Purification of drinking water and its parameters. Water we drink

Man 70 - 80% consists of water. Loss of even 0.1 parts of water from the body disrupts the normal course of chemical and physical processes. Therefore, it is necessary to maintain a constant water balance in the body. In order for the mineral metabolism in the body of an adult with a normal body weight and good health to be balanced, he needs to consume at least two liters of drinking water per day.

Drinking water is intended for daily unlimited and safe consumption by humans and other living creatures.

Drinking water obtained directly from high-quality natural water sources without the use of water treatment methods and initially conforming to the requirements established for drinking water can be conventionally called “natural drinking water”.

Water, the quality of which at the level of drinking can be achieved only after appropriate water treatment, as a result of which its initial composition and properties change, can be called “prepared drinking water”.

Depending on the location of drinking water and receiving it by consumers can be allocated:
- drinking water in drinking water supply systems (centralized, non-centralized, autonomous, in drinking water supply systems in transport, etc.);
- drinking water obtained using household water purification devices;
- drinking water, packaged in containers: bottles, containers, packages.

Drinking water should not contain sweeteners or chemical additives, calories and sugar. Flavors, extracts and essences extracted from fruits or spices can be added to drinking water, but these additives should be less than one percent of the total weight of the product. Drinks containing additives more than 1% of the total weight, are already defined as non-alcoholic, and not as drinking water.

TYPES OF DRINKING WATER

In nature, there are many types of water. Each of them differs in a number of properties: physical indicators, structure of molecules, chemical composition, biological effect on the human body. The best types of drinking water are: spring water, river water, rainwater, well water.
The best water for constant drinking is spring water.
The types of water that depress health are: snowy water (especially stale water), swamp water, not fresh boiled water (stored for more than a day), city tap water.

Tap water (water from the city water supply, city water supply) supplied for consumption from the tap is delivered to the houses by the utility company for water supply. As a rule, it is water from river water intakes. Often, it is disinfected by chlorine, so it always contains its compounds in significant quantities. Drinking tap water as drinking water, even if it is clear, is highly undesirable. It does not cause rapid harm to health, but slowly eroding it may eventually provoke a lot of quite serious diseases.

To get rid of chlorine, water before drinking should either be defended in an open vessel for at least an hour, or boiled. Before drinking water from the tap as drinking water, it should also be filtered without fail.

To purify water, you can use the following recipes:
Recipe 1. On 1 liter of water, add 1 - 2 teaspoons of apple cider vinegar and honey, 3 - 5 drops of 5% iodine. In such an environment, microbes die in a few minutes.
Recipe 2. On 1 - 3 liters of water put 10 - 15 leaves of mountain ash. Water (even marsh) becomes clean after 2 hours. The leaves can be reused, only after use they should be washed with clean water and, if used, be infused for at least 3 hours. The leaves are dried in the shade and stored in a wooden crate or cardboard box for storage.

Rainwater is well absorbed by the body, contributes to better digestion and assimilation of food, keeps the skin moisture and keeps it in balance. It is excellent drinking water, but on condition that it is clean. The composition of rainwater depends largely on the territory over which the cloud has formed, how heavily the atmosphere is polluted there. Unfortunately, rainwater today can not not only drink, but even wash her head, so much she is polluted.

Spring water is groundwater and groundwater that have access to the surface. Making its way to the surface, the water passes through layers of gravel and sand, which provides it with natural natural filtration. With such purification, the water does not lose its healing properties and does not change the structure and hydrochemical composition. It is excellent drinking water, but on condition that it is clean. Unfortunately, springs, as well as rainwater, are subject to pollution. At present, it is impossible to guarantee the good quality of spring water, since it depends both on seasonal circumstances (showers, floods, groundwater) and on emissions from nearby industrial enterprises.

There are two aquifers: sandy lies at a depth of 15–40 m and is separated from the top layer of soil by clayey layers, which protect it from pollution, and at a depth of 30–230 m and more limestone aquifers, so-called artesian, are located. Artesian water is reliably protected from external pollution and is widely used in the industrial production of drinking water.

Distilled water contains almost no impurities and impurities. It is obtained by distillation in special apparatus - distillers. It is not suitable for drinking, since on the one hand it does not contain the necessary amount of mineral elements, and on the other, it flushes out not only slags and toxins from the body, but also useful substances and trace elements, and therefore can unbalance the body’s work and can disrupt metabolism.

Melt water contributes to the removal of toxins from the body, gives it a strong energy supply. Its properties are maintained for 7 to 8 hours after thawing the ice. Melt water has a whole complex of medicinal properties and has long been widely used in healing practices. It is useful to drink at least 2 - 3 glasses of such water per day.

Natural mineral water according to international standards must meet the following requirements:
- water should come from a natural source, protected from any contamination, and be poured directly into bottles at a distance of no more than 50 meters from the source;
- water must be of natural purity, it is unacceptable to use any methods that can change its original, natural properties. Filters are allowed for cleaning from mechanical impurities.

Mineral water also has a whole complex of healing properties and has long been widely used in the treatment of various diseases.

BOTTLED WATER

The International Bottled Water Association (IBWA) gives it the following definition: “Water is considered bottled if it meets state standards, hygienic requirements for drinking water, is placed in a hygienic container and is sold for human consumption. However, it should not contain sweeteners or additives of artificial origin. Bottled water is divided into three categories: mineral, artificial and drinking.

Mineral water is the water of an appropriately registered underground source (well), with the original composition of mineral substances preserved.

Artificial water is fresh drinking water made using technological methods to simulate the chemical composition of natural mineral or other waters. Artificial mineral waters are obtained by adding chemical components (salts of magnesium, potassium, sodium, iodine, etc.) present in natural mineral waters in the same percentage concentrations to ordinary or distilled water.

Drinking water is divided into two classes:
- drinking water of the first category (table water);
- drinking water of the highest category.

Bottled water can be carbonated or non-carbonated; carbonated is much more in demand than non-carbonated water.

Carbonated drinks are carbonated drinks, characterized by their peculiar pleasant taste and refreshing properties. Aerated drinks are produced either by mechanically introducing and dissolving technical carbon dioxide in a liquid, or by saturating the beverage with natural carbon dioxide released during fermentation.

Carbon dioxide has preservative, disinfecting, disinfecting and antimicrobial properties. It has a detrimental effect on live microorganisms present in drinking bottled water, which is never sterile. Water saturation with technical carbon dioxide is economically beneficial for the producer and the seller, since the carbonation of water increases the shelf life and, accordingly, the sales time is extended.

On the basis of many years of research and observation, contraindications have been identified for drinking carbonated drinking water and other carbonated beverages:
People with chronic diseases of the gastrointestinal tract (gastritis, peptic ulcer, colitis, hepatitis, pancreatitis, etc.) are absolutely contraindicated in the use of such beverages.
Children under 3 years old are advised not to give such drinks at all.
It is not recommended to drink carbonated drinks in large quantities to those who suffer from allergies or are overweight.

The number of fakes of famous brands of drinking water, depending on the region, reaches 20% of the total volume of products sold. Up to 2/3 of all legal bottled water in our country is not produced according to the declared and approved technology. Therefore, in order to buy bottled water relatively safely, do it only in large reputable stores that buy drinking water directly from manufacturers.

Drinking bottled water can be produced:
- using the purification of natural water from a source of drinking water supply, most often of the artesian type;
- by means of tertiary treatment of water from centralized drinking water supply systems;
- with the help of conditioning - artificial mineralization, additional enrichment with vital micro and macroelements.

In the production process, water is first cleaned with several filters - coal and sand, in the next stage, water is passed through special filters that reduce mineralization or, conversely, saturate the water with certain minerals. Then water is disinfected, exposing to ultraviolet radiation, and then saturated with ozone for the same purpose.

After preliminary preparation, the water is poured into bottles, which are also treated with a special solution, disinfected and rinsed with the same water that is poured into the bottle. Cork, which closes the bottle, also undergoes treatment - with ultraviolet light.

Almost the entire process of producing bottled water is automated. The factories of large manufacturers have their own laboratories in which the quality of the produced water is checked every hour. In addition, samples from each batch of produced water are sent for examination to the laboratory of the Center for Hygiene and Epidemiology. Each month, water is submitted for bacteriological analysis, and a detailed examination of the water is carried out every six months.

The quality of domestic drinking water is determined by the requirements of national standards (GOST):
- № 2874-82 “Drinking water. Hygienic requirements and quality control ";
- № Р 51232-98 “Drinking water. General requirements for the organization and methods of quality control ";
- № 27065-86 "Water quality. Terms and Definitions";
- № 17.1.1.01-77 “Protection of nature. Hydrosphere. Use and protection of waters. Basic terms and definitions ";
- № 17.1.1.04-80 “Nature Protection. Hydrosphere. Groundwater classification by water use purposes ”;
- other state standards for determining methods for sampling and drinking water quality for more than 20 indicators;
- rules and regulations SanPiN 2.1.4.1116-02 “Drinking water. Hygienic requirements for the quality of water packaged in containers. Quality control";
- SanPiN 2.1.4.550-96 "Drinking Water";
- SanPiN 2.1.4.1074-01 “Drinking water. Hygienic requirements for water quality of centralized drinking water supply systems. Quality control".

Recommendations for the choice of drinking water:
- Mineral water from underground wells is useful to use periodically, but not constantly, and when buying, choose the most recent bottled water;
- drinking purified table water in bottles, it is also desirable to take the most fresh, because over time its properties deteriorate;
- preference is better to give non-carbonated water;
- for permanent use, spring or well water (from a shallow depth), svezherazlity in bottles, or the most purified and structured tap water will be a good option;
- The bottle must have information on the category of water (drinking, dining, medical-dining, medical), its source (water supply, well number), the manufacturer with the address, chemical composition and registration data.

Categories of organic iron.

Colloid. Small in size, less than a micron, particles, called colloids, are insoluble in water, but very difficult to filter through granular filter materials. The small size and large surface charge pushes colloidal particles away from each other, preventing them from coarsening and creating suspensions in water in suspension.

Bacterial. There are bacteria that use the energy of dissolved ferrous iron in their life processes, which converts it into ferric iron.

Soluble. Chelates are organic molecules that bind iron into complex soluble structures. As an example, it is possible to cite the iron – porphyrin group retaining hemoglobin, which retains magnesium chlorophyll of plants.

Different types of iron manifest their properties in different ways and in most cases it is possible by appearance, without performing tests, to determine which iron prevails in water. Pure water over time, forms a red-brown precipitate. This is the presence of ferrous iron. If the liquidity has a yellow-brown color and a precipitate forms on settling, then it is trivalent. The rainbow film on the surface and the jelly-like mass inside the tubes are bacterial. And if the liquid is colored, but no precipitate is formed, then it is colloidal.

Very rarely, only one type of iron is present in the water. Most often it is a combination of several or all types. The lack of approved methods for determining the amount of organic, colloidal or bacterial iron makes it difficult to choose a method or complex of water purification methods. Only practical experience allows enterprises to choose the right set of measures for water purification, because even in an obvious situation, standard methods often do not work.

Water oxidation is also a chemical indicator. The amount of organic and mineral substances in it, oxidized under certain conditions, characterizes the magnitude of oxidizability.

The magnitude of the oxidizability is determined by the consumption of an oxidizing agent or an equivalent amount of oxygen required for the oxidation of substances contained in 1 liter of liquid. The lowest oxidation rate (up to 3 mg / l O2) is characterized by artesian water. The oxidizability of river water and from reservoirs varies from 2-10 mg / l, reaching higher rates in waters of swamp origin, containing many humic substances. Increased oxidability indicates contamination of the source of industrial or domestic wastewater. A sudden increase in oxidability is also a signal of contamination by its drains. Therefore, the value of oxidizability is one of the common indicators for hygienic characteristics.

Low-contaminated natural waters in water treatment methods determine the permanganate oxidation, the contaminated bichromate oxidation. This characteristic is abbreviated as COD - chemical oxygen consumption. Organic substances of diverse nature and chemical properties are formed under the influence of biochemical processes of intrawater, surface and groundwater, precipitation, industrial and domestic water.

The limits of oxidation fluctuations, from fractions of milligrams to tens of milligrams of oxygen per liter, are highly dependent on the origin of water. Higher oxidizability have surface water compared to groundwater. In surface waters, the most pure of organic matter are mountain rivers (units of milligrams per liter), more “rich” organic matter — swamp rivers (tens of milligrams per liter). In addition to places rich in oil and gas fields, peatlands, swamps, groundwater is the cleanest and amounts to tens of milligrams of oxygen per liter.

Atmospheric water.

The water content in the atmosphere is relatively small - about 0.001% of its entire mass on our planet. The main source of atmospheric moisture are surface waters and moist soil; In addition, moisture enters the atmosphere as a result of water evaporation by plants, as well as respiratory processes of living beings. Water in the atmosphere is in all three aggregative states - gaseous (water vapor), liquid (raindrops) and solid (crystals of snow and ice). Condensation of water vapor leads to the formation of clouds; atmospheric moisture lost as a result of precipitation is replenished due to the supply of new portions of evaporated water. Rainwater, while in the cloud, already contains some salt. In the course of powerful circulation processes carried out in cloud masses, water and particles of salts, soil, dust, interacting, form solutions of diverse composition. According to Academician V.I. Vernadsky, the average salinity of the cloud is about 34 mg / l. Dozens of chemical elements and various organic compounds are found in raindrops. Rain moisture, in contact with atmospheric air, absorbs new portions of salt and dust. A normal 50 mg drop of a rain drop, when falling from a height of 1 km, “washes” 16 liters of air, and 1 liter of rainwater takes with it impurities contained in 300 thousand liters of air. As a result, with each liter of rainwater up to 100 mg of impurities enter the Earth. Atmospheric moisture contains in its composition and microorganisms, protozoa, algae, etc., which is united by the concept "Airplane" .

All of the above prevents the use of atmospheric water as a source of drinking water supply, but in waterless areas it is used by the population for both household and drinking needs.

Surface water.

Surface water quality depends on the combination climatic and geological factors. The main climatic factor is the amount and frequency of precipitation, as well as the environmental situation in the region. Falling precipitation carries with it a certain amount of undissolved particles, such as dust, volcanic ash, plant pollen, bacteria, fungal spores, and sometimes larger microorganisms. The ocean is a source of various salts dissolved in rainwater. It can detect ions of chloride, sulfate, sodium, magnesium, calcium and potassium. Industrial emissions into the atmosphere also "enrich" the chemical palette, mainly due to organic solvents and oxides of nitrogen and sulfur, which are the cause of "acid rain". Contribute and chemicals used in agriculture.

To number geological factors include the structure of the river bed. If the bed is formed by limestone rocks, the water in the river is usually clear and hard. If the channel of impermeable rocks, such as granite, then the water will be soft, but muddy due to the large number of suspended particles of organic and inorganic origin.

As drinking water supply sources most commonly used rivers , which represent the natural runoff of springs, swamps, lakes, glaciers. At the same time, direct feeding of rivers is carried out by rains, during the melting of snow cover, by the meltwater of glaciers, and also by underground sources. River waters are characterized by a large number of suspended substances, low transparency, large microbial contamination.

Lakes and ponds are natural or artificial pits, replenished with water mainly due to precipitation and groundwater. These water sources are less suitable for drinking purposes, since they are significantly susceptible to pollution and have a weak ability to self-purification.

Artificial open water sources include reservoirs that are created by the construction of dams that block the flow of water. The quality of water in reservoirs depends on the composition of river, melt and groundwater, as well as on the condition of the bottom (bed) of the reservoir, which is a flooded area that was previously used in economic circulation.

In general, surface waters are characterized by relative mildness (i.e., a small amount of contained mineral salts), a high content of suspended and colloidal substances, and the presence of microorganisms. These waters are characterized by inconstancy of chemical and bacterial composition, varying rapidly depending on the seasons of the year and precipitation.

The groundwater

Much of the falling rainwater, as well as melt water, seeps into the soil. There it dissolves the organic matter contained in the soil layer and is saturated with oxygen. Deeper are sandy, clayey, limestone layers. In them, organic substances are mostly filtered, but the water begins to be saturated with salts and trace elements. In general, several factors affect the quality of groundwater:

1) The quality of rainwater (acidity, salt saturation, etc.).

2) Water quality in the underwater tank. The age of such water can reach tens of thousands of years.

3) The nature of the layers through which water passes.

4) The geological nature of the aquifer.

Groundwater is subdivided into soil, ground and interlayer.This separation is due to the structure of the earth's crust. All rocks of which the crust forms are divided into permeable to water (sand, gravel, fractured limestone, etc.) and waterproof (granite, clay, etc.), do not let the water. The alternation of these layers and the depth of their occurrence determine the conditions for the formation and composition of underground sources.

Soil water located on the very surface of the earth in the form of hygroscopic film water. The horizon of soil waters is abundant in spring, dries out in summer, and freezes in winter. Therefore, as sources of water supply, soil water is not used.

Groundwater are located in the first aquifer from the surface of the earth, accumulating on the first water-resistant (waterproof) layer at a depth of 1-2 to several tens of meters from the surface.

The most significant quantities in groundwater contain, as a rule, calcium, magnesium, sodium, potassium, iron, and to a lesser extent manganese (cations). Together with the anions that are widespread in water - carbonates, bicarbonates, sulfates and chlorides - they form salts. The concentration of salts depends on the depth. In the deepest waters, the salt concentration is so high that they have a clearly salty taste. The highest quality water is obtained from limestone layers, but the depth of their occurrence can be quite large.

Groundwater is characterized by a fairly high salinity, hardness, low organic content and the almost complete absence of microorganisms. Their quality is varied and inconstant composition, although not to the same extent as the surface water.

These waters are used as sources of drinking water supply mainly in sparsely populated areas (especially in rural areas), water is taken with the help of mine and tubular wells.

Interstitial waters represent the underground waters enclosed between two waterproof layers: lower - a bed and the top - roof. The waterproof roof protects the aquifer (horizon) from precipitation and surface runoff. The feeding of interstratal horizons occurs at the places of their emergence on the earth's surface, sometimes at a great distance from the places of water use.

Interstitial waters are divided into non-pressure and pressure head (artesian). In contrast to groundwater, the mineral composition of interlayer waters depends on the duration of water contact with the aquifer rocks, as well as the composition and properties of the latter. For interstratal waters characterized by significant fluctuations of the mineral composition in different places, the constancy of the composition in different seasons of the year, low content of dissolved oxygen, favorable organoleptic characteristics, the almost complete absence of microflora. The exceptions are cases when the waterproof roof is not solid - thinned, cut through by ravines or river beds, as a result of which groundwater may be polluted by surface run-offs.

Given the stability of the chemical composition, practical sterility, favorable organoleptic properties of interstitial waters, they are used primarily for drinking purposes, because, as a rule, they do not require special treatment, and in some cases disinfection.

Requirements for the quality of drinking water.

When using water for drinking and household purposes, its adverse effect on the body in the form of infectious and non-infectious diseases should be excluded, therefore the requirements for water should be reduced to the following:

1. Water must meet the requirements of the population in its organoleptic properties.

2. Should not contain toxic and radioactive substances;

Different countries have different standards for water quality. In Russia, there are 2 main documents:

For sources of centralized water supply it is Sanitary rules and norms SanPiN 2.1.4.1074-01 "Drinking water. Hygienic requirements for water quality of centralized drinking water supply systems. Quality control" . (Sources of centralized water supply are household water distribution systems comprising the water source itself, water treatment systems and the distribution distribution network).

For sources of decentralized (local) water supply, this is SanPiN 2.1.4.544-96 “Requirements for the quality of water of non-centralized water supply. Sanitary protection of water sources.

SanPiN 2.1.4.1074-01 was created based on the latest developments and data of Russian scientists and taking into account the recommendations of WHO. SanPiN establishes hygienic requirements for drinking water, normalizes the content of harmful chemicals most commonly found in natural waters, as well as those entering the water supply sources as a result of human activities, determines the organoleptic and some physico-chemical parameters of drinking water. By most parameters, the Russian SanPiN meets the recommendations of the WHO and is not inferior to foreign standards, and even surpasses them in some ways. The meaning of the last two columns in the tables from the sections "Inorganic impurities" and "Organic impurities" should be explained.

Hazard Indicator Column. It contains a limiting sign of the harmfulness of substances for which the standard is established.

- s.-t. - sanitary and toxicological (affects the body);

- org. - organoleptic (affects consumer water quality), can be provided with a decoding of the nature of such effects ( zap - changes the smell of water; env - gives the water a color; pen. - causes foam formation; square - forms a film on the surface of the water; pref. - gives water taste; op. - causes opalescence).

Column "Hazard Class". It contains an indicator characterizing the degree of danger to humans of substances that pollute drinking water. Substances are divided into the following hazard classes:

Grade 1 - extremely dangerous;

Grade 2 - highly hazardous;

Grade 3 - dangerous;

Grade 4 - moderately dangerous.

Knowledge of the hazard class of pollutants is extremely important, as they may have a cumulative effect. This means that several particularly harmful substances, even if the content of each of them does not exceed the maximum permissible concentration (MPC), can together make the water dangerous. That is, the water, formally satisfying the norms for all individual parameters, in general, may not be suitable for drinking. Therefore, when several chemical substances belonging to classes 1 and 2 of hazard and rationed by sanitary-toxicological signs of harm are detected in drinking water, the sum of the ratio of the actual concentrations of each of them to the value of its MAC is determined. This amount must not exceed 1.

According to the degree of mineralization, there is a distinction between drinking and balneological waters.

Question. The main indicators characterizing mineral waters

The most important indicators for the classification of mineral

waters are:

- mineralization

- ion and gas composition,

- temperature,

- acidity and

- radioactivity.

Mineral water - these are salts dissolved in water, therefore, they consist of cation ions and anions.

Therefore, allocate:

- over the predominant cation- sodium, calcium, magnesium water;

- by predominant anion- chloride, hydrocarbonate, sulphate waters

Another important indicator is mineralization - this is the content of all substances dissolved in water (ions of iron, calcium, potassium, sodium, arsenic, iodine, bromine, etc.) without gases. It is expressed in g / l (grams per liter). Mineral water includes all waters with a mineral content of more than 2 g / l.

a) medical and dining rooms:

Low mineralized M˂ 2 g / l

Low-mineralized M = 2-5 g / l;

b) drinking and drinking

Mineralized average M = 5-10 g / l

Drinking mineral water causes a change in water-salt and other metabolic processes in the human body, acid-base balance, the functions of various organs. Mineral water at the resort is usually displayed in the pump room (source). In addition, they are bottled.

The therapeutic effect of mineral waters for drinking purposes are manifested by the activity of their ionic composition or by the action of biologically active microcomponents. When using them, it is very important to know the acidity (pH). It is expressed as a hydrogen indicator. Neutral solution has pH = 7. There are:

Highly acidic water pH = 5.5;

Low-acid water pH = 5.5 - 6.8;

Neutral waters pH = 6.8 - 7.2;

Low alkaline water pH = 7.2 - 8.5;

High alkaline water pH = 8.5.

Spa water:

Highly mineralized M = 10-35 g / l;

Brine M = 35 - 150 g / l;

Strong brines M = 150 - 600 g / l;

Very strong brines M ˃ 600 g / l.

Brines with M ˃ 150 g / l are diluted with fresh water to normal salinity.

When vacationing mineral baths, the chemical composition of water, its temperature, mechanical factor - hydrostatic pressure of water, which is enhanced by a shower, hydromassage, cascades, affects the human body. Mineral baths are usually prescribed for diseases of the cardiovascular, nervous system, musculoskeletal system, endocrine system, skin, gynecological diseases, etc.

Temperature is important for the preservation of gases dissolved in water. The higher the temperature, the faster the gases will evaporate.

Stand out:

- cold waters from t ˂ 20˚C

- warm water with t = 20˚ - 36˚С

- thermal waters with t = 37˚ - 42˚C

- high thermal waters with t ˃ 42˚С.

The temperature of mineral waters can sometimes reach 90 ° C and even higher. But you should know that the temperature of the water in the mineral baths should not be higher than 38 ° C, and remember that self-treatment in the baths is unacceptable!

For abbreviation of the chemical composition and some physical properties of mineral waters used kurlov-Carstens formula.

It indicates the content of ions and gas, mineralization, the ratio of the predominant cations and anions (in%), water temperature at the exit, acidity (alkalinity), radioactivity.

Example: kislovodsk Narzan formula

14 ° C pH 6,2

Decryption: carbonate, hydrocarbonate-sulphate, calcium-magnesium water with a salinity of 2.3 g / l, a temperature of 14 ° C and an acidity of 6.2.

Mineral waters have a therapeutic effect on the human body with the whole complex of physical properties and substances dissolved in them. The presence of biological components and special properties often determines the methods of their therapeutic use.

An important role in the complex of spa treatment is played by the internal use of mineral waters (drinking). Their action depends on the composition, temperature, time of intake of mineral water in relation to the time of eating. Assigned single dose (50-300 g) determined by the doctor and depends on the properties of mineral waters, the characteristics of the body and the nature of the disease. Matters the body weight of the patient. Water is used either cold or heated, depending on the disease. After the end of treatment, the long-lasting effect of mineral waters is maintained.

Under non-resort conditions, natural bottled mineral waters are widely used. Most of the bottled water - medical-table. Some mineral waters are only medicinal. They are sold through pharmacies and will be used only according to the testimony of a doctor. The use of mineral waters is also recommended as a repeated course 3-6 months after staying at the resort.

Artificial mineral waters are made of chemically pure salts, but the identity with the natural mineral waters is still not achieved. Only carbonic, sulphide and nitrogen artificial mineral waters are used in Russia.

Drinking water and clean water are not synonymous. Clear water, unlike drinking water, is an indefinite term. For the chemist, "pure water" is a distillate free of impurities; for the fisher, the water in which fish is found; for a microbiologist - water in which bacteria can dwell, and for a production worker - water that is suitable for production processes. Drinking water should always meet certain established standards and guests.

There are several standards for drinking water:

Russian standard defined by the relevant standards and GOST;
WHO (World Health Organization) standard;
US standard and European Union (EU) country standard.

The Russian GOST for drinking water has been in effect since 1982. Now it is supplemented with a newer standard - Sanitary Rules and Norms (SanPiN) 2.1.4.550-96 "Drinking Water".

In accordance with current standards and regulations, the term high-quality drinking water means:

water with the corresponding organoleptic characteristics is clear, odorless and with a pleasant taste;
water with pH = 7-7.5 and hardness not higher than 7 mmol / l;
water in which the total amount of minerals is not more than 1 g / l;
water in which harmful chemical impurities either make up the tenth or hundredths of their MAC, or are completely absent (that is, their concentrations are so small that they lie beyond the limits of the possibilities of modern analytical methods);
water in which there are practically no pathogenic bacteria and viruses.

A short list of inorganic and organic substances, as well as bacteria and viruses in drinking water, which have an adverse effect on the human body, is presented in Table 1.

Table 1. Effect of inorganic and inorganic substances, bacteria and viruses on the human body

Name of the substance, bacteria or virus	Human organs and systems affected by these compounds
Inorganic substances
Beryllium	Gastrointestinal tract
Cadmium	Kidney
Copper	Kidney, liver
Arsenic	Skin, blood; carcinogen
Nitrates and nitrites	Mutations
Mercury	Kidney
Lead	Kidney slowing down
Selenium	Blood
Thallium	Gastrointestinal tract, blood, kidneys, liver
Cyanide	Nervous system
Organic matter
Benzene	Carcinogen
Pesticides (DDT, anachlor, heptachlor)	Carcinogens
Chlorine compounds (vinyl chloride, dichloroethane)	Blood, kidneys, liver
Phenol	Liver, kidney, metabolism
Toluene	Nervous system, kidneys, liver
Bacteria and viruses
E. coli	Gastrointestinal tract
Enteroviruses	Gastrointestinal tract
Hepatitis virus	Liver

Chemicals dangerous to human health most often cause cancer or affect the liver and kidneys and, as a result, the blood, since the kidneys and liver are "the cleaning organs of the human body."

Some compounds of table 1, for example, copper and selenium in low concentrations are needed by the body as trace elements, and in large concentrations are poisons.

Many substances like sulfur, chlorine, iron, are not considered in the table, because the harm they cause is much less compared with the effects of arsenic, mercury, lead and other substances listed above.

With an excess of chlorine or sulfur compounds tap water has an unpleasant odor due to the presence of chloric and sulphurous acids. Such water is not suitable for drinking, it should be cleaned with a filter or buy bottled drinking water in the store.

Excess iron - "rusty" water is also not suitable for drinking; it should also be cleaned.

The presence of microorganisms in drinking water is very dangerous, especially bacteria from the group of Escherichia coli and enteroviruses that infect the gastrointestinal tract, as well as the hepatitis virus. They enter the water from urban sewers and are carried by sewage from fields fertilized with manure. Rains and floods of rivers wash manure into reservoirs, where microflora begins to multiply rapidly. To disinfect water from microorganisms, it is chlorinated.

Table 1 also does not include many organic compounds that are harmful to one degree or another. Some may have an upset stomach, an allergy. Others, such as benzopyrene, gasoline, toxic exhaust products, and pesticides threaten with much more serious disorders.

Pesticides - a group of various substances used in agriculture to combat weeds, insects and rodents, includes about fifty items. Among pesticides, there are relatively harmless, but all are to some degree poisonous, and at least four or five of them contribute to the occurrence of cancer (carcinogenic). From the fields they get into the reservoirs, and from there they can enter the drinking water. If the concentrations of the most dangerous pesticides are very low, of the order of nanogram-microgram per liter, they do not cause significant harm to the body.

Another compound is chlorine. Chlorine disinfects water, because chlorine is a powerful oxidizing agent capable of destroying pathogens. However, in the rivers and lakes from which the water intake is carried out, there are many substances trapped there with wastewater, and with some of them chlorine reacts. As a result, much more unpleasant compounds are formed than chlorine itself. For example, chlorine compounds with phenol; they give the water an unpleasant smell, affect the liver and kidneys, but in low concentrations are not very dangerous. However, chlorine compounds with benzene, toluene, gasoline are possible, with the formation of dioxin, chloroform, chlorotoluene and other carcinogenic substances.

It is not economically feasible to disinfect water without chlorine, because alternative methods of water disinfection associated with the use of silver for this purpose are expensive. An alternative method of water disinfection using ozone was proposed for chlorination, but it turned out that ozone also reacts with many substances in water - with phenol, and the resulting products are even more toxic than chlorophenols.

Another interesting method is to disinfect water using ultraviolet radiation. But this method is also not cheap. It is now being introduced in Petersburg, and it is hoped that in a few years the problems associated with the use of chlorine, fluorine and ozone will be a thing of the past.

Water - the most common in nature, but still not fully studied substance. It is necessary to replenish the water balance in the body (a person needs to drink up to 3 liters of water per day), mineral water treats diseases of the intestines and kidneys, dousing with cold water helps to cope with diseases of the cardiovascular system, calm the nerves and harden the body. The live natural water of the springs, which has not been subjected to technological purification, causes admiration, a desire to quench thirst. The dead water flowing from our faucets can only cause disgust. If the water is cloudy and rusty, then it is better to pass it through the filter for cleaning. And if the water is clear and transparent in appearance? Is this a guarantee that it does not contain harmful impurities? Unfortunately not.

If you drink water from the tap, you should know that it contains organochlorine compounds, the amount of which after the procedure for disinfecting water with chlorine reaches 300 μg / l. Moreover, this amount does not depend on the initial level of water pollution, these 300 substances are formed in water due to chlorination. Of course, there will be no quick consequences from the consumption of such drinking water, but in the future this can seriously affect health. The fact is that when combining organic substances with chlorine, trihalomethanes are formed. These methane derivatives have a pronounced carcinogenic effect, which contributes to the formation of cancer cells.

When boiling chlorinated water in it forms the strongest poison - dioxin. It is possible to reduce the content of trihalomethanes in water by reducing the amount of chlorine used or replacing it with other disinfectants, for example, using granular activated carbon to remove organic compounds formed during water purification. And, of course, we need more detailed control over the quality of drinking water.

Water. Harm and Benefit

Imagine we got sterile water. In such water there are no harmful substances and microorganisms. Is such water valuable for our use? It turns out no. After all, with the water the body should receive a whole complex of mineral substances, without which a person runs the risk of facing many troubles. In drinking water should be not only fluorine and iodine, but also calcium, magnesium, iron, copper, zinc. But that's not all. Water salinity (the amount of salts dissolved in water) is an ambiguous parameter. Studies conducted in recent years have shown an adverse effect on the human body of drinking water with a salinity of more than 1500 mg / l and below 30-50 mg / l. Such drinking water badly quenches thirst, impairs the work of the stomach, violates the water-salt metabolism in the body. Until recently, high mineralization of water — rigidity — was paid attention only because of its influence on the suitability of water for washing hair and washing, as well as on the intensity of scaling when boiling water. Now, thanks to the obtained scientific data, it became clear that water purification is necessary, because the hardness of drinking water is important for maintaining health. For example, a high content of calcium and magnesium salts in water contributes to the development of atherosclerosis, urolithiasis, and causes metabolic disturbances. On the other hand, mortality from cardiovascular diseases is 25–30% higher among people who drink soft water for drinking, containing less than 75 milligrams of calcium and magic per liter of water.

Green and brown stains on dishes - the presence of mineral acids in water: sulfuric and hydrochloric.

Fishy, musty or woody odor - the presence of organochlorine compounds in water.

The formation of dark spots on dishes and silverware, the presence of yellowish, black spots on the surface of the sink - the presence of dissolved hydrogen sulfide in water.

The smell of phenol - the ingress of industrial wastewater in water systems.

Salty taste - high content of magnesium and sodium salts.

The formation of stains on aluminum dishes - high alkali content.

Metallic taste high iron content.

Darkening and corrosion of stainless steel sinks are high in chloride.

Reddish brown sediment - the presence of oxidized iron leached from rusty pipes.

Turbid water is either high air content due to a faulty pump or the presence of methane.

Water from artesian wells and sources

There is a widespread opinion about the healing properties of water from the bowels of the earth. What is it different from the water from the mineral springs of the North Caucasus. It turns out different and very significant. First, the depth of the well. Artesian wells are drilled to pressure waters, for example, in the Moscow region located in coal limestone. The depth of such wells may be different: in the north of Moscow, where the glacier left thick deposits, in the Klinsko-Dmitrov ridge, their depth reaches 200-250 m. To the south of Moscow, in some places, limestone comes to the surface, here artesian wells are the smallest 30-40 m. To the west and east of Moscow, the depth of artesian wells ranges from 60 to 150 m. But in the Moscow region, as well as near other large cities, aquifers with a depth of less than 100 m can no longer be considered bacteriologically safe.

In a cottage or on a summer cottage located in a beautiful area, devoid of any signs of pollution, out of the ground water can flow completely unsuitable for drinking and even life-threatening, in which the concentration of iron, magnesium, fluorine salts exceeds permissible values dozens of times. . Moreover, the concentration of salts in water tends to increase with long-term use of the aquifer. Underground drinking water often has an unpleasant feature - it gets dark in the process of contact with the air. It oxidizes free iron dissolved in water. Clear, clear water, standing in a jug for 10-15 minutes, becomes brown.

Water treatment

Water treatment is designed to remove from the water, both pathogens and harmful chemicals. In addition, water treatment affects the taste properties of water, makes the liquid pleasant to taste. Traditionally, physical, chemical, and sanitary-bacteriological indicators are used to assess the purity of water in a water body or in a water supply source, when it comes to obtaining water for drinking. The physical indicators of pure water include temperature, odors and tastes, color and turbidity. Chemical indicators characterize the chemical composition of water. Typically, chemical indicators include water hardness (pH), salinity (the content of dissolved salts), and the content of major ions. Sanitary-bacteriological indicators include general bacterial contamination of water and contamination with its E. coli, the content of toxic and radioactive microcomponents in water.

But not in all regions water treatment is carried out in the same way, because in various localities in the water contains different chemicals. Depending on the degree of pollution of a water body and the purpose of the water, additional requirements are imposed on its quality. However, there is a set of typical procedures used in water treatment systems and the sequence in which these procedures are used. In the practice of water supply of populated areas with potable quality water, the most common water purification processes are clarification and disinfection. In addition, there are special ways to improve water quality:

water softening (elimination of water hardness cations);
water desalination (reduction in total water salinity);
water deironing (reducing the concentration of iron salts in water);
water degassing (removal of gases dissolved in water);
neutralization of water (removal of toxic substances from water);
decontamination of water (water treatment from radioactive contamination).

Of all the above methods of water treatment in our country is widely used when supplying water through the water supply system to settlements only water clarification and disinfection.

Water clarification

Lightening is a stage of water purification, during which the turbidity of water is eliminated by reducing the content of suspended impurities in it. Turbidity of natural water, especially surface sources during the flood period, can reach 2000-2500 mg / l (with a normal drinking-water rate of not more than 1500 mg / l).

Impurities that are suspended in water have a varying degree of dispersion - from coarse, rapidly settling particles, to the smallest, forming colloidal systems.

Fine-dispersed colloidal particles, having the same electric charge, mutually repel each other and as a result cannot coarsen and precipitate.

One of the most widely used in practice methods for reducing the content of fine impurities in water is their coagulation (sedimentation in the form of special complexes - coagulants), followed by sedimentation and filtration. After clarification, water enters the clean water tanks.

Used in the practice of water supply technological schemes of water treatment contribute to a significant reduction in bacterial contamination of water. Clarification by filtration with preliminary coagulation allows, as a rule, to reduce the content of microorganisms in it by 90-95%. However, among the microorganisms remaining after the water treatment in water can be pathogens (typhoid fever, tuberculosis and dysentery, vibrio cholera, polio and encephalitis viruses), which are a source of infectious diseases. For their final destruction, water intended for domestic purposes should be subject to mandatory decontamination.

Water disinfection

Disinfection is the final stage of the water treatment process. The goal is to suppress the vital activity of the pathogenic microbes in the water. At present, water chlorination is usually used for water disinfection facilities at housing and utilities facilities. In cases of high turbidity and color of natural waters, it is advisable to use pre-chlorination of water, however, this method of disinfection, as described above, is not only not effective enough, but simply harmful for our body.

A more modern procedure of water disinfection is considered to be water purification using ozone. Indeed, ozonation of water is safer than chlorination, but also has its drawbacks. Ozone is very unstable and quickly destroyed, so its bactericidal action is short. But the water must still pass through the plumbing system before being in our apartment. On this way, she waits a lot of trouble. It is no secret that the water pipes in Russian cities are extremely worn out.

In addition, ozone, as well as the products of its interaction with organochlorine, is poisonous, therefore the presence of large concentrations of organochlorine at the water purification stage can be extremely harmful and dangerous for the organism. The method of water ozonation has proven itself very well for treating large masses of water - in pools, in collective use systems, i.e. where more thorough water disinfection is needed.

Of the special methods of water treatment, water desalination is most often used. The scale of water use for drinking and technical needs is such that water purification technology schemes are being more and more actively implemented in water supply practice, making it possible to use the aquatic environment of natural sources that has an increased salinity. In this case, the most common methods of water desalination include distillation, electrodialysis, and ion exchange.

Is it possible to revive the water?

If you want to drink fresh water and avoid unpleasant consequences, then you can not do without water purification.

A filter is a device for cleaning liquids and gases from particles of impurities. Methods of water treatment depend on where you want to use the filter, because devices for cleaning tap water in a city apartment will differ from devices for cleaning water from wells in a country house or in a country house. Cleaning methods also determine the further use of water. The wastewater treatment plants installed at the places where the water enters the house make the water “household”, i.e. water, the use of which will not cause damage to pipes, faucets, appliances and plumbing. In turn, the filters installed at the point of use prepare drinking water. Naturally, the requirements for water purity in the first and second cases are different.

Household filters differ both in the principle of operation and in their design. There are filters on the market that are specifically designed to remove iron, reduce water hardness, filters are bactericidal, fluorinating, combined, reverse osmosis, magnetizing and mineralizing water. And still it is possible to distinguish two main classes of such devices: devices working with running water, and periodic action.

In practice, the two most common methods of water purification: sorption and membrane.

In the first category of filters, the cleaning element is a sorbent material: activated carbon, ion exchange resins. The membrane installed in the filters of the second type plays the role of a sieve. It transmits only water molecules into the tap, and all that is larger is displayed in the drainage. However, there are filters that combine membrane and sorption methods.