Below we will dwell on obtaining oxygen from the air, but for now we will go into the room where the electric motors work and in which we deliberately turned off the ventilation.

By themselves, these engines cannot serve as a source of air pollution, since they do not consume anything from the air and do not release anything into the air. However, when breathing here, some irritation in the throat is felt. What happened to the air that was clean before the engines started?

The so-called collector motors work in this room. On the moving contacts of the motor - the lamellas - a spark often forms. In a spark at high temperature, oxygen molecules combine with each other, forming ozone (O 3).

The oxygen molecule consists of 2 atoms, which always exhibit two valences (0 = 0).

How to imagine the structure of the ozone molecule? The valency of oxygen cannot change: the oxygen atoms in ozone must also have a double bond. Therefore, the ozone molecule is usually depicted as a triangle, in the corners of which there are 3 oxygen atoms.

Ozone- gas of bluish color with a sharp specific smell. The formation of ozone from oxygen occurs with a large absorption of heat.

The word "ozone" is taken from the Greek "allos" - another and "tropos" - a turn and means the formation of simple substances from the same element.

Ozone is an allotropic modification of oxygen. This is a simple substance. Its molecule consists of 3 oxygen atoms. In technology, ozone is produced in special devices called ozonizers.

In these devices, oxygen is passed through a tube in which an electrode is placed, connected to a high voltage current source. The second electrode is a wire wound on the outside of the tube. An electric discharge is created between the electrodes, in which ozone is formed from oxygen. The oxygen leaving the ozonator contains about 15 percent ozone.

Ozone is also formed when oxygen is exposed to the rays of the radioactive element radium or a strong stream of ultraviolet rays. Quartz lamps, which are widely used in medicine, emit ultraviolet rays. That is why in a room where a quartz lamp has been working for a long time, the air becomes suffocating.

Ozone can also be obtained chemically - by the action of concentrated sulfuric acid on potassium permanganate or by the oxidation of wet phosphorus.

Ozone molecules are very unstable and easily decompose to form molecular and atomic oxygen (О 3 = O 2 + O). Since atomic oxygen oxidizes various compounds extremely easily, ozone is a strong oxidizing agent. At room temperature, it easily oxidizes mercury and silver, which are quite stable in an oxygen atmosphere.

Under the influence of ozone, organic dyes become colorless, and rubber products are destroyed, lose their elasticity and crack when lightly compressed.

Combustible substances such as ether, alcohol, lighting gas ignite when in contact with highly ozonated air. Cotton wool through which ozonized air is passed also ignites.

The strong oxidizing properties of ozone are used to disinfect air and water. Ozonated air, passed through the water, destroys pathogenic bacteria in it and somewhat improves its taste and color.

Air ozonation for the purpose of destroying harmful bacteria is not widely used, since a significant concentration of ozone is necessary for effective air purification, and in high concentration it is harmful to human health - it causes severe suffocation.

In small concentrations, ozone is even pleasant. This happens, for example, after a thunderstorm, when ozone is formed from the oxygen of the air in a huge electric spark of flashing lightning, which is gradually distributed in the atmosphere, causing a light, pleasant sensation when breathing. We experience the same thing in the forest, especially in a dense pine forest, where, under the influence of oxygen, various organic resins are oxidized with the release of ozone. Turpentine, which is part of the resin of a coniferous tree, oxidizes especially easily. That is why the air in coniferous forests always contains some amount of ozone.

At healthy person the air of a pine forest causes a pleasant sensation. And for a person with sick lungs, this air is useful and necessary for treatment. The Soviet state uses the rich pine forests in various regions of our country and creates medical sanatoriums there.

Ozone is a gaseous substance that is a modification of oxygen (consists of three of its atoms). It is always present in the atmosphere, but was first discovered in 1785 while studying the action of a spark on air by the Dutch physicist Van Marum. In 1840, the German chemist Christian Friedrich Schönbein confirmed these observations and suggested that he discovered a new element, to which he gave the name "ozone" (from the Greek ozon - smelling). In 1850, the high activity of ozone as an oxidizing agent and its ability to add to double bonds in reactions with many organic compounds were determined. Both of these properties of ozone later found wide application. practical use. However, the value of ozone is not limited to these two properties. It has been found to have a number of valuable properties as a disinfectant and deodorant.
For the first time, ozone was used in sanitation as a disinfectant. drinking water and air. Russian scientists were among the first researchers of ozonation processes. Back in 1874, the founder of the first school of (Russian) hygienists, Professor A.D. Dobroe shwin, proposed ozone as the best remedy for disinfection of drinking water and air from pathogenic microflora. Earlier, in 1886, N. K. Keldysh conducted research on the bactericidal action of ozone and recommended it as a highly effective disinfectant. The studies of ozone developed especially widely in the 20th century. And already in 1911, the first ozone water supply station in Europe was put into operation in St. Petersburg. In the same period, numerous studies were carried out on ozonation for therapeutic purposes in medicine, for sanitary purposes in Food Industry, in oxidation processes of the chemical industry, etc.
Areas and extent of ozone use in last decade are increasing at a rapid pace. Currently, the most important applications of ozone are as follows: purification and disinfection of drinking and industrial water, as well as domestic fecal and industrial effluents in order to reduce biological oxygen demand (BOD), bleaching, neutralization of harmful toxic substances (cyanides, phenols, mercaptans), elimination unpleasant odors, deodorization and air purification of various industries, ozonation in air conditioning systems, food storage, sterilization of packaging and dressing materials in the pharmaceutical industry, therapy and medical prevention of various diseases, etc.
IN last years Another property of ozone has been established - the ability to increase the biological value of animal feed and food for humans, which made it possible to use ozone in the processing, preparation and storage of feed and various products. Therefore, the development of ozonation technologies in agricultural production, and, in particular, in poultry farming, is very promising.

Physical properties of ozone

Ozone is a highly active, allotropic form of oxygen; at ordinary temperatures, it is a light-colored gas blue color with a characteristic pungent odor (the odor is organoleptically felt at an ozone concentration of 0.015 mg/m3 of air). In the liquid phase, ozone has an indigo-blue color, and in the solid phase it has a thick violet-bluish color, a layer of ozone 1 mm thick is practically opaque. Ozone is formed from oxygen, while absorbing heat, and, conversely, when decomposed, it passes into oxygen, releasing heat (similar to combustion). This process can be written in the following form:
exothermic reaction
2Oz \u003d ZO2 + 68 kcal
Endothermic reaction

The rates of these reactions depend on temperature, pressure and ozone concentration. At normal temperature and pressure, the reactions proceed slowly, but at elevated temperatures, the decomposition of ozone is accelerated.
The formation of ozone under the action of the energy of various radiations is rather complicated. The primary processes for the formation of ozone from oxygen can proceed differently depending on the amount of applied energy.
The excitation of an oxygen molecule occurs at an electron energy of 6.1 eV; the formation of molecular oxygen ions - at an electron energy of 12.2 eV; dissociation in oxygen - at an electron energy of 19.2 eV. All free electrons are captured by oxygen molecules, resulting in the formation of negative oxygen ions. After the excitation of the molecule, the reaction of ozone formation occurs.
At an electron energy of 12.2 eV, when the formation of molecular oxygen ions occurs, no ozone release is observed, and at an electron energy of 19.2 eV, when both an atom and an oxygen ion are involved, ozone is formed. Along with this, positive and negative oxygen ions are formed. The mechanism of ozone decay*, which involves homogeneous and heterogeneous systems, is complex and depends on the conditions. Ozone decomposition is accelerated in homogeneous systems by gaseous additives (nitrogen oxides, chlorine, etc.), and in heterogeneous systems by metals (mercury, silver, copper, etc.) and metal oxides (iron, copper, nickel, lead, etc.). At high concentrations of ozone, the reaction occurs with an explosion. At an ozone concentration of up to 10%, explosive decomposition does not occur. Low temperatures contribute to the conservation of ozone. At temperatures around -183°C, liquid ozone can be stored long time without noticeable decomposition. Rapid heating to the boiling point (-119°C) or rapid cooling of ozone can cause an explosion. Therefore, knowing the properties of ozone and taking precautions is very important when working with it. Table 1 shows the main physical properties of ozone.
In the gaseous state, ozone is diamagnetic, while in the liquid state, it is weakly paramagnetic. Ozone is highly soluble in essential oils, turpentine, carbon tetrachloride. Its solubility in water is more than 15 times higher than oxygen.
The ozone molecule, as already noted, consists of three oxygen atoms and has an asymmetric triangle structure, characterized by an obtuse angle at the apex (116.5 °) and equal nuclear distances (1.28 ° A) with an average binding energy (78 kcal / mol) and weakly expressed polarity (0.58).

Basic physical properties of ozone

The optical properties of ozone are characterized by its instability to radiation of various spectral composition. Radiation can not only be absorbed by ozone, destroying it, but also form ozone. The formation of ozone in the atmosphere occurs under the influence of ultraviolet radiation from the sun in the short-wavelength region of the spectrum 210-220 and 175 nm. In this case, two ozone molecules are formed per absorbed light quantum. The spectral properties of ozone, its formation and decay under the influence of solar radiation provide optimal climate parameters in the Earth's biosphere.



an arbor, characterized by an obtuse angle at the apex (116.5°) and equal nuclear distances (1.28°A) with an average binding energy (78 kcal/mol) and weak polarity (0.58).
The optical properties of ozone are characterized by its instability to radiation of various spectral composition. Radiation can not only be absorbed by ozone, destroying it, but also form ozone. The formation of ozone in the atmosphere occurs under the influence of ultraviolet radiation from the sun in the short-wavelength region of the spectrum 210-220 and 175 nm. In this case, two ozone molecules are formed per absorbed light quantum. The spectral properties of ozone, its formation and decay under the influence of solar radiation provide optimal climate parameters in the Earth's biosphere.
Ozone has a good ability to be adsorbed by silica gel and alumina gel, which makes it possible to use this phenomenon for the extraction of ozone from gas mixtures and solutions, as well as for its safe handling at high concentrations. Recently, freons have been widely used for safe operation with high concentrations of ozone. Concentrated ozone dissolved in freon can be stored for a long time.
In the synthesis of ozone, as a rule, gas mixtures (O3 + O2 or Oz + air) are formed, in which the ozone content does not exceed 2-5% by volume. Obtaining pure ozone is a technically difficult task and has not yet been solved to date. There is a method for separating oxygen from mixtures by low-temperature distillation of gas mixtures. However, it has not yet been possible to exclude the danger of an ozone explosion during rectification. In research practice, the technique of double freezing ozone with liquid nitrogen is often used, which makes it possible to obtain concentrated ozone. A safer method is to obtain concentrated ozone by adsorption - desorption, when the gas mixture flow is blown through a layer of chilled (-80°C) silica gel, and then the adsorbent is blown with an inert gas (nitrogen or helium). Using this method, you can get the ratio of ozone: oxygen \u003d 9: 1, i.e. highly concentrated ozone.
The use of concentrated ozone as an oxidizing component for industrial purposes is insignificant.

Chemical properties of ozone

The characteristic chemical properties of ozone in the first place should be considered its instability, the ability to quickly decompose, and high oxidative activity.
For ozone, the oxidation number I was established, which characterizes the number of oxygen atoms given off by ozone to the oxidized substance. As experiments have shown, it can be equal to 0.1, 3. In the first case, ozone decomposes with an increase in volume: 2Oz ---> 3O2, in the second it gives one oxygen atom to the oxidized substance: O3 -> O2 + O (at the same time, the volume does not increase), and in the third case, ozone is added to the oxidized substance: O3 -\u003e 3O (in this case, its volume decreases).
Oxidizing properties characterize the chemical reactions of ozone with inorganic substances.
Ozone oxidizes all metals, with the exception of gold and the platinum group. Sulfur compounds are oxidized by them to sulfate, nitrites - to nitrates. In reactions with iodine and bromine compounds, ozone exhibits reducing properties, and a number of methods for its quantitative determination are based on this. Nitrogen, carbon and their oxides react with ozone. In the reaction of ozone with hydrogen, hydroxyl radicals are formed: H + O3 -> HO + O2. Nitrogen oxides react with ozone quickly, forming higher oxides:
NO+Oz->NO2+O2;
NO2+O3----->NO3+O2;
NO2+O3->N2O5.
Ammonia is oxidized by ozone to ammonium nitrate.
Ozone decomposes hydrogen halides and converts lower oxides into higher ones. The halogens involved as process activators also form higher oxides.
The reduction potential of ozone - oxygen is quite high and in an acidic environment is determined by the value of 2.07 V, and in an alkaline solution - 1.24 V. The affinity of ozone with an electron is determined by a value of 2 eV, and only fluorine, its oxides and free radicals have a stronger electron affinity.
The high oxidative effect of ozone was used to transfer a number of transuranium elements to the seven-valent state, although their highest valence state is 6. The reaction of ozone with metals of variable valence (Cr, Co, etc.) finds practical application in obtaining raw materials in the production of dyes and vitamin PP .
Alkali and alkaline earth metals are oxidized under the action of ozone, and their hydroxides form ozonides (trioxides). Ozonides have been known for a long time; they were mentioned as early as 1886 by the French organic chemist Charles Adolph Wurtz. They are a red-brown crystalline substance, the lattice of molecules of which includes singly negative ozone ions (O3-), which determines their paramagnetic properties. The thermal stability limit of ozonides is -60±2° C, the content of active oxygen is 46% by weight. Like many peroxide compounds, alkali metal ozonides have found wide application in regenerative processes.
Ozonides are formed in the reactions of ozone with sodium, potassium, rubidium, cesium, which go through an intermediate unstable complex of the type M + O- H + O3 - with a further reaction with ozone, resulting in a mixture of ozonide and aqueous alkali metal oxide hydrate.
Ozone actively enters into chemical interaction with many organic compounds. Thus, the primary product of the interaction of ozone with the double bond of unsaturated compounds is a malozoid, which is unstable and decomposes into a bipolar ion and carbonyl compounds (aldehyde or ketone). The intermediate products that are formed in this reaction are recombined in a different sequence, forming an ozonide. In the presence of substances capable of reacting with a bipolar ion (alcohols, acids), various peroxide compounds are formed instead of ozonides.
Ozone actively reacts with aromatic compounds, and the reaction proceeds both with the destruction of the aromatic nucleus and without its destruction.
In reactions with saturated hydrocarbons, ozone first decomposes with the formation of atomic oxygen, which initiates chain oxidation, while the yield of oxidation products corresponds to the consumption of ozone. The interaction of ozone with saturated hydrocarbons occurs both in the gas phase and in solutions.
Phenols easily react with ozone, while the latter are destroyed to compounds with a disturbed aromatic nucleus (such as quinoin), as well as low-toxic derivatives of unsaturated aldehydes and acids.
The interaction of ozone with organic compounds is widely used in the chemical industry and related industries. Using the reaction of ozone with unsaturated compounds makes it possible to obtain artificially various fatty acids, amino acids, hormones, vitamins and polymeric materials; reactions of ozone with aromatic hydrocarbons - diphenyl acid, phthalic dialdehyde and phthalic acid, glyoxalic acid, etc.
The reactions of ozone with aromatic hydrocarbons formed the basis for the development of methods for deodorizing various environments, premises, wastewater, off-gases, and with sulfur-containing compounds - the basis for the development of methods for treating wastewater and exhaust gases of various industries, including Agriculture, from sulfur-containing harmful compounds (hydrogen sulfide, mercaptans, sulfur dioxide).

GENERAL INFORMATION.

Ozone - O3, an allotropic form of oxygen, is a powerful oxidizer of chemical and other pollutants that break down on contact. Unlike the oxygen molecule, the ozone molecule consists of three atoms and has longer bonds between the oxygen atoms. In terms of its reactivity, ozone is second only to fluorine.

Discovery history
In 1785, the Dutch physicist Van Marum, while conducting experiments with electricity, drew attention to the smell during the formation of sparks in an electric machine and to the oxidizing ability of air after passing electric sparks through it.
In 1840, the German scientist Sheinbein, engaged in the hydrolysis of water, tried to decompose it into oxygen and hydrogen using an electric arc. And then he discovered that a new one had formed, hitherto not known to science gas with a specific odor. The name "ozone" was given to the gas by Sheinbein because of the characteristic smell and comes from Greek word“ozien”, which means “to smell”.
On September 22, 1896, the inventor N. Tesla patented the first ozone generator.

Physical properties of ozone.
Ozone can exist in all three aggregate states. At normal conditions ozone is a bluish gas. The boiling point of ozone is 1120C and the melting point is 1920C.
Thanks to its chemical activity ozone has a very low maximum permissible concentration in the air (commensurate with the MPC of chemical warfare agents) of 5 10-8% or 0.1 mg/m3, which is 10 times more than the olfactory threshold for humans.

Chemical properties of ozone.
First of all, two main properties of ozone should be noted:

Ozone, unlike atomic oxygen, is a relatively stable compound. It spontaneously decomposes at high concentrations, with the higher the concentration, the faster the decomposition reaction rate. At ozone concentrations of 12-15%, ozone can decompose explosively. It should also be noted that the process of ozone decomposition accelerates with increasing temperature, and the decomposition reaction itself 2O3>3O2 + 68 kcal is exothermic and is accompanied by the release of a large amount of heat.

O3 -> O + O 2
O3 + O -> 2 O2
O2 + E- -> O2-

Ozone is one of the strongest natural oxidizers. The oxidation potential of ozone is 2.07 V (for comparison, fluorine is 2.4 V, and chlorine is 1.7 V).

Ozone oxidizes all metals with the exception of gold and the platinum group, additionally oxidizes sulfur and nitrogen oxides, and oxidizes ammonia to form ammonium nitrite.
Ozone actively reacts with aromatic compounds with the destruction of the aromatic nucleus. In particular, ozone reacts with phenol to destroy the nucleus. Ozone actively interacts with saturated hydrocarbons with the destruction of double carbon bonds.
The interaction of ozone with organic compounds is widely used in the chemical industry and related industries. The reactions of ozone with aromatic compounds formed the basis for deodorization technologies for various environments, premises and wastewater.

Biological properties of ozone.
Despite a large number of research mechanism is not well understood. It is known that at high concentrations of ozone, lesions are observed respiratory tract, lungs and mucous membranes. Prolonged exposure to ozone leads to the development of chronic diseases of the lungs and upper respiratory tract.
Exposure to small doses of ozone has a preventive and therapeutic effect and is beginning to be actively used in medicine - primarily for dermatology and cosmetology.
In addition to the great ability to destroy bacteria, ozone is highly effective in destroying spores, cysts (dense shells that form around unicellular organisms, for example, flagellates and rhizomes, during their reproduction, as well as under unfavorable conditions for them) and many other pathogenic microbes.

Technological applications of ozone
In the last 20 years, the applications of ozone have expanded significantly and new developments are underway around the world. Such a rapid development of technologies using ozone is facilitated by its environmental friendliness. Unlike other oxidizing agents, ozone decomposes during reactions into molecular and atomic oxygen and saturated oxides. All these products are generally non-polluting environment and do not lead to the formation of carcinogenic substances, as, for example, when oxidized with chlorine or fluorine.

Water:
In 1857, with the help of the "perfect tube of magnetic induction" created by Werner von Siemens, it was possible to build the first technical ozone installation. In 1901, Siemens built the first hydroelectric station with an ozone generator in Wiesband.
Historically, the use of ozone began with installations for the preparation of drinking water, when in 1898 the first pilot plant was tested in the city of Saint Maur (France). Already in 1907, the first water ozonation plant was built in the city of Bon Voyage (France) for the needs of the city of Nice. In 1911, a drinking water ozonation station was put into operation in St. Petersburg.
Currently, 95% of drinking water in Europe is treated with ozone. The US is in the process of switching from chlorination to ozonation. There are several large stations in Russia (in Moscow, Nizhny Novgorod and other cities).

Air:
The use of ozone in water purification systems has been proven in the highest degree effective, but so far no equally effective and proven safe air purification systems have been created. Ozonation is considered a non-chemical cleaning method and is therefore popular among the population. At the same time, the chronic impact of micro-ozone concentrations on the human body has not been sufficiently studied.
With a very low concentration of ozone, the air in the room feels pleasant and fresh, and unpleasant odors are felt much weaker. Contrary to popular belief about the beneficial effects of this gas, which is attributed in some prospectuses to ozone-rich forest air, in reality, ozone, even at high dilution, is a very toxic and dangerous irritant gas. Even low concentrations of ozone can irritate mucous membranes and cause disturbances in the central nervous system, leading to bronchitis and headaches.

Medical applications of ozone
In 1873, Foke observed the destruction of microorganisms under the influence of ozone, and this unique property of ozone attracted the attention of physicians.
The history of the use of ozone for medical purposes dates back to 1885, when Charlie Kenworth first published his report to the Florida Medical Association, USA. Brief information about the use of ozone in medicine was found even before this date.
In 1911, M. Eberhart used ozone in the treatment of tuberculosis, anemia, pneumonia, diabetes, and other diseases. A. Wolf (1916) during the First World War used an oxygen-ozone mixture for the wounded with complex fractures, phlegmon, abscesses, purulent wounds. N. Kleinmann (1921) used ozone for the general treatment of "body cavities". In the 30s. 20th century E.A. Fish, a dentist, begins ozone treatment in practice.
In an application for the invention of the first laboratory device, Fish proposed the term "CYTOZON", which is still used today on ozone generators used in dental practice. Joachim Hanzler (1908-1981) created the first medical ozone generator, which made it possible to accurately dose the ozone-oxygen mixture, and thus made it possible to widely use ozone therapy.
R. Auborg (1936) revealed the effect of scarring of colon ulcers under the influence of ozone and drew attention to the nature of its general effect on the body. Work on the study of the therapeutic effect of ozone during the Second World War was actively continued in Germany, the Germans successfully used ozone for the local treatment of wounds and burns. However, after the war, research was interrupted for almost two decades, due to the advent of antibiotics, the lack of reliable, compact ozone generators and ozone-resistant materials. Extensive and systematic research in the field of ozone therapy began in the mid-1970s, when ozone-resistant polymer materials and user-friendly ozone units appeared in everyday medical practice.
Research in vitro , that is, under ideal laboratory conditions, have shown that when interacting with the cells of the body, ozone oxidizes fats and forms peroxides - substances that are harmful to all known viruses, bacteria and fungi. In terms of action, ozone can be compared with antibiotics, with the difference that it does not “plant” the liver and kidneys, and has no side effects. But unfortunately, in vivo - in real conditions, everything is much more complicated.
Ozone therapy at one time was very popular - many considered ozone almost a panacea for all ailments. But a detailed study of the effects of ozone showed that, along with the sick, ozone also affects healthy cells of the skin and lungs. As a result, unforeseen and unpredictable mutations begin in living cells. Ozone therapy has not taken root in Europe, and in the US and Canada, the official medical use of ozone is not legalized, with the exception of alternative medicine.
In Russia, unfortunately, official medicine has not abandoned such a dangerous and insufficiently tested method of therapy. Currently, air ozonizers and ozonator installations are widely used. Small ozone generators are used in the presence of people.

OPERATING PRINCIPLE.
Ozone is formed from oxygen. There are several ways to produce ozone, among which the most common are: electrolytic, photochemical and electrosynthesis in gas discharge plasma. In order to avoid unwanted oxides, it is preferable to obtain ozone from pure medical oxygen using electrosynthesis. The concentration of the resulting ozone-oxygen mixture in such devices is easy to vary - either by setting a certain power of the electric discharge, or by adjusting the flow of incoming oxygen (the faster oxygen passes through the ozonator, the less ozone is formed).

Electrolytic the method of ozone synthesis is carried out in special electrolytic cells. Solutions of various acids and their salts (H2SO4, HClO4, NaClO4, KClO4) are used as electrolytes. The formation of ozone occurs due to the decomposition of water and the formation of atomic oxygen, which, by joining an oxygen molecule, forms ozone and a hydrogen molecule. This method makes it possible to obtain concentrated ozone, but it is very energy intensive, and therefore it has not found wide application.
Photochemical ozone production method is the most common method in nature. Ozone is formed by the dissociation of an oxygen molecule under the action of short-wave UV radiation. This method does not allow obtaining high concentration ozone. Devices based on this method have become widespread for laboratory purposes, in medicine and the food industry.
electrosynthesis ozone is the most widespread. This method combines the possibility of obtaining high concentrations of ozone with high productivity and relatively low energy consumption.
As a result of numerous studies on the use various kinds gas discharge for the electrosynthesis of ozone, devices using three forms of discharge have become widespread:

1. barrier discharge - the most widespread, is a large set of pulsed microdischarges in a gas gap 1-3 mm long between two electrodes separated by one or two dielectric barriers when the electrodes are powered by an alternating high voltage with a frequency of 50 Hz to several kilohertz. The capacity of one unit can range from grams to 150 kg of ozone per hour.
2. surface discharge - close in shape to a barrier discharge, which has become widespread in the last decade due to its simplicity and reliability. It is also a set of microdischarges developing along the surface of a solid dielectric when the electrodes are supplied with an alternating voltage with a frequency of 50 Hz to 15-40 kHz.
3. impulse discharge - as a rule, a streamer corona discharge that occurs in the gap between two electrodes when the electrodes are fed with a pulsed voltage with a duration from hundreds of nanoseconds to units of microseconds.

• Effective in cleaning indoor air.
• They do not produce harmful by-products.
• Facilitates conditions for allergy sufferers, asthmatics, etc.

In 1997, ozone generator companies Living Air Corporation, Alpine Industries Inc. (now “Ecoguest”), Quantum Electronics Corp. and others who violated the US FTC order were punished by the courts in an administrative manner, including a ban on the further activities of some of them in the United States. At the same time, private entrepreneurs who sold ozone generators with recommendations to use them in rooms with people received prison terms ranging from 1 to 6 years.
Currently, some of these Western companies are successfully developing active sales of their products in Russia.

Disadvantages of ozonizers:
Any sterilization system using ozone requires careful safety monitoring, testing of the ozone concentration constant with gas analyzers, and emergency management of excessive ozone concentrations.
The ozonator is not designed to work in:

• environment saturated with electrically conductive dust and water vapor,
• places containing active gases and vapors that destroy metal,
• places with relative humidity over 95%,
• in explosive and fire hazardous areas.

The use of ozonizers for indoor air sterilization:

• lengthens the sterilization process,
• increases toxicity and air oxidation,
• leads to an explosion hazard,
• the return of people to the disinfected room is possible only after the complete decomposition of ozone.

SUMMARY.
Ozonation is highly effective for sterilizing surfaces and indoor air, but there is no effect of air purification from mechanical impurities. The impossibility of using the method in the presence of people and the need to carry out disinfection in a sealed room seriously limits the scope of its professional application.

The phrase "ozone layer", which became famous in the 70s. the last century, has long been set on edge. At the same time, few people really understand what this concept means and why the destruction of the ozone layer is dangerous. An even bigger mystery for many is the structure of the ozone molecule, and yet it is directly related to the problems of the ozone layer. Let's learn more about ozone, its structure and industrial applications.

What is ozone

Ozone, or, as it is also called, active oxygen, is an azure gas with a pungent metallic odor.

This substance can exist in all three states of aggregation: gaseous, solid and liquid.

At the same time, ozone occurs in nature only in the form of a gas, forming the so-called ozone layer. It is because of its azure color that the sky appears blue.

What does an ozone molecule look like?

Ozone got its nickname "active oxygen" because of its resemblance to oxygen. So the main acting chemical element in these substances is oxygen (O). However, if an oxygen molecule contains 2 of its atoms, then the molecule - O 3) consists of 3 atoms of this element.

Due to this structure, the properties of ozone are similar to those of oxygen, but more pronounced. In particular, like O 2 , O 3 is the strongest oxidizing agent.

The most important difference between these "related" substances, which is vital for everyone to remember, is the following: ozone cannot be breathed, it is toxic and, if inhaled, can damage the lungs or even kill a person. At the same time, O 3 is perfect for cleaning the air from toxic impurities. By the way, it is because of this that after rain it is so easy to breathe: ozone oxidizes harmful substances contained in the air, and it is purified.

The model of the ozone molecule (consisting of 3 oxygen atoms) looks a bit like an image of an angle, and its size is 117°. This molecule has no unpaired electrons and is therefore diamagnetic. In addition, it has polarity, although it consists of atoms of one element.

Two atoms of a given molecule are firmly bonded to each other. But the connection with the third is less reliable. For this reason, the ozone molecule (photo of the model can be seen below) is very fragile and soon after formation it breaks down. As a rule, in any reaction of the decomposition of O 3, oxygen is released.

Due to the instability of ozone, it cannot be harvested, stored, or transported like other substances. For this reason, its production is more expensive than other substances.

At the same time, the high activity of O 3 molecules allows this substance to be the strongest oxidizing agent, more powerful than oxygen, and safer than chlorine.

If the ozone molecule is destroyed and O 2 is released, this reaction is always accompanied by the release of energy. At the same time, in order for the reverse process to occur (the formation of O 3 from O 2), it is necessary to spend it no less.

In the gaseous state, the ozone molecule decomposes at a temperature of 70 ° C. If it is raised to 100 degrees or more, the reaction will accelerate significantly. The presence of impurities also accelerates the decay period of ozone molecules.

O3 properties

In whichever of the three states ozone is, it retains Blue colour. The harder the substance, the richer and darker this shade.

Each ozone molecule weighs 48 g/mol. It is heavier than air, which helps to separate these substances from each other.

O 3 is able to oxidize almost all metals and non-metals (except gold, iridium and platinum).

Also, this substance can participate in the combustion reaction, but this requires more heat than for O 2 .

Ozone is able to dissolve in H 2 O and freons. In the liquid state, it can be mixed with liquid oxygen, nitrogen, methane, argon, carbon tetrachloride and carbon dioxide.

How is the ozone molecule formed?

O 3 molecules are formed by attaching free oxygen atoms to oxygen molecules. They, in turn, appear due to the splitting of other O 2 molecules due to the effect on them of electrical discharges, ultraviolet rays, fast electrons and other high energy particles. For this reason, the specific smell of ozone can be felt near sparking electrical appliances or lamps emitting ultraviolet light.

On an industrial scale, O 3 is isolated using electric or ozonizers. In these devices electricity high voltage is passed through a gas stream in which O 2 is located, whose atoms serve as " building material» for ozone.

Sometimes pure oxygen or ordinary air is run into these apparatuses. The quality of the resulting ozone depends on the purity of the initial product. So, medical O 3, intended for the treatment of wounds, is extracted only from chemically pure O 2.

History of the discovery of ozone

Having figured out what the ozone molecule looks like and how it is formed, it is worth getting acquainted with the history of this substance.

It was first synthesized by the Dutch researcher Martin van Marum in the second half of the 18th century. The scientist noticed that after passing electric sparks through a container with air, the gas in it changed its properties. At the same time, Van Marum did not understand that he had isolated the molecules of a new substance.

But his German colleague named Sheinbein, trying to decompose H 2 O into H and O 2 with the help of electricity, drew attention to the release of a new gas with a pungent odor. After a lot of research, the scientist described the substance he discovered and gave it the name "ozone" in honor of the Greek word for "smell".

The ability to kill fungi and bacteria, as well as reduce the toxicity of harmful compounds, which the open substance possessed, interested many scientists. 17 years after the official discovery of O 3, Werner von Siemens designed the first apparatus that made it possible to synthesize ozone in any quantity. And 39 years later, the brilliant Nikola Tesla invented and patented the world's first ozone generator.

It was this device that was first used in France in 2 years at drinking water treatment plants. Since the beginning of the XX century. Europe is beginning to switch to ozonation of drinking water for its purification.

The Russian Empire first used this technique in 1911, and after 5 years, almost 4 dozen installations for drinking water purification using ozone were equipped in the country.

Today, water ozonation is gradually replacing chlorination. Thus, 95% of all drinking water in Europe is treated with O 3 . This technique is also very popular in the USA. In the CIS, it is still under study because, although the procedure is safer and more convenient, it is more expensive than chlorination.

Applications of ozone

In addition to water purification, O 3 has a number of other applications.

• Ozone is used as a bleach in the manufacture of paper and textiles.
• Active oxygen is used to disinfect wines, as well as to accelerate the aging process of cognacs.
• With the help of O 3, various vegetable oils are refined.
• Very often, this substance is used to process perishable products, such as meat, eggs, fruits and vegetables. This procedure does not leave chemical traces, as with the use of chlorine or formaldehyde, and products can be stored much longer.
• Ozone sterilizes medical equipment and clothing.
• Also, purified O 3 is used for various medical and cosmetic procedures. In particular, with its help in dentistry, they disinfect the oral cavity and gums, and also treat various diseases (stomatitis, herpes, oral candidiasis). In European countries, O 3 is very popular for wound disinfection.
• In recent years, portable home appliances for filtering air and water using ozone have gained immense popularity.

Ozone layer - what is it?

At a distance of 15-35 km above the Earth's surface is the ozone layer, or, as it is also called, the ozonosphere. In this place, concentrated O 3 serves as a kind of filter for harmful solar radiation.

Where does such an amount of a substance come from if its molecules are unstable? It is not difficult to answer this question if we recall the model of the ozone molecule and the method of its formation. So, oxygen, consisting of 2 oxygen molecules, getting into the stratosphere, is heated there by the sun's rays. This energy is enough to split O 2 into atoms, from which O 3 is formed. At the same time, the ozone layer not only uses part of the solar energy, but also filters it, absorbs dangerous ultraviolet radiation.

It was said above that ozone is dissolved by freons. These gaseous substances (used in the manufacture of deodorants, fire extinguishers and refrigerators), once released into the atmosphere, affect ozone and contribute to its decomposition. As a result, holes appear in the ozonosphere through which unfiltered solar rays enter the planet, which have a destructive effect on living organisms.

Having considered the features and structure of ozone molecules, we can conclude that this substance, although dangerous, is very useful for mankind if it is used correctly.

What is the benefit of ozone?

Ozone, being a strong oxidizing agent, is widely used in various areas of our life. It is used in medicine, in industry, in everyday life.

What is ozone gas?

During a thunderstorm, when electric discharges of lightning “pierce” the atmosphere, we feel the resulting ozone as fresh air. Ozone really cleans our air! Being a strong oxidizing agent, it decomposes many toxic impurities in the atmosphere into simple safe compounds, thereby disinfecting the air. That is why after a thunderstorm we feel a pleasant freshness, we breathe easily, and we see everything around us more clearly, especially the blue of the sky.

Ozone is a blue gas with a characteristic odor and a very strong oxidizing agent. Molecular formula of ozone is O3. It is heavier than oxygen and our habitual air.

The ozone generation scheme is as follows: under the influence of an electric discharge, a part of the oxygen molecules O2 decomposes into atoms, then atomic oxygen combines with molecular oxygen and ozone O3 is formed. In nature, ozone is formed in the stratosphere under the influence of ultraviolet radiation from the sun, as well as during electrical discharges in the atmosphere.

Household ozonation devices give a safe concentration of ozone for humans. With the help you will always breathe fresh and clean air

Where is ozone used today?

The most common application- for water purification. Ozone effectively destroys bacteria and viruses, eliminates organic water pollution, eliminates odors, can
be used as a bleaching agent.

A special role is given to ozone in the food industry. Being a highly disinfectant and chemically safe agent, it is used to prevent the biological growth of unwanted organisms in foodstuffs.
and on technological food equipment. Ozone has the ability to kill microorganisms without creating new harmful chemicals.

All chemicals that are in the air, reacting with ozone, decompose into harmless compounds: carbon dioxide, water and oxygen.

What is it needed for ?

1. Purification of air in residential premises, in bathrooms and toilet rooms.
2. Elimination of unpleasant odors in the refrigerator, wardrobes, pantries, etc.
3. Purification of drinking water, ozonation of bathtubs, aquariums.
4. Food processing (vegetables, fruits, eggs, meat, fish).
5. Disinfection and elimination of dirt and unpleasant odors when washing clothes.
6. Cosmetological procedure, care for the oral cavity, skin of the face, hands and feet.
7. Elimination of the smell of tobacco smoke, paint, varnish

Ozone in medicine

Ozone in therapeutic doses acts as an immunomodulating, anti-inflammatory, bactericidal, antiviral, fungicidal, cystostatic, anti-stress and analgesic agent.

Ozone therapy is successfully used in almost all areas of medicine: in emergency and purulent surgery, general and infectious therapy, gynecology, urology,
dermatology, hepatology, gastroenterology, dentistry, cosmetology, etc.

What are the effects of ozone therapy?

1. Activation of detoxification processes. There is a suppression of the activity of external and internal toxins.
2. Activation of metabolic processes (metabolic processes).
3. Normalization of the process of lipid peroxidation (fat metabolic processes).

The use of ozone enhances the consumption of glucose by tissues and organs, increases the saturation of blood plasma with oxygen, reduces the degree of oxygen starvation,
improves microcirculation.

Ozone has a positive effect on the metabolism of the liver and kidneys, supports the work of the heart muscle, reduces the respiratory rate and increases the respiratory volume.

The positive effect of ozone on people with diseases of the cardiovascular system (the level of cholesterol in the blood decreases, the risk of thrombosis decreases, the process of "breathing" of the cell is activated).

Ozone therapy in treatment herpes allows you to significantly reduce the course and dose of antiviral drugs.

At decreased immunity ozone therapy stimulates the body's resistance to diseases such as influenza, tonsillitis, SARS, acute respiratory infections so popular in autumn and winter.

When sick" chronic fatigue syndrome caused by cytomegalovirus And herpes virus, ozone therapy helps to get rid of headaches, fatigue, increases efficiency and overall vitality. Ozone therapy gives the same effect in the treatment of ordinary fatigue, chronic lack of sleep, overwork, almost instantly relieving syndromes.

Ozone therapy (autohemotherapy with ozone) is widely used in cosmetology For wrinkle correction general "rejuvenation" of the skin, problem skin treatment and acne, including teenage ones, acne rash.

With the help of ozone, extra pounds go great! In order to reduce weight, cure cellulite and remove volume on the abdomen, thighs, buttocks, systemic and local use of ozone is recommended.

Are there any contraindications to the use of ozone therapy?

Yes, there are contraindications. Therefore, be very careful when prescribing ozone therapy, consult your doctor, discuss the ways and methods of exposure, possible reactions of the body.

Ozone therapy should not be used in acute myocardial infarction, internal bleeding, hyperthyroidism, a tendency to convulsions, thrombocytopenia.