Increased manganese content in well water. Manganese contamination of water. Maximum permissible concentration of tin for the aquatic environment
I would like to clarify right away what “increased content” is. Water from a well or wells, as well as from other sources, is used for various purposes: technical needs, drinking, etc. In most cases, we are all interested in the question of whether water is safe to drink. In order to be able to easily answer this question, having before our eyes a chemical analysis protocol, we need to know the maximum permissible concentrations (MAC) of a particular component. These values for drinking water are regulated in SanPiN 2.1.4.1074-01. That is, by comparing the results of the analysis with the maximum permissible concentrations given in this SanPiN 2.1.4.1074-01, we can understand whether the water is safe to drink or not. In order for you not to look for this data and not sit and meticulously compare, our analysis protocol already has a column containing MPC indicators from SanPin and there is a conclusion whether the water complies with SanPin or not.
Why is it dangerous...
Iron
Maximum permissible concentration of iron (Fe) in drinking water- 0.3 mg/l.
Effect on plumbing: Increased iron content in water is one of the main causes of biofouling of water pipes. According to recent studies, the source of mucus that forms on the connecting and joint elements of the pipeline is iron bacteria. Over time, biofouling can lead to damage and corrosion of plumbing fixtures.
Effect on the body: Iron often causes the development of dermatitis, allergic reactions, liver and kidney diseases. It is believed that exceeding the maximum permissible concentration of iron in water increases the risk of heart attacks and tissue damage during strokes. Few people know that in the presence of oxygen, iron exhibits carcinogenic properties. The fact is that it is hydroxide free radicals that cause DNA mutation and the subsequent development of cancer cells. As soon as the mechanism of formation of a malignant tumor starts, damaged cells begin to look for iron to replenish.
How to reduce iron content: The simplest and most budget method deferrization of water: Find a storage tank of sufficient size made of food-grade plastic, stainless steel, etc. Install it in suitable place, for example on the roof. Organize the supply of water from the well through a shower diffuser (this improves water aeration). Ensure that the settled water is not taken from the very bottom of the tank, but slightly higher, so that sediment does not fall into the water supply. It is optimal if the dimensions of the storage tank exceed daily consumption water. This allows you to collect water in the evening and use it freely throughout the day. The second method, but not as budgetary, is the use of cleaning systems.
Manganese
The maximum permissible concentration of manganese (Mn) in drinking water is 0.1 mg/l.
Effect on plumbing: As a result of the increased content of manganese in water, deposits of this metal begin to accumulate on the internal surfaces of water pipes and water heating equipment, which, in turn, can cause blockage and deterioration of heat transfer processes. In addition, such water leaves indelible marks on plumbing fixtures.
Effect on the body: Recent studies have shown that drinking water excessively enriched with manganese leads to a decrease in intellectual abilities in children. Constant consumption of drinking water in which the concentration of manganese exceeds 0.1 mg/l can provoke the occurrence of serious diseases of the skeletal system. Manganese accumulates in the human body and is almost impossible to remove. Manganese penetrates the tubules of nerve cells and thereby prevents the passage of nerve impulses. Also, an increased content of manganese in drinking water threatens liver diseases, where this metal is mainly concentrated. In addition, manganese, consumed together with water, has the ability to penetrate the small intestine, bones, kidneys, endocrine glands and even affect the brain.
How to reduce manganese content: special water treatment systems.
Rigidity
The maximum permissible concentration of hardness in drinking water is 7 mmol.
Effect on plumbing: When hard water interacts with detergents ( washing powders, soap, shampoos) “soap slag” appears, which looks like foam. After drying, this foam remains in the form of a coating on the skin, hair, linen, and plumbing fixtures. The negative effect of such wastes on the human body is manifested by the fact that they begin to destroy the natural fatty film that covers the skin and clog pores. Effect on the body: The World Health Organization (WHO) has not established any hardness value based on the impact on the human body. Although research has found inverse relationship between water hardness and cardiovascular diseases, these data are insufficient to make a definitive conclusion. It has also not been proven that too soft water can have a negative effect on the balance of minerals in the body. However, high hardness makes water worse, gives it a bitter taste, has a negative effect on the digestive organs, the water-salt balance in the body is disturbed, and various allergic reactions can occur.
How to reduce hardness: Boil water to remove temporary hardness. Use the ice freezing method. It is often used when water is constantly hard. Gradually freeze the water. When you find that approximately 10% of the original volume remains, drain the unfrozen water and melt the ice. The fact is that all the salts that impart hardness remain in unfrozen water. Install water purification filters.
Nitrates, nitrites
The maximum permissible concentration of nitrates (NO3) and nitrites (NO2) is 45 mg/l and 3.0 mg/l, respectively.
Impact on plumbing: -
Effect on the body: It is not nitrates that are dangerous, it is nitrites and nitrate breakdown products - free radicals that have a carcinogenic and mutagenic effect. Nitrates are converted to nitrites during digestion and even in the mouth. Nitrites, entering the blood, “kill” hemoglobin. Hemoglobin is a carrier of oxygen. “Damaged” hemoglobin (methemoglobin) is not able to carry oxygen, which leads to oxygen starvation of cells, liver function is disrupted, and general poisoning of the body occurs. In water from wells located near agricultural lands, a nitrate content of more than 100 mg/l is observed. Such water without purification can become one of the factors influencing direct influence for life expectancy. The lethal dose of nitrates for humans is 8-15 g.
How to reduce the content of nitrites and nitrates: special water treatment systems. It is very important not to become the source of nitrates in the water; to do this, keep cesspools and septic tanks as far as possible from the well (well).
Sulfates
The maximum permissible concentration of sulfates in drinking water is 500 mg/l
Effect on plumbing: Sulfates can form scale. When using lead pipes, sulfate concentrations above 200 mg/l can lead to lead leaching into the water.
Effect on the body: High levels of sulfates worsen the organoleptic properties of water and have physiological effects on the human body - they have laxative properties.
How to reduce the content: To get rid of excess sulfates in water, you need to install a reverse osmosis system.
Chlorides
The maximum permissible concentration of chlorine in drinking water is 350 mg/l.
Impact on plumbing: -
Effect on the body: affects water-salt metabolism; the level of chlorides in the blood increases, which leads to a decrease in diuresis and redistribution of chlorides in organs and tissues; cause inhibition of gastric secretion, as a result of which the process of food digestion is disrupted; there is evidence that chlorides have a hypertensive effect in people suffering from hypertension drinking water with illness increased content chlorides can cause aggravation of the disease;
How to reduce content: Set aside water in open containers
Dry residue or mineralization
The maximum permissible concentration of dry residue in drinking water is 1000 mg/l.
Impact on plumbing: -
Effect on the body: a) promotes overheating in hot weather, b) leads to impaired thirst quenching, c) changes water-salt metabolism by increasing the hydrophilicity of tissues, d) enhances the motor and secretory functions of the stomach and intestines.
How to reduce content: special water treatment systems.
Heavy metals are very dangerous toxic substances. Nowadays, monitoring the levels of various such substances is especially important in industrial and urban areas.
Although everyone knows what heavy metals are, not everyone knows which chemical elements are included in this category. There are many criteria by which different scientists determine heavy metals: toxicity, density, atomic mass, biochemical and geochemical cycles, distribution in nature. According to one criteria, heavy metals include arsenic (a metalloid) and bismuth (a brittle metal).
General facts about heavy metals
More than 40 elements are known that are classified as heavy metals. They have an atomic mass greater than 50 au. Oddly enough, these elements are highly toxic even with low accumulation for living organisms. V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo...Pb, Hg, U, Th...all fall into this category. Even with their toxicity, many of them are important trace elements, except for cadmium, mercury, lead and bismuth for which no biological role has been found.
According to another classification (namely N. Reimers), heavy metals are elements that have a density greater than 8 g/cm 3 . This way you will get fewer of the following elements: Pb, Zn, Bi, Sn, Cd, Cu, Ni, Co, Sb.
Theoretically, the entire periodic table of elements, starting with vanadium, can be called heavy metals, but researchers prove to us that this is not entirely true. This theory is due to the fact that not all of them are present in nature within toxic limits, and the confusion in biological processes for many is minimal. This is why many people only include lead, mercury, cadmium and arsenic in this category. The UN Economic Commission for Europe does not agree with this opinion and believes that heavy metals are zinc, arsenic, selenium and antimony. The same N. Reimers believes that by removing rare and noble elements from the periodic table, heavy metals remain. But this is also not a rule; others add gold, platinum, silver, tungsten, iron, and manganese to this class. That’s why I’m telling you that not everything is clear on this topic...
Discussing the balance of ions of various substances in solution, we will find that the solubility of such particles is associated with many factors. The main factors of solubilization are pH, the presence of ligands in solution and redox potential. They are involved in the oxidation processes of these elements from one oxidation state to another, in which the solubility of the ion in solution is higher.
Depending on the nature of the ions, various processes can occur in the solution:
- hydrolysis,
- complexation with different ligands;
- hydrolytic polymerization.
Due to these processes, ions can precipitate or remain stable in solution. The catalytic properties of a certain element and its availability to living organisms depend on this.
Many heavy metals form fairly stable complexes with organic substances. These complexes are part of the mechanism of migration of these elements in ponds. Almost all chelate complexes of heavy metals are stable in solution. Also, complexes of soil acids with salts of various metals (molybdenum, copper, uranium, aluminum, iron, titanium, vanadium) have good solubility in neutral, slightly alkaline and slightly acidic environments. This fact is very important, because such complexes can move in a dissolved state over long distances. Most susceptible water resources- These are low-mineralized and surface water bodies where the formation of other such complexes does not occur. To understand the factors that regulate the level of a chemical element in rivers and lakes, their chemical reactivity, bioavailability and toxicity, it is necessary to know not only the total content, but also the proportion of free and related forms metal
As a result of the migration of heavy metals into metal complexes in solution, the following consequences can occur:
- Firstly, the cumulation of ions of a chemical element increases due to the transition of these from bottom sediments into natural solutions;
- Secondly, the possibility arises of changing the membrane permeability of the resulting complexes, in contrast to ordinary ions;
- Also, the toxicity of an element in a complex form may differ from the usual ionic form.
For example, cadmium, mercury and copper in chelated forms have less toxicity than free ions. That is why it is not correct to talk about toxicity, bioavailability, chemical reactivity only according to general content of a certain element, without taking into account the proportion of free and bound forms of a chemical element.
Where do heavy metals come from in our environment? The reasons for the presence of such elements may be wastewater from various industrial facilities involved in ferrous and non-ferrous metallurgy, mechanical engineering, and galvanization. Some chemicals are found in pesticides and fertilizers and thus can pollute local ponds.
And if you go into the secrets of chemistry, the main culprit in increasing the level of soluble salts of heavy metals is acid rain (acidification). A decrease in the acidity of the environment (decrease in pH) entails the transition of heavy metals from poorly soluble compounds (hydroxides, carbonates, sulfates) to more readily soluble ones (nitrates, hydrosulfates, nitrites, bicarbonates, chlorides) in the soil solution.
Vanadium (V)
It should be noted first of all that contamination with this element in natural ways unlikely because this element is very dispersed in the Earth's crust. Found in nature in asphalts, bitumens, coals, iron ores Oh. Oil is an important source of pollution.
Vanadium content in natural reservoirs
Natural bodies of water contain a negligible amount of vanadium:
- in rivers - 0.2 - 4.5 µg/l,
- in the seas (on average) - 2 µg/l.
In the processes of transition of vanadium in the dissolved state, the anionic complexes (V 10 O 26) 6- and (V 4 O 12) 4- are very important. Also very important are soluble vanadium complexes with organic substances, such as humic acids.
Maximum permissible concentration of vanadium for the aquatic environment
Vanadium in high doses is very harmful to humans. The maximum permissible concentration for the aquatic environment (MPC) is 0.1 mg/l, and in fishery ponds, the MAC for fish farms is even lower - 0.001 mg/l.
Bismuth (Bi)
Mainly, bismuth can enter rivers and lakes as a result of leaching processes of minerals containing bismuth. There are also man-made sources of pollution with this element. These could be glass, perfume and pharmaceutical factories.
Bismuth content in natural reservoirs
- Rivers and lakes contain less than a microgram of bismuth per liter.
- But groundwater can contain even 20 µg/l.
- In the seas, bismuth usually does not exceed 0.02 μg/l.
Maximum permissible concentration of bismuth for the aquatic environment
The maximum permissible concentration of bismuth for the aquatic environment is 0.1 mg/l.
Iron (Fe)
Iron - chemical element It 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 processes of weathering of rocks, destruction of these rocks and dissolution. Forming various complexes with organic substances from solution, iron can be in colloidal, dissolved and suspended states. It is impossible not to mention anthropogenic sources of iron pollution. Wastewater from metallurgical, metalworking, paint and varnish and textile factories sometimes goes off scale due to excess iron.
The amount of iron in rivers and lakes depends on chemical composition solution, pH and partly on temperature. Suspended forms of iron compounds are larger than 0.45 µg. The main substances that make up these particles are suspensions with sorbed iron compounds, iron oxide hydrate and other iron-containing minerals. Smaller particles, that is, colloidal forms of iron, are considered together with dissolved iron compounds. Iron in a dissolved state consists of ions, hydroxo complexes and complexes. Depending on the valency, it is noted that Fe(II) migrates in ionic form, and Fe(III) in the absence of various complexes remains in a dissolved state.
In the balance of iron compounds in aqueous solution, the role of oxidation processes, both chemical and biochemical (iron bacteria), is also very important. These bacteria are responsible for the transition of iron ions Fe(II) to the Fe(III) state. Ferric compounds tend to hydrolyze and precipitate Fe(OH) 3 . Both Fe(II) and Fe(III) are prone to the formation of hydroxo complexes of the type - , + , 3+ , 4+ , + , depending on the acidity of the solution. IN normal conditions in rivers and lakes, Fe(III) is found in association with various dissolved inorganic and organic substances. At pH greater than 8, Fe(III) transforms into Fe(OH)3. Colloidal forms of iron compounds are the least studied.
Iron content in natural reservoirs
In rivers and lakes, iron levels fluctuate at n*0.1 mg/l, but can increase to several mg/l near swamps. In swamps, iron is concentrated in the form of humate salts (salts of humic acids).
Underground reservoirs with low pH contain record amounts of iron - up to several hundred milligrams per liter.
Iron is an important trace element and various important biological processes depend on it. It affects the intensity of phytoplankton development and the quality of microflora in water bodies depends on it.
The level of iron in rivers and lakes is seasonal. The highest concentrations in reservoirs are observed in winter and summer due to water stagnation, but in spring and autumn the level of this element noticeably decreases due to mixing of water masses.
Thus, a large amount of oxygen leads to the oxidation of iron from a divalent form to a trivalent one, forming iron hydroxide, which precipitates.
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 poor taste. It has an unpleasant astringent taste and is unsuitable for industrial purposes.
The maximum permissible concentration of iron for the aquatic environment is 0.3 mg/l, and in fishery ponds the maximum permissible concentration for fish farms is 0.1 mg/l.
Cadmium (Cd)
Cadmium contamination can occur during soil leaching, during the decomposition of various microorganisms that accumulate it, as well as due to migration from copper and polymetallic ores.
Humans are also to blame for pollution with this metal. Wastewater from various enterprises involved in ore processing, galvanic, chemical, and 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 precipitation of poorly soluble cadmium carbonate.
In solution, cadmium is usually found in the form of organo-mineral and mineral complexes. Sorbed substances based on cadmium are the most important suspended forms of this element. The migration of cadmium into living organisms (hydrobionites) is very important.
Cadmium content in natural reservoirs
The level of cadmium in clean rivers and lakes fluctuates at levels of less than a microgram per liter; in polluted waters the level of this element reaches several micrograms per liter.
Some researchers believe that cadmium, in small quantities, may be important for the normal development of animals and humans. Elevated concentrations of cadmium are very dangerous for living organisms.
Maximum permissible concentration of cadmium for the aquatic environment
The maximum permissible concentration for the aquatic environment does not exceed 1 µg/l, and in fishery ponds the maximum permissible concentration for fish farms is less than 0.5 µg/l.
Cobalt (Co)
Rivers and lakes can become contaminated with cobalt as a result of the leaching of copper and other ores from soils 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 conditions 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 characteristic that cobalt is a divalent cation. In the presence of a large number of oxidizing agents in solution, cobalt can be oxidized to a trivalent cation.
It is found in plants and animals because it plays important role in their development. Included in the number of essential microelements. If there is a deficiency of cobalt in the soil, then its level in plants will be lower than usual and, as a result, health problems may arise in animals (there is a risk of anemia). This fact is observed especially in the taiga-forest non-chernozem 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 grow required amount squirrel. Like all heavy metals, it can be toxic large quantities.
Cobalt content in natural reservoirs
- Cobalt levels in rivers vary from a few micrograms to milligrams per liter.
- In the seas, the average level of cadmium is 0.5 μg/l.
Maximum permissible concentration of cobalt for the aquatic environment
The maximum permissible concentration of cobalt for the aquatic environment is 0.1 mg/l, and in fishery ponds the maximum permissible concentration for fish farms is 0.01 mg/l.
Manganese (Mn)
Manganese enters rivers and lakes through the same mechanisms as iron. Mainly, the release of this element in solution occurs during the leaching of minerals and ores that contain manganese (black ocher, brownite, pyrolusite, psilomelane). Manganese can also come from the decomposition of various organisms. Industry, I think, plays the largest role in manganese pollution (mine wastewater, chemical industry, metallurgy).
A decrease in the amount of assimilable metal in solution occurs, as is the case with other metals under aerobic conditions. Mn(II) is oxidized to Mn(IV), as a result of which it precipitates in the form of MnO 2. Important factors in such processes are temperature, the amount of dissolved oxygen in the solution and pH. A decrease in dissolved manganese in the solution can occur when it is consumed by algae.
Manganese migrates mainly in the form of suspension, which, as a rule, indicates the composition of the surrounding rocks. They contain it as a mixture with other metals in the form of hydroxides. The predominance of manganese in colloidal and dissolved forms suggests that it is associated with organic compounds forming complexes. Stable complexes are seen with sulfates and bicarbonates. With chlorine, manganese forms complexes less frequently. Unlike other metals, it is less retained in complexes. Trivalent manganese forms such compounds only in the presence of aggressive ligands. Other ionic forms (Mn 4+, Mn 7+) are less rare or not found at all under normal conditions in rivers and lakes.
Manganese content in natural reservoirs
The seas are considered the poorest in manganese - 2 µg/l, in rivers its content is higher - up to 160 µg/l, but underground reservoirs are record holders this time too - from 100 µg to several mg/l.
Manganese is characterized by seasonal fluctuations in concentration, like iron.
Many factors have been identified that influence the level of free manganese in solution: the connection of rivers and lakes with underground reservoirs, the presence of photosynthetic organisms, aerobic conditions, decomposition of biomass (dead organisms and plants).
An important biochemical role of this element is because it is part of the group of microelements. Many processes are inhibited due to manganese deficiency. It increases the intensity of photosynthesis, participates in nitrogen metabolism, protects cells from negative impact Fe(II) while oxidizing it into the trivalent form.
Maximum permissible concentration of manganese for the aquatic environment
The maximum permissible concentration of manganese for reservoirs is 0.1 mg/l.
Copper (Cu)
Not a single microelement has such an important role for living organisms! Copper is one of the most sought-after microelements. It is part of many enzymes. Without it, almost nothing works in a living organism: the synthesis of proteins, vitamins and fats is disrupted. Without it, plants cannot reproduce. Still, an excess amount of copper causes severe intoxication in all types of living organisms.
Copper levels in natural reservoirs
Although copper has two ionic forms, the one most commonly found in solution is Cu(II). Typically, Cu(I) compounds are poorly soluble in solution (Cu 2 S, CuCl, Cu 2 O). Different copper aquaions can arise in the presence of various ligands.
With today's high use of copper in industry and agriculture, this metal can cause pollution environment. Chemical and metallurgical plants and mines can be sources of wastewater with a high copper content. Pipeline erosion processes also contribute to copper contamination. The most important minerals with a high copper content are malachite, bornite, chalcopyrite, chalcocite, azurite, and bronzantine.
Maximum permissible concentration of copper for the aquatic environment
The MPC of copper for the aquatic environment is considered to be 0.1 mg/l; in fishery ponds, the MPC of copper in fisheries is reduced to 0.001 mg/l.
Molybdenum (Mo)
During the leaching of high molybdenum minerals, various molybdenum compounds are released. High levels of molybdenum can be seen in rivers and lakes that are located near enrichment factories and non-ferrous metallurgy enterprises. Due to different processes of precipitation of sparingly soluble compounds, adsorption on the surface different breeds, as well as consumption of aquatic algae and plants, its amount may decrease noticeably.
Mostly in solution, molybdenum can be in the form of the MoO 4 2- anion. There is a possibility of the presence of organomolybdenum complexes. Due to the fact that loose, finely dispersed compounds are formed during the oxidation of molybdenite, the level of colloidal molybdenum increases.
Molybdenum content in natural reservoirs
Molybdenum levels in rivers range 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 (both plant and animal), because it is included in the category of microelements. He is also integral part various enzymes such as xanthine oxygenlases. With a lack of molybdenum, a deficiency of this enzyme occurs and thus negative effects can occur. An excess of this element is also not welcome, because normal metabolism is disrupted.
Maximum permissible concentration of molybdenum for the aquatic environment
MPC of molybdenum surface waters oyomah should not exceed 0.25 mg/l.
Arsenic (As)
Contaminated with arsenic are mainly areas that are close to mineral mines with a high content of this element (tungsten, copper-cobalt, polymetallic ores). Very small amounts of arsenic can occur during the decomposition of living organisms. Thanks to aquatic organisms, it can be absorbed by these. Intensive absorption of arsenic from solution is observed during the period of rapid development of plankton.
The most important arsenic pollutants are the processing industry, enterprises producing pesticides, dyes, and agriculture.
Lakes and rivers contain arsenic in two states: 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 pentavalent, occurring in anionic forms.
Arsenic levels in natural water bodies
In rivers, as a rule, the arsenic content is very low (at the level of µg/l), and in the seas - on average 3 µg/l. Some mineral waters may contain large amounts of arsenic (up to several milligrams per liter).
Most arsenic can be found in underground reservoirs - up to several tens of milligrams per liter.
Its compounds are very toxic to all animals and humans. In large quantities, oxidation processes and oxygen transport to cells are disrupted.
Maximum permissible concentration of arsenic for the aquatic environment
The maximum permissible concentration of arsenic for the aquatic environment is 50 µg/l, and in fishery ponds the maximum permissible concentration for fish farms is also 50 µg/l.
Nickel (Ni)
Local rocks influence the nickel content of lakes and rivers. If there are deposits of nickel and iron-nickel ores near the reservoir, the concentrations may be even higher than normal. Nickel can enter lakes and rivers through decomposition of plants and animals. Blue-green algae contain record amounts of nickel compared to other plant organisms. Important waste waters with high nickel content are released during production synthetic rubber, during nickel plating processes. Nickel is also released in large quantities during the combustion of coal and oil.
High pH may cause nickel to precipitate in the form of sulfates, cyanides, carbonates or hydroxides. Living organisms can reduce the level of mobile nickel by consuming it. Adsorption processes on the surface of rocks are also important.
Water can contain nickel in dissolved, colloidal and suspended forms (the balance between these states depends on the pH of the environment, temperature and composition of the water). Iron hydroxide, calcium carbonate, and clay absorb nickel-containing compounds well. Dissolved nickel is found in the form of complexes with fulvic and humic acids, as well as with amino acids and cyanides. Ni 2+ is considered the most stable ionic form. Ni 3+, as a rule, is formed at high pH.
In the mid-50s, nickel was included in the list of trace elements because it plays an important role in various 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 various diseases of the respiratory system. Free Ni 2+ is more toxic than in the form of complexes (about 2 times).
Nickel levels in natural reservoirs
Maximum permissible concentration of nickel for the aquatic environment
The maximum permissible concentration of nickel for the aquatic environment is 0.1 mg/l, but in fishery ponds the maximum permissible concentration for fish farms is 0.01 mg/l.
Tin (Sn)
Natural sources of tin are minerals that contain this element (stannine, cassiterite). Anthropogenic sources are considered to be plants and factories producing various organic paints and the metallurgical industry working with the addition of tin.
Tin is a low-toxic metal, which is why we do not risk our health by eating food from metal cans.
Lakes and rivers contain less than a microgram of tin per liter of water. Underground reservoirs may contain several micrograms of tin per liter.
Maximum permissible concentration of tin for the aquatic environment
The maximum permissible concentration of tin for the aquatic environment is 2 mg/l.
Mercury (Hg)
Mainly, increased levels of mercury in water are noticed in areas where there are mercury deposits. The most common minerals are livingstonite, cinnabar, and metacinnabarite. Wastewater from factories producing various drugs, pesticides, and dyes may contain important amounts of mercury. Another important source of mercury pollution is thermal power plants (which use coal as fuel).
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 life rises several times higher than in the marine environment.
Natural water contains mercury in two forms: suspended (in the form of sorbed compounds) and dissolved (complex, mineral mercury compounds). In certain areas of the oceans, mercury can appear in the form of methylmercury complexes.
Mercury and its compounds are very toxic. At high concentrations, it has a negative effect on the nervous system, provokes changes in the blood, affects the secretion of the digestive tract and motor function. The products of mercury processing by bacteria are very dangerous. They can synthesize organic substances based on mercury, which are many times more toxic than inorganic compounds. When eating fish, mercury compounds can enter our body.
Maximum permissible concentration of mercury for the aquatic environment
The maximum permissible concentration of mercury in ordinary water is 0.5 µg/l, and in fishery ponds the maximum permissible concentration for fish farms is less than 0.1 µg/l.
Lead (Pb)
Rivers and lakes can be polluted with lead naturally when lead minerals are washed away (galena, anglesite, cerussite), and through anthropogenic means (coal combustion, the use of tetraethyl lead in fuel, discharges from ore processing factories, wastewater from mines and metallurgical plants). The deposition of lead compounds and the adsorption of these substances on the surface of various rocks are the most important natural methods decreasing its level in solution. Of the biological factors, hydrobionts lead to a decrease in the level of lead in the solution.
Lead in rivers and lakes is in suspended and dissolved forms (mineral and organomineral complexes). Lead is also found in the form of insoluble substances: sulfates, carbonates, sulfides.
Lead content in natural reservoirs
We have heard a lot about the toxicity of this heavy metal. It is very dangerous even in small quantities and can cause intoxication. Lead enters the body through the respiratory and digestive systems. Its release from the body is very slow, and it can accumulate in the kidneys, bones and liver.
Maximum permissible concentration of lead for the aquatic environment
The maximum permissible concentration of lead for the aquatic environment is 0.03 mg/l, and in fishery ponds the maximum permissible concentration for fish farms is 0.1 mg/l.
Tetraethyl lead
It serves as an anti-knock agent in motor fuel. Thus, the main sources of pollution with this substance are vehicles.
This compound is very toxic and can accumulate in the body.
Maximum permissible concentration of tetraethyl lead for the aquatic environment
The maximum permissible level of this substance is approaching zero.
Tetraethyl lead is generally not allowed in water.
Silver (Ag)
Silver mainly enters rivers and lakes from underground reservoirs and as a result of wastewater discharges from enterprises (photography enterprises, enrichment factories) and mines. Another source of silver can be algaecides and bactericides.
In solution, the most important connections are silver halide salts.
Silver content in natural reservoirs
In clean rivers and lakes, the silver content is less than a microgram per liter, in the seas it is 0.3 µg/l. Underground reservoirs contain up to several tens of 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 not yet well known.
Maximum permissible concentration of silver for the aquatic environment
The maximum permissible silver for the aquatic environment is 0.05 mg/l.
Manganese in the blood
Determination of manganese concentration in the blood, used to diagnose acute and chronic manganese intoxication, as well as to assess the balance of this trace element in the body.
Synonyms Russian
Manganese in blood serum.
English synonyms
Mn, Manganese, Serum.
Research method
Atomic adsorption spectrometry (AAS).
Units
μg/L (micrograms per liter).
What biomaterial can be used for research?
Venous blood.
How to properly prepare for research?
- Do not eat for 2-3 hours before the test; you can drink clean still water.
- Do not smoke for 30 minutes before the test.
General information about the study
Manganese is an element found in free form in living nature, and is also part of some organic and inorganic compounds of the human body. It is necessary for the formation of bone tissue, the synthesis of proteins, ATP molecules and the regulation of cellular metabolism. In addition, manganese acts as a cofactor for one of the varieties of superoxide dismutase (manganese), which neutralizes free radicals, and gluconeogenesis enzymes.
This microelement enters the body with food. It is present in large quantities in hazelnuts and walnuts, peanuts, spinach, beets, garlic, apricots and some other foods. The daily requirement of an adult for manganese is 1.8-2.6 mg. Normally, only 1-3% of manganese supplied with food is absorbed in the intestine, while the majority is excreted in the feces. As with other microelements, the concentration of manganese is maintained at a very low level, but sufficient to ensure physiological functions. Disturbances in its balance can be acute or chronic and are diagnosed using a test for manganese in the blood.
Food poisoning from manganese salts is extremely rare, since usually only a small part of it is absorbed in the intestine. The vast majority of cases of poisoning are examples of chronic intoxication associated with inhalation of manganese dust. Workers involved in ore mining and steel production are most at risk. The extensive surface of the lungs ensures the rapid absorption of manganese into the blood, from where it enters various organs. Deposition of manganese in brain tissue is accompanied by the development of a characteristic clinical syndrome called manganese parkinsonism. Its signs include gait disturbance, mask-like face, dystonia, and drooling. Unlike idiopathic parkinsonism, this form does not have resting tremor, but postural and intention tremor can be observed. Differential diagnosis of idiopathic and manganese parkinsonism is mandatory, since the diseases have different prognosis and are treated differently. The peculiarity of manganese parkinsonism is the lack of response to treatment with dopamine drugs and the irreversibility of changes. An analysis for manganese in the blood allows you to differentiate these two conditions.
Also, assessing the level of manganese in the blood may be necessary when examining a young patient with signs of atypical parkinsonism. Some people who use and independently produce injection drugs use potassium permanganate as an oxidizing agent, which enters the blood along with the narcotic substance. As a result, the concentration of manganese in such patients can be 2000-3000 mg/l (for comparison, the norm is 10-12 mg/l). Persistent increases in manganese levels damage neurons in the substantia nigra of the midbrain, leading to characteristic symptoms. The clinical picture of manganese parkinsonism can also be observed in patients with liver diseases - it is the main organ that ensures the removal of manganese from the body. With cirrhosis of the liver, the excretion of this element is difficult, as a result of which it accumulates in the blood and brain tissue.
It is believed that due to certain physiological characteristics, children are more at risk of both enteral and inhalational manganese poisoning. For example, drinking water with a high concentration of manganese salts is more important in the development of the disease in children than in adults. In addition, the clinical manifestations of chronic manganese intoxication in children also differ from those in adults. Manganese renders Negative influence on the transmission of nerve impulses in dopaminergic pathways that provide attention, coordination and cognitive activity. Therefore, it is advisable to measure its blood level when examining a child with attention deficit hyperactivity disorder and learning disabilities.
Inhalation of manganese vapor can also lead to the development of so-called metal fever. This condition develops 3-12 hours after inhalation of manganese oxide vapor and is more often observed in welders. The clinical picture of the disease resembles the flu: fever, cough, sore throat, feeling of nasal congestion, shortness of breath, weakness, myalgia. The peculiarity of “metal fever” is that all symptoms disappear after stopping contact with metal vapors (for example, on weekends). When testing the blood of such patients, it is sometimes possible to detect an increase in manganese concentration. It should be noted that the symptoms of “metal fever” are not specific to acute manganese poisoning and are also observed when inhaling vapors of zinc oxide, copper, iron, lead and other metals. Thus, analysis for manganese, as well as other metals in the blood, can be used in the diagnosis of occupational diseases.
Manganese deficiency is accompanied by some rare congenital metabolic diseases. More often, its deficiency occurs in patients long time on parenteral nutrition. Signs of manganese deficiency: impaired growth and mineralization of bones, metabolism of carbohydrates and fats. Measuring the concentration of manganese in the blood of such patients is necessary to assess the balance of this trace element in the body.
What is the research used for?
- To diagnose “metal fever” in a welder.
- For the diagnosis of manganese parkinsonism in mining workers, young people who inject drugs and patients with cirrhosis.
- For the diagnosis of chronic manganese intoxication in children with attention deficit disorder, hyperactive children and children with learning disabilities.
- To assess the balance of manganese in the body in a patient on total parenteral nutrition.
When is the study scheduled?
- For symptoms:
- parkinsonism, especially in mining workers, young people who inject drugs, and patients with cirrhosis (impaired gait and balance, “mask-like” face, dystonia, postural and intention tremor);
- flu-like syndrome in welders (fever, cough, sore throat, feeling of nasal congestion, shortness of breath, weakness, myalgia);
- attention deficit hyperactivity disorder in children (impossibility of concentrating, easy distraction by external stimuli - toys, writing materials, inability to complete exercises, wait for one's turn in games, butting into a conversation, shouting from one's seat).
- When monitoring a patient on total parenteral nutrition.
What do the results mean?
Reference values: 0 - 2 µg/l.
Reasons for increased manganese levels in the blood:
- acute or chronic manganese poisoning;
- cirrhosis of the liver.
The prevalence of manganese is quite high, it ranks 14th among commonly occurring minerals. It is present in many products and naturally in water, since it dissolves well. And, like any element that comes into food, it can be beneficial or harmful. So, purifying water from manganese and keeping it at a satisfactory level becomes highly important. 
GOST: manganese in drinking water
- V centralized systems– ≤ 0.1 mg/l;
- manganese in water from wells and other open sources – ≤ 0.5 mg/l.
In nature, manganese can form up to 8 types of oxides, from MnO to Mn5O8, and is part of copper and iron ores. The formation of oxides depends on the composition of the medium and external physical parameters. The most stable oxide is MnO2, which is also the most common in the bowels of the earth, and is called pyrolusite. 
In view of wide application mineral in metallurgy and chemical production, special attention is paid to its content in industrial wastewater. The amount of manganese in wastewater should not exceed 0.01 mg/dm3.
Manganese in water: effect on the body and visual determination of its presence
As is known from medical practice, even a toxic substance, in a small amount, can have a beneficial effect on the body, but exceeding its norm will lead to irreparable consequences.
Beneficial functions of manganese in the body
Depending on age, permissible daily doses vary and are:
Manganese can be obtained from both water and food. The territory of Russia does not have areas with poor Mn content; there is even an excess of manganese in the water. The participation of the mineral in the physiological processes of living organisms is irreplaceable. Its main functions:
- adjusting glucose levels, inducing the synthesis of ascorbic acid;
- inhibiting the development of diabetes mellitus;
- activity support nervous system and brain;
- production of cholesterol and assistance in the functioning of the pancreas;
- formation of connective, cartilage and bone tissue;
- regulation of lipid metabolism and prevention of fatty liver;
- involvement in cell division and renewal;
- inhibiting the activity of cholesterol and preventing the growth of “plaques”;
- activation of enzymes for the body to absorb vitamins B1, C and biotin.
Can be used as an antioxidant when interacting with Fe and Cu. Manganese is retained in the body by P and Ca. Eating foods high in carbohydrates leads to rapid depletion of Mn reserves in the body. The amount of manganese in water can have both positive and negative effects. In some conditions, a deficiency of manganese occurs; the norm in water does not cover its daily requirement for nursing mothers and athletes.
Harm from excess manganese in water
What is dangerous about manganese in water for physiological functions is that it reduces the absorption of iron and competes with copper, which results in anemia and drowsiness. Considerable harm is also caused to the central nervous system, expressed in decreased performance and the development of early amnesia. The heavy metal Mn can damage the lungs, liver and heart in large doses, and stop lactation in nursing women.
Health is one of the main aspirations of a person, but everyday problems created by manganese compounds can be quite annoying. Visual determination of manganese in drinking water is carried out by inspecting plumbing fixtures and utensils that are in long-term contact with tap liquid. 
Most often, the mineral accompanies divalent iron and forms insoluble compounds with it. Black deposits form on plumbing fixtures and food utensils, scale quickly builds up in electrical appliances, and the permeability of pipes decreases. Too much high level contamination is visible already when drawing water from the tap, and can even be tasted and smelled. In these cases, it is necessary to immediately do a water analysis; manganese and iron should be the main parameters studied.
Water purification from iron and manganese
In tap or artesian water, the mineral is found in the form of a divalent positive ion (Mn2 +), which is highly soluble in liquids. To remove manganese from water, it is converted into insoluble forms - trivalent or tetravalent. Dense sediment is removed with granular catalytic media or ion exchange resins.
Manganese water filters and filtration methods
Methods used in demanganation:
Aeration. It is used when there is divalent iron in the water. Under the influence of aeration, iron oxidizes and turns into hydroxide. The resulting compound binds divalent manganese and precipitates it. Solid impurities are filtered through quartz sand.
Catalytic oxidation. It is carried out with 4-valent manganese hydroxide.
Oxidizing reagents. Ozone, sodium hypochlorite, chlorine itself and its dioxide are used here.
Ion exchange. It is performed by two types of resins: anion exchange (OH–) and cation exchange (H+).
Distillation. Based on the difference in boiling temperatures of water and its impurities. Water mineralization is required after the procedure.
Depending on the results of the analysis for the volume of manganese in water, a filter with a certain filtration method is selected. Or water purification is carried out by a complex of filter components that consistently reduce liquid contaminants.
In the water of wells. As a rule, it is found in iron-containing water, the source of which is reservoirs, river, sea, and underground waters.
How does manganese get into water?
Natural manganese enters surface waters through the leaching of minerals that include manganese (manganites, pyrolusites, and others), as well as through the decomposition of plants and aquatic organisms. Manganese compounds enter water bodies from wastewater chemical industry enterprises and metallurgical plants. The manganese content in river waters ranges from 1-160 µg/cub.dm, in sea waters – up to 2 µg/cub.dm, in groundwater – from hundreds to thousands of µg/cub.dm.
In natural waters, the migration of manganese occurs in different forms: complex compounds with sulfates and bicarbonates, colloidal, ionic - in surface waters the transition occurs into high-valent oxides that precipitate, complex compounds with organic substances (organic acids, amines, humic substances and amino acids) , sorbed compounds - manganese-containing suspensions of minerals washed with water.
The balance and forms of manganese content in water are determined by temperature, oxygen content, pH, absorption, and its release by aquatic organisms and underground runoff.
Manganese is characterized by seasonal fluctuations in concentration. There are many factors that influence the level of free manganese in solution - the presence of photosynthetic organisms, the connection of lakes and rivers with reservoirs, the decomposition of biomass (dead plants and organisms), aerobic conditions.
Why is manganese dangerous?
Increased concentrations of manganese in water are indicated by black spots and stains on household appliances and plumbing. Manganese is an extremely toxic element that has a detrimental effect on the nervous and circulatory systems. Excess metal can penetrate the kidneys, endocrine glands, small intestines, bones, brain and provoke disruption of the endocrine system, pancreas, and also increase the risk of developing cancer and Parkinson's disease. Clinical manifestation chronic poisoning manganese can have pulmonary and neurological forms.
When affecting the nervous system, three stages of the disease are distinguished:
- The first stage is characterized by the predominance of functional disorders of the nervous system, expressed in increased fatigue, drowsiness, the presence of paresthesia and a gradual decrease in strength in the limbs, symptoms of autonomic dystonia, increased salivation and sweating. An objective examination may reveal muscle hypotonia, mild hypomimia (weakening of expressive movements of the facial muscles), revitalization of tendon reflexes, peripheral autonomic disorders, and distal hypoesthesia. Changes in mental activity are considered typical for this stage of intoxication: a narrowing of the range of interests, decreased activity, paucity of complaints, weakening of associative processes, decreased memory and criticism of the disease. Following changes in the psyche, as a rule, focal neurological symptoms of intoxication are observed, but due to the decreased criticism of patients towards their own condition, such changes are often not diagnosed in a timely manner. With continued contact with elevated concentrations of manganese, signs of intoxication may increase, and the process risks acquiring an irreversible organic character.
- The second stage is characterized by an increase in symptoms of toxic encephalopathy, such as mnestic-intellectual defect, severe asthenic syndrome, drowsiness, apathy, neurological signs of extrapyramidal insufficiency: bradykinesia, hypomimia, muscular dystonia with increased tone of individual muscle groups, pro- and retropulsion. Symptoms of polyneuritis, weakness, and parasthesia of the extremities worsen. There is also suppression of the function of the adrenal glands, gonads and other endocrine glands. Even stopping contact with manganese does not stop the development of this process, which continues to progress for several more years. At this stage, full recovery of health is not observed in most cases.
- For the third stage of intoxication, the so-called manganese parkinsonism, severe motor disorders are indicative: dysarthria, mask-like face, monotonous speech, writing impairment, significant hypokinesia, spastic-paretic gait, severe pro- and retropulsion, foot paresis. There is an increase in muscle tone of the extrapyramidal type, in the vast majority of cases in the legs. Sometimes there is hypotonia or muscle dystonia, a polyneuritic type of hypoesthesia. Various mental disorders are also characteristic: patients are complacent, euphoric or apathetic. Criticism towards one’s own illness is reduced or absent; violent emotions (laughter or crying) may occur. The mnestic-intellectual defect is expressed to a significant extent (difficulty in determining time, forgetfulness, deterioration in social, including professional, activities).
In view of the possibility of such severe consequences, it is important to promptly identify the presence of excess manganese in the water that a person eats and uses for water procedures, brushing teeth, etc.
Maximum permissible concentrations of manganese
According to the World Health Organization, since 1998, standards for the maximum permissible content of manganese in tap water. This figure is 0.05 mg/l. While in the USA the figures reach 0.5 mg/l. In accordance with Russian sanitary standards the level of maximum permissible manganese content in drinking water should not exceed 0.1 mg/l.
Excessive manganese content reduces the organoleptic properties of water. Content levels above 0.1 mg/l provoke the appearance of an undesirable taste in water and the appearance of stains on sanitary technical products. Accumulating in water pipes, manganese provokes the appearance of black sediment and, as a result, cloudy water.
Manganese Elimination Methods
If the presence of iron in water, as a rule, implies the presence of manganese, then manganese itself can be contained in water even if there is no excess iron in it. However, it does not change the taste, color and smell of water. In some cases, when manganese comes into contact with something, black or brown traces remain even if its concentrations in water are minimal (0.05 mg/l).
The maximum permissible concentration of manganese is determined from the point of view of its coloring properties. Depending on the ionic form, manganese is removed by ion exchange, aeration followed by filtration, catalytic oxidation, reverse osmosis or distillation. Manganese dissolved in water oxidizes more slowly than iron, so it is quite difficult to remove it from water. Shallow waters and surface wells contain colloidal and organic manganese compounds. In such waters, insoluble manganese hydroxide, the so-called “black water,” is found.
On the inner walls of heat-stressed elements and pipes, manganese is deposited as a black film, which significantly complicates the necessary heat exchange in technological processes.
In water extracted from underground wells And natural reservoirs, manganese is in divalent form. This is a partially soluble form that precipitates only when the solution is strongly heated. To purify water from manganese, it is necessary to convert manganese ions into a tri- or tetravalent form. In it, manganese forms acid salts, hydroxides, and insoluble oxides (depending on the reagent used to precipitate manganese after oxidation).
In general, water purification processes involve the oxidation of divalent manganese to tri- and tetravalent manganese. After this, tetravalent manganese reacts with oxygen or another substance, with which an insoluble precipitate is formed. And the sediment is already filtered mechanically.
Aeration followed by filtration
Aeration in the process of purifying water from manganese is carried out similarly to the reagent-free deferrization of water: a vacuum ejection apparatus is used, with which the water is saturated with oxygen, which can oxidize manganese to the required valence, and then filtered using mechanical filters (sand and others).
This method of water purification is considered the most economical. However, it is impossible to use it in all cases, because in order for the reaction of manganese oxidation with atmospheric oxygen to occur, certain conditions must be met.
This purification method is relevant when the permanganate oxidation of the source water is up to 9.5 mg/l. The presence of divalent iron in water is mandatory. During its oxidation, iron hydroxide is formed, which adsorbs divalent manganese and catalytically oxidizes it. The concentration ratio / must be at least 7/1.
Catalytic oxidation
In the process of purifying water from manganese, catalytic processes are actively used. With the help of a dosing pump, a layer of tetravalent manganese hydroxide is formed on the surface of the filter material, which is capable of oxidizing divalent manganese oxide to the trivalent form. The trivalent form of the oxide is oxidized by dissolved oxygen in the air to an insoluble form, including at high concentrations.
Reverse osmosis
To remove manganese from water, methods such as water purification by reverse osmosis and the introduction of oxidizing reagents are used. This method is used when the concentration of manganese in the source water is extremely high. Strong oxidizing agents are used as reagents: chlorine, its dioxide, sodium hypochlorite and ozone.
Demanganation with potassium permanganate
This method is used for both groundwater and surface water. The introduction of potassium permanganate into water provokes the oxidation of dissolved manganese with the formation of slightly soluble manganese oxide in accordance with the following equation:
3 Mn2+ + 2 KMnO4 + 2 H2O = 5 MnO2↓ + 4 H+ (1)
Precipitated manganese oxide (in the form of flakes) has a highly developed specific surface area, approximately 300 sq.m per 1 g of sediment. This indicates its high sorption properties. This precipitate is an excellent catalyst, since in its presence demanganation is possible at a pH of 8.5. To get rid of 1 mg of divalent manganese, you will need 1.92 m of potassium permanganate. This proportion assumes the oxidation of 97% of divalent manganese.
The next stage of water purification is the introduction of a coagulant to remove oxidation products and elements present in the water as suspension. Water after coagulation is filtered using sand filler. In addition, ultrafiltration equipment can be used.
Introduction of oxidizing reagents
The rate of oxidation of manganese by ozone, sodium hypochlorite, chlorine, and chlorine dioxide depends on the pH. When adding chlorine or sodium hypochlorite, a complete oxidation reaction is observed at a pH of 8.0-8.5, provided that the interaction between the oxidizing agent and water lasts 60-90 minutes. Often the source water needs to be alkalized. This need arises when oxygen is used as an oxidizing agent and the pH does not exceed 7.
Theoretically, to oxidize divalent manganese to tetravalent manganese, it is necessary to use 1.3 mg of reagent per 1 mg of manganese. In practice, doses are usually higher.
It is more effective to use chlorine dioxide or ozone. In this case, the oxidation of manganese will take 10-15 minutes (provided the pH value is 6.5-7.0). According to stoichiometry, the proportion of ozone should be 1.45 mg (or chlorine dioxide 1.35 mg) per 1 mg of divalent manganese. It is important to take into account that during ozonation, ozone will be decomposed by manganese oxides, so its proportion should be greater than in the theoretical calculation.
Ion exchange
To purify water in this way, hydrogen or sodium cationization is performed. During the purification process, water is treated in two layers of ion exchange material to more effectively remove all dissolved salts. Simultaneously and sequentially, a cation exchange resin with hydrogen ions H+ is used, as well as an anion exchange resin with hydroxyl ions OH-. Considering the fact that all salts soluble in water consist of anions and cations, a mixture of resins in the purified water replaces them with hydroxyl ions OH- and hydrogen H+. As a result, as a result of a chemical reaction, positive and negative ions combine and form water molecules, that is, the process of desalting water occurs.
When selecting a multicomponent complex combination ion exchange resins, effective and acceptable for water quality with a large limit of parameters, this method is the most promising in the fight against manganese and iron.
Distillation
This method involves evaporation of water followed by concentration of steam. The boiling point of water molecules is 100 degrees Celsius. Other substances have different boiling points. Thanks to this difference, water is extracted. That which boils at a lower temperature evaporates first, that which at a higher temperature evaporates after most of the water has boiled away. The result is water without impurities. However, this technology is quite energy-intensive.
