Ozone (chemical element): properties, formula, designation. Methods for obtaining ozone. Ozone (O3) is a triatomic modification of oxygen (O2)

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 g.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 at normal conditions spontaneously turns into diatomic oxygen with the release of heat. Increasing temperature and decreasing 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

High oxidizing power and the fact that in many chemical reactions, flowing with the participation of ozone, free oxygen radicals are formed, making 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.

AT Russian Federation ozone is classified as 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 (ozone screen) formed by it 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 crops of some crops are extremely sensitive to ultraviolet radiation. 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 in the air, especially a lot of harmful ozone is formed.

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

Ozone - allotropic form 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 producing 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, it decomposes explosively, 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 of him in ideal conditions Gibs-Dukem-Margulesdu law applies. In practice, it is customary to express the solubility of ozone in water through the ratio of the 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 a 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). Озонирование ароматических соединений протекает с образованием полимерных озонидов. Присоединение озона нарушает ароматическое сопряжение в ядре и требует затрат энергии, поэтому скорость озонирования гомологов коррелирует с энергией сопряжения. Озонирование насушенных углеводородов связано с механизмом внедрения. Озонирование серо- и азотосодержащих органических соединений протекает следующим образом: Озониды обычно плохо растворимы в воде, но хорошо в органических растворителях. При нагревании, действии переходных металлов распадаются на радикалы. Количество озонидов в органическом соединении определяется йодным числом. Йодное число — масса йода в граммах, присоединяющееся к 100 г органического вещества. В норме для жирных кислот йодное число составляет 100-400, для твердых жиров 35-85, для жидких жиров — 150-200. Впервые озон, как антисептическое средство был опробован A. Wolff еще в 1915 во время первой мировой войны. Последующие годы постепенно накапливалась информация об успешном применении озона при лечении различных заболеваний. Однако long time only methods of ozone therapy 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, a tool that can greatly enhance the methods traditional medicine and often act as a monotherapy. The use of medical ozone represents a qualitatively new solution actual problems 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 simplicity of execution, high efficiency, good tolerability, the practical absence of side effects, 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. Wide spectrum methodological possibilities allows to use with great efficiency medicinal properties ozone 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 mainly associated 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 for sanitation of peritonitis abdominal cavity, and ozonized distilled water in jaw surgery, etc. For intravenous administration, ozone is used, dissolved in saline or in the patient's blood. 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,” which 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. Main differences - wide use physiological saline as an ozone carrier, the use of significantly lower concentrations and doses of ozone, developed technologies for extracorporeal treatment of large volumes of blood (ozonized cardiopulmonary bypass), individual choice of doses and concentrations of ozone in systemic ozone therapy. In the desire of most Russian doctors to use the smallest of effective concentrations ozone reflected the basic principle of medicine - "do no harm". The safety and effectiveness of Russian ozone therapy methods have been repeatedly substantiated and proven in relation to various areas medicine. As a result of many years of fundamental clinical research by Nizhny Novgorod scientists, “an unknown regularity in the formation of adaptive mechanisms of the body of mammals under systemic exposure to low therapeutic doses of ozone has been established, 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 on 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:

Ozone therapy is a non-drug method of therapeutic effect that allows obtaining positive results in pathology of various origins.
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 pronounced dose-dependence.
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.
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.

Have you ever noticed how pleasant it is to breathe after the rain? This refreshing air is provided by the ozone in the atmosphere that comes after rain. What is this substance, what are its functions, formula, and is it really useful for the human body? Let's figure it out.

What is ozone?

To everyone who has studied high school, it is known that the oxygen molecule consists of two atoms of the chemical element oxygen. However, this element is able to form another chemical compound - ozone. This name is given to a substance that, as a rule, occurs in the form of a gas (although it can exist in all three states of aggregation).

The molecule of this substance is quite similar to oxygen (O 2), but it does not consist of two, but of three atoms - O 3.

History of the discovery of ozone

The man who first synthesized ozone is the Dutch physicist Martin Van Marum.

It was he who in 1785 conducted an experiment by passing an electric discharge through the air. The resulting gas not only acquired a specific smell, but also a bluish tint. In addition, the new substance turned out to be a stronger oxidizing agent than ordinary oxygen. So, having considered its effect on mercury, Van Marum found that the metal changed its physical properties, which did not happen to him under the influence of oxygen.

Despite his discovery, the Dutch physicist did not believe that ozone was a special substance. Only 50 years after the discovery of Van Marum, the German scientist Christian Friedrich Schönbein became seriously interested in ozone. It was thanks to him that this substance got its name - ozone (after the Greek word meaning "smell"), and was also more closely studied and described.

Ozone: physical properties

This substance has a number of properties. The first of these is the ability of ozone, like water, to exist in three states of aggregation.

The normal state in which ozone resides is a bluish gas (it is he who paints the sky azure) with a noticeable metallic aroma. The density of such a gas is 2.1445 g/dm³.

When the temperature drops, ozone molecules form a blue-violet liquid with a density of 1.59 g/cm³ (at -188 °C). Boils liquid O 3 at -111.8 ° C.

When in a solid state, ozone darkens, becoming almost black with a distinct violet-blue reflection. Its density is 1.73 g / cm 3 (at −195.7 ° С). The temperature at which solid ozone begins to melt is −197.2 °C.

The molecular weight of O 3 is 48 daltons.

At a temperature of 0 °C, ozone dissolves perfectly in water, ten times faster than oxygen. The presence of impurities in water can further accelerate this reaction.

In addition to water, ozone dissolves in freon, which facilitates its transportation.

Among other substances in which it is easy to dissolve O 3 (in a liquid state of aggregation) are argon, nitrogen, fluorine, methane, carbon dioxide, carbon tetrachloride.

It also mixes well with liquid oxygen (at a temperature of 93 K).

Chemical properties of ozone

The O 3 molecule is rather unstable. For this reason, in normal condition it exists for 10-40 minutes, after which it decomposes, forming a small amount of heat and oxygen O 2. This reaction can occur and much faster if an increase in ambient temperature or a decrease in temperature act as catalysts. atmospheric pressure. Also, the decomposition of ozone is facilitated by its contact with metals (except gold, platinum and iridium), oxides or substances of organic origin.

Interaction with nitric acid stops the decomposition of O 3. This is also facilitated by the storage of the substance at a temperature of -78 ° C.

The main chemical property of ozone is its oxidizability. One of the products of oxidation is always oxygen.

Under different conditions, O 3 is able to interact with almost all substances and chemical elements, reducing their toxicity by turning them into less dangerous ones. For example, cyanides are oxidized to cyanates, which are much safer for biological organisms.

How are they mined?

Most often, for the extraction of O 3, oxygen is affected by an electric current. To separate the resulting mixture of oxygen and ozone, the property of the latter is used to liquefy better than O 2 .

In chemical laboratories, sometimes O 3 is produced by the reaction of a cooled sulfuric acid concentrate with barium peroxide.

In medical institutions that use O 3 to improve patients, this substance is obtained by irradiating O 2 with ultraviolet light (by the way, this substance is formed in the same way in the Earth's atmosphere under the action of sunlight).

The use of O3 in medicine and industry

The simple structure of ozone, availability source material for its extraction contributes to the active use of this substance in industry.

Being a strong oxidizing agent, it is able to disinfect much better than chlorine, formaldehyde or ethylene oxide, while being less toxic. Therefore, O 3 is often used for sterilization medical instruments, equipment, forms, as well as many preparations.

In industry, this substance is most often used for the purification or extraction of many chemicals.

Another branch of use is the bleaching of paper, fabrics, mineral oils.

In the chemical industry, O 3 not only helps to sterilize equipment, tools and containers, but is also used to disinfect the products themselves (eggs, grains, meat, milk) and increase their shelf life. In fact, it is considered one of the best food preservatives because it is non-toxic and non-carcinogenic, and it is also excellent at killing mold spores and other fungi and bacteria.

In bakeries, ozone is used to speed up the yeast fermentation process.

Also, with the help of O 3, cognacs are artificially aged, and fatty oils are refined.

How does ozone affect the human body?

Because of this similarity with oxygen, there is a misconception that ozone is a substance that is beneficial to the human body. However, this is not the case, since O 3 is one of the strongest oxidizing agents that can destroy the lungs and kill anyone who inhales this gas excessively. No wonder the state environmental organizations in every country strictly monitor the concentration of ozone in the atmosphere.

If ozone is so bad, why does it always make it easier to breathe after rain?

The fact is that one of the properties of O 3 is its ability to kill bacteria and purify substances from harmful impurities. When it rains, ozone begins to form due to a thunderstorm. This gas affects the toxic substances contained in the air, splitting them, and purifies oxygen from these impurities. It is for this reason that the air after rain is so fresh and pleasant, and the sky takes on a beautiful azure color.

These chemical properties of ozone, which allow it to purify the air, have recently been actively used to treat people suffering from various respiratory diseases, as well as to purify air, water, and various cosmetic procedures.

Quite actively today, household ozonizers are advertised that purify the air in the house with the help of this gas. Although this technique seems to be very effective, scientists have not yet studied the effect of a large number ozone-purified air on the body. For this reason, you should not get too carried away with ozonation.

It is customary to distinguish between two types of ozone:

- tropospheric ozone , formed in the lower layers of the Earth's atmosphere below 8-12 km. Tropospheric ozone accounts for about 10% of all atmospheric ozone.

- stratospheric ozone , formed in the upper layers of the Earth's atmosphere above 12 km.

Atmospheric ozone concentration very insignificant: up to one thousandth of a percent of the total volume of the Earth's atmosphere (up to 0.001%).

The ozone layer (ozonosphere) is the region of the Earth's atmosphere in which ozone is actively formed. The ozonosphere begins at a level of 10-12 km from the Earth's surface and extends to altitudes of 50-55 km, but most of the ozone is found at an altitude of about 25 km.

However, even in the zone of greatest ozone concentrations in the atmosphere there are no more than 5-10 ozone molecules per million air molecules.

If you collect all the ozone contained in the vertical column of the atmosphere at a pressure of 760 mm Hg. Art. and a temperature of 0°C, you get a layer with a thickness of only 3 mm.

At various conditions the amount of ozone in the atmosphere can vary by about 2 times, so that the height of a homogeneous ozone atmosphere can be either 0.2 or 0.4 cm.

The concentration of ozone in the atmosphere and the distribution of the ozone layer above the Earth's surface.

The ozonosphere covers the entire planet, but the distribution of the ozone layer over the Earth's surface is uneven. The formation of most of the ozone occurs above the equator, and towards the poles O 3 is carried by air currents. But if we look at the map of the distribution of the ozone layer over the latitudes of the Earth, we will see that just above the equatorial latitudes, the ozone content in the atmosphere is minimal.

On the planet, a tropical region of insufficient ozone content is clearly distinguished in the zone from 35 ° N. sh. up to 35°S sh., where the average reduced thickness of the O 3 layer is about 0.26 cm. To the north and south of it, the layer thickness is greater - 0.35 cm. That is, the thickness of the ozone layer (ozone concentration in the atmosphere) increases towards the poles.

The amount of ozone is relatively large in the northern polar latitudes, then decreases to the south, and is relatively small in the area between 35 N. latitude. and 35 south latitude, then increases, and the secondary maximum falls on 50 - 60 south latitude. A new "failure" is planned over Antarctica.

The highest concentration of ozone in the atmosphere occurs at the following latitudes:

In the Northern Hemisphere at latitude 65-75°

In the southern hemisphere at latitude 50-60°

Why is this happening?

Why is the ozone layer thinner over the equator, the concentration of ozone in the atmosphere is less?

After all, it would seem quite logical to assume that there should be more ozone where it is formed. There are several reasons to explain this phenomenon. Let's consider them in more detail.

The reason for the low concentration of ozone over the equatorial latitudes is the rapid decay of the ozone molecule. The lifetime of an ozone molecule here is only a few hours.

This is primarily due to the high intensity of solar radiation in the high layers of the atmosphere at equatorial latitudes. Ultraviolet radiation breaks down ozone molecules, and ozone is also destroyed by reaction with atomic oxygen.

The remaining ozone, due to its greater density, sinks into the lower layers of the atmosphere and is transported by air currents towards the Earth's poles. Here, the lifetime of the ozone molecule is already much higher - about 100 days.

Thus, the concentration of ozone in the atmosphere over the equator is lower than over the polar latitudes.

This rule (increase in ozone concentration from tropical to polar regions and from higher to lower layers) is called the Dutsch–Dobson and Dobson–Normand principles, respectively.

2. The concentration of ozone in the atmosphere depending on the season.

In the previous paragraph, we considered the change in the concentration of ozone in the atmosphere depending on geographical latitude. But the ozone concentration is also affected by the time of year. This is especially noticeable in the polar latitudes; in the middle latitudes, the maximum (0.43 cm) occurs in March, and the minimum (0.27 cm) occurs in October.

In general, regardless of latitude, the maximum ozone content in the atmosphere occurs at the end of winter and spring, and the minimum occurs in autumn and the beginning of winter. But with the advance to the north and south, the onset of the maximum is pushed back to later months. For example, in Alma-Ata, the maximum thickness of the ozone layer is observed in February, in St. Petersburg - in March, on about. Dixon - in May.

The maximum value of ozone concentration in the atmosphere, registered on the globe, is 0.76 cm (this record value was recorded on Kerguelen Island on October 20, 1967), and the minimum value (in "ozone holes"") is 0.09 cm.

3. The concentration of ozone in the atmosphere depending on the time of day.

The concentration of ozone in the atmosphere can change more or less randomly during the day and the amplitude of these changes is comparable to the amplitude of latitudinal and seasonal variations.

The diurnal variations in ozone can be very large. So, at the ozonometric station on Kerguelen Island in 1968, the following data were obtained: March 22 - 0.583 cm; March 23 - 0.749 cm; March 25 - 0.283 cm.

It was an article about the concentration of ozone in the Earth's atmosphere and the boundaries of the ozone layer. Read more:The value of the ozone layer of the Earth - the ozonosphere. The impact of ultraviolet rays of the sun on humans and other living organisms.

Ozone is a gas of natural origin, which, being in the stratosphere, protects the population of the planet from the negative effects ultraviolet rays. In medicine, this substance is often used to stimulate hematopoiesis and increase immunity. At the same time, with the natural formation of ozone in the troposphere as a result of the interaction of direct sunlight and exhaust gases, its effect on human body opposite. Inhalation of air with an increased concentration of gas can lead not only to an exacerbation of allergic reactions, but also to the development of neurological disorders.

Characteristics of ozone

Ozone is a gas composed of three oxygen atoms. In nature, it is formed as a result of the action of direct sunlight on atomic oxygen.

Depending on the shape and temperature, the color of ozone can vary from light blue to dark blue. The connection of molecules in this gas is very unstable - a few minutes after the formation, the substance decomposes into oxygen atoms.

Ozone is a strong oxidizing agent, due to which it is often used in industry, rocket science, and medicine. Under production conditions, this gas is present during welding, water electrolysis procedures, and the manufacture of hydrogen peroxide.

Answering the question whether ozone is poisonous or not, experts give an affirmative answer. This gas belongs to the highest toxicity class, which corresponds to many chemical warfare agents, including hydrocyanic acid.

The effect of gas on a person

In the course of numerous studies, scientists have come to the conclusion that the effect of ozone on the human body depends on how much gas enters the lungs along with air. The following maximum allowable concentrations of ozone have been established by the World Health Organization:

in the residential area - up to 30 μg / m 3;
in the industrial area - no more than 100 mcg / m 3.

A single maximum dosage of the substance should not exceed 0.16 mg / m 3.

Negative influence

The negative effects of ozone on the body are often observed in people who have to deal with this gas in a production environment: specialists in the rocket industry, workers using ozonizers and ultraviolet lamps.

Long-term and regular exposure to ozone on a person leads to the following consequences:

irritation of the respiratory system;
development of asthma;
respiratory depression;
increased risk of developing allergic reactions;
increase the possibility of developing male infertility;
decreased immunity;
growth of carcinogenic cells.

Ozone most actively affects four groups of people: children, persons with hypersensitivity, outdoor athletes and the elderly. In addition, the risk zone includes patients with chronic pathologies of the respiratory and cardiovascular systems.

As a result of contact under industrial conditions with liquid ozone, which crystallizes at a temperature of -200 degrees Celsius, deep frostbite may occur.

positive impact

The maximum amount of ozone is found in the stratospheric layer of the planet's air envelope. The ozone layer located there contributes to the absorption of the most harmful part of the ultraviolet rays of the solar spectrum.

In carefully adjusted dosages, medical ozone or an oxygen-ozone mixture has a beneficial effect on the human body, due to which it is often used for medicinal purposes.

Under the supervision of the attending physician, the use of this substance allows you to achieve the following results:

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eliminate oxygen deficiency;
enhance the redox processes occurring in the body;
reduce the effects of intoxication by removing toxins;
eliminate pain syndrome;
improve blood flow and ensure blood supply to all organs;
restore the proper functioning of the liver in its various diseases, including hepatitis.

In addition, the use of ozone therapy in medical practice can improve the general condition of the patient: stabilize sleep, reduce nervousness, increase immunity, and eliminate chronic fatigue.

Due to its ability to oxidize other chemical elements, ozone is often used as a disinfectant. This substance allows you to effectively fight fungi, viruses and bacteria.

The use of ozonizers

The described positive properties of ozone have led to the production and use in industrial and domestic conditions of ozonizers - devices that produce trivalent oxygen.

The use of such devices in industry allows you to carry out the following activities:

disinfect the air in the room;
destroy mold and fungi;
disinfect water and sewage;

In medical institutions, ozonizers are used for disinfection of premises, sterilization of instruments and consumables.

The use of ozonizers is common at home. Such devices are often used to enrich the air with oxygen, disinfect water, and eliminate viruses and bacteria from dishes or household items used by a person with an infectious disease.

When using an ozonator in everyday life, all conditions specified by the manufacturer of the device must be observed. It is strictly forbidden to be indoors when the device is turned on, as well as immediately drink water purified with it.

Symptoms of poisoning

The penetration of a high concentration of ozone into the human body through the respiratory organs or prolonged interaction with this substance can cause severe intoxication. Symptoms of ozone poisoning can appear both sharply - with a single inhalation of a large amount of this substance, and can be detected gradually - with chronic intoxication due to non-compliance with working conditions or rules of use. household ozonizers.

The first signs of poisoning from the respiratory system are detected:

perspiration and burning in the throat;
shortness of breath, shortness of breath;
inability to take a deep breath;
the appearance of frequent and intermittent breathing;
pain in the chest area.

When exposed to gas on the eyes, their tearing, the occurrence of pain, redness of the mucous membrane, and vasodilation can be observed. In some cases, deterioration or complete loss of vision occurs.

With systematic contact, ozone can affect the human body in the following ways:

structural transformations of the bronchi occur;
various diseases of the respiratory tract develop and worsen: pneumonia, bronchitis, asthma, emphysema;
a decrease in respiratory volume leads to attacks of suffocation and a complete cessation of respiratory function.

In addition to affecting the respiratory system, chronic ozone poisoning entails pathological processes in the functioning of other body systems:

the development of neurological disorders - a decrease in the level of concentration and attention, the appearance of headaches, impaired coordination of movements;
exacerbation of chronic diseases;
violation of blood clotting, the development of anemia, the occurrence of bleeding;
exacerbation of allergic reactions;
violation of oxidative processes in the body, as a result of which free radicals spread and the destruction of healthy cells occurs;
development of atherosclerosis;
deterioration of the secretory functionality of the stomach.

First aid for ozone poisoning

Acute ozone poisoning can lead to serious consequences, even death, therefore, if intoxication is suspected, the victim should be immediately provided first aid. Prior to the arrival of specialists, it is necessary to carry out the following activities:

Remove the victim from the affected area with a toxic substance or ensure the flow of fresh air into the room.
Unfasten tight clothing, give the person a half-sitting position, preventing the head from tilting back.
In case of cessation of spontaneous breathing and cardiac arrest, carry out resuscitation measures - artificial respiration from mouth to mouth and chest compressions.

If ozone comes into contact with the eyes, rinse with plenty of running water.

If a person is exposed to liquid ozone, in no case should you try to remove clothes from the victim at the place of contact with the body. Before the arrival of specialists, it is worth washing the affected area large quantity water.

In addition to providing first aid to the victim, it is necessary to immediately deliver him to medical institution or call an ambulance, since further intoxication measures can only be carried out by qualified medical personnel.

Treatment of poisoning

To eliminate ozone poisoning in a medical hospital, the following measures are taken:

perform alkaline inhalation to eliminate irritation of the upper respiratory tract;
appoint medications to stop coughing and restore respiratory functions;
in case of acute respiratory failure, the patient is connected to a ventilator;
with eye damage, vasoconstrictor and disinfecting drugs are prescribed;
in case of severe poisoning, therapy is carried out to normalize the functions of the cardiovascular system;
antioxidant therapy.

Effects

Prolonged exposure to ozone on the human body under improper working conditions or violation of the rules for using the ozonizer leads to chronic poisoning. This condition often entails the development of such consequences:

The formation of tumors. The reason for this phenomenon is the carcinogenic effect of ozone, which results in damage to the cell genome and the development of their mutation.
development of male infertility. With the systematic inhalation of ozone, a violation of spermatogenesis occurs, due to which the possibility of procreation is lost.
neurological pathologies. A person has a violation of attention, deterioration of sleep, general weakness, regular occurrence of headaches.

Prevention

To avoid ozone poisoning, experts recommend following these recommendations:

Refrain from playing sports outdoors during the hot time of the day, especially in summer. It is advisable to perform physical exercises indoors or in areas remote from large industrial enterprises and wide highways, in the morning and evening hours.
In the hot season, it is necessary to be outdoors as little as possible, especially in areas with high gas pollution.
In case of contact with ozone in industrial environments, the room must be equipped with exhaust ventilation. In addition, during the production process, it is necessary to use protective devices, as well as special sensors that display the level of gas in the room. The time of direct contact with ozone should be as short as possible.

When choosing a household ozonator, it is important to pay attention to its specifications and an appropriate certificate. Purchasing a non-certified device can lead to trivalent oxygen toxicity. Before using the device, you must familiarize yourself with the rules of its operation and precautions.

Ozone intoxication is a rather serious condition that requires immediate medical attention. Therefore, it is worth remembering that when working with this gas or using household ozonizers, it is worth adhering to safety precautions, and at the slightest suspicion of poisoning, contact a medical institution.

Introduction

Ozone (O 3) is a triatomic modification of oxygen (O 2), which under normal conditions is a gas. Ozone is a very strong oxidizing agent, so its reactions are usually very fast and complete. The main advantages of using ozone for the treatment of drinking water are found in its very nature: the result of its reaction is only oxygen and oxidation products. Harmful by-products such as organochlorine compounds are not formed.

The bluish gas ozone (O 3) has a characteristic odor. The ozone molecule is unstable. Due to its self-decomposing property, ozone is a strong oxidizing agent and the most effective tool for purification and disinfection of water and air. Strong oxidizing properties make it possible to use ozone for industrial purposes for the production of many organic substances, for bleaching paper, oils, etc. Ozone is widely used to remove manganese and iron, improve taste, eliminate color and odor, and remove environmentally hazardous organic compounds. It kills microorganisms, so ozone is used to purify water and air. Installations for water purification and air ozonation have become widespread not only in industry, but also in everyday life.

Ozone is a permanent component of the earth's atmosphere and plays an essential role in sustaining life on it. In the surface layers of the earth's atmosphere, the concentration of ozone increases sharply. General state The ozone in the atmosphere is variable, and fluctuates with the seasons. Atmospheric ozone plays a key role in sustaining life on earth. It protects the Earth from the damaging effects of a certain role of solar radiation, thereby contributing to the preservation of life on the planet.

Thus, it is necessary to find out what effects ozone can have on biological tissues.

General properties of ozone

Ozone is an allotropic modification of oxygen consisting of triatomic O 3 molecules. Its molecule is diamagnetic and has an angular shape. The bond in the molecule is delocalized, three-center

The structure of the ozone molecule can be represented in many ways. For example, a combination of two extreme (or resonant) structures. Each of these structures does not exist in reality (it is, as it were, a "drawing" of a molecule), and a real molecule is something in between two resonant structures.

Rice. 1 Structure of ozone

Both O-O connections in an ozone molecule have the same length of 1.272 angstroms. The angle between the bonds is 116.78°. central oxygen atom sp²-hybridized, has one lone pair of electrons. The molecule is polar, the dipole moment is 0.5337 D.

The nature of the chemical bonds in ozone determines its instability (after a certain time, ozone spontaneously turns into oxygen: 2O3 -> 3O2) and high oxidizing ability (ozone is capable of a number of reactions in which molecular oxygen does not enter). The oxidative effect of ozone on organic matter associated with the formation of radicals: RH + O3 RO2 + OH

These radicals initiate radically chain reactions with bioorganic molecules (lipids, proteins, nucleic acids), which leads to cell death. The use of ozone to sterilize drinking water is based on its ability to kill germs. Ozone is not indifferent to higher organisms either. Prolonged exposure to an atmosphere containing ozone (for example, in physiotherapy and quartz irradiation rooms) can cause severe damage to the nervous system. Therefore, ozone in large doses is toxic gas. Its maximum permissible concentration in the air of the working area is 0.0001 mg / liter. Ozone pollution of the air occurs during the ozonation of water, due to its low solubility.

Discovery history

Ozone was first discovered in 1785 by the Dutch physicist M. van Marum by the characteristic odor and oxidizing properties that air acquires after electric sparks are passed through it, as well as by the ability to act on mercury at ordinary temperature, as a result of which it loses its luster and begins to stick to glass . However, it was not described as a new substance; van Marum believed that a special "electric matter" was formed.

Term ozone was proposed by the German chemist X. F. Schönbein in 1840 for its odor, entered dictionaries at the end of the 19th century. Many sources give priority to the discovery of ozone in 1839 to him. In 1840 Schonbein showed the ability of ozone to displace iodine from potassium iodide:

The fact of a decrease in the volume of gas during the conversion of oxygen into ozone was experimentally proved by Andrews and Tet using a glass tube with a pressure gauge filled with pure oxygen, with platinum wires soldered into it to produce an electric discharge.

physical properties.

Ozone is a blue gas that can be seen when viewed through a significant layer, up to 1 meter thick, of ozonized oxygen. In the solid state, ozone is black with a violet tint. Liquid ozone has a deep blue color; transparent in a layer not exceeding 2 mm. thickness; pretty durable.

Properties:

§ Molecular weight - 48 a.m.u.

§ Gas density under normal conditions - 2.1445 g / dm³. Relative density of gas for oxygen 1.5; by air - 1.62

§ Liquid density at −183 °C - 1.71 g/cm³

§ Boiling point - -111.9 °C. (liquid ozone has 106 °C.)

§ Melting point - -197.2 ± 0.2 ° С (the usually given melting point -251.4 ° C is erroneous, since its determination did not take into account the great ability of ozone to supercool).

§ Solubility in water at 0 °C - 0.394 kg / m³ (0.494 l / kg), it is 10 times higher compared to oxygen.

§ In the gaseous state, ozone is diamagnetic, in the liquid state it is weakly paramagnetic.

§ The smell is sharp, specific "metallic" (according to Mendeleev - "the smell of crayfish"). At high concentrations, it smells like chlorine. The smell is noticeable even at a dilution of 1: 100,000.

Chemical properties.

Chemical properties ozone is determined by its great ability to oxidize.

The O 3 molecule is unstable and, at sufficient concentrations in air under normal conditions, it spontaneously turns into O 2 in a few tens of minutes with the release of heat. An increase in temperature and a decrease in pressure increase the rate of transition to the diatomic state. At high concentrations, the transition can be explosive.

Ozone is a powerful oxidizing agent, much more reactive than diatomic oxygen. Oxidizes almost all metals (with the exception of gold, platinum and iridium) to their higher degrees oxidation.

Properties:

1) Oxidizes many non-metals:

2) Ozone increases the degree of oxidation of oxides:

3) Ozone reacts with carbon at normal temperature to form carbon dioxide:

4) Ozone does not react with ammonium salts, but reacts with ammonia to form ammonium nitrate:

5) Ozone reacts with sulfides to form sulfates:

6) With the help of ozone, sulfuric acid can be obtained both from elemental sulfur and from sulfur dioxide:

7) All three oxygen atoms in ozone can react separately in the reaction of tin chloride with hydrochloric acid and ozone:

8) In the gas phase, ozone interacts with hydrogen sulfide to form sulfur dioxide:

15) Ozone can be used to remove manganese from water to form a precipitate that can be separated by filtration:

16) Ozone converts toxic cyanides into less dangerous cyanates:

17) Ozone can completely decompose urea

Methods for obtaining ozone

Ozone is formed in many processes accompanied by the release of atomic oxygen, for example, during the decomposition of peroxides, the oxidation of phosphorus, etc. In industry, it is obtained from air or oxygen in ozonizers by the action of an electric discharge. O3 liquefies more easily than O2 and is therefore easy to separate. Ozone for ozone therapy in medicine is obtained only from pure oxygen. When air is irradiated with hard ultraviolet radiation ozone is formed. The same process takes place in the upper layers of the atmosphere, where the ozone layer is formed and maintained under the influence of solar radiation.