Methods for improving water quality make it possible to free water from microorganisms, suspended particles, excess salts, foul-smelling gases. They are divided into 2 groups: basic and special.

Basic: cleaning and disinfection.

Hygienic requirements for the quality of drinking water are set out in the Sanitary Rules “Drinking Water. Hygienic….” (2001).

- Cleaning. The goal is to get rid of suspended particles and colored colloids to improve the physical properties (transparency and color). Cleaning methods depend on the source of the water supply. Underground interstratal water sources require less cleaning. The water of open reservoirs is subject to pollution, so they are potentially dangerous.

Purification is achieved by three activities:

- settling: after the passage of water from the river through the intake grids, in which large pollutants remain, the water enters large tanks - settling tanks, with a slow flow through which in 4-8 hours. large particles fall to the bottom.

- coagulation: to settle small suspended solids, water enters the tanks, where it is coagulated - polyacrylamide or aluminum sulfate is added to it, which, under the influence of water, becomes flakes, to which small particles adhere and dyes are adsorbed, after which they settle to the bottom of the tank.

- filtration: water is slowly passed through a layer of sand and a filter cloth or other (slow and fast filters) - the remaining suspended solids, helminth eggs and 99% of the microflora are retained here. The filters are washed 1-2 times a day with a reverse flow of water.

- Disinfection.

To ensure epidemic safety (destruction of pathogenic microbes and viruses), water is disinfected: by chemical or physical methods.

Chemical Methods : chlorination and ozonation.

BUT) Chlorination in odes with chlorine gas (at large stations) or bleach (at small ones).

The availability of the method, the low cost and reliability of disinfection, as well as the multivariance, i.e. the ability to disinfect water at waterworks, mobile installations, in a well, at a field camp ...

The effectiveness of water chlorination depends on: 1) the degree of purification of water from suspended solids, 2) the injected dose, 3) the thoroughness of water mixing, 4) sufficient exposure of water with chlorine, and 5) the thoroughness of checking the quality of chlorination by residual chlorine.

The bactericidal effect of chlorine is greatest in the first 30 minutes and depends on the dose and water temperature - at low temperatures, disinfection is extended up to 2 hours.

In accordance with sanitary requirements, 0.3-0.5 mg / l of residual chlorine should remain in the water after chlorination (does not affect the human body and organoleptic properties of water).

Depending on the dose used, there are:

Conventional chlorination - 0.3-0.5 mg / l

Hyperchlorination - 1-1.5 mg / l, during the period of epidemic danger. Followed by activated charcoal to remove excess chlorine.

Chlorination modifications:

- double chlorination provides for the supply of chlorine to waterworks twice: before the sedimentation tanks, and the second after the filters. This improves coagulation and discoloration of water, inhibits the growth of microflora in treatment facilities x, increases the reliability of disinfection.

- Chlorination with ammonization provides for the introduction of a solution of ammonia into the disinfected water, and after 0.5-2 minutes - chlorine. At the same time, chloramines are formed in the water, which also have a bactericidal effect.

- Rechlorination provides for the addition of large doses of chlorine to water (10-20 mg / l or more). This allows you to reduce the contact time of water with chlorine to 15-20 minutes and obtain reliable disinfection from all types of microorganisms: bacteria, viruses, rickettsiae, cysts, dysenteric amoeba, tuberculosis.

Water with residual chlorine of at least 0.3 mg/l must reach the consumer

B) Water ozonation method. Currently, it is one of the promising ones (France, USA, in Moscow, Yaroslavl, Chelyabinsk).

Ozone (O3) - causes bactericidal properties and discoloration and elimination of tastes and odors occur. An indirect indicator of the effectiveness of ozonation is the residual ozone at the level of 0.1-0.3 mg/l.

The advantages of ozone over chlorine: ozone does not form toxic compounds (organochlorine compounds) in water, improves the organoleptic properties of water and provides a bactericidal effect with a shorter contact time (up to 10 minutes).

C) Decontamination of individual stocks in methods (chemical and physical) are used at home and in the field:

Oligodynamic action of silver. By using special devices by electrolytic treatment of water. Silver ions have a bacteriostatic effect. Microorganisms stop reproducing, although they remain alive and even capable of causing disease. Therefore, silver is mainly used for preserving water during long-term storage in navigation, astronautics, etc.

To disinfect individual water supplies, tablets containing chlorine are used: Aquasept, Pantocid…..

Boiling (5-30 min), while many chemical contaminants are preserved;

Household appliances - filters providing several degrees of purification;

Physical methods of water disinfection

Advantage over chemical ones: they do not change the chemical composition of water, do not worsen its organoleptic properties. But due to their high cost and the need for careful preliminary water treatment, only ultraviolet irradiation is used in water pipes,

- Boiling (was, cm)

- Ultraviolet (UV) irradiation. Advantages: in the speed of action, the effectiveness of the destruction of vegetative and spore forms of bacteria, eggs of helminths and viruses, does not form a smell and taste. Rays with a wavelength of 200-275 nm have a bactericidal effect.

Introduction

Literature review

1 Requirements for the quality of drinking water

2 Basic methods for improving water quality

2.1 Discoloration and clarification of water

2.1.1 Coagulants - flocculants. Application in water treatment plants

2.1.1.1 Aluminium-containing coagulants

2.1.1.2 Iron coagulants

3 Disinfection of drinking water

3.1 Chemical disinfection

3.1.1 Chlorination

3.1.2 Decontamination with chlorine dioxide

3.1.3 Water ozonation

3.1.4 Water disinfection with heavy metals

3.1.5 Decontamination with bromine and iodine

3.2 Physical method of disinfection

3.2.1 UV disinfection

3.2.2 Ultrasonic disinfection of water

3.2.3 Boiling

3.2.4 Decontamination by filtration

Existing provisions

Setting the goal and objectives of the project

Proposed measures to improve the efficiency of Nizhny Tagil's wastewater treatment facilities

Settlement part

1 Estimated part of existing treatment facilities

1.1 Reagent facilities

1.2 Calculation of mixers and flocculation chambers

1.2.1 Calculation of the vortex mixer

1.2.2 Swirl flocculation chamber

1.3 Calculation of a horizontal sump

1.4 Calculation of fast free-flow filters with double-layer loading

1.5 Calculation of a chlorination plant for dosing liquid chlorine

1.6 Calculation of tanks pure water

2 Estimated part of the proposed treatment facilities

2.1 Reagent facilities

2.2 Calculation of a horizontal sump

2.3 Calculation of fast free-flow filters with double-layer loading

2.4 Calculation of the ozonating plant

2.5 Calculation of sorption carbon filters

2.6 Calculation of installations for water disinfection by bactericidal radiation

2.7 Decontamination of NaClO (commercial) and UV

Conclusion

Bibliographic list

Introduction

Water treatment is a complex process and requires careful thought. There are a lot of technologies and nuances that directly or indirectly affect the composition of water treatment, its power. Therefore, to develop technology, think over equipment, stages should be very carefully. There is very little fresh water on earth. Most of the earth's water resources are salt water. The main disadvantage of salt water is the impossibility of using it for food, washing, household needs, and production processes. To date, there is no natural water that could be immediately used for needs. Household waste, all kinds of emissions into rivers and seas, nuclear storage, all this has an impact on water.

Drinking water treatment is very important. The water that people use in everyday life must meet high quality standards, it must not be harmful to health. Thus, drinking water is pure water that does not harm human health and is suitable for food. To get such water today is costly, but still possible.

The main purpose of drinking water treatment is to purify water from coarse and colloidal impurities, hardness salts.

The aim of the work is to analyze the operation of the existing Chernoistochinsky water treatment plant and propose options for its reconstruction.

Make an enlarged calculation of the proposed water treatment facilities.

1 . Literature review

1.1 Requirements for the quality of drinking water

In the Russian Federation, the quality of drinking water must meet certain requirements established by SanPiN 2.1.4.1074-01 "Drinking Water". In the European Union (EU), the directive "On the quality of drinking water intended for human consumption" 98/83/EC defines the standards. The World Health Organization (WHO) establishes water quality requirements in the 1992 Drinking Water Quality Control Guidelines. There are also regulations of the Agency for Protection environment United States (U.S.EPA) . In the norms, there are slight differences in various indicators, but only water of the appropriate chemical composition ensures human health. The presence of inorganic, organic, biological contaminants, as well as an increased content of non-toxic salts in amounts exceeding those specified in the requirements presented, leads to the development of various diseases.

The main requirements for drinking water are that it must have favorable organoleptic characteristics, be harmless in its chemical composition and safe in epidemiological and radiation terms. Before water is supplied to distribution networks, at water intake points, external and internal water supply networks, the quality of drinking water must comply with the hygienic standards presented in Table 1.

Table 1 - Requirements for the quality of drinking water

Indicators	Units	SanPin 2.1.4.1074-01
Hydrogen indicator
Total mineralization (dry residue)
Chroma
Turbidity	mg/l (for kaolin)	2,6 (3,5) 1,5 (2,0)		no more than 0.1	no more than 0.1
General hardness
Oxidability permanganate
Oil products, total
Phenolic index
Alkalinity	mgHCO - 3 /l
Phenolic index
Aluminum (Al 3+)
Ammonia nitrogen
Barium (Ba 2+)
Beryllium (Be 2+)
Boron (V, total)
Vanadium (V)
Bismuth (Bi)
Iron (Fe, total)
Cadmium (Cd, total)
Potassium (K+)
Calcium (Ca2+)
Cobalt (Co)
Silicon (Si)
Magnesium (Mg2+)
Manganese (Mn, total)
Copper (Cu, total)
Molybdenum (Mo, total)
Arsenic (As, total)
Nickel (Ni, total)
Nitrates (according to NO 3 -)
Nitrites (according to NO 2 -)
Mercury (Hg, total)
Lead (Pb,
Selenium (Se, total)
Silver (Ag+)
Hydrogen sulfide (H 2 S)
Strontium (Sg 2+)
Sulphates (S0 4 2-)
Chlorides (Сl -)
Chromium (Cr 3+)				0.1 (total)
Chromium (Cr 6+)				0.1 (total)
Cyanides (CN -)
Zinc (Zn2+)
s.-t. - sanitary and toxicological; org. - organoleptic

After analyzing the data in the table, one can notice significant differences in some indicators, such as hardness, oxidizability, turbidity, etc.

The safety of drinking water in terms of chemical composition is determined by its compliance with the standards for generalized indicators and the content of harmful chemicals most commonly found in natural waters in the Russian Federation, as well as substances of anthropogenic origin that have become globally widespread (see Table 1).

Table 2 - The content of harmful chemicals entering and forming in water during its treatment in the water supply system

Name of indicator	standard, no more	Harm factor	Hazard Class
Residual free chlorine, mg / dm 3	within 0.3-0.5
Residual chlorine, mg / dm 3	within 0.8-9.0
Chloroform (when chlorinating water), mg / dm 3
Residual ozone, mg / dm 3
Polyacrylamide, mg / dm 3
Activated silicic acid (according to Si), mg / dm 3
Polyphosphates (according to RO 4 3-), mg / dm 3
Residual amounts of coagulants, mg / dm 3

1.2 Basic methods for improving water quality

1.2.1 Water bleaching and clarification

Water clarification refers to the removal of suspended solids. Water decolorization - elimination of colored colloids or true solutes. Clarification and discoloration of water is achieved by settling, filtering through porous materials and coagulation. Very often these methods are used in combination with each other, for example, sedimentation with filtration or coagulation with sedimentation and filtration.

Filtration is due to the retention of suspended particles outside or inside the filtering porous medium, while sedimentation is the process of precipitation of suspended particles into sediment (for this, unclarified water is retained in special settling tanks).

Suspended particles settle under the influence of gravity. The advantage of sedimentation is the absence of additional energy costs when clarifying water, while the flow rate of the process is directly proportional to the particle size. When a reduction in particle size is monitored, an increase in settling time is observed. This dependence is also valid when the density of suspended particles changes. Precipitation is rationally used to isolate heavy, large suspensions.

Filtration can provide in practice any quality for water clarification. But with this method of water clarification, additional energy costs are needed, which serve to reduce the hydraulic resistance of the porous medium, which is capable of accumulating suspended particles and increasing resistance over time. To prevent this, it is desirable to carry out preventive cleaning of the porous material, which is capable of restoring the original properties of the filter.

With an increase in the concentration of suspended solids in water, the required clarification index also increases. The clarification effect can be improved by operating chemical water treatment, which requires the use of auxiliary processes such as: flocculation, coagulation and chemical precipitation.

Decolouration, along with clarification, is one of the initial stages in water treatment in water treatment plants. This process is carried out by settling water in containers with subsequent filtration through sand-charcoal filters. In order to speed up the sedimentation of suspended particles, coagulants-flocculators are added to the water - aluminum sulphate or ferric chloride. To increase the rate of coagulation processes, the chemical preparation polyacrylamide (PAA) is also used, which increases the coagulation of suspended particles. After coagulation, sedimentation and filtration, the water becomes clear and, as a rule, colorless, and the eggs of geohelminths and 70-90% of microorganisms are removed.

.2.1.1 Coagulants - flocculants. Application in water treatment plants

In reagent water purification, aluminum- and iron-containing coagulants are widely used.

1.2.1.1.1 Aluminium-containing coagulants

In water treatment, the following aluminum-containing coagulants are used: aluminum sulfate (SA), aluminum oxychloride (OXA), sodium aluminate and aluminum chloride (Table 3).

Table 3 - Aluminium-containing coagulants

Coagulant
			Insoluble impurities
Aluminum sulfate, crude	Al 2 (SO 4) 18H 2 O
Purified aluminum sulfate	Al 2 (SO 4) 18H 2 O Al 2 (SO 4) 14H 2 O Al 2 (SO 4) 12H 2 O	>13,5 17- 19 28,5
aluminum oxychloride	Al 2 (OH) 5 6H 2 O
sodium aluminate
Aluminum polyoxychloride	Al n (OH) b Cl 3n-m where n>13

aluminum sulfate (Al 2 (SO 4) 3 18H 2 O) is a technically unpurified compound, which is a grayish-greenish fragment obtained by treating bauxites, clays or nephelines with sulfuric acid. It must have at least 9% Al 2 O 3 , which is equivalent to 30% pure aluminum sulfate.

Purified SA (GOST 12966-85) is obtained in the form of plates of a grayish-pearl color from crude raw materials or alumina by dissolving in sulfuric acid. It must contain at least 13.5% Al 2 O 3 , which is equivalent to 45% aluminum sulfate.

In Russia, a 23-25% solution of aluminum sulfate is produced for water purification. When using aluminum sulfate, there is no need for specially designed equipment for dissolving the coagulant, and it also makes handling and transportation easier and more affordable.

At lower air temperatures, when treating water with a high content of natural organic compounds, aluminum oxychloride is used. OXA is known under various names: polyaluminum hydrochloride, aluminum chlorhydroxide, basic aluminum chloride, etc.

The cationic coagulant OXA is capable of forming complex compounds with a large number of substances contained in water. As practice has shown, the use of OXA has a number of advantages:

- OXA - partially hydrolyzed salt - has a high ability to polymerize, which increases flocculation and settling of the coagulated mixture;

– OXA can be used over a wide pH range (compared to CA);

– when coagulating OXA, the decrease in alkalinity is insignificant.

This reduces the corrosiveness of water, improves the technical condition of the city's water pipelines and preserves the consumer properties of water, and also makes it possible to completely abandon alkaline agents, which allows them to be saved at an average water treatment plant up to 20 tons per month;

– with a high input dose of the reagent, a low residual aluminum content is observed;

– reduction of the coagulant dose by 1.5-2.0 times (compared to CA);

– reduction of labor intensity and other costs for the maintenance, preparation and dosing of the reagent, which improves sanitary and hygienic working conditions.

sodium aluminate NaAlO 2 are white solid fragments with a pearlescent sheen at the break, which are obtained by dissolving aluminum hydroxide or oxide in a solution of aluminum hydroxide. Dry commercial product contains 35% Na 2 O, 55% Al 2 O 3 and up to 5% free NaOH. Solubility of NaAlO 2 − 370 g/l (at 200 ºС).

aluminum chloride AlCl 3 is a white powder with a density of 2.47 g / cm 3, with a melting point of 192.40 ºС. AlCl 3 ·6H 2 O is formed from aqueous solutions with a density of 2.4 g/cm 3 . As a coagulant during the flood period at low water temperatures, the use of aluminum hydroxide is applicable.

1.2.1.1.2 Iron coagulants

The following iron-containing coagulants are used in water treatment: iron chloride, iron(II) and iron(III) sulfates, chlorinated ferrous sulfate (Table 4).

Table 4 - Iron-containing coagulants

Ferric chloride (FeCl 3 6H 2 O) (GOST 11159-86) is dark crystals with a metallic luster, has strong hygroscopicity, therefore it is transported in sealed iron containers. Anhydrous ferric chloride is produced by chlorination of steel shavings at a temperature of 7000 ºС, and is also obtained as a secondary product in the manufacture of metal chlorides by hot chlorination of ores. The commercial product must contain at least 98% FeCl 3 . Density 1.5 g/cm 3 .

Iron(II) sulfate (CF) FeSO 4 7H 2 O (iron vitriol according to GOCT 6981-85) are transparent crystals of a greenish-bluish color, which easily turn brown in atmospheric air. As a commercial product, CL is produced in two grades (A and B), which contains, respectively, not less than 53% and 47% FeSO 4 , not more than 0.25-1% free H 2 SO 4 . The density of the reagent is 1.5 g/cm 3 . This coagulant is applicable at pH > 9-10. In order to reduce the concentration of dissolved iron(II) hydroxide at low pH values, the oxidation of ferrous iron to ferric iron is additionally carried out.

Oxidation of iron(II) hydroxide, which is formed during the hydrolysis of SF at water pH less than 8, proceeds slowly, which leads to its incomplete precipitation and coagulation. Therefore, before SF is added to the water, lime or chlorine is additionally added separately or together. In this regard, SF is used mainly in the process of lime and lime-soda water softening, when at a pH value of 10.2-13.2, the removal of magnesium hardness with aluminum salts is not applicable.

Iron(III) sulfate Fe 2 (SO 4) 3 2H 2 O is obtained by dissolving iron oxide in sulfuric acid. The product has a crystalline structure, absorbs water very well, and is highly soluble in water. Its density is 1.5 g / cm 3. The use of iron(III) salts as a coagulant is more preferable than aluminum sulfate. When using them, the coagulation process proceeds better at low water temperatures, the medium has little effect on the pH reaction, the process of decantation of coagulated impurities increases and the settling time is reduced. The disadvantage of using iron(III) salts as coagulants-flocculators is the need for accurate dosing, since its violation causes the penetration of iron into the filtrate. Flakes of iron(III) hydroxide settle unequally, so a certain amount of small flakes remains in the water, which subsequently enters the filters. These faults are removed to some extent by adding a CA.

Chlorinated iron sulfate Fe 2 (SO 4) 3 + FeCl 3 is obtained directly at water treatment plants when processing a solution of ferrous sulfate chlorine.

One of the main positive qualities iron salts as coagulants-flocculators - this is the high density of the hydroxide, which makes it possible to obtain denser and heavier flakes that precipitate at high speed.

Coagulation of wastewater with iron salts is not suitable, since these waters contain phenols, and water-soluble iron phenolates are obtained. In addition, iron hydroxide serves as a catalyst that helps the oxidation of some organics.

Mixed aluminum-iron coagulant obtained in a ratio of 1:1 (by weight) from solutions of aluminum sulfate and ferric chloride. The ratio may vary, based on the operating conditions of the cleaning apparatus. The preference for using a mixed coagulant is an increase in the productivity of water treatment at low water temperatures and an increase in the settling properties of the flakes. The use of a mixed coagulant makes it possible to significantly reduce the consumption of reagents. Mixed coagulant can be added both separately and by initially mixing the solutions. The first method is most preferable when changing from one acceptable proportion of coagulants to another, but the second method is the easiest way to do dosing of the reagent. However, the difficulties associated with the content and manufacture of the coagulant, as well as an increase in the concentration of iron ions in purified water with irreversible changes in the technological process, limit the use of a mixed coagulant.

In some scientific papers note that when using mixed coagulants, in some cases they give a greater result of the process of precipitation of the dispersed phase, a better quality of purification from pollutants and a decrease in the consumption of reagents.

During the intermediate selection of coagulant flocculants for both laboratory and industrial purposes, it is necessary to take into account some parameters:

Purified water properties: pH; dry matter content; the ratio of inorganic and organic substances, etc.

Working mode: reality and fast mixing conditions; the duration of the reaction; settling time, etc.

End results to be assessed: particulate matter; turbidity; color; COD; settling speed.

1.3 Disinfection of drinking water

Disinfection is a set of measures for the destruction of pathogenic bacteria and viruses in water. Disinfection of water according to the method of action on microorganisms can be divided into chemical (reagent), physical (reagentless) and combined. In the first case, biologically active chemical compounds (chlorine, ozone, heavy metal ions) are added to the water, in the second case, physical effects (ultraviolet rays, ultrasound, etc.), and in the third case, both physical and chemical effects are used. Before water is disinfected, it is first filtered and/or coagulated. During coagulation, suspended solids, helminth eggs, and most of the bacteria are eliminated.

.3.1 Chemical decontamination

With this method, it is necessary to correctly calculate the dose of the reagent that is introduced for disinfection, and determine its maximum duration with water. Thus, a persistent disinfecting effect is achieved. The dose of the reagent can be determined based on calculation methods or test decontamination. To achieve the desired positive effect, determine the dose of the excess reagent (residual chlorine or ozone). This guarantees complete destruction of microorganisms.

.3.1.1 Chlorination

The most common application in water disinfection is the method of chlorination. Advantages of the method: high efficiency, simple technological equipment, cheap reagents, ease of maintenance.

The main advantage of chlorination is the absence of re-growth of microorganisms in the water. In this case, chlorine is taken in excess (0.3-0.5 mg / l of residual chlorine).

Parallel to disinfection water is coming oxidation process. As a result of the oxidation of organic substances, organochlorine compounds are formed. These compounds are toxic, mutagenic, and carcinogenic.

.3.1.2 Decontamination with chlorine dioxide

Advantages of chlorine dioxide: antibacterial and deodorizing properties of a high degree, absence of organochlorine compounds, improvement of the organoleptic properties of water, solution of the transport problem. Disadvantages of chlorine dioxide: high cost, complexity in manufacturing and is used in plants of low productivity.

Regardless of the water matrix being treated, the properties of chlorine dioxide are significantly stronger than those of simple chlorine, which is in the same concentration. It does not form toxic chloramines and methane derivatives. From the point of view of smell or taste, the quality of a particular product does not change, and the smell and taste of water disappear.

Due to the acidity reduction potential, which is very high, chlorine dioxide has a very strong effect on the DNA of microbes and viruses, various bacteria in comparison with other disinfectants. It can also be noted that the oxidation potential of this compound is much higher than that of chlorine, therefore, when working with it, a smaller amount of other chemical reagents is required.

Prolonged disinfection is a great advantage. All microbes resistant to chlorine, such as legionella, ClO 2 destroys immediately completely. To combat such microbes, it is necessary to apply special measures, since they quickly adapt to different conditions, which in turn can be fatal to many other organisms, despite the fact that most of them are maximally resistant to disinfectants.

1.3.1.3 Water ozonation

With this method, ozone decomposes in water with the release of atomic oxygen. This oxygen is able to destroy the enzyme systems of microbial cells and oxidize most of the compounds that give water bad smell. The amount of ozone is directly proportional to the degree of water pollution. When exposed to ozone for 8-15 minutes, its amount is 1-6 mg/l, and the amount of residual ozone should not exceed 0.3-0.5 mg/l. If these standards are not observed, a high concentration of ozone will expose the metal of the pipes to destruction, and give the water a specific odor. From a hygiene point of view, this method of water disinfection is one of the best ways.

Ozonation has found application in centralized water supply, as it is energy-intensive, complex equipment is used and highly qualified service is required.

The method of water disinfection with ozone is technically complex and expensive. The technological process consists of:

stages of air purification;

air cooling and drying;

ozone synthesis;

ozone-air mixture with treated water;

removal and destruction of the residual ozone-air mixture;

the release of this mixture into the atmosphere.

Ozone is a very toxic substance. MPD in the air of industrial premises is 0.1 g/m 3 . In addition, the ozone-air mixture is explosive.

.3.1.4 Water disinfection with heavy metals

The advantage of such metals (copper, silver, etc.) is the ability to have a disinfecting effect in small concentrations, the so-called oligodynamic properties. Metals enter the water by electrochemical dissolution or directly by the salt solutions themselves.

Examples of cation exchangers and active carbons saturated with silver are C-100 Ag and C-150 Ag from Purolite. They do not allow the growth of bacteria when the water stops. The cation exchangers of the JSC NIIPM-KU-23SM and KU-23SP company contain more silver than the previous ones and are used in installations of small productivity.

.3.1.5 Decontamination with bromine and iodine

This method was widely used at the beginning of the 20th century. Bromine and iodine have greater disinfecting properties than chlorine. However, they require more sophisticated technology. When used in water disinfection, iodine is used in special ion exchangers that are saturated with iodine. To provide the necessary dose of iodine in water, water is passed through the ion exchangers, thus iodine is gradually washed out. This method of water disinfection can only be used for small installations. The downside is the impossibility of constant monitoring of the concentration of iodine, which is constantly changing.

.3.2 Physical disinfection

With this method, it is necessary to reduce the required amount of energy to a unit volume of water, which is the product of the intensity of exposure to the contact time.

Bacteria of the Escherichia coli group (ECG) and bacteria in 1 ml of water determine the contamination of water with microorganisms. The main indicator of this group is E. coli (shows bacterial contamination of water). BGKP has a high coefficient of resistance to water disinfection. It is found in water that is contaminated with feces. According to SanPiN 2.1.4.1074-01: the amount of bacteria present is no more than 50 if there are no coliform bacteria in 100 ml. An indicator of water contamination is coli-index (the presence of E. coli in 1 liter of water).

The effect of ultraviolet radiation and chlorine on viruses (virucidal effect) according to the coli index has a different meaning with the same effect. With UV radiation, the effect is stronger than with chlorine. To achieve the maximum virucidal effect, the dose of ozone is 0.5-0.8 g/l for 12 minutes, and with UV radiation - 16-40 mJ/cm 3 at the same time.

.3.2.1 UV disinfection

This is the most common water disinfection method. The action is based on the effect of UV radiation on cellular metabolism and on the enzyme systems of the microorganism cell. UV disinfection does not change the organoleptic properties of water, but at the same time it destroys spore and vegetative forms of bacteria; does not form toxic products; very efficient method. The disadvantage is the lack of aftereffect.

In terms of capital values, UV disinfection occupies an average value between chlorination (more) and ozonation (less). Along with chlorination, UFO uses low operating costs. Low energy consumption, and lamp replacement - no more than 10% of the installation price, and UV installations for individual water supply are the most attractive.

Contamination of quartz lamp covers with organic and mineral deposits reduces the efficiency of UV installations. The automatic cleaning system is used in large installations by circulating water with the addition of food acids through the installation. In other installations, cleaning occurs mechanically.

.3.2.2 Ultrasonic disinfection of water

The method is based on cavitation, i.e. the ability to form frequencies that create a large pressure difference. This leads to the death of the cell of the microorganism through the rupture of the cell membrane. The degree of bactericidal activity depends on the intensity of sound vibrations.

.3.2.3 Boiling

The most common and reliable disinfection method. With this method, not only bacteria, viruses and other microorganisms are destroyed, but also gases dissolved in water, and water hardness is also reduced. Organoleptic parameters practically do not change.

Often used for water disinfection complex method. For example, the combination of chlorination with UVR allows for a high degree of purification. The use of ozonation with gentle chlorination ensures the absence of secondary biological contamination of water and reduces the toxicity of organochlorine compounds.

.3.2.4 Decontamination by filtration

It is possible to completely purify water from microorganisms using filters if the pore size of the filter is smaller than the size of microorganisms.

2. Existing provisions

The sources of household and drinking water supply for the city of Nizhny Tagil are two reservoirs: Verkhne-Vyyskoye, located 6 km from the city of Nizhny Tagil and Chernoistochinskoye, located within the boundaries of the village of Chernoistochinsk (20 km from the city).

Table 5 - Initial water quality characteristics of reservoirs (2012)

	Component	Quantity, mg / dm 3
	Manganese
	Aluminum
	Rigidity
	Turbidity
	Perm. oxidizability
	Oil products
	Solution. oxygen
	Chroma

From the Chernoistochinsky hydroelectric complex, water is supplied to the Galyano-Gorbunovsky massif and to the Dzerzhinsky district after passing through treatment facilities, including microfilters, a mixer, a block of filters and sedimentation tanks, a reagent facility, and a chlorination plant. Water is supplied from hydroelectric facilities through distribution networks through pumping stations of the second lift with reservoirs and booster pumping stations.

The design capacity of the Chernoistochinsky hydroelectric complex is 140 thousand m 3 /day. Actual productivity - (average for 2006) - 106 thousand m 3 /day.

The pumping station of the 1st lift is located on the banks of the Chernoistochinsky reservoir and is designed to supply water from the Chernoistochinsky reservoir through the water treatment facilities to the pumping station of the 2nd lift.

Water enters the pumping station of the 1st lift through a ryazhevy head through water conduits with a diameter of 1200 mm. At the pumping station, primary mechanical purification of water from large impurities, phytoplankton takes place - the water passes through a rotating mesh of the TM-2000 type.

4 pumps are installed in the engine room of the pumping station.

After the pumping station of the 1st lift, water flows through two conduits with a diameter of 1000 mm to microfilters. Microfilters are designed to remove plankton from the water.

After the microfilters, the water flows by gravity into the vortex-type mixer. In the mixer, water is mixed with chlorine (primary chlorination) and with a coagulant (aluminum oxychloride).

After the mixer, water enters the common collector and is distributed to five settling tanks. In settling tanks, large suspensions are formed and settled with the help of a coagulant and they settle to the bottom.

After the settling tanks, water enters 5 fast filters. Double layer filters. The filters are washed daily with water from the wash tank, which is filled with finished drinking water after the pumping station of the second lift.

After the filters, the water is subjected to secondary chlorination. Wash water is discharged into the sludge reservoir, which is located behind the sanitary zone of the 1st belt.

Table 6 - Information on the quality of drinking water for July 2015 of the Chernoistochinsky distribution network

	Index	Units	Research result
	Chroma
	Turbidity
	General hardness
	Residual total chlorine
	Common coliform bacteria	CFU in 100 ml
	thermotolerant coliform bacteria	CFU in 100 ml

3. Setting the goal and objectives of the project

An analysis of the literature and the current state of drinking water treatment in the city of Nizhny Tagil showed that there are excesses in such indicators as turbidity, permanganate oxidation, dissolved oxygen, color, iron, manganese, and aluminum content.

Based on the measurements, the following goals and objectives of the project were formulated.

The aim of the project is to analyze the operation of the existing Chernoistochinsk wastewater treatment plant and propose options for its reconstruction.

Within the framework of this goal, the following tasks were solved.

Make an enlarged calculation of existing water treatment facilities.

2. Propose measures to improve the operation of water treatment facilities and develop a scheme for the reconstruction of water treatment.

Make an enlarged calculation of the proposed water treatment facilities.

4. Proposed measures to improve the efficiency of wastewater treatment plants in Nizhny Tagil

1) Replacing the PAA flocculant with Praestol 650.

Praestol 650 is a high molecular weight water soluble polymer. It is actively used for accelerating water treatment processes, compacting sediments and their further dehydration. Chemical reagents used as electrolytes reduce the electrical potential of water molecules, as a result of which the particles begin to combine with each other. Further, the flocculant acts as a polymer, which combines the particles into flakes - "flocculi". Thanks to the action of Praestol 650, micro-flakes are combined into macro-flakes, the settling speed of which is several hundred times higher than that of ordinary particles. Thus, the complex effect of the Praestol 650 flocculant contributes to the intensification of the settling of solid particles. This chemical reagent is actively used in all water purification processes.

) Installation of a chamber beam distributor

Designed for efficient mixing of treated water with solutions of reagents (in our case, sodium hypochlorite), with the exception of milk of lime. The effectiveness of the chamber-beam distributor is ensured by the inflow of a part of the source water through the circulation pipe into the chamber, dilution of the reagent solution entering the chamber through the reagent pipeline (pre-mixing) with this water, increasing the initial flow rate of the liquid reagent, which contributes to its dispersal in the flow, uniform distribution of the diluted solution over the flow cross section. The flow of raw water into the chamber through the circulation pipe occurs under the action of velocity pressure, which has the highest value in the core of the flow.

) Equipment of flocculation chambers with thin-layer modules (increase in cleaning efficiency by 25%). To intensify the operation of structures in which flocculation processes are carried out in a layer of suspended sediment, thin-layer flocculation chambers can be used. Compared to conventional bulk flocculation, the suspended layer formed in the closed space of thin-layer elements is characterized by a higher solids concentration and resistance to changes in the quality of the source water and the load on the structures.

4) Refuse primary chlorination and replace it with ozone sorption (ozone and activated carbon). Ozonation and sorption purification of water should be used in cases where the water source has a constant level of pollution with anthropogenic substances or a high content of organic substances of natural origin, characterized by indicators: color, permanganate oxidizability, etc. Ozonation of water and subsequent sorption purification on filters with active carbon in combination with The existing traditional water treatment technology provides deep water purification from organic contaminants and makes it possible to obtain high quality drinking water that is safe for public health. Taking into account the ambiguous nature of the action of ozone and the peculiarities of the use of powdered and granular activated carbons, in each case it is necessary to conduct special technological studies (or surveys) that will show the feasibility and effectiveness of using these technologies. In addition, in the course of such studies, the calculation and design parameters of the methods will be determined (optimal doses of ozone in characteristic periods of the year, ozone utilization factor, time of contact of the ozone-air mixture with treated water, type of sorbent, filtration rate, time to reactivation of the coal load and reactivation mode with determination of its instrumentation), as well as other technological and technical and economic issues of the use of ozone and activated carbons at water treatment plants.

) Water-air washing of the filter. Water-air washing has a stronger effect than water washing, and this makes it possible to obtain a high effect of cleaning the load at low flow rates of washing water, including those at which the load is not weighed in the upward flow. This feature of water-air washing allows: to reduce the intensity of supply and the total consumption of washing water by about 2 times; accordingly reduce the capacity of wash pumps and the volume of facilities for the supply of wash water, reduce the size of pipelines for its supply and discharge; reduce the volume of facilities for the treatment of waste wash water and the sediments contained in them.

) Replacing chlorination with the combined use of sodium hypochlorite and ultraviolet light. At the final stage of water disinfection, UV radiation must be used in combination with other chlorine reagents to ensure a prolonged bactericidal effect in distributing water supply networks. Disinfection of water with ultraviolet rays and sodium hypochlorite at waterworks is very effective and promising in connection with the creation of last years new economical UV disinfection units with improved quality of radiation sources and reactor designs.

Figure 1 shows the proposed scheme of the wastewater treatment plant in Nizhny Tagil.

Rice. 1 Proposed scheme for a wastewater treatment plant in Nizhny Tagil

5. Settlement part

.1 design part of existing treatment facilities

.1.1 Reagent facilities

1) Calculation of the dose of reagents

;

where D u - the amount of alkali added to alkalinize water, mg/l;

e - equivalent weight of the coagulant (anhydrous) in mg-eq / l, equal to Al 2 (SO 4) 3 57, FeCl 3 54, Fe 2 (SO 4) 3 67;

D to - the maximum dose of anhydrous aluminum sulfate in mg / l;

U - the minimum alkalinity of water in mg-eq / l, (for natural waters it is usually equal to carbonate hardness);

K - the amount of alkali in mg / l, necessary for alkalinization of water by 1 meq / l and equal to 28 mg / l for lime, 30-40 mg / l for caustic soda, 53 mg / l for soda;

C - the color of the treated water in degrees of the platinum-cobalt scale.

D to = ;

= ;

Since ˂ 0, therefore, additional alkalization of water is not required.

Determine the required doses of PAA and POHA

Estimated dose of PAA D PAA \u003d 0.5 mg / l (Table 17);

) Calculation of daily consumption of reagents

1) Calculation of the daily consumption of POHA

We prepare a solution of 25% concentration

2) Calculation of the daily consumption of PAA

We prepare a solution of 8% concentration

We prepare a solution of 1% concentration

) Reagent warehouse

Warehouse area for coagulant

.1.2 Calculation of mixers and flocculation chambers

.1.2.1 Calculation of the vortex mixer

The vertical mixer is used at water treatment plants of medium and high productivity, provided that one mixer will have a water flow rate of not more than 1200-1500 m 3 / h. Thus, 5 mixers must be installed at the station in question.

Hourly water consumption, taking into account the own needs of the treatment plant

Hourly water consumption for 1 mixer

Secondary water consumption per faucet

Horizontal area at the top of the mixer

where - the speed of the upward movement of water, equal to 90-100 m / h.

If we take the upper part of the mixer in a square plan, then its side will have the size

Piping supplying treated water to the bottom of the mixer at an input speed must have an internal diameter of 350 mm. Then at the expense of water input speed

Since the outer diameter of the supply pipeline is D = 377 mm (GOST 10704 - 63), then the size in terms of the lower part of the mixer at the junction of this pipeline should be 0.3770.377 m, and the area of ​​\u200b\u200bthe lower part of the truncated pyramid will be .

We accept the value of the central angle α=40º. Then the height of the lower (pyramidal) part of the mixer

The volume of the pyramidal part of the mixer

Full mixer volume

where t is the duration of mixing the reagent with a mass of water, equal to 1.5 minutes (less than 2 minutes).

Mixer top volume

Faucet top height

Total mixer height

Water is collected in the upper part of the mixer by a peripheral tray through flooded holes. The speed of movement of water in the tray

The water flowing through the trays towards the side pocket is divided into two parallel streams. Therefore, the estimated flow rate of each stream will be:

The area of ​​the living section of the collection tray

With the width of the tray, the estimated height of the water layer in the tray

Tray bottom slope accepted.

The area of ​​all flooded holes in the walls of the collection tray

where is the speed of water movement through the opening of the tray, equal to 1 m / s.

The holes are taken with a diameter = 80 mm, i.e. area = 0.00503 .

Total required number of holes

These holes are placed along the side surface of the tray at a depth of =110 mm from the top edge of the tray to the axis of the hole.

Tray inner diameter

Hole axis pitch

Distance between holes

.1.2.2 Swirl flocculation chamber

Estimated amount of water Q day = 140 thousand m 3 / day.

Flocculation chamber volume

The number of flocculation chambers N=5.

Single camera performance

where is the residence time of water in the chamber, equal to 8 min.

At the speed of the upward movement of water in the upper part of the chamber the cross-sectional area of ​​the upper part of the chamber and its diameter are equal

At entry speed the diameter of the lower part of the chamber and its cross-sectional area are equal to:

We accept the diameter of the bottom of the chamber . The rate of water entry into the chamber will be .

The height of the conical part of the flocculation chamber at the taper angle

The volume of the conical part of the chamber

The volume of the cylindrical extension above the cone

5.1.3 Calculation of the horizontal sump

The initial and final (at the outlet of the sump) content of suspended matter is 340 and 9.5 mg/l, respectively.

We accept u 0 = 0.5 mm / s (according to Table 27) and then, given the ratio L / H = 15, according to Table. 26 we find: α \u003d 1.5 and υ cf \u003d Ku 0 \u003d 100.5 \u003d 5 mm / s.

The area of ​​all sedimentation tanks in the plan

F total \u003d \u003d 4860 m 2.

The depth of the precipitation zone in accordance with the height scheme of the station is assumed to be H = 2.6 m (recommended H = 2.53.5 m). Estimated number of simultaneously operating settling tanks N = 5.

Then the width of the sump

B==24m.

Inside each sump, two longitudinal vertical partitions are installed, forming three parallel corridors 8 m wide each.

Sump length

L = = = 40.5 m.

With this ratio L:H = 40.5:2.6 15, i.e. corresponds to the data in Table 26.

At the beginning and end of the sump, transverse water-distributing perforated partitions are installed.

The working area of ​​such a distribution partition in each corridor of the sedimentation tank with a width of b c = 8 m.

f slave \u003d b k (H-0.3) \u003d 8 (2.6-0.3) \u003d 18.4 m 2.

Estimated water flow for each of the 40 corridors

q k \u003d Q hour: 40 \u003d 5833: 40 \u003d 145 m 3 / h, or 0.04 m 3 / sec.

Required area of ​​openings in distribution partitions:

a) at the beginning of the sump

Ʃ =: = 0.04: 0.3 = 0.13 m 2

(where - the speed of water movement in the openings of the partition, equal to 0.3 m / s)

b) at the end of the sump

Ʃ =: = 0.04: 0.5 = 0.08 m 2

(where is the water velocity in the holes of the end partition, equal to 0.5 m / s)

We accept holes in the front partition d 1 \u003d 0.05 m with an area \u003d 0.00196 m 2 each, then the number of holes in the front partition \u003d 0.13: 0.00196 66. In the end partition, holes are taken with a diameter of d 2 \u003d 0.04 m and area \u003d 0.00126 m 2 each, then the number of holes \u003d 0.08: 0.00126 63.

We accept 63 holes in each partition, placing them in seven rows horizontally and nine rows vertically. The distances between the axes of the holes: vertically 2.3:7 0.3 m and horizontally 3:9 0.33 m.

Removal of sludge without terminating the operation of the horizontal settling tank

Let us assume that the sludge is discharged once within three days with a duration of 10 minutes without shutting down the sump from operation.

The amount of sediment removed from each sump per cleaning, according to the formula 40

where - the average concentration of suspended particles in the water entering the sump for the period between cleanings, in g / m 3;

The amount of suspension in the water leaving the sump, in mg / l (8-12 mg / l is allowed);

The number of settling tanks.

Percentage of water consumed by periodic sludge discharge formula 41

Sludge dilution factor taken equal to 1.3 for periodic sludge removal with sump emptying and 1.5 for continuous sludge removal.

.1.4 Calculation of quick non-pressure filters with double-layer loading

1) Filter sizing

The total area of ​​filters with a two-layer load at (according to formula 77)

where - the duration of the station during the day in hours;

Estimated filtration rate under normal operation, equal to 6 m/h;

The number of washings of each filter per day, equal to 2;

Washing intensity equal to 12.5 l/sec 2 ;

The duration of the wash, equal to 0.1 h;

Filter downtime due to flushing equal to 0.33 hours.

Number of filters N=5.

Single filter area

The size of the filter in plan is 14.6214.62 m.

Water filtration rate in forced mode

where is the number of filters being repaired ().

2) Selection of the composition of the filter load

In accordance with the data in Table. 32 and 33 fast two-layer filters are loaded (counting from top to bottom):

a) anthracite with a grain size of 0.8-1.8 mm and a layer thickness of 0.4 m;

b) quartz sand with a grain size of 0.5-1.2 mm and a layer thickness of 0.6 m;

c) gravel with a grain size of 2-32 mm and a layer thickness of 0.6 m.

The total water height above the filter loading surface is assumed

) Calculation of filter distribution system

Flow rate of flushing water entering the distribution system during intensive flushing

Distribution system header diameter adopted based on the speed of the wash water which corresponds to the recommended speed of 1 - 1.2 m/sec.

With a filter size in plan view of 14.6214.62 m, the length of the hole

where = 630 mm - outside diameter collector (according to GOST 10704-63).

The number of branches on each filter with the step of the branch axis will be

Branches accommodates 56 pcs. on each side of the manifold.

We accept the diameter of steel pipes (GOST 3262-62), then the inlet rate of wash water in the branch at flow rate will be .

In the lower part of the branches at an angle of 60º to the vertical, holes with a diameter of 10-14 mm are provided. We accept holes δ \u003d 14 mm each with an area The ratio of the area of ​​all holes per branch of the distribution system to the area of ​​the filter is assumed to be 0.25-0.3%. Then

Total number of openings in the distribution system of each filter

Each filter has 112 taps. Then the number of holes on each branch is 410:1124 pcs. Hole axis pitch

4) Calculation of devices for collecting and draining water when washing the filter

At the consumption of wash water per filter and the number of gutters, the water consumption per one gutter will be

0.926 m 3 / sec.

Distance between axes of gutters

The width of the gutter with a triangular base is determined by formula 86. At the height of the rectangular part of the gutter, the value .

The K factor for a gutter with a triangular base is 2.1. Consequently,

The height of the gutter is 0.5 m, and taking into account the wall thickness, its total height will be 0.5 + 0.08 = 0.58 m; speed of water in the gutter . According to Table. 40 gutter dimensions will be: .

The height of the edge of the chute above the loading surface according to the formula 63

where is the height of the filter layer in m,

Relative expansion of the filter load in% (Table 37).

Water consumption for washing the filter according to the formula 88

The water consumption for washing the filter will be

In general, it took

Sediment in the filter 12 mg / l = 12 g / m 3

Sediment weight in source water

The mass of sediment in the water after the filter

Particulate matter caught

Suspended solids concentration

.1.5 Calculation of the chlorination plant for dosing liquid chlorine

Chlorine is introduced into the water in two stages.

Estimated hourly consumption of chlorine for water chlorination:

Preliminary at = 5 mg/l

: 24 = : 24 = 29.2 kg/h;

secondary at = 2 mg/l

: 24 = : 24 = 11.7 kg/h.

The total consumption of chlorine is 40.9 kg/h, or 981.6 kg/day.

The optimal doses of chlorine are prescribed according to the data of trial operation by trial chlorination of the treated water.

The performance of the chlorination room is 981.6 kg/day ˃ 250 kg/day, so the room is divided by a blank wall into two parts (the chlorination room itself and the control room) with independent emergency exits to the outside from each. water treatment disinfection coagulant chlorine

In the control room, in addition to chlorinators, three vacuum chlorinators with a capacity of up to 10 g/h with a gas meter are installed. Two chlorinators are working, and one serves as a backup.

In addition to chlorinators, three intermediate chlorine cylinders are installed in the control room.

The performance of the plant under consideration for chlorine is 40.9 kg/h. This makes it necessary to have a large number of consumable and chlorine cylinders, namely:

n ball \u003d Q chl: S ball \u003d 40.9: 0.5 \u003d 81 pcs.,

where S ball \u003d 0.50.7 kg / h - chlorine removal from one cylinder without artificial heating at an air temperature in the room of 18 ºС.

To reduce the number of supply cylinders, steel evaporating barrels with a diameter D = 0.746 m and a length l = 1.6 m are installed in the chlorination room. The removal of chlorine from 1 m 2 of the side surface of the barrels is Schl = 3 kg / h. The side surface of the barrel with the dimensions taken above will be 3.65 m 2.

Thus, eating chlorine from one barrel will

q b \u003d F b S chl \u003d 3.65 ∙ 3 \u003d 10.95 kg / h.

To ensure the supply of chlorine in the amount of 40.9 kg / h, you need to have 40.9: 10.95 3 evaporator barrels. To replenish the consumption of chlorine from the barrel, it is poured from standard cylinders with a capacity of 55 liters, creating a vacuum in the barrels by sucking chlorine gas with an ejector. This event allows you to increase the removal of chlorine up to 5 kg/h from one cylinder and, consequently, reduce the number of simultaneously operating supply cylinders to 40.9:5 8 pcs.

In just a day, you will need cylinders with liquid chlorine 981.6:55 17 pcs.

The number of cylinders in this warehouse should be 3∙17 = 51 pcs. The warehouse should not have direct communication with the chlorination plant.

monthly chlorine requirement

n ball = 535 standard type cylinders.

.1.6 Calculation of clean water tanks

The volume of clean water tanks is determined by the formula:

where - control capacity, m³;

Inviolable fire-fighting water supply, m³;

The supply of water for washing quick filters and other auxiliary needs of the treatment plant, m³.

The regulating capacity of the tanks is determined (in % of the daily water consumption) by combining the work schedules of the pumping station of the 1st lift and the pumping station of the 2nd lift. In this work, this is the area of ​​the graph between the lines of water entering the tanks from the treatment facilities in the amount of about 4.17% of the daily consumption and pumping it out of the tanks pumping station 2nd rise (5% of the daily) for 16 hours (from 5 to 21 hours). Converting this area from percent to m 3, we get:

here 4.17% is the amount of water entering the reservoirs from the wastewater treatment plant;

% - the amount of water pumped out of the reservoir;

The time during which pumping occurs, h.

The emergency fire-fighting water supply is determined by the formula:

where is the hourly water consumption for extinguishing fires, equal to;

The hourly flow rate of water entering the tanks from the side of the treatment plant is equal to

Let's take N=10 tanks - the total area of ​​filters equal to 120 m 2 ;

According to paragraph 9.21, and also taking into account the regulating, fire, contact and emergency water supplies, four rectangular tanks of the PE-100M-60 brand (No. standard project 901-4-62.83) with a volume of 6000 m 3 .

To ensure contact of chlorine with water in the tank, it is necessary to ensure that water stays in the tank for at least 30 minutes. The contact volume of the tanks will be:

where is the contact time of chlorine with water, equal to 30 minutes;

This volume is much less than the volume of the tank, therefore, the necessary contact of water and chlorine is ensured.

.2 Estimated part of the proposed treatment facilities

.2.1 Reagent facility

1) Calculation of doses of reagents

In connection with the use of water-air washing, the consumption of washing water will decrease by 2.5 times

.2.4 Calculation of the ozonating plant

1) Layout and calculation of the ozonizer unit

Consumption of ozonized water Q day = 140000 m 3 / day or Q hour = 5833 m 3 / h. Ozone doses: maximum q max =5 g/m 3 and average annual q cf =2.6 g/m 3 .

Maximum calculated ozone consumption:

Or 29.2 kg/h

Duration of contact of water with ozone t=6 minutes.

Adopted tubular ozonizer with a capacity of G oz =1500 g/h. In order to produce ozone in the amount of 29.2 kg/h, the ozonizing plant must be equipped with 29200/1500≈19 working ozonizers. In addition, one backup ozonator of the same capacity (1.5 kg/h) is required.

The active power of the ozone generator discharge U is a function of voltage and current frequency and can be determined by the formula:

The cross-sectional area of ​​the annular discharge gap is found by the formula:

The speed of passage of dry air through the annular discharge gap in order to save energy consumption is recommended within =0.15÷0.2 m/sec.

Then the flow rate of dry air through one tube of the ozonizer:

Since the specified performance of one ozonizer G oz =1.5 kg/h, then with the coefficient of ozone weight concentration K oz =20 g/m 3 the amount of dry air required for electrosynthesis is:

Therefore, the number of glass dielectric tubes in one ozonator should be

n tr \u003d Q in / q in \u003d 75 / 0.5 \u003d 150 pcs.

Glass tubes 1.6 m long are placed concentrically in 75 steel tubes passing through the entire cylindrical body of the ozonizer from both ends. Then the length of the body of the ozonizer will be l= 3.6 m.

Ozone capacity of each tube:

Energy output of ozone:

The total cross-sectional area of ​​75 tubes d 1 =0.092 m is ∑f tr =75×0.785×0.092 2 ≈0.5 m 2 .

The cross-sectional area of ​​the cylindrical body of the ozonizer should be 35% larger, i.e.

F k \u003d 1.35 ∑ f tr \u003d 1.35 × 0.5 \u003d 0.675 m 2.

Therefore, the inner diameter of the ozonator body will be:

It must be borne in mind that 85-90% of the electricity consumed for the production of ozone is spent on heat generation. In this regard, it is necessary to ensure the cooling of the electrodes of the ozonizer. Water consumption for cooling is 35 l/h per tube, or in total Q cool =150×35=5250 l/h or 1.46 l/s.

The average speed of the cooling water will be:

Or 8.3 mm/s

Cooling water temperature t=10 °C.

For electrosynthesis of ozone, 75 m 3 /h of dry air must be supplied to one ozonizer of the accepted capacity. In addition, it is necessary to take into account the air consumption for adsorber regeneration, which is 360 m 3 /h for a commercially available AG-50 unit.

Total cooled air flow:

V o.v \u003d 2 × 75 + 360 \u003d 510 m 3 / h or 8.5 m 3 / min.

For air supply, we use VK-12 water ring blowers with a capacity of 10 m 3 /min. Then it is necessary to install one working blower and one standby blower with A-82-6 electric motors with a power of 40 kW each.

A viscin filter with a capacity of up to 50 m 3 /min is installed on the suction pipeline of each blower, which satisfies the design conditions.

2) Calculation of the contact chamber for mixing the ozone-air mixture with water.

Required cross-sectional area of ​​the contact chamber in plan:

where is the consumption of ozonized water in m 3 / h;

T is the duration of contact of ozone with water; taken within 5-10 minutes;

n is the number of contact chambers;

H is the depth of the water layer in the contact chamber, m; 4.5-5 m is usually taken.

Camera size accepted

For uniform spraying of ozonized air, perforated pipes are placed at the bottom of the contact chamber. We accept ceramic porous pipes.

The frame is a stainless steel pipe (outer diameter 57 mm ) with holes with a diameter of 4-6 mm. A filter pipe is put on it - a ceramic block with a length l=500 mm, inner diameter 64 mm and outer diameter 92 mm.

The active surface of the block, i.e., the area of ​​all 100 micron pores on the ceramic tube, occupies 25% of the inner surface of the tube, then

f p \u003d 0.25D in l\u003d 0.25 × 3.14 × 0.064 × 0.5 \u003d 0.0251 m 2.

The amount of ozonized air is q oz.v ≈150 m 3 /h or 0.042 m 3 /sec. The cross-sectional area of ​​the main (frame) distribution pipe with an inner diameter of d=49 mm is equal to: f tr =0.00188 m 2 =18.8 cm 2 .

We accept in each contact chamber four main distribution pipes laid at mutual distances (between the axes) of 0.9 m. Each pipe consists of eight ceramic blocks. With this arrangement of pipes, we accept the dimensions of the contact chamber in terms of 3.7 × 5.4 m.

The consumption of ozonized air per free section of each of the four pipes in two chambers will be:

q tr \u003d≈0.01 m 3 / s,

and the speed of air movement in the pipeline is equal to:

≈5.56 m/sec.

active carbon layer height - 1-2.5 m;

contact time of treated water with coal - 6-15 minutes;

washing intensity - 10 l / (s × m 2) (for coals AGM and AGOV) and 14-15 l / (s × m 2) (for coals of grades AG-3 and DAU);

flushing of the coal load should be carried out at least once every 2-3 days. Washing time is 7-10 minutes.

During the operation of carbon filters, the annual loss of coal is up to 10%. Therefore, at the station it is necessary to have a supply of coal for additional loading of filters. The distribution system of coal filters is gravel-free (from slotted polyethylene pipes, cap or polymer concrete drainage).

) Filter sizing

The total area of ​​the filters is determined by the formula:

Number of filters:

PCS. + 1 spare.

Let's determine the area of ​​one filter:

The coefficient of resistance of irradiated bacteria, taken equal to 2500 μW

The proposed option for the reconstruction of the water treatment plant:

equipment of flocculation chambers with thin-layer modules;

replacement of primary chlorination with ozone sorption;

application of water-air washing of filters 4

replacing chlorination with sharing sodium hypochlorite and ultraviolet;

replacement of PAA flocculant with Praestol 650.

The reconstruction will reduce the concentration of pollutants to the following values:

· permanganate oxidizability - 0.5 mg/l;

Dissolved oxygen - 8 mg/l;

chromaticity - 7-8 degrees;

manganese - 0.1 mg/l;

aluminum - 0.5 mg/l.

Bibliographic list

SanPiN 2.1.4.1074-01. Editions. Drinking water and water supply of populated areas. - M.: Publishing house of standards, 2012. - 84 p.

Guidelines for drinking water quality control, 1992.

U.S. Environmental Protection Agency Regulations

Elizarova, T.V. Hygiene of drinking water: account. allowance / T.V. Elizarova, A.A. Mikhailov. - Chita: ChGMA, 2014. - 63 p.

Kamaliev, A.R. Comprehensive assessment of the quality of aluminum and iron-containing reagents for water treatment / A.R. Kamalieva, I.D. Sorokina, A.F. Dresvyannikov // Water: chemistry and ecology. - 2015. - No. 2. - S. 78-84.

Soshnikov, E.V. Disinfection of natural waters: account. allowance / E.V. Soshnikov, G.P. Chaikovsky. - Khabarovsk: Publishing House of the Far East State University of Transportation, 2004. - 111 p.

Draginsky, V.L. Proposals for improving the efficiency of water purification in the preparation of water treatment plants to meet the requirements of SanPiN "Drinking water. Hygienic requirements for water quality in centralized drinking water supply systems. Quality control" / V.L. Draginsky, V.M. Korabelnikov, L.P. Alekseev. - M.: Standart, 2008. - 20 p.

Belikov, S.E. Water treatment: a reference book / S.E. Belikov. - M: Aqua-Therm Publishing House, 2007. - 240 p.

Kozhinov, V.F. Purification of drinking and technical water: textbook / V.F. Kozhinov. - Minsk: Publishing House "Higher School A", 2007. - 300 p.

SP 31.13330.2012. Editions. Water supply. External networks and structures. - M.: Publishing house of standards, 2012. - 128 p.

Based on the results of a home test, the quality of your tap water can be improved.

Drinking water supplied to city ​​apartment, has already passed the stage of cleaning and disinfection at the water treatment plant.

Tap water may contain impurities and contaminants that are either not completely removed at the tap water treatment plant, or appear in the water already on the way to the consumer.

Many substances that pollute water contribute to the formation of cloudy suspensions, cause an unpleasant odor, a characteristic taste, and can also color water in one or another color.

However, the presence of some impurities may not affect the appearance tap water.

Simple ways to make tap water cleaner and safer .

• Before using tap water, drain it for a few minutes, as it quickly stagnates in pipes.
• Let the water sit in an open vessel to allow any residual chlorine to escape.
• Then filter the water through any filter. Even the simplest accumulative type, better than nothing. Filtration will remove the suspension and part of the microorganisms from the water.

You have found cloudiness in the water.

muddy water- this is the result of the presence of suspended and colloidal impurities in the water, or an increased content of air in the water.

Suspended and colloidal particles- these are very small particles: compounds of aluminum and iron, silicon, waste products and decay of plants and animals.

To purify water from these pollutants, it is recommended to use a combination of mechanical filters (with inert loading) and carbon filters with loading from activated carbon.

You have discovered a color in the water.

Color may be due to dissolved and suspended particles of mineral and organic origin.

yellow tint of water- the presence of humic substances (humic and fulvic acids), or an increased content of iron.

Gray shade of water- high content of manganese, iron

reddish brown precipitate- the presence of oxidized iron in the water.

To purify water from these contaminants, it is recommended to use a preliminary treatment on a mechanical filter and then a filter with a carbon load or a reverse osmosis system.

Did you find the smell in the water? .

Smell fishy or musty- presence of organochlorine compounds in water.

Smell of hydrogen sulfide (rotten eggs smell)- ingress of sewage into the water supply system or the vital activity of bacteria that form hydrogen sulfide from sulfates.

Chlorine smell- high content of residual chlorine in the water.

The smell of petroleum products- ingress of oil products into the water supply system.

Chemical smell, phenol smell- water pollution by industrial effluents, in particular, effluents from organic chemistry enterprises.

To purify water from these contaminants, it is recommended to use a carbon-loaded filter or a reverse osmosis system.

Did you find a taste in the water .

Salty taste- high content of sodium and magnesium salts

To purify water from these pollutants, it is recommended to use a reverse osmosis system.

Taste metallic- high iron content.

Taste due to organic impurities.

Alkaline taste- high alkalinity of water, increased hardness, high content of dissolved substances.

You found scale in the kettle.

Scale indicates the presence of excess calcium and magnesium salts in the water.

Nitrates in water

The source of nitrates in water is fertilizers and wastewater that enters surface and underground water bodies. The high content of nitrates in water is dangerous for humans and especially for children. It is known that in the body part of the nitrates is converted into a more toxic substance - nitrites.

It should be noted that a universal filter that cleans everything: from chlorine, from iron, from organics, from metals, from bacteria, and ... does not exist.

For each type of pollution, a certain type of filter is used. Therefore, the optimal treatment plant should consist of a properly selected set of nodes, each of which removes a certain type of pollution.

In any case, systems of treatment plants, consisting of several successively operating filters with different loads, provide better water purification than a filter with the same type of load.

To purify drinking water, as a rule, a set of filters is used with various loads or membranes corresponding to the type of contaminants that need to be removed from the water. Often the treatment system includes water disinfection.

Below are the main components of drinking water treatment plants to help you choose the right design.

Mechanical filters remove suspended solids from the water.

Porous materials (usually ceramic) are used as loading.

Carbon filters made on the basis of activated carbon, which is a good adsorbent.

The carbon filter purifies water from residual chlorine, dissolved gases, organic compounds, including toxins, odor and improves the taste of water.

Filters for iron removal remove iron and manganese. For their manufacture, special polymers are used that accelerate the oxidation of the metal. The precipitate obtained as a result of the reaction is retained by the filter system.

Filters with ion-exchange loading. Depending on the type of ion exchange load, these filters remove various ions from the water, including those effective for reducing hardness and removing nitrates from water.

Reverse osmosis water treatment plants

The reverse osmosis system includes a special membrane through which drinking water is passed. The membranes retain 95 - 99.5% of all impurities.

It must be remembered that most of the useful substances necessary for the life of the body are also removed from the water. Such water disrupts the functioning of the body. First of all, this refers to the strength of bones, which depends on the amount of calcium in the blood.

The lack of trace elements in water affects the functioning of the liver, kidneys, nervous and immune systems. Therefore, salts and trace elements necessary for the body should be added to water purified by reverse osmosis.

Installations for water disinfection based on ultraviolet radiation.

Ultraviolet radiation inactivates pathogens. These settings are required for country houses and in the countryside. In urban apartments, such systems are used in case of ineffective disinfection of tap water at central treatment facilities.

Technical requirements and rules for the operation of a drinking water treatment plant.

• the system must provide effective water purification.
• non-toxic materials must be used for the construction of plant components (housing, pipes, loading…).
• extracted from the water, during the purification process, the impurities should not re-contaminate the purified water.
• timely washing and replacement of filter elements and bactericidal lamps is obligatory.

note that optimal choice purification systems (type of filters, loadings, method of disinfection, etc.) can be made only on the basis of the results of a laboratory chemical analysis of your drinking water.

What parameters it is desirable to check in your water:

Hydrogen index (pH), total mineralization, organic substances (permanganate oxidizability, or total organic carbon), petroleum products, nitrates, nitrites, cyanides, fluorides, hardness, heavy metals, common coliform bacteria, Giardia cysts, pesticides, organohalogen compounds.

In addition, after selecting and installing a purification system, take samples of purified water to the laboratory for chemical analysis to verify the effectiveness of purification.

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Water is an integral part of our life. Every day we drink a certain amount and often do not even think about the fact that water disinfection and its quality are an important topic. But in vain, heavy metals, chemical compounds and pathogenic bacteria can cause irreversible changes in the human body. Today, water hygiene is given serious attention. Modern methods of disinfection of drinking water are able to purify it from bacteria, fungi, viruses. They will come to the rescue even if the water smells bad, has extraneous flavors, color.

Preferred quality improvement methods are selected depending on the microorganisms contained in the water, the level of contamination, the source of the water supply and other factors. Disinfection is aimed at removing pathogenic bacteria that have a destructive effect on the human body.

Purified water is transparent, has no foreign tastes and odors, and is absolutely safe. In practice, methods of two groups are used to combat harmful microorganisms, as well as their combination:

• chemical;
• physical;
• combined.

In order to select effective methods of disinfection, it is necessary to analyze the liquid. The analyzes carried out include:

• chemical;
• bacteriological;

The use of chemical analysis allows you to determine the content of various chemical elements in water: nitrates, sulfates, chlorides, fluorides, etc. Nevertheless, the indicators analyzed by this method can be divided into 4 groups:

1. Organoleptic indicators. Chemical analysis of water allows you to determine its taste, smell and color.
2. Integral indicators - density, acidity and hardness of water.
3. Inorganic - Various metals found in water.
4. Organic indicators - the content in water of substances that can change under the influence of oxidizing agents.

Bacteriological analysis is aimed at identifying various microorganisms: bacteria, viruses, fungi. Such an analysis identifies the source of infection and helps determine methods of disinfection.

Chemical methods of drinking water disinfection

Chemical methods are based on the addition of various oxidizing agents to water that kill harmful bacteria. The most popular among such substances are chlorine, ozone, sodium hypochlorite, chlorine dioxide.

To achieve high quality, it is important to correctly calculate the dose of the reagent. A small amount of a substance may not have an effect, but on the contrary, contribute to an increase in the number of bacteria. The reagent must be introduced in excess, this will destroy both existing microorganisms and bacteria that have entered the water after disinfection.

Excess must be calculated very carefully so that it cannot harm people. The most popular chemical methods:

• chlorination;
• ozonation;
• oligodynamia;
• polymer reagents;
• iodination;
• bromination.

Chlorination

Water purification by chlorination is a traditional and one of the most popular methods of water purification. Chlorine-containing substances are actively used to purify drinking water, water in swimming pools, and disinfect premises.

Your popularity this method acquired due to ease of use, low cost, high efficiency. Most pathogenic microorganisms that cause various diseases are not resistant to chlorine, which has a bactericidal effect.

To create unfavorable conditions that prevent the reproduction and development of microorganisms, it is enough to introduce chlorine in a small excess. Excess chlorine contributes to the prolongation of the disinfection effect.

In the process of water treatment, the following methods of chlorination are possible: preliminary and final. Pre-chlorination is used as close as possible to the place of water intake; at this stage, the use of chlorine not only disinfects the water, but also helps to remove a number of chemical elements, including iron and manganese. Final chlorination - final stage during processing, during which the destruction of harmful microorganisms by means of chlorine.

A distinction is also made between normal chlorination and overchlorination. Normal chlorination is used to disinfect liquid from sources with good sanitary indicators. Overchlorination - in case of severe contamination of water, as well as if it is contaminated with phenols, which, in the case of normal chlorination, only aggravate the condition of the water. Residual chlorine is then removed by dechlorination.

Chlorination, like other methods, along with advantages, has its drawbacks. Getting into the human body in excess, chlorine leads to problems with the kidneys, liver, gastrointestinal tract. The high corrosivity of chlorine leads to rapid wear of equipment. In the process of chlorination, various by-products are formed. For example, trihalomethanes (chlorine compounds with substances of organic origin) can cause asthma symptoms.

Due to the wide use of chlorination, a number of microorganisms have developed resistance to chlorine, so a certain percentage of water contamination is still possible.

Chlorine gas, bleach, chlorine dioxide, and sodium hypochlorite are most commonly used for water disinfection.

Chlorine is the most popular reagent. It is used in liquid and gaseous form. Destroying pathogenic microflora, eliminates unpleasant taste and smell. Prevents algae growth and improves fluid quality.

For purification with chlorine, chlorinators are used, in which gaseous chlorine is absorbed with water, and then the resulting liquid is delivered to the place of application. Despite the popularity of this method, it is quite dangerous. Transportation and storage of highly toxic chlorine requires compliance with safety regulations.

Chlorine lime is a substance obtained by the action of chlorine gas on dry slaked lime. To disinfect the liquid, bleach is used, the percentage of chlorine in which is at least 32-35%. This reagent is very dangerous for humans, causing difficulties in production. Due to these and other factors, bleach is losing its popularity.

Chlorine dioxide has a bactericidal effect, practically does not pollute water. Unlike chlorine, it does not form trihalomethanes. The main reason that slows down its use is high explosiveness, which makes it difficult to manufacture, transport and store. At present, the technology of production at the place of application has been mastered. Destroys all types of microorganisms. To disadvantages can be attributed to the ability to form secondary compounds - chlorates and chlorites.

Sodium hypochlorite is used in liquid form. The percentage of active chlorine in it is twice as much as in bleach. Unlike titanium dioxide, it is relatively safe to store and use. A number of bacteria are resistant to its effects. In case of long-term storage, it loses its properties. Present on the market in the form liquid solution with different chlorine content.

It should be noted that all chlorine-containing reagents are highly corrosive, and therefore they are not recommended for purifying water entering water through metal pipelines.

Ozonation

Ozone, like chlorine, is a strong oxidizing agent. Penetrating through the membranes of microorganisms, it destroys the walls of the cell and kills it. both with disinfection of water, and with its discoloration and deodorized. Able to oxidize iron and manganese.

Possessing a high antiseptic effect, ozone destroys harmful microorganisms hundreds of times faster than other reagents. Unlike chlorine, it destroys almost all known types of microorganisms.

Upon decomposition, the reagent is converted into oxygen, which saturates the human body at the cellular level. At the same time, the rapid decay of ozone is also a disadvantage of this method, since already after 15-20 minutes. after the procedure, the water may be re-infected. There is a theory according to which, when ozone acts on water, the decomposition of phenolic groups of humic substances begins. They activate organisms that were dormant until the moment of treatment.

When saturated with ozone, water becomes corrosive. This leads to damage to water pipes, plumbing, household appliances. In the case of an erroneous amount of ozone, the formation of by-products that are highly toxic is possible.

Ozonation has other disadvantages, which include the high cost of purchase and installation, high electrical costs, as well as the high hazard class of ozone. When working with the reagent, care and safety precautions must be observed.

Water ozonation is possible using a system consisting of:

• ozone generator, in which the process of ozone extraction from oxygen takes place;
• a system that allows you to introduce ozone into water and mix it with a liquid;
• reactor - a container in which ozone interacts with water;
• destructor - a device that removes residual ozone, as well as devices that control ozone in water and air.

Oligodynamia

Oligodynamia is the disinfection of water by exposure to noble metals. The most studied use of gold, silver and copper.

The most popular metal in order to destroy harmful microorganisms is silver. Its properties were discovered in ancient times, a spoon or silver coin was placed in a container with water and the water was allowed to settle. The assertion that such a method is effective is rather controversial.

Theories of the effect of silver on microbes have not received final confirmation. There is a hypothesis according to which the cell is destroyed by electrostatic forces that arise between silver ions with a positive charge and negatively charged bacterial cells.

Silver is a heavy metal that, if accumulated in the body, can cause a number of diseases. It is possible to achieve an antiseptic effect only at high concentrations of this metal, which is detrimental to the body. A smaller amount of silver can only stop the growth of bacteria.

In addition, spore-forming bacteria are practically insensitive to silver; its effect on viruses has not been proven. Therefore, the use of silver is advisable only to extend the shelf life of initially pure water.

Copper is another heavy metal that can have a bactericidal effect. Even in ancient times, it was noticed that the water that stood in copper vessels retained its high substances much longer. In practice, this method is used in the main living conditions to purify a small amount of water.

Polymer reagents

The use of polymer reagents - modern method water disinfection. It significantly outperforms chlorination and ozonation due to its safety. The liquid purified with polymeric antiseptics has no taste and foreign odors, does not cause metal corrosion, and does not affect the human body. This method has become widespread in the purification of water in swimming pools. Water purified by a polymeric reagent has no color, foreign taste and smell.

Iodization and bromination

Iodization is a disinfection method using iodine-containing compounds. The disinfectant properties of iodine have been known to medicine since ancient times. Despite the fact that this method is widely known and several attempts have been made to use it, the use of iodine as a water disinfectant has not gained popularity. This method has a significant drawback, dissolving in water, it causes a specific smell.

Bromine is a fairly effective reagent that destroys most known bacteria. However, due to its high cost, it is not popular.

Physical methods of water disinfection

Physical methods of cleaning and disinfection work with water without the use of reagents and interference with the chemical composition. The most popular physical methods:

• UV irradiation;
• ultrasonic impact;
• heat treatment;
• electropulse method;

UV radiation

The use of UV radiation is gaining more and more popularity among the methods of water disinfection. The technique is based on the fact that rays with a wavelength of 200-295 nm can kill pathogenic microorganisms. Penetrating through the cell wall, they act on nucleic acids (RND and DNA), and also cause disturbances in the structure of membranes and cell walls of microorganisms, which leads to the death of bacteria.

To determine the dose of radiation, it is necessary to conduct a bacteriological analysis of water, this will identify the types of pathogenic microorganisms and their susceptibility to the rays. The efficiency is also affected by the power of the lamp used and the level of absorption of radiation by water.

The dose of UV radiation is equal to the product of the radiation intensity and its duration. The higher the resistance of microorganisms, the longer they need to be affected.

UV radiation does not affect the chemical composition of water, does not form side compounds, thus eliminating the possibility of harm to humans.

When using this method, an overdose is impossible, UV irradiation is characterized by a high reaction rate, it takes several seconds to disinfect the entire volume of liquid. Without changing the composition of water, radiation is capable of destroying all known microorganisms.

However, this method is not without drawbacks. Unlike chlorination, which has a prolonging effect, the effectiveness of irradiation is maintained as long as the rays affect the water.

A good result is achievable only in purified water. The level of ultraviolet absorption is affected by the impurities contained in the water. For example, iron can serve as a kind of shield for bacteria and "hide" them from exposure to rays. Therefore, it is advisable to carry out preliminary water purification.

The system for UV radiation consists of several elements: a chamber made of stainless steel, in which a lamp is placed, protected by quartz covers. Passing through the mechanism of such an installation, water is constantly exposed to ultraviolet radiation and is completely disinfected.

Ultrasonic disinfection

Ultrasonic disinfection is based on the cavitation method. Due to the fact that under the influence of ultrasound there are sharp pressure drops, microorganisms are destroyed. Ultrasound is also effective against algae

This method has a narrow range of use and is under development. The advantage is insensitivity to high turbidity and color of water, as well as the ability to act on most forms of microorganisms.

Unfortunately, this method is applicable only for small volumes of water. Like UV radiation, it has an effect only in the process of interaction with water. Ultrasonic disinfection has not gained popularity due to the need to install complex and expensive equipment.

Thermal water treatment

At home, the thermal method of water purification is the well-known boiling. The high temperature kills most microorganisms. In industrial conditions, this method is inefficient due to its bulkiness, large time costs and low intensity. In addition, heat treatment is not able to get rid of extraneous flavors and pathogenic spores.

Electropulse method

The electropulse method is based on the use of electric discharges that form a shock wave. Microorganisms die under the influence of water hammer. This method is effective for both vegetative and spore-forming bacteria. Able to achieve results even in muddy water. In addition, the bactericidal properties of treated water last up to four months.

The downside is high energy consumption and high cost.

Combined methods of water disinfection

To achieve the greatest effect, combined methods are used, as a rule, reagent methods are combined with reagentless ones.

The combination of UV irradiation with chlorination has become very popular. So, UV rays kill pathogenic microflora, and chlorine prevents re-infection. This method is used both for drinking water purification and water purification in swimming pools.

For disinfection of swimming pools, UV radiation is mainly used with sodium hypochlorite.

You can replace chlorination at the first stage with ozonation

Other methods include oxidation combined with heavy metals. Both chlorine-containing elements and ozone can act as oxidizing agents. The essence of the combination is that oxidizers cover harmful microbes, and heavy metals allow you to keep the water disinfected. There are other ways of complex disinfection of water.

Purification and disinfection of water at home

Often it is necessary to purify water in small quantities right here and now. For these purposes, use:

• soluble disinfecting tablets;
• potassium permanganate;
• silicon;
• improvised flowers, herbs.

Decontaminating tablets can help out in field conditions. As a rule, one tablet is used for 1 liter. water. This method can be attributed to the chemical group. Most often, these tablets are based on active chlorine. The duration of the tablet is 15-20 minutes. In case of severe contamination, the amount can be doubled.

If suddenly there were no tablets, it is possible to use ordinary potassium permanganate at the rate of 1-2 g per bucket of water. After the water settles, it is ready for use.

Also, natural plants have a bactericidal effect - chamomile, celandine, St. John's wort, lingonberries.

Another reagent is silicon. Place it in water and let it sit for a day.

Sources of water supply and their suitability for disinfection

Sources of water supply can be divided into two types - surface and groundwater. The first group includes water from rivers and lakes, seas and reservoirs.

When analyzing the suitability of waters for drinking located on the surface, bacteriological and chemical analysis is carried out, the state of the bottom, temperature, density and salinity of sea water, water radioactivity, etc. are assessed. An important role in choosing a source is played by the proximity of industrial facilities. Another step in assessing the source of water intake is the calculation of possible risks of water contamination.

The composition of water in open reservoirs depends on the season, such water contains various contaminants, including pathogens. The highest risk of contamination of water bodies is near cities, factories, factories and other industrial facilities.

River water is very turbid, characterized by color and hardness, as well as a large number of microorganisms, the infection of which most often occurs from runoff water. Blooms are common in water from lakes and reservoirs due to the development of algae. Also, these waters

The peculiarity of surface sources lies in the large water surface that is in contact with the sun's rays. On the one hand, it contributes to the self-purification of water, on the other hand, it serves the development of flora and fauna.

Despite the fact that surface waters can self-purify, this does not save them from mechanical impurities, as well as pathogenic microflora, therefore, during water intake, they are thoroughly cleaned with further disinfection.

Another type of water intake source is groundwater. The content of microorganisms in them is minimal. Spring and artesian water is best suited to provide the population. To determine their quality, experts analyze the hydrology of the rock layers. Special attention pay attention to the sanitary condition of the territory in the area of ​​​​water intake, since this depends not only on the quality of water in the here and now, but also on the prospect of infection with harmful microorganisms in the future.

Artesian and spring water outperforms water from rivers and lakes, it is protected from bacteria contained in runoff water, from exposure to sunlight and other factors that contribute to the development of unfavorable microflora.

Normative documents of water and sanitary legislation

Since water is the source of human life, serious attention is paid to its quality and sanitary condition, including at the legislative level. The main documents in this area are the Water Code and the federal law"On the sanitary and epidemiological well-being of the population."

The Water Code contains rules for the use and protection of water bodies. Gives a classification of ground and surface waters, defines penalties for violation of water legislation, etc.

The Federal Law "On the sanitary and epidemiological welfare of the population" regulates the requirements for sources, water from which can be used for drinking and housekeeping.

There are also state quality standards that determine suitability indicators and put forward requirements for water analysis methods:

GOSTs of water quality

• GOST R 51232-98 Drinking water. General requirements to the organization and methods of quality control.
• GOST 24902-81 Water for household and drinking purposes. General requirements for field methods of analysis.
• GOST 27064-86 Water quality. Terms and Definitions.
• GOST 17.1.1.04-80 Classification of groundwater according to the purposes of water use.

SNiPs and water requirements

Building codes and regulations (SNiP) contain rules for the organization of internal water supply and sewerage of buildings, regulate the installation of water supply systems, heating, etc.

• SNiP 2.04.01-85 Internal water supply and sewerage of buildings.
• SNiP 3.05.01-85 Internal sanitary systems.
• SNiP 3.05.04-85 External networks and facilities for water supply and sewerage.

SanPiNs for water supply

In the sanitary and epidemiological rules and norms (SanPiN) you can find what are the requirements for the quality of water both from the central water supply system and water from wells and wells.

• SanPiN 2.1.4.559-96 “Drinking water. Hygienic requirements for water quality centralized systems drinking water supply. Quality control."
• SanPiN 4630-88 "MAC and TAC harmful substances in the water of water bodies of household and drinking and cultural and domestic water use "
• SanPiN 2.1.4.544-96 Water quality requirements for decentralized water supply. Sanitary protection of sources.
• SanPiN 2.2.1/2.1.1.984-00 Sanitary protection zones and sanitary classification of enterprises, structures and other objects.

The composition of water can be different. After all, on the way to our home, she meets many obstacles. There are different methods of improving water quality, the general goal of which is to get rid of dangerous bacteria, humic compounds, excess salt, toxic substances, etc.

Water is the main component of the human body. In the energy-information exchange, it is one of the most important links. Scientists have proved that thanks to the special network structure of water, which is created by hydrogen bonds, information is received, accumulated and transmitted.

The aging of the body and the volume of water in it are directly related. Therefore, water should be consumed every day, making sure that it is of high quality.

Water is a powerful natural solvent, therefore, meeting different rocks on its way, it is quickly enriched with them. However, not all elements found in the composition of water are useful to humans. Some of them negatively affect the processes occurring in the human body, others can cause various diseases. In order to protect consumers from harmful and dangerous impurities, measures are being taken to improve the quality of drinking water.

Ways to improve

There are basic methods for improving the quality of drinking water and special ones. The former consists in clarification, disinfection and bleaching, the latter involves the implementation of procedures for defluorination, iron removal and desalination.

When bleaching and clarification, colored colloids and suspended particles are removed from the water. The purpose of the disinfection procedure is to eliminate bacteria, infections and viruses. Special Methods- mineralization and fluoridation - involve the introduction of substances necessary for the body into the composition of water.

The nature of the contamination determines the use of the following cleaning methods:

1. Mechanical - consists in removing impurities using sieves, filters and gratings of coarse impurities.
2. Physical - involves boiling, UV and irradiation with γ-rays.
3. Chemical, in which reagents are added to the wastewater, which provoke the formation of precipitation. Today, the main method of disinfecting drinking water is chlorination. tap water, according to SanPiN, should contain a residual chlorine concentration of 0.3-0.5 mg / l.
4. For biological treatment special irrigation or filtration fields are required. A network of canals is formed, which are filled with sewage. After cleaning with air, sunlight and microorganisms, they seep into the soil, forming humus on the surface.

For biological treatment, which can also be carried out in artificial conditions, there are special facilities - biofilters and aeration tanks. A biofilter is a brick or concrete structure, inside of which there is a porous material - gravel, slag or crushed stone. Microorganisms are applied to them, purifying water as a result of their vital activity.

In aerotanks, with the help of incoming air, activated sludge is moved into sewage. Secondary settling tanks are designed to separate the bacterial film from purified water. Destruction in domestic waters of pathogenic microorganisms is carried out by disinfection with chlorine.

To assess the quality of water, it is necessary to determine the amount of harmful substances that ended up there after treatment (chlorine, aluminum, polyacrylamide, etc.), and anthropogenic substances (nitrates, copper, oil products, manganese, phenols, etc.). Organoleptic and radiation indicators should also be taken into account.

How to improve water quality at home

To improve the quality of tap water at home, additional purification is required, for which household filters are used. To date, manufacturers offer them in huge quantities.

One of the most popular are filters based on reverse osmosis.

They are actively used not only at home, but also at public catering establishments, in hospitals, sanatoriums, and at manufacturing enterprises.

The filtration system provides for auto-flushing, which must be turned on before filtration begins. By means of a polyamide membrane through which water passes, it is freed from contaminants - purification is carried out at the molecular level. Such installations are ergonomic and compact, and the quality of the filtered water is very high.

Water Treatment: Video