Any production activity is accompanied by environmental pollution, including one of its main components – atmospheric air. Emissions industrial enterprises, power plants and transport into the atmosphere have reached such a level that pollution levels significantly exceed permissible sanitary standards.
According to GOST 17.2.1.04-77, all sources of air pollution (APP) are divided into natural and anthropogenic origin. In turn, sources of anthropogenic pollution are stationary And mobile. Mobile sources of pollution include all types of transport (with the exception of pipelines). Currently, in connection with changes in the legislation of the Russian Federation in terms of improving regulation in the field of environmental protection and introducing measures of economic incentives for business entities to implement the best technologies, it is planned to replace the concepts of “stationary source” and “mobile source”.
Stationary sources of pollution can be point, linear And areal.
Point source of pollution is a source that releases air pollutants from an installed opening (chimneys, ventilation shafts).
Linear source of pollution- this is a source that emits air pollutants along an established line (window openings, rows of deflectors, fuel racks).
Area source of pollution is a source that releases air pollutants from an installed surface ( tank farms, open evaporation surfaces, storage and transfer areas for bulk materials, etc. ) .
According to the nature of the organization of emissions, they can be organized And unorganized.
Organized Source pollution is characterized by the presence of special means for removing pollutants into environment(mines, chimneys, etc.). In addition to organized removal, there are fugitive emissions penetrating into the atmospheric air through leaks in technological equipment, openings, as a result of spillage of raw materials and supplies.
According to their purpose, IZA is divided into technological And ventilation.
Depending on the height of the mouth on the surface of the earth, there are 4 types of IZA: high (height more than 50 m), average (10 – 50 m), low(2 – 10 m) and ground (less than 2 m).
According to the mode of action, all ISAs are divided into continuous action And salvo.
Depending on the temperature difference between the emission and the surrounding atmospheric air, heated(hot) springs and cold.
Dispersion of pollutants in the atmosphere.
Initially, the pollutant emitted from the pipe is a cloud of smoke (plume). If the substance has a density less than or approximately equal to the density of air, then most likely the direction of movement of the pollutant (pollutant) will coincide with the speed and direction of air movement; if the substance is heavier than air, then it will settle. Industrial emissions are usually a mixture of air with relatively small amounts of pollutants. The most common case is the movement of a contaminated jet together with the horizontal movement of air masses.
The change in the concentration of pollutants with distance from the mouth of the source of pollution depends on the height and intensity of mixing of air masses. As you move away from the pipe, the concentration along the axis of the torch decreases, and the size of the torch in the direction perpendicular to the axis increases. The initial point of contact of a stream of polluted air with the surface of the earth is the beginning of the pollution zone, after which the concentration of pollutants above the surface of the earth begins to increase, reaching a maximum at distances of 10 - 40 pipe heights, which is associated with the fall out of the plume of impurities reaching the surface of the earth at the moment, and also impurities that previously reached the ground and continue their movement in the direction of the wind. The wind speed at a set altitude at which the surface concentration from the source of the impurity reaches its maximum value is called dangerous wind speed. When there is calm and low wind speeds, the emission plume rises to a greater height and does not fall into the ground layers of air. At strong wind the smoke plume is actively mixed with a large volume of air. Thus, between calm and high wind speed there is such a dangerous wind speed at which the smoke torch, pressing against the ground at a certain distance X m, creates the largest surface concentration With m .
After reaching the maximum value, the pollutant concentration begins, first quickly and then slowly, to decrease, usually inversely proportional to the distance from the source. The maximum concentration is directly proportional to the productivity of the source and inversely proportional to the distance from the source.
Many factors influence the dispersion of pollutants. First of all, it depends on the height of the pipe N and on the height of the rise of flue gases above the mouth of the pipe. The height of the rise of gases depends on the exit speed of the gas-air mixture 0 . Harmful substances spread in the direction of the wind within a sector limited by a rather small opening angle of the torch near the exit from the pipe of 10 - 20 °. If we assume that the opening angle does not change with distance, then the cross-sectional area of the torch should increase in proportion to the square of the distance (the torch widens).
Temperature has a strong influence on the level of surface concentration. atmospheric stratification, i.e. vertical temperature distribution. Under normal conditions, during the day the earth's surface warms up and, due to convection exchange, heats the lower ground layer of air. Under these conditions, as you rise upward, the temperature drops by 0.6 °C for every 100 m. At night, in clear weather, the surface of the earth gives off heat to the surrounding space. The earth's surface cools and, at the same time, cools the ground layer of air, which cools faster than the upper layers. As a result, an inversion (rotation) of the temperature distribution occurs. Air temperature increases with altitude.
With a normal temperature gradient, favorable conditions are created for emissions to “float up”; rising currents of warmer air intensify the mixing of gases. Under inversion conditions, these processes are weakened, which contributes to the accumulation of impurities in the surface layer.
Harmful substances emitted with flue gases are transferred and dispersed in the atmosphere depending on meteorological, climatic, terrain and the nature of the location of enterprise facilities on it, the height of chimneys and aerodynamic parameters of the emission gases.
Maximum value of ground level concentration of harmful substance With m(mg/m 3) when releasing a gas-air mixture from a single point source with a round mouth is achieved under unfavorable meteorological conditions at a distance x m(m) from the source and is determined by the formula
Where A- coefficient depending on the temperature stratification of the atmosphere; M(g/s) - the mass of a harmful substance emitted into the atmosphere per unit time; F- dimensionless coefficient taking into account the rate of deposition of harmful substances in the atmospheric air; T And n- coefficients. taking into account the conditions for the exit of the gas-air mixture from the mouth of the emission source; H(m) - height of the emission source above ground level (for ground-based sources, calculations take N= 2 m); - dimensionless coefficient that takes into account the influence of terrain, in the case of flat or slightly rough terrain with a height difference not exceeding 50 m per 1 km, = 1; T(°C) - the difference between the temperature of the emitted gas-air mixture and the temperature of the surrounding atmospheric air; V 1 (m 3 /s) - flow rate of the gas-air mixture, determined by the formula
Where D(m) - diameter of the mouth of the emission source; 0 (m/s) - average speed of exit of the gas-air mixture from the mouth of the emission source.
If the pipe has a square or rectangular mouth, then the equivalent diameter is calculated using the formula:
Where a And b are the length and width of the pipe mouth, respectively. Meaning D eq is substituted instead D into the formula.
Coefficient value A, corresponding to unfavorable meteorological conditions, under which the concentration of harmful substances in the atmospheric air is maximum, is taken to be equal to:
a) 250 - for regions of Central Asia south of 40° N. sh., Buryat Autonomous Soviet Socialist Republic and Chita region;
b) 200 - for the European territory of the USSR: for regions of the RSFSR south of 50° N. sh., for other regions of the Lower Volga region, the Caucasus, Moldova; for the Asian territory of the USSR: for Kazakhstan. the Far East and the rest of Siberia and Central Asia;
c) 180 - for the European territory of the USSR and the Urals from 50 to 52° N. w. with the exception of the areas listed above and Ukraine falling within this zone;
d) 160 - for the European territory of the USSR and the Urals north of 52° N. w. (except for the ETS Center), as well as for Ukraine (for sources located in Ukraine with a height of less than 200 m in the zone from 50 to 52° N - 180, and south of 50° N - 200);
e) 140 - for Moscow, Tula, Ryazan, Vladimir, Kaluga, Ivanovo regions.
F accepted for gaseous harmful substances and fine aerosols (dust, ash, etc., the rate of ordered sedimentation of which is practically zero) - 1; for fine aerosols with an average operational emission purification factor of at least 90% - 2; from 75 to 90% - 2.5; less than 75% and in the absence of cleaning - 3.
When determining the value T(°C) the ambient air temperature should be taken T V(°C), equal to the average maximum temperature of the outside air of the hottest month of the year according to SNiP 2.01.01-82, and the temperature of the gas-air mixture emitted into the atmosphere T G(°C) - according to the technological standards in force for this production. For boiler houses operating according to the heating schedule, it is allowed to take the following values in calculations: T V equal to the average outside air temperatures for the coldest month according to SNiP 2.01.01-82.
Dimensionless coefficient value F accepted:
a) for gaseous harmful substances and fine aerosols (dust, ash, etc., the rate of ordered sedimentation of which is practically zero) - 1;
b) for fine aerosols with an average operational emission purification factor of at least 90% - 2; from 75 to 90% - 2.5; less than 75% and in the absence of cleaning - 3.
Coefficient values m And n determined by nomograms or calculated.
All sources of emissions are divided into 2 types: organized and unorganized. Organized sources of emissions include:
— smoke and ventilation pipes (pipe from the boiler, pipe from the metalworking shop, pipe from the welding station, pipe from the diesel power plant);
— ventilation shafts (air ducts in coal mines);
— an aeration lantern is an air duct system designed to exhaust polluted air. It is a group of exhaust hoods that form a dome on the roof of a building. Aeration lamps are used in large enterprises;
— deflectors are a device that is installed on the pipe to increase the exhaust speed.
Fugitive sources of emissions include:
— leaks of technological equipment (shut-off and control valves, joints of pumping equipment);
— flare installations (discharge candle, sour flare);
— open storage of fuel and materials (oil trap, fuel and lubricants warehouse);
- imploding works;
— reloading of dust-producing materials (unloading crushed stone from KamAZ, excavation work);
— technological processes performed outdoors (painting work, welding work, vehicle operation, vehicle passage, waterproofing work).
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Life safety in the technosphere / Sources of environmental pollution / 6. Study of sources of air pollution
Sources of air pollution are classified as follows:
— stationary (industrial enterprises and municipal boiler houses);
— non-stationary or mobile (transport).
When studying stationary sources of air pollution, two groups of sources are distinguished: sources of emission and sources of emissions of harmful substances.
Selection source- this is a technological unit (installation, device, apparatus, production line, etc.) or another object (burning rock dump) that emits harmful substances during operation (Fig. 6.1).
Emission source- this is a technical system or device (pipe, various ventilation devices) through which the release of harmful substances into the space surrounding the enterprise is organized (Fig. 6.1). a release organized in this way is called gas-air mixture - DHW.
Using such devices, changing their parameters (height, diameter, DHW speed) or installing together with them wastewater treatment plants, you can influence the amount of emissions, and therefore the degree of environmental pollution.
From the point of view of organizing emissions, it is customary to divide all sources of emissions of harmful substances into:
- organized - pipe, deflector or any other outlet device of the ventilation system;
- unorganized - dusty territory; any installation located outdoors.
Organized sources of emissions of harmful substances have special systems for discharging emissions into the environment. Unorganized - they do not have such systems and emit harmful substances directly into the atmospheric air.
There are main characteristics of organized emission sources:
1. source height H, m;
2. hole diameter D, m;
3. DHW consumption W, m3/s;
4. DHW temperature T, oC.
Using calculations using special techniques, the emission parameters are determined:
1. emission power m, g/s;
2. gross emission M, t/year.
Main characteristics of fugitive emission sources:
1. linear dimensions – coordinates along the X, Y and Z axes, m (Fig. 6.2);
2. surface area S, m2.
The emission power and gross emission are also calculated using special methods.
Analysis of sources of air pollution by calculation methods is carried out in two stages.
I. The first stage is called inventory of pollution sources. The objects of the study are legal entities - enterprises, organizations. The output characteristics of this stage of research for organizational sources are:
1) Release parameters: emission power G (g/s) and gross emission M (t/g). Calculations of emission power and gross emission are based on the use of specific emission values mij per unit of travel (g/km), per unit of time of a given process (g/min), per unit of raw materials consumed (g/kg). This method of determining gross emission and emission power is called balance calculation method.
The emission parameters can also be determined metrologically (methods of instrumental measurements). The measured quantities are:
— concentration of the i-th substance at the mouth of the emission source C (mg/m3);
— volumetric flow rate of domestic hot water (volume) V (m3/s).
2) Output characteristics for fugitive sources are: gross emission, emission power, dimensions of the site from which the emission is made, and coordinates.
The set of output characteristics of the research object obtained during the inventory is called calculation model.
The process of transition from a real object of study to its description using a set of parameters is called modeling.
The main purpose of inventory of pollutant emissions is to obtain initial data to solve the following problems:
assessing the degree of impact of pollutant emissions on the environment (atmospheric air);
2. development of draft standards for maximum permissible emissions of pollutants into the atmosphere both in general from enterprises and for individual sources of air pollution;
3. organizing control over compliance with established standards for emissions of pollutants into the atmosphere;
4. assessment of the environmental characteristics of technologies used at the enterprise;
5. planning air protection work at the enterprise.
When conducting an inventory of pollutant emissions, Inventory Forms are filled out. Appendix 2 contains Inventory Forms for one of the divisions railway– Distance of civil structures of the Far Eastern Railway. As an example, two sites are considered: Novy Urgal station and Urgal-1. Sources of environmental pollution are: boiler room, coal warehouse, welding, slag site, garage, woodworking shop, fuel and lubricants warehouse. The tables show which harmful substances and their gross emissions are released into the atmosphere.
II. Second level - development of draft standards for maximum permissible emissions (MPE). Here, the output characteristics are the C concentration fields (mg/m3 or in fractions of the MPC) in the active pollution zone (APZ) in the area around the source under study. The value of concentration C is determined on the basis of Professor Berlandt’s mathematical model, implemented in the form of regulatory documents (OND-86 and OND-90) and application packages “Ecologist”, “Prism” and other approved programs.
primary goal this stage research:
1. establishing standards for maximum permissible and temporarily agreed upon emissions;
2. determination of special operating modes under adverse weather conditions (NMU);
3. determination of the size and boundaries of the sanitary protection zone (SPZ);
4. consideration of the development prospects of the enterprise;
5. analysis of all possible accidents and emergencies regarding the current situation and development prospects.
Calculation of gross and maximum one-time emissions of pollutants is carried out using specific indicators, i.e. the amount of emitted pollutants, reduced to units of time and equipment, mass of consumable materials.
Specific indicators for the release of pollutants from technological sources are given based on the results of research and observations provided by various research and design institutes.
The enterprise carries out work on calculating emissions of pollutants either on its own or engages for this purpose a specialized organization that has a license to carry out such work. If calculations of pollutant emissions are carried out by a specialized organization, then it must require from the enterprise initial data on the actual quantity and type of equipment, quantity and brands of materials consumed, the number of operating days per year for each piece of equipment and its net operating time per day. The enterprise is responsible for the completeness and accuracy of inventory data.
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Classification of pollutant emission sources.
Air pollution - changes in the composition of the atmosphere as a result of impurities entering it.
Emission sources into the atmosphere are divided into natural, caused by natural processes , and anthropogenic (technogenic), resulting from human activity .
Natural sources of air pollution include dust storms, tracts of greenery during the flowering period, steppe and forest fires, and volcanic eruptions. Impurities emitted from natural sources:
1. dust of plant, volcanic, cosmic origin, soil erosion products, sea salt particles; fogs, smoke and gases from forest and steppe fires; gases of volcanic origin; products of plant, animal, bacterial origin.
2. Natural sources are usually areal (distributed) and act for a relatively short time. The level of atmospheric pollution from natural sources is background and changes little over time.
Anthropogenic (technogenic) sources of air pollution, represented mainly by emissions from industrial enterprises and vehicles, are distinguished by their large number and variety of types (Fig. 4.3).
Rice. 4.3. Sources of air pollution:
1 - high chimney; 2 - low chimney; 3 - workshop aeration lantern; 4 - evaporation from the surface of the pool; 5 - leaks through equipment leaks; 6 - dusting during unloading of bulk materials; 7 - car exhaust pipe; 8 - direction of air flow.
Sources of emissions from industrial enterprises are stationary(sources 1-6), when the coordinate of the emission source does not change over time, and mobile (non-stationary)(source 7 - motor transport).
Sources of emissions into the atmosphere are divided into: point, linear and area.
Each of them can be shaded and unshaded*
Point sources(in Fig. 4.3 - 1, 2, 5, 7) - these are pollution concentrated in one place. These include chimneys, ventilation shafts, and roof fans.
Line sources(3) have a significant extent. These are aeration lamps, rows open windows, closely spaced roof fans. These may also include highways.
Area Sources(4, 6). Here, the removed contaminants are dispersed along the plane of the industrial site of the enterprise. Area sources include storage areas for industrial and household waste, parking lots, and warehouses for fuel and lubricants.
Unshaded(1), or high, sources are located in the undeformed wind flow. These are chimneys and other sources that emit pollution to a height exceeding 2.5 times the height of nearby buildings and other obstacles.
Shadowed sources(2-7) are located in the area of support or aerodynamic shadow of a building or other obstacle.
Sources of emissions of pollutants into the atmosphere are divided into organized and unorganized.
From an organized source(1, 2, 7) pollutants enter the atmosphere through specially constructed flues, air ducts and pipes.
Unorganized source release of pollutants (5, 6) is formed as a result of a violation of the tightness of the equipment, the absence or unsatisfactory operation of equipment for the suction of dust and gases in places where the product is loaded, unloaded or stored. Unorganized sources include parking lots, warehouses for fuel and lubricants or bulk materials, and other area sources.
Article 13. Classification of emission sources
Emission sources are classified into stationary, mobile and non-stationary.
TO organizedstationary sources emissions include emission sources equipped with devices through which the entry of pollutants into the atmospheric air from sources of pollutant release is localized.
TO unorganizedstationary sources emissions include emission sources that are not equipped with devices through which the entry of pollutants into the atmospheric air from sources of emission of pollutants is localized.
5. Mobile sources emissions are divided into:
5.1. power-driven vehicles (except for those driven by electric motors);
5.2. railway vehicles (except for those driven by electric motors);
5.3. aircraft;
5.4. sea vessels, inland navigation vessels, mixed (river-sea) navigation vessels, small vessels;
5.5. self-propelled vehicles.
Towards non-stationary emission sources These include emission sources that are not stationary or mobile emission sources and are included in the list of non-stationary emission sources approved by the Ministry of Natural Resources and Environmental Protection of the Republic of Belarus.
CHAPTER 5
REQUIREMENTS FOR AIR PROTECTION
Article 21. Responsibilities of legal entities, citizens, including individual entrepreneurs, carrying out economic and other activities related to emissions of pollutants into the air
1. Legal entities and individual entrepreneurs carrying out economic and other activities related to emissions of pollutants into the air are obliged to:
1.1. comply with the requirements established by this Law and other acts of legislation on the protection of atmospheric air, on environmental protection, including the mandatory requirements of technical regulatory legal acts;
1.2. develop and implement measures aimed at preventing air pollution, including during accidents;
1.3. not to allow the established standards in the field of atmospheric air protection to be exceeded, and if such standards are exceeded, take measures to eliminate the causes and consequences of excess emissions of pollutants into the air and immediately inform the territorial bodies of the Ministry of Natural Resources and Environmental Protection of the Republic of Belarus about such facts from the moment their detection, and in case of threatening situations emergency– bodies and divisions of the Ministry of emergency situations The Republic of Belarus;
1.4. suspend until identified violations are eliminated or completely stop the operation of emission sources if it is impossible to comply with standards in the field of atmospheric air protection;
1.5. develop measures to reduce emissions of pollutants into the air during periods of unfavorable meteorological conditions and ensure their implementation;
1.6. provide environmental information in accordance with environmental legislation;
1.7. carry out production control in the field of atmospheric air protection;
1.8. provide training (training), instruction, knowledge testing, and advanced training for workers involved in atmospheric air protection.
2. Legal entities, individual entrepreneurs carrying out economic and other activities related to emissions of pollutants into the air from stationary emission sources, in addition to the responsibilities specified in the HYPERLINK paragraph "http://pravo.by/webnpa/text.asp?RN =H10800002"1 of this article, are obliged to:
2.1. develop draft standards for permissible emissions of pollutants into the air;
2.2. obtain permission to emit pollutants into the air and comply with its conditions;
2.3. equip organized stationary sources of emissions with gas cleaning installations in cases provided for paragraph 1 Article 27 of this Law;
2.4. operate gas treatment plants in technically sound condition in accordance with the rules for operating gas treatment plants approved by the Ministry of Natural Resources and Environmental Protection of the Republic of Belarus;
keep records in the field of atmospheric air protection;
2.6. carry out an inventory of emissions of pollutants into the atmospheric air;
2.7. carry out analytical (laboratory) control of the quantitative and qualitative composition of emissions of pollutants into the atmospheric air and the quality of atmospheric air in the affected area in cases provided for by acts of legislation on environmental protection, including mandatory requirements for compliance with technical regulatory legal acts;
2.8. equip organized stationary sources of emissions with automated systems for monitoring emissions of pollutants into the atmospheric air in cases provided for by the mandatory requirements of technical regulatory legal acts;
2.9. carry out, independently or with the involvement of accredited laboratories with the appropriate scope of accreditation, local environmental monitoring, the object of observation of which is emissions of pollutants into the air, in cases provided for by acts of legislation on environmental protection, including mandatory requirements for compliance with technical regulatory legal acts.
3. Legal entities and individual entrepreneurs engaged in the production of engines with which mobile emission sources are equipped, as well as mobile emission sources, are required to establish technological standards for emissions of pollutants into the air in accordance with the mandatory requirements of technical regulatory legal acts, obligations under international treaties of the Republic of Belarus .
4. Legal entities and individual entrepreneurs operating mobile emission sources, in addition to the responsibilities specified in paragraph HYPERLINK "http://pravo.by/webnpa/text.asp?RN=H10800002"1 of this article, are obliged to:
4.1. comply with the operating rules for systems for neutralizing pollutants contained in the exhaust gases of mobile emission sources, established by the manufacturer of these systems;
4.2. ensure compliance with the standards for the content of pollutants in the exhaust gases of mobile emission sources established in accordance with clause HYPERLINK "http://pravo.by/webnpa/text.asp?RN=H10800002"6 of Article 18 of this Law.
5. Citizens operating motor vehicles are required to ensure compliance with the standards for the content of pollutants in the exhaust gases of mobile emission sources established in accordance with the HYPERLINK clause "http://pravo.by/webnpa/text.asp?RN=H10800002"6 Article 18 of this Law.
Article 33. Permit for emissions of pollutants into the air
1. Operation of stationary emission sources legal entities, individual entrepreneurs, carrying out economic and other activities related to emissions of pollutants into the air, is permitted only if there is a permit for emissions of pollutants into the air, issued by the Ministry of Natural Resources and Environmental Protection of the Republic of Belarus or its territorial bodies.
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The air environment is subject to massive pollution by harmful substances. Objects from which pollutants enter the atmosphere are called sources of pollution (emissions). They can be natural or anthropogenic. Natural sources of pollution are volcanic eruptions, dust storms, forest fires, etc. The level of atmospheric pollution from these sources is background and changes little over time. Anthropogenic pollution is characterized by a variety of types and numerous sources.
All anthropogenic sources of pollution are divided into point, linear and area. Point sources can be stationary or mobile.
TO stationary point sources include chimneys of power plants, boiler houses, technological installations, furnaces, ventilation pipes of enterprises, etc.
Mobile emission sources are mechanical and railway vehicles (except for those driven
driven by electric motors), aircraft and sea vessels, inland navigation vessels and other mobile vehicles.
Line sources air pollution consists of roads and streets along which transport systematically moves, as well as open technological lines of enterprises, etc.
TO area sources These include ventilation lights, windows, doors, leaks in equipment, buildings through which impurities can enter the atmosphere, storage areas for bulk materials, rock dumps, waste storage facilities, etc.
Sources of pollutant emissions are divided into organized and unorganized.
TO organized stationary sources of emissions regarding
there are emission sources equipped with devices through which the influx of pollutants is localized
into the atmospheric air from sources of emission of pollutants. For example, pipes, ventilation windows, etc.
Unorganized stationary sources of emissions–source-
emission centers that are not equipped with devices through which the entry of pollutants into the atmospheric air from sources of pollutant emission is localized.
Unorganized stationary sources of emissions include
linear, if pollutants enter the atmospheric air from gas pipelines;
areal, if pollutants enter the atmospheric air from dispersed sources of pollutant release, including from treatment facilities Wastewater, storage areas for bulk materials, mining dumps, waste disposal facilities, waste storage facilities, objects of gravity for mobile emission sources.
THE MOST COMMON ATMOSPHERE POLLUTANTS
The problem of air pollution became especially acute in the second half of the twentieth century due to the extremely high growth rates of industrial production, generation and consumption of electricity, production and use of a large number of vehicles.
With the advent of internal combustion engines, large thermal power plants, further development industry annually releases more than 20 billion tons of carbon dioxide, 250 million tons of dust, 200 million tons of carbon monoxide, 150 million tons of sulfur dioxide, 50 million tons of nitrogen oxides, 50 million tons of various hydrocarbons into the air basin.
Thus, the most common air pollutants are:
carbon monoxide;
sulfur dioxide;
nitrogen oxides NO x ; hydrocarbons C n H m ;
solid particles (dust) of organic and inorganic matter
origins.
Approximate relative composition of pollutants in the atmosphere of industrial cities: CO – 45%, SO 2 – 18%, C n H m – 15%,
dust – 12%, NO x – 10%.
Carbon monoxide (CO)– a colorless gas, odorless and tasteless. Acting on the nervous and cardiovascular systems, CO causes suffocation. Primary symptoms of poisoning (headache) occur at concentrations of 200–220 mg/m3 and duration of exposure for 2–3 hours. As concentration increases, a sensation of pulse in the temples and dizziness appear.
Sulfur dioxide (SO 2)– a colorless gas with a pungent odor. Its presence creates an unpleasant taste in the mouth already at concentrations of 3 – 6 mg/m3. At concentrations of 20 – 30 mg/m3, it is irritating to the mucous membrane of the eyes and respiratory tract. At concentrations of approximately 50 mg/m 3 it forms compounds with moisture H 2 SO 3 and H 2 SO 4. In nature, coniferous and deciduous forests are most sensitive to SO 2, since
this substance accumulates in leaves and needles. At high concentrations of SO 2, pine dries out.
Nitrogen oxides NO x (NO, N 2 O, NO 2, N 2 O 3, N 2 O 5) have no color or odor, are poisonous, irritate the respiratory system. The most dangerous are NO And NO 2. Inhaling toxic nitrogen dioxide fumes can cause serious poisoning. In contact with water, NO x forms acids HNO 3 and HNO 2, which create edema in the lungs. Nitrogen oxides are especially dangerous in cities, where they, interacting with hydrocarbons from vehicle exhaust gases, form photochemical fog - “smog”.
Particulate matter(dust, suspended substances) -this is small-
small particles of solid matter suspended in the air. The presence of dust in the air leads to a decrease in the transparency of the atmosphere and increased scattering of sunlight. In addition, dust particles are nuclei of condensation of water vapor, and also have an adsorption capacity for toxic substances. The degree of harmful effects of dust on the human body depends on the amount of inhaled dust, its chemical composition, the degree of dispersion of dust particles, their shape, hardness, electrical charge, solubility in water and biological media.
Particles with a diameter of more than 10 microns do not enter the respiratory tract and have no impact on health. Therefore, the aerodynamic diameter of dust particles of 10 μm or less is usually considered as a threshold. It is these particles that enter the bronchi or lungs and thereby affect health and mortality. The most dangerous are fine solid particles less than 2.5 microns in size.
Many hydrocarbons C n H m are toxic substances, and such as benzene, polycyclic aromatic hydrocarbons (benz(a)pyrene), dioxins, polychlorinated biphenyls and others are carcinogenic.
In addition to those mentioned above, other harmful substances are also released into the atmosphere. In total, about 7 million chemical compounds are currently known. Of these, approximately 3 million are used in practice, 40 thousand have harmful properties and 12 thousand are toxic.
Depending on the degree of harmfulness when exposed to the human body, substances are divided into 4 hazard classes:
1) extremely dangerous (heavy metals (mercury, lead, cadmium, vanadium, nickel, chromium) and their compounds, etc.);
2) highly hazardous (nitrogen dioxide, aerosols of sulfuric and hydrochloric acids, formaldehyde, hydrogen fluoride, hydrogen sulfide, chlorine, etc.);
3) moderately hazardous (sulfur dioxide, caprolactam, phenol, xylene, acetic acid, etc.);
4) low-hazard (carbon monoxide, acetone, ethyl acetate, turpentine, ethyl alcohol, etc.).
AIR POLLUTION
IN REPUBLIC OF BELARUS
Ambient air pollution is actual problem for cities of Belarus. The main sources of emissions of pollutants into the atmosphere are motor vehicles, energy facilities and industrial enterprises. Gross emissions from stationary and mobile sources in 2008 on the territory of Belarus amounted to 1596.6 thousand tons (75.2% from mobile sources, 24.8% from stationary sources) (Table 8.1).
Table 8.1 – Gross emissions of pollutants into the atmosphere from stationary and mobile sources on the territory of Belarus in
2008, thousand tons
| Region | Solids | Carbon oxide | Sulfur dioxide | Nitrogen oxides | Carbohydrates | Others | Total | |
| Brest | 11,7 | 128,4 | 2,2 | 23,6 | 41,1 | 0,7 | 208,2 | |
| Vitebsk | 13,2 | 112,3 | 25,4 | 31,8 | 66,9 | 3,6 | 253,2 | |
| Gomel | 11,8 | 126,6 | 22,5 | 28,4 | 57,0 | 5,5 | 251,9 | |
| Grodno | 11,9 | 115,3 | 1,2 | 23,2 | 38,3 | 5,5 | 195,4 | |
| Minsk | 173,2 | 7,2 | 29,5 | 52,8 | 4,1 | 283,8 | ||
| Minsk | 9,3 | 158,9 | 5,0 | 24,2 | 49,2 | 0,8 | 247,4 | |
| Mogilevskaya | 10,8 | 88,9 | 2,0 | 17,1 | 35,5 | 2,4 | 156,7 | |
| Republic | 85,7 | 903,6 | 65,2 | 177,8 | 341,1 | 22,8 | 1596,6 | |
| Belarus | ||||||||
The total volume of emissions from stationary sources amounted to 396.1 thousand tons, including 278.2 thousand tons from technological, production and other processes. Gross emissions from mobile sources amounted to 1200.6 thousand tons.
About 70% of the total emissions of pollutants into the atmosphere from stationary sources comes from industry. The largest amount of emissions is typical for the fuel industry (32%) and electric power industry (21%).
Carbon monoxide predominates in the composition of gross emissions of pollutants (56.6%). Hydrocarbons account for 21.4%, nitrogen oxides – 11.1%, solids – 5.4%, sulfur dioxide – 4.1%. Most of the carbon monoxide (90.2%), hydrocarbons (67.2%), and nitrogen oxides (65.5%) released into the atmosphere is due to the operation of mobile sources. 97.6% of sulfur dioxide and 55.4% of solid substances entered the atmosphere from stationary emission sources.
The distribution of emissions across the territory of Belarus is uneven. In terms of the amount of pollutant emissions into the atmosphere from stationary sources, Novopolotsk (79.8 thousand tons) and Minsk (34.6 thousand tons) stand out.
To compare emissions at the regional level and between different countries, various indicators of the existing burden on the environment and people are currently used. The most indicative of them are considered to be data on the annual volumes of emissions into the atmospheric air, both in general and for the main pollutants, expressed per unit area and per capita.
In general, for Belarus, the emission indicator calculated per unit area was 7.69 t/km2, varying within the country from 5.4 t/km2 (Mogilev region) to 13.2 t/km2 (Minsk region) .
Emission indicators for the main pollutants calculated for the country as a whole are presented in Table 8.2.
Table 8.2 – Indicators of emissions of pollutants into the atmosphere from stationary and mobile sources on the territory of Belarus in 2008
The maximum values both per unit area and per capita are characteristic of carbon monoxide.
In per capita terms, the emission rate was 0.16 t/person. At the regional level, the highest value of this indicator was established for the Vitebsk region (0.2 t/person), the lowest - for the Mogilev region (0.14 t/person).
Anthropogenic pollution is pollution caused by human activities.
In turn, sources of anthropogenic pollution are stationary And mobile. Mobile sources of pollution include all types of transport (with the exception of pipelines).
According to their geometric characteristics, stationary sources of pollution can be point,linear And areal.
Point source of pollution- this is a source that emits air pollutants from an installed opening (chimneys, ventilation hoods).
Linear source of pollution- this is a source that emits air pollutants along an established line (window openings, rows of deflectors, loading racks).
Area source of pollution- this is a source that emits air pollutants from an installed surface (tank farms, open evaporation surfaces, storage and transfer areas for bulk materials, etc.).
Stationary source of pollution- is an enterprise, workshop, unit, installation or other stationary object, which maintains its spatial coordinates for a certain time and releases pollutants into the atmosphere and/or discharges pollutants into water bodies.
Sources of air pollution are stationary (industrial enterprises and municipal boiler houses) and mobile (transport). There are two groups of stationary sources of pollution: sources of release and sources of emissions of harmful substances.
Sources of air pollution in rural areas. In rural areas, the main air pollutants are livestock and poultry farms, industrial complexes for the production of meat, enterprises district association"Agricultural equipment", energy and thermal power enterprises, pesticides used in agriculture. In the area where premises for keeping livestock and poultry are located, ammonia, hydrogen sulfide and other foul-smelling gases can enter the atmosphere and spread over considerable distances.
Sources of air pollution include warehouses where seeds are treated with pesticides, fields where pesticides and mineral fertilizers are applied in one form or another, as well as cotton gins. When cotton seeds are treated with granosan and mercuzan, air pollution can be traced over a considerable distance.
As a result of draining and loading operations, as well as daily temperature fluctuations, a fairly intense release of evaporation products into the surface layer of the atmosphere occurs.
Dangerous air pollution at gas and gas production facilities oil industry occur, on the one hand, as a result of emissions of harmful substances from various sources, on the other hand, as a result of the formation of secondary products of chemical transformation formed during the interaction of pollutants with air components, solid and liquid substances contained in it, some pollutants with others, etc. In many cases, the environmental and sanitary hazards of secondary pollutants are significantly higher than harmful emissions. Meanwhile, the composition, structure and properties of these daughter substances for production facilities in the gas and oil industries have not previously been comprehensively studied. The authors have attempted to partially fill the gap that has arisen here.
Often the air contains harmful substances, the presence of which is not caused by the activities of the polluting enterprise in question, but is a consequence of air pollution from other, often very distant sources.
Another source of environmental pollution are greases. Depending on storage and application conditions, losses of greases reach 30-40% of their total consumption. For example, when storing and filling solid oil, losses in the form of residues on the walls of the container are 0.9% from sticking to the spatula and test injections when using a manual syringe 7.6%, removal of air from the syringe 7.8%, residues on grease nipples 3 .1%, on injection parts 0.2%, etc.
Natural sources of pollution, as a rule, are dispersed in space, remote from densely populated areas and practically impossible to regulate. At the same time, the harmful effects of air pollutants entering the environment from natural sources are largely neutralized by their mixing, dispersion and natural process self-purification of the atmosphere.
The main sources of air pollution are industrial enterprises, thermal power plants And power plants, various heating boilers, where both gaseous and liquid hydrocarbons are used as fuel. It should be noted that if the combustion of gaseous fuels is characterized by more or less economic and environmental indicators, then the combustion of fuel oil is accompanied by the release into the atmosphere of a significant volume of incomplete combustion products - oxides of nitrogen, sulfur and carbon.
The main sources of air pollution in industrialized countries are cars and other types of transport, industrial enterprises, and thermal power plants. Every year, 200-250 million tons of ash and up to 60 million tons of sulfur dioxide are released into the atmosphere. In the USA, as a result of the combustion of coal and oil at thermal power plants, 74% of all sulfuric acid oxides entering the atmosphere and about half of nitrogen oxides are released into the country's air basin.
Reactions to air pollution can be acute or chronic, and the nature of the impact can be local or general, toxic, irritating, cumulative. In general, long-term exposures at low concentrations are considered more dangerous than short-term exposures at high concentrations. It is noted that the damaging factor can be either a simple sum of the corresponding effects of individual pollutants or exceed this value (synergistic effect). For example, lung diseases are much more common if the atmosphere is polluted by sulfur dioxide combined with dust emissions. There is numerous data on the connection between pulmonary, oncological, skin and other pathologies with the nature and level of air pollution. The frequency of diseases is proportional to the number of sources of pollution and depends on their composition, structure, chemical properties and a number of other factors.
The main sources of pollution of the surface layer of the atmosphere during pipeline transport of oil, petroleum products and gas include emergency gas emissions during failures and repairs of the linear part of main gas pipelines and the evaporation of oil and petroleum products during storage in tanks. An equally strong source of air pollution are fires when transported products are ignited or burned.
When analyzing air production premises, which contains more complex compositions of pollutants than in the atmosphere, air sampling has its own characteristics. To capture toxic impurities from the air in quantities sufficient for subsequent determination, select the most suitable effective conditions its absorption from the air, based on physical and chemical properties analyte and its concentration. If sampling of any individual substance requires a rational choice of absorption medium and optimal air suction rate, then in the case of more complex system When the air is contaminated with a mixture of toxic substances, it is necessary to take into account the possible interactions of the components of the analyzed mixture of substances. The nature of the source of emission of harmful impurities is also important - instantaneous or continuously operating, with constant or varying productivity.
The sources of possible release of pollutants into the atmosphere, water bodies and soil from production facilities of the oil and gas industry are considered. The volumes, composition, structure and properties of pollutants are given, and their environmental hazard is assessed. The specific contribution of various industries to environmental pollution and the possible consequences of pollution have been determined, taking into account the chemical transformations of harmful substances in air and water and the formation of toxic products. A set of means and methods for preventing environmental pollution is recommended.
When calculating air pollution from sources of rectangular cross-section, it is advisable to use regulatory documents.
A significant source of atmospheric air pollution with dust is the so-called “tailings” of enrichment factories. Waste heaps worsen the landscape and take away agricultural land. Processing the dumps will make it possible to extract coal and raw materials from them for the production of cement and ceramics. The rock can serve as a building material. The remaining recycled waste should be used to fill mined-out mines instead of sand. The development of mineral resources should be carried out in such a way as to make the most complete use of all their constituent elements, not to throw even low-grade ores into the dump, to completely exhaust deposits, and to preserve minerals during transportation to processing sites. After the development of mineral resources, it is necessary to restore the landscape. These works must be organized very carefully: it is necessary to protect the fertile layer of soil and backfill the resulting voids.
Sinter plants are a significant source of air pollution with sulfur dioxide. During ore agglomeration, sulfur burns out from pyrites. Sulfide ores contain up to 10% sulfur, and after agglomeration only 0.2-0.8% remains. The emission of sulfur dioxide during sintering can be taken at the rate of 190 kg per 1 ton of ore, i.e. one belt machine produces about 700 tons of sulfur dioxide per day.[
The largest source of air pollution from hydrocarbons are tanks for oil and petroleum products. Hydrocarbons enter the atmosphere through special breathing valves, hatches, leaks, and when filling tanks.
In terms of chemical pollution of the air basin, Ufa is characterized as one of the most polluted cities in Russia. According to statistics from 2TP-Air, emissions of harmful substances throughout the city in 1999 amounted to 486.2 thousand tons per year, of which 218.4 thousand tons came from stationary sources and 268.2 thousand tons from vehicles. The share of motor vehicles in gross emissions is 55%.
Atmospheric pollution is a change in the composition of the atmosphere as a result of impurities entering it.
An atmospheric impurity is a substance dispersed in the atmosphere that is not contained in its permanent composition.
An air pollutant is a contaminant in the atmosphere that has adverse effects on the environment and public health.
Since impurities in the atmosphere can undergo various transformations, they can be divided into primary and secondary.
A primary impurity in the atmosphere is an impurity that has retained its physical and chemical properties over the time interval under consideration.
Transformation of impurities in the atmosphere is a process in which impurities in the atmosphere undergo physical and chemical changes under the influence of natural and anthropogenic factors, as well as as a result of interaction with each other.
A secondary impurity in the atmosphere is an impurity in the atmosphere formed as a result of the transformation of primary impurities.
Based on their effects on the human body, air pollution is divided into physical and chemical. Physical include: radioactive radiation, thermal effects, noise, low-frequency vibrations, electromagnetic fields. To chemical - availability chemical substances and their connections.
Emissions of pollutants into the atmosphere are characterized by 4 characteristics: state of aggregation, chemical composition, particle size and mass flow rate of the emitted substance.
Pollutants are released into the atmosphere in the form of a mixture of dust, smoke, fog, steam and gases.
Sources of emissions into the atmosphere are divided into natural, caused by natural processes, and anthropogenic (technogenic), which are the result of human activity.
Natural sources of air pollution include dust storms, tracts of greenery during the flowering period, steppe and forest fires, and volcanic eruptions.
Impurities released from natural sources:
- dust of plant, volcanic, cosmic origin, soil erosion products, sea salt particles; fogs, smoke and gases from forest and steppe fires; gases of volcanic origin; products of plant, animal, bacterial origin.
- Natural sources are usually area-based (distributed) and act for a relatively short time. The level of atmospheric pollution from natural sources is background and changes little over time.
Anthropogenic (technogenic) sources of air pollution, represented mainly by emissions from industrial enterprises and vehicles, are distinguished by their large number and variety of types (Fig. 4.3).
Rice. 4.3. Sources of air pollution:
1 - high chimney; 2 - low chimney; 3 - workshop aeration lantern; 4 - evaporation from the surface of the pool; 5 - leaks through equipment leaks; 6 - dusting during unloading of bulk materials; 7 - car exhaust pipe; 8 - direction of air flow
Sources of emissions from industrial enterprises can be stationary (sources 1-6), when the coordinate of the emission source does not change over time, and mobile (non-stationary) (source 7 - motor transport).
Sources of emissions into the atmosphere are divided into: point, linear and area.
Each of them can be shaded or unshaded*
Point sources (in Fig. 4.3 - 1, 2, 5, 7) are pollution concentrated in one place. These include chimneys, ventilation shafts, and roof fans.
Linear sources (3) have a significant length. These are aeration lights, rows of open windows, and closely spaced roof fans. These may also include highways.
Area Sources (4, 6). Here, the removed contaminants are dispersed along the plane of the industrial site of the enterprise. Area sources include storage areas for industrial and household waste, parking lots, and warehouses for fuel and lubricants.
Unshaded (1), or high, sources are located in an undeformed wind flow. These are chimneys and other sources that emit pollution to a height exceeding 2.5 times the height of nearby buildings and other obstacles.
Shadowed sources (2-7) are located in the zone of backwater or aerodynamic shadow of a building or other obstacle.
Sources of emissions of pollutants into the atmosphere are divided into organized and unorganized.
From an organized source. (1, 2, 7) pollutants enter the atmosphere through specially constructed flues, air ducts and pipes.
An unorganized source of emission of pollutants (5, 6) is formed as a result of a violation of the tightness of the equipment, the absence or unsatisfactory operation of equipment for the suction of dust and gases in places where the product is loaded, unloaded or stored. Unorganized sources include parking lots, warehouses for fuel and lubricants or bulk materials, and other area sources.
The most common pollutants entering the atmospheric air from technogenic sources are: carbon monoxide CO; sulfur dioxide S02; nitrogen oxides NOx; hydrocarbons CH; dust.
Carbon monoxide (CO) is the most common and most significant atmospheric impurity, commonly called carbon monoxide. The CO content in natural conditions is from 0.01 to 0.2 mg/m3. The bulk of CO emissions are generated during the combustion of fossil fuels, primarily in internal combustion engines. CO content in the air major cities fluctuates between 1-250 mg/m3, with an average value of 20 mg/m3. The highest concentration of CO is observed on streets and squares of cities with heavy traffic, especially at intersections. A high concentration of CO in the air leads to physiological changes in the human body, and a concentration of more than 750 mg/m3 leads to death. CO is an extremely aggressive gas that easily combines with hemoglobin in the blood, forming carboxyhemoglobin. The state of the body when breathing air containing carbon monoxide is characterized by the data given in table. 4.2. ?
Table 4.2. Effect of carbon monoxide on the human body
The degree of exposure to CO on the human body also depends on the duration of exposure (exposure) and the type of human activity. For example, when the CO content in the air is 10-50 mg/m3, which is observed at the intersections of streets in large cities, with an exposure of ~ 60 minutes the violations given in paragraph 1 are noted, and with exposure from 12 hours to 6 weeks - in paragraph 2 . During heavy physical work, poisoning occurs 2-3 times faster. The formation of carboxyhemoglobin is a reversible process; after 3-4 hours its content in the blood decreases by 2 times. The residence time of CO in the atmosphere is 2-4 months.
Sulfur dioxide (S02) is a colorless gas with a pungent odor. It accounts for up to 95% of the total volume of sulfur compounds entering the atmosphere from anthropogenic sources. Up to 70% of S02 emissions are generated by burning coal, fuel oil - about 15%.
When the concentration of sulfur dioxide is 20-30 mg/m3, the mucous membrane of the mouth and eyes is irritated, and an unpleasant taste appears in the mouth. Coniferous forests are very sensitive to S02. When the S02 concentration in the air is 0.23-0.32 mg/m3, as a result of impaired photosynthesis, the needles dry out within 2-3 years. Similar changes in deciduous trees occur at S02 concentrations of 0.5-1 mg/m3.
The main man-made source of hydrocarbon emissions (CmHn - gasoline vapors, methane, pentane, hexane) is motor transport. Its share is more than 50% of total emissions. Incomplete combustion of fuel also results in the release of cyclic hydrocarbons, which have carcinogenic properties. Particularly high levels of carcinogenic substances are contained in the soot emitted by diesel engines. From hydrocarbons to atmospheric air Methane is the most common, which is a consequence of its low reactivity. Hydrocarbons have a narcotic effect, causing headaches and dizziness. When inhaling gasoline vapors with a concentration of more than 600 m*/m3 for 8 hours, headaches, coughing, and discomfort in the throat occur.
Nitrogen oxides (NOx) are formed during combustion at high temperatures by oxidizing part of the nitrogen present in the atmospheric air. The general formula NOx usually means the sum of NO and N02. The main sources of NOx emissions: internal combustion engines, industrial boiler furnaces, furnaces.
N02 - gas yellow color, giving the air in cities a brownish tint. The toxic effect of NOx begins with a slight cough. As the concentration increases, the cough intensifies, headache begins, and vomiting occurs. When NOx comes into contact with water vapor, the acids HN03 and HN02 are formed on the surface of the mucous membrane, which can lead to pulmonary edema. The duration of NO2 presence in the atmosphere is about 3 days.
The size of dust grains ranges from hundredths to several tens of microns.
The average size of dust particles in atmospheric air is 7-8 microns. Dust has a harmful effect on humans, plants and animal world, absorbs solar radiation and thereby affects the thermal regime of the atmosphere and the earth's surface. Dust particles serve as condensation nuclei in the formation of clouds and fogs. Main sources of dust formation: production building materials, ferrous and non-ferrous metallurgy (iron oxides, particles of Al, Cu, Zn), motor transport, dusty and smoldering storage areas for household and industrial waste. The bulk of dust is washed out of the atmosphere by precipitation.
