, chemical and physical methods are used.
Chemical (reagent) disinfection methods are based on adding various chemicals to water that cause the death of microorganisms. Various strong oxidizing agents can be used as reagents: chlorine and its compounds, ozone, iodine, potassium permanganate, some salts of heavy metals, silver.
Chemical disinfection methods have a number of disadvantages, which include the fact that most reagents negatively affect the composition and organoleptic properties of water.
Reagent-free or physical methods do not affect the composition and properties of disinfected water and do not impair its organoleptic properties. They act directly on the structure of microorganisms, as a result of which they have a wider range of bactericidal effects.
The most developed and technically studied method is irradiation of water with bactericidal (ultraviolet) lamps. Radiation sources are low-pressure argon-mercury lamps (BUV) and mercury-quartz lamps (PRK and RKS).
Of all the physical methods of water disinfection, boiling is the most reliable, but is not widely used.
Physical methods of disinfection include the use of pulsed electric discharge, ultrasound and ionizing radiation.
There is also no practical application.
Deodorization – removal of foreign odors and tastes. For this purpose, methods such as ozonation, carbonization, chlorination, treatment with potassium permanganate, hydrogen peroxide, fluoridation through filters, and aeration are used.
Water softening is the removal of calcium and magnesium cations from it. Produced with special reagents or using ion exchange and thermal methods.
Desalination of water is achieved by distillation in desalination plants, as well as by electrochemical methods and freezing.
Iron removal is carried out by aeration followed by settling, coagulation, liming, cationization, and filtration through sand filters.
An effective method of disinfecting water in a well is the use of chlorine-containing dosing cartridges, which are suspended below the water level.
3. Sanitary protection zones for water sources
Sanitary legislation provides for the organization of two zones of sanitary protection of water sources.
The strict security zone includes the territory where the intake site, water-lifting devices, head structures of the station and the water supply canal are located. This area is fenced and strictly guarded.
The restriction zone includes an area intended to protect water supply sources from contamination (the source of the water supply and the basin for its supply).
Physical and chemical indicators of water quality. When choosing a water supply source, the physical properties of water such as temperature, smell, taste, turbidity and color are taken into account. Moreover, these indicators are determined for all characteristic periods of the year (spring, summer, autumn, winter).
The temperature of natural waters depends on their origin. In underground water sources, the water has a constant temperature regardless of the period of the year. On the contrary, the water temperature of surface water sources varies over periods of the year in a fairly wide range (from 0.1 °C in winter to 24-26 °C in summer).
The turbidity of natural waters depends, first of all, on their origin, as well as on the geographical and climatic conditions in which the water source is located. Groundwater has insignificant turbidity, not exceeding 1.0-1.5 mg/l, but water from surface water sources almost always contains suspended substances in the form of tiny parts of clay, sand, algae, microorganisms and other substances of mineral and organic origin. However, as a rule, the water of surface water sources in the northern regions of the European part of Russia, Siberia and part of the Far East is classified as low-turbidity. On the contrary, water sources in the central and southern regions of the country are characterized by higher water turbidity. Regardless of the geographical, geological and hydrological conditions of the location of the water source, the turbidity of water in rivers is always higher than in lakes and reservoirs. The greatest turbidity of water in water sources is observed during spring floods, during periods of prolonged rain, and the lowest in winter, when water sources are covered with ice. The turbidity of water is measured in mg/dm3.
The color of water from natural water sources is due to the presence in it of colloidal and dissolved organic substances of humic origin, which give the water a yellow or brown tint. The thickness of the shade depends on the concentration of these substances in the water.
Humic substances are formed as a result of the decomposition of organic substances (soil, plant humus) to simpler chemical compounds. In natural waters, humic substances are represented mainly by organic humic and fulvic acids, as well as their salts.
Color is characteristic of water from surface water sources and is practically absent in groundwater. However, sometimes groundwater, most often in swampy low-lying areas with reliable aquifers, becomes enriched with swampy colored waters and acquires a yellowish color.
The color of natural waters is measured in degrees. According to the level of water color, surface water sources can be low color (up to 30-35°), medium color (up to 80°) and high color (over 80°). In water supply practice, water sources are sometimes used whose water color is 150-200°.
Most rivers in the North-West and North of Russia belong to the category of high-color, low-turbidity rivers. The middle part of the country is characterized by water sources of medium color and turbidity. The water of rivers in the southern regions of Russia, on the contrary, has increased turbidity and relatively low color. The color of water in a water source changes both quantitatively and qualitatively over periods of the year. During times of increased runoff from areas adjacent to the water source (melting snow, rain), the color of the water, as a rule, increases, and the ratio of the color components also changes.
Natural waters are characterized by such quality indicators as taste and smell. Most often, natural waters can have a bitter and salty taste and almost never sour or sweet. An excess of magnesium salts gives water a bitter taste, and sodium salts (table salt) give it a salty taste. Salts of other metals, such as iron and manganese, give water a ferrous taste.
Water odors can be of natural or artificial origin. Natural odors are caused by living and dead organisms and plant debris in water. The main odors of natural waters are marshy, earthy, woody, grassy, fishy, hydrogen sulfide, etc. The most intense odors are inherent in the water of reservoirs and lakes. Odors of artificial origin arise due to the release of insufficiently treated wastewater into water sources.
Odors of artificial origin include petroleum, phenolic, chlorophenol, etc. The intensity of tastes and odors is assessed in points.
Chemical analysis of the quality of natural water is of paramount importance when choosing a method for its purification. Chemical indicators of water include: active reaction (hydrogen indicator), oxidability, alkalinity, hardness, concentration of chlorides, sulfates, phosphates, nitrates, nitrites, iron, manganese and other elements. The active reaction of water is determined by the concentration of hydrogen ions. It expresses the degree of acidity or alkalinity of water. Typically, the active reaction of water is expressed by the pH value, which is the negative decimal logarithm of the concentration of hydrogen ions: - pH = - log. For distilled water, pH = 7 (neutral environment). For a slightly acidic pH environment< 7, а для слабощелочной рН >7. Typically, for natural waters (surface and underground), the pH value ranges from 6 to 8.5. Highly colored soft waters have the lowest pH values, while underground waters, especially hard ones, have the highest.
The oxidation of natural waters is caused by the presence of organic substances in them, the oxidation of which consumes oxygen. Therefore, the value of oxidability is numerically equal to the amount of oxygen used to oxidize the pollutants in the water, and is expressed in mg/l. Artesian waters are characterized by the lowest oxidizability (~1.5-2 mg/l, O 2). The water of clean lakes has an oxidability of 6-10 mg/l, O 2; in river water, the oxidability varies widely and can reach 50 mg/l or even more. Highly colored waters are characterized by increased oxidability; in swampy waters, oxidation can reach 200 mg/l O 2 or more.
The alkalinity of water is determined by the presence in it of hydroxides (OH") and carbonic acid anions (HCO - 3, CO 3 2,).
Chlorides and sulfates are found in almost all natural waters. In groundwater, the concentrations of these compounds can be very significant, up to 1000 mg/l or more. In surface water sources, the content of chlorides and sulfates usually ranges from 50-100 mg/l. Sulfates and chlorides at certain concentrations (300 mg/l or more) cause corrosiveness of water and have a destructive effect on concrete structures.
The hardness of natural waters is due to the presence of calcium and magnesium salts in them. Although these salts are not particularly harmful to the human body, their presence in significant quantities is undesirable, because water becomes unsuitable for household needs and industrial water supply. Hard water is not suitable for feeding steam boilers; it cannot be used in many industrial processes.
Iron in natural waters is found in the form of divalent ions, organomineral colloidal complexes and fine suspension of iron hydroxide, as well as in the form of iron sulfide. Manganese, as a rule, is found in water in the form of divalent manganese ions, which can be oxidized in the presence of oxygen, chlorine or ozone to tetravalent, forming manganese hydroxide.
The presence of iron and manganese in water can lead to the development of ferrous and manganese bacteria in pipelines, the waste products of which can accumulate in large quantities and significantly reduce the cross-section of water pipes.
Of the gases dissolved in water, the most important from a water quality point of view are free carbon dioxide, oxygen and hydrogen sulfide. The carbon dioxide content in natural waters ranges from several units to several hundred milligrams per liter. Depending on the pH value of the water, carbon dioxide occurs in it in the form of carbon dioxide or in the form of carbonates and bicarbonates. Excess carbon dioxide is very aggressive towards metal and concrete:
The concentration of oxygen dissolved in water can range from 0 to 14 mg/l and depends on a number of reasons (water temperature, partial pressure, degree of water contamination with organic substances). Oxygen intensifies the corrosion processes of metals. This must be especially taken into account in thermal power systems.
Hydrogen sulfide, as a rule, enters water as a result of its contact with rotting organic residues or with certain minerals (gypsum, sulfur pyrites). The presence of hydrogen sulfide in water is extremely undesirable for both domestic and industrial water supplies.
Toxic substances, in particular heavy metals, enter water sources mainly with industrial wastewater. When there is a possibility of their entry into a water source, determining the concentration of toxic substances in the water is mandatory.
Requirements for water quality for various purposes. The basic requirements for drinking water presuppose that the water is harmless to the human body, has a pleasant taste and appearance, as well as suitability for household needs.
The quality indicators that drinking water must satisfy are standardized by “Sanitary Rules and Norms (SanPiN) 2. 1.4.559-96. Drinking water."
Water for cooling units of many production processes should not form deposits in the pipes and chambers through which it passes, since deposits impede heat transfer and reduce the cross-section of the pipes, reducing the cooling intensity.
There should be no large suspended matter (sand) in the water. There should be no organic substances in the water, as it intensifies the process of biofouling of the walls.
Water for steam power facilities should not contain impurities that can cause scale deposits. Due to scale formation, thermal conductivity decreases, heat transfer deteriorates, and overheating of the walls of steam boilers is possible.
Of the salts that form scale, the most harmful and dangerous are CaSO 4, CaCO 3, CaSiO 3, MgSiO 3. These salts are deposited on the walls of steam boilers, forming boiler stone.
To prevent corrosion of the walls of steam boilers, the water must have a sufficient alkaline reserve. Its concentration in boiler water should be at least 30-50 mg/l.
Particularly undesirable is the presence of silicic acid SiO 2 in the feed water of high-pressure boilers, which can form dense scale with very low thermal conductivity.
Basic technological schemes and structures for improving water quality.
Natural waters are different big variety of contaminants and their combinations. Therefore, to solve the problem of effective water purification, various technological schemes and processes are required, as well as various sets of structures for the implementation of these processes.
Technological schemes used in water treatment practice are usually classified into reagent And reagent-free; pre-treatment And deep cleaning; on single stage And multi-stage; on pressure And free-flow.
The reagent scheme for purifying natural waters is more complex than the non-reagent scheme, but it provides deeper purification. The reagent-free scheme is usually used for pre-treatment of natural waters. Most often it is used in water purification for technical purposes.
Both reagent and non-reagent technological purification schemes can be single-stage or multi-stage, with non-pressure and pressure-type facilities.
The main technological schemes and types of structures most often used in water treatment practice are presented in Figure 22.
Sedimentation tanks are used mainly as structures for preliminary purification of water from suspended particles of mineral and organic origin. Depending on the type of construction and the nature of water movement in the structure, sedimentation tanks can be horizontal, vertical or radial. In recent decades, in the practice of purifying natural waters, special shelf sedimentation tanks with sedimentation of suspended matter in a thin layer have begun to be used.
Rice. 22.
a) two-stage with a horizontal settling tank and filter: 1 - pumping station I lift; 2 - microgrids; 3 - reagent management; 4 - mixer; 5 - flocculation chamber; b - horizontal settling tank; 7 - filter; 8 - chlorination; 9 - clean water tank; 10 - pumps;
b) two-stage with clarifier and filter: 1 - pumping station I lift; 2 - microgrids; 3 - reagent management; 4 - mixer; 5 - suspended sediment clarifier; b - filter; 7 - chlorination; 8 - clean water tank; 9 - II lift pumps;
V) single-stage with contact clarifiers: 1 - pumping station I lift; 2 - drum nets; 3 - reagent management; 4 - restriction device (mixer); 5 - contact clarifier KO-1; 6 - chlorination; 7 - clean water tank; 8 - II lift pumps
Filters, which are part of the general technological scheme of water treatment, act as structures for deep purification of water from suspended substances, some of the colloidal and dissolved substances that have not settled in the settling tanks (due to the forces of adsorption and molecular interaction).
