Currently, various indicators are used to assess water quality: organoleptic, chemical, bacteriological, biological, helminthological, etc.
but) Organoleptic indicators. To organoleptic indicators with which the definition is made physical properties Waters include: transparency, chromaticity, smell, taste.

Transparency Depends on the number and composition of suspended particles in water. It can deteriorate due to fecal and industrial wastewater in the reservoirs, as well as raindrops and melts that carry a large amount of suspension suspended particles from the surface of the surrounding area. It is believed that the deterioration of the transparency of water is essential from an epidemiological point of view, since such water can cause intestinal infections. The transparency of water is determined using the special font of Sellen, which is read through the water pole, poured into the cylinder. It is expressed in centimeters.

Color water depends often from natural conditions. Water of swampy origin (especially peat swamps) have a gamut of shades from weakly yellow to brown, which depends on the content of humic substances in it. Colloidal compounds of iron give water yellowish-greenish staining. Microflora and microfauna, especially algae during flowering, give water bright green, brown and other paintings, the most diverse color of water acquires as a result of the water of industrial enterprises.

The color of water is determined by colorimetry with the help of a standard scale and expressed in degrees.

Smell may be different: swamp (with decomposition of plant organic substances); Snifferent (from decomposing uncleanness and garbage), fresh grass, earthy, flicker, etc.

Taste It may be unpleasant if household wastewater fall into the water and the impurities in them are discharged. Different specific taste often give water production effluents. Natural waters sometimes have a peculiar taste, which is associated with the conditions of their formation: the salty taste is given by the water chlorides, bitter-sulphate magnesium, binding - sulfate calcium, etc..

The smell and taste is determined organoleptically and estimated in points on the five-point system.

Active reaction of water pH It depends on the presence of ions in it and it. It usually fluctuates in the range of 6.8-8.5.

Water temperature In the range of 7-11 ° is the most favorable person for the human body. In open reservoirs, it changes in accordance with the change in air temperature. Groundwater have a more permanent, relatively low temperature, whose fluctuations indicate the possibility of sub flow of surface water.

A dense or dry residue characterizes the overall mineralization of water.
b) Chemicals. This group includes various chemicals. Some of them have a harmful effect on the human body, others allow you to indirectly judge the pollution of water by organic substances and thereby determine the degree of epidemiological danger of water. Among substances pointing to water pollution by organic substances, the greatest value It has the definition of nitrogen-containing substances (ammonia, nitrites, nitrates).

Ammonia It is formed in the initial stage of decomposition of the substances of organic origin in the water. Its presence even in the form of traces causes a suspicion that fresh uncleans of man and animals fell into the water. And from this point of view, it is an indirect indicator indicating the infection of water by microbes. At the same time, it is found in swampy, peat waters, as well as in ferruginous groundwater. Naturally, in this case it does not have a sanitary value.

Nitrit (A nitrate acid salts) can also be of different origin. The rainwater almost always contains a nitroxy acid in the amount of 0.01-1.7 mg / l. Nitrites can be formed as a result of the reduction of nitrates with denitrifying bacteria, as well as with ammonia nitrification. In the latter case, they acquire a large sanitary value and their presence indicates that ammonia, formed in water as a result of decomposition of organic substances, began to undergo mineralization. Consequently, the presence of nitrites in water indicates a recent contamination by its organic substances of animal origin.

Nitrate (nitric acid salts) are found in unpolluted waters of swampy origin, but they may be in water as a product of ammonia mineralization and nitrite, resulting from rotting organic garbage. The presence of only nitrates in the absence of nitrites and ammonia indicates a long-time, possibly accidental, one-time pollution of water by feces of man and animals. If simultaneously with nitrates in water are ammonia and nitrites, it is a serious sign of constant and long pollution of water. Due to the fact that at present the role of water nitrates in the occurrence of methemoglobinemia, especially in children, is attached to this indicator great importance.

Practically nitrogen-containing substances are determined by colorimetry with the help of photoelectrocolorimeters or by volumetric colorimetry.

Chlorida are a valuable sanitary indicator. They are always kept in urine and kitchen garbage, and therefore, if they are found in water, there is a suspicion of contamination by her household wastewater. However, they can also be in groundwater, since, filtered through the soil containing sodium chloride, it is enriched with chlorides. Chlorides are determined by the method of argenometric titration.

A certain meaning when evaluating water quality plays oxidability - An indicator that characterizes the number of easily oxidizing organic substances in the water. Since the direct definition in water of organic substances is methodically difficult, they are judged by indirectly, according to the amount of oxygen, which went to their oxidation in 1 liter of water. Consequently, this indicator gives a general conditional understanding of the number of organic pollution. Practically oxidation is determined by the method of permanganometry.

Rigidity Water is determined by the presence of soluble salts of calcium and magnesium in it. Distinguish: overall rigidity depending on dissolved salts of coal, hydrochloric, nitric, sulfur and phosphoric acids; disposable (or carbonate), due to the presence of bicarbonates, which, when boiling, falls out as a white sediment; Failed (or constant), depending on salts that do not fall into precipitate when boiling.

The determination of water stiffness is dictated by the need to take into account the economic and household interests of the population, which avoids enjoying tough water, resorting even in some cases to doubtful in sanitation water source, but with soft water. This is explained by the fact that vegetables and meat and meat are poorly welded, the quality of tea deteriorates, laundry laundry makes it difficult, when washing, skin irritation is observed due to the formation of insoluble compounds as a result of substitution in soap sodium calcium or magnesium.

As recent studies have shown, the increased rigidity of water does not have the direct influence on the human body. The total rigidity is determined by complexometric titration. It is expressed by stiffness in milligram-equivalents per 1 liter of water.

In addition to these indicators, in assessing the quality of water of open reservoirs, the definition of the biochemical need of oxygen (BPK5 is a five-day sample), a solution of dissolved oxygen and some others are applied.

With regard to the determination of chemicals that directly affect the human body, it is carried out if there is a suspicion for the presence of a toxic substance or a group of substances in water. The results obtained are compared with established sanitary legislation maximum permissible concentrations (MPC) of harmful substances in water.

in) Sanitary and bacteriological indicators of water quality. The direct detection of infectious diseases in water is difficult in view of the fact that the methods of excretion of pathogenic microorganisms, especially viruses, are complex and do not allow short term Give conclusion about the epidemiological characteristic of water. Therefore, a sanitary and bacteriological assessment is made by indirect indicators that are: 1) microbial number and 2) the content of the intestinal stick. Both of these indicators are generally accepted on the basis of long observations indicating that the more water is polluted, the greater the saprophistic and intestinal microflora and, on the contrary, the smaller it is contaminated (especially the highlights of man and household waste water), the less This water is the number of microbes and, in particular, intestinal sticks, and, therefore, the weaker the possibility of the occurrence of infectious diseases in the use of such water is expressed.

Microbial number (the total number of microbes in 1 ml of water) is an indicative indicator, since all the microbes in the sample are calculated without their identification; It indicates water pollution by any waste fluid, garbage, etc., which are not guaranteed from the content of pathogenic bacteria.

The detection of intestinal sticks in water has a large sanitary value. This is due to the fact that the place of natural habitat is a fat intestine of a person and an animal. In an external environment, it can only fall with feces. Consequently, the detection of intestinal sticks in water indicates contamination by its feces in which there may be, in addition to B. coli, pathogenic bacteria of the intestinal group - causative agents of abdominal typhoids, dysentery, paratifies. Intestinal wand is called an indicator of fecal pollution of water.

In order to find out the degree of epidemiological hazard of water against intestinal infections, it is necessary to establish the intensity of fecal pollution of water, i.e., determine the number of intestinal sticks in water, as the greater the greater B. coli in water, the stronger it is contaminated with feces. Quantitative to the presence of intestinal sticks is characterized by two indicators:
a) Kohl-titer - the smallest amount of water (in milliliters), which contains one intestinal wand,
b) Kolya index - the number of intestinal sticks in 1 liter of water.

IN last years Some authors offer to use for sanitary and bacteriological assessment of water, besides intestinal sticks, fecal streptococcus, Clostridium Perfringens WELENII, bacteriophage. The method of detecting pathogenic bacteria of the intestinal group is being developed using a haptine (nonspecific antigen), etc.

In the study of water water sources, especially open reservoirs, some other indicators and techniques are gaining.

Thus, when studying water in water-sources, especially in open reservoirs, a sanitary and topographic examination is of great importance, whose task is to detect the area of \u200b\u200bthe catchment, which feeds the water, factors that can worsen water quality. The terrain is studied, the composition of the soil, the presence of forest arrays. Characterized placement settlements, industrial enterprises, agricultural use of the territory. Of particular importance is the study of the degree of population of the territory, since the higher the density of the population, the greater the garbage of organic origin is formed and the more realize the possibility of entering the water and the occurrence of water epidemics. It is necessary to obtain information about the use of water reservoir, turning special attention to water transport and fisheries, to use water reservoirs, on the incidence of the population of this area. Hydrometric measurements (depth, flow rate, water consumption, etc.) have great importance.

A substantial role is played by biological analysis, since it is known that in the reservoir large quantities of aquatic plants and animals affect the quality of water. By virtue of this, the aqueous flora and fauna are used as an indicative organisms that are sensitive to changing the living conditions of the reservoir. These biological organisms are called sapros (SAPROS - rotten). There are four sampling zones (polysal polisher, α-mesosatrobial, β-mesosal and oligosal). Each of them corresponds to a certain flora and fauna, as well as the degree of oxygen content in water.

The detection of the eggs of helminths and cyst of intestinal protozoa also has a large epidemiological and sanitary and hygienic value.

In recent years, the study of water on the content of radioactive substances has gained great importance.

1. Assimate general requirements for the quality of drinking water and the hygienic value of its individual indicators.
   1. Send a method for reading analysis and assessing the quality of drinking water at a local and centralized water supply.

1. Source knowledge and skills

1. Know:
   1. Hygienic indicators and quality of drinking water quality (physical, organoleptic, chemical composition) and contamination indicators (chemical, bacteriological - direct and indirect), their scientific substantiation.
      1. The concept and characteristics of centralized (economic and drinking water supply) and decentralized (mine deck E C, Spring Spring ) Water supply systems.
      2. Hygienic characteristics of generally accepted and special methods of quality improvementdrinking water, technical means of their implementation on the head facilities of water pipes with centralized water supply systems.
      3. A set of measures to sanitize the exploitation of headquarters of the water supply (individual elements and a water supply network), as well as wells, cavity.

1. Be able to:
   1. Giving a hygienic assessment of drinking water quality according to sanitary survey of the water supply source and the results of laboratory analysis of water.
      1. Giving a hygienic assessment to different methods of improving water quality and the efficiency of individual structures and means used for this purpose.
      2. Develop a set of measures to improve the quality of water and the prevention of diseases associated with its quality.

1. Questions for self-preparation

1. The impact of the amount and quality of drinking water and water conditions on the health of the population and sanitary living conditions.
   1. The norms of water supply and their rationale.
   2. Infectious diseases whose pathogens are transmitted through water. Features of water epidemics, their prevention.
   3. Diseases of non-infectious origin caused by the use of poor-quality water and their tools for their prevention.
   4. The problem of macro and microelements of water origin. Hygienic value of water rigidity. Endemic fluorosis and its prevention.
   5. Endemic caries. Fluorofrofilaxment of caries of teeth and its meaning in the practice of centralized water supply.
   6. The contribution of domestic hygienists to scientific substantiation and practical implementation Water fluorination in centralized water supply systems of Ukraine. The dependence of water fluorination against climatic conditions of the area.
   7. Water-nitrate methemoglobinesia as a hygienic problem, its prevention.
   8. General hygienic requirements for drinking water quality, their indicators are physical, organoleptic, indicators of natural chemical composition, their hygienic characteristics. Gosstandard on drinking water.
   9. Sources and indicators of contamination and epidemic water safety - organoleptic, chemical, bacteriological, their hygienic characteristics.
   10. Comparative characteristics centralized and decentralized water supply.
   11. Elements of water supply during water fence from artesian and surface reservoirs. Sanitary protection zones.
   12. Generally accepted methods of water purification with centralized water supply (coagulation, upholding, filtering), their essence and structures used for this purpose.
   13. Methods of disinfection of water, their classification, hygienic characteristics.
   14. Chlorination of water, its methods and reagents used for this purpose. Disadvantages of chlorination.
   15. Disinfection of water ozonation and ultraviolet irradiation, their hygienic characteristic.
   16. Special methods for improving water quality, their essence and hygienic characteristics (desalination, depreciation, deodorization, deactivation).
   17. Sanitary supervision methods for centralized water supply (preventive and current). Types of laboratory analysis of the driver - bacteriological, sanitary-chemical (brief and complete).
   18. Sanitary supervision of local water supply systems. Device and operation of mine wells, trapping springs. "Sanation" of the wells.
   19. Methods of reading analyzes and expert evaluation of drinking water.

1. Task (tasks) for self-preparation

4.1. Solve the task: The water is selected from the mine well, the depth of which from the surface of the earth to the surface of the water is 14 m. The woven of the well is made of wood. The well has a canopy, cover, equipped with a cornuroter with a public bucket. The area surrounding the site is not polluted, fenced. Water sample was delivered to the laboratory on June 20 of this year, selected in two flasks for sanitary and chemical and bacteriological research. Water samples are sealing, an accompanying letter is applied to them, which provides data on the state of the well and the conditions in which the water test is selected. The results of the laboratory analysis of water samples are as follows: Transparency - 30 cm for standard font, chromaticity - 400 on a chromocobalt scale; Smell at water temperature 20 and 600 C - missing (1 point); Intensity of the taste - 0 points; The precipitate is missing; Dry residue - 400 mg / l; pH - 7.5; total rigidity - 9 mM-eq / l saa; Iron total - 0.25 mg / l; Sulfates - 80 mg / l; fluorine - 1.2 mg / l; chlorides - 82 mg / l; Ammonium nitrogen - 0.1 mg / l; nitrite nitrite - 0, 002 mg / l; nitrogen nitrates - 20 mg / l; Microbial number - 200 kuo / cm3 ; index bgcp - 4 kuo / cm3 . To give hygienic estimate Water quality in the well and resolve the question of its suitability for economic and drinking use (see Appendix 4).

4.2. Create a sanitary conclusion on the water, the sample of which is selected from the plumbing network. The results of its laboratory study are as follows: transparency - more than 30 cm on the scale of Smelllen; Color - 20.0 according to a standard chromocobalt scale; The smell and taste - do not exceed 2 points; The precipitate is missing; turbidity - 2 mg / l; dry residue 200 mg / l; Iron total - 0.7 mg / l; Sulfates - 96 mg / l; chlorides - 34 mg / l; fluorine - 0.8 mg / l; ammonium nitrogen - 0.28 mg / l; Nitrate nitrates 10 mg / l; nitrite nitrite - 0.001 mg / l; total rigidity of 6.3 mM-eq / l saa; microbial number - 92 kuo / cm3 ; index bgcp - 3 kuo / cm3 (See Appendix 3).

1. Structure of classes

Seminar occupation. After the organizational part, the teacher by surveying students checks the level of their theoretical training according to the above issues for self-preparation and Annex 1. Then, on the example of one of the situational tasks prepared by the department, the teacher sets out the "reading" method of laboratory analysis of water, actively attracting students to this. According to the results of the consideration of the situational problem, students constitute a deployed sanitary conclusion, using the standards given in Appendices 3, 4.

After that, each student receives an individual situational task with a sanitary examination data and the results of laboratory analysis of water and independently constitutes a sanitary conclusion, using the same standards and methods set out in Appendix 5.

1. Literature

6.1. Main:

6.1.1. Goncharuk E.I., Bardov V.G., Garkavy S.I., Yavorovsky A.P. et al. / Communal hygiene / ed. E.I. Pottery: Health, 2006. - p.111-197.

6.1.2. Goncharuk E.I., Kundiev Yu.I., Bardov V.G. et al. / Common hygiene: hygiene propaedeutics / ed. E.I. Goncharuk - K.: high school, 1995. - P. 127-129, 283-300 (on Ukrainian language).

6.1.3. Goncharuk E.I., Kundiev Yu.I., Bardov V.G. et al. / Common hygiene: propaedeutics of hygiene / - k.: Higher School, 2000 - pp. 142-144; 345-364.

6.1.4. Gabovich RD, Poznansky S.S., Shahbazyan G. / Khygen./ - Q.: 1983 - pp. 57-84.

6.1.5. Goncharuk VG, Gabovich R.D., Garkavy S.I. et al. / Guide to laboratory exercises on communal hygiene / ed. E.I. Goncharuk - M.: Medicine, 1990. - P. 110-157.

6.1.4. Dcenko I.I., Denisyuk O.B., Doloshitsky S.L. et al. / Common hygiene. Allowance for practical training / ed. I.I. Datsenko - Lviv.: "Mir", 1992 - pp. 57-59 (for Ukrainian language).

6.1.5. Dcenko I.I., Gabovich R.D. / Preventive medicine. General hygiene with the basics of ecology. / - K.: Health, 1999. - P. 150-220 (on Ukrainian language).

6.2. Additional:

6.2.1. Minh A.A. / Methods of hygienic studies. / - M.: Medicine, 1990. - P. 109-164.

6.2.2. Dcenko I.I., Gabovich R.D. / Basics of general and tropical hygiene. / - K.: Health, 1995. - P. 176-207 (on Ukrainian language).

7. Equipment of classes

1. GOST "Drinking water", SanPiN for central water supply water (1996), sanitary rules on the device of shaft wells and trapping Springs (1975).
2. Situational problem based on the results of laboratory water analysis and an example of a sanitary conclusion.
3. Situational problems of the results of laboratory analysis of water for independent work Students.

Attachment 1

Hygienic characteristics of water supply systems

The centralized and decentralized water supply systems are distinguished.

The centralized system (water supply) includes: water source (inter-plastic pressure or non-pressure water, surface natural reservoir or artificial reservoir), water intake construction (artean borehole, artificial bay with coast water well with filtering grids), water supply (pump or first lifting pumps ), the head facilities of the water supply station, on which clarification, discoloration, disinfection, and sometimes special methods (fluorination, defluorination, dearness, etc.) of improving water quality, reservoirs of its stocks (tanks clean water), Pumping station of the second lift and water supply network - a system of water pipes that deliver water to consumers.

Artesian water (inter-plastic pressure pressure) mostly does not need cleaning, sometimes requires only disinfection, even less often - special quality improvement methods. If the water pipe uses water surface reservoirs, it must be cleaned. The latter is carried out on the treatment facilities of the plumbing station and necessarily provides for clarification, discoloration and disinfection.

To purify water, coagulation is used - the chemical treatment of water with sulfuric acid aluminum by reaction:

Al 2 (SO 4) 3 + 3CA (HCO 3) 2 \u003d 2AL (OH) 3 + 3Caso 4 + 6Co 2

Aluminum hydroxide in the form of quite large flakes adsorbs on themselves the pollutants and humic colloidal compounds in the water, as a result of which the water is covered and discolored. The dose of coagulant depends on the degree of alkalinity of water, the presence of bicarbonate in it, the number of suspended substances and water temperature. With low carbonate stiffness (less than 4ABOUT Add 0.5-1.0% solution of soda or haired lime. In order to accelerate the coagulation, flocculants (polyacrylamide) are added to the water.

After coagulation, the water enters the sumps, and then on the filters, finally, into the tanks of clean water, from which the second lifting pumps are sent to the plumbing network.

After filtration, water necessarily disinfects the ozonation method, UV radiation, or chlorination.

Chlorination is a simple, reliable and cheapest way to disinfect water. At the same time, chlorine gives water an unpleasant smell, and if there is chemical pollution in it (due to the release of industrial enterprises in the water bodies), it contributes to the formation of chlororganic compounds that are invered to carcinogenic effects and chlorophenolic compounds with an unpleasant odor. In this connection, a method of chlorination with preammonation was developed: the preliminary administration of the ammonia solution in the water binds chlorine in the form of chlorins, disinfecting water, and chlororganic and chlorophenolic compounds, and not formed.

Decentralized (local) Water supply is most often carried out from mine or tubular wells, less often by sprinkles. In the wells use groundwater, which lies in the aquifer over the first waterproof horizon. The depth of the occurrence of such water reaches several tens of meters. The well in the conditions of local water supply simultaneously performs the functions of water intake, water-lifting and water treatment facility.

The distance from the well to the consumer of the water should not exceed 100 m. Wells must be placed on the terrain of the terrain above all sources of contamination (bump, underground filtration sites, composts, etc.) at a distance of at least 30-50 m. If a potential source of pollution is located above The terrain relief, relatively well, then the distance between them should be at least 80-100 m, and in some cases not even less than 120-150 m.

The well is a vertical mine of a square or round section that comes to the aquifer. The side walls of the mines are fixed with waterproof material (concrete, reinforced concrete, brick, wood, etc.). The bottom of gravel layer is 30 cm. The above-ground portion of the well, should rise above the surface of the Earth at least 1.0 m. Around the shruck of the well when it is organized by the clay castle of a depth of 2 meters, 1 meter wide and a break in a radius of 2 m With a slope from the well. A drainage tray is arranged for removal of stormwater. Within a radius of 3-5 meters around public wells should be an elevation. Water from the well lift with a pump, or satisfied the covotion with a public bucket. The log cabin is tightly covered with a lid and a canopy is arranged over it.

Sanitation of a shaft well is a complex of events, including repair, cleaning and disinfection of the well, as facilities, in order to prevent water pollution in it. FROMpreventive goalthe well sanitation is carried out before putting it into operation, and then, with a favorable epidemic situation, periodically 1 time per year after cleaning and current or overhaul. Preventive sanitation consists of two stages: 1) purification and repair and 2) final disinfection. In the final disinfection, first the log house and the inner part of the log is treated with an irrigation method (irrigation with a 5% hydrose solution with a solution of chlorine lime or 3% calcium hypochlorite solution at the rate of 0.5 dm3 per 1 m 2 Surbs surface). Then wait until the well is filled with water to the usual level, after which the disinfection of the underwater part of the well is carried out with a volume method (the amount of chlorine lime or calcium hypochlorite at the rate of 100-10 mg of active chlorine per 1 dm3 Water in the well is dissolved in a small amount of water, brighten up the resulting solution into the well, the water in the well is well stirred for 15-20 minutes, the well is closed with a lid and leave for 6-8 hours, without allowing water fence from it).

With an unfavorable epidemic situation (the well is a factor in the distribution of intestinal infections), in the case of a laboratory established fact like water pollution in a well, or visible signs of water pollution by feces, animal corpses, other foreign bodies, spend on epipocations. At the same time, the processing process of the well includes three stages: 1) pre-disinfection of the underwater part of the well with a volume method, 2) purification and repair and 3) final disinfection first irrigation, and then in bulk.

In case of insufficient improvement in the quality of water after the disinfection (sanations), the well is sometimes carried out long-term disinfection of water in the well using metering cartridges. Dosing cartridges are cylindrical-shaped containers with a capacity of 250, 500 or 1000 cm3 Made of porous ceramics in which chlorine lime or calcium hypochlorite are loaded. The amount of calcium hypochlorite with activity is not below 52% calculated by the formula:

X 1 \u003d 0.07 x 2 + 0.08 x 3 + 0.02 x 4 + 0.14 x 5,

where x 1. - the amount of the drug required to load the cartridge (kg), x2 - water volume in the well (m3), x 3 - Debit Well (m3 / h), x 4 - waterborglation (m 3 / day), x 5 - Chloroprotability of water (mg / dm3 ). Before filling, the cartridge is kept in water for 3-5 hours. Then filled with the found number of chlorine-containing drug, add 100-300 cm3 Waters are thoroughly mixed, the cartridge is closed with a ceramic or rubber plug. Thereafter, they are suspended in the well and immersed in water beast of approximately 0.5 m below its top level and 0.2-0.5 m above the bottom of the well.

Capacity - a concreted tank, built near the mouth of the spring in the foot of the hill, the mountains, with an output tube, through which water constantly flows. The tank is divided by a wall of a certain height into two cameras. The first chamber serves as a sump for sand, washed away by the spring, and in the second chamber accumulates the well-defined water, which constantly leaks through the output tube. The sprocket is equipped with a drainage concreted tray with a slope toward the stream, rivers.

Appendix 2.

Hygienic characteristics of water quality indicators

Organoleptic properties of waterwe are divided into 2 subgroups:1) Physico-organoleptic - a set of organoleptic signs that are perceived by the senses and are assessed by the intensity of perception and 2) chemical and organoleptic due to the content of certain chemicals that can irritate the receptors of the respective analyzers and cause certain sensations.

Smell - This is the ability to evaporate in water in the water and, creating a tangible pressure of steam above the surface of the water, irritate the receptors of the mucous membranes of the nose and sinus sinuses. It serves as the appropriate sensation. They distinguish: natural (aromatic, swamp, rotten, fish, herbal, etc.), specific (pharmacy) and, indefinite smells.

Taste and taste - The ability of chemicals available in water after interaction with saliva to irritate taste nipples located on the surface of the language, and predetermine the corresponding feeling. Split salted, bitter, sour and sweet tastes. The rest is the tastes: alkaline, swamp, metallic, petroleum products, etc.

To characterize the intensity of odors, flavors and water skulls, a five-point scale was proposed: 0 - the smell (taste, taste) is absent, it does not detect it even an experienced worer (taster), 1 is very weak, the consumer does not detect, but it feels an experienced workout (tastor), 2 - weak, the consumer feels only when paying attention to it, 3 - noticeable, the consumer easily detects and negatively reacts, 4 - clear, water is unsuitable for use, 5 - very strong, felt at a distance, because of which the water is unsuitable For use.

Dsanpin No. 136/1940 The intensity of the smell and the taste is assessed in terms of breeding (AD).

Unpleasant odors, tastes and water tastes limit its consumption and forced to look for other sources that may be dangerous in epidemic and chemical terms. Specific smell, taste and flavor testify to water pollution due to sewage of industrial enterprises or surface flow from agricultural fields. Natural smell, taste and taste indicate the presence of certain organic and inorganic substances in water, which formed due to the vital activity of aqueous organisms (algae, actinomycetes, fungi, etc.) and biochemical processes of conversion of organic compounds (humic substances), which were in the water from the soil . The smell of water underground sources can be caused by hydrogen sulfide, wells - a chub tree. These substances can be biologically active, indifferent to health, have allergenic properties. Are an indicator of water purification efficiency at water stations.

Color - The natural property of water due to humic substances that are washed out of the soil during the formation of surface and underground water bodies and give water yellow-brown color. Color is measured in degrees using spectrophotometers and photocolorimeters by comparing with color solutions of chromium-cobalt or platinum-cobalt scale, imitating the chromaticity of natural water.

Polluted water may have an unnatural color due to dyes that can get into the water-water waters of light industry enterprises, some inorganic compounds both natural and man-made origin. So, iron and manganese can determine the color of water from red to black, copper - from the pale blue to blue-green. This indicator is calledcoloring water. To measure it, the water is poured into a flat bottom cylinder, a sheet of white paper is placed at a distance of 4 cm from the bottom, the water from the cylinder is drained until the sheet is perceived through its column as white, i.e. It will not disappear in the color. The height of this column in cm and characterizes the color of water.

Turbidity - the natural property of water due to the content of suspended substances of organic and inorganic origin (clay, yals, organic colloids, plankton, etc.). The turbidity is measured by gasometers, spectrophotometers and photocolorometers on imitating kaolin scale, which is a set of suspensions of white Caline clay in distilled water. The turbidity of the water is measured in mg / l by comparing its optical density with the density of standard Kaolin suspensions, according to DSUNPIN 136/1940 - in nephelometric units of turbidity (NOM).

The opposite characteristic of the turbidity of water -transparency - Ability to skip light rays. Transparency is measured by The method of Smelllen: Water is poured into a flat bottom cylinder, at a distance of 4 cm from the bottom there are standard font with letters of size 4 mm, thickness - 0.5 mm. Water from the cylinder is drained until the letters can be read through its column. The height of this column in cm and characterizes the transparency of water.

Color, painted, muddy water causes a person a feeling of disgust that limits its consumption and forcing new sources of water supply. Increased color, turbidity and reduction of transparency may indicate water pollution with industrial wastewater. They may contain organic and inorganic substancesharmful to human health or to form harmful substances during the reagent water treatment (for example, chlorination). Water with high chroma can be biologically active due to humic organic substances. Are indicators of the effectiveness of enlightenment and discoloration of water on water treatment facilities. Weighted and humic substances worsen disinfection of water (prevent the mechanical penetration of the active chlorine into the bacterial cell).

Temperature significantly affects: 1) organoleptic properties of water (smell, taste and taste); The water with a temperature of above 25 ° C has a vomit reflex; According to the international standard, the temperature should not exceed 25 ° C, the best is considered a cool (12-15 ° C) temperature; 2) The speed and depth of the processes of purification and disinfection of water at water stations: with an increase in temperature to 20-25 ° C, the processes of lightening and discoloration of water are improved due to better coagulation, the efficiency of water filtering through activated carbon increases due to the decrease in its adsorption properties, the diffusion of molecules is enhanced Disinfecting chlorine-containing substances inside the bacterial cell, i.e. Decaning improves.

Dry residue (Mineralization General) is the amount of dissolved substances, mainly (90%) mineral salts, in 1 liter of water. Water with a dry residue up to 1000 mg / l is called fresh, from 1000 to 3000 mg / l - salthouse, over 3000 mg / l - salty. Mineralization at the level of 300-500 mg / l is considered optimal. Water with a dry residue of 100-300 mg / l is considered satisfactory mineralized, 300-500 - optimally mineralized, 500-1000 mg / l - increased, but permissible mineralized.

Salon and salt water is unpleasant to taste. The use of such water is accompanied by an increase in the hydrophilicity of tissues, water delay in the body, with a decrease of 30-60% diurea. As a result, the load on the cardiovascular system increases, ischemic heart disease, myocardiosis occurs.t. rofya, hypertensive disease, increases the risk of their exacerbation. Water of increased mineralization can cause dyspeptic disorders in individuals who have changed the residence. The reason for such disorders is the change in the secretory and motor functions of the stomach, irritation of the mucous membranes of the fine and large intestine and the strengthening of their peristalsis. Such water contributes to the development and severity of the flow of urolithiasis and bile disease.

The systematic use of weak-mineralized water leads to a violation of the aqueous-electrolyte homeostasis, which is based on the reaction of the OSSORE-beaded field of the liver. This reaction predetermines the increased emission of sodium into the blood and is accompanied by the redistribution of water between extracellular and intracellular fluid.

Hydrogen Indicator (PN) - Natural property of water due to the presence of free hydrogen ions. Water of most surface reservoirs has a pH in the range from 6.5 to 8.5. The indicator of the groundwater pH ranges in the range from 6 to 9. The coarse waters rich in humic substances are acidic (s pH to 7). Alkaline (with a pH of over 7) - groundwater, which contain many hydrocarbonates.

The change in the active water reaction indicates the contamination of the source of water supply with acidic or alkaline wastewater of industrial enterprises. The active reaction affects the processes of purification and disinfection of water: in alkaline waters, clarification and discoloration will be improved by improving coagulation processes; In an acidic medium, the process of water disinfection is accelerated.

Stiffness common - Natural property of water due to the presence of so-called stiffness salts, namely: calcium and magnesium (sulfates, chlorides, carbonates, hydrocarbonates, etc.). There are general, disposable, constant and carbonate rigidity. Removing, or bicarbonate, rigidity due to CA bicarbonates2+ and MG 2+ which, during boiling water, turn into insoluble carbonates and fall into precipitate for such equations:

Ca (HCO 3) 2 \u003d Caco 3 + H 2 O + CO 2.

Mg (HCO 3) 2 \u003d Mgco 3 + H 2 O + CO 2.

Constant call the rigidity that remains after 1 hour of boiling water and due to the presence of CA chlorides and sulfates2+ and MG 2+ without falling into the sediment.

The overall rigidity of water is expressed in mM-eq / l. Previously used degrees of hardness: 10ABOUT \u003d 0.35 mg-eq / l, 1 mM-eq / l \u003d 28 mg saa / l \u003d 2.8ABOUT .

Water with overall rigidity to 3.5 mG-eq / l (10 ) It is considered soft, from 3.5 to 7 mg-eq / l (10-20 ) - moderately tough, from 7 to 10 mG-eq / l (20-28 ) - tight and over 10 mgq / l (28 ) - Very tough.

The content of stiffness salts Over 7 mg-eq / l gives water of bitter taste. A sharp transition from soft water to rigid can lead to dyspepsia. In areas with a hot climate, use water with high rigidity leads to a deterioration in the flow of urolithiasis. Salt of rigidity worsen suction fat due to their washing and formation in the intestine of insoluble calcium-magnesia soaps. It is limited to the admission of PNCH, fat-soluble vitamins, some microelements (water with rigidity over 10 mG-eq / l increases the risk of disease on endemic goiter). High rigidity assists the emergence of dermatitis due to the irritant action of calcium-magnesia soaps, which are formed during the washed of the skin. With increasing water rigidity, culinary processing of food products is complicated (meat and legumes are worse, tea is poorly brewed, it is formed on the walls of the dishes), the soap consumption increases. The hair after washing becomes hard, the skin is coarse, the fabric is yellow, lose softness, flexibility, ventilation ability due to the impregnation of calcium-magnesia soaps.

Long-term use of soft water, poor calcium, can lead to its deficiency in the body in children living in areas with soft water. On the dental enamel, such children are formed purple stains, which are the result of dentin decalcification. The level of the disease is developing (Kashin-Bek's disease), which is endemic polyhypermicroelement of strontium, iron, manganese, zinc, fluorine. It occurs in areas with low calcium content in drinking water. Water with low content of electrolytes predetermining rigidity contributes to the development of cardiovascular diseases.

Chlorides and sulfates Widespread in nature. They make up most of the dry residue of freshwater. The water bodies come into water due to both the natural washing processes from the soil and the contamination of the reservoir with a variety of wastewater. The natural content of surface reservoirs in the water is insignificant and varies within a few tens of mg / l. Water, which is filtered through the solonchard soil, may contain hundreds and even thousands of mg of chlorides in 1 liter.

Chlorides affect the organoleptic properties of water - give it salty (chlorides) or bitter (sulfates) taste. Considering the large amount of chlorides in the urine and sweat of man and animals, in household wastewater, liquid household waste, wastewater of animal husbandry and poultry complexes, surface drains of them are also used as indirect sanitary and chemical indicators of water epidemic safety. At the same time, chlorides entering water with wastewater industrial enterprises, for example, metallurgical, have nothing to do with probable simultaneous organic and bacterial contaminants.

Iron. In surface water bodies, iron is contained in the form of a resistant huming critic Fe (III), in groundwater - bivalent bicarbonate FE (II). After the subterranean water, the FE (II) surface is oxidized with atmospheric air oxygen to Fe (III) with the formation of FE (III) hydroxide for the reaction:

4Fe (OH) 2 + 2H 2 O + O 2 \u003d 4FE (OH) 3.

The FE (III) hydroxide is poorly dissolved and forms brown flakes in water, which cause its chromaticity and turbidity. With a significant content of iron in water as a result of these transformations, it will acquire yellow-brown color, becoming muddy and acquired a binding metal taste.

Manganese . In concentrations, over 0.15 mg / l,manganese paints water in pink color, gives her an unpleasant taste, paints underwear when washing underwear, forms screaming on the dishes. If the compounds of manganese (ІІ) are oxidation in water, then the negative effect on organoleptic properties is enhanced. With aeration of water, which contains manganese over 0.1 mg / l, a dark brown precipitate MNO will form2 when ozonation in order to disinfect due to the formation of MN salts7+ (permanganate) may occur pink coloring.

Copper. At concentrations, over 5.0 mg / l, copper gives tap water a tangible unpleasant astringent flavor. At concentrations of more than 1.0 mg / l, underwear with washing, corrosion of aluminum and zinc dishes is observed.

Zinc. High content in water zinc impair its organoleptic properties. At concentrations, over 5.0 mg / l, zinc compounds betray a tangible unpleasant astringent flavor. At the same time, opalescence and formation of boiling film may appear in water.

Indicators of safety indicators chemical composition - These are chemicals that may adversely affect human health, causing a variety of diseases.

Chemicals of natural origin (beryllium, molybdenium, arsenic, lead, nitrates, fluorine, selenium, strontium) predetermine the occurrence of endemic diseases. Some of them (molybdenum, selenium, fluorine) belong to biomicroelements, the content of which in the body does not exceed 0.01%, but they are essential for humans. They must have to enter the body in optimal daily doses, with no hypermicroelement agent, or hypermicroelement. Others (beryllium, arsenic, lead, nitrates, strontiums) When excessive admission to the body can manifest toxic effects.

Chemicals that enter water due to industrial, agricultural and domestic pollution of water supply sources. They own heavy metals, such as cadmium, mercury, nickel, bismuth, antimony, tin, chrome, etc. detergents (synthetic detergents or superficially active substances), pesticidi (DDT, HCHC, chlorofos, metaphos, 2, 4-d, atrazin, etc.). Also synthetic polymers and their monomers (phenol, formaldehyde, caprolacts, etc.). Their content in water should not cause the danger to the health of people and their offspring with constant, throughout life, the use of such water. It should guarantee not only the absence of sharp and chronic poisoning, but also the absence, non-specific harmful effects associated with the oppression of the general resistance of the body. It should ensure reproductive health, guarantee the absence of mutagenic, carcinogenic, embryotoxic, teratogenic, gonadotoxic, and other remote consequences. Such content we, hygienists, call the maximum permissible concentration (MPC).

Toxic chemicals while simultaneously presented in water, the combined effect on the human body, the result of which most often is the sum of negative effects, i.e. Adivisive action. To ensure the preservation of health in such a combined action, it is necessary to follow the rule (Averyanova) of comprehensive toxicity: the sum of the ratios of the actual concentrations of substances in water to their MPC should not exceed 1:

where from 1, c 2, with n - actual concentrations of chemicals in water, mg / l.

Indicators that characterize the epidemic safety of waterwe are divided into 2 subgroups: sanitary-microbiological and sanitary-chemical.

Sanitary and microbiological indicators of water epidemic safety.The water safety criterion in epidemic is the absence of pathogenic microorganisms - causative agents of infectious diseases. However, the study of water for pathogenic microorganisms is a rather long, complex and time-consuming process. Therefore, the assessment of the epidemic safety of water is carried out by indirectly indicating the possible presence of the pathogen. For this purpose, two indirect sanitary and microbiological indicators are used - a general microbial number (OMCH) and the content of sanitary microorganisms.

Omch. - This is the number of colonies growing when cropping 1 ml of water by 1.5% meat-pepton agar after 24 hours of cultivation at 37 ° C.

Sanitary and indicative arebacteria in intestinal sticks(BGPP) contained in human and animal feces. BGPP belongs to the bacteria of labor of Echerihia, Enterobacter, Klebsiella, Citrobacter and other representatives of the Enterobacteriaceae family, which are gram-negative sticks that do not form a dispute and capsules. They ferment glucose and lactose with the formation of acid and gas at a temperature of 37 ° C for 24-48 hours and do not have oxidase activity. Selective for BSGP is the Endo's nutrient medium, on which the BGPP grows in the form of dark red colonies with a metal shine (E. Soli), red without shine, pink or transparent with a red center or edges of the colonies.

The presence and amount of BGPP in water indicates the fecal origin of pollution and the possible contamination of water by pathogenic microorganisms of the intestinal group. Quantitatively this indicator is characterizedindex bgkp (number of colony-forming units (Core) - bacteria of the group of intestinal sticks in 1 dm3 waters) and titer bgcp (The smallest amount of water under study in ml, in which one BGPP is detected).

Sanitary and Chemical Indicators of Water Epidemic Safetyindicate the presence of organic substances and the products of their exchange, which indirectly hint on the likelihood of the epidemic hazard of water. This is observed when polluting the water of water bodies with household wastewater, stocks of animal husbandry and poultry complexes, etc. The most indicative of these are the following.

Permanganate oxidability - this is the amount of oxygen (in mg) required for chemical oxidation Easy oxidized organic and inorganic (FE (II) salts, H2 S, ammonium salts, nitrites) compounds that are contained in 1 liter of water. The oxidizing agent is KMNo4 . The smallest permanganate oxidability has artesian water - up to 2 mg about2 per 1 liter In the water of shaft wells, this figure reaches 2-4 mg about2 per 1 liter, in the water of open reservoirs it can be 5-8 mg about2 per 1 l and above.

Bichromatic oxidability, or chemical need for oxygen (COD) - This is the amount of oxygen (in mg) required for the chemical oxidation of all organic and inorganic reducing agents in 1 liter of water. The oxidant at the same time serves K2 CR 2 O 7 . Pure groundwater have a CPD within 3-5 mg / l, surface - 10-15 mg / l.

Biochemical need for oxygen (BOD) - this is the amount of oxygen (in mg) required for biochemical oxidation (due to the activities of microorganisms) of organic substances present in 1 literwater, at a temperature of 20 ° C for or 5 days (BPK5 ), or 20 days (BODtwenty ). BOD 20. also called full (bpkfloor. ). The more water is polluted by organic substances, the higher its BOD. BPK5 in the water of very clean reservoirs less than 2 mg about2 / l (BOD 20 less than 3 mg about2 / l), in water relative to pure water bodies - 2-4 mg2 / l (BOD 20 3-6 mg O 2 / l), in water of contaminated water bodies - over 4 mg2 / l (BOD 20 more than 6 mg O 2 / l).

Radiant oxygen - The amount of oxygen, which is contained in 1 liter of water. It matters to characterize the sanitary mode of open reservoirs. Air oxygen diffuses into water and dissolves in it. Some oxygen is formed due to the vital activity of chlorophilic algae. Along with the enrichment of water with oxygen, it is spent on the biochemical oxidation of organic substances (the processes of self-cleaning of the water branch) and the respiration of aerobic hydrobionts, in particular fish. To prevent deterioration in the processes of self-cleaning and death of hydrobionts, the oxygen content in water should be at least 4 mg2 / l. When entering wastewater containing a large amount of organic substances, the BOD increases and dissolved oxygen is reduced, which is spent on the oxidation of the organic.

Nitrogen ammonium salts, nitrites and nitrates. The source of nitrogen in natural waters is the decomposition of protein residues, animal corpses, urine, faeces. Due to the processes of self-purification of the pond, complex nitrogen-containing protein compounds and urea are mineralized to form ammonium salts, which are further oxidized first to nitrites, and then to nitrates. The self-purification of the reservoir from organic nitrogen-containing pollutants, which fall in the reservoir in the composition of various wastewater and surface drain, also occurs.

In the pure natural waters of surface and underground water bodies, the nitrogen of ammonium salts is within 0.01-0.1 mg / l. Nitrite nitrogen, as an intermediate product of further chemical oxidation of ammonium salts, is contained in water of pure natural reservoirs in very small quantities, not more than 0.001-0.002 mg / l. The increase in their concentration over 0.005 mg / l is an important feature of the source contamination. Nitrates are a final product of ammonium salts. The presence of them in water in the absence of ammonia and nitrites indicates a relatively long admission to the water of nitrogen-containing substances, which managed to mineralize. In pure natural water, the nitrogen content of nitrates does not exceed 1-2 mg / l. In soil waters, a higher content of nitrates may be observed due to their migration from the soil in the event of its organic pollution, or intensive use of nitrogen fertilizers.

General hygienic requirements for drinking water include:

• good organoleptic properties (transparency, relatively low temperature, good refreshing taste, no odors, unpleasant tastes, staining visible to the naked eye floating impurities, etc.);
• the optimal natural mineral composition, which provides good taste quality water, obtaining some of the necessary organisms of macro and trace elements;
• toxicological harmlessness (lack of toxic substances in concentration harmful to the body);
• epidemiological safety (lack of causative agents of infectious diseases, helminthiasis, etc.);
• the radioactivity of water is within the established levels.

State sanitary supervision of centralized water supply is divided into preventive and current. Warning supervision provides for the participation of a doctor's prophylaxis in the choice of a water supply source, a sanitary examination of the water supply project, all of its component elements, sanitary protection zones, supervision of its construction and commissioning.

Before the introduction of a constructed water supply, sanitary protection zones are determined:

The zone of the harsh regime, which includes a certain part of the water area of \u200b\u200bthe reservoir at the place of water intake, up and downstream, the territory around the water treatment facilities, around the location of the artesian well;

The area of \u200b\u200brestrictions - the territory on which the construction and use of objects that can pollute this territory and reservoir are prohibited;

The observation zone, which includes the entire territory, on which the surface source of water supply is flowing, or is the power zone of artesian waters.

Along the water supply network, a sanitary-protective strip is envisaged.

The current sanitary supervision is carried out by in-depth (in repairs, reconstructions) of a planned periodic, sporadic, and sometimes (with coarse sanitary disorders, or the emergence of intestinal infectious diseases) and emergency sanitary surveys. Such a survey is necessarily complemented by the selection of water samples and its laboratory study. The results of this study are estimated by comparison with the hygienic standards of GOST 2874-82 "Drinking water (quality requirements)" and dsanpin No. 136/1940 "Drinking water. Hygienic requirements for the quality of water of centralized economic and drinking water supply "(Appendix 3).

The results of laboratory analysis of water samples from local water supply sources are estimated according to " Sanitary rules On the device and content of wells and coatings of spring, used for decentralized economic and drinking water supply "No. 1226-75 (Appendix 4).

Appendix 3.

Requirements for the quality of drinking water with centralized water supply (extraction from GOST 2874-82 "Drinking water. Hygienic requirements and quality controlfrom tV "and Dercianpin No. 136/1940" Drinking water. Hygienic requirements for the quality of water of centralized economic and drinking water supply ")

Apply to tap drinking water with centralized economic and drinking water supply

Organoleptic performance indicators of drinking water

	Standards (no more)
		GOST 2874-82.	Dsanpіn
Physical and organoleptic
Smell, points
Turbidity, mg / l		0,5 (1,5) **
Color, hail.		20 (35) ***
Tsp, points
Chemical and organoleptic
Hydrogen indicator, pH, ranging, units.	6,0-9,0	6,5-8,5
Iron, mg / l	0,3 (1,0)
Stiffness Total, MEK eq / l	7,0 (10,0)	7,0 (10,0)
Sulfates, mg / l		250 (500)
Dry residue (Mineralization Total), mg / l	1000 (1500)	1000 (1500)
Polyphosphates residual, mg / l
Chlorides, mg / l		250 (350)
Copper, mg / l
Manganese, mg / l
Zinc, mg / l
Chlorophenols, mg / l		0,0003

* - index of breeding, pr (to disappearance of smell, taste),

** - Nephlateometric units of turbidity, it,

*** - The values \u200b\u200bindicated in the arms are allowed taking into account the specific situation.

Epidemic Safety Indicators Drinking Water

Indicators, Units of Measurement	Standards
		GOST 2874-82.	Dsanpіn
Microbiological
Number of bacteria in 1 ml of water (general microbial number, omch), CFU / ml	Not more than 100.	No more than 100 *
The number of bacteria of the group of intestinal sticks (coliform microorganisms), i.e. Index BGKP, Come / l	Not more than 3.	No more than 3 **
The number of thermostable intestinal sticks (fecal colors), i.e. Index FC, CFU / 100 ml		Not ***
Number of pathogenic microorganisms, Come / l		Not ***
The number of kolya phages, boe / l		Not ***
Number of pathogenic intestinal simplest (cells, cysts) in 25 liters of water		Not
Number of intestinal helminths (cells, eggs, larvae) in 25 liters of water		Not

* - for 95% of water samples in the plumbing network, which is studied throughout the year,

** - For 98% of water samples, which enters the water supply network and is investigated throughout the year. If the BGKP index is exceeded at the identification stage of the colonies that have increased, are additionally exploring for the presence of fecal circles-forms,

*** - If fecal circles are revealed in 2 consistently selected samples, it should be started for 12 hours of water research for the presence of causative agents of infectious diseases of bacterial or viral etiology (by epiraditsis)

Toxicological indicators of harmlessness of the chemical composition of drinking water

Indicators	Standards (no more), mg / l
		GOST 2874-82.		Dsanpіn
Inorganic components
Aluminum			0,2 (0,5) *
Barium
Beryllium	0,0002
Molybdenum	0,25
Arsenic	0,05		0,01
Polyacrylamide residual
Selenium	0,001		0,01
Lead	0,03		0,01
Strontium
Nickel
Nitrate	45,0		45,0
Fluorine: І-ІІ climatic belt ІІІ climate belt Iv climate belt
Organic components
TRIGALOALMETHANS (TGM, Amount) Chloroform Dibromhloromethane Tetrachlorouprode		0,06 0,01 0,002
Pesticidi (sum)		0,0001 **
Integral indicators
Permanganate oxidability
Common organic carbon

* The value indicated in brackets is allowed in the case of water treatment with reagents that contain aluminum,

** The list of controlled pesticides is set to the specific situation.

Drinking water radiation safety indicators

Indicators	Standards (no more), BK / L
		GOST 2874-82.	Dsanpіn
General volumetric activity of α-emitters
General volumetric activity of β-emitters

Note: For special regions, the radiation safety regulations of drinking water are coordinated by the chief state-owned sanitary doctor of Ukraine

Indicators of the physiological use of mineral composition

Indicators, Units of Measurement	Standards
		GOST 2874-82.	Dsanpin
Mineralization Total, mg / l		From 100.0 to 1000.0
Stiffness Total, MEK eq / l		From 1.5 to 7.0
Alkalinity General, MEK eq / l		From 0.5 to 6.5
Magnesium, mg / l		From 10.0 to 80.0
Fluorine, mg / l		From 0.7O 1,5

Appendix 4.

Requirements for the quality of drinking water with decentralized water supply (extracting from "sanitary rules on the device and content of wells and cassocks of spring products used for decentralized economic and drinking water supply", No. 1226-75).

1. Organoleptic Indicators:

Smell, points, no more than 2-3

Takes, points no more than 2-3

Transparency, see no less than 30

Turbidity, mg / dm 3 no more than 1.5

Color, degrees no more than 30

Temperature, ° C 8-12

Appearance Lack of visible impurities

1. Bacteriological indicators of epidemiological safety:

Microbial number, kuo / cm3 no more than 200-400

Kolya index, kuo / dm3 no more than 10

1. Sanitary and chemicals of epidemic security:

Permanganate oxidation, mg about2 / dm 3 no more than 4

Ammonium nitrogen, mg / dm3 no more than 0.1

Nitrogen nitrite, mg / dm3 no more than 0.005

Nitrogen nitrates, mg / dm3 no more than 10.0

Chlorides, mg / dm 3 no more than 350

4. Chemical and organoleptic indicators:

Dry residue, mg / dm3 1000 (1500)

Stiffness, mM-eq. / Dm3 saa no more than 10

Iron, mg / dm 3 0.3 (1.0)

Sulfates, mg / dm 3 no more than 500

5. Indicators of harmability in chemical composition:

Fluorine, mg / dm 3 0,7-1.5

Nitrates, mg / dm 3 no more than 45.0

Other chemicals within the limits of extremely permissible concentrations (MPC) according toa NPIN No. 4630-88.

Appendix 5.

Methods of hygienic assessment of water quality according to sanitary examination and

the results of a laboratory study (the "Reading" method of water analysis)

The technique (algorithm) "reading" water analysis consists of 7 stages.

At the first stage Set the type of requirements for water quality:

The first type is the requirements for the quality of drinking water tap water with centralized economic and drinking water supply. This water should be benign and respond to the indicators of the current standard (GOST 2874-82 "drinking water. Gigie. netical requirements and quality control ", Dsanpin No. 136/1940" Drinking water. Hygienic requirements for the quality of water of centralized economic and drinking water supply. "

The second type is the requirements for the quality of the well (spring) water. It should also be benign and meet the requirements of "sanitary rules on the device and the content of wells and coating of spring, used for decentralized economic and drinking water supply No. 1226-75.

The third type is the requirements for the quality of water sources (underground and surface) centralized economic and drinking water supply. GOST 2761-84 "Sources of centralized economic and drinking water supply are regulated. Hygienic, technical requirements and regulations. "

The fourth type is the requirements for the quality of hot water that must meet the requirements of "sanitary rules for the design and operation of centralized hot water systems No. 2270-80."

In the second stage Define the tasks: make a conclusion about the quality of drinking water tap or well water, evaluate the quality and efficiency of water treatment on the structures of the plumbing station, to establish the cause of caries or fluorosis in the population, to establish the reason for the development of methamoglobinemia in children and people of old age, to find out the cause of the mass infectious disease, Decide on the impact on the quality of drinking water of new reagents, which are used in water stations or new polymeric materials, of which the designs of water treatment plants, water pipes, and the like are manufactured.

In the third stage Determine the program and volume of laboratory research. For the output of the quality of drinking tap water (from the crane or street water treatment column), physico-organoleptic (smell, taste and taste, chromaticity, turbidity) and sanitary-microbiological (microbial number and if index) should be studied according to GOST 2874-82. For the conclusion about the quality of well water according to "sanitary rules ..." N 1226-75, physico-organoleptic (smell, taste and taste, chromaticity, turbidity), chemical and organoleptic (dry residue, total rigidity, iron content, active reaction) , Sanitary-microbiological (microbial number and cell index), sanitary-chemical (permanganate oxidation, nitrogen content of nitrates, nitrites and ammonia), indices of harmlessness in chemical composition (fluorides, for example). For clarification possible cause Caries or fluorosis should be determined by the fluorine content in drinking water, water-bearing methemoglobinemia - the concentration of nitrates, infectious disease - to carry out bacteriological or virological studies, the influence of polymeric materials - the corresponding chemical analyzes and other.

At the fourth stage Check the completeness of the presented materials and the timing of research.

If the water test is selected at a plumbing station, from a waterstered column or a shaft well, data of sanitary (sanitary and topographic, sanitary and technical, sanitary and epidemiological) surveys and the results of a laboratory water study according to the research program should be given.

If the water test is selected from the plumbing crane, the results of a laboratory water study according to the relevant research program should be given.

Bacteriological studies should be carried out for 2 hours after sampling or subject to storage in the refrigerator at 1-8 ° C - no later than after 6 hours. Physico-chemical analysis is carried out for 4 hours after taking the sample or subject to storage in the refrigerator at 1-8 ° C - no later than 48 hours.

At the fifth stage Analyze the sanitary survey data and make preliminary conclusions: is there reason to suspect that water can be contaminated, poor-quality, epidemicly dangerous, or whether there are conditions for water pollution in the water source, well, water treatment column.

On the sixth stage Analyzes the data of the laboratory study of water for each group of indicators in such a sequence: 1) physico-organoleptic, 2) chemical-organoleptic, 3) Indicators of harmlessness for chemical composition, 4) sanitary-microbiological and 5) sanitary and chemical indicators of epidemic security. In this case, give a qualitative and quantitative assessment to each indicator. For example, the total rigidity of water is 9 mG-eq / l. In the output, we indicate: "Water is rigid, with the overall rigidity of above 7 mg-eq / l." If the dry residue of water is 750 mg / l, then we note: "fresh water, since a dry residue is up to 1000 mg / l, increased mineralization." If the smell is 2 points, the taste is 2 points, transparency - 30 cm, turbidity - 1.5 mg / l, chromaticity - 20 degrees, the conclusion: "Water without smell, without tastes, transparent, without color, i.e. It has pleasant organoleptic properties and according to this group indicators meets GOST 2874-82. "

At the seventh stage The doctor makes a general conclusion about the quality of the water, respectively, and, if necessary, gives recommendations for improving its quality.

Water and water hygiene

Water, along with air and energy, refers to the number of the most important natural resources Our planet. The combination of all water sources on the ground - oceans and seas, rivers and lakes, ponds and swamps, gravitational and groundwater - called hydrosphere.

The total amount of water on Earth is estimated by a number of 1386 million km 3, and the area of \u200b\u200bthe oceans and seas is 2.5 times higher than the land area. However, almost 98% of the water of the planet are represented by salt water of the oceans, seas and lakes with high levels Mineralization. The share of freshwater is about 2.5% or 35 million km 3. Most of the planet's fresh water is difficult to access. About 70% of it is concluded in the glacial seals of polar territories and mountainous arrays, as well as groundwater in the upper part of the earth's crust at different depths, as a rule, not lower than 150 - 200 meters, as they turn into greater depths due to high mineralization In salty water. The volume of groundwater is approximately 100 times the total volume of lakes, rivers and swamps. The largest fresh reservoirs of the world - Lake Baikal (Square of the Mirror 24 thousand km 2, depth 1741 m) and Tanganica (18.9 thousand km 2 at a depth of 1435 m). By the area of \u200b\u200bthe mirror, the largest lake of the world is the top (North America) - 82680 km 2. total area Swamps on the planet of about 3 million km 2.

Water is the only natural liquid existing on the ground surface in huge quantities. Only this substance in nature exists in all three aggregate standings: liquid, solid and gaseous, due to various interaction between water molecules at different temperatures.

The cycle of water in nature includes three main "loops": surface drain - water becomes part of surface water; evaporation - transpiration - water absorbed soil, is held as capillary water, and then returned to the atmosphere, evaporating from the surface of the Earth, or is absorbed by plants and stands out in the form of vapors during transpiration; Ground waters - water falls under the ground and moves through it, having fun and springs and, thus, again falling into the surface waters.

Water value for human life support.

Water is necessary for household, sanitary and hygienic and production needs of the population. Water is an important health (hardening) and therapeutic factor (aqueous physiotherapeutic and balneological procedures).

The human body contains 70-80% water. To maintain physiological processes, constant replenishment of the lost amount of water is necessary, since even a small loss of water leads to serious health violations.

According to WHO, the need for a person in drinking water is 2.2 liters per day. Water enters the body with food products (0.6 - 1.2l), when drinking (1.5 l) and as a result of oxidation of food substances (up to 0.5 l). Water adopted with food longer delayed in the body than dug on an empty stomach. Water stands out through the kidneys (1.5 liters), from then (400-600ml), with exhaled air (350-400ml), with a fee (100-150ml). Water release depends on the nature of used food, salts content. Thus, sodium ions contribute to the accumulation of water, and potassium ions - its allocation.

Self-cleaning of water bodies.

The pollution arriving in water causes a violation of natural equilibrium. The ability of the reservoir to withstand this violation is to be released from infiltration made and is the essence of the self-purification process. Self-cleaning is a complex complex of physical, physicochemical, chemical and biochemical phenomena.

Water supply systems.

Water supply - supply of surface or groundwater water consumables in the required quantity and in accordance with the target water quality indicators in water bodies. Engineering facilities designed to solve water supply problems are called water supply system, or plumbing.

There are centralized and local water supply systems inhabited areas. With a centralized system, water is supplied to consumers through pipelines in the form of an orange water supply system and street (in the form of water treatment columns), with a non-centralized (local) consumer takes water directly from the water source without a distributing network.

Centralized water supply from underground water sources: Water rises with wells and is supplied to a plumbing distribution network without cleaning. Centralized water supply from open reservoirs: Water rises from an open reservoir using water intake structures, subjected to cleaning and disinfection on the head facilities of the water supply system and only after that is fed to the distribution network.

Unscentralized Water Supply: Water is assembled with shaft or tubular wells, coatings of spring and infiltration wells or galleries. The location of the water intake structures is chosen at an unpolluted area, removed by ≥50 meters above the stream of soil from existing or possible sources of pollution - cesspools and pit, fertilizer warehouses and nadogymicates, enterprises of the local industry, sewer structures, etc. water intake facilities should not be arranged In areas of flood waters, in wetlands, closer than 30 meters from highways with intensive traffic movement.

Shaft (ground) wells Designed for the preparation of groundwater from the first non-pressure aquifer and consist of a mine, a manpower, barrel and a water receiver. The head board (≥ 0.7-0.8 m above the surface of the Earth), which serves to protect the mine from pollution and water lifting should have a lid. At its perimeter, a clay "castle" should be made with a depth of 2m and 1M width of 1m and a slice of stone, bricks, concrete or asphalt by a radius ≥ 2 m with a flap in the side of the cuvette. Around the well there must be a fence, and the bench for the buckets is suitable near the well. Mine walls must be waterproof. The water treatment part of the well, serving for the influx and accumulation of groundwater, should be bundled in aquifer. The bottom of the well to filter the incoming water is covered with gravel. Watering the water from a mine well is carried out with the help of a pump, a gate or "crane" with a public, firmly attached bary or a bucket.

Tubular wells (wells) are designed to obtain groundwater from aquifer and are small (up to 8m) and deep (up to 100m or more). The tubular wells consist of casing pipes of various diameters, pump and filter. The headband of the tubular well should be higher than the surface of the earth by 0.8-1.0 m, is sealed, have a drain pipe equipped with a hook for hanging a bucket. A clay waterproofing "castle", a slope with a slope of 10 0 from a well and a bench for buckets are arranged around the head. Water rise is made using pumps.

Cappothy - These are special chambers made of concrete, brick or wood, designed to collect groundwater leaving on the surface rodnikov (keys). Spring capping should have waterproof bottoms and walls (with the exception of a wall from aquifer), a waterproofing lock, a hatch with a lid, a waterflection pipe with a hook for hanging a bucket. Nearby is a bench for buckets. In order to protect the travelers from the sand drift, a filter is satisfied with the water flow side. Traffic chambers must be placed in the pavilion, the territory of which is fenced.

Within a radius closer than 20 m from the well or trapping of the spring, car wash, water of animals, washing, linen of linen and any activities that contribute to water pollution are not allowed.

Disinfection of water.

Dose chlorine required for water chlorination is determined based on the value chloropiness water. It consists of two magnitudes: chloro-absorption and residual chlorine.

Chlorine-absorption- Chlorine, which is consumed during chlorination of 1 dm³ of water for 30 minutes for oxidation of organic substances.

Residual chlorine-Comecy chlorine that has not entered into the reaction of the compound in the chlorinated water. To ensure the reliability of the disinfecting effect, the residual chlorine content is needed in water in an amount of 0.3-0.5 mg / dm³.

Methods for determining chloropromicity in field conditions.The working dose chlorine for chlorination in the field is determined by the experimental way.

In 3 cups poured 200 cm³ of the water under study, added to the 1st glass of 0.1 cm³, in the 2nd 0.2 cm³, in the 3rd 0.3 cm³ of 1% of the chlorine lime solution. The contents of the glasses are stirred with glass chopsticks and leave for 30 minutes.

After 30 minutes. Add to each glass of 5 cm³ 5% solution of potassium iodide, 5 cm³ 20% solution of hydrochloric acid, 1 cm³ 1% starch solution and stirred.

In the presence of residual chlorine, water is painted in blue. Painted water titrated 0.01 n. Sodium thiosulfate solution to discoloration. The content of residual chlorine is determined by the formula:

x \u003d n × 0,355 × 1000 × 1 / v, mg / dm³, where

n-volume 0.01 n. Sodium thiosulfate solution that has come to titration, cm³, 0.355 chlorine content corresponding to 1 cm ³ 0.01 n. Sodium thiosulfate solution, 1000-coefficient to recalculate in cubic centimeters, V-volume of water sample. Taken to analyze.

To calculate the working dose of chlorine lime necessary for the chlorination of water, the sample is chosen in which the residual chlorine content is in the range of 0.3-0.5 mg / dm³. The calculation of the required dose for 1 dm³ is carried out by the formula:

x \u003d 5n, cm³, where

n-volume 1% chlorine lime solution added to a glass with a capacity that meets the requirements of the residual chlorine content.

Methods for determining chloropromic acidity at water stations.

The chlorine lime contains 20-30% of the active chlorine, but under the action of time, temperature, its light is reduced, so it is necessary to check the content in it of active chlorine before using it. There is a iodometric method for verification.

To chlorination of water, a chlorine lime solution is used containing in 1 cm³ 1 mg of active chlorine. After establishing the content of active chlorine in 1% solution, a working solution of chlorine lime is prepared, containing 1 mg of active chlorine in 1 cm³ by diluting 1% solution.

The amount of the original 1% solution of chlorine lime, which must be taken to prepare the required volume of the working solution containing 1 mg of the active chlorine in 1 cm³, are calculated by the formula:

x \u003d n / v, cm³, where

n-Number of active chlorine contained in 1 cm³ of the initial solution, mg, V-required volume of working solution, cm³.

Water sampling

Objects of research

The objects of the study are water of various water bodies:

Waste;

Waste on the cleaning and disinfection stages;

Fresh and sea surface reservoirs used for recreational purposes, as well as as sources of drinking water supply;

Swimming pools;

Underground water sources;

Drinking (water supply; water, packaged in tanks, etc.);

From decentralized water sources.

1. Wastewater.

The wastewater entering the treatment facilities is investigated to study the spectrum of enteroviruses circulating among the population, and by epidemic testimony.

Wastewater at the cleaning and disinfection stages are investigated to study the efficiency of wastewater treatment facilities regarding pathogens of intestinal viral infections in accordance with the sanitary-epidemiological rules and sanpine regulations 2.1.5.980-00 "Hygienic requirements for surface water protection".

2. Water surface reservoirs

Water fresh reservoirs are investigated for viral pollution in order to study self-cleaning processes, when choosing surface reservoirs as water sources for centralized economic and drinking water supply, the establishment of sanitary protection zones, according to epidemic testimony.

The water control of marine and fresh water reservoirs is carried out at the level of pollution using them for recreational purposes in accordance with the sanitary and epidemiological rules and regulations of SanPiN 2.1.5.980-00 "Hygienic requirements for the protection of surface waters", according to epidemic testimony.

3. Water of underground and sources.

The water of the underground and sources is examined for the presence of viral contamination when choosing a source of economic and drinking water supply, controlling its quality in accordance with GOST 2761-84 "Sources of centralized economic and drinking water supply", by epidemic testimony.

4. Water swimming pools and water parks.

Control over the level of virus pollution of water swimming pools is carried out in accordance with the requirements of sanitary and epidemiological rules and SanPiN 2.1.2.1188-03 standards. "Swimming pools. Hygienic requirements for device, operation and water quality. Quality control", SanPine 2.1.2.1331-03 " Hygienic requirements for the device, operation and quality of water parks, "according to epidemic testimony.

5. Drinking water.

Drinking water is investigated for the presence of viral contamination in accordance with the requirements of sanitary and epidemiological rules and sanpine standards 2.1.4.1074-01 "Drinking water. Hygienic requirements for the quality of water of centralized drinking water supply systems. Quality control", SanPine 2.1.4.1116-02 "Drinking water . Hygienic requirements for water quality packaged in capacity. Quality control ", in accordance with the Water Study Program, approved by the Chief State Sanitary Physician of the City, District, Subject of the Russian Federation, for epidemic testimony.

6. Water control of decentralized sources.

The study of the water of decentralized sources is carried out in accordance with the sanitary epidemiological rules and the standards of SanPiN 2.1.4.1175-02 "Hygienic requirements for the quality of water of non-centralized water supply. Sanitary protection of water sources", by epidemic testimony.

Sampling methods

1. Water from a plumbing network, RFB, wells, wells, swimming pools, bottled water is taken in a volume of 5 - 10 liters for the method of concentrating viruses using filtration membranes (MUK 4.2.2029-05). In addition, the use of polyamide membranes with positive potential (MMPA +) is recommended that one order increases the effectiveness of the concentration of hepatitis A. virus

2. Waste water, water surface reservoirs are passed through the installation with flieslinic packages with macroporous glass for 3 to 7 days. During the rebel incidence of hepatitis

And it is advisable to use the method of concentrating viruses from the water of the distribution network using flieslinic packets with macroporous glass, with the installation of them minimally for 3 days, which allows you to explore a cumulative sample.

Sampling Equipment

For the selection of point samples at a given depth, batter is used.

It is allowed to select water bottle. The bottle is closed by a plug to which the cord is attached, and insert into a heavy rim or it hangs the load on the cable (cord, rope). The bottle is lowered into the water in advance the selected depth, then the plug is removed using the cord, the bottle is filled with water to the top, after which it is removed. Before closing the bottle, the cork layer is drained so that a small layer of air remained under the tube.

It is advisable to apply special bottles for sampling, for example, bottles of pumping air.

Water sample from a small depth (especially in winter) is taken by a bottle attached to the sixth.

To study the vertical profile of water, a glass with divisions, a plastic cylinder or a stainless steel cylinder, open at both ends, is allowed to use a layered structure. At the sampling point, the cylinder before lifting to the surface is closed at both ends with a special device (control cable).

General rules Sampling from various water bodies

For selection of water sampling, disposable dishes or sterile multiple use capacities made from materials that do not have inactivating action for viruses are used. The tanks must be equipped with tightly closing corks (silicone, rubber or from other materials) and a protective cap (aluminum foil, thick paper). Capacities are opened immediately before the selection, removing the cork along with a sterile cap. During the selection, the cork and edge of the tank should not touch anything. It is not allowed to rinse the dishes. In the study of water from distribution networks, sampling from the crane is made after its preliminary sterilization of the burning and subsequent water descent of at least 10 minutes. With a fully open crane. In the selection of sample, water pressure can be reduced. The sample is selected directly from the crane without rubber hoses, water distribution grids and other nozzles. If the water flows constantly through sampling valve, the sampling is carried out without prior firing, without changing the water pressure and the existing design (in the presence of silicone or rubber hoses).

If the sample is taken after the disinfection of chemical reagents, then to neutralize the residual amount of chlorine-containing disinfectants into a container intended for sampling, it is brought to sterilization of sodium sterinity in the form of crystals or a concentrated solution at the rate of 10 mg per 500 ml of water. After filling, the container is closed with a sterile cork and cap. When sampling in the same point for various purposes, the first samples are taken for bacteriological studies.

The selected sample is marked and accompanied by the act of selection of water sampling indicating the place, date, selection time and other necessary information.

It is necessary to proceed to the study of water samples immediately after delivering samples into the laboratory.

Lecture 4. Water hygiene and water supply of urban and rural settlements. The quality of drinking water, methods for its improvement. Sanitary and hygienic study of drinking water.

1.	Water as a biosphere element.
2.	Water value for human life support.
3.	Properties of water (physical, chemical, biological, organoleptic), their influence on human health.
4.	Norms of water consumption in urban and rural settlements.
5.	Characteristics of water sources.
6.	Sources of pollution of water bodies.
7.	Self-cleaning of water bodies.
8.	Water supply systems.
9.	The quality of drinking water, methods for its improvement.
10.	Hygienic rationing of water quality.
11.	Methods of sanitary and hygienic study of drinking water.

sources of water supply "

Task Student:

1. Familiarize yourself with the regulatory documents in water hygiene and laboratory water analysis methods.

2. Having obtained a test of water, write down its passport details.

3. Swipe organoleptic and physico-chemical studies of drinking water quality and compare the obtained data with regulatory quantities.

4. Make a conclusion about the quality of drinking water and the conditions for using water sources based on the results of water analysis and examination of the water source.

5. Decide the situational task to assess the quality of drinking water and the choice of water source.

Work technique:

Determination of organoleptic properties of water

Water smell indicates the presence of polluting chemicals and water saturation with gases. The smell is determined at a temperature of 20 0 s and 60 0 C. The flask with a capacity of 150-200 ml is filled with water by 2/3 of the volume. The covering of its watch glass, intensively shaken and then, quickly opening, determine the smell of water. The smell is characterized as "chlorine", "earthy", "grinding", "marsh", "oil", "pharmacy", "uncertain" and t .. Quantitatively smell is estimated on a five-point scale (Table 34.).

Table 34. Smell intensity scale and drinking water taste

Smell	Description of the intensity of the smell	Point
Nic	Smell or taste is not felt
Very weak	Feels only an experienced analyst when heating water to 60 0 s
Weak	Feels, if you pay attention to it, and when heating water to 60 0 s
Perceptible	Feels without heating and significantly noticeable when water heated to 60 0 s
Distinct	Attracts attention and makes water unpleasant to drink without heating
Very strong	Sharp and unpleasant, water unsuitable for drinking

With a centralized water supply system, the smell of drinking water is allowed to drink no more than 2 points at 20 ° C and 60 0 s and ≤ 2-3-points - with a non-centralized (local) water supply system.

Taste of water Determined only in confidence that it is safe. The oral cavity is rinsed with 10 ml of the water under study and, without swallowing it, determine the taste ("salty", "bitter", "sour", "sweet") and a taste ("fish", "metallic", "uncertain", etc. .). The intensity of the taste is estimated on the same scale.

Water transparencydepends on the content of suspended substances. Transparency is determined by the height of the waters, through which you can read the text printed with standard font of Sellen. The investigated water is shaking and poured to the top to a special glass cylinder with a flat bottom and outlet tap at the bottom, on which a rubber tip with a clip will be. Place a cylinder with water over the font is stolen at a distance of 4 cm from the bottom of the cylinder and try to read the text through the thickness of the water pole in the cylinder. If the font does not succeed, then with the help of the clamp on the rubber tip of the cylinder, the water is gradually drained into a blank vessel and the height of the water column in the cylinder is noted, at which the letter of the font is distinguishable. Drinking water should have no transparency of at least 30 cm.

The degree of water transparency can also be characterized by its return value - turbidity. Quantitative turbidity is determined using a special device - a muder, in which the water under study must be compared with a reference solution prepared from the info-free land or kaolin on distilled water. The turbidity of water is expressed in milligrams of a suspended substance on 1 liter of water. The turbidity of 1.5 mg / l coaline is equal to transparency in 30 cm, with transparency of 15 cm turbidity is 3 mg / l.

Color water due to the presence of dissolved substances dissolved in water.

The color of water is determined by qualitatively by comparing the color of the filtered water (100 ml) from the color of the equal volume of distilled water. Cylinders with samples are considered over a white sheet of paper, characterizing the water under study as "colorless", "weakly yellow", "drowned", etc.

Quantitative determination of the chroma is carried out by comparing the intensity of the color of the test water with a standard scale, which allows it to express it in conventional units - degrees of chroma.

Color scales represents a set of 100 ml cylinders filled with a reference solution of various dilutions. A platinum-cobalt or chromium-cobalt scale with maximum color 500 0 is used as a reference solution. For the preparation of the scale, a number of colorimetric cylinders with a capacity of 100 ml are taken and the basic solution and distilled water with 1 ml of chemically pure sulfuric acid are poured into them (Ud. Weight 1.84) per 1 liter of water in the quantities shown in Table. 35

For a quantitative color definition in degrees, 100 ml of water test pour into a colorimetric cylinder and compare its coloring from the color of the standards when considering from top to bottom through the water column on a white background. Determine the degree of chroma of the water under study by choosing a cylinder having an identical staining intensity.

Hygienic conclusion about the quality of the test sample is made on the basis of comparison with hygienic standards: the chromaticity of drinking water is allowed not more than 20 0 (no more than 35 0) are allowed with the centralized water supply system and not more than 30 0 - with a non-centralized water supply system. Determining the color of water is possible using a photoelectrocolorimeter.

Table 35. Scale for determining the color of water

Sanitary and hygienic studies are a combination of methods that are used in hygiene to study the composition of air, water, and other objects. external environment. With the help of these studies, the influence of the external environmental factors on the human body is also being studied. Sanitary and hygienic studies allow to develop preventive measures aimed at protecting health and improving the living conditions of the population, as well as establish hygienic standards.

The simplest method of sanitary and hygienic studies is sanitary and descriptive. However, it does not give a complete presentation of the object being studied. Chemical, radiochemical and radiometric methods make it possible to determine the substances harmful to humans in various objects of the external environment. To establish such parameter hygiene, as temperature, humidity, movement and air pressure, noise, vibration, integral flow of radiant energy, air ionization, thermal conductivity of various materials, surface illumination, food caloric content, etc., physical research methods are widely used.

When evaluating food, drinking water is great importance to organoleptic research methods (see tasting).

Of great importance in sanitary and hygienic studies has a bacteriological study (see) drinking water and food products, as well as soils, household goods, clothing and equipment in enterprises food Industry. Bacteriological studies are widely used when examining the staff of the food industry and catering network for the carriage of pathogenic bacteria. Samples for bacteriological analysis should be selected in compliance with the rules for sterility (see).

Helmintological research methods (see) are used in sanitary and hygienic examination of water, soil, vegetables, as well as when controlling meat on and finnind. With sanitary control of catering enterprises, it is important to check on personal sanitary books, whether they were not found among workers with helminths, and if they were found, whether the treatment was carried out if the control analysis was made after treatment.

From biological methods in a sanitary and hygienic study, a biological method is used to determine the toxicity of harmful impurities, presence and other harmful substances.

Statistical methods are applied in sanitary and hygienic studies when studying the effects of external environmental factors on public health.

To determine the influence of various factors of the external environment on the function and physiological reactions of the human body and animals, physiological and biochemical research methods are widely used. These methods are also used to substantiate the maximum permissible concentrations of harmful substances in atmospheric air, water of water bodies, air of industrial premises, food products. In addition, biochemical methods are used in the definitions of biological usefulness of food and finished dishes.