Harmful substances. Emissions of harmful substances into the atmosphere

Industrial and economic development is usually accompanied by an increase in environmental pollution. Most large cities are characterized by a significant concentration of industrial facilities in relatively small areas, which poses a danger to human health.

One of the environmental factors that has the most pronounced impact on human health is air quality. At present, emissions of pollutants into the atmosphere pose a particular danger. This is due to the fact that toxicants enter the human body mainly through the respiratory tract.

Air emissions: sources

There are natural and anthropogenic sources of air pollutants. The main impurities that contain atmospheric emissions from natural sources are dust of cosmic, volcanic and plant origin, gases and smoke generated as a result of forest and steppe fires, products of destruction and weathering of rocks and soils, etc.

Levels of air pollution from natural sources are background. They change quite little over time. The main sources of pollutants entering the air at the present stage are anthropogenic, namely industry (various industries), agriculture and motor transport.

Emissions from enterprises into the atmosphere

The largest “suppliers” of various pollutants into the air are metallurgical and energy enterprises, chemical production, the construction industry, and mechanical engineering.

During the combustion of various types of fuel by energy complexes, large amounts of sulfur dioxide, carbon and nitrogen oxides, and soot are released into the atmosphere. A number of other substances, in particular hydrocarbons, are also present in emissions (in smaller quantities).

The main sources of dust and gas emissions in metallurgical production are melting furnaces, casting plants, pickling departments, sintering machines, crushing and grinding equipment, unloading and loading of materials, etc. The largest share among the total amount of substances entering the atmosphere is occupied by carbon monoxide, dust, sulfur dioxide, Nitric oxide. Manganese, arsenic, lead, phosphorus, mercury vapor, etc. are released in slightly smaller quantities. Also, during the steelmaking process, emissions into the atmosphere contain steam-gas mixtures. They contain phenol, benzene, formaldehyde, ammonia and a number of other hazardous substances.

Harmful emissions into the atmosphere from chemical industry enterprises, despite their small volumes, pose a particular danger to the natural environment and humans, since they are characterized by high toxicity, concentration and significant diversity. The mixtures entering the air, depending on the type of product being manufactured, may contain volatile organic compounds, fluorine compounds, nitrous gases, solids, chloride compounds, hydrogen sulfide, etc.

During the production of building materials and cement, emissions into the atmosphere contain significant amounts of various dusts. The main technological processes leading to their formation are grinding, processing of charges, semi-finished products and products in streams of hot gases, etc. Around factories producing various building materials, contamination zones with a radius of up to 2000 m can form. They are characterized by a high concentration of dust containing particles of gypsum, cement, quartz, as well as a number of other pollutants.

Vehicle emissions

In large cities, a huge amount of pollutants into the atmosphere comes from vehicles. According to various estimates, their share accounts for from 80 to 95%. consist of a large number of toxic compounds, in particular nitrogen and carbon oxides, aldehydes, hydrocarbons, etc. (about 200 compounds in total).

The greatest volumes of emissions are observed in areas where traffic lights and intersections are located, where cars move at low speeds and in idling mode. Calculation of emissions into the atmosphere shows that the main components of the exhaust in this case are hydrocarbons.

It should be noted that, in contrast to stationary sources of emissions, the operation of motor vehicles leads to air pollution on city streets at the height of human growth. As a result, pedestrians, residents of houses located near roads, as well as vegetation growing in adjacent areas are exposed to harmful effects of pollutants.

Agriculture

Impact on humans

According to various sources, there is a direct link between air pollution and a number of diseases. For example, the duration of respiratory diseases in children who live in relatively polluted areas is 2-2.5 times longer than in those living in other areas.

In addition, in cities characterized by unfavorable environmental conditions, children have functional deviations in the immune system and blood formation, and violations of compensatory and adaptive mechanisms to environmental conditions. Many studies have also revealed a connection between air pollution and human mortality.

The main components of emissions entering the air from various sources are suspended substances, oxides of nitrogen, carbon and sulfur. It was revealed that zones exceeding the maximum permissible concentrations for NO 2 and CO cover up to 90% of the urban area. The given macrocomponents of emissions can cause serious illnesses. The accumulation of these contaminants leads to damage to the mucous membranes of the upper respiratory tract and the development of pulmonary diseases. In addition, increased concentrations of SO 2 can cause degenerative changes in the kidneys, liver and heart, and NO 2 - toxicosis, congenital anomalies, heart failure, nervous disorders, etc. Some studies have revealed a relationship between the incidence of lung cancer and the concentrations of SO 2 and NO 2 in the air.

conclusions

Pollution of the natural environment and, in particular, the atmosphere, has adverse consequences for the health of not only the present, but also subsequent generations. Therefore, we can safely say that the development of measures aimed at reducing emissions of harmful substances into the atmosphere is one of the most pressing problems of humanity today.

MINISTRY OF EDUCATION AND SCIENCE

RUSSIAN FEDERATION

STATE EDUCATIONAL INSTITUTION

HIGHER PROFESSIONAL EDUCATION

"MOSCOW STATE UNIVERSITY

FOOD PRODUCTION"

O.V. Gutina, Malofeeva Yu.N.

EDUCATIONAL AND METHODOLOGICAL MANUAL for solving problems in the course

"ECOLOGY"

for students of all specialties

Moscow 2006

1. Monitoring the quality of atmospheric air in the area of industrial enterprises.
Task 1. Calculation of flue gas dispersion from a boiler room pipe
2. Technical means and methods of protecting the atmosphere.
Task 2.
3. Pollution control. Regulatory and legal framework for nature conservation. Payment for environmental damage.
Task 3. “Calculation of technological emissions and payment for pollution of hazardous pollutants using the example of a bakery plant”

Literature

Dispersion of emissions from industrial enterprises in the atmosphere

Emissions are the entry of pollutants into the atmosphere. The quality of atmospheric air is determined by the concentration of pollutants contained in it, which should not exceed the sanitary and hygienic standard - the maximum permissible concentration (MAC) for each pollutant. MPC is the maximum concentration of a pollutant in the atmospheric air, related to a certain averaging time, which, with periodic exposure or throughout a person’s entire life, does not have a harmful effect on him, including long-term consequences.

With existing technologies for obtaining target products and existing methods for purifying emissions, reducing the concentrations of hazardous pollutants in the environment is ensured by increasing the dispersion area by removing emissions to a greater height. It is assumed that only such a level of aerotechnogenic environmental pollution is achieved at which natural self-purification of the air is still possible.

The highest concentration of each harmful substance is C m (mg/m 3) in the ground layer of the atmosphere should not exceed the maximum permissible concentration:

If the emission includes several harmful substances with a unidirectional effect, i.e. mutually reinforce each other, then the inequality must be satisfied:

(2)

C 1 - C n – actual concentration of a harmful substance in the atmosphere

air, mg/m3,

MPC - maximum permissible concentrations of pollutants (MP).

Scientifically based MPC standards in the surface layer of the atmosphere must be ensured by control of standards for all emission sources. This environmental standard is maximum permissible emission

MPE - the maximum emission of a pollutant, which, when dissipated in the atmosphere, creates a ground-level concentration of this substance that does not exceed the maximum permissible concentration, taking into account the background concentration.

Environmental pollution due to dispersion of industrial emissions through high chimneys depends on many factors: the height of the pipe, the speed of the emitted gas flow, the distance from the emission source, the presence of several nearby emission sources, meteorological conditions, etc.

Emission height and gas flow velocity. As the height of the pipe and the speed of the emitted gas flow increase, the efficiency of contaminant dispersion increases, i.e. dispersion of emissions occurs in a larger volume of atmospheric air, over a larger area of the earth's surface.

Wind speed. Wind is the turbulent movement of air over the surface of the earth. The direction and speed of the wind do not remain constant; the wind speed increases as the difference in atmospheric pressure increases. The greatest air pollution is possible with weak winds of 0-5 m/s when emissions are dissipated at low altitudes in the surface layer of the atmosphere. For emissions from high sources least e dispersion of contaminants occurs at wind speeds of 1-7 m/s (depending on the speed of exit of the gas stream from the mouth of the pipe).

Temperature stratification. The ability of the earth's surface to absorb or radiate heat affects the vertical distribution of temperature in the atmosphere. Under normal conditions When you rise up 1 km, the temperature decreases by 6,5 0 : temperature gradient is 6,5 0 /km. In real conditions, deviations from a uniform decrease in temperature with height may be observed - temperature inversion. Distinguish surface and elevated inversions. Surface ones are characterized by the appearance of a warmer layer of air directly at the surface of the earth, elevated ones are characterized by the appearance of a warmer layer of air (inversion layer) at a certain height. In inversion conditions, the dispersion of pollution worsens; they are concentrated in the surface layer of the atmosphere. When a polluted gas stream is released from a high source, the greatest air pollution is possible with an elevated inversion, the lower boundary of which is located above the source of the release and the most dangerous wind speed is 1 - 7 m/s. For low emission sources, the combination of a surface inversion with weak winds is most unfavorable.

Terrain. Even in the presence of relatively small elevations, the microclimate in certain areas and the nature of the dispersion of pollution change significantly. Thus, in low places, stagnant, poorly ventilated zones with an increased concentration of pollutants are formed. If there are buildings in the path of the polluted flow, then above the building the air flow speed increases, immediately behind the building it decreases, gradually increasing with distance, and at some distance from the building the air flow speed takes on its original value. Aerodynamic shadow – a poorly ventilated area formed when air flows around a building. Depending on the type of building and the nature of the development, various zones with closed air circulation are formed, which can have a significant impact on the distribution of pollution.

Methodology for calculating the dispersion of harmful substances in the atmosphere contained in emissions , is based on determining the concentrations of these substances (mg/m 3) in the ground layer of air. Danger level pollution of the ground layer of atmospheric air by emissions of harmful substances is determined by the highest calculated value of the concentration of harmful substances, which can be established at some distance from the source of the emission under the most unfavorable weather conditions (wind speed reaches a dangerous value, intense turbulent vertical exchange is observed, etc.).

Calculation of emission dispersion is carried out according toOND-86.

The maximum surface concentration is determined by the formula:

(3)

A – coefficient depending on the temperature stratification of the atmosphere (the value of coefficient A is taken equal to 140 for the Central region of the Russian Federation).

M – emission power, mass of pollutant emitted per unit time, g/s.

F is a dimensionless coefficient that takes into account the rate of deposition of harmful substances in the atmosphere (for gaseous substances it is equal to 1, for solid substances - 1).

 is a dimensionless coefficient that takes into account the influence of terrain (for flat terrain - 1, for rough terrain - 2).

H – height of the emission source above ground level, m.

 – the difference between the temperature emitted by the gas-air mixture and the temperature of the surrounding outside air.

V 1 – flow rate of the gas-air mixture leaving the emission source, m 3 /s.

m, n – coefficients taking into account the release conditions.

Enterprises that emit harmful substances into the environment must be separated from residential buildings by sanitary protection zones. The distance from the enterprise to residential buildings (the size of the sanitary protection zone) is established depending on the amount and type of pollutants emitted into the environment, the capacity of the enterprise, and the features of the technological process. Since 1981 The calculation of the sanitary protection zone is regulated by state standards. SanPiN 2.2.1/2.1.1.1200-03 “Sanitary protection zones and sanitary classification of enterprises, structures and other objects.” According to it, all enterprises are divided into 5 classes according to their degree of danger. And depending on the class, the standard value of the sanitary protection zone is established.

Enterprise (class) Dimensions of the sanitary protection zone

I class 1000 m

II class 500 m

III class 300 m

IV class 100 m

V class 50

One of the functions of the sanitary protection zone is the biological purification of atmospheric air using landscaping. Trees and shrubs for gas absorption purposes (phytofilters) capable of absorbing gaseous pollutants. For example, it has been established that meadow and woody vegetation can bind 16-90% of sulfur dioxide.

Task No. 1: The boiler room of an industrial enterprise is equipped with a boiler unit that runs on liquid fuel. Combustion products: carbon monoxide, nitrogen oxides (nitrogen oxide and nitrogen dioxide), sulfur dioxide, fuel oil ash, vanadium pentoxide, benzopyrene, and sulfur dioxide and nitrogen dioxide have a unidirectional effect on the human body and form a summation group.

The task requires:

1) find the maximum ground concentration of sulfur dioxide and nitrogen dioxide;

2) the distance from the pipe to the place where S M appears;

Initial data:

Boiler room productivity – Q about =3000 MJ/h;

Fuel – sulphurous fuel oil;

Efficiency of the boiler installation –  k.u. =0.8;

Chimney height H=40 m;

Chimney diameter D=0.4m;

Release temperature T g =200С;

Outside air temperature T = 20С;

Quantity of exhaust gases from 1 kg of burned fuel oil V g = 22.4 m 3 /kg;

Maximum permissible concentration of SO 2 in atmospheric air –

With PDK a.v. =0.05 mg/m3;

Maximum permissible concentration of NO 2 in atmospheric air –

With PDK a.v. =0.04 mg/m3;

Background concentration of SO 2 – C f =0.004 mg/m 3 ;

Heat of combustion of fuel Q n =40.2 MJ/kg;

The location of the boiler room is Moscow region;

The terrain is calm (with a height difference of 50m per 1km).

The calculation of the maximum surface concentration is carried out in accordance with the regulatory document OND-86 “Methodology for calculating concentrations in the atmospheric air of pollutants contained in emissions from enterprises.”

C M =
,

 =Т Г – Т В = 200 – 20 = 180 о С.

To determine the consumption of the gas-air mixture, we find the hourly fuel consumption:

In h =

V 1 =

m – dimensionless coefficient depending on the release conditions: the exit velocity of the gas-air mixture, the height and diameter of the release source and the temperature difference.

f =

the exit speed of the gas-air mixture from the mouth of the pipe is determined by the formula:

 o =

f= 1000

n – dimensionless coefficient depending on the release conditions: volume of the gas-air mixture, height of the release source and temperature difference.

Determined by characteristic value

V M = 0.65

n = 0.532V m 2 – 2.13V m + 3.13 = 1.656

M = V 1  a, g/s,

M SO 2 = 0.579  3 = 1.737 g/s,

M NO 2 =0.8  0.579 = 0.46 g/s.

Maximum ground concentration:

sulfur dioxide -

C M =

nitrogen dioxide -

Cm = .

We find the distance from the pipe to the place where C M appears using the formula:

X M =

where d is a dimensionless coefficient depending on the release conditions: the exit velocity of the gas-air mixture, the height and diameter of the release source, the temperature difference and the volume of the gas-air mixture.

d = 4.95V m (1 + 0.28f), at 0.5 V M  2,

d = 7 V M (1 + 0.28f), with V M  2.

We have V M = 0.89  d = 4.95 0.89(1 + 0.280.029) = 4.7

X M =

Because If the ground level concentration of sulfur dioxide exceeds the maximum permissible concentration of sulfur dioxide in atmospheric air, then the value of the maximum permissible concentration of sulfur dioxide for the source in question is determined, taking into account the need to fulfill the summation equation

Substituting our values, we get:

which is greater than 1. To satisfy the conditions of the summation equation, it is necessary to reduce the mass of sulfur dioxide emission, while maintaining the emission of nitrogen dioxide at the same level. Let's calculate the ground level concentration of sulfur dioxide at which the boiler house will not pollute the environment.

=1- = 0,55

C SO2 = 0.55  0.05 = 0.0275 mg/m 3

The efficiency of the purification method, ensuring a reduction in the mass of sulfur dioxide emissions from the initial value M = 1.737 g/s to 0.71 g/s, is determined by the formula:

where СВХ is the concentration of the pollutant at the inlet to the gas treatment plant

installation, mg/m 3,

C OUT – concentration of the pollutant at the outlet of the gas

treatment plant, mg/m3.

Because
, A
, That

then the formula will take the form:

Therefore, when choosing a cleaning method, it is necessary that its efficiency be at least 59%.

Technical means and methods of protecting the atmosphere.

Emissions from industrial enterprises are characterized by a wide variety of dispersed composition and other physicochemical properties. In this regard, various methods for their purification and types of gas and dust collectors - devices designed to purify emissions from pollutants - have been developed.

M
methods for cleaning industrial emissions from dust can be divided into two groups: dust collection methods "dry" method and dust collection methods "wet" method. Gas dust removal devices include: dust settling chambers, cyclones, porous filters, electric precipitators, scrubbers, etc.

The most common dry dust collection installations are cyclones various types.

They are used to capture flour and tobacco dust, ash formed when burning fuel in boiler units. The gas flow enters the cyclone through pipe 2 tangentially to the inner surface of housing 1 and performs a rotational-translational motion along the housing. Under the influence of centrifugal force, dust particles are thrown to the wall of the cyclone and, under the influence of gravity, fall into the dust collection hopper 4, and the purified gas exits through the outlet pipe 3. For normal operation of the cyclone, its tightness is necessary; if the cyclone is not sealed, then due to suction outside air, dust is carried out with a flow through the outlet pipe.

The tasks of cleaning gases from dust can be successfully solved by cylindrical (TsN-11, TsN-15, TsN-24, TsP-2) and conical (SK-TsN-34, SK-TsN-34M, SKD-TsN-33) cyclones, developed by the Research Institute for Industrial and Sanitary Gas Purification (NIIOGAZ). For normal operation, the excess pressure of gases entering the cyclones should not exceed 2500 Pa. In this case, in order to avoid condensation of liquid vapors, the temperature of the gas is selected to be 30 - 50 o C above the t dew point, and according to the conditions of structural strength - no higher than 400 o C. The productivity of the cyclone depends on its diameter, increasing with the growth of the latter. The cleaning efficiency of cyclones of the TsN series decreases with increasing angle of entry into the cyclone. As the particle size increases and the cyclone diameter decreases, the cleaning efficiency increases. Cylindrical cyclones are designed to collect dry dust from aspiration systems and are recommended for use for pre-cleaning of gases at the inlet of filters and electric precipitators. Cyclones TsN-15 are made of carbon or low-alloy steel. Canonical cyclones of the SK series, designed for cleaning gases from soot, have increased efficiency compared to cyclones of the TsN type due to greater hydraulic resistance.

To purify large masses of gases, battery cyclones are used, consisting of a large number of parallel installed cyclone elements. Structurally, they are combined into one housing and have a common gas supply and outlet. Experience in operating battery cyclones has shown that the cleaning efficiency of such cyclones is somewhat lower than the efficiency of individual elements due to the flow of gases between the cyclone elements. The domestic industry produces battery cyclones such as BC-2, BTsR-150u, etc.

Rotary Dust collectors are centrifugal devices that, while moving air, clean it from dust fractions larger than 5 microns. They are very compact, because... the fan and dust collector are usually combined in one unit. As a result, during the installation and operation of such machines, no additional space is required to accommodate special dust collection devices when moving a dusty flow with an ordinary fan.

The design diagram of the simplest rotary type dust collector is shown in the figure. When the fan wheel 1 operates, dust particles, due to centrifugal forces, are thrown towards the wall of the spiral casing 2 and move along it in the direction of the exhaust hole 3. The dust-enriched gas is discharged through a special dust receiving hole 3 into the dust bin, and the purified gas enters the exhaust pipe 4 .

To increase the efficiency of dust collectors of this design, it is necessary to increase the portable speed of the purified flow in the spiral casing, but this leads to a sharp increase in the hydraulic resistance of the device, or to reduce the radius of curvature of the casing spiral, but this reduces its productivity. Such machines provide a fairly high efficiency of air purification while capturing relatively large dust particles - over 20 - 40 microns.

More promising rotary dust separators, designed to clean air from particles  5 µm in size, are counter-flow rotary dust separators (RPD). The dust separator consists of a hollow rotor 2 with a perforated surface built into the casing 1 and a fan wheel 3. The rotor and fan wheel are mounted on a common shaft. When the dust separator operates, dusty air enters the housing, where it swirls around the rotor. As a result of the rotation of the dust flow, centrifugal forces arise, under the influence of which suspended dust particles tend to separate from it in the radial direction. However, aerodynamic drag forces act on these particles in the opposite direction. Particles whose centrifugal force is greater than the aerodynamic drag force are thrown toward the walls of the casing and enter hopper 4. The purified air is thrown out through the perforation of the rotor using a fan.

The efficiency of PRP cleaning depends on the selected ratio of centrifugal and aerodynamic forces and theoretically can reach 1.

A comparison of PDPs with cyclones demonstrates the advantages of rotary dust collectors. Thus, the overall dimensions of the cyclone are 3–4 times, and the specific energy consumption for cleaning 1000 m 3 of gas is 20–40% higher than that of the PRP, all other things being equal. However, rotary dust collectors are not widely used due to the relative complexity of the design and operating process compared to other devices for dry gas purification from mechanical contaminants.

To separate the gas flow into purified gas and dust-enriched gas, use louvered dust separator On the louvre grille 1, the gas flow with flow rate Q is divided into two flow paths with flow rates Q 1 and Q 2. Usually Q 1 = (0.8-0.9)Q, and Q 2 = (0.1-0.2)Q. The separation of dust particles from the main gas flow on the louvre grille occurs under the influence of inertial forces that arise when the gas flow turns at the entrance to the louvre grille, as well as due to the effect of reflection of particles from the surface of the grille upon impact. The dust-enriched gas flow after the louvered grille is directed to a cyclone, where it is cleaned of particles, and is reintroduced into the pipeline behind the louvered grille. Louvre dust separators are simple in design and are well arranged in gas ducts, providing a cleaning efficiency of 0.8 or more for particles larger than 20 microns. They are used to clean flue gases from coarse dust at temperatures up to 450 – 600 o C.

Electric precipitator. Electrical cleaning is one of the most advanced types of gas purification from suspended particles of dust and fog. This process is based on impact ionization of gas in the corona discharge zone, transfer of ion charge to impurity particles and deposition of the latter on collecting and corona electrodes. Precipitation electrodes 2 are connected to the positive pole of the rectifier 4 and grounded, and the corona electrodes are connected to the negative pole. The particles entering the electrostatic precipitator are connected to the positive pole of the rectifier 4 and are grounded, and the corona electrodes are charged with ion impurity ions. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 usually already have a small charge obtained due to friction against the walls of pipelines and equipment. Thus, negatively charged particles move towards the collection electrode, and positively charged particles settle on the negative discharge electrode.

Filters widely used for fine purification of gas emissions from impurities. The filtration process consists of retaining impurity particles on porous partitions as they move through them. The filter consists of housing 1, separated by a porous partition (filter-

Atmospheric air is the most important natural environment for human life. In this article we will talk about how emissions of substances into the atmosphere affect the composition and quality of air, what threatens air pollution and how to counter it.

What is atmosphere

From the school physics course we know that the atmosphere is the gaseous shell of the planet Earth. The atmosphere consists of two parts: upper and lower. The lower part of the atmosphere is called the troposphere. It is in the lower part of the atmosphere that the bulk of atmospheric air is concentrated. Processes occur here that influence weather and climate at the surface of the earth. These processes change the composition and quality of air. Processes of emission of substances into the atmosphere take place on earth. As a result of these emissions, solid particles enter the atmosphere: dust, ash and volatile gaseous chemicals: sulfur oxides, nitrogen oxides, carbon oxides, hydrocarbons.

Classification of substance release processes

Natural sources of substance release

The release of substances into the atmosphere can occur as a result of natural phenomena. Imagine what a huge amount of harmful gases and ash is released into the atmosphere by an awakened volcano. And all these substances are carried by air currents throughout the globe. A forest fire or dust storm also harms the environment and atmosphere. Of course, nature takes a long time to recover after such natural disasters.

Anthropogenic sources of substance emissions

The bulk of substances emitted into the atmosphere are created by humans. Man began to influence nature the moment he learned to make fire. But the smoke that appeared along with the fire did not cause much harm to nature. Over time, humanity invented machines. Manufacturing and industrial enterprises appeared, and the automobile was invented. A plant or factory produced products. But along with the products, harmful substances were produced and released into the atmosphere.

Nowadays, the main sources of emissions into the atmosphere are industrial enterprises, boiler houses, and transport. The greatest damage to the environment is caused by enterprises that produce metal and enterprises that produce chemical products.

Production processes related to fuel combustion

Thermal power plants, metallurgical and chemical plants, boiler plants for solid and liquid fuels burn fuel and, along with smoke, emit sulfur dioxide and carbon dioxide, hydrogen sulfide, chlorine, fluorine, ammonia, phosphorus compounds, particles and compounds of mercury and arsenic, and nitrogen oxides into the atmosphere. Harmful substances are also present in the exhaust of cars and modern turbojet aircraft.

Production processes not related to fuel combustion

Production processes such as quarrying, blasting, emissions from ventilation shafts in mines, emissions from nuclear reactors, and production of building materials occur without burning fuel, but harmful substances are released into the atmosphere in the form of dust and toxic gases. Chemical production is considered particularly dangerous due to the possibility of emergency emissions into the atmosphere of oxides of sulfur, nitrogen, carbon, dust and soot, organochlorine and nitro compounds, and man-made radionuclides, which are considered very toxic substances.

Substances released into the atmosphere are carried over long distances. Such substances can mix with the air of the lower layers of the atmosphere and are called primary chemical compounds. If primary substances enter into chemical reactions with the main components of air - oxygen, nitrogen and water vapor, then photochemical oxidizers and acids are formed, which are called secondary pollutants. They can cause acid rain, photochemical smog and the formation of ozone in the atmosphere. It is secondary pollutants that are especially dangerous to humans and the environment.

How to protect the environment from pollution? One of the methods to solve this problem is to purify substances emitted into the atmosphere using special chemical devices. This will not solve the problem completely, but it will minimize the harm caused to nature by harmful substances that are formed as a result of human activity.

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Ministry of Education for Sciences of the Russian Federation

Federal State Budgetary Educational Institution

higher professional education

"Transbaikal State University"

Faculty of Physical Culture and Sports

Extramural

Direction 034400 physical education for persons with health conditions (Adaptive physical education)

Topic: Emissions of harmful substances into the atmosphere

Completed:

Levintsev A.P.

Student of the group AFKz-14-1

Checked:

Assistant of the department of technical and physical safety

Zoltuev A.V.

2014, Chita

Introduction

Conclusion

Introduction

atmosphere pollution emissions transport

The rapid growth of humankind and its scientific and technological equipment has radically changed the situation on Earth. If in the recent past all human activity manifested itself negatively only in limited, albeit numerous territories, and the force of impact was incomparably less than the powerful cycle of substances in nature, now the scales of natural and anthropogenic processes have become comparable, and the ratio between them continues to change with acceleration towards increasing power of anthropogenic influence on the biosphere.

The danger of unpredictable changes in the stable state of the biosphere, to which natural communities and species, including man himself, have historically been adapted, is so great while maintaining the usual methods of management that the current generations of people inhabiting the Earth have been faced with the task of urgent improvement of all aspects of their lives in accordance with the need maintaining the existing circulation of substances and energy in the biosphere. In addition, widespread pollution of our environment with various substances, sometimes completely alien to the normal existence of the human body, poses a serious danger to our health and the well-being of future generations.

Sources of air pollution

Natural sources of pollution include: volcanic eruptions, dust storms, forest fires, dust of cosmic origin, sea salt particles, products of plant, animal and microbiological origin. The level of such pollution is considered as background, which changes little over time.

The main natural process of pollution of the surface atmosphere is the volcanic and fluid activity of the Earth. Large volcanic eruptions lead to global and long-term pollution of the atmosphere. This is due to the fact that huge amounts of gases are instantly released into the high layers of the atmosphere, which are picked up at high altitudes by air currents moving at high speeds and quickly spread throughout the globe. The duration of the polluted state of the atmosphere after large volcanic eruptions reaches several years.

Anthropogenic sources of pollution are caused by human economic activities. These include:

1. Combustion of fossil fuels, which is accompanied by the release of carbon dioxide

2. Operation of thermal power plants, when the combustion of high-sulfur coals results in the formation of acid rain as a result of the release of sulfur dioxide and fuel oil.

3. Exhausts from modern turbojet aircraft contain nitrogen oxides and gaseous fluorocarbons from aerosols, which can lead to damage to the ozone layer of the atmosphere (ozonosphere).

4. Production activities.

5. Pollution with suspended particles (during grinding, packaging and loading, from boiler houses, power plants, mine shafts, quarries when burning waste).

6. Emissions of various gases by enterprises.

7. Combustion of fuel in flare furnaces.

8. Combustion of fuel in boilers and vehicle engines, accompanied by the formation of nitrogen oxides, which cause smog.

During fuel combustion processes, the most intense pollution of the surface layer of the atmosphere occurs in megalopolises and large cities, industrial centers due to the widespread use of vehicles, thermal power plants, boiler houses and other power plants operating on coal, fuel oil, diesel fuel, natural gas and gasoline. The contribution of motor transport to total air pollution here reaches 40-50%. A powerful and extremely dangerous factor in air pollution are disasters at nuclear power plants (Chernobyl accident) and testing of nuclear weapons in the atmosphere. This is due both to the rapid spread of radionuclides over long distances and to the long-term nature of contamination of the territory.

Classification of pollutants

Pollution is one of the types of ecosystem degradation. Environmental pollution is the anthropogenic introduction of agents of various natures into the ecosystem, the impact of which on living organisms exceeds the natural level. These agents may include those inherent to the ecosystem and those alien to it. In accordance with this definition, pollution is classified according to the type of impact, the method of entry of active agents into the environment and the nature of the impact on it. The following types of environmental pollution are distinguished:

1) mechanical - environmental pollution by agents that have a mechanical effect (for example, littering with various types of garbage);

2) chemical - pollution with chemicals that have a toxic effect on living organisms or cause deterioration of the chemical properties of environmental objects;

3) physical - anthropogenic impact that causes negative changes in the physical properties of the environment (thermal, light, noise, electromagnetic, etc.);

4) radiation - anthropogenic impact of ionizing radiation from radioactive substances exceeding the natural level of radioactivity;

5) biological pollution is very diverse and includes:

a) introducing into the ecosystem alien living organisms (animals, plants, microorganisms),

b) supply of nutrients;

c) the introduction of organisms that cause an imbalance in populations;

d) anthropogenic disruption of the original state of living organisms inherent in the ecosystem (for example, mass reproduction of microorganisms or a negative change in their properties).

Air pollution from transport emissions

A large share of air pollution comes from emissions of harmful substances from cars. The total number of vehicles, including cars, trucks of various classes (excluding heavy off-road vehicles) and buses, was 1.015 billion units in 2010. Moreover, in 2009, the total number of registered cars was much lower - 980 million. For comparison: in 1986, this number was “only” 500 million. Currently, road transport accounts for more than half of all harmful emissions into the environment, which are the main source of air pollution, especially in large cities. On average, with a mileage of 15 thousand km per year, each car burns 2 tons of fuel and about 26 - 30 tons of air, including 4.5 tons of oxygen, which is 50 times more than human needs. At the same time, the car emits into the atmosphere (kg/year): carbon monoxide - 700, nitrogen dioxide - 40, unburned hydrocarbons - 230 and solids - 2 - 5. In addition, many lead compounds are emitted due to the use of mostly leaded gasoline .

Observations have shown that in houses located next to a major road (up to 10 m), residents suffer from cancer 3-4 times more often than in houses located 50 m away from the road. Transport also poisons water bodies, soil and plants.

Toxic emissions from internal combustion engines (ICEs) are exhaust and crankcase gases, fuel vapors from the carburetor and fuel tank. The main share of toxic impurities enters the atmosphere with exhaust gases from internal combustion engines. Approximately 45% of the total hydrocarbon emissions enter the atmosphere with crankcase gases and fuel vapors.

The amount of harmful substances entering the atmosphere as part of exhaust gases depends on the general technical condition of the vehicles and, especially, on the engine - the source of the greatest pollution. Thus, if the carburetor adjustment is violated, carbon monoxide emissions increase 4-5 times. The use of leaded gasoline, which contains lead compounds, causes atmospheric air pollution with highly toxic lead compounds. About 70% of lead added to gasoline with ethyl liquid enters the atmosphere in the form of compounds with exhaust gases, of which 30% settles on the ground immediately after the cut of the vehicle's exhaust pipe, 40% remains in the atmosphere. One medium-duty truck emits 2.5-3 kg of lead per year. The concentration of lead in the air depends on the lead content in gasoline.

You can eliminate the release of highly toxic lead compounds into the atmosphere by replacing leaded gasoline with unleaded gasoline.

Atmospheric air pollution from industrial emissions

Enterprises in the metallurgical, chemical, cement and other industries emit dust, sulfur dioxide and other harmful gases into the atmosphere, released during various technological production processes. Ferrous metallurgy, smelting cast iron and processing it into steel, is accompanied by the release of various gases into the atmosphere. Air pollution with dust during coal coking is associated with the preparation of the charge and its loading into coke ovens, with the unloading of coke into quenching cars and with wet quenching of coke. Wet extinguishing is also accompanied by the release into the atmosphere of substances that are part of the water used. Non-ferrous metallurgy. When producing aluminum metal by electrolysis, a significant amount of gaseous and dusty fluoride compounds are released into the atmospheric air with waste gases from electrolysis baths. Air emissions from oil and petrochemical industries contain large amounts of hydrocarbons, hydrogen sulfide and foul-smelling gases. The release of harmful substances into the atmosphere at oil refineries occurs mainly due to insufficient sealing of equipment. For example, atmospheric air pollution with hydrocarbons and hydrogen sulfide is observed from metal tanks of raw material parks for unstable oil, intermediate and commodity parks for passenger petroleum products.

The production of cement and building materials can be a source of air pollution with various dusts. The main technological processes of these industries are grinding processes and heat treatment of charges, semi-finished products and products in hot gas streams, which is associated with dust emissions into the air. The chemical industry includes a large group of enterprises. The composition of their industrial emissions is very diverse. The main emissions from chemical industry enterprises are carbon monoxide, nitrogen oxides, sulfur dioxide, ammonia, dust from inorganic production, organic substances, hydrogen sulfide, carbon disulfide, chloride compounds, fluoride compounds, etc. Sources of air pollution in rural populated areas are livestock and poultry farms , industrial complexes from meat production, enterprises of the regional association "Agricultural Equipment", energy and heat power enterprises, pesticides used in agriculture. In the area where premises for keeping livestock and poultry are located, ammonia, carbon disulfide and other foul-smelling gases can enter the atmospheric air and spread over a considerable distance. Sources of air pollution with pesticides include warehouses, seed treatment and the fields themselves, to which pesticides and mineral fertilizers are applied in one form or another, as well as cotton gins.

The influence of air pollution on humans, flora and fauna

The mass of our planet's atmosphere is negligible - only one millionth the mass of the Earth. However, its role in the natural processes of the biosphere is enormous. The presence of an atmosphere around the globe determines the general thermal regime of the surface of our planet and protects it from harmful cosmic and ultraviolet radiation. Atmospheric circulation influences local climatic conditions, and through them, the regime of rivers, soil and vegetation cover, and the processes of relief formation.

All air pollutants, to a greater or lesser extent, have a negative impact on human health. These substances enter the human body primarily through the respiratory system. The respiratory organs suffer directly from pollution, since about 50% of impurity particles with a radius of 0.01-0.1 microns that penetrate the lungs are deposited in them.

Particles that enter the body cause a toxic effect because they:

a) toxic (poisonous) by their chemical or physical nature;

b) interfere with one or more mechanisms by which the respiratory (respiratory) tract is normally cleansed;

c) serve as a carrier of a toxic substance absorbed by the body.

In some cases, exposure to one pollutant in combination with others leads to more serious health problems than exposure to either one alone. Statistical analysis made it possible to fairly reliably establish the relationship between the level of air pollution and diseases such as damage to the upper respiratory tract, heart failure, bronchitis, asthma, pneumonia, emphysema, and eye diseases. A sharp increase in the concentration of impurities, which persists for several days, increases the mortality of older people from respiratory and cardiovascular diseases. In December 1930, the Meuse Valley (Belgium) experienced severe air pollution for 3 days; as a result, hundreds of people became ill and 60 people died—more than 10 times the average death rate. In January 1931, in the Manchester area (Great Britain), there was heavy smoke in the air for 9 days, which caused the death of 592 people.

Cases of severe air pollution in London, accompanied by numerous deaths, became widely known. In 1873, there were 268 unexpected deaths in London. Heavy smoke combined with fog between 5 and 8 December 1852 resulted in the deaths of more than 4,000 residents of Greater London. In January 1956, about 1,000 Londoners died as a result of prolonged smoke. Most of those who died unexpectedly suffered from bronchitis, emphysema or cardiovascular disease.

In cities, due to constantly increasing air pollution, the number of patients suffering from diseases such as chronic bronchitis, emphysema, various allergic diseases and lung cancer is steadily increasing. In the UK, 10% of deaths are due to chronic bronchitis, with 21 per cent of the population aged 40 to 59 suffering from the disease. In Japan, in a number of cities, up to 60% of residents suffer from chronic bronchitis, the symptoms of which are a dry cough with frequent expectoration, subsequent progressive difficulty breathing and heart failure. In this regard, it should be noted that the so-called Japanese economic miracle of the 50s and 60s was accompanied by severe pollution of the natural environment of one of the most beautiful areas of the globe and serious damage caused to the health of the population of this country. In recent decades, the number of cases of bronchial and lung cancer, caused by carcinogenic hydrocarbons, has been growing at an alarming rate.

Animals in the atmosphere and falling harmful substances are affected through the respiratory organs and enter the body along with edible dusty plants. When absorbing large quantities of harmful pollutants, animals can suffer acute poisoning. Chronic poisoning of animals with fluoride compounds is called “industrial fluorosis” among veterinarians, which occurs when animals absorb feed or drinking water containing fluoride. Characteristic signs are aging of teeth and skeletal bones.

Beekeepers in some regions of Germany, France and Sweden note that due to fluoride poisoning deposited on honey flowers, there is an increased mortality of bees, a decrease in the amount of honey and a sharp decline in the number of bee colonies.

The effect of molybdenum on ruminants was observed in England, California (USA) and Sweden. Molybdenum penetrating into the soil prevents plants from absorbing copper, and the lack of copper in food causes loss of appetite and weight in animals. When arsenic poisoning occurs, ulcers appear on the body of cattle.

In Germany, severe lead and cadmium poisoning of gray partridges and pheasants was observed, and in Austria, lead accumulated in the bodies of hares that fed on grass along highways. Three of these hares eaten in one week are enough for a person to become ill as a result of lead poisoning.

Conclusion

Today there are many environmental problems in the world: from the extinction of some species of plants and animals to the threat of degeneration of the human race. The ecological effect of polluting agents can manifest itself in different ways: it can affect either individual organisms (manifest at the organismal level), or populations, biocenoses, ecosystems and even the biosphere as a whole.

At the organismal level, there may be a violation of certain physiological functions of organisms, changes in their behavior, a decrease in the rate of growth and development, and a decrease in resistance to the effects of other unfavorable environmental factors.

At the population level, pollution can cause changes in their numbers and biomass, fertility, mortality, changes in structure, annual migration cycles and a number of other functional properties.

At the biocenotic level, pollution affects the structure and functions of communities. The same pollutants have different effects on different components of communities. Accordingly, the quantitative relationships in the biocenosis change, up to the complete disappearance of some forms and the appearance of others. Ultimately, ecosystems degrade, deteriorate as elements of the human environment, reduce their positive role in the formation of the biosphere, and depreciate in economic terms.

At the moment, there are many theories in the world in which much attention is paid to finding the most rational ways to solve environmental problems. But, unfortunately, on paper everything turns out to be much simpler than in life.

Human impact on the environment has reached alarming proportions. To fundamentally improve the situation, targeted and thoughtful actions will be needed. A responsible and effective policy towards the environment will be possible only if we accumulate reliable data on the current state of the environment, reasonable knowledge about the interaction of important environmental factors, and if we develop new methods for reducing and preventing harm caused to nature by humans.

In my opinion, to prevent further environmental pollution, it is first necessary to:

Increase attention to issues of nature conservation and ensuring the rational use of natural resources;

Establish systematic control over the use of lands, waters, forests, subsoil and other natural resources by enterprises and organizations;

Increase attention to issues of preventing pollution and salinization of soils, surface and groundwater;

Pay great attention to preserving the water protection and protective functions of forests, preserving and reproducing flora and fauna, and preventing air pollution;

Nature conservation is the task of our century, a problem that has become social. Time and again we hear about the dangers threatening the environment, but many of us still consider them an unpleasant but inevitable product of civilization and believe that we will still have time to cope with all the difficulties that have arisen. The environmental problem is one of the most important problems of humanity. And now people should understand this and take an active part in the struggle to preserve the natural environment. And everywhere: in the city of Chita, and in the Chelyabinsk region, and in Russia, and all over the world. Without the slightest exaggeration, the future of the entire planet depends on the solution to this global problem.

List of used literature

1. Kriksunov, E. A., Pasechnik, V.V., Sidorin, A.P. Ecology. Uch. allowance / Ed. E. A. Kriksunova and others - M., 1995.

2. Protasov, V.F. and others. Ecology, health and environmental management in Russia / Ed. V. F. Protasova. - M., 1995.

3. Hefling, G. Anxiety in 2000 / G. Hefling. - M., 1990.

4. Chernyak, V.Z. Seven miracles and others / V.Z. Chernyak. - M., 1983.

5. Materials from the site http:www.zr.ru were used

6. Materials from the site http:www.ecosystema.ru were used

7. Materials from the site http:www.activestudy.info.ru were used

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