Maximum concentrations of phosphorus in drinking water. MPC in water
IN Russian Federation The quality of drinking water must meet certain requirements established by SanPiN 2.1.4.10749-01 “Drinking water”. In the European Union (EU), the standards are determined by the Directive “On the quality of drinking water intended for human consumption” 98/83/EC. The World Health Organization (WHO) sets water quality requirements in the 1992 Guidelines for Drinking Water Quality. There are also regulations from the Protection Agency environment USA (U.S. EPA). The standards contain minor differences in various indicators, but only water of the corresponding chemical composition ensures human health. The presence of inorganic, organic, biological contaminants, as well as increased content non-toxic salts in quantities exceeding those specified in the presented requirements leads to the development various diseases.
Basic requirements for drinking water are that it must have favorable organoleptic characteristics, be harmless in its chemical composition and safe in epidemiological and radiation terms. Before supplying water to distribution networks, at water intake points, external and internal water supply networks, the quality of drinking water must comply with hygienic standards.
Table 1. Requirements for drinking water quality
| Indicators | Units of measurement | Maximum permissible concentrations (MPC), no more | Harmfulness indicator | Hazard class | WHO | U.S. EPA | EU |
| pH value | pH | 6-9 | - | - | 6,5-8,5 | 6,5-8,5 | |
| Total mineralization (dry residue) | mg/l | 1000 (1500) | - | - | 1000 | 500 | 1500 |
| General hardness | mEq/l | 7,0 (10) | - | - | - | - | 1,2 |
| Oxidability permanganate | mg/l | 5,0 | - | - | - | - | 5,0 |
| Petroleum products, total | mg/l | 0,1 | - | - | - | - | - |
| Surfactants (surfactants), anionic | mg/l | 0,5 | - | - | - | - | - |
| Phenolic index | mg/l | 0,25 | - | - | - | - | - |
| Alkalinity | mgHCO3-/l | - | - | - | - | - | 30 |
| Phenolic index | mg/l | 0,25 | - | - | - | - | - |
| Inorganic substances | |||||||
| Aluminum (Al 3+) | mg/l | 0,5 | With. -T. | 2 | 0,2 | 0,2 | 0,2 |
| Ammonium nitrogen | mg/l | 2,0 | With. -T. | 3 | 1,5 | - | 0,5 |
| Asbestos | Mill.fibers/l | - | - | - | - | 7,0 | - |
| Barium (Ba2+) | mg/l | 0,1 | -"- | 2 | 0,7 | 2,0 | 0,1 |
| Beryllium (Be2+) | mg/l | 0,0002 | - | 1 | - | 0,004 | - |
| Boron (B, total) | mg/l | 0,5 | - | 2 | 0,3 | - | 1,0 |
| Vanadium (V) | mg/l | 0,1 | With. -T. | 3 | 0,1 | - | - |
| Bismuth (Bi) | mg/l | 0,1 | With. -T. | 2 | 0,1 | - | - |
| Iron (Fe, total) | mg/l | 0,3 (1,0) | org. | 3 | 0,3 | 0,3 | 0,2 |
| Cadmium (Cd, total) | mg/l | 0,001 | With. -T. | 2 | 0,003 | 0,005 | 0,005 |
| Potassium (K+) | mg/l | - | - | - | - | - | 12,0 |
| Calcium (Ca +2) | mg/l | - | - | - | - | - | 100,0 |
| Cobalt (Co) | mg/l | 0,1 | With. -T. | 2 | - | - | - |
| Silicon (Si) | mg/l | 10,0 | With. -T. | 2 | - | - | - |
| Magnesium (Mg +2) | mg/l | - | With. -T. | - | - | - | 50,0 |
| Manganese (Mn, total) | mg/l | 0,1 (0,5) | org. | 3 | 0,5 (0,1) | 0,05 | 0,05 |
| Copper (Cu, total) | mg/l | 1,0 | -"- | 3 | 2,0 (1,0) | 1,0-1,3 | 2,0 |
| Molybdenum (Mo, total) | mg/l | 0,25 | With. -T. | 2 | 0,07 | - | - |
| Arsenic (As, total) | mg/l | 0,05 | With. -T. | 2 | 0,01 | 0,05 | 0,01 |
| Nickel (Ni, total) | mg/l | 0,1 | With. -T. | 3 | - | - | - |
| Nitrates (by NO 3 -) | mg/l | 45 | With. -T. | 3 | 50,0 | 44,0 | 50,0 |
| Nitrites (by NO 2 -) | mg/l | 3,0 | - | 2 | 3,0 | 3,5 | 0,5 |
| Mercury (Hg, total) | mg/l | 0,0005 | With. -T. | 1 | 0,001 | 0,002 | 0,001 |
| Lead (Pb, total) | mg/l | 0,03 | -"- | 2 | 0,01 | 0,015 | 0,01 |
| Selenium (Se, total) | mg/l | 0,01 | - | 2 | 0,01 | 0,05 | 0,01 |
| Silver (Ag+) | mg/l | 0,05 | - | 2 | - | 0,1 | 0,01 |
| Hydrogen sulfide (H 2 S) | mg/l | 0,03 | org. | 4 | 0,05 | - | - |
| Strontium (Sg 2+) | mg/l | 7,0 | -"- | 2 | - | - | - |
| Sulfates (S0 4 2-) | mg/l | 500 | org. | 4 | 250,0 | 250,0 | 250,0 |
| Fluorides F - (for climatic regions) | |||||||
| I and II | mg/l | 1,5 | With. -T. | 2 | 1,5 | 2,0-4,0 | 1,5 |
| III | mg/l | 1,2 | -"- | 2 | |||
| Chlorides (Cl -) | mg/l | 350 | org. | 4 | 250,0 | 250,0 | 250,0 |
| Chromium (Cr 3+) | mg/l | 0,5 | With. -T. | 3 | - | 0.1 (total) | - |
| Chromium (Cr 6+) | mg/l | 0,05 | With. -T. | 3 | 0,05 | 0,05 | |
| Cyanides (CN -) | mg/l | 0,035 | -"- | 2 | 0,07 | 0,2 | 0,05 |
| Zinc (Zn 2+) | mg/l | 5,0 | org. | 3 | 3,0 | 5,0 | 5,0 |
social-t. – sanitary-toxicological; org. –organoleptic.
Significant amounts of sulfates are dispersed on the surface of Baikal and river basins flowing into Baikal by air emissions from industrial enterprises, thermal power plants, and boiler houses. In local areas along the coast, sulfate ion can be an informative indicator of anthropogenic pollution brought by rivers, groundwater and direct discharge into Baikal of insufficiently treated industrial (using sulfuric acid and its derivatives), agricultural and domestic wastewater (from waste organic matter containing sulfur).
Sanitary standard sulfate content in drinking water (maximum permissible concentrations) - no more than 500 mg/dm 3 according to SanPiN 2.1.4.1074-01 (M.: Goskomsanepidnadzor, 2001), MPC for fishery production - 100 mg/dm 3, MPC for Baikal waters - 10 mg/dm3, background values for Baikal - 5.5 mg/dm3. The degree of harmfulness of sulfates according to SanPiN is hazard class 4 (moderately hazardous according to organoleptic characteristics).
Maximum permissible concentrations of chlorides in drinking water according to SanPiN 2.1.4.1074-01 - no more than 350 mg/dm 3, MAC for fisheries production - 300 mg/dm 3, MAC for Baikal waters - 30 mg/dm 3, background values for Baikal - 0.4 mg/dm3. The degree of harmfulness of chlorides according to SanPiN is hazard class 4 (moderately hazardous according to organoleptic characteristics).
IN natural waters occurs in very small concentrations, often inaccessible to existing mass analysis methods (hundredths of mg/dm 3). An increase in the concentration of ammonium and ammonia ions can be observed during the autumn-winter periods of dying off aquatic organisms, especially in areas where they accumulate. A decrease in the concentration of these substances occurs in spring and summer as a result of their intensive absorption by plants during photosynthesis. A progressive increase in the concentration of ammonium ion in water indicates a deterioration in the sanitary condition of the reservoir.
The norm of ammonia content in water (maximum permissible concentrations) is no more than 2 mg/dm 3 for nitrogen (maximum permissible concentrations and estimated safe exposure levels harmful substances in the water of water bodies for domestic, drinking and cultural water use, Ministry of Health, 1983), MPC of ammonium ion for fishery production - 0.5 mg/dm 3, MPC for Baikal waters - 0.04 mg/dm 3, background values for Baikal - 0.02 mg/dm3.
Nitrates according to SanPiN 2.1.4.1074-01 classification belong to the 3rd hazard class (organoleptically dangerous).
The sanitary standard for the content of nitrates in drinking water (MPC) is no more than 45 mg/dm 3 according to SanPiN 2.1.4.1074-01, MAC for Baikal waters is 5 mg/dm 3, background values for Baikal are 0.1 mg/dm 3.
Phosphate ion, like sulfate ion, is an informative indicator of anthropogenic pollution, which is facilitated by wide application phosphorus fertilizers (superphosphate, etc.) and polyphosphates (as detergents). Phosphorus compounds enter the reservoir during biological wastewater treatment.
According to SanPiN 2.1.4.1074-01, phosphates are classified as hazard class 3 (organoleptically hazardous). The sanitary standard for the content of phosphates in drinking water (MPC) is no more than 3.5 mg/dm 3 , MAC for fisheries production is 0.2 mg/dm 3 , MAC for Baikal waters is 0.04 mg/dm 3 , background values for Baikal - 0.015 mg/dm3.
Note: MPCs for Baikal waters are given according to the document "Norms for permissible impacts on the ecological system of Lake Baikal (for the period 1987-1995). Basic requirements", which is currently legal force does not have.
This document was approved by the President of the USSR Academy of Sciences, Academician G.I. Marchuk, Minister of Land Reclamation and Water Resources of the USSR N.F. Vasiliev, Minister of Health of the USSR, Academician E.I. Chazov, Chairman State Committee USSR on hydrometeorology and environmental control, corresponding member. USSR Academy of Sciences Yu.A.Izrael, USSR Minister of Fisheries N.I.Kotlyar.
PECV is the maximum permissible concentration of a substance in the water of a reservoir for domestic, drinking and cultural water use, mg/l. This concentration should not have a direct or indirect effect on the human body throughout life, as well as on the health of subsequent generations, and should not worsen the hygienic conditions of water use. PEEP.r. - Maximum permissible concentration of a substance in the water of a reservoir used for fishing purposes, mg/l.
Assessment of the quality of aquatic ecosystems is based on regulatory and policy documents using direct hydrogeochemical assessments. In table 2.4 shows the criteria for assessing chemical pollution as an example surface waters.
For water, maximum permissible concentrations are set at more than 960 chemical compounds, which are combined into three groups according to the following limiting hazard indicators (LHI): sanitary-toxicological (s.-t.); general sanitary (general); organoleptic (org.).
Maximum concentration limits for some harmful substances in aquatic environment are presented in table. 2.1.4.
The highest demands are placed on drinking water. State standard for water used for drinking and food industry(SanPiN 2.1.4.1074-01), determines the organoleptic indicators of water that are favorable for humans: taste, smell, color, transparency, as well as the harmlessness of its chemical composition and epidemiological safety.
Table 2.1.4
Maximum permissible concentrations of harmful substances in water bodies of domestic and drinking water and
cultural and domestic water use, mg/l
(GN 2.1.5.689-98)
| Substances | LPV | maximum permissible concentration |
| 1 | 2 | 3 |
| />Boron | S.-t. | 0,5 |
| Bromine | S.-t. | 0,2 |
| Bismuth | S.-t. | 0,1 |
| Hexachlorobenzene | S.-t. | 0,05 |
| Dimethylamine | S.-t. | 0,1 |
| Difluorodichloromethane (freon) | S.-t. | 10 |
| Diethyl ether | Org. | 0,3 |
| Iron | Org. | 0,3 |
| Isoprene | Org. | 0,005 |
| Cadmium | S.-t. | 0,001 |
| Karbofos | Org. | 0,05 |
| Kerosene: | | |
| Oxidized | Org. | 0,01 |
| Lighting (GOST 4753-68) | Org. | 0,05 |
| Technical | Org. | 0,001 |
| Acid: | | |
| Benzoinaya | General | 0,6 |
| Diphenylacetic | General | 0,5 |
| Oily | General | 0,7 |
| Ant | General | 3,5 |
| Vinegar | General | 1,2 |
| Synthetic fatty acids | General | 0,1 |
| S5-S20 | | |
| Manganese | Org. | 0,1 |
| Copper | Org. | 1 |
| Methanol | St. | 3 |
| Molybdenum | St. | 0,25 |
| Urea | General | 1 |
| Naphthalene | Org. | 0,01 |
| Oil: | | |
| Polysulphurous | Org. | 0,1 |
| Durable | Org. | 0,3 |
| Nitrates by: | | |
| NO3- | St. | 45 |
| NO2- | St. | 3,3 |
| Polyethyleneamine | St. | 0,1 |
| Thiocyanates | St. | 0,1 |
| Mercury | St. | 0,0005 |
| Lead | St. | 0,03 |
| Carbon disulfide | Org. | 1 |
| Turpentine | Org. | 0,2 |
| Sulfides | General | Absence |
| Tetraethyl lead | St. | Absence |
| Tributyl phosphate | General | 0,01 |
Drinking water at any time of the year should not contain less than 4 g/m of oxygen, and the presence of mineral impurities in it (mg/l) should not exceed: sulfates (SO4 -) - 500; chlorides (Cl -) - 350; iron (Fe2+ + Fe3+) - 0.3; manganese (Mn2+) - 0.1; copper (Cu2+) - 1.0; zinc (Zn2+) - 5.0; aluminum (Al) - 0.5; metaphosphates (PO3 ") - 3.5; phosphates (PO4
3") - 3.5; dry residue - 1000. Thus, water is suitable for drinking if its total mineralization does not exceed 1000 mg/l. Very low mineralization of water (below 1000 mg/l) also worsens its taste, and water , generally devoid of salts (distilled), is harmful to health, since its use disrupts digestion and the activity of the glands internal secretion. Sometimes, in agreement with the sanitary and epidemiological service authorities, a dry residue content of up to 1500 mg/l is allowed.
Indicators characterizing the pollution of reservoirs and drinking water with substances classified as hazard classes 3 and 4, as well as physical and chemical properties and organoleptic characteristics of water are considered additional. They are used to confirm the intensity of anthropogenic pollution of water sources, established according to priority indicators.
The application of various criteria for assessing water quality should be based on the superiority of the requirements of the water use whose criteria are more stringent. For example, if a water body simultaneously serves for drinking and fishery purposes, then more stringent requirements (environmental and fishery) may be imposed on the assessment of water quality.
PCP-10 (chemical pollution indicator). This indicator is especially important for areas where chemical pollution is observed for several substances at once, each of which exceeds the maximum permissible concentration many times. It is calculated only when identifying zones of environmental emergency and zones of environmental disaster.
The calculation is carried out for ten compounds that maximally exceed the maximum permissible concentration, according to the formula:
PKhZ-10 = S1/PDK1 + S2/PDK2 + S3/PDK3 + ...S10/PDK10,
where Cu C2, C3 ... Cu is concentration chemicals in water: MPC - fisheries.
When determining PCP-10 for chemicals for which there is no relatively satisfactory level of water pollution, the C/MPC ratio is conventionally assumed to be equal to 1.
To establish PCP-10, it is recommended to analyze water according to the maximum possible number of indicators.
Additional indicators include generally accepted physicochemical and biological characteristics giving general idea about the composition and quality of water. These indicators are used to further characterize the processes occurring in water bodies. In addition, in additional characteristics include indicators that take into account the ability of pollutants to accumulate in bottom sediments and aquatic organisms.
The bottom accumulation coefficient KDA is calculated using the formula:
KDA = Sd.o./St,
where Sd. O. and St - concentration of pollutants in bottom sediments and water, respectively.
Accumulation coefficient in hydrobionts:
Кн = Сг/Св,
where Cg is the concentration of pollutants in hydrobionts.
Critical concentrations of chemical substances (CC) are determined according to the method for determining critical concentrations of pollutants developed by the State Committee for Hydrometeorology in 1983.
The average CC values of some pollutants are, mg/l: copper - 0.001 ...0.003; cadmium - 0.008... 0.020; zinc - 0.05...0.10; PCB - 0.005; benz(a)pyrene - 0.005.
When assessing the state of aquatic ecosystems, fairly reliable indicators are the characteristics of the state and development of all ecological groups of the aquatic community.
When identifying the zones under consideration, indicators for bacterio-, phyto-, and zooplankton, as well as ichthyofauna, are used. In addition, to determine the degree of toxicity of waters, an integral indicator is used - biotesting (on lower crustaceans). At the same time, the corresponding toxicity water mass should be observed in all main phases of the hydrological cycle.
The main indicators for phyto- and zooplankton, as well as zoobenthos, were adopted on the basis of data from regional hydrobiological control services, characterizing the degree of environmental degradation of freshwater ecosystems.
The parameters of the indicators proposed for identifying zones in a given territory should be formed on materials of sufficiently long observations (at least three years).
It should be borne in mind that the indicator values of species may differ in different climatic zones.
When assessing the state of aquatic ecosystems, indicators on ichthyofauna are important, especially for unique, specially protected water bodies and reservoirs of the first and highest fishery categories.
BOD - biological oxygen demand - the amount of oxygen used in biochemical processes oxidation of organic substances (excluding nitrification processes) for certain time sample incubation (2, 5, 20, 120 days), mg O2/l of water (BODp - for 20 days, BOD5 - for 5 days).
The oxidative process under these conditions is carried out by microorganisms that use organic components as food. The BOD method is as follows. After two hours of settling, the wastewater under study is diluted clean water, taken in such a quantity that the oxygen contained in it is sufficient to completely oxidize all organic substances in the wastewater. Having determined the content of dissolved oxygen in the resulting mixture, it is left in a closed flask for 2, 3, 5, 10, 15 days, determining the oxygen content after each of the listed periods of time (incubation period). A decrease in the amount of oxygen in water shows how much of it is spent during this time on the oxidation of organic substances in wastewater. This amount, referred to 1 liter of wastewater, is an indicator of the biochemical oxygen consumption of wastewater for a given period of time (BOD2, BPKz, BPK5, BPKyu, BPK15).
It should be noted that biochemical oxygen consumption does not include its consumption for nitrification. Therefore, complete BOD should be carried out before the start of nitrification, which usually begins after 15-20 days. BOD of wastewater is calculated using the formula:
BOD = [(a1 ~ b1) ~ (a2 ~ b2)] X 1000
V'
where ai is the oxygen concentration in the sample prepared for determination at the beginning of incubation (on “day zero”), mg/l; a2 is the oxygen concentration in the diluting water at the beginning of incubation, mg/l; b1 - oxygen concentration in the sample at the end of incubation, mg/l; b2 - oxygen concentration in dilution water at the end of incubation, mg/l; V is the volume of wastewater contained in 1 liter of sample after all dilutions made, ml.
COD is the chemical demand for oxygen, determined by the bichromate method, i.e. the amount of oxygen equivalent to the amount of consumed oxidizing agent necessary for the oxidation of all reducing agents contained in water, mg O2/l of water.
Chemical oxygen consumption, expressed as the number of milligrams of oxygen per 1 liter of wastewater, is calculated using the formula:
HPc - 8(a - b)x N1000
V'
where a is the volume of Mohr's salt solution consumed for titration in a blank experiment, ml; b is the volume of the same solution used to titrate the sample, ml; N is the normality of the titrated solution of Mohr's salt; V is the volume of analyzed wastewater, ml; 8 - oxygen equivalent.
The BODp/COD ratio is used to judge the effectiveness of biochemical oxidation of substances.
