Heavy metals belong to priority pollutants, which are mandatory in all environments.

Term heavy metals,composing a wide group of pollutants, has recently received significant distribution. In various scientific and applied works, the authors interpret the meaning of this concept in different ways. In this connection, the number of elements attributable to a group of heavy metals varies widely.

As criteria, numerous characteristics are used: atomic weight, density, toxicity, prevalence in the natural environment, the degree of involvement in natural and man-made cycles. In some cases, elements belonging to fragile (for example, bismuth) or metalloids (for example, arsenic) fall under the determination of heavy metals.

In works on environmental pollution issues natural environment and environmental monitoring, to date, heavy metals include more than 40 metals of the periodic system D.I. Mendeleev with an atomic mass of over 50 atomic units: VA, CR, MN, FE, CO, Ni, Cu, Zn, Mo, SN, NG, RB, VE, etc.

In this case, the following conditions play an important role in categorizing heavy metals: their high toxicity for living organisms in relatively low concentrations, as well as the ability to bioaccumulation and biomagnification.

Almost all metals falling under this definition (with the exception of lead, mercury, cadmium and bismuth, whose biological role is currently not clear), actively participate in biological processes, are part of many enzymes. According to the classification of N. Reimers, it is difficult to consider metals with a density of more than 8 g / cm 3. Thus, heavy metals include: Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Ng, Pb, VE.

Formally, the determination of heavy metals corresponds to a large number of elements. However, according to researchers engaged in practical activities related to the organization of observations of the state and pollution ambientThe compounds of these elements are far away are not equivalent as pollutants.

Therefore, in many works, the framework of a group of heavy metals occurs, in accordance with the priority criteria, due to the direction and specifics of work.

So, in the already classic work of Yu. A. Israel in the list chemical substancesto be determined in natural environments on background stations in biosphere reserves, in the section Heavy metals, the PB, NG, CU are named.

On the other hand, according to the decision of the Task Force on Emissions of Heavy Metals, working under the auspices of the United Nations Economic Commission and the collection and analysis of information on pollutant emissions in European countries, only Zn, Hg and Pb were attributed to heavy metals.

By definition of N. Reimers, separately from heavy metals are noble and rare metals, respectively, only the RB, Cu, Zn, Ni remain , CO, SN, BE, NG.

In applied works, PT, AU, MN is most often added to the number of heavy metals.

Metal ions are indispensable components of natural reservoirs. Depending on the conditions of the medium (pH, the redox potential, the presence of ligands), they exist in different degrees of oxidation and are part of a variety of inorganic and metallorganic compounds that can be truly dissolved, colloidal-dispersed or enter the mineral and organic suspension.

Truly dissolved forms of metals, in turn, are very diverse, which is associated with the processes of hydrolysis, hydrolytic polymerization (the formation of polyderic hydroxes complexes) and complexing with various ligands.

Accordingly, both the catalytic properties of metals and their accessibility for water microorganisms depend on the forms of their existence in the aquatic ecosystem.

Many metals form pretty strong complexes with an organic; These complexes are one of the most important forms of migration of elements in natural waters.

Most organic complexes are formed by the chelated cycle and are stable. Complexes formed by soil acids with salts of iron, aluminum, titanium, uranium, vanadium, copper, molybdenum and other heavy metals are relatively well soluble in conditions of neutral, weakness and weakly alkaline media. Therefore, the metallurgical complexes are able to migrate in natural waters on very significant distances.

This is especially important for low-mineralized and primarily surface waters, in which the formation of other complexes is impossible.

To understand the factors that regulate the concentration of metal in natural waters, their chemical reactivity, biological accessibility and toxicity, it is necessary to know not only the gross content, but also the share of free and related metal forms.

The transition of metals in an aqueous medium in a metal complex form has three consequences:

1. An increase in the total concentration of metal ions may occur due to the transition to a solution from bottom sediments;

2. The membrane permeability of complex ions can differ significantly from the permeability of hydrated ions;

3. Metal toxicity as a result of complexation can change much.

So, chelated forms CU, PB and NG are less toxic than free ions. To understand the factors that regulate the concentration of metal in natural waters, their chemical reaction capacity, biological accessibility and toxicity, it is necessary to know not only the gross content, but also the share of related and free forms.

Sources of water pollution with heavy metals are the wastewater of electroplating shops, mining, black and non-ferrous metallurgy enterprises, machine-building factories. Heavy metals are part of fertilizers and pesticides and can fall into reservoirs with stock with agricultural land.

Increasing the concentration of heavy metals in natural waters is often associated with other types of pollution, for example, with acidification.

The loss of acid precipitates contributes to a decrease in the pH value and the transition of metals from the state-sorbed on mineral and organic substances into free.

Vanadium

Vanadium is mainly in the scattered state and is found in iron ores, oil, asphalt, bitumens, combustible slates, coals, etc. One of the main sources of pollution of natural waters vanadium are oil and its products.

In natural waters, it is found in a very low concentration: in water water from 0.2 to 4.5 μg / dm 3, in sea water - an average of 2.0 μg / dm 3

In vanadium migration, the role of dissolved complex compounds of it with organic substances is essential, especially with humus acids.

Increased vanadium concentrations are harmful to human health. PDC Vanadium is 0.1 mg / dm 3 (limiting harm difference - sanitary-toxicological) .

Bismuth

Natural sources of bismuth intake in natural waters are the leaching processes of bismuth-containing minerals. The source of admission to natural water can also be the wastewater of pharmaceutical and perfumery industries, some enterprises of the glass industry.

In unpolluted surface waters, it is contained in submicrogram concentrations. The highest concentration is detected in groundwater and is 20 μg / dm 3 , in seawood - 0.02 μg / dm 3 . MPC is 0.1 mg / dm 3 .

Iron

The main sources of iron compounds in surface waters are the processes of chemical weathelation of rocks, accompanied by their mechanical destruction and dissolution. In the process of interaction with the mineral and organic substances contained in natural waters, a complex complex of iron compounds in water in a dissolved, colloid and suspended state is formed. Significant amounts of iron come with an underground drain and with wastewater of enterprises of metallurgical, metalworking, textile, paint industry and agricultural drains.

Phase equilibrium depends on the chemical composition of water, pH and to some extent on temperature. In routine analysis on a suspended form separate particles with a size of more than 0.45 MK. It is predominantly iron-containing minerals, iron oxide hydrate and iron compounds, sorbed on suspension.

Truly dissolved and colloidal form usually consider jointly. The dissolved iron is represented by compounds in ionic form, as hydroxocomplex and complexes with dissolved inorganic and organic substances of natural waters.

In ion form, it migrates mainly Fe (II), and Fe (iii) in the absence of complexing substances cannot be in substantial quantities in a dissolved state.

As a result of chemical and biochemical (with the participation of ferrofackerium), the oxidation of Fe (II) transfers in Fe (III), which, hydrolyzing, falls into the precipitate in the form of Fe (it) 3.

As for Fe (II) and for Fe (iii), a tendency to the formation of hydroxy cells of type +, 4+, +, 3+, and other coexisting in the solution in different concentrations, depending on the pH and as a whole, the state of the iron system - Hydroxyl.

The main form of finding Fe (III) in surface waters are complex compounds with dissolved inorganic and organic compounds, mainly humus substances.

At pH \u003d 8.0, the main form is Fe (OH) 3. Skolloid form of iron is the least studied, it is an iron oxide hydrate (it) 3 and complexes with organic substances.

The greatest concentrations of iron (up to several tens and hundreds of milligrams in 1 dm 3) are observed in groundwater with low pH values.

Being a biologically active element, iron to a certain extent affects the intensity of the development of phytoplankton and the high-quality composition of microflora in the reservoir.

The concentration of iron is subject to noticeable seasonal oscillations. Usually in water bodies with high biological productivity in the period of summer and winter stagnation, an increase in iron concentration in the bottom layers of water is noticeable. Autumn-spring mixing of the aqueous mass (homothermia) is accompanied by oxidation of Fe (II) in Fe (III) and the launcher of the latter in the form of Fe (OH) 3.

Iron MPC is 0.3 mg / dm 3

Cadmium

In natural waters, when leaching soils, polymetallic and copper ores, as a result of the decomposition of aquatic organisms capable of accumulating it.

Cadmium compounds are taken out in surface water with wastewater of lead-zinc plants, rudious factories, a number of chemical enterprises (production of sulfuric acid), electroplating production, as well as with mine waters.

The decrease in the concentration of dissolved cadmium compounds occurs due to the processes of sorption, falling into the precipitate of hydroxide and carbonate cadmium and consumption by their aquatic organisms.

The dissolved cadmium forms in natural waters are mainly mineral and organ-mineral complexes. The main suspended form of cadmium is its sorbed connections. A significant part of cadmium can migrate as part of hydrobionth cells.

In river unpolluted and weakly-discharged waters, cadmium contains in submicrogram concentrations, in contaminated and wastewater concentration of cadmium can reach tens of micrograms in 1 dm 3.

Cadmium compounds play an important role in the process of animal and human life. In elevated concentrations of toxic, especially in combination with other toxic substances.

MPC is 0.001 mg / dm 3 . Limiting sign of harm - toxicological.

Cobalt

The natural water of the cobalt compounds fall as a result of the leaching processes from their medical-grated and other ores, from soils in the decomposition of organisms and plants, as well as with wastewater of metallurgical, metalworking and chemical plants. Some amounts of cobalt come from soil as a result of the decomposition of plant and animal organisms.

Cobalt compounds in natural waters are in a dissolved and weighted state, the quantitative ratio between which is determined by the chemical composition of water, temperature and pH values.

The dissolved forms are represented mainly by complex compounds, including with organic substances of natural waters. Compounds of bivalent cobalt are most characteristic of surface water. In the presence of oxidants, there is an existence in noticeable concentrations of trivalent cobalt.

Cobalt refers to the number of biologically active elements and is always contained in the body of animals and in plants. With insufficient content of it in the soils, the lack of cobalt content in plants is connected, which contributes to the development of Malokrovia in animals (Taiga-Forest Non-Black Zone).

Entering the vitamin B 12, cobalt very actively affects the flow of nitrogenous substances, an increase in the content of chlorophyll and ascorbic acid, activates biosynthesis and increases the content of protein nitrogen in plants. At the same time, the elevated concentrations of cobalt compounds are toxic.

In river unpolluted and low-grade waters, its content ranges from tenths to thousands of milligram in 1 dm 3, the average content in seawater 0.5 μg / dm 3 .

MPC is 0.1 mg / dm 3 .

Manganese

In the surface waters, the manganese comes as a result of leaching with iron ordinary ores and other minerals containing manganese (pyrolyzit, ppylomellan, brawn, manganite, black sockets). Significant amounts of manganese come in the process of decomposition of aquatic animals and vegetable organisms, especially blue-green, diatoms of algae and higher aquatic plants. The compounds of manganese are taken out in water bodies with wastewater of manganese processing factories, metallurgical plants, enterprises of the chemical industry and mine waters.

The decrease in the concentration of manganese ions in natural waters occurs as a result of the oxidation of Mn (II) to MNO 3 and other high-grained oxides falling into the sediment. The main parameters that determine the oxidation reaction is the concentration of dissolved oxygen, the pH value and the temperature. The concentration of dissolved manganese compounds is reduced due to the disposal of their algae.

The main form of migration of manganese compounds in surface waters - suspension, the composition of which is determined by the composition of rocks drained, as well as colloidal hydroxides of heavy metals and sorbed compounds of manganese.

Significant in migration of manganese in dissolved and colloidal forms are organic substances and processing of manganese complexation with inorganic and organic ligands.

Mn (ii) forms soluble complexes with bicarbonates and sulfates. Manganese complexes with chlorine ion are rare.

Complex compounds Mn (II) with organic substances are usually less durable than with other transition metals. These include compounds with amines, organic acids, amino acids and humus substances.

Mn (iii) in elevated concentrations may be in a dissolved state only in the presence of strong complexes.

Mn (vi) in natural waters does not occur.

In river waters, manganese contents usually range from 1 to 160 μg / dm 3 , average content in sea waters is 2 μg / dm 3 .

The concentration of manganese in surface waters is subject to seasonal oscillations.

The factors determining changes in the concentrations of manganese are the ratio between the surface and underground flow, the intensity of its consumption in photosynthesis, the decomposition of phytoplankton, microorganisms and higher water vegetation, as well as the processes of deposition of it on the bottom water objects.

The role of manganese in life higher Plants And the algae of water bodies is very large. Manganese promotes recycling with 2 plants than increasing the intensity of photosynthesis, participates in the processes of restoration of nitrates and nitrogen assimilation by plants. Manganese promotes the transition of active Fe (II) in Fe (W), which protects the cell from poisoning, accelerates the growth of organisms, etc. An important environmental and physiological role of manganese causes the need to study and distribute manganese in natural waters.

For sanitary water reservoirs, a manganese ion is installed on a manganese ion, equal to 0.1 mg / dm 3 .

Copper

Copper is one of the most important trace elements. The physiological activity of copper is mainly related to the inclusion of it in the active centers of redox enzymes. The insufficient copper content in soils adversely affects the synthesis of proteins, fats and vitamins and contributes to the infertility of plant organisms.

Copper is involved in the process of photosynthesis and affects the absorption of nitrogen by plants. At the same time, excessive copper concentrations have an adverse effect on plant and animal organisms.

In natural waters, Cu (II) compounds are most often found.

From compounds Cu (i), the most commonly soluble in water Cu 2 O, Cu 2 S, SUSL. If there are ligands in the aqueous medium, along with the equilibrium of the dissociation of hydroxide, it is necessary to take into account the formation of various complex forms that are in equilibrium with metal aquaions.

The main source of copper intake in natural water is the wastewater of enterprises of the chemical, metallurgical industry, mine waters, aldehyde reagents used to destroy algae. Copper may appear as a result of corrosion of copper pipelines and other structures used in water supply systems. In the underground waters, the copper content is due to the interaction of water with rocks containing it (chalcopyrite, chalcozin, Kovellin, Bornech, Malachite, Azurit, Khryscollah, Brittin).

The maximum allowable concentration of copper in water of sanitary water use water bodies is 0.1 mg / dm 3 (The limiting sign of harm is generalized).

Molybdenum

Molybdenum compounds fall into surface water as a result of leaching them from exogenous minerals containing molybdenum. Molybdenum enters the reservoirs also with the wastewater of the processing factories, non-ferrous metallurgy enterprises. The decrease in the concentrations of compounds of molybdenum occurs as a result of a precipitate of difficult soluble compounds, the processes of adsorption of mineral suspenders and consumption by vegetable water organisms.

Molybdenum in surface waters is mainly in the form of MoO 4 -2. There is probably the existence of it in the form of organicineral complexes. The possibility of some accumulation in colloidal state follows from the fact that the products of oxidation of molybdenite represent loose fine substances.

In river waters, molybdenum was found in concentrations from 2.1 to 10.6 μg / dm 3. In seawater, it contains an average of 10 μg / dm 3 molybdenum.

In small quantities, molybdenum is necessary for the normal development of plant and animal organisms. Molybdenum is part of the Ksantinoxidase enzyme. With a deficiency of molybdenum, the enzyme is formed in insufficient quantity, which causes negative reactions of the body. In elevated concentrations, molybdenum is harmful. With an excess of molybdenum, metabolism is violated.

The maximum permissible concentration of molybdenum in sanitary water reservoirs is 0.25 mg / dm 3 .

Arsenic

In the natural waters, arsenic comes from mineral springs, regions of arsenic chopper (arsenic cchedan, realgar, aurapygiment), as well as from the oxidation zones of rocks of polymetallic, copper-cobalt and tungsten types. A certain amount of arsenic comes from soils, as well as as a result of the decomposition of plant and animal organisms. Arsenic consumption by aquatic organisms is one of the reasons for lowering it in water, the most distinctly manifested during the period of intensive development of plankton.

Significant amounts of arsenic enter water facilities with waters of processing factories, the waste from the production of dyes, leather factories and enterprises producing pesticides, as well as from agricultural land on which pesticides are applied.

In natural waters, arsenic compound is in a dissolved and balanced state, the ratio between which is determined by the chemical composition of water and pH values. In dissolved form of arsenic, it is found in three- and five-length form, mainly in the form of anions.

In river unpolluted waters, arsenic is usually in microgram concentrations. In the mineral waters, its concentration can reach several milligrams in 1 dm 3, in marine waters, on average, contains 3 μg / dm 3.

The arsenic compounds in elevated concentrations are toxic for the organism of animals and humans: they slow down oxidative processes, inhibit the supply of organs and tissues.

Mysteria PDC is 0.05 mg / dm 3 (limiting harm difference - sanitary-toxicological)

Nickel

The presence of nickel in natural waters is due to the composition of rocks through which water passes. It is found in places of sulfide copper-nickel ore and iron-nickel ores. In the water hits with soils and from plant and animal organisms when they are decayed.

The content of nickel compared to other types of algae is detected in blue-green algae. Nickel compounds in water bodies also come with wastewater of nickel planting shops, synthetic rubber plants, nickel processing factories. Huge nickel emissions accompany fossil fuel burning.

The concentration of it can be reduced as a result of falling out of compounds such as cyanides, sulphides, carbonates or hydroxides (with an increase in pH values), due to consumption by its aquatic organisms and adsorption processes.

In the surface waters of nickel compounds are in a dissolved, weighted and colloidal state, the quantitative ratio between which depends on the composition of water, temperature and pH values. Sorbents of nickel compounds can be iron hydroxide, organic substances, highly dispersed calcium carbonate, clay. Molted forms are mainly complex ions, most often with amino acids, humic and fulvocosloids, as well as in the form of a solid cyanide complex. The most common in the natural waters of the nickel compound in which it is in the degree of oxidation is +2. Ni 3+ compounds are usually formed in an alkaline environment.

Nickel compounds play an important role in hematopoietic processes, being catalysts. Increased content has a specific effect on the cardiovascular system. Nickel belongs to the number of carcinogenic elements. It is able to cause respiratory diseases. It is believed that free nickel ions (Ni 2+) are about 2 times more toxic than its complex compounds.

In river unpolluted and low-grade waters, the concentration of nickel varies from 0.8 to 10 μg / dm 3; In contaminated, it is a few dozen micrograms of 1 dm 3. The average nickel concentration in sea water is 2 μg / dm 3.

Tin

The natural waters comes as a result of the leaching processes of tin-containing minerals (cassiterit, station), as well as with wastewater of various industries (dyeing tissues, synthesis of organic paints, production of alloys with tin additive, etc.).

The toxic effect of tin is small.

In unpolluted surface waters, tin is contained in submicrogram concentrations. In the underground waters, its concentration reaches the units of micrograms in 1 dm 3 . MPC is 2 mg / dm 3 .

Mercury

In surface waters, mercury compounds can be treated as a result of leaching of rocks in the area of \u200b\u200bmercury deposits (cinnabar, metacinbarrit, Livingstonite), in the process of decomposition of aquatic organisms accumulating mercury.

Significant quantities enter water bodies with wastewater enterprises producing dyes, pesticides, pharmaceutical preparations, some explosives. Thermal coal power plants emit significant amounts of mercury compounds into the atmosphere, which, as a result of wet and dry drops, fall into water bodies.

The decrease in the concentration of dissolved mercury compounds occurs as a result of extracting them with many marine and freshwater organisms, which have the ability to accumulate it in concentrations, many times greater than its content in water, as well as adsorption processes of suspended substances and bottom sediments.

In the surface waters of mercury compounds are in a dissolved and weighted state. The ratio between them depends on the chemical composition of water and pH values. Weighted mercury is a sorbed mercury compounds. Dissolved forms are unfinished molecules, complex organic and mineral connections. In the water of water bodies, mercury may be in the form of methyl rat connections.

Mercury compounds are highly toxic, they affect nervous system Human, cause changes from the mucous membrane, violation of the motor function and secretion of the gastrointestinal tract, changes in the blood, etc. Bacterial methylation processes are aimed at the formation of methyl ratings, which are many times toxic mercury mineral salts. Methylratic compounds accumulate in fish and can fall into the human body.

MPC Mr. is 0.0005 mg / dm 3 (limiting sign of harm – Sanitary and toxicological).

Lead

Natural sources of lead arrival in surface waters are the processes of dissolution of endogenous (galvanit) and exogenous (engines, cerussite, etc.) minerals.

A significant increase in the lead of lead in the environment (including and in surface waters) is associated with the burning of coal, using tetraeethylswin as an anti-knock at motor fuel, with a removal of water plants with the wastewater of erecting mills, some metallurgical plants, chemical industries, mines, etc.

The essential factors of lowering lead concentration in water are adsorption of its suspended substances and deposition with them into bottom sediments. Among other metals, lead is extracted and accumulated by hydrobionts.

Lead is in natural waters in a dissolved and weighted (sorbed) state. In dissolved form, it is found in the form of mineral and organic-mineral complexes, as well as simple ions, in insoluble - mainly in the form of sulfides, sulfates and carbonates.

In the river waters, lead concentration ranges from a tenth of a fraction to the units of micrograms in 1 dm 3. Even in the water of water objects adjacent to the areas of polymetallic ores, its concentration rarely reaches tens of milligrams in 1 dm 3. Only in chloride thermal waters, the lead concentration sometimes reaches several milligrams of 1 dm 3.

Lead - industrial poison capable of adverse conditions. The human body penetrates mainly through respiratory and digestion organs. It is removed from the body very slowly, as a result of which accumulates in the bones, liver and kidneys.

The limiting indicator of the harmful lead is sanitary-toxicological. MPC, lead is 0.03 mg / dm 3 .

Tetraethylswin

Enters natural water due to the use of water vehicles as an anti-knock in motor fuel, as well as with superficial drain from urban areas.

This substance is characterized by high toxicity, has cumulative properties.

Silver

Sources of silver admission to surface water are groundwater and wastewater of mines, processing factories, photocrediting materials. Increased silver content is associated with the use of bactericidal and algicide preparations.

IN wastewaterah silver may be present in a dissolved and suspended form, mostly in the form of halogen salts.

In unpolluted surface waters, silver is in submicrogram concentrations. In the underground waters, silver concentration ranges from units to tens of micrograms in 1 dm 3, in sea water - an average of 0.3 μg / dm 3.

Silver ions are able to destroy bacteria and already in a minor concentration sterilize water (lower limit of bactericidal action of silver ions 210 mol / dm 3). The role of silver in the body of animals and humans is not well understood.

PDC silver is 0.05 mg / dm 3 .

Antimony

The antimony enters surface waters through the leaching of antimony minerals (stubnit, senarmontitis, valentinesit, servantitis, styling) and with wastewater rubber, glass, dyeing, match enterprises.

In natural waters, antimony compounds are in a dissolved and balanced state. In the redox conditions characteristic of surface water, the existence of both trivalent and five-channel antimony is possible.

In unpolluted surface waters, antimony is in submicrogram concentrations, in seawater its concentration reaches 0.5 μg / dm 3, in groundwater - 10.0 μg / dm 3.

PDC antimony is 0.05 mg / dm 3 (limiting harmfulness - sanitary-toxicological ).

Chromium

The surface waters of the compound of three- and hexavalent chromium are falling as a result of leaching from rocks (chrome, croacy, respect, etc.). Some quantities come in the process of decomposition of organisms and plants, from soil.

Significant quantities can flow into water bodies with wastewater electroplating shops, critical shops of textile enterprises, leather factories and chemical industries. The decrease in the concentration of chrome ions may be observed as a result of consumption by their aquatic organisms and adsorption processes.

In the surface waters of chromium compounds are in dissolved and suspended states, the ratio between which depends on the composition of water, temperature, pH of the solution. Weighted chromium compounds are mainly sorbed chromium compounds.

Sorbents can be clay, iron hydroxide, highly dispersed calcium carbonate, remains of plant and animal organisms. In a dissolved form, chromium may be in the form of chromates and bichromates. In aerobic conditions, Cr (VI) proceeds to CR (III), the salt of which in neutral and alkaline media is hydrolyzed with the release of hydroxide.

In river unpolluted and low-grade waters, the chromium content ranges from several tenths of a microgram in a liter to several micrograms in liter, in contaminated water bodies it reaches several tens and hundreds of micrograms in liter. The average concentration in marine waters is 0.05 μg / dm 3.

CR (VI) and CR (III) compounds in elevated amounts have carcinogenic properties. CR (VI) compounds are more dangerous.

Zinc

It falls into natural waters as a result of the processes of destruction and dissolution of rocks and minerals (sphalerite, zincite, smits, Kalamin), as well as with the wastewater of erecting plants and electroplating workshops, parchment paper productions, mineral paints, viscose fiber, etc.

In water, there is mainly in ion form or in the form of its mineral and organic complexes. Sometimes it is found in insoluble forms: in the form of hydroxide, carbonate, sulfide, etc.

In river waters, zinc concentration usually ranges from 3 to 120 μg / dm 3, in marine - from 1.5 to 10.0 μg / dm3. The content in ore and especially in mine waters with low pH values \u200b\u200bcan be significant.

Zinc refers to the number of active trace elements affecting the growth and normal development of organisms. At the same time, many zinc compounds are toxic, first of all, its sulfate and chloride.

MPC is 1 mg / dm 3 (The limiting index of harm is organoleptic).

Do not everyone know what chemical elements are still included in this category. There are a lot of criteria for which, different scientists determine heavy metals: toxicity, density, atomic weight, biochemical and geochemical cycles, distribution in nature. According to the criteria, the number of heavy metals includes arsenic (metalloid) and bismuth (fragile metal).

General Facts about Heavy Metals

More than 40 elements are known that belong to heavy metals. They have an atomic mass of more than 50 A.E. How it is not strange that these elements have a large toxicity even with a small cumulation for living organisms. V, CR, MN, FE, CO, NI, CU, ZN, MO ... PB, HG, U, TH ... All of them are included in this category. Even with their toxicity, many of them are important trace elements, except for cadmium, mercury, lead and bismuth for which they did not find a biological role.

On another classification (namely N. Reymmers), heavy metals are elements that have a density greater than 8 g / cm 3. Thus, there are fewer such elements: PB, Zn, Bi, SN, CD, CU, NI, CO, SB.

Theoretically, heavy metals can be called the entire table of Mendeleev's elements since Vanadium, but researchers prove to us that it is not quite so. Such a theory is caused by the fact that not all of them are present in nature in the toxic limits, and confusion in biological processes for many minimal. That is why in this category many include only lead, mercury, cadmium and arsenic. The UN Economic Commission does not agree with this opinion and believes that heavy metals are zinc, arsenic, selenium and antimony. The same N. Reimers believes that removal of rare and noble elements from the Mendeleev table remain heavy metals. But this is also not a rule, others add and gold, platinum, silver, tungsten, iron, manganese add to this class. That's why I tell you that not still understandable on this topic ...

Discussing the balance of ions of various substances in the solution, we find that the solubility of such particles is associated with many factors. The main solubilization factors are pH, the presence of ligands in solution and redox potential. They are involved in the oxidation processes of these elements with one oxidation degree to another, in which the solubility of the ion in the solution is higher.

Depending on the nature of the ions, various processes may occur in solution:

• hydrolysis,
• complexation with different ligands;
• hydrolytic polymerization.

Because of these processes, ions can be precipitated or remain stable in solution. The catalytic properties of a particular element, and its availability for living organisms depends on it.

Many heavy metals form quite stable complexes with organic substances. These complexes are included in the migration mechanism of these elements in ponds. Almost all chelated heavy metals complexes are resistant in solution. Also, complexes of soil acids with salts of different metals (molybdenum, copper, uranium, aluminum, iron, titanium, vanadium) have good solubility in neutral, weakly alkaline and weakness medium. This fact is very important, because such complexes can move in a dissolved state over long distances. The most susceptible water resources are low-mineralized and surface reservoirs, where other such complexes do not occur. To understand the factors that regulate the level of the chemical element in rivers and lakes, their chemical reaction capacity, biological accessibility and toxicity, it is necessary to know not only gross content, but also the share of free and related metal forms.

As a result of migration of heavy metals in metal complexes in solution, such consequences may occur:

1. In the first, the cumulation of the chemical element ions increases due to the transition of these from bottom deposits into natural solutions;
2. Secondly, it is possible to change the membrane permeability of the obtained complexes in contrast to ordinary ions;
3. Also, the toxicity of the element in a comprehensive form may differ from the usual ion form.

For example, cadmium, mercury and copper into chelated forms have less toxicity than free ions. That is why it is not correct to talk about toxicity, biological accessibility, chemical reactivity only by total content A certain element, while not considering the share of free and related forms of the chemical element.

Where do heavy metals come from our habitat? The reasons for the presence of such elements may be wastewater from different industrial facilities engaged in black and non-ferrous metallurgy, mechanical engineering, galvanization. Some chemical elements are included in pesticides and fertilizers and thus can be a source of pollution of local ponds.

And if you enter the secrets of chemistry, then the most important culprit of raising the level of soluble heavy metals salts is acidic rain (acidification). A decrease in the acidity of the medium (reducing pH) is drawn by the transition of heavy metals from low-soluble compounds (hydroxides, carbonates, sulfates) to more well soluble (nitrates, hydrosulfates, nitrites, hydrocarbonates, chlorides) in soil solution.

Vanadium (V)

It should be noted primarily that the contamination by this element is unlikely to be unlikely, because this element is very distant in the earth's crust. In nature, it is found in asphalt, bitumens, coals, iron ores. An important source of pollution is oil.

Vanadium content in natural reservoirs

Natural reservoirs contains an insignificant amount of vanadium:

• in rivers - 0.2 - 4.5 μg / l,
• in the seas (on average) - 2 μg / l.

In the processes of the vanadium transition in a dissolved state, anionic complexes (V 10 O 26) 6- and (V 4 O 12) 4- are very important. Also, soluble vanadium complexes with organic substances, such as humus acids are also very important.

Maximum permissible concentration of vanadium for an aquatic environment

Vanadium in elevated doses is very harmful to humans. The maximum permissible concentration for the aqueous medium (MPC) is 0.1 mg / l, and in fishery ponds, PDK Rykhoz is even lower than 0.001 mg / l.

Bismuth (BI)

Mostly, bismuth can flow into rivers and lakes as a result of the leaching processes of minerals containing bismuth. There are technogenic sources of pollution by this element. These can be enterprises for the production of glass, perfume products and pharmaceutical factories.

Bismuth content in natural reservoirs

• Rivers and lakes contain less bismuth microgram per liter.
• But groundwater may contain even 20 μg / l.
• In the seas bismuth as a rule does not exceed 0.02 μg / l.

Maximum permissible bismuth concentration for aquatic environment

PDC bismuth for an aqueous medium - 0.1 mg / l.

Iron (FE)

Iron - chemical element is not rare, it is contained in many minerals and rocks and thus in natural reservoirs the level of this element is higher than other metals. It can occur as a result of the weathering processes of rocks, the destruction of these breeds and dissolution. Arriving different complexes with organic substances from the solution, iron can be in colloidal, dissolved and in suspended states. It is impossible not to mention the anthropogenic sources of pollution with iron. Waste water with metallurgical, metalworking, paints and textile plants are sometimes excavated due to excess iron.

The amount of iron in rivers and lakes depends on the chemical composition of the solution, pH and partly on temperature. Weighted forms of iron compounds have a size of more than 0.45 μg. The main substances that are part of these particles are suspension with sorbed gland compounds, iron oxide hydrate and other iron-containing minerals. Smaller particles, that is, colloidal iron forms are treated together with dissolved iron compounds. The iron in the dissolved state consists of ions, hydroxamplexes and complexes. Depending on the valence, it is noticed that FE (II) migrates in ion form, and Fe (III) in the absence of different complexes remains in a dissolved state.

The balance of iron compounds in an aqueous solution is very important and the role of oxidation processes, so chemical and biochemical (ferruplate). These bacteria are responsible for moving iron ions Fe (II) to the state Fe (III). The compounds of trivalent iron have a tendency to hydrolyze and fall out of FE (OH) 3. Both Fe (II) and Fe (III) slopes to the formation of type hydroxocomplexes -, +, 3+, 4+, +, depending on the acidity of the solution. Under normal conditions, in rivers and lakes, Fe (III) are due to different dissolved inorganic and organic substances. At pH, more than 8, Fe (III) goes to Fe (OH) 3. Colloidal forms of iron compounds are the most poorly studied.

Iron content in natural reservoirs

In rivers and lakes, the iron level ranges at N * 0.1 mg / l, but may increase near the marshes to several mg / l. In the swamps of iron concentrates in the form of salts of humate (slices of humic acids).

Underground reservoirs with low pH contain record amounts of iron - up to several hundred milligrams per liter.

Iron - an important trace element and different important biological processes depend on it. It affects the intensity of the development of phytoplankton and the quality of microflora in reservoirs depends on it.

Iron level in rivers and lakes has a seasonal character. The highest concentrations in reservoirs are observed in winter and summer due to the stagnation of water, but the level of this element due to the mixing of the aqueous mass is significantly reduced in the spring and autumn.

Thus, a large amount of oxygen leads to oxidation of iron from a bivalent shape in trivalent, forming iron hydroxide, which falls into the precipitate.

Maximum permissible concentration of iron for the aquatic environment

Water with a large amount of iron (more than 1-2 mg / l) is characterized by bad taste. It has an unpleasant astringent taste and unsuitable for industrial purposes.

Iron MPC for an aqueous medium - 0.3 mg / l, and in fishery ponds PDC fishoz - 0.1 mg / l.

Cadmium (CD)

Pollution by cadmium may occur during the leaching of soils, with the decomposition of different microorganisms that accumulate it, as well as due to migration from copper and polymetallic ores.

Man is also to blame for pollution by this metal. Wastewater from various enterprises engaged in erecting, electroplated, chemical, metallurgical production may contain large amounts of cadmium compounds.

Natural processes to reduce the level of cadmium compounds are sorption, its consumption by microorganisms and the precipitate of a low-soluble cadmium carbonate.

In solution, cadmium is, as a rule, in the form of organo-mineral and mineral complexes. Sorbed substances based on cadmium are the most important weighted forms of this element. The migration of cadmium in living organisms (hydrobionits) is very important.

Cadmium content in natural reservoirs

The cadmium level in pure rivers and lakes fluctuates less than a microgram per liter, in contaminated waters, the level of this element comes to several micrograms per liter.

Some researchers believe that cadmium, in small quantities, can be important for the normal development of animals and humans. Increased cadmium concentrations are very dangerous for living organisms.

Maximum permissible concentration of cadmium for the aquatic environment

The MPC for the aqueous medium does not exceed 1 μg / l, and in the fishery ponds, the PDC fishoz is less than 0.5 μg / l.

Cobalt (CO)

Rivers and lakes can be contaminated with cobalt as a consequence of leaching copper and other ores, from soil during the decomposition of extinct organisms (animals and plants), and of course as a result of the activity of chemical, metallurgical and metalworking enterprises.

The main forms of cobalt compounds are in dissolved and suspended states. Variations between these two states can occur due to changes in pH, temperature and solution composition. In a dissolved state, cobalt is contained in the form of organic complexes. Rivers and lakes have the characterity that cobalt is represented by a bivalent cation. If there are a large amount of oxidizing agents in the solution, cobalt can oxide to the trivalent cation.

It is part of plants and animals, because he plays an important role in their development. Is among the main trace elements. If the cobalt deficiency is observed in the soil, then its level in plants will be less than usual and, as a result, problems with health in animals may appear (the risk of anemia arises). This fact is observed especially in the Taiga-Forest Non-Black Zone. It is part of vitamin B 12, regulates the absorption of nitrogenous substances, increases the level of chlorophyll and ascorbic acid. Without it, plants cannot increase the required amount of protein. Like all heavy metals, it can be toxic in large quantities.

Cobalt content in natural reservoirs

• The level of cobalt in rivers varies from several micrograms to milligrams per liter.
• In the seas, on average, the cadmium level is 0.5 μg / l.

Maximum permissible cobalt concentration for an aquatic environment

PDC cobalt for an aqueous medium - 0.1 mg / l, and in fishery ponds PDC fish farms - 0.01 mg / l.

Manganese (MN)

The manganese enters the river and lakes along the same mechanisms as iron. Mostly, the release of this element in the solution occurs when leaching minerals and ores, which contain manganese (black ocher, brownit, pyrolyzit, psychoshelan). Also, the manganese can come as a result of the decomposition of different organisms. Industry has, I think, the greatest role in the pollution of manganese (wastewater from mines, chemical industry, metallurgy).

A decrease in the amount of digestible metal in the solution occurs, as in the case of other metals in aerobic conditions. Mn (ii) is oxidized to Mn (IV), as a result of which falls into a precipitate in the form of MNO 2. An important factors at such processes are the temperature, the amount of dissolved oxygen in solution and pH. The decrease in dissolved manganese in the solution may occur when using algae.

Migrating the manganese mainly in the form of suspension, which, as a rule, talk about the composition of the surrounding rocks. It is contained as a mixture with other metals in the form of hydroxides. The predominance of manganese in colloidal and dissolved form suggest that it is associated with organic compounds forming complexes. Stable complexes are noted with sulphates and bicarbonates. With chlorine, the manganese forms complexes less often. Unlike other metals, it is weaker to hold in the complexes. The trivalent manganese forms such compounds only in the presence of aggressive ligands. Other ionic forms (Mn 4+, Mn 7+) are less rare or not at all occur in conventional conditions in rivers and lakes.

Manganese content in natural reservoirs

The most poor in the manganese is considered to be 2 μg / l, its contents are more to 160 μg / l, and the underground reservoirs and this time are record holders - from 100 μg to several mg / l.

For manganese, seasonal oscillations of concentration, as well as in iron, are characteristic.

Many factors have been revealed that affect the level of free manganese in the solution: the connection of rivers and lakes with underground reservoirs, the presence of photosynthesising organisms, aerobic conditions, biomass decomposition (dead organisms and plants).

The important biochemical role of this element is it in the group of trace elements. Many processes in the manganese deficiency are oppressed. It increases the intensity of photosynthesis, participates in nitrogen metabolism, protects cells from the negative effects of Fe (II) at the same time oxidizing it in a trivalent shape.

Maximum permissible manganese concentration for an aquatic environment

MANGAND MANGAND for water bodies - 0.1 mg / l.

Copper (CU)

Such an important role for living organisms has no trace element! Copper is one of the most sought-after trace elements. It is part of many enzymes. Without it, almost nothing works in a living organism: the synthesis of proteins, vitamins and fats is disturbed. Without it, plants cannot multiply. Still, the excess amount of copper causes large intoxication in all types of living organisms.

Copper level in natural reservoirs

Although copper has two ionic forms, the Cu (II) is found in the solution. Usually, Cu (I) compounds are difficult soluble in solution (Cu 2 S, CUCl, Cu 2 O). Different copper aquaeons may occur if any ligands have.

In today's high consumption of copper in industry and agriculture, this metal can cause environmental pollution. Chemical, metallurgical plants, mines can be sources of wastewater with high copper content. Pipeline erosion processes also have their contributions to copper pollution. Malachit, Bornete, Halcopyrite, Halcozin, Azurist, Bronctin are considered the most important minerals with a large content of copper.

Maximum permissible copper concentration for aquatic environment

Copper MPC for an aqueous medium is considered to be 0.1 mg / l, in the fishery ponds of the PDC fish farm reduces to 0.001 mg / l.

Molybdenum (MO)

During the leaching of minerals with a high content of molybdenum, different compounds of molybdenum are exempt. The high level of molybdenum can be seen in rivers and lakes that are located next to the enrichment factories and non-ferrous metallurgy enterprises. Due to different processes of deposition of hard-soluble compounds, adsorption on the surface of different rocks, as well as use by aqueous algae and plants, its amount may significantly decrease.

Basically in solution, molybdenum may be in the form of anion Moo 4 2-. There is a possibility of the presence of molybdenumorganic complexes. Due to the oxidation of molybdenite, loose finely dispersed compounds are formed, the level of colloidal molybdenum increases.

Molybdenum content in natural reservoirs

The molybdenum level in rivers varies between 2.1 and 10.6 μg / l. In the seas and oceans, its content is 10 μg / l.

At low concentrations, molybdenum helps the normal development of the body (so vegetable, like an animal), because it is included in the category of microelements. He is also part of Different enzymes as xanthinoxylase. With a lack of molybdenum, this enzyme deficiency arises and thus negative effects may appear. The excess of this element is also not welcome, because the normal metabolism is disturbed.

The maximum permissible concentration of molybdenum for the aquatic environment

Molybdenum PDC in surface reservoirs should not exceed 0.25 mg / l.

Arsenic (AS)

The arsenic is polluted mainly areas that are close to mineral mines with a high content of this element (tungsten, copper-cobalt, polymetallic ores). A very small amount of arsenic may occur during the decomposition of living organisms. Due to water organisms, it can be assumed by these. Intensive learning of arsenic from the solution is noticed during the rapid development of plankton.

The most important pollutants of arsenic are the processing industry, enterprises for the production of pesticides, dyes, as well as agriculture.

Lakes and rivers contain arsenic in two states: in suspended and dissolved. The proportions between these forms may vary depending on the pH of the solution and the chemical composition of the solution. In a dissolved state, arsenic can be trivalent or fifty, entering the anionic forms.

The level of arsenic in natural reservoirs

In rivers, as a rule, arsenic content is very low (at the level of MKG / L), and in the seas - on average 3 μg / l. Some mineral water May contain large quantities of arsenic (up to several milligrams per liter).

Most arsenic can contain underground reservoirs - up to several tens of milligrams per liter.

Its connections are very toxic for all animals and for humans. In large quantities, oxidation processes and oxygen transportation to cells are disturbed.

Maximum permissible concentration of arsenic for the aquatic environment

PDC arsenic for an aqueous medium - 50 μg / l, and in fishery ponds PDC fishoz - also 50 μg / l.

Nickel (NI)

The content of nickel in lakes and rivers are affected by local rocks. If the fields of nickel and iron-nickel ores are located near the reservoir, there may be even more normal. Nickel can go into lakes and rivers when placing plants and animals. Blue-green algae contain record amounts of nickel compared to other vegetable organisms. Important waste water with a high content of nickel is exempt in the production of synthetic rubber, during nickelory processes. Also, nickel in large quantities is released during coal burning, oil.

The high pH may cause nickel's precipitation in the form of sulfates, cyanides, carbonates or hydroxides. Live organisms can reduce the level of mobile nickel by using it. The processes of adsorption on the surface of rocks are important.

Water may contain nickel in dissolved, colloidal and suspended forms (the balance between these states depends on the pH of the medium, temperature and composition of water). Iron hydroxide, calcium carbonate, clay is well sorbed compounds containing nickel. Dissolved nickel is in the form of complexes with fulvic and humic acids, as well as with amino acids and cyanides. The most stable ion form is considered Ni 2+. Ni 3+ is usually formed with a large pH.

In the mid-50th anniversary, Nickel was listed in the list of trace elements, because it plays an important role in different processes as a catalyst. In low doses, it has a positive effect on hematopoietic processes. Large doses are still very dangerous for health, because nickel is a carcinogenic chemical element and can provoke different diseases of the respiratory system. Free Ni 2+ is more toxic than in the form of complexes (about 2 times).

Nickel level in natural reservoirs

Maximum permissible nickel concentration for aquatic environment

Nickel PDC for an aqueous medium - 0.1 mg / l, but in fishery ponds PDC fishoz - 0.01 mg / l.

Tin (SN)

Natural sources of tin are minerals that contain this element (stannin, cassiteritis). Anthropogenic sources are factories and factories for the production of different organic paints and the metallurgical industry working with the addition of tin.

Tin - low-toxic metal, which is why using food from metal canned we risk their health.

Lakes and rivers contain less than a tin microgram per liter of water. Underground reservoirs may contain several tin micrograms per liter.

Maximum permissible tin concentration for the aquatic environment

PDC tin for an aqueous medium - 2 mg / l.

Mercury (HG)

Mostly, the elevated level of mercury in water is noticed in areas where there is mercury deposits. The most frequent minerals - Livingstonite, cinnabar, metacinnabarite. Sewer water from enterprises for the production of various drugs, pesticides, dyes may contain important amounts of mercury. Another important source of pollution of mercury is thermal power plants (which use as fuel coal).

Its level in the solution decreases mainly due to marine animals and plants that accumulate and even concentrate mercury! Sometimes the mercury content in marine inhabitants rises several times more than in the marine environment.

Natural water contains mercury in two forms: weighted (in the form of sorbed compounds) and dissolved (complex, mineral mercury compounds). In certain areas of the oceans, mercury may appear in the form of methyl price complexes.

Mercury and its connections are very toxic. At large concentrations, it has a negative effect on the nervous system, provokes changes in the blood, affects the secretion of the digestive tract and the motor function. Mercury processing products are very dangerous by bacteria. They can synthesize organic substances based on mercury, which are many times toxic inorganic compounds. When drinking fish, mercury compounds can get into our body.

Maximum permissible concentration of mercury for the aquatic environment

PDC of mercury in ordinary water - 0.5 μg / l, and in fishery ponds PDC fishoz - less than 0.1 μg / l.

Lead (PB)

Rivers and lakes can be contaminated by lead natural way when washing the lead minerals (galvanit, english, cerussite) and anthropogenic way (coal burning, the use of tetraethylswin in fuel, discharges for eating factories, wastewater from mines and metallurgical plants). The deposition of lead compounds and the adsorption of these substances on the surface of different breeds are essential natural methods for lowering its level in solution. From biological factors, hydrobionts are conducted to reduce the level of lead in solution.

Lead in rivers and lakes is located in suspended and dissolved form (mineral and organic and mineral complexes). Also, lead is in the form of insoluble substances: sulfates, carbonates, sulphides.

Lead content in natural reservoirs

We are heard about the toxicity of this heavy metal. It is very dangerous even with small quantities and can cause intoxication. The penetration of lead in the body is carried out through the respiratory and digestive system. Its selection from the body proceeds very slowly, and it is able to accumulate in the kidneys, bones and liver.

Maximum permissible lead concentration for aquatic environment

PDC lead for an aqueous medium - 0.03 mg / l, and in fishery ponds MPK fishoz - 0.1 mg / l.

Tetraethylswin

It serves as an anti-knock at motor fuel. Thus, the main sources of pollution by this substance are vehicles.

This compound is very toxic and can accumulate in the body.

Maximum allowable concentration of tetraethylswin for an aquatic environment

The maximum permissible level of this substance is approaching zero.

Tetraethylswisen is not allowed in the composition of water.

Silver (AG)

Silver mainly falls into the rivers and lakes from underground reservoirs and as a result of wastewater discharge from enterprises (photopripses, enrichment factories) and mines. Another source of silver can be algicide and bactericidal agents.

In solution, the most important compounds are halogen salts of silver.

Silver content in natural reservoirs

In pure rivers and lakes, silver content - less than a microgram per liter, in the seas - 0.3 μg / l. Underground reservoirs contain up to several dozen micrograms per liter.

Silver in ionic form (at certain concentrations) has a bacteriostatic and bactericidal effect. In order to be able to sterilize water with silver, its concentration must be greater than 2 * 10 -11 mol / l. The biological role of silver in the body is still not known enough.

Maximum allowable silver concentration for the aquatic environment

Maximum allowable silver for an aqueous medium - 0.05 mg / l.

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State Standard of the Russian Federation

Protection of Nature

Soil

Requirements for the properties of sewage precipitation
When using them as fertilizers

State Standard of Russia

Moscow

Preface

1 developed by OJSC Research Institute of Communal Water Supply and Water Cleaning ";

All-Russian Research and Design and Technological Institute of Organic Fertilizers;

Human ecology and environmental hygiene them. A. N. Sysin Ramna;

Scientific Research Institute for Agricultural Use of Wastewater "Progress";

All-Russian Research Institute for Fertilizers and Agricultural Sciences. D.N. Snidishnikova

Submitted by the Technical Committee on Standardization No. 409 "Protection of the Environmental Environment"

2 adopted and put into effect by the Resolution of the State Standard of Russia dated January 23, 2001 No. 30-st

3 In this standard, the provisions are implemented. federal laws "On the waste of production and consumption", "On the sanitary and epidemiological well-being of the population", "On the safe handling of pesticides and agrochemicals"

4 introduced for the first time

GOST R 17.4.3.07-2001

State Standard of the Russian Federation

Protection of Nature

Soil

Requirements for sewage precipitation properties when using them as fertilizers

Nature Protection. SOILS. Requirements for FERTAGE Sludge Use for Fertilization

Date of introduction 2001-10-01

1 area of \u200b\u200buse

This standard establishes basic requirements for sewage precipitation properties when using them as fertilizers, as well as environmental requirements.

This standard applies to precipitation formed during the purification of household, urban (mixtures of household and industrial), as well as close to them in the composition of industrial wastewater and products (fertilizers) based on precipitation (hereinafter referred).

Standard does not apply to precipitation manufacturing enterprises (enterprises of pulp and paper, chemical, including the production of synthetic rubber, chemical fiber, chemicals Plant protection, petrochemical and other industries), in the wastewater of which may contain toxic organic substances of the first and second hazard class in quantities exceeding their maximum permissible concentrations (MPC) in water of water bodies.

The requirements of the standard are mandatory for communal services Municipal I. departmental enterprises and organizations with the right to supply and use precipitation as fertilizers in agriculture, industrial flower growing, green construction, forest and ornamental nurseries, as well as for biological reclamation of impaired land and polygons of solid household waste (MSW).

2 Regulatory references

This standard uses links to the following standards:

Protection of Nature. Soil. Classification of chemicals for control of pollution

Protection of Nature. Soil. Nomenclature of sanitation indicators

Protection of Nature. Soil. General requirements for controlling and protection against pollution

GOST 26483-85 soil. Preparation of salt exhaust and determination of its pH according to the method of Zinao

GOST 26714-85 organic fertilizers. Method for determining ash

GOST 26715-85 organic fertilizers. Methods for determining the total nitrogen

GOST 26717-85 organic fertilizers. Methods for determining the common phosphorus

GOST R 8.563-96 State system for ensuring unity of measurements. Methods of measurement measurements

3 Definitions

This standard applies the following terms with the corresponding definitions.

sleeping sewage: Solid wastewater fraction consisting of organic and mineral substances isolated in the process of wastewater treatment with the method of settling (raw precipitate), and a complex of microorganisms participating in the process of biological wastewater treatment and derived from technological process (Excess Active IL).

precipitation products: Precipitation, processed by biotechnology (including composting), physical and chemical methods that meet the requirements of this standard and having a commodity view.

heavy metals: Group of metals with atomic weight of more than 50 (PB, CD, NI, CR, ZN, CU, HG ), which at certain concentrations can have a toxic effect.

4 Requirements for precipitation properties

4.1 The precipitation used as organic or complex organic fertilizers must comply with the requirements given in.

Table 1 - agrochemical precipitation indicators

Table 2 - permissible gross content of heavy metals and arsenic in precipitation

4.2 Sedips can be used as fertilizers with different moisture levels.

4.3 on the concentration of heavy metals and arsenic of precipitation during agricultural use are divided into two groups () based on the results of chemical analysis by methods in accordance with GOST R 8.563. If the content of at least one of the normalized elements exceeds its permissible level for group I, the precipitation is referred to group II.

4.3.1 Sighties of Group I use under all types of crops, except vegetable, mushrooms, green and strawberries.

4.3.2 Sighties of Group II are used for grain, leguminous, grainiforous and technical crops.

4.4 The precipitates of groups I and II are used in industrial flower growing, green construction, forest and ornamental nurseries, for biological reclamation of disturbed lands and polygons of MSW.

4.5 The dose of precipitation for agricultural crops in each case is calculated taking into account actual content normalized in precipitation and in the soil (on the sedimentation section) (). When making precipitation in the calculated doses, the quality of agricultural products has been required to comply with the requirements.

With a possible content of precipitated by the current standard of heavy metals and organic compounds, for which MPCs are developed in soils, the dose of precipitation is also calculated by software.

In the non-agricultural use of precipitation, the dose of application is determined by the technologies of cultivation of cultures and directions (technologies) of recultivation.

4.6 Cells can be used on soils and produced peatlands. The use of precipitation on soils, including undermined by sandy sediments and produced peatlands with a pH of less than 5.5, is preceded by their liming. The precipitates that have passed the processing stage using the lime are used as organic-discrete fertilizers of soils with a pH of less than 5.5 in doses, calculated based on the content of calcium in the accuracy of the precipitate.

4.7 precipitates in which the normalized indicators exceed the values \u200b\u200ballowed for group, but at the same time chemical composition Corresponds to the 4th class of hazards, can be used to restore the productivity of disturbed lands in order to limoity and recreational directions of their recultivation or are subject to accommodation on specially equipped polygons or TWW polygons.

4.9 The procedure for the use of precipitation as fertilizers is determined by the technological regulation, which is developing specialized organizations, taking into account regional and local conditions, including properties and hydrological regimes of soils, in precipitation and soil of normalized pollution, total and mineral nitrogen, phosphorus, potassium, and cultivation features crops adopted by crop rotation, etc.

5 Environmental Requirements

5.1 The use of precipitation as fertilizers should not lead to the deterioration of environmental and sanitary and hygienic indicators of the environment, soils grown by plants.

5.2. It is allowed to apply precipitation:

in water protection zones and zones of water bodies and their coastal protective bands, as well as within the limits of specially protected natural territories;

superficial in forests, forestarks, on hay and pastures;

on flooded and overwhelmed soils;

in areas with sharply crossed terrain, as well as on sites that have a bias toward a reservoir more than 3 °.

5.3 Quality control of precipitation provide analytical laboratories whose accreditation organizes and conducts a state standard of Russia and others federal bodies executive legislative acts Russian Federation This work is assigned within their competence.

5.4 When delivering precipitation to the consumer to the shipped by the batch, the supplier places a passport and a certificate of conformity, developed by the authority authorized for work in this area.

5.5 The procedure for monitoring the content in the soil and the grown agricultural and other products of normalized pollution and sanitary indicators is determined by the technological regulation.

Appendix A.
(mandatory)

Calculation of permissible doses of precipitation when using them as fertilizers for agricultural crops

A.1 General (total) dose of precipitation for the content (normalized) pollution D. common , T / ha dry substance, calculated by the formula

Maximum permissible sediment D. UD, T / ha dry matter, calculate according to the formula

(2)

Legend:

PDK - maximum permissible concentration of normed pollution in soil, mg / kg; In the absence of approved PDCs, approximately permissible concentration (CHD) contamination in the soil is used in the calculation., ];

F. - the actual contamination content in the soil, mg / kg;

from - pollution concentration in precipitation, mg / kg of dry matter;

t - Mass of the soil arable layer in terms of dry matter, t / ha.

A.2 Calculation is carried out according to each normed in or non-normalized contamination separately. From the data obtained, the minimum value is chosen, which determines the dose of a particular precipitate, taking into account the properties of the soil and its actual contamination.

The amount of mineral nitrogen introduced with a precipitate should not exceed its removal with crops.

The introduction of rolling phosphorus with precipitates is limited to the capacity of phosphate absorption with soils.

Appendix B.

Bibliography

7 Approximately permissible concentrations (ADC) of heavy metals and arsenic in soils: GN 2.1.7.020-94 (Supplement No. 1 to the List of MPC and CH No. 6229-91). Applied. GKS EN RF 27.12.94

Keywords: sewage precipitations, fertilizers, permissible content, heavy metals, deposit doses

The rationalization of heavy metals

in the soil and plants is extremely difficult due to the impossibility of full accounting of all factors of the natural environment. So, the change in only the agrochemical properties of the soil (reaction of the medium, the content of humus, the degree of saturation of the bases, the granulometric composition) can be reduced several times or increase the content of heavy metals in plants. There are conflicting data even about the background content of some metals. Researted results differ sometimes 5-10 times.

A variety of scales are proposed

environmental rationing of heavy metals. In some cases, for the maximum permissible concentration, the highest metal content observed in conventional anthropogenic soils, in the other content, which is limiting on phytotoxicity. In most cases, PDCs are proposed for heavy metals, superior to the upper rate several times.

For the characteristics of technogenic pollution

heavy metals use a concentration coefficient equal to the ratio of the concentration of the element in the contaminated soil to its background concentration. When contaminated with several heavy metals, the degree of pollution is estimated in size total indicator Concentration (ZC). The soil contamination scale proposed by the soil pollution scale is supervised in Table 1.

Table 1. Scheme of the assessment of the soils of agricultural use according to the degree of contamination by chemicals (USSR State Committee, No. 02-10 51-233 dated 10.12.90)

Officially approved PDK

Table 2 shows officially approved MPCs and permissible levels of their content in terms of harmfulness. In accordance with adopted by physician-hygienist scheme, the normalization of heavy metals in the soils is divided into a translocation (transition of an element in plants), a migrating aqueous (transition to water), and an unitnitious (effect on the self-cleaning capacity of soils and soil microbiocenosis).

Table 2. The maximum permissible concentrations (MPC) of chemicals in soils and permissible levels of their content in terms of harm indicators (as of 01/01/1991. State Committee of the USSR, No. 02-2333 dated 10.12.90).

* - Gross content - estimated.
** - contradiction; For arsenic, the average background content of 6 mg / kg, the background lead content usually exceeds the norms of the MPC.

Officially approved ADK

Developed in 1995, ADC for gross content of 6 heavy metals and arsenic makes it possible to obtain a more complete characteristic of soil contamination with heavy metals, as they take into account the level of the reaction of the medium and the granulometric composition of the soil.

Table 3. Approximately permissible concentrations (CHC) of heavy metals and arsenic in soils with various physicochemical properties (gross content, mg / kg) (Supplement No. 1 to the List of MPC and ADC No. 6229-91).

From materials it follows that mainly the requirements for gross forms of heavy metals are presented. Among the movable only copper, nickel, zinc, chrome and cobalt. Therefore, currently developed standards have no longer satisfy all the requirements.

it is a factor of a container reflecting primarily the potential danger of pollution of plant products, infiltration and surface waters. It characterizes the overall soil contamination, but does not reflect the degree of availability of elements for the plant. For the characteristics of the state of soil food of plants, only their mobile forms are used.

Definition of moving molds

They are determined using various extractants. The total amount of moving metal-applying acid hood (for example 1H HCl). The acetate-ammonium buffer passes the most mobile part of the moving stocks of heavy metals in the soil. The concentration of metals in the aqueous hood shows the degree of mobility of elements in the soil, being the most dangerous and "aggressive" fraction.

Standards for moving forms

Several approximate regulatory scales are proposed. Below is an example of one of the scales of maximum permissible movable forms of heavy metals.

Table 4. Maximum allowable content of the movable shape of heavy metals in the soil, mg / kg Extractant 1H. HCl (H. Chuldzhyan et al., 1988).