• Domestic science and medicine in the 19th - early 20th centuries Chemistry of the 19th century in medicine
• What are peptides? Types and types of peptides. All about peptides and anti-aging cosmetics with peptides Additional peptides are not formed
• Toxic effect on humans of hazardous chemicals
• Radioautography Method of autoradiography in cytology
• Identification of bacteria by antigenic structure
• Organic matter in wastewater What are organic compounds in water
• Hydrogen index (pH factor)
• What is the pH of water and why is it important to know it?
• Redox potential Redox systems
• Reversible redox system Reversible redox systems

The physical properties of ozone are very characteristic: it is an easily exploding blue gas. A liter of ozone weighs approximately 2 grams, while air weighs 1.3 grams. Therefore, ozone is heavier than air. The melting point of ozone is minus 192.7ºС. This "melted" ozone is a dark blue liquid. Ozone "ice" has a dark blue color with a violet tint and becomes opaque at a thickness of more than 1 mm. The boiling point of ozone is minus 112ºС. In the gaseous state, ozone is diamagnetic, i.e. It does not have magnetic properties, and in the liquid state it is weakly paramagnetic. The solubility of ozone in melt water is 15 times greater than that of oxygen and is approximately 1.1 g/l. A liter of acetic acid dissolves 2.5 grams of ozone at room temperature. It also dissolves well in essential oils, turpentine, carbon tetrachloride. The smell of ozone is felt at concentrations above 15 µg/m3 of air. In minimal concentrations, it is perceived as a "smell of freshness", in higher concentrations it acquires a sharp irritating tint.

Ozone is formed from oxygen according to the following formula: 3O2 + 68 kcal → 2O3. Classical examples of ozone formation: under the action of lightning during a thunderstorm; exposed to sunlight in the upper atmosphere. Ozone can also be formed during any processes accompanied by the release of atomic oxygen, for example, during the decomposition of hydrogen peroxide. The industrial synthesis of ozone is associated with the use of electrical discharges at low temperatures. Technologies for producing ozone may differ from each other. So, to obtain ozone used for medical purposes, only pure (without impurities) medical oxygen is used. The separation of the formed ozone from the oxygen impurity is usually not difficult due to differences in physical properties (ozone liquefies more easily). If certain qualitative and quantitative parameters of the reaction are not required, then obtaining ozone does not present any particular difficulties.

The O3 molecule is unstable and rather quickly turns into O2 with the release of heat. At low concentrations and without foreign impurities, ozone decomposes slowly, at high concentrations - with an explosion. Alcohol on contact with it instantly ignites. Heating and contact of ozone with even negligible amounts of the oxidation substrate (organic substances, some metals or their oxides) sharply accelerates its decomposition. Ozone can be stored for a long time at -78ºС in the presence of a stabilizer (a small amount of HNO3), as well as in vessels made of glass, some plastics or precious metals.

Ozone is the strongest oxidizing agent. The reason for this phenomenon lies in the fact that in the process of decay, atomic oxygen is formed. Such oxygen is much more aggressive than molecular oxygen, because in the oxygen molecule the deficit of electrons at the outer level due to their collective use of the molecular orbital is not so noticeable.

Back in the 18th century, it was noticed that mercury in the presence of ozone loses its luster and sticks to glass; oxidized. And when ozone is passed through an aqueous solution of potassium iodide, gaseous iodine begins to be released. The same "tricks" with pure oxygen did not work. Subsequently, the properties of ozone were discovered, which were immediately adopted by mankind: ozone turned out to be an excellent antiseptic, ozone quickly removed organic substances of any origin from water (perfumes and cosmetics, biological fluids), became widely used in industry and everyday life, and has proven itself in as an alternative to a dental drill.

In the 21st century, the use of ozone in all areas of human life and activity is growing and developing, and therefore we are witnessing its transformation from exotic into a familiar tool for everyday work. OZONE O3, an allotropic form of oxygen.

Obtaining and physical properties of ozone.

Scientists first became aware of the existence of an unknown gas when they began experimenting with electrostatic machines. It happened in the 17th century. But they began to study the new gas only at the end of the next century. In 1785, the Dutch physicist Martin van Marum created ozone by passing electrical sparks through oxygen. The name ozone appeared only in 1840; it was invented by the Swiss chemist Christian Schönbein, deriving it from the Greek ozon, smelling. The chemical composition of this gas did not differ from oxygen, but was much more aggressive. So, he instantly oxidized colorless potassium iodide with the release of brown iodine; Shenbein used this reaction to determine ozone by the degree of blueness of paper impregnated with a solution of potassium iodide and starch. Even mercury and silver, which are inactive at room temperature, oxidize in the presence of ozone.

It turned out that ozone molecules, like oxygen, consist only of oxygen atoms, only not of two, but of three. Oxygen O2 and ozone O3 are the only example of the formation of two gaseous (under normal conditions) simple substances by one chemical element. In the O3 molecule, the atoms are located at an angle, so these molecules are polar. Ozone is produced as a result of “sticking” to O2 molecules of free oxygen atoms, which are formed from oxygen molecules under the action of electrical discharges, ultraviolet rays, gamma rays, fast electrons and other high-energy particles. Ozone always smells near working electric machines, in which brushes “sparkle”, near bactericidal mercury-quartz lamps that emit ultraviolet radiation. Oxygen atoms are also released during some chemical reactions. Ozone is formed in small quantities during the electrolysis of acidified water, during the slow oxidation of wet white phosphorus in air, during the decomposition of compounds with a high oxygen content (KMnO4, K2Cr2O7, etc.), under the action of fluorine on water or on barium peroxide of concentrated sulfuric acid. Oxygen atoms are always present in a flame, so if you direct a stream of compressed air across the flame of an oxygen burner, the characteristic smell of ozone will be found in the air.

The reaction 3O2 → 2O3 is highly endothermic: 142 kJ must be spent to produce 1 mole of ozone. The reverse reaction proceeds with the release of energy and is carried out very easily. Accordingly, ozone is unstable. In the absence of impurities, gaseous ozone decomposes slowly at a temperature of 70°C and quickly above 100°C. The rate of ozone decomposition increases significantly in the presence of catalysts. They can be gases (for example, nitric oxide, chlorine), and many solid substances (even vessel walls). Therefore, pure ozone is difficult to obtain, and working with it is dangerous due to the possibility of an explosion.

It is not surprising that for many decades after the discovery of ozone, even its basic physical constants were unknown: for a long time no one managed to obtain pure ozone. As D.I. Mendeleev wrote in his textbook Fundamentals of Chemistry, “with all methods of preparing gaseous ozone, its content in oxygen is always insignificant, usually only a few tenths of a percent, rarely 2%, and only at very low temperatures does it reach 20%.” Only in 1880, the French scientists J. Gotfeil and P. Chappui obtained ozone from pure oxygen at a temperature of minus 23 ° C. It turned out that in a thick layer ozone has a beautiful blue color. When the cooled ozonated oxygen was slowly compressed, the gas turned dark blue, and after the rapid release of pressure, the temperature dropped even more and dark purple liquid ozone droplets formed. If the gas was not cooled or compressed quickly, then the ozone instantly, with a yellow flash, turned into oxygen.

Later, a convenient method for the synthesis of ozone was developed. If a concentrated solution of perchloric, phosphoric or sulfuric acid is subjected to electrolysis with a cooled anode made of platinum or lead(IV) oxide, then the gas released at the anode will contain up to 50% ozone. The physical constants of ozone were also refined. It liquefies much lighter than oxygen - at a temperature of -112 ° C (oxygen - at -183 ° C). At -192.7 ° C, ozone solidifies. Solid ozone is blue-black in color.

Experiments with ozone are dangerous. Gaseous ozone is capable of exploding if its concentration in the air exceeds 9%. Liquid and solid ozone explode even more easily, especially when in contact with oxidizing substances. Ozone can be stored at low temperatures in the form of solutions in fluorinated hydrocarbons (freons). These solutions are blue in color.

Chemical properties of ozone.

Ozone is characterized by an extremely high reactivity. Ozone is one of the strongest oxidizing agents and is inferior in this respect only to fluorine and oxygen fluoride OF2. The active principle of ozone as an oxidizing agent is atomic oxygen, which is formed during the decay of the ozone molecule. Therefore, acting as an oxidizing agent, the ozone molecule, as a rule, “uses” only one oxygen atom, while the other two are released in the form of free oxygen, for example, 2KI + O3 + H2O → I2 + 2KOH + O2. Many other compounds are oxidized in the same way. However, there are exceptions when the ozone molecule uses all three oxygen atoms it has for oxidation, for example, 3SO2 + O3 → 3SO3; Na2S + O3 → Na2SO3.

A very important difference between ozone and oxygen is that ozone exhibits oxidizing properties even at room temperature. For example, PbS and Pb(OH)2 do not react with oxygen under normal conditions, while in the presence of ozone the sulfide is converted to PbSO4, and the hydroxide to PbO2. If a concentrated solution of ammonia is poured into a vessel with ozone, white smoke will appear - this ozone has oxidized ammonia to form ammonium nitrite NH4NO2. Especially characteristic of ozone is the ability to “blacken” silver items with the formation of AgO and Ag2O3.

By attaching one electron and turning into a negative ion O3-, the ozone molecule becomes more stable. "Ozonate salts" or ozonides containing such anions have been known for a long time - they are formed by all alkali metals except lithium, and the stability of ozonides increases from sodium to cesium. Some ozonides of alkaline earth metals are also known, for example Ca(O3)2. If a stream of gaseous ozone is directed to the surface of a solid dry alkali, an orange-red crust is formed containing ozonides, for example, 4KOH + 4O3 → 4KO3 + O2 + 2H2O. At the same time, solid alkali effectively binds water, which prevents ozonide from immediate hydrolysis. However, with an excess of water, ozonides rapidly decompose: 4KO3 + 2H2O → 4KOH + 5O2. Decomposition also occurs during storage: 2KO3 → 2KO2 + O2. Ozonides are highly soluble in liquid ammonia, which made it possible to isolate them in their pure form and study their properties.

Organic substances that ozone comes into contact with, it usually destroys. So, ozone, unlike chlorine, is able to split the benzene ring. When working with ozone, you can not use rubber tubes and hoses - they will instantly “leak out”. Ozone reacts with organic compounds with the release of a large amount of energy. For example, ether, alcohol, cotton wool moistened with turpentine, methane and many other substances ignite spontaneously when in contact with ozonized air, and mixing ozone with ethylene leads to a strong explosion.

The use of ozone.

Ozone does not always "burn" organic matter; in a number of cases it is possible to carry out specific reactions with highly dilute ozone. For example, ozonation of oleic acid (it is found in large quantities in vegetable oils) produces azelaic acid HOOC(CH2)7COOH, which is used to produce high-quality lubricating oils, synthetic fibers, and plasticizers for plastics. Similarly, adipic acid is obtained, which is used in the synthesis of nylon. In 1855, Schönbein discovered the reaction of unsaturated compounds containing C=C double bonds with ozone, but it was not until 1925 that the German chemist H. Staudinger established the mechanism of this reaction. The ozone molecule joins the double bond with the formation of ozonide - this time organic, and an oxygen atom takes the place of one of the C \u003d C bonds, and the -O-O- group takes the place of the other. Although some organic ozonides have been isolated in pure form (for example, ethylene ozonide), this reaction is usually carried out in dilute solution, since ozonides in the free state are very unstable explosives. The ozonation reaction of unsaturated compounds enjoys great respect among organic chemists; problems with this reaction are often offered even at school olympiads. The fact is that when ozonide is decomposed by water, two molecules of aldehyde or ketone are formed, which are easy to identify and further establish the structure of the original unsaturated compound. Thus, at the beginning of the 20th century, chemists established the structure of many important organic compounds, including natural ones, containing C=C bonds.

An important field of application of ozone is the disinfection of drinking water. Usually the water is chlorinated. However, some impurities in the water under the action of chlorine are converted into compounds with a very unpleasant odor. Therefore, it has long been proposed to replace chlorine with ozone. Ozonated water does not acquire foreign smell or taste; when many organic compounds are completely oxidized with ozone, only carbon dioxide and water are formed. Purify with ozone and waste water. The products of ozone oxidation even of such pollutants as phenols, cyanides, surfactants, sulfites, chloramines are harmless compounds without color and odor. Excess ozone quickly decomposes with the formation of oxygen. However, water ozonation is more expensive than chlorination; in addition, ozone cannot be transported and must be produced on site.

Ozone in the atmosphere.

There is not much ozone in the Earth's atmosphere - 4 billion tons, i.e. on average only 1 mg/m3. The concentration of ozone increases with distance from the Earth's surface and reaches a maximum in the stratosphere, at an altitude of 20-25 km - this is the "ozone layer". If all the ozone from the atmosphere is collected near the Earth's surface at normal pressure, a layer only about 2-3 mm thick will be obtained. And such small amounts of ozone in the air actually provide life on Earth. Ozone creates a "protective screen" that does not allow the harsh ultraviolet rays of the sun to reach the Earth's surface, which are detrimental to all living things.

In recent decades, much attention has been paid to the emergence of so-called "ozone holes" - areas with a significantly reduced content of stratospheric ozone. Through such a "leaky" shield, the harder ultraviolet radiation of the Sun reaches the Earth's surface. Therefore, scientists have been monitoring the ozone in the atmosphere for a long time. In 1930, the English geophysicist S. Chapman proposed a scheme of four reactions to explain the constant concentration of ozone in the stratosphere (these reactions are called the Chapman cycle, in which M means any atom or molecule that carries away excess energy):

O + O + M → O2 + M

O + O3 → 2O2

O3 → O2 + O.

The first and fourth reactions of this cycle are photochemical, they are under the influence of solar radiation. For the decomposition of an oxygen molecule into atoms, radiation with a wavelength of less than 242 nm is required, while ozone decays when light is absorbed in the region of 240-320 nm (the latter reaction just protects us from hard ultraviolet, since oxygen does not absorb in this spectral region) . The remaining two reactions are thermal, i.e. go without the action of light. It is very important that the third reaction leading to the disappearance of ozone has an activation energy; this means that the rate of such a reaction can be increased by the action of catalysts. As it turned out, the main catalyst for ozone decay is nitric oxide NO. It is formed in the upper atmosphere from nitrogen and oxygen under the influence of the most severe solar radiation. Once in the ozonosphere, it enters into a cycle of two reactions O3 + NO → NO2 + O2, NO2 + O → NO + O2, as a result of which its content in the atmosphere does not change, and the stationary ozone concentration decreases. There are other cycles leading to a decrease in the ozone content in the stratosphere, for example, with the participation of chlorine:

Cl + O3 → ClO + O2

ClO + O → Cl + O2.

Ozone is also destroyed by dust and gases, which in large quantities enter the atmosphere during volcanic eruptions. Recently, it has been suggested that ozone is also effective in destroying hydrogen released from the earth's crust. The totality of all reactions of formation and decay of ozone leads to the fact that the average lifetime of an ozone molecule in the stratosphere is about three hours.

It is assumed that in addition to natural, there are also artificial factors affecting the ozone layer. A well-known example is freons, which are sources of chlorine atoms. Freons are hydrocarbons in which hydrogen atoms are replaced by fluorine and chlorine atoms. They are used in refrigeration and for filling aerosol cans. Ultimately, freons get into the air and slowly rise higher and higher with air currents, finally reaching the ozone layer. Decomposing under the action of solar radiation, freons themselves begin to catalytically decompose ozone. It is not yet known exactly to what extent freons are to blame for the "ozone holes", and, nevertheless, measures have long been taken to limit their use.

Calculations show that in 60-70 years the ozone concentration in the stratosphere can decrease by 25%. And at the same time, the concentration of ozone in the surface layer - the troposphere, will increase, which is also bad, since ozone and the products of its transformations in the air are poisonous. The main source of ozone in the troposphere is the transfer of stratospheric ozone with air masses to the lower layers. Approximately 1.6 billion tons enter the ground layer of ozone annually. The lifetime of an ozone molecule in the lower part of the atmosphere is much longer - more than 100 days, since in the surface layer there is less intensity of ultraviolet solar radiation that destroys ozone. Usually, there is very little ozone in the troposphere: in clean fresh air, its concentration averages only 0.016 μg / l. The concentration of ozone in the air depends not only on altitude, but also on the terrain. Thus, there is always more ozone over the oceans than over land, since ozone decays more slowly there. Measurements in Sochi showed that the air near the sea coast contains 20% more ozone than in the forest 2 km from the coast.

Modern humans breathe much more ozone than their ancestors. The main reason for this is the increase in the amount of methane and nitrogen oxides in the air. Thus, the content of methane in the atmosphere has been constantly growing since the middle of the 19th century, when the use of natural gas began. In an atmosphere polluted with nitrogen oxides, methane enters a complex chain of transformations involving oxygen and water vapor, the result of which can be expressed by the equation CH4 + 4O2 → HCHO + H2O + 2O3. Other hydrocarbons can also act as methane, for example, those contained in the exhaust gases of cars during the incomplete combustion of gasoline. As a result, in the air of large cities over the past decades, the concentration of ozone has increased tenfold.

It has always been believed that during a thunderstorm, the concentration of ozone in the air increases dramatically, since lightning contributes to the conversion of oxygen into ozone. In fact, the increase is insignificant, and it does not occur during a thunderstorm, but several hours before it. During a thunderstorm and for several hours after it, the concentration of ozone decreases. This is explained by the fact that before a thunderstorm there is a strong vertical mixing of air masses, so that an additional amount of ozone comes from the upper layers. In addition, before a thunderstorm, the electric field strength increases, and conditions are created for the formation of a corona discharge at the points of various objects, for example, the tips of branches. It also contributes to the formation of ozone. And then, with the development of a thundercloud, powerful ascending air currents arise under it, which reduce the ozone content directly under the cloud.

An interesting question is about the ozone content in the air of coniferous forests. For example, in the Course of Inorganic Chemistry by G. Remy, one can read that “ozonized air of coniferous forests” is a fiction. Is it so? No plant emits ozone, of course. But plants, especially conifers, emit a lot of volatile organic compounds into the air, including unsaturated hydrocarbons of the terpene class (there are a lot of them in turpentine). So, on a hot day, a pine tree releases 16 micrograms of terpenes per hour for every gram of dry weight of needles. Terpenes are distinguished not only by conifers, but also by some deciduous trees, among which are poplar and eucalyptus. And some tropical trees are able to release 45 micrograms of terpenes per 1 g of dry leaf mass per hour. As a result, one hectare of coniferous forest can release up to 4 kg of organic matter per day, and about 2 kg of deciduous forest. The forested area of ​​the Earth is millions of hectares, and all of them release hundreds of thousands of tons of various hydrocarbons, including terpenes, per year. And hydrocarbons, as was shown in the example of methane, under the influence of solar radiation and in the presence of other impurities contribute to the formation of ozone. Experiments have shown that, under suitable conditions, terpenes are indeed very actively involved in the cycle of atmospheric photochemical reactions with the formation of ozone. So ozone in a coniferous forest is not an invention at all, but an experimental fact.

Ozone and health.

What a pleasure to take a walk after a thunderstorm! The air is clean and fresh, its invigorating jets seem to flow into the lungs without any effort. “It smells like ozone,” they often say in such cases. “Very good for health.” Is it so?

Once upon a time, ozone was certainly considered beneficial to health. But if its concentration exceeds a certain threshold, it can cause a lot of unpleasant consequences. Depending on the concentration and time of inhalation, ozone causes changes in the lungs, irritation of the mucous membranes of the eyes and nose, headache, dizziness, lowering blood pressure; ozone reduces the body's resistance to bacterial infections of the respiratory tract. Its maximum permissible concentration in the air is only 0.1 µg/l, which means that ozone is much more dangerous than chlorine! If you spend several hours indoors with an ozone concentration of only 0.4 μg / l, chest pains, coughing, insomnia may appear, visual acuity decreases. If you breathe in ozone for a long time at a concentration of more than 2 μg / l, the consequences can be more severe - up to stupor and a decline in cardiac activity. With an ozone content of 8-9 µg/l, pulmonary edema occurs after a few hours, which is fraught with death. But such negligible amounts of a substance are usually difficult to analyze by conventional chemical methods. Fortunately, a person feels the presence of ozone already at very low concentrations - about 1 μg / l, at which starch iodine paper is not going to turn blue. To some people, the smell of ozone in small concentrations resembles the smell of chlorine, to others - to sulfur dioxide, to others - to garlic.

It's not just ozone itself that's poisonous. With its participation in the air, for example, peroxyacetyl nitrate (PAN) CH3-CO-OONO2 is formed - a substance that has a strong irritant, including tear, effect that makes breathing difficult, and in higher concentrations causes heart paralysis. PAN is one of the components of the so-called photochemical smog formed in summer in polluted air (this word is derived from the English smoke - smoke and fog - fog). The concentration of ozone in smog can reach 2 μg/l, which is 20 times higher than the maximum allowable. It should also be taken into account that the combined effect of ozone and nitrogen oxides in the air is ten times stronger than each substance separately. Not surprisingly, the consequences of such smog in large cities can be catastrophic, especially if the air above the city is not blown by "drafts" and a stagnant zone forms. So, in London in 1952, more than 4,000 people died from smog within a few days. A smog in New York in 1963 killed 350 people. Similar stories were in Tokyo and other major cities. Not only people suffer from atmospheric ozone. American researchers have shown, for example, that in areas with a high content of ozone in the air, the service life of car tires and other rubber products is significantly reduced.

How to reduce the ozone content in the ground layer? Reducing methane emissions into the atmosphere is hardly realistic. There remains another way - to reduce emissions of nitrogen oxides, without which the cycle of reactions leading to ozone cannot go. This path is also not easy, since nitrogen oxides are emitted not only by cars, but also (mainly) by thermal power plants.

Ozone sources are not only on the street. It is formed in x-ray rooms, in physiotherapy rooms (its source is mercury-quartz lamps), during the operation of copiers (copiers), laser printers (here the reason for its formation is a high-voltage discharge). Ozone is an inevitable companion for the production of perhydrol, argon arc welding. To reduce the harmful effects of ozone, it is necessary to equip the hood with ultraviolet lamps, good ventilation of the room.

And yet, it is hardly correct to consider ozone, of course, harmful to health. It all depends on its concentration. Studies have shown that fresh air glows very weakly in the dark; the cause of the glow is an oxidation reaction involving ozone. Glow was also observed when water was shaken in a flask, into which ozonized oxygen was preliminarily filled. This glow is always associated with the presence of small amounts of organic impurities in the air or water. When mixing fresh air with an exhaled person, the intensity of the glow increased tenfold! And this is not surprising: microimpurities of ethylene, benzene, acetaldehyde, formaldehyde, acetone, and formic acid were found in the exhaled air. They are "highlighted" by ozone. At the same time, "stale", i.e. Completely devoid of ozone, although very clean, the air does not cause a glow, and a person feels it as "stale". Such air can be compared to distilled water: it is very pure, contains practically no impurities, and it is harmful to drink it. So the complete absence of ozone in the air, apparently, is also unfavorable for humans, since it increases the content of microorganisms in it, leads to the accumulation of harmful substances and unpleasant odors, which ozone destroys. Thus, it becomes clear the need for regular and long-term ventilation of the premises, even if there are no people in it: after all, the ozone that has entered the room does not linger in it for a long time - it partially decomposes, and largely settles (adsorbs) on the walls and other surfaces. It is difficult to say how much ozone should be in the room. However, in minimal concentrations, ozone is probably necessary and useful.

Thus, ozone is a time bomb. If it is used correctly, it will serve humanity, but as soon as it is used for other purposes, it will instantly lead to a global catastrophe and the Earth will turn into a planet like Mars.

The interaction of pollutants with ozone occurs due to a direct reaction with ozone molecules or with radicals that appear during its decay. Ozone interacts more actively with anions than with neutral and cationic substances.

Ozone, being an active oxidizing agent, interacts with many organic and inorganic substances. Of the halogens, fluorine does not react with ozone and chlorine practically does not interact. Bromine is oxidized by ozone first to hypobromite and then to bromate compounds. In this case, the resulting bromide can interact in parallel with substances of organic origin and ammonia. Iodine is oxidized by ozone very quickly with the formation of iodates and iodous acid. Salts of halogenated acids are no longer susceptible to ozone oxidation. Almost neutral to ozone are nitrogen and its compounds, including ammonia and ammonium ions, as well as nitrates, with the exception of amines, which interact well with hydroxyl radicals. Toxic cyanides are easily oxidized by ozone to cyanates, further oxidation of which occurs very slowly and accelerates only in the presence of copper ions, slowing down in the presence of iron ions in solution. Sulfur and sulfite, when interacting with ozone, are oxidized to sulfates. As for reactions with metals, ozone rather actively oxidizes iron and manganese, cobalt and nickel, forming oxides and hydroxides that are removed from the solution during flocculation or filtration. Chromium is practically passive with respect to ozone, although under certain conditions it can be oxidized by it to the maximum oxidation state, hexavalent chromium.

1.1 Introduction

Ozone was discovered in 1840 by the Swiss chemist Christian Schombein, after experiments on the electrolysis of acids. Very soon, as a result of a number of studies, it was shown that ozone is triatomic oxygen, a gas under standard conditions, the characteristic properties of which are its ability to oxidize many substances and disinfect microflora. These properties were very soon used in the drinking water treatment industry. At the very end of the 90s of the 19th century, attempts were made in the Netherlands and Germany to disinfect drinking water using ozone. The generally recognized date of birth of ozone water treatment technology is considered to be 1906, when a water treatment plant began operating in the French city of Nice, bearing the symbolic name "Good Way" ("bon voyage") with a water capacity of 22.5 m³ / day. The station operated successfully until 1970, when it was modernized. This practice has since become widespread, as evidenced by the following data: From 30 to 300, and in the USA from 1954 to 1997 from 10 to 5500, respectively.

In Russia, the effectiveness of ozonation for water treatment was evaluated almost at the same time as abroad. In 1901, the 5th water congress heard a report by engineer N.P. Zimin on water ozonation; the latter characterized "ozonation of water as a means of eliminating the shortcomings of its filtration in urban water supply systems."

In 1905, an experimental plant for water ozonation was put into operation at the Peter and Paul Hospital in St. Petersburg. It was found that the number of bacteria was reduced by an average of 98.8%, the taste improved and there was no color in the purified water. In 1911, the largest water ozonation station in the world at that time began operating in St. Petersburg. When opened, its capacity was 44.5 thousand m³/day of treated water.

An overview of ideas about ozone, its production and application in various fields at the beginning of the 20th century is given in the book of the Russian engineer V.V. Karaff-Korbutt "Ozone and its application in industry and sanitation", published in 1912.

One of the first Soviet monographs on this topic is the book by V.F. Kozhinova and I.V. Kozhinov "Ozonation of water". These works belong to the last century. Significant progress has been made in the production of ozone recently, and very promising new uses for ozone have been opened up.

1.2 Ozone, its properties and basic reactions with various substances.

1.2.1 Physical and chemical properties of ozone.

Under normal conditions, ozone is a gaseous, colorless substance with a pungent odor. It is believed that the smell of ozone is the smell of fresh air after a thunderstorm. This is true, but only if its concentration is very low and is a fraction of the maximum permissible concentrations (MPC). A detailed description of the physicochemical properties of ozone is considered in numerous works, in particular. Some basic physical and chemical properties of ozone are given in the table 1.1 .

Table 1.1.Basic physical and chemical properties of ozone.

Pure ozone is explosive. It is not stable and decomposes quickly. The decomposition of ozone is influenced by many factors: temperature, pH, the presence of substances to be oxidized, etc.

1.2.2 Solubility of ozone in water

When ozone dissolves in water, its concentration gradually increases and reaches the limit values ​​for these conditions.

The solubility of ozone in water can be expressed either in the form of the so-called Bunzea coefficient - β, which shows the ratio of the volume of dissolved ozone reduced to normal conditions to the volume of water (Voz/Vv), or in absolute values ​​of dissolved ozone (g/l). It is assumed that the dissolution process obeys Henry's law, according to which the amount of dissolved ozone is proportional to the pressure of gaseous ozone over the solution. This law can be written as:

C static = β

C stats- ozone solubility, g/l;

β is the Bunsen coefficient;

M– ozone density = 2.14 g/l;

Pγ is the partial pressure of ozone in the considered gaseous medium.

It should be noted that the solubility of ozone is much higher than the main atmospheric gases - nitrogen and oxygen, but weaker than such oxidizing agents as chlorine and chlorine dioxide. The solubility of ozone increases with decreasing water temperature. At the same time, there is a large scatter in the experimental data of various authors, presented in the table 1.2 .

Table 1.2 Solubility of ozone in water.

T, °С		According to		According to		According to
	Β (l O3/l H2O)	Solubility, g/l	Β (l O3/l H2O)	Solubility, g/l	Β (l O3/l H2O)	Solubility, g/l

1.2.3 Decomposition of ozone in water

Simultaneously with the dissolution of ozone in water, its decomposition occurs. At the same time, the rate of its decay, as well as the reciprocal value “lifetime”, depends on the temperature of the water and, mainly, on the composition of the water. First of all, from the presence of various impurities in the water, especially some organic compounds and metal ions.

The lifetime in single-distilled water is 20 minutes, and in ordinary water a few minutes.

1.3 Reactions of ozone with inorganic substances.

Ozone can react with various substances in water by two different mechanisms - directly as ozone (in molecular form) and in the form of the OH* radical, which occurs when ozone decomposes in water. It is believed that in neutral water these 2 reaction channels are distributed equally. In an acidic medium, the molecular mechanism predominates, while in an alkaline medium, a radical one.

Since ozone acts as an oxidizing agent in chemical reactions, one can judge its oxidizing ability by the so-called oxidation potential value. The value of the values ​​of the oxidation potentials of various substances - oxidizing agents are given in the table 1.3 .

Table 1.3. Redox potentials of various substances.

From table 1.3. It follows that ozone is a very strong oxidizing agent. Of the stable substances second only to fluorine and outperforms chlorine by one and a half times.

1.3.1 Reaction of ozone with metals.

Being a strong oxidizing agent, ozone in the gas phase oxidizes most metals with the exception of gold and some metals of the platinum group, oxides of higher oxidation states, but these reactions usually require the presence of traces of moisture. Alkali and alkaline earth metals are oxidized by ozone in the same way as by oxygen, only at a faster rate. Interestingly, plates of gold and platinum (and, to a lesser extent, silver and copper) acquire a negative electrical charge in an atmosphere of dry ozone.

Metallic silver is well oxidized by ozone, both in wet and dry gas in the temperature range from room temperature to 1000C with the formation of brown oxide Ag2O. The latter is a good catalyst for ozone decomposition.

Metallic mercury, like silver, is oxidized by ozone already at room temperature, while the surface loses its inherent mobility, sticks to glass, and the mercury meniscus becomes flatter. Molten tin at 5000C in the presence of 1% ozone is covered with an oxide film. Ozone in the presence of water oxidizes lead to form hydroxide. In the absence of moisture, the main product of this reaction is dark brown lead dioxide. Polishing surfaces of copper, zinc, iron, various steels in an atmosphere of moist ozone are covered with loose oxide films, as in ordinary atmospheric corrosion. In a dry atmosphere, these surfaces are passivated by ozone, forming protective films. A similar picture is observed for copper and zinc.

The interaction of metals with ozone in solutions is more diverse. So, if ozone in the gas phase does not affect gold, then its small additions contribute to the dissolution of gold in solutions of potassium cyanide by 1.5-2 times and silver by 3 times.

The strong oxidizing properties of ozone are proposed to be used for the selective oxidation of minerals in an aqueous medium. This is how barium and strontium sulfates were obtained. Heavy metal sulfides are valuable metallurgical raw materials, so their conversion into water-soluble sulfates (or oxides) has attracted attention for a very long time. At present, a large laboratory or semi-industrial array of experimental data has been accumulated on this issue. We are talking about the creation based on the leaching of metals by ozone from acid slurry sulfides. This hydrometallurgical technology has a number of advantages over currently used pyrometallurgy.

1.3.2 Reactions of ozone with non-metals.

Non-metals react with ozone in different ways. Dry phosphorus, both white and red, is oxidized by ozone to P2O5. Arsenic, like phosphorus, sulfur, selenium, tellurium, in a dry atmosphere is oxidized to oxides, and in the presence of water, the corresponding acids are formed, and in alkaline water, salts.

Nitrogen does not react with ozone, but nitrogen oxides (some of them) react very easily, making it possible to eliminate them from the gas emissions of a number of enterprises. The second nasty ingredient in many gaseous emissions, sulfur dioxide, does not react with ozone in the gas phase, but reacts in solution. Cyanides (cyanide ions) readily react with ozone in aqueous solution, and these processes, as well as the elimination of iron and manganese from water, are discussed in detail below.

Ozone oxidizes all halogens, except for fluorine, and with an increase in the element's atomic number, the ease of oxidation increases. These processes are briefly discussed in the section on water treatment in swimming pools.

1.4. Reactions of ozone with organic compounds.

It is rather difficult to characterize the reactions of all basic organic substances with ozone. It is possible only to note some general points when considering the direct effects of ozone.

Saturated alkyl compounds react very slowly with ozone. Most chlorinated hydrocarbons and even unsaturated hydrocarbons do not react directly with ozone. In this case, indirect interaction with ozone through the OH* radical is necessary. Benzene is oxidized by ozone very slowly, and polycyclic hydrocarbons are faster. The reaction time of ozone with phenolic compounds is a few seconds.

Carboxylic acids, keto acids and a number of similar compounds are the final stable products of the process of oxidation of organic substances with ozone.

Amines at neutral pH values ​​react very slowly with ozone, at pH > 8, oxidation reactions are faster. However, in general, the oxidation reactions of amines proceed through OH radicals. Quaternary amines (aromatic amines) react with ozone faster.

Alcohols can interact with ozone, forming hydroperoxides as intermediates. At the same time, they are oxidized to carboxylic acids, while secondary alcohols are oxidized to ketones. Carboxylic acids with ozone react weakly or do not react at all.

Mercaptans are oxidized with ozone to sulfonic acids. Bisulfites and sulfonic compounds are intermediates. Amino acids containing sulfur (cysteine, cestine and methionine) react quickly.

Amino acids (a component of proteins) react by an electrophilic mechanism.

Among pesticides containing esters of phosphoric acid, parathion is the most well-known. Ozonation of this compound results in paraoxon, which is more toxic than parathion. Further ozonation converts paraoxon into less toxic substances (for example, into nitrophenol, which is then oxidized to end products - nitrates and CO2).

1.5. Ozone as an inactivator of microflora.

As mentioned above, ozone has a powerful bactericidal and virulent (inactivating viruses) effect.

The scientific literature (especially the popular one) often claims that ozone does inactivate bacteria and viruses more than chlorine (and this will be illustrated below), but this benefit must be quantified with certain reservations.

Currently, when evaluating the effectiveness of a disinfectant, the so-called SHT criterion, i.e. the product of the concentration of the reagent and the duration of the action.

It can be said that:

EXPOSURE (INACTIVATION) = Concentration * Exposure time.

Table 2.1. presented for comparison values SHT criteria for various microorganisms - disinfecting agents.

Table 2.1. Meaning SHT criterion for various microorganisms (99% inactivation at 5-25 °C. SHT criterion (Mg/l*min)

Clearly, ozone is superior to disinfectants such as chlorine, chloramine, and chlorine dioxide, but in different ways for different pathogens. For pathogens such as Escherichia coli (E-coli), ozone is more effective than chlorine, but not by much. At the same time, for cryptosporidium, the ratio SHT criteria for these disinfectants approaches 1000. In principle, ozone can compete with disinfectants such as chlorine, bromine, iodine, chlorine dioxide and silver.

Molecular gaseous chlorine, dissolving in water, decomposes, producing hydrochloric acid HOCl, which, in turn, dissociates in water into the anion СlО- and the cation Н+. The degree of this dissociation is determined by the acidity of the medium. It has been established that at pH = 8 the concentration of non-dissociated acid is ≈ 20%, and at pH = 7, the concentration of HClO is ≈80%. Since it is HClO that has a strong bactericidal effect, when using chlorine (even in the form of hypochlorite), it is necessary to maintain the optimal pH value.

Iodine, as a disinfectant, is used to inactivate microflora in small water treatment systems and sometimes in small swimming pools. In terms of its disinfecting properties, iodine is weaker than chlorine, and especially ozone, but it is more convenient to transport.

Bromine, in principle, can be used for disinfection purposes, however, in the presence of other oxidizing agents, it forms bromates, derivatives of the acid HBrO3, which are very harmful and have a low MAC value. This problem - the formation of bromates during the ozonation of bromine-containing waters - is quite serious, and we will dwell on it in the section "Use of ozone for the preparation of drinking water". Silver is an exotic but very weak disinfectant and is rarely used.

In addition, recently, domestic and foreign industry offers a number of organic substances with a strong disinfectant effect. However, they all have certain disadvantages and have not yet been widely used.

Thus, only chlorine can be a real competitor to ozone. Unfortunately, chlorine has significant disadvantages:

For a long time, liquid chlorine from pressurized cylinders was used, which was a big problem in terms of safety. Currently, chlorine is obtained or hypochlorite is used, which, dissolving in water, creates the required concentration of free chlorine. It should be noted that the term "free chlorine" refers to the concentration of hypochlorous acid HClO. The use of hypochlorite necessitates the storage of a supply of reagent, but hypochlorite decomposes during storage, and the free chlorine content drops.

One of the main unpleasant properties of chlorine is that when it reacts with most organic compounds, a whole range of organochlorine derivatives arises, most of which are highly toxic. Chlorophenols and especially polychlorophenols, some of the latter, the so-called dioxins, are among the strongest organic poisons known at present, and the effect of these toxins is to destroy the human immune system, so that when talking about dioxins, the term "chemical AIDS" is sometimes used.

Chlorine reacts very easily with ammonia to form chloramines. These substances have a very weak disinfectant effect, but are extremely irritating to the mucous membranes of the eyes and nasopharynx. Chloramines are often referred to as "combined chlorine". This combined chlorine is 5-10 times more irritant than free chlorine.

Ozone can also form intermediate compounds (by products) during ozonation of gaseous and condensed media. Theoretically, it can be assumed that those formed by products are more toxic than ozone.

This problem has been the subject of research by many scientists around the world. The concentrations and composition of the intermediates that occur during ozonation are highly dependent on whether drinking water or waste water is being ozonated. Of course, in the first case, much less by products are formed and their composition is more obvious. All these issues will be discussed in the relevant sections of the review. The fairly consistent results of years of research can be summarized as follows:

In the vast majority of cases, the intermediate products of ozone oxidation of pollutants are LESS TOXIC than the original ingredients.

A direct comparison of the intermediates formed during comparative experiments on chlorination and ozonation showed that in the first case, much more undesirable by products are formed.

Direct comparison of chlorine and ozone as microflora disinfectants has been made in numerous experimental studies and at operating water treatment plants. Here are just a few of the well-known works:

M. Kane and Gleckner studied the effect of ozone and chlorine on cysts (dense shells that form around single-celled organisms) of Endamoeba hystolica and on the bacteria accompanying these cultures. It has been established that the time required for the destruction of these organisms at a residual ozone concentration of 0.3 mg/l is 2-7.5 minutes, and for chlorine (residual concentration of 0.5-1 mg/l) it is much longer - 15-20 minutes.

In the 1940s and 1960s, virologists in the United States and Germany conducted a series of studies with suspensions of the poliovirus in order to inactivate it with chlorine, ozone, and chlorine dioxide.

The conclusions from these studies can be summarized as follows:

Inactivation of the poliomyelitis virus with chlorine is achieved with a dose of 0.1 mg/l at a water temperature of 18 ºС; at a water temperature of 7 ºС, the dose of chlorine should be at least 0.25 mg/l.

Virus inactivation with ozone is achieved with a dose of 0.1 mg/l at a water temperature of 18 ºС, for cold water 7ºС the dose should be increased to 0.15 mg/l.

When using chlorine dioxide, a dose of 0.6 mg/l (18 ºC) must be used. For water with a temperature of 7 ºС, the dose of chlorine dioxide should be 1 mg/l.

According to Naumann, poliomyelitis pathogens are destroyed by ozone in 2 minutes at a concentration of 0.45 mg/l, while with chlorination at a dose of 1 mg/l, this takes 3 hours.

According to some authors, ozone successfully eliminates microalgae and protozoa more actively than chlorine. So ozone at a concentration of 15 mg/l in 3 minutes destroys the species of protozoa, which retain their activity when water is treated with a dose of chlorine of 250 mg/l for a long time.

Larvae of the mussel zebra mussel died by 90% at an ozone dose of 0.9-1.0 mg/l, 98% at a dose of 2 mg/l, and completely at a dose of 3 mg/l. Adult forms of the mollusk died after a longer treatment with ozonized water (up to 30 min).

True, algae blooms, which usually thrive in open pools in sunlight, are slightly affected by ozone. Here shock doses of chlorine are used. This treatment is usually carried out at night during the preventive cleaning of such pools.

Ridenor and Ingalls from the USA treated suspensions of e-coli in distilled water with chlorine and ozone at Hp = 6.8 and a temperature of 1°C. Under these conditions, the bactericidal doses that caused the death of 99% of e-coli colonies were 0.25–0.3 mg/l for 16 min for chlorine, and 0.5 mg/l for 1 min for ozone.

The long history of the use of these two disinfectants in large wastewater treatment plants contains a wealth of factual material that makes it possible to judge their advantages and disadvantages. In the already mentioned book "Ozonation of Water" a number of interesting examples are given.

Thus, during the long-term operation of the station in Nice, the appearance of bacteria Escherichia coli and Clostridium pertringers has never been detected in ozonated water.

At the Belmont Filtration Station in Philadelphia (USA), ozonation of water has shown results in eliminating e-coli more successfully than results achieved with chlorination.

Studies on water ozonation were carried out at the Eastern Waterworks in Moscow. The effect of water disinfection with ozone when the total number of bacteria in 1 ml is 800-1200 units. is: at an ozone dose of 1 ml/l 60-65%, at a dose of 2 ml/l - 85%, at a dose of 3 ml/l - 90-95%. An acceptable dose of ozone should be considered 3-4 ml/l.

At the Rublevskaya waterworks (Moscow), ozonation of the water of the Moskva River was carried out. The total number of bacteria in 1 ml of water after the introduction of ozone decreased by 92-99% within a time period of 1-25 minutes. The germicidal dose of ozone corresponded to that after treatment, which could not detect e-coli in 500 ml. water. An increase in turbidity from 6.8 to 12 mg/l and color from 3.2 to 18 degrees. required an increase in the bactericidal dose of ozone from 3.2 to 4.1 mg/L.

Thus, comparing the work of the French water treatment station in Saint-Maur and the station in Chicago (USA), V.F. Kozhinov notes that in the first case, diseases of “water origin” were registered only in 1 case per 100 thousand inhabitants, although the concentration of residual ozone in water did not exceed 0.05 mg/l.

At the same time, there were outbreaks of gastrointestinal diseases in Chicago despite the very high chlorine content in tap water.

One of the greatest hygienists of the last century, Watson, expressed the following opinion at the international congress on water supply in Stockholm (July 1964): chlorine. Experiments carried out in Ashton (England) have shown that water decontaminated by ozone, circulating in a serviceable water supply network of pipelines, does not deteriorate in its quality. Control samples of ozonized water taken from the network were completely equivalent to samples containing residual chlorine in water taken from other sources. It has also been established that small amounts of residual chlorine present in pipelines cannot have any disinfecting effect on pollution caused by damage to communications. Those. the presence of residual chlorine in pipelines does not yet mean the indispensable bacterial purity of water, although it is often considered to be just that.

One of the authors of this review discussed this problem with the Zurich plumbing leaders, and they confirmed Watson's opinion that when clean pipes are used in water networks, re-contamination of ozonated water does not occur.

Even from this brief comparison of ozone with other oxidizing disinfectants, the benefits of ozone are undeniable.

Summarizing some results of an extremely brief comparison of ozone, chlorine and chlorine dioxide as an agent for cleaning and disinfecting water, we note that in a certain sense this dispute was resolved by life itself. Indeed, the experience of water treatment plants using ozone and chlorine fully testifies in favor of ozone.

1.6 Other benefits of ozone.

Due to the brevity of the review, we do not dwell here on such positive properties of ozone as the enhancement of coagulation-flocculation processes, effective impact on the microflocculation process, incomparably higher water quality in swimming pools using ozone instead of chlorine, and a number of others.

Finally, there is the issue of cost. There is an opinion that ozonation is much more expensive than chlorination. However, it is not. In the process of chlorination, it becomes necessary to remove excess chlorine from the water, to carry out the so-called dechlorination. This is usually done using special reagents. Taking into account this factor, as well as the trend of continuous price reduction for ozonation equipment and price increase for chlorine and chlorine products, the cost of these processes is currently almost comparable.

However, chlorination, if we talk about our country, is used more often than ozonation. Why? There are several reasons.

Working with chlorine, especially when it comes to bottles of liquid chlorine, is relatively simple. It is enough to unscrew the valve of the cylinder or pour a bucket of hypochlorite into the pool, and, as a first approximation, all problems with disinfection are solved. This is certainly easier than monitoring the concentration of ozone coming out of the ozonator, given that the ozonizer is a relatively complex apparatus and one must be sure that it does not suddenly turn off.

This is where the second (and maybe the first) reason for the low prevalence of ozone arises. Until very recently, the reliability of ozonation equipment left much to be desired, and the low level of automation required the use of relatively highly qualified service personnel.

In the section “Production of ozone”, we will dwell on the consideration of this problem in more detail and critically examine existing designs precisely from the angle of reliability and simplicity of equipment. Only the latest generation of Positron ozonizers allows, due to high automation and design reliability, to reduce the maintenance of ozonating equipment to a minimum, more precisely, to pressing one button.

1.7 Ozone toxicology

The toxic properties of ozone have been the subject of numerous studies since the 1940s. At this time, in Los Angeles (USA), and then in many other cities, the appearance of the so-called photochemical smog was observed. Under the influence of solar radiation, automobile emissions (hydrocarbons and nitric oxide) were transformed as a result of a complex chain of photochemical reactions into ozone and organic peroxides, including benzopyrene, a very strong carcinogen. At the same time, in some cases, the ozone concentration reached 10 MPC (≈ 1 mg/m³). Irritation of the eyes and mucous membranes of the respiratory tract has been observed in people exposed to photochemical smoke. After a certain time in the open air, the unpleasant symptoms disappeared.

Technological advances, and especially the use of catalytic converters for automotive emissions, have almost completely eliminated the causes of photochemical smog. Careful experimental studies on humans and animals have clarified quite fully the question of ozone toxicity. It can be said (in our opinion) that in a certain sense the fears about ozone toxicity are a myth. Yes, ozone is classified as a substance with the first class of danger. Its MAC is lower than that of such substances as chlorine and hydrogen cyanide (MAC for chlorine = 1 mg/m³, MAC for hydrogen cyanide = 0.3 mg/m³). The fact is that when establishing the MPC value, not only the lethal dose is taken into account, but also the vapor pressure of a given substance. Since ozone is an extremely volatile gas (Tº bp = -111 ºС), the toxicity value is high. But, it must be emphasized that for a century and a half of mankind's acquaintance with ozone, it is unknown no one case of fatal ozone poisoning. Yes, and it was not observed at all no one a case of severe ozone poisoning that would require a hospital stay. Ozone has the greatest effect on the respiratory system. Changes in respiratory rate, inhaled air volume, vital and residual lung capacity. But in the book of the Hungarian ozone specialist M. Horvath, an experiment is described in which 5 people were placed in a special chamber with a maximum exposure of 6 ppm ozone for 1 hour (6 ppm ≈ 120 MAC) and a minimum of 1.2 ppm (≈ 24 MAC) for 2.5 hours. Sense of taste, blood pressure, pulse rate were not detected. It was found that the sensation of smell was reduced, however it is not clear whether ozone affects the nervous system or "overrides" the smell of the sensor substance. There was also no change in the composition of the blood.

Experiments conducted on small animals have shown that the body becomes addicted to ozone, after which it is able to tolerate lethal doses. However, it is necessary to make an important remark about the lethal doses of ozone.

One of the authors of this review, when working with ozone, due to unforeseen circumstances, inhaled ozone at a concentration of 20-40 g / m³, which corresponds to (10-30) - 10³ ppm, and lies well above the lethal curve 4. The sensation was very unpleasant, but being in the open air completely restored normal breathing. Even if a person has a runny nose and does not smell ozone, there are now simple and reliable “ozone probes” on the market that allow you to quickly find any ozone leak.

1.8 Conclusion

Ozone, as a unique oxidizer-disinfectant, is widely used in the world, primarily in the field of drinking water treatment. In France, for example, there are several thousand water treatment plants that use ozone. Physico-chemical properties of ozone are very peculiar. It dissolves well in water, but decomposes quickly in it, especially if there are impurities of pollutants. Therefore, the lifetime, especially with a neutral pH, can vary from hours (ultrapure water) to seconds (alkaline solutions, organic impurities).

As a strong oxidizing agent (its oxidizing potential is inferior, among stable substances, only to fluorine), ozone oxidizes almost all metals, except for gold. With many substances, ozone reacts explosively. Ozone reacts with chlorine solutions in water, which is essential when these substances are used to treat water in swimming pools. Reactions with organic substances depend primarily on the nature of the organic substances. Compounds with unsaturated bonds oxidize very quickly. Other substances, like organic acids (oxalic, acetic, etc.), as well as alcohols and ketones, react very slowly. The rates of reactions with ozone in solution depend very strongly on the pH of the medium, since in an acidic environment, the molecular mechanism of oxidation is realized, where ozone itself acts, and in an alkaline environment, the OH* radical.

No less, and perhaps more valuable property of ozone is its extremely effective ability to eliminate microflora. Here it surpasses other common disinfectants (primarily chlorine) by 3-1000 times, depending on the type of pathogenic microflora. The effect of ozone on such microorganisms as fungi and algae is also detrimental, although in this case much depends on the processing conditions.

Despite these obvious advantages, in a number of industries (primarily in water treatment), chlorine and its compounds are often used instead of ozone. This is due to a number of prejudices. It is believed that the use of ozone is much more expensive than the use of chlorine. In a number of qualified comparisons of the cost indicators of ozone and chlorine treatment, when the cost of the final dechlorination process was taken into account, it was shown that the total costs are almost the same, and in some cases, when the transportation of chemical reagents is difficult or very expensive, the use of ozone is more profitable than other oxidizers-disinfectants.

True, the production of ozone itself is a technically more complex process than the production of chlorine. Previously, there were often complaints about the complexity of maintenance and reliability of ozonation equipment. Now this situation has changed for the better. The latest developments offered by the VIRIL GROUP are characterized by a high degree of automation. To turn on the ozonizer and its further operation, just press one button.

Finally, there is a preconceived notion about the extremely high toxicity of ozone gas. Indeed, for ozone there is a very low value of the maximum allowable concentration MPC = 0.1 mg/l. BUT this is primarily due to its very high volatility (ozone liquefies at -1110 C) In any case, in the 100 years of the existence of ozone, not a single serious case of ozone poisoning is known, not to mention fatal poisoning

1.9 References

Draginsky V.L., Alekseeva L.P., Samoylovich V.G. "Ozonation in water purification processes" M. Delhi print. 2007

Eng. V.V. Karaffa-Korbutt "Ozone and its application in industry and sanitation" Ed. "Education" SpP. 1912

V.F. Kozhinov, I.V. Kozhinov "Ozonation of water" M. Stroyizdat 1973

V.V. Lunin, M.P. Popovich, S.N. Tkachenko "Physical chemistry of ozone" Ed. Moscow State University 1998

Manley T.S., Negowski S.J. "Ozone" in Encyclopedic of Chemical Technology. Second Ed. Vol 14. N.J. 1967.

Chudnov A.F. The reaction of ozone with inorganic substances. Proceedings of the Kuzbass Polytechnic Institute. G. Kemerovo. 1979

HozvatsM.L. BilitzkilandHutter. Ozoneed. AkademiaKiado. Budapest.1985

Kogan B.F. et al. Handbook of solubility. T1 book 1 m.1961

Manchot E. Kampsihulte Berichte b.40 2891.1907

There. B.43.750.1910

Andreev N.I. Proceedings of the S-P Polytechnic Institute. 1908. v.9 №19 p.447

RonrebertE. DazOzone. Huttart 1916.

Krylova L.N. Physical and chemical properties of the combined technology for processing mixed copper ores from the Udokan deposit. Abstract for the degree of candidate of technical sciences. Moscow 2008

Krylova L.N. et al. “Application of ozone in hydrometallurgy. Proceedings of the first all-Russian conference "Ozone and other environmentally friendly oxidizers". 2005 Moscow, Moscow State University, building 155

Akopyan S.Z. and other Kinetics of oxidation of disulfide by ozone. Materials of the Second All-Union Conference on Ozone. Moscow, 1977, p.6

Babayan G.G. and other Demeaning of electrolytic slags of copper-chemical production with the help of ozone. p.153.

Chtyan G.S. and other Mechanism of the process of processing copper-electrolyte slags with ozone. Materials of the meeting "Chemistry and Technology of Rare Elements" Yerevan. 1978 From 122.

Semachev V.Yu. Semachev V.Yu. Development of an ozone method for cleaning flue gases from thermal power plants. Abstract of the dissertation for the degree of candidate of technical sciences. Moscow 1987

Novoselov S.S. and others. "Ozone method for cleaning flue gases." Thermal power engineering, 1986. No. 9.

Razumovsky S.D. Zamkov D.E. Ozone and its reactions with organic compounds. M. 1974

DojbidoJ. Etol. "Formation of intermediates in the process of ozonation and chlorination" Wat. Res. 1999. 33. No. 4 p3111 - 3118.

OZONE (O 3) is an allotropic modification of oxygen, its molecule consists of three oxygen atoms and can exist in all three states of aggregation. The ozone molecule has an angular structure in the form of an isosceles triangle with a vertex of 127 o . However, a closed triangle is not formed, and the molecule has a chain structure of 3 oxygen atoms with a distance between them of 0.224 nm. According to this molecular structure, the dipole moment is 0.55 debye. In the electronic structure of the ozone molecule, there are 18 electrons that form a mesomerically stable system that exists in various boundary states. The boundary ionic structures reflect the dipole nature of the ozone molecule and explain its specific reaction behavior in comparison with oxygen, which forms a radical with two unpaired electrons. The ozone molecule is made up of three oxygen atoms. The chemical formula of this gas is O 3 Ozone formation reaction: 3O 2 + 68 kcal / mol (285 kJ / mol) ⇄ 2O 3 Ozone molecular weight - 48 At room temperature, ozone is a colorless gas with a characteristic odor. The smell of ozone is felt at a concentration of 10 -7 M. In the liquid state, ozone is a dark blue color with a melting point of -192.50 C. Solid ozone is black crystals with a boiling point of -111.9 degrees C. At a temperature of 0 gr. and 1 atm. = 101.3 kPa ozone density is 2.143 g/l. In the gaseous state, ozone is diamagnetic and is pushed out of the magnetic field; in the liquid state, it is weakly paramagnetic, i.e. has its own magnetic field and is drawn into the magnetic field.

Chemical properties of ozone

The ozone molecule is unstable and, at sufficient concentrations in air under normal conditions, spontaneously turns into diatomic oxygen with the release of heat. An increase in temperature and a decrease in pressure increase the rate of ozone decomposition. The contact of ozone with even small amounts of organic substances, some metals or their oxides, sharply accelerates the transformation. The chemical activity of ozone is very high, it is a powerful oxidizing agent. It oxidizes almost all metals (with the exception of gold, platinum and iridium) and many non-metals. The reaction product is mainly oxygen. Ozone dissolves in water better than oxygen, forming unstable solutions, and the rate of its decomposition in solution is 5-8 times higher than in the gas phase than in the gas phase (Razumovsky SD, 1990). This is apparently due not to the specifics of the condensed phase, but to its reactions with impurities and the hydroxyl ion, since the decomposition rate is very sensitive to the content of impurities and pH. The solubility of ozone in sodium chloride solutions obeys Henry's law. With an increase in the concentration of NaCl in an aqueous solution, the solubility of ozone decreases (Tarunina VN et al., 1983). Ozone has a very high electron affinity (1.9 eV), which determines its properties as a strong oxidizing agent, surpassed only by fluorine (Razumovsky SD, 1990).

Biological properties of ozone and its effect on the human body

The high oxidizing ability and the fact that free oxygen radicals are formed in many chemical reactions that occur with the participation of ozone make this gas extremely dangerous for humans. How does ozone gas affect humans:

• Irritates and damages respiratory tissues;
• Affects cholesterol in human blood, forming insoluble forms, which leads to atherosclerosis;
• A long stay in an environment with a high concentration of ozone can cause male infertility.

In the Russian Federation, ozone is assigned to the first, highest hazard class of harmful substances. Ozone guidelines:

• Maximum single maximum allowable concentration (MAC m.r.) in the atmospheric air of populated areas 0.16 mg / m 3
• Average daily maximum allowable concentration (MPC d.s.) - 0.03 mg / m 3
• The maximum permissible concentration (MAC) in the air of the working area is 0.1 mg/m 3 (at the same time, the human sense of smell threshold is approximately equal to 0.01 mg/m 3).

The high toxicity of ozone, namely its ability to effectively kill mold and bacteria, is used for disinfection. The use of ozone instead of chlorine-based disinfectants can significantly reduce environmental pollution by chlorine, which is dangerous, among other things, for stratospheric ozone. Stratospheric ozone plays the role of a protective screen for all life on earth, preventing the penetration of hard ultraviolet radiation to the Earth's surface.

Harmful and beneficial properties of ozone

Ozone is present in two layers of the atmosphere. Tropospheric or ground-level ozone, located in the layer of the atmosphere closest to the Earth's surface - in the troposphere - is dangerous. It is harmful to humans and other living organisms. It has a detrimental effect on trees, crops. In addition, tropospheric ozone is one of the main "ingredients" of urban smog. At the same time, stratospheric ozone is very useful. The destruction of the ozone layer formed by it (ozone screen) leads to the fact that the flow of ultraviolet radiation to the earth's surface increases. Because of this, the number of skin cancers (including its most dangerous type, melanoma), and cases of cataracts is increasing. Exposure to hard ultraviolet weakens the immune system. Excessive UV radiation can also be a problem for agriculture, as some crops are extremely sensitive to UV light. At the same time, it should be remembered that ozone is a poisonous gas, and at the level of the earth's surface it is a harmful pollutant. In summer, due to intense solar radiation and heat, especially a lot of harmful ozone is formed in the air.

Interaction of ozone and oxygen with each other. Similarities and differences.

Ozone is an allotropic form of oxygen. Allotropy is the existence of the same chemical element in the form of two or more simple substances. In this case, both ozone (O3) and oxygen (O 2) are formed by the chemical element O. Obtaining ozone from oxygen As a rule, molecular oxygen (O 2) acts as the starting material for obtaining ozone, and the process itself is described by the equation 3O 2 → 2O 3. This reaction is endothermic and easily reversible. To shift the equilibrium towards the target product (ozone), certain measures are applied. One way to produce ozone is by using an arc discharge. The thermal dissociation of molecules increases sharply with increasing temperature. Thus, at T=3000K, the content of atomic oxygen is ~10%. A temperature of several thousand degrees can be obtained using an arc discharge. However, at high temperatures, ozone decomposes faster than molecular oxygen. To prevent this, the equilibrium can be shifted by first heating the gas and then abruptly cooling it. Ozone in this case is an intermediate product during the transition of a mixture of O 2 + O to molecular oxygen. The maximum concentration of O 3 that can be obtained with this method of production reaches 1%. This is sufficient for most industrial purposes. Oxidizing properties of ozone Ozone is a powerful oxidizing agent, much more reactive than diatomic oxygen. Oxidizes almost all metals and many non-metals with the formation of oxygen: 2 Cu 2+ (aq) + 2 H 3 O + (aq) + O 3 (g) → 2 Cu 3+ (aq) + 3 H 2 O (1) + O 2 (g) Ozone can participate in combustion reactions, the combustion temperature is higher than when burning in an atmosphere of diatomic oxygen: 3 C 4 N 2 + 4 O 3 → 12 CO + 3 N 2 The standard ozone potential is 2.07 V, therefore the ozone molecule is unstable and spontaneously turns into oxygen with the release of heat. At low concentrations, ozone decomposes slowly, at high concentrations - with an explosion, because its molecule has excess energy. Heating and contact of ozone with negligible amounts of organic substances (hydroxides, peroxides, metals of variable valence, their oxides) sharply accelerates the transformation. On the contrary, the presence of small amounts of nitric acid stabilizes ozone, and in vessels made of glass and some plastics or pure metals, ozone practically decomposes at -78 0 C. The affinity of ozone for an electron is 2 eV. Only fluorine and its oxides have such a strong affinity. Ozone oxidizes all metals (with the exception of gold and platinum), as well as most other elements. Chlorine reacts with ozone to form hypochlore OCL. The reactions of ozone with atomic hydrogen are the source of the formation of hydroxyl radicals. Ozone has an absorption maximum in the UV region at a wavelength of 253.7 nm with a molar extinction coefficient: E = 2.900 Based on this, UV photometric determination of ozone concentration together with iodometric titration is accepted as international standards. Oxygen, unlike ozone, does not react with KI.

Solubility of ozone and its stability in aqueous solutions

The rate of ozone decomposition in solution is 5-8 times higher than in the gas phase. The solubility of ozone in water is 10 times higher than that of oxygen. According to different authors, the solubility coefficient of ozone in water ranges from 0.49 to 0.64 ml of ozone/ml of water. Under ideal thermodynamic conditions, the equilibrium obeys Henry's law, i.e. the concentration of a saturated gas solution is proportional to its partial pressure. C S = B × d × Рi where: С S is the concentration of a saturated solution in water; d is the mass of ozone; Pi is the partial pressure of ozone; B is the dissolution coefficient; The fulfillment of Henry's law for ozone as a metastable gas is conditional. The decay of ozone in the gas phase depends on the partial pressure. In the aquatic environment, processes that go beyond the scope of Henry's law take place. Instead, under ideal conditions, the Gibs-Dukem-Margulesdu law applies. In practice, it is customary to express the solubility of ozone in water in terms of the ratio of ozone concentration in a liquid medium to the ozone concentration in the gas phase: Ozone saturation depends on temperature and water quality, since organic and inorganic impurities change the pH of the medium. Under the same conditions in tap water, the concentration of ozone is 13 mg/l, in bidistilled water - 20 mg/l. The reason for this is the significant decay of ozone due to various ionic impurities in drinking water.

Ozone decay and half-life (t 1/2)

In the aquatic environment, ozone decay strongly depends on water quality, temperature and pH of the environment. An increase in the pH of the medium accelerates the decay of ozone and, at the same time, reduces the concentration of ozone in water. Similar processes occur with increasing temperature. The half-life of ozone in bidistilled water is 10 hours, in demineralized water - 80 minutes; in distilled water - 120 minutes. It is known that the decomposition of ozone in water is a complex process of reactions of radical chains: The maximum amount of ozone in the water sample is observed within 8-15 minutes. After 1 hour, only free oxygen radicals are observed in the solution. Among them, the most important is the hydroxyl radical (OH') (Staehelin G., 1985), and this must be taken into account when using ozonized water for therapeutic purposes. Since ozonized water and ozonized saline are used in clinical practice, we evaluated these ozonized liquids depending on the concentrations used in domestic medicine. The main methods of analysis were iodometric titration and intensity of chemiluminescence using a biochemiluminometer device BKhL-06 (manufactured by Nizhny Novgorod) (Kontorshchikova K.N., Peretyagin S.P., Ivanova I.P. 1995). The phenomenon of chemiluminescence is associated with recombination reactions of free radicals formed during the decomposition of ozone in water. When processing 500 ml of bi- or distilled water by bubbling with an ozone-oxygen gas mixture with an ozone concentration in the range of 1000-1500 μg/l and a gas flow rate of 1 l/min for 20 minutes, chemiluminescence is detected within 160 minutes. Moreover, in bidistilled water, the luminescence intensity is significantly higher than in distilled water, which is explained by the presence of impurities that quench the luminescence. The solubility of ozone in NaCl solutions obeys Henry's law, i.e. decreases with increasing salt concentration. The physiological solution was treated with ozone at a concentration of 400, 800 and 1000 μg/l for 15 minutes. The total glow intensity (in mv) increased with increasing ozone concentration. The glow duration is 20 minutes. This is due to the faster recombination of free radicals and hence the quenching of the glow due to the presence of impurities in the physiological solution. Despite the high oxidizing potential, ozone has a high selectivity, which is due to the polar structure of the molecule. Compounds containing free double bonds (-C=C-) instantly react with ozone. As a result, unsaturated fatty acids, aromatic amino acids and peptides, especially those containing SH groups, are sensitive to ozone. According to Krige (1953) (quoted from Vieban R. 1994), the primary product of the interaction of the ozone molecule with bioorganic substrates is a 1-3 dipolar molecule. This reaction is the main one in the interaction of ozone with organic substrates at pH< 7,4. Озонолиз проходит в доли секунды. В растворах скорость этой реакции равна 105 г/моль·с. В первом акте реакции образуется пи-комплекс олефинов с озоном. Он относительно стабилен при температуре 140 0 С и затем превращается в первичный озонид (молозонид) 1,2,3-триоксалан. Другое возможное направление реакции — образование эпоксидных соединений. Первичный озонид нестабилен и распадается с образованием карбоксильного соединения и карбонилоксида. В результате взаимодействия карбонилоксида с карбонильным соединением образуется биполярный ион, который затем превращается во вторичный озонид 1,2,3 — триоксалан. Последний при восстановлении распадается с образованием смеси 2-х карбонильных соединений, с дальнейшим образованием пероксида (I) и озонида (II). Ozonation of aromatic compounds proceeds with the formation of polymeric ozonides. The addition of ozone breaks the aromatic conjugation in the nucleus and requires energy, so the rate of ozonation of homologues correlates with the conjugation energy. The ozonation of dried hydrocarbons is associated with the introduction mechanism. Ozonation of sulfur- and nitrogen-containing organic compounds proceeds as follows: Ozonides are usually poorly soluble in water, but good in organic solvents. When heated, the action of transition metals decompose into radicals. The amount of ozonides in an organic compound is determined by the iodine number. The iodine number is the mass of iodine in grams added to 100 g of organic matter. Normally, for fatty acids, the iodine number is 100-400, for solid fats 35-85, for liquid fats - 150-200. For the first time, ozone as an antiseptic agent was tested by A. Wolff back in 1915 during the First World War. Over the following years, information about the successful use of ozone in the treatment of various diseases gradually accumulated. However, for a long time, only ozone therapy methods were used, associated with direct contacts of ozone with external surfaces and various body cavities. Interest in ozone therapy increased with the accumulation of data on the biological effect of ozone on the body and the emergence of reports from various clinics around the world about the successful use of ozone in the treatment of a number of diseases. The history of the medical use of ozone begins in the 19th century. The pioneers of the clinical use of ozone were Western scientists in America and Europe, in particular, C. J. Kenworthy, B. Lust, I. Aberhart, E. Payer, E. A. Fisch, N. N. Wolff and others. Little was known about the therapeutic use of ozone in Russia. Only in the 60-70s, several works on inhalation ozone therapy and on the use of ozone in the treatment of certain skin diseases appeared in the domestic literature, and since the 80s in our country this method has been intensively developed and more widely used. The foundations for the fundamental development of ozone therapy technologies were largely determined by the work of the Institute of Chemical Physics of the USSR Academy of Medical Sciences. The book "Ozone and its reactions with organic substances" (S. D. Razumovsky, G. E. Zaikov, Moscow, 1974) was the starting point for substantiating the mechanisms of the therapeutic effect of ozone by many developers. The International Ozone Association (IOA), which has held 20 international congresses, is widely active in the world, and since 1991, our doctors and scientists have also taken part in these congresses. Today, the problems of the applied use of ozone, namely in medicine, are considered in a completely new way. In the therapeutic range of concentrations and doses, ozone exhibits the properties of a powerful bioregulator, an agent that can largely enhance the methods of traditional medicine, and often act as a monotherapy agent. The use of medical ozone is a qualitatively new solution to urgent problems in the treatment of many diseases. Ozone therapy technologies are used in surgery, obstetrics and gynecology, dentistry, neurology, therapeutic pathology, infectious diseases, dermatology and venereal diseases and a number of other diseases. Ozone therapy is characterized by ease of execution, high efficiency, good tolerability, the practical absence of side effects, and it is cost-effective. The therapeutic properties of ozone in diseases of various etiologies are based on its unique ability to influence the body. Ozone in therapeutic doses acts as an immunomodulating, anti-inflammatory, bactericidal, antiviral, fungicidal, cytostatic, anti-stress and analgesic agent. Its ability to actively correct disturbed oxygen homeostasis of the body opens up great prospects for restorative medicine. A wide range of methodological possibilities makes it possible to use the healing properties of ozone with great efficiency for local and systemic therapy. In recent decades, methods associated with parenteral (intravenous, intramuscular, intraarticular, subcutaneous) administration of therapeutic doses of ozone have come to the fore, the therapeutic effect of which is associated mainly with the activation of various vital systems of the body. Oxygen-ozone gas mixture at high (4000 - 8000 µg/l) ozone concentrations in it is effective in the treatment of heavily infected, poorly healing wounds, gangrene, bedsores, burns, fungal skin lesions, etc. Ozone in high concentrations can also be used as a hemostatic agent. Low concentrations of ozone stimulate reparation, promote epithelialization and healing. In the treatment of colitis, proctitis, fistulas and a number of other intestinal diseases, rectal administration of an oxygen-ozone gas mixture is used. Ozone dissolved in saline is successfully used in peritonitis for the sanitation of the abdominal cavity, and ozonized distilled water in jaw surgery, etc. Ozone dissolved in saline or in the patient's blood is used for intravenous administration. The pioneers of the European School postulated that main goal of ozone therapy is: "The stimulation and reactivation of oxygen metabolism without disturbing the redox systems" - this means that when calculating dosages for a session or course, the ozone therapeutic effect should be within the limits in which radical oxygen metabolites or excess peroxide are enzymatically aligned "(Z Rilling, R. Fiban 1996 in book. The practice of ozone therapy). In foreign medical practice, for parenteral administration of ozone, mainly large and small autohemotherapy are used. When carrying out a large autohemotherapy, the blood taken from the patient is thoroughly mixed with a certain volume of oxygen-ozone gas mixture, and immediately drip is injected back into the vein of the same patient. With a small autohemotherapy, ozonized blood is injected intramuscularly. The therapeutic dose of ozone in this case is maintained due to fixed volumes of gas and ozone concentration in it.

Scientific achievements of domestic scientists began to be regularly reported at international congresses and symposiums

• 1991 - Cuba, Havana,
• 1993 - USA San Francisco,
• 1995 - France Lille,
• 1997 - Japan, Kyoto,
• 1998 - Austria, Salzburg,
• 1999 – Germany, Baden-Baden,
• 2001 - England, London,
• 2005 - France, Strasbourg,
• 2009 - Japan, Kyoto,
• 2010 - Spain, Madrid
• 2011 Turkey (Istanbul), France (Paris), Mexico (Cancun)
• 2012 - Spain Madrid

Clinics in Moscow and Nizhny Novgorod have become scientific centers for the development of ozone therapy in Russia. Very soon they were joined by scientists from Voronezh, Smolensk, Kirov, Novgorod, Yekaterinburg, Saransk, Volgograd, Izhevsk and other cities. The spread of ozone therapy technologies certainly contributed to the regular holding of All-Russian scientific and practical conferences with international participation, organized on the initiative of the Association of Russian Ozone Therapists since 1992 in Nizhny Novgorod, gathering specialists from all over the country.

All-Russian scientific and practical conferences with international participation on ozone therapy

I - "OZONE IN BIOLOGY AND MEDICINE" - 1992., N.Novgorod II - "OZONE IN BIOLOGY AND MEDICINE" - 1995., N.Novgorod III - "OZONE AND METHODS OF EFFERENT THERAPY" - 1998., N.Novgorod IV - "OZONE AND METHODS OF EFFERENT THERAPY" - 2000., N.Novgorod V - "OZONE IN BIOLOGY AND MEDICINE" - 2003., N.Novgorod VI - "OZONE IN BIOLOGY AND MEDICINE" - 2005., N.Novgorod“I Conference on Ozone Therapy of the Asian-European Union of Ozone Therapists and Manufacturers of Medical Equipment”– 2006., Bolshoe Boldino, Nizhny Novgorod Region VII - "OZONE IN BIOLOGY AND MEDICINE" - 2007., N.Novgorod U111 – "Ozone, reactive oxygen species and methods of intensive care in medicine" - 2009, Nizhny Novgorod By 2000, the Russian school of ozone therapy finally formed its own, different from the European, approach to the use of ozone as a therapeutic agent. The main differences are the widespread use of physiological saline as an ozone carrier, the use of significantly lower concentrations and doses of ozone, the developed technologies for extracorporeal processing of large volumes of blood (ozonized cardiopulmonary bypass), individual choice of doses and concentrations of ozone in systemic ozone therapy. The desire of the majority of Russian doctors to use the lowest effective concentrations of ozone reflects the basic principle of medicine - "do no harm." The safety and effectiveness of Russian methods of ozone therapy has been repeatedly substantiated and proven in relation to various fields of medicine. As a result of many years of fundamental clinical research, scientists from Nizhny Novgorod established an unknown regularity in the formation of adaptive mechanisms of the body of mammals under systemic exposure to low therapeutic doses of ozone, which consists in the fact that the trigger is the effect of ozone on the pro- and antioxidant balance of the body and is due to a moderate intensification of free- radical reactions, which, in turn, increases the activity of the enzymatic and non-enzymatic components of the antioxidant defense system ”(Kontorshchikova K.N., Peretyagin S.P.), for which the authors received a discovery (Diploma No. 309 dated May 16, 2006). In the works of domestic scientists, new technologies and aspects of the use of ozone for therapeutic purposes have been developed:

• Widespread use of saline solution (0.9% NaCl solution) as a carrier of dissolved ozone
• The use of relatively low concentrations and doses of ozone for systemic exposure (intravascular and intra-intestinal administration)
• Intraosseous infusions of ozonated solutions
• Intracoronary administration of ozonated cardioplegic solutions
• Total extracorporeal ozone treatment of large volumes of blood during cardiopulmonary bypass
• Low flow ozone therapy
• Intraportal administration of ozonized solutions
• The use of ozone in the theater of operations
• Accompanying systemic ozone therapy with biochemical control methods

In 2005-2007 for the first time in world practice in Russia, ozone therapy received official status at the state level in the form of approval by the Ministry of Health and Social Development of the Russian Federation of new medical technologies for the use of ozone in dermatology and cosmetology, obstetrics and gynecology, and traumatology. Currently, active work is underway in our country to disseminate and introduce the method of ozone therapy. Analysis of the Russian and European experience of ozone therapy allows us to draw important conclusions:

1. Ozone therapy is a non-drug method of therapeutic effect that allows obtaining positive results in pathology of various origins.
2. The biological effect of parenterally administered ozone is manifested at the level of low concentrations and doses, which is accompanied by clinically pronounced positive therapeutic effects that have a clearly defined dose-dependence.
3. The experience of the Russian and European schools of ozone therapy shows that the use of ozone as a therapeutic agent significantly increases the effectiveness of drug therapy, and in some cases makes it possible to replace or reduce the pharmacological burden on the patient. Against the background of ozone therapy, the patient's own oxygen-dependent reactions and processes of the diseased organism are restored.
4. The technical capabilities of modern medical ozonizers with ultra-precise dosing capabilities allow the use of ozone in the range of low therapeutic concentrations similar to conventional pharmacological agents.

7. What determines the required water treatment time?

Ozone ability dissolve in water depends on temperature

water and the area of ​​contact of gases with water.

The colder the water and smaller divider size,

the less ozone will be dissolved. The higher the water temperature,

the faster the ozone decomposes to oxygen and is lost through evaporation.

Depending on the degree water pollution

greater or lesser concentrations of ozone are needed.

8. Is additional filtration necessary?

water after ozonation?

If the water contained a large number of

complex compounds, then as a result of processing

ozone in it various precipitations fall out.

Such water is necessary additional filtering.

For this filtering, you can use the most simple and

cheap filters.

At the same time, the resource their work will be greatly extended.

9. Should I be afraid of a long time

water treatment with ozone?

Water treatment too much ozone

does not lead to detrimental effects.

The gas quickly turns into oxygen,

which only improves water quality.

10. What is the indicator of acidity of water,

passed ozonation?

Water has weakly alkaline reaction PH = 7.5 - 9.0.

11. How much content increases

oxygen in water after ozonation?

Oxygen content in water increases by 14 - 15 times.

12. How quickly does ozone decay in air, in water?

In the air after 10 minutes. ozone concentration decreases

by half, forming oxygen and water.

In cold water after 15-20 min. ozone decays

by half, forming a hydroxyl group and water.

13. Why is it good to drink oxygenated water?

Increases consumption glucose in tissues and organs

Increases satiety blood plasma oxygen

Reduces the degree oxygen starvation

Improves blood microcirculation.

Renders positive action

on the metabolism of the liver and kidneys.

Keeps working heart muscle.

Decreases frequency breathing and

Increases respiratory volume.

14. How long does it take to ozonize water?

The richer water impurities,

the longer the processing time.

So, for example, ozonation of 3 liters of tap water

takes 10 - 15 min.

The same volume of water taken from the reservoir

depending on the season of the year and the level of pollution

should be carried out three to four times longer.

15. What is the best way to ozonize water in a bowl or jar?

The dishes are better to choose glass with tapering

throat (jar) to create greater concentration

ozone to a limited extent.

16. When is the best time to process water for tea?

before or after boiling?

For brewing tea water is not recommended

bring to the boil.

The best t \u003d 85-90 ° C.

Water treatment is carried out before heating.

17. Is it possible to ozonize mineral water?

In such water are stored all minerals,

it becomes safe and oxygenated.

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