Method of determining pollution water body using hydrobionts
FIELD: ecological monitoring of water bodies.
SUBSTANCE: bio-testing is done directly in the water body using hydrobionts, not adapted to the water medium under test. The hydrobionts are put in a water permeable container.
EFFECT: consideration of the possibility of determining the quality of water in water bodies during testing and obtaining results which reflect the real ecological condition.
The invention "method for determining the contamination of a water body using hydrobionts" relates to the field of environmental monitoring of water objects.
The existing system of control of water pollution, based on the determination of analytical methods maximum permissible concentrations of individual substances and health indicators, does not ensure the preservation of the environmental health of water bodies due to several factors: lack of quantitative analytical methods for the determination of all the toxic compounds contained in the composition of the effluent; heterogeneous nature of the interaction of individual components in the mixture; secondarily formed by the connections that can be more toxic than the analyzed original substance. In addition, the identification of a large number of separate indicators not addressed the issue of the degree of risk to aquatic biocenoses of pollutants in water bodies with wastewater.
All these circumstances have necessitated the development of integrated control methods of natural and waste water, allowing to evaluate the possible danger of those or other sources of contamination to aquatic flora and fauna. The most effective means to meet these objectives, is the biota of the aims, with the help of which you can install the toxic effects of contaminated water on biological objects.
Biotesting - determination of the degree of survival of laboratory organisms in a given test environment.
Our country has developed more than 40 bioassay techniques and their modifications. Detailed description of the main of them is given in the book "Methods of biotesting of water" . Developed Methodological guidance on biotesting RD 118-02-90, which encompasses all the stages of Toxicological control of wastewater and water quality control ponds and watercourses (natural waters) methods of biotesting using as test objects crustaceans, algae and fish . All of these works biotesting is proposed to carry out in laboratory conditions with the removal of water from the water bodies and the use of animals placed in vessels of the type aquariums.
Most effective for assessing water quality control sections is a classic Biotest based on the registration of survival and fecundity of Daphnia, which are sensitive to a wide range of toxic substances of different classes of chemical compounds.
A prototype of this invention is the article "a Method for biological testing using Daphnia" .
Disadvantages laboratory bi is testing due to the impossibility of creating conditions identical to natural. The percentage errors are significant, especially if the test is subjected to the pollution of natural water. Than more toxic aqueous medium, the smaller the percentage error. I.e. the classical test is suitable only for wastewater.
Tests in laboratory conditions leads to errors due to:
1. Changes in water quality over time.
2. Aquarium cannot take account of possible changes in water quality after sampling due to new portions of pollutants.
3. A species can adapt to the conditions of the test.
To avoid error due to adaptation of aquatic organisms to contaminants and a large amount of time between sampling and testing are encouraged to biotesting directly into a water body, i.e. a method of "reverse" biotesting, when the animals are placed in the test environment, without transferring water samples in the laboratory. When transferring water samples in the laboratory, it is removed from the natural complex, and deprived of all possible factors which influence the process of transformation of contaminants in nature. Device for biotesting in the natural aquatic environment in the literature are not given.
For biological testing device in use, different is seesa fact, what is the purpose of biotesting of water bodies in conditions as close to natural, it consists of a container that represents the camera, made of permeable material (mill gas No. 72-76), mounted on a rigid frame made of corrosion-resistant wire can be installed to the desired depth by means of a cord, cargo and float.
The device must meet the following requirements:
1. To have sufficient spatial volume for the existence of the test organisms.
2. The permeability of the walls of algae, bacteria and dissolved nutrients.
3. Ease of manufacture.
4. Corrosion resistance.
5. The availability of materials.
As test objects can be used:
1. Classical laboratory cultures of Daphnia maqna Sfraus, Daphnia pulex De Geer - grown in accordance with the instructions RD - 118 .
2. Regional dominant, preferably related to classical laboratory species.
3. Dominant and mass species from among the inhabitants of the tested reservoir.
In the case of test objects under # 2 and # 3 reservation "overexposure" of individuals in laboratory conditions (in aquariums) to obtain authentic to test the water culture. The optimal effect is confirmed when using the years of second generation individuals, regional Cladocera Daphnia cucbafa Sars, Daphnia louqispiuc Meiller, Cerioclaphuia pulcyella Sars, Scapholeberis mucrohafa Muller and others, bred in laboratory conditions.
When testing a certain number of laboratory Daphnia (for example, 13 pieces) are placed in the container and fall into the water at a certain depth. Conducted periodic visual observation of the condition of organisms - the number of dead individuals, locomotor activity, the emergence of the offspring.
Water quality assessment is performed on the reactions of the test object on the survival, reproduction and immobilization (loss of motor activity)(table 1).
Quality assessment of water on the reactions of the test object
|Grade||Pollution degree||The saprobity index||The response of test organisms in the container (No. 1, 2, 3 - the 7 day)|
|1||Net||1,0||Immobilization of up to 2%. Parthenogenesis.|
|2||Moderately clean||1,0-1,5||Immobilization of up to 10-20%. Parthenogenesis. Partial sexual reproduction.|
|3||Moderately polluted||1.5 to 2.5||Immobilization of up to 70-80%. Sexual reproduced the interview. Immobilization evenly stretched.|
|4||Contaminated||2,5-3,5||Death - 2-3 days|
|5||Dirty||3,5-4,0||Death - 1 day|
|6||Very dirty||4,0||Lethal - 15 min - 1 hour|
The proposed method was tested in field conditions during the examination of waters of the rivers Volga, Kama and Mesh. Results on some of the points presented in table 2.
The results of biological testing of water bodies
|No. station||Station name||Survival,%||Water quality assessment|
|1 hour||1 day||2 days||3 days||4 days||6 days||Grade||Pollution degree||The saprobity index|
|1||Mouth rmesa, (direction) depth 4 m||100||0||5||dirty||3,5-4,0|
|3||Merging currents rmesa and Kama, depth 6 m||100||77||62||46||31||31+||3||moderately polluted||1.5 to 2.5|
|4||Old channel RCAM about Islands arrow Drilling, depth 4 m||0||6||very dirty||4,0|
|5||Channel Volga river near Kurilovo, depth 13 m||100||100||46||31||15||15+||3||moderately polluted||1.5 to 2.5|
|6||Shallow water along the section of Atabaev-Kurilovo, depth 3 m||100||100||100||100||100+||100+||1||net||1,0|
|7||3 km from No. 6, depth 3.5 m||100||100||100||100||100||100+||1||net||1,0|
|8||Old channel RCAM about Laishevo, depth 7 m||0||6||very dirty||4,0|
|9||The confluence of the Volga and the Kama, depth 10 m||100||38||38||23||8||0||4||contaminated||2,5-3,5|
|+the appearance of the offspring|
According to the results of biological testing has determined particularly contaminated zone in paragraphs 1, 4, 8.
In paragraph 8 of hydrochemical indicators of exceedance of MPC is not detected. But in the study of bottom soil defined γ-background isotope cesium-137, which reaches 51,8 Bq/kg in Addition, the fish Kamsko-Ustinsky ples have a high content of zinc and copper, and a very high amount of Nickel to 90.4 mg/kg, 180,8 times the MAC.
The proposed method of determining the contamination of water bodies with the use of aquatic organisms has several advantages compared with prototype:
1. The results obtained reflect the real environmental situation in the inspection zone, associated not only with the presence of certain pollutants, but with environmental factors (temperature, nutrient availability, oxygen content, pH and the like).
2. Take into account the possibility of changes in water quality in a water body in the process of testing.
3. Reveals the impact of unexpected factors, such as radioactivity.
4. The simplicity of the experiment.
1. Methods of biotesting of water. Edited by Krainykovo A.N. Branch of the Institute of chem. physics, USSR Academy of Sciences, Chernogolovka, 1988, 122 S.
2. Methodological guidance on biotesting of water. RD 118-02-90 State. the Committee of the USSR for nature protection, Moscow, 1990, 71 S.
3. Isakov E.F., Kolosova L.V. Method of biotesting using dafny//Sat. Methods of biotesting. Branch of the Institute of chem. physics, USSR Academy of Sciences, Chernogolovka, 1988, p.50-57.
The method for determining the contamination of the water body with the use of aquatic organisms for their survival, fecundity and offspring, characterized in that conduct testing of water directly into a water body using unadapted to test the water hydrobionts, placed in a permeable container.
FIELD: physical and chemical analysis.
SUBSTANCE: method involves experimental determination of the composition of an equilibrium liquid phase of an initial component mixture having an optimum composition, measurement of any easily measurable physical property of the liquid phase after equilibrium is reached in a known initial mixture of components located strictly at sections of the composition triangle; the composition property diagram is plotted, a system of intercrossing lines is obtained, with the number of lines equal to the number of fields dissected by the selected section, the functional line intersection points determine borders of fields with different phase states. Solid phases are identified by the intersection points of limit nodes entering the same solid phase, defined by the coordinates of experimentally determined compositions of nonvariant liquid phases, borders in delimiting systems, and apexes of nonvariant areas of isohydric sections of a system without isolation, separation, or additional identification of bottom phases; the nonvariant area border orientation relative to the sides of the salt (anhydrous) concentration figure of the section of the system under research determines the type of phase interaction in it, while the parallelism of these borders to the sides of the concentration figure of the isohydric section is a sign of crystallisation from the nonvariant solution of anhydrous salt components, which compose this concentration figure, and the absence of parallelism of the borders of the nonvariant area to the sides of the concentration figure of the isohydric section is a sign of formation of a new solid phase or crystallohydrates in the system. If a new solid phase is found, the initial system is triangulated accordingly, all compositions of nonvariant solutions saturated also with this solid phase, and coordinates of apexes of the corresponding nonvariant isohydric areas are determined experimentally, the obtained results are combined to determine the compositions of all equilibrium solid phases in order to confirm the phase interaction types in the subsystems obtained and prove the absence of any other solid phases without isolating them from the liquid phase.
EFFECT: simplification of and increased reliability and informativity of determination.
2 cl, 3 ex, 14 tbl, 4 dwg
FIELD: physical and chemical analysis.
SUBSTANCE: carried out by determining compositions of nonvariant solutions saturated with n-2 and n-1 salts, and calculating the component ratio using a straight-line equation, the coordinates of borders of nonvariant areas of isohydric sections in (n-1)- and apexes in n-component systems are determined experimentally without separating the equilibrium phases, and compositions of equilibrium solid phases are determined by identifying the intersection point of two limit nodes predetermined by the compositions of the corresponding nonvariant solutions and borders or apexes of novariant areas.
EFFECT: decrease in labour consumption and increase in determination reliability.
3 ex, 12 tbl, 6 dwg
FIELD: ecology; analytical chemistry.
SUBSTANCE: method includes sampling, concentration of volatile impurities, chromatographic analysis including the concentrate separation on a capillary column with a polar stationary liquid phase and flame-ionisation detection with holding at 60° C, temperature rise at a rate of 10° C/min to 120° C and holding at this temperature, isolation of toluene and 1,2,4-trimethylbenzene as reference compounds, determining proportion of their concentrations in the sample, and calculation of the time of petrol-to-water contact by the formula: x = (2.27 - y)/ 0.023 where x is the time of petrol-to-water contact, hours; y is Stoluene/S1,2,4 - TMB, Stoluene and S1,2,4 - TMB - concentrations of toluene and 1,2,4-trimethylbenzene in the sample corresponding to areas of the peaks in the chromatogram.
EFFECT: higher reliability of determination.
2 ex, 2 tbl
FIELD: invention refers to methods of investigation of water and may be used for analysis of content of organic pollutants in drinking and other waters.
SUBSTANCE: mode is based on interaction of tannin with organic pollutants containing in natural waters, with forming dissoluble in water quinoid structures giving sample of water dark color. For analysis they use 25% solution of tannin, reaction is conducted at temperature 80-90°C withfollowing measuring of optical density of sample at 440 nm.
EFFECT: increases sensitivity and also simplifies and accelerates analysis.
FIELD: invention refers to field of using vegetable objects for control over pollution of environment.
SUBSTANCE: it may find application in ecological monitoring and sanitary-toxicological control over water, soil and also in pharmacology at evaluation safety of biologically active substances. Mode is in complex estimation of cytogenetic, structural-metabolic and morphological-physiological violations observed in phytotests. Cytogenetic and structural-metabolic violations are found in bulbs of Allium cepa . At that increases of frequency of aberration of cells and changing of mitotic index serve as indicators of cytogenetic violations, increase of cells with three and more nucleouses in nucleus and changing of duration of maceration of rootlets of bulbs serve as indicators of structural-metabolic violations. Morphological violations are found in Phaseolus vulgaris. At that reduce of germinating ability of seeds, increase of frequency of morphosises and changes in green mass serve as indicator of morphological-physiological violations.
EFFECT: mode allows objectively forecast effects of aftereffects of factor on popularized level.
3 tbl, 1 ex
FIELD: analytical chemistry and ecology, in particular, method for determining micro-concentrations of antimony in water.
SUBSTANCE: method includes preparation of analyzed sample by concentrating analyzed solution, which contains antimony, to the state of solid residual, dissolution of dry residual in 3,5-4,0 M hydrochloric acid, placement of prepared sample in a solution which contains 30-40% of potassium iodide, 10-15% solution of ascorbic acid, aging of resulting mixture over 15-25 minutes and addition of metallic zinc, distillation of resulting product by letting it through absorbing solution of partially oxidized diphenyl carbazide until the color of absorbing solution stops changing, photometry of absorbing solution.
EFFECT: increased selectivity and sensitivity of analysis.
3 ex, 3 tbl, 1 dwg
FIELD: environmental monitoring.
SUBSTANCE: invention relates to the area of utilizing microbiological objects for checking environmental pollution and can find use in environmental monitoring and sanitary-toxicological inspection of water, soils as well as in pharmacology when estimating safety of biologically active substances. Method consists in registration of variability of nature of colony-formation of two yeast strains Sacharomyces cerevisae exhibiting different ploideness under different medium conditions. Haploid and diploid strains are used. Toxic effect is established from lethal characteristics and mutagenicity from rise in number of mutant forms of colonies. Thereafter, induction of heritable cellular lethality is determined and remote pathology is predicted from the number of morphoses and change in the sizes of colonies.
EFFECT: improved reliability of toxico-genetic estimation due to use of sensitive haploid strains, specific reactions of haploids and diploids when affected by weak doses of mutagens.
2 dwg, 1 tbl
FIELD: analytical methods in food industry and biotechnology.
SUBSTANCE: object of invention is to determine contents of cations, amines, anions of organic and inorganic acids in various media in food, alcoholic beverage and soft drink industries. Working electrolyte for electrophoretic determination of ions is composed of, mmole/L: histidine 25-35, 2-morpholinoethanesulfonic acid 100-140, a Crown ether 1.5-2.5, Triton X-100 0.02-0.50, and water - the rest.
EFFECT: enabled simultaneous determination of cations, amines, anions of organic and inorganic acids in various media.
FIELD: medicine; ecology; hygiene.
SUBSTANCE: method can be used for analysis and differentiation of degree of pureness of water on purpose of revealing of effect of water onto human health, as well as for checking pureness of water in laboratory tests. Tested sample of water in amount of 2-5 ml is placed into dish of chemiluminometer. Flash is measured and ozone is supplied to dish through waterproof light-protected capillary gas-duct at speed of up to 10 mcg ozone/sec. Intensity and dynamic changes in chemiluminescence are measured during 1 minute. Computer automatically processes result of measurements and it is presented in form of graph of changes in chemoluminescence. Maximal signal (peak meaning) is calculated and total number of flashes is calculated within 1 minute (light sum of pulses during 60 seconds).
EFFECT: high sensitivity of method; reduced lower limit of measurement range; reduced amount of water necessary for tests.
1 tbl, 2 dwg
FIELD: environmental protection; methods of biotesting of the water on heavy metals pollution.
SUBSTANCE: the invention is pertaining to the method of the analytical biotesting of water. For the biotesting -cultivate the plants of the duckweed small Lemna minor L. at the permanent daylight and the temperature mode and the composition of the growth mineral medium. The biotesting duration makes 7 days. The toxicity degree is estimated through the mean day gain of the growth share of the duckweed small and compute it by the formula: D =(B-A)/A·t, where A is the initial number of the small leaves of duckweeds in the probe; B - the final number of the small leaves; t - growth time (in days). The number of the small leaves is counted in the probes on 2-d, 5-th and 7-th day of the test. Availability of the pollutants determine by the complex of the morphological changes of the duckweed. In the capacity of the morphological changes of the duckweed use the specific changes of the color of the young and mature plants with the characteristic localization on the small leaves, conservation of the groups of the duckweeds small leaves or their decay - partial or complete, conservation or dropping of the roots. The method allows to increase the information value of the water biotesting system.
EFFECT: the invention ensures the increased information value of the water biotesting system.
FIELD: analytical methods in environmental monitoring.
SUBSTANCE: method comprises: sampling, acidifying samples with HCl/H2SO4 mixture, adding Ce(SO4)2 as oxidant and removing its excess with reducing agent NH2OH·HCl, adding rhodamine C as organic reagent, extracting resulting complex, separating organic phase from aqueous phase, and measuring optical density. Extraction is performed with carbon tetrachloride/methyl isobutyl ketone mixture at 5:1 volume ratio and extractant-to-sample volume ratio 1:1 under dynamic conditions by way of washing away complex with extractant. Content of antimony is judged of from difference of optical densities of extractant and mixture.
EFFECT: lowered measurement threshold to values comparable with allowable limits, increased reliability, reduced analysis time, and automated analytical procedure.
3 cl, 1 dwg, 3 tbl, 3 ex
FIELD: environmental monitoring.
SUBSTANCE: invention relates to hygiene and sanitary of freshwater reservoirs and is meant to be used for microbiological testing of condition of water source in an agricultural enterprise effluent zone, in particular in the effluent zone of poultry factories and pig-breeding farms. For this aim, water is sampled at least in two zones: in the effluent zone of agricultural enterprise and in the zone, where influence of agricultural enterprise effluent over different periods is excluded. Then, contents of ammonia compounds and enzymatic activities of urease-carbamidamidohydrolase in samples are measured. Obtained data are processed: contents of ammonia compounds and enzymatic activities in different samples are compared to each other and dynamic of changes in data in samples taken from different zones are compared.
EFFECT: enabled quick testing at high accuracy in estimations and minimized labor and means involved.
FIELD: toxicology, in particular determination of water flea sensibility to toxic effect of water-soluble chemicals.
SUBSTANCE: claimed method includes detection of water flea death time (min) caused by water-soluble chemicals, wherein concentration (C, mol/l) of chemical under consideration fluctuates according to logarithmic scale with interval of 0.1. Plot of Y versus X is made, wherein Y-axis represents average death time with scale of 1 point = 1 min; X-axis represents reverse concentration (1/C) of chemical under consideration; and scale is proportional to log increasing by 0.1. Water flea sensibility to toxic effect (tgα) is calculated according to equation: tgα = TL(min):1/KL = TL(min)xKl (I), wherein α is inclination of straight line to X-axis; TL(min) is death time (min) being determined according to point of hypothetical crosspoint of straight line with Y-axis; KL is lethality constant (mol/l) defined as chemical concentration wherein water flea death time is equal to 2TL(min).
EFFECT: Method allowing evaluation of toxic effect evolution dynamics and comparison of toxic effect of water-soluble chemicals in equal concentration ranges.
2 tbl, 1 ex, 1 dwg
FIELD: analytical methods in industrial sanitation.
SUBSTANCE: method envisages bringing solution to be analyzed into contact with potassium bichromate, sulfuric acid, and mercuric sulfate, ageing resulting mixture and allowing it to cool to ambient temperature, adding ferroin indicator, titration of excess of potassium bichromate with 0.125 n. Moor salt solution, and calculating chemical oxygen demand value from amount of Moor salt consumed in the titration. Method is characterized by that initial solution is preliminarily homogenized until diameter of suspended particles therein become as large as 0.03 mm, after which solution is allowed to stay for 4 min.
EFFECT: reduced determination inaccuracy.
FIELD: environmental protection.
SUBSTANCE: invention concerns estimation of environmental pollution using bioassay methods. In particular, method is accomplished through bioindication of controlled area using, as bioindicators, internals (muscles, kidneys, liver) of wild hoofed animals (elk, dear, wild boar). One determines content of heavy metals in these organs placed within an area, compares thus obtained data with maximum permissible concentrations of heavy metals in foods, and estimates heavy metal pollution level of the area from resulted difference. Existence of long-term pollution of a region is judged of from excess concentration of heavy metals in wild hoofed animal kidneys and existence of single release of mercury and lead from that in muscles and liver.
EFFECT: enabled multiple estimation of considerable areas at reduced effort.
2 cl, 3 tbl
FIELD: analytical methods in environmental protection and toxicology.
SUBSTANCE: subject of invention is drinking, natural, and waste water quality monitoring. Toxicity of aqueous medium is determined from variation in activity of animal brain plasma membrane Mg2+-ATPase activated by chlorine and/or bicarbonate ions. In one embodiment of invention, toxicity of aqueous medium is determined by mixing above plasma membranes with test aqueous medium adjusted to physiologic pH with phosphorus-free buffer followed by addition of solution containing Tris-ATP and magnesium ion source as well as chloride and/or bicarbonate ion(s) source, incubation until inorganic phosphorus is formed, and determination of toxicity from concentration of inorganic phosphorus. Brain plasma membranes used as indicator contain Mg2+-ATPase capable of being activated by chlorine and/or bicarbonate ions.
EFFECT: extended functional possibilities of method and use of reagent, increased sensitivity, and enabled determination of toxicity at lower concentration of various-type toxicants.
20 cl, 6 tbl
FIELD: environmental protection.
SUBSTANCE: invention concerns evaluation of pollution of areas with pesticides involving bioassay techniques. To that end, area under control is subjected to bioindication using wild hoofed animals (mainly elks, deer, wild boars) as bioindicators. Within specified period of time, animal internals are sampled, pesticide content therein is determined, and thus obtained results are compared with maximum permissible pesticide levels for food products. Comparison data are used to estimate quality of media.
EFFECT: increased representativeness of monitoring results, enabled evaluation of a vast region or local area or local agrocenosis at lower effort.
2 cl, 2 tbl
FIELD: chemistry, water quality control, method for quantitative estimation of organic substance properties in aqueous solutions.
SUBSTANCE: indicator plate is immersed in aqueous solution and according to alteration of aqueous solution composition chemical activity of organic substances in this solution is determined. In clamed method tree vessels are used. Two vessels contain aqueous solution to be tested and the third vessel contains control aqueous solution free from organic contamination. In aqueous solutions containing in the second and third vessels indicator plates are immersed, then aqueous solutions in all vessels are heated up to 95-105°C, held at this temperature for 55-65 min, cooled to 15-25°C, filtered though membrane filter with pore size of 0.46 mum, then iron content is measured in all vessels and chemical activity of organic substances in aqueous solutions is calculated according to equation ka=ΔFe/Fe1, wherein ΔFe = Fe2- Fe1- Fe3; Fe1 is iron content in the aqueous solution of the first vessel; Fe2 is iron content in the tested aqueous solution of the second vessel; and Fe3 is iron content in the aqueous solution of the third vessel.
EFFECT: simplified method with enhanced functionality.
3 ex, 4 tbl
FIELD: ecological engineering, particularly river monitoring with taking into consideration river pollution with sewage water within the limits of cities and other inhabited localities.
SUBSTANCE: method involves choosing river observation points relative single pollution source or pollution source array; aligning one observation point with single pollution cross-section or pollution cross-section array; taking water samples; conservation the samples and preparing thereof for following analysis; cultivating test-organism, namely one-celled green algae - Chlorella vulgaris, inside cultivator at temperature of 36±0.5°; measuring optical density thereof in red light; analyzing and estimating the measurement results. The observation points are transversal to river and set in front of single sewage pollution source or sewage pollution source array, in center of each source and behind them. All three observation points are located within the limits of a city or other inhabited locality. The optical density is measured before and after one-celled green algae cultivation in water samples. After measurement termination overall river water pollution index is determined.
EFFECT: possibility to compare overall river water pollution index obtained in particular observation point with that obtained from pollution source on river bank; extended functional capabilities and extended range of application.
5 cl, 4 tbl
SUBSTANCE: the present innovation deals with testing biological activity of water, preliminary treatment of water, division into control and tested portions, ionization of tested portion with silver ions, detection of the quantity of sprouted wheat grains per time unit pre-impregnated in both mentioned portions and calculation of relative alteration for the value of biological activity of water according to the following ratio: where d - relative alteration for the value of biological activity of water, %; Ntested - the quantity of sprouted grains per time unit in tested portion of water, pcs.; Ncontrol - the quantity of sprouted grains per time unit in control portion of water, pcs. Moreover, relative alteration for the value of biological activity of water being above 0 means increased biological activity of water, relative alteration for the value of biological activity of water being below 0 means its decrease, and equation of the mentioned relative alteration to 0 means intact nature of biological activity of water being different by the fact that pre-treatment of water should be carried out due to precipitation for 23-24 h at 23-26 C.
EFFECT: higher efficiency of investigation.