What is smog and its types. Smog is an environmental problem

In the modern world there are more and more eco-products, clean water and cleaned streets, but one problem - dirty air - remains unresolved. Smog continues to fill the streets of industrial cities.

Air samples taken in the centers of large cities, quite far from plants and factories, show the presence of thousands of microscopic dust particles and ash particles per cubic centimeter of air. And bacteria, including pathogenic ones, ride “on horseback” on these specks of dust.

Each city is looking for its own ways to solve the problem of smog, depending on its origin. Typically, municipal equipment is used for this purpose, which waters, sweeps and vacuums the streets, and enterprises install filters that prevent the release of harmful gases and dust. In large settlements, the entry of personal vehicles into the center is often limited, pedestrian streets are installed, and more trees are planted.

The term “smog” appeared at the beginning of the twentieth century and is a merger of two English words - “smoke” (smoke) and “fog” (fog).

The air of a big city contains thousands of tons of dust - suspended particles of stone and earth, ash, construction dust, pollen, organic matter, human waste, tiny steel shavings - just a few examples of what enters the lungs of city residents with every breath. Add to this emissions from factories and car exhaust gases containing carbon monoxide.

One of the most harmful substances from this “cocktail” is soot. When inhaled, soot particles settle in the respiratory tract and sinuses, and the smallest ones reach the lungs. Soot particles damage the lungs, and in addition, many more microbes enter the respiratory system with them. The settling soot spoils clothes, furniture, house facades - almost any surface, and harms plants.

The cities most susceptible to smog - those located in lowlands, with a lot of traffic, narrow streets, surrounded by factories - have such dirty air that 300 tons of soot, ash and industrial dust fall per square kilometer of area. In smoky factory areas, the smog can be so thick that if the dust particles inhaled by each resident in one hour were placed side by side, they would form a chain 15 kilometers long!

Sometimes smog can be reduced using fairly simple and inexpensive methods. Even changing the grade of coal for thermal power plants and selecting the optimal operating mode can reduce smoke emissions several times.

Oddly enough, street cleaning can sometimes only pollute the air more - when sweeping equipment not only removes dust and dirt from sidewalks and roadways, but rather lifts it into the air.

It is interesting that with a change in altitude, the amount of dust in the atmosphere changes greatly - if at the sidewalk in one cubic meter of air there are 5 million polluting particles harmful to health, then already at the level of the second floor - half as much.

And this is not just dust - microbiologists have shown that every gram of dust collected in city air contains from 100 thousand to 2 million microbes and their spores, and most of all in samples taken in public buildings, subways and churches.

Separately, it is necessary to talk about how the air in the metro is polluted. In addition to what passengers exhale, particles of their clothing and dirt that they bring to the station, technical fluids, metal shavings are floating in the subway air, removed from mechanisms, wheels and rails when they wear out. Over the course of a year, people using the subway literally inhale several tons of steel.

Another reason for the formation of smog is no less problematic - car exhaust gases, which are increasingly found on city streets. At busy intersections, traffic jams on narrow streets and in tunnels, the concentration of carbon monoxide can be several times higher than permissible, and if not for catalytic converters, with the modern saturation of transport, drivers and passers-by would faint in stacks.

The most common and effective methods for purifying air from dust are filtration, trapping solid impurities in cyclone-type devices and electrostatic deposition. Ultraviolet irradiation (for example, bactericidal lamps) is used to disinfect air.

You can see smog almost everywhere, this is because it appears in all cities. He is called a silent killer and is difficult to defend against even in an apartment. After all, the air we breathe in our home comes from outside. And how to deal with smog at home? Whether we like it or not, smog gets into apartments; we simply cannot avoid it, but we can overcome its consequences and protect ourselves from health complications. But what is smog and where does it come from?

What is it and where does smog come from?

Smog is an unnatural atmospheric phenomenon created by human activity and unfavorable natural factors, consisting of joint air pollution, which manifests itself in significant turbidity of the air in calm weather. The lack of wind in the city makes the smog stand still. Chemical components of smog, dust and moisture are often important factors in the formation of allergies and can cause asthma attacks, lead to exacerbation of chronic bronchitis, respiratory distress syndrome, and, as a rule, to a higher incidence of cancer. Several ways to protect yourself from smog at home.

Plants will become allies

One of the easiest and at the same time natural ways is to invest in indoor potted plants. Some of them are simply designed to filter air and tolerate apartment living conditions well.

Humidifiers

In the apartment, special equipment that emits healthy water vapor will effectively clean and humidify the air. Their maintenance is simple - just pour water into the container and select the appropriate mode. Water vapor causes dust and dirt to settle on the floor or furniture, so we don't inhale it. Humidifiers are also increasingly recommended for asthmatics and allergy sufferers.

Mechanical and automatic filters

More and more often on city streets you can see people wearing white masks with filters, as in photographs from distant Japan. These masks protect people from air pollution and can be used at home. We can find more and more masks with modern designs on the market.

Another, more advanced, convenient and effective solution is to purchase a household air purifier. Which air purifier should you choose? Let's be guided by proven brands, because the price here is health. Such devices remove gases and all allergens and pollutants from the air. Many branded devices also have an ionizer function and can kill germs using UV rays while cooling or heating the room. We can use them for many purposes, with health always at the forefront.

Causes of smog formation and consequences

How to fight smog

Fighting smog is a very difficult task. As we know, smog is polluted air. And air will pass everywhere, it is everywhere and it is vital for a person. Air easily penetrates into the smallest cracks and fills the room with acrid smoke.

Due to the difficult situation that has developed in Central Russia in recent summer months, it is worth paying attention to protecting premises from smog.

If you are the happy owner of air conditioners, then feel free to close all windows, doors and turn on the air conditioner to the temperature you need. Just remember that air conditioners can cause colds. You should also be careful when leaving an air-conditioned room, as stepping out into hot, dirty air can take your breath away.

Those who do not have air conditioning should not be discouraged either. Hang gauze on the windows - thick, but so that air flows well. Constantly moisten the gauze with water so that dust and dirt settle on it, and clean air enters your room. Do wet cleaning more often than usual. Fill the bathtub and any other containers in the house with water to increase the humidity. Drink more water.

My wish for everyone is to appear on the street as little as possible. Do not stay for a long time in confined spaces (elevators, minibuses, trams - there is usually no ventilation there). If possible, leave the city and visit friends or relatives in less smoky areas. Just be careful - do not cross the smoke screen on the roads, reduce the time you drive along a smoke-filled road, if your health worsens, immediately leave your place of stay, drink water, pour it on your face, call an ambulance or ask others to help.

Good health to you, and God bless you!

Smog, translated from English, means Smoke Fog. It is also often called photochemical fog. These two names describe this phenomenon quite clearly.
Air so polluted with harmful substances that it is visible as ordinary fog.

Smog forms only under certain weather conditions, the main one of which is calmness, and the influence of the Sun is also very important. It is formed from nitrogen oxides, nitrate peroxide and various chemicals such as solvents, gasoline vapors, pesticides and others.
You can imagine the impact this mixture has on human health. But some cities are completely covered in photochemical fog! Moscow, London, Beijing, Athens...

Many capitals are the most dangerous places in the world. And people live here, constantly breathing a deadly mixture of substances. And many of them have serious health problems. The respiratory organs and circulatory system are especially susceptible to harmful effects. So strong an impact that people not only go to hospitals, but also die.

Conclusion

Photochemical fog is one of the main problems of mankind. But the saddest thing is that all measures to combat this phenomenon are aimed not at preventing its formation, but at eliminating the consequences. Almost no one wants to give up the benefits of humanity, which kill not only nature, but also themselves. Convenience is much more important than your own health and the health of others.

Humanity's real problem is not smog, nor global warming, nor the formation of ozone holes.

Smog: facts, consequences, precautions

The problem is in the people themselves, in their unconsciousness. Well, who is ready to give up a car to preserve their health? Maybe from cigarettes? There are no people willing, everyone thinks that their car alone won’t make a difference, just like an extra cigarette smoked.

Lecture 10. Chemical transformations in the troposphere. The occurrence of smog.

Smog (from English Smoky fog, literally “Smoke fog”) is an aerosol consisting of smoke, fog and dust, one of the types of air pollution in large cities and industrial centers. Smog is a combination of gaseous and solid impurities with fog or aerosol haze.

Originally, smog meant smoke produced by burning large amounts of coal (a mixture of smoke and sulfur dioxide SO2). In the 1950s a new type of smog was first described - photochemical, which is the result of mixing the following pollutants in the air:

— nitrogen oxides, for example, nitrogen dioxide (products of combustion of fossil fuels);

— tropospheric (ground-level) ozone;

— volatile organic substances (vapors from gasoline, paints, solvents, pesticides and other chemicals);

- nitrate peroxides.

All of the listed chemicals usually have high chemical activity and are easily oxidized, so photochemical smog is considered one of the main problems of modern civilization.

Radiation fog is fog that appears as a result of radiation cooling of the earth's surface and the mass of moist surface air to the dew point. Typically, radiation fog occurs at night in anticyclone conditions with cloudless weather and a light breeze. Radiation fog often occurs under conditions of temperature inversion, which prevents the rise of the air mass.

An extreme form of radiation fog, smog, can occur in industrial areas.

London-type damp smog is a combination of fog mixed with smoke and gas waste from production. London-type smog is caused by the combustion of coal and fuel oil. When atmospheric humidity is high, a thick fog mixed with soot particles and SO2 is formed.

Smog, its causes and consequences. Ways to reduce air pollution

This “smog” got its name after the tragedy in the winter of 1952, when 3,200 people died in London as a result of its formation.

Alaskan-type ice smog is smog formed at low temperatures from steam from heating systems and household gas emissions.

Dry smog of the Los Angeles type is smog resulting from photochemical reactions that occur in gas emissions under the influence of solar radiation; a persistent bluish haze of corrosive gases without fog. Photochemical smog is smog, the main cause of which is considered to be automobile exhaust. Car exhaust gases and polluting emissions from enterprises in conditions of temperature inversion enter into a chemical reaction with solar radiation, forming ozone. In some cases, photochemical smog may contain nitrogen compounds, which increase the likelihood of cancer.

Photochemical “smog” was first noted in 1944 in Los Angeles, when life in one of the largest US cities was paralyzed as a result of a large congestion of cars. Photochemical smog occurs under the influence of sunlight in the absence of wind and low air humidity. Severe irritation of the mucous membranes of the respiratory tract and eyes is observed. The persistence of the smog situation for a long time leads to an increase in morbidity and mortality among the population. It also has a harmful effect on vegetation, causing wilting and death of leaves. In addition, photochemical “smog” increases the corrosion of metals and the destruction of building structures, rubber and other materials.

The oxidative character of photochemical “smog” is given by ozone and peroxylacetyl nitrates. Measurements carried out in the 1950s in Los Angeles show that an increase in ozone concentration is associated with a characteristic change in the relative content of NO2 and NO.

Decreased visibility during smog (the appearance of a bluish haze) is associated with the formation of aerosol particles. The emergence of aerosols and their subsequent removal in the processes of adhesion, dry and wet (with precipitation) deposition is one of the main ways of self-purification of the atmosphere.

Atmospheric organic aerosols can be formed by a homogeneous or heterogeneous mechanism. The first of them includes gaseous oxidation of organic compounds with the formation of solid or liquid particles, the second involves sorption, catalytic oxidation, polymerization on the surface of existing solid and liquid aerosols.

Aerosol particles either enter the atmosphere in finished form (as a result of volcanic activity, fires, sea salt, dust, etc.), or are formed from gas emissions directly in the atmosphere as a result of chemical processes.

Of the numerous organic compounds entering the atmosphere, terpene hydrocarbons exhibit the greatest tendency to form aerosols. Thus, the bluish haze observed over coniferous forests in the summer is an aerosol resulting from the photochemical oxidation of terpenes.

The formation of aerosol particles in urban air is often associated with SO2, which, when oxidized, produces H2SO4, which turns into ammonium sulfate in the presence of ammonia in the atmosphere.

The amount of particulate matter in the air varies greatly depending on the area. In the lower troposphere, at altitudes less than 2 km, in rural areas the particle concentration is about 104 cm-3, and above cities it exceeds 105 cm-3. In background areas, in the absence of anthropogenic activity, the air contains only 200–600 cm-3 of aerosol particles.

123Next ⇒

The reasons for the formation of smog can be the following:

car exhaust gases;

activities of power plants and factories;

natural and peat fires;

coal burning;

harmful fumes from many consumer products, including chemical solvents, paint or even hairspray.

When sunlight and heat react with harmful gases and particles in the atmosphere, then harmful fog is created.

The main occurrences of smog are often associated with heavy vehicle traffic, high temperatures, sunlight and calm weather. Thus, low wind speed allows the smog to stagnate in a certain area. Stagnation can also be facilitated by a temperature inversion, in which warm air at the surface of the earth and all the pollutants in it are blocked by a “lid” of cold air.

In addition to other harmful substances and gases, smog contains carbon monoxide, familiar to us as carbon monoxide. It is not noticeable to us because it has neither odor nor color, but its suffocating effects can significantly affect health and even lead to death.

Types of smog

At least four types of smog are known: sulfur, photochemical, volcanic and ice.

London type damp smog

This type is also called sulfur. It is the result of high concentrations of sulfur oxides in the air and is caused by the use of sulfur-containing fuels, in particular coal. The danger of this type is aggravated by the high concentration of suspended particles in the air.

Los Angeles-type photochemical (dry) smog

Photochemical, or white, smog- This is the most common type today. It is formed by the interaction of several substances:

Nitrogen oxides. They are formed during the combustion of fuel due to the activities of thermal power plants, combined heat and power plants, metallurgy and other areas of industrial production. Exhaust gases also influence the appearance of nitrogen oxides. The minimal effects of these compounds are eye and nasopharyngeal irritation and difficulty breathing.

Ozone. Ozone is one of the main factors influencing the formation of photochemical smog, and although in the upper layers of the atmosphere it is a beneficial chemical that protects us from solar radiation, in the lower layers it is a pollutant that can be harmful to human health.

Suspended particles PM2.5. These are tiny particles of dust, soot, ash and other contaminants that we cannot see with the naked eye. PM2.5 is very dangerous to human health: it shortens life expectancy and is associated with lung cancer and diseases of the respiratory and cardiovascular systems. Fortunately, there are now HEPA filters, blocking the entry of these particles into the room.

Volatile organic compounds. These are vapors from paints, solvents, gasoline and other toxic substances.

Photochemical smog is an aerosol produced when sunlight reacts with nitrogen oxides, hydrocarbons and volatile organic compounds that can be found in exhaust gases and emissions from factories and power plants. As a result, the smog has a light brown color.

Volcanic smog

Volcanic smog is a species that is formed in the atmosphere as a result of a volcanic eruption. Harmful gases and particles are released from the vent and react with sunlight and oxygen. Some chemicals in volcanic smog can harm people, animals and plants. People may experience breathing problems, mucosal irritation and sore throat. This type is typical for countries where there are active volcanoes, for example, the Hawaiian Islands.

Today everyone knows what smog is - it is nothing more than a mixture of smoke, dust and fog. Any smog, regardless of how it appeared, has a bad effect on the human body. More dangerous, however, is the smog that we cannot see than the visible one. Since invisible smog consists of vapors, aerosols and corrosive gases. The most dangerous thing is when it begins to be irradiated by solar radiation and then photochemical reactions begin. As a result, new chemical mixtures arise, often even more aggressive and toxic than the previous ones, such as nitrites, nitrogen oxides, phenols.

There are several types of smog:

wet smog is a mixture of fog, smoke and gas waste from industry, which, in high concentrations, can kill several thousand people.
radiation fog - occurs as a result of radiation cooling of the earth, while air humidity must reach the dew point. Appears in anticyclone conditions at night or during a temperature inversion.
ice smog is a mixture of household gas emissions and from heating systems.
dry smog (London smog) – appears due to photochemical processes that occur in gas emissions under the influence of solar radiation; appearance is a bluish haze without fog. It often consists of a mixture of sulfur dioxide and aerosols of sulfurous acid. Most often it occurs due to a large amount of burned fuel.
Another smog (Los Angeles smog) is photochemical smog, caused by car exhaust. This is a dry fog in which exhaust, irradiated with ultraviolet light, forms new substances such as ozone and photooxidants.

The characteristic color of such smog is a yellow-green haze. So in Los Angeles, where cars release about a thousand tons of gas into the air per day and solar activity in these places is quite high. And it turns out that the city itself produces this phenomenon, which has a detrimental effect on the health of the population. Such smog can cause vomiting, lethargy and a general deterioration in a person’s well-being.

As a result of smog that pollutes the atmosphere, the following consequences may occur:

The greenhouse effect is increasing. As humanity burns more and more fuel, the concentration of substances such as methane, freons, and nitrogen oxide becomes enormous in the atmosphere. The greenhouse effect itself is a threat to increase global air temperature by significant amounts, which will lead to global warming.
The ozone layer is being depleted. Ozone layer depletion is a global environmental problem. As the thickness of this layer decreases, the ability to protect the atmosphere from strong ultraviolet radiation is significantly reduced, and as a result, the destruction of most organic molecules.
Acid precipitation. Acid rain is precipitation saturated with sulfur oxides, nitrogen oxides, hydrogen chloride, etc. Such rain leads to the destruction of forests, destruction of crops and acidification of water bodies, degradation of many organisms living in water.

All scientists in the world claim that several thousand people die every year due to exposure to polluted air.

Doctors do not advise certain categories of people to stay in places where smog often occurs. These are: asthmatics, allergy sufferers, elderly people, people suffering from heart disease, infants. They advise everyone else during the heat to go outside wearing moistened masks and always have sedatives and relaxing medications with you. After all, smog can worsen a person’s physical condition to the point of possible death.

INTRODUCTION

TYPES OF SMOG

CONSEQUENCES OF SMOG

METHODS OF COMBATING SMOG

CONCLUSION

BIBLIOGRAPHY

INTRODUCTION

The Great Smog enveloped London on December 5, 1952 and only dissipated by December 9 of the same year. The incident was a real disaster, resulting in the death of 12,000 people, which is considered to be the starting point of the modern environmental movement.

In early December 1952, a cold fog descended on London. Because of the cold, the townspeople began to use coal for heating in larger quantities than usual. Around the same time, the process of replacing urban electric transport (trams) with buses with a diesel engine was completed. Locked in by a heavier layer of cold air, combustion products in the air reached extreme concentrations in a matter of days. The fog was so thick that it prevented the movement of cars. Concerts were canceled and film screenings were stopped because the smog easily penetrated indoors. Spectators sometimes simply did not see the stage or screen due to the thick curtain.

At first, the reaction of the townspeople was calm, since fogs are not uncommon in London. In the following weeks, however, statistics collected by the city's medical services revealed the deadly nature of the disaster - the number of deaths among infants, the elderly and those suffering from respiratory diseases reached four thousand. About eight thousand more people died in the following weeks and months.

The shock of this harsh lesson caused people to change their attitude towards air pollution. The disaster made it abundantly clear to people around the world that this problem poses an immediate threat to human life. New environmental standards were adopted to limit the use of dirty fuels in industry and to ban soot-containing exhaust gases. Among the measures taken were the introduction of the Clean Air Act (versions of 1956 and 1968) and the similar City of London Act (1954).

WHAT IS SMOG AND THE REASONS FOR ITS APPEARANCE

The term "smog" was first coined by Dr. Henry Antoine de Vaux in 1905<#"703523.files/image001.gif">

The distribution of air pollution largely depends on weather and climate phenomena. Winds increase the rate of dispersion and mixing, and air currents directed from the ground carry pollutants into the upper atmosphere. However, conditions may arise in which the atmospheric layers become very stable. This, in particular, happens during anticyclones (areas with high atmospheric pressure), during calm weather in general, and during cooling of the lowest layer of air, when in the upper layers at a certain altitude the air is warmer than in the lower ones (that is, a temperature inversion is observed). Then the pollution, instead of moving to the upper layers of the atmosphere, remains near the surface of the earth. This causes colder air to sit below warmer air and cannot rise up and dissipate into the atmosphere. Under the “roof” of warm air, pollutants accumulate in such large quantities that they become hazardous to health.

Cities located in depressions are characterized by an increased frequency of temperature inversions, and, therefore, with high levels of industrial air pollution, they are prone to the formation of smog.

TYPES OF SMOG

There are three types of smog:

ice smog (Alaskan type);

humid smog (London type);

dry or photochemical smog (Los Angeles type).

Ice smog (Alaskan type) - typical for high latitudes in winter at temperatures of -30-35°C and complete calm. The air vapor in the atmosphere freezes and is absorbed onto these crystals. soot<#"703523.files/image002.gif">

NO released into the air also undergoes the same transformation.

In sunlight, NO2 undergoes photodissociation:

The resulting atomic oxygen is very active and can enter into various reactions, in particular, form ozone O3 with molecular oxygen

Where M are air molecules that absorb the released energy

The presence of ozone is the most characteristic feature of photochemical smog. It is not formed during fuel combustion, but is a secondary pollutant.

During the daytime, ozone slowly reacts with NO2, forming the radical NO3, which in turn enters into further reactions with NO and NO2. One of the end products of these reactions is N2O5. If there is water vapor in the atmosphere, then N2O5 can react with water vapor and the product of this reaction is nitric acid - HNO3.

Considering all these transformations, we did not take into account the influence of hydrocarbons, but it is their presence in the troposphere that causes a deterioration in visibility and, as a result of their partial destruction, many harmful substances are formed, including: PAN (peroxyacetyl nitrate), aldehydes, carbon monoxide (carbon monoxide), carbon dioxide gas, carboxylic acids, ketones, olefin oxides, paraffins, etc.

From the graph of the daily cycle of pollutants presented in Fig. 3, it is clear that the maximum concentration of aldehydes and ozone occurs immediately after the maximum concentration of hydrocarbons and NO2 (after 4 - 5 hours). From this we can conclude that an increase in emissions of unburned fuel into the atmosphere leads to a deterioration of the environmental situation and thereby causes additional accumulation of tropospheric ozone.

CONSEQUENCES OF SMOG

Photochemical smog affects people, plants, buildings, and various materials. Domestic animals, mainly dogs and birds, are dying.

High concentrations of oxidants - ozone, PAN, nitrogen oxides contained in photochemical smog, give it extremely unpleasant properties. People exposed to smog experience severe irritation of the mucous membranes of the eyes and respiratory tract due to the presence of substances like PAN in it. They cause lacrimation at concentrations of 0.1 ppm. If the content of such oxidants exceeds 0.25 ppm, asthma attacks, cough, chest discomfort, and headache are observed. Ozone concentrations achieved in photochemical smog are also very harmful to health. Thus, already 0.1 ppm of ozone in the air causes dry throat, irritation of the respiratory tract, and decreased resistance to bacteria. Ozone concentrations of 0.3 ppm cause breathing problems, chest spasms, and dizziness. Prolonged contact with such air leads to an increase in morbidity and mortality of people. Children and the elderly are especially vulnerable to smog.

Photochemical smog also negatively affects vegetation. Photochemical smog has a particularly bad effect on beans, beets, cereals, grapes, and ornamental plants. A sign that the plant has been exposed to the harmful effects of photochemical fog is swelling of the leaves, which then progresses to the appearance of spots and white coating on the upper leaves, and on the lower leaves leads to the appearance of a bronze or silver tint. Then the plant begins to quickly wither.

Among other things, photochemical fog leads to accelerated corrosion of materials and building elements, cracking of paints, rubber and synthetic products, and even damage to clothing.

COMPARISON OF SMOK IN LOS ANGELES AND LONDON
Characteristic	Los Angeles
Air temperature	From 24 to 32° C	From -1 to 4° C
Relative humidity		85% (+ fog)
Temperature inversion	At an altitude of 1000 m	At an altitude of several hundred meters
Wind speed		No wind
Visibility	<0,8-1,6 км
Months of most frequent occurrence	Aug. Sept	December - January
Basic fuels		Coal (and gasoline)
Main components	O3, NO, NO2, CO, organic matter	Fine particles, CO, sulfur compounds
Type of chemical reactions	Recovery
Time of maximum condensation		Early morning
Main health effects	Eye irritation, breathing problems	Respiratory irritation
Most damaged materials		Iron, concrete

METHODS OF COMBATING SMOG

Smog poses a great danger to the entire biosphere. Combating it is one of the most important tasks in solving the environmental issue.

At the city level, the fight against smog consists of adopting various legislative measures that oblige industrial enterprises to strictly control the substances they emit into the atmosphere, reduce total emissions from cars by limiting their presence in the city, and calling for the abandonment of personal vehicles. The main methods today to reduce air pollution, including acid-forming emissions, are the development and implementation of various treatment facilities and legal protection of the atmosphere.

Research is underway to reduce pollution from vehicle exhaust. The replacement of gasoline in cars with other types of fuel (for example, a mixture of alcohols), the use of gas-cylinder cars using natural gas, and electric vehicles are promising;

The share of smog created by industry can be reduced with the help of dust collectors if enterprises are equipped with them. Using special filters is effective. Advantages of filters: high efficiency in terms of extracted components (90-98%); simplicity and compactness; minimum level of energy consumption for cleaning (from 1.5 to 4.5 kW/day); reliability in operation, high degree of maintainability; low sensitivity to concentration fluctuations.

For medium and small energy enterprises, use the fluidized bed combustion method, which removes up to 95% of sulfur dioxide and from 50 to 75% of nitrogen oxides. The technology for reducing the content of nitrogen oxides (by 50-60%) by reducing the combustion temperature has been well developed. Use of natural gas as fuel in power plants. Renewable, environmentally friendly energy resources, such as solar energy, wind, sea tides, and thermal springs from the Earth’s interior, can actually replace fossil fuels.

Local protection from smog is a person’s personal contribution to air purification and, accordingly, to their own health. This is achieved by the principled use of environmentally friendly equipment and fuel, and the purchase of household products that are safe for the environment and your health. Reducing energy consumption may also play a role.

There are quite a few methods of control, but almost each of them has its own disadvantages, and some methods are completely ineffective.

We will not be able to completely get rid of smog, because to do this we need to switch all transport to environmentally friendly fuel, install treatment facilities at all plants and factories, significantly reduce the amount of evaporation of harmful gases, but it is quite possible to take less radical measures to clean the biosphere from its harmful effects .

The greatest difficulty in research to reduce pollution from exhaust gases is the reduction of emissions of nitrogen oxides, which, in addition to the formation of acid precipitation, are responsible for the appearance of photochemical pollutants (photochemical smog) and the destruction of the ozone layer in the stratosphere. To solve this problem, work is underway to create various catalytic converters that convert nitrogen oxides into molecular nitrogen.

Creating waste-free production in all industries requires solving a number of complex engineering and technological problems and huge capital investments.

The sulfur content of emissions can be reduced by using low-sulfur coal and by physically or chemically washing it. But physical cleaning methods are unprofitable. Chemical cleaning method: in various filters and purifiers, combustion gases are passed through an aqueous solution of lime, resulting in the formation of insoluble calcium sulfate CaSO4. This method allows you to remove up to 95% of SO2, but is expensive (lowering the temperature of flue gases and reducing draft requires additional energy for heating them; in addition, the problem of recycling CaSO4 arises) and is economically effective only when constructing new large enterprises.

smog pollution photochemical

CONCLUSION

It turns out that living in large cities was already deadly in the 13th century, when coal was used to heat homes. It is not difficult to imagine what is happening in our time of power and speed.

Atmospheric pollution from automobile exhaust emissions increases with the increase in the number of cars themselves. And in the near future, a complete replacement of gasoline with other types of fuel is not expected. This means that we cannot avoid photochemical smog in the summer.

I would like to believe that with the onset of autumn and winter the air will be cleaner, but no, the heating season is coming. And although in modern times coal is not used everywhere, it has been replaced by hydrocarbons, the combustion of which also causes smog.

And people who suffer from smog are most often the most defenseless - children and the elderly. While preparing the material for the essay, I discovered data that the causeless whims of children and attacks of aggression in pets are also consequences of smog.

To reduce the effects of smog, you need to try not to go outside during it, drink green tea or herbal teas, and eat more fresh vegetables and fruits.

If possible, it is better to leave the city during the smog.

BIBLIOGRAPHY

Opalovsky A.A. Planet Earth through the eyes of a chemist. M., Nauka, 1990

Revel P., Revel Ch. Our habitat. In four books (translation from English). M., Mir, 1995

Chemistry and society (translation from English). M., Mir, 1995

Dobrovolsky V.V. Fundamentals of biogeochemistry. Textbook manual for geogr., biol., geol., agricultural. specialist. universities M., Higher school, 1998

Andruz J., Brimblecoomb P., Jickels T., Liss P. Introduction to environmental chemistry (translation from English) M., Mir, 1999

20Feb

Smog- air pollution with microscopic particles of various substances that impede visibility and pose a danger to human health and other living beings.

words - “could”.

This term was introduced in 1905. Doctor Harold Antoine des Voeux I wanted to come up with a word to describe the heavy London fog. He created from two words: smoke ( smoke) and fog ( fog) forming the word – smog. This term was quickly picked up and circulated by newspapermen, which in turn made this word very popular. It should be noted that this term described not just thick natural fog, but one caused by pollution and emissions from coal burning in London factories.

Causes of smog.

There are two types of “heavy fog”: natural and man-made.

Natural smog includes pollution caused by a volcanic eruption or a large forest fire. History knows a lot of examples when, due to such smog, air traffic between airports is stopped.

Man-made smog is a type of pollution that occurs due to human economic activity. This type includes fog formed from emissions from various plants and factories, cars and similar sources of pollution.

Smog and its dangers.

Smog as a phenomenon has a very negative impact on people's health. It is most dangerous for children and the elderly. People with respiratory diseases have difficulty breathing. The mucous membrane of the eyes and nose becomes irritated, which in turn causes pain and discomfort. In addition to the danger to humans, smog poses a threat to animals and plants. Persistent pollution can damage crops and the health of farm and wildlife animals.