AIR PROTECTION

AIR PROTECTION1

Among the problems: within the sphere protecting of our environment, the problem of protection of atmospheric air is very important for several reasons. First, atmospheric air is of paramount importance of for all life on Earth. Secondly, the high sensitivity of the atmosphere to anthropogenic(man-made) influences. Thirdly, high mobility of air masses with which harmful impurities (man-made influences) can be transferred.

PROBLEMS of PROTECTION of ATMOSPHERIC AIR

2SOURCES OF POLLUTION OF THE ATMOSPHERE

Natural (natural)

Artificial (anthropogenic)-Cosmic dust-Dust storms-Volcanic Eruptions and Ejections-Forest fires-Aeration-Decomposition of terrestrial organisms

-Industry-Transport-Power system-Heating of dwellings-Agriculture

3In past decades man-made factors of air pollution began to exceed on scales natural pollution. Nowadays anthropogenic pollution got a global character.

The basic (man-made) sources of pollution of atmosphere in the modern world are:1.Power engineering2.Motor and Air transport.3.Industry (especially black and nonferrous metallurgy, and petrochemicals).

The importance of those or other sources of air pollution in different territories varies depending on level of scientific and technical progress, level of an accomplishment of the occupied places and many other socio-economic factors

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Motor Transport

Because of technical imperfections and Cars internal-combustion engines inefficiency inherent in burning fossil fuels, their constructive imperfections, and maintenance defects, all combine to cause the release of more than 200 chemical compounds contained in the exhaust which enters the atmosphere.Each car annually excretes in air 800kg of carbon monoxide, 220 kg of hydrocarbons and 40 kg of nitrogen-oxides on the average. Besides exhaust gases contains lead dioxins and soot (carbon black). Now in our country and all over the world they (government & industry) try to pass to a new kind of automobile fuel with higher octave number that promotes decrease carbon monoxides content in exhaust gases. However nitrogen oxides and lead remain active components of emissions5Motor transport, as a source of air pollution has number of distinctive features (peculiarities):

1. First of all, the number of cars quickly increases so the general emission of harmful substances into atmosphere continuously (constantly) grows.2. Secondly, unlike the industrial sources of pollution the car is a moving source.3. Thirdly, automobile emissions spread at the level of man breathing, so in the conditions of city buildings its dispersion are complicated.

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Air transport

Air transport considerably pollutes the atmosphere. At launch a 4-motor jet plane excrete the same volume of poisonous gases, as 6800 cars.At flight at the distance 1000km one plane uses as much oxygen, as one person consumes within a year, and as a result emits corresponding quantity of carbon dioxide. At flight for 8 hours from America to Europe a jet liner consumes 35 tons of oxygen. The same quantity of oxygen during the same period of time (8 hours) is produced by 25 thousand hectares of trees. Planes flying very high emit nitrogen oxides directly in the bottom layers of the stratosphere where as a result of some reactions destruction of the ozone layer of atmosphere occurs. It is known that ozone layer like screen protects the earth from ultra-violet radiation of the sun. Not surprisingly that pollution of the atmosphere near airports is especially great.7

Thermal power stations

Thermal power stations are one of the most powerful sources of pollution of atmospheric air. During burning of oil, coal and black oil various firm particles containing carbon dioxide, oxides of sulfur, nitrogen, calcium and iron, sulfurous gas, arsenic, selenium, radioactive elements are emitted into the air.Large thermal power stations throw out a considerable quantity of ashes. Such emissions reach 1000-3000 tons a day. By some estimations, coal burning results in 1000-3000 tons of carcinogenic arsenic are annually thrown out.

8The Industrial Enterprises

Considerable pollution of atmospheric air occurs owing to industrial enterprises. The powerful centers of pollution are created by metallurgy, especially nonferrous metallurgy. The enterprises of nonferrous metallurgy emit arsenic, lead, dust, sulphuric gas, fluoric compounds, oxides of heavy metals and a number of other impurities. Sometimes pollutants are found far way from source of pollution (4-5km).Oil refining factories, the enterprises of chemical industry are sources of emissions especially harmful substances (hydrocarbons, for example). It is known that some of them (especially polycyclic aromatic hydrocarbons) posses cancerogenic effect9

Sources of emissions of the industrial enterprises:

1.Losses of initial raw materials;2.Losses of intermediate products;3.Losses of end-products;4.Emissions of collateral impurity to raw materials;5.Losses of the various reagents applied to processing of the basic raw materials.10The ways of pollutants emissions

1.Emission of tail gases (the gases formed in the final stage of manufacturing);2. mission of exhausts (vent lines serve for moving away the excess quantities of gas and pressure leveling in hermetic capacities)3. Emissions of aspiration systems.4. Emissions of ventilating systems5. Emissions with air (through aero-efficient lanterns, windows, doorways) 6. Unorganized emissions (at evaporations of technical liquids)

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Hygienic value of atmosphere pollution

Economic damage

Air pollution causes not only ecologic damage but economic damage too. It can be a considerable loss of fuel, production and other valuable components during emissions. Emissions often contain valuable products which are wasted when they exhausted into the atmosphere. In particular, it is known that money expenses from recycling and cleaning air pollutants often exceed the aggregate profit of the enterprise got from basic production. Emissions of pollutants are often aggressive and promote fast destruction of building designs, and also negatively impact flora and fauna. The dust clogs up pores of leaves, and complicates photosynthesis processes. Leaves turn yellow, are covered by stains so, growth of trees is slow, and they easily perish from diseases of plants. The green trees function as a filter is damaged by polluting particles and gaseous impurities attacking the leaves and trunks. The role of trees as a source of oxygen and photosynthesis is decreased and their wind-shelter action is weakened. Productivity of agricultural crops and efficiency of animal industries are lowered especially in suburban economy of large industrial centers.Some mosses and lichens, some fruit and coniferous trees are especially sensitive to harmful influences.The decrease in degree of the natural light exposure, caused by dust pollution also increases an economic damage as it is necessary to use artificial light sources more intensively.

12Influence on a microclimate of the occupied places

Influence on a sanitary-and-hygienic condition of the population

Just particles of air are kernels of moisture condensation. Therefore the more quantities of dust pollutants in air the more size and scale of fogs. The frequency and duration of fogs in large industrial cities increases from year to year. Fogs with long duration (evaporation time), promote deterioration of health and working capacity of the population, increase in number of street accidences, and generally oppress peoples state of health. Especially in elderly people or people with respiratory problems. Besides fogs lead to reduce of natural illumination (40-50%), causing extra expenses for street lights.Fogs can be light, intermediate, or heavy. Heavy fogs are most damaging. Furthermore, climatologists notice that in connection with increase in quantity of the weighed particles in air of cities skies overcast increases 5-10%.

Pollution of atmosphere decreases its transparency and reduces natural light which in own turn worsen sanitary living conditions of the population. Atmospheric pollution increases pollution of windows, dwellings, clothes, and linen, which finally affects peoples state of health. At dust pollution solar radiation losses reach 15 to 20 %. In particular ultra-violet radiation losses in summer reach 5%, in winter 39%, and in conditions of fog these losses reach 90 %.

13Negative influence upon a populations state of health

According to the data of many researches it is established that atmosphere pollution has a direct impact on health of people. The increased level of malignant tumors in lungs, increase in number of skin diseases, diseases of mucous membranes of eyes and of respiratory ways are observed. Besides various chronic diseases is sharply aggravated.The adverse influence of some atmospheric pollutant substances like lead, cadmium, etc. is manifested at their accumulation in bones and tissues, that can lead to development of chronic poisonings in population living near to sources of emissions.Influence of an even small concentrations of toxic substances can provoke aggravation of chronic diseases of respiratory system, shorten remissions, and raise frequency of complications if they affect the human body for a long time. More and more cases of specific diseases connected with atmospheric pollution are observed in populations which do not have professional contact with such toxic substances like fluorine, beryllium, cadmium, manganese, asbestos.Pollution of atmospheric air promotes the decrease of immuno-biological resistance of an organism, deterioration of indexes of physical development of children and teenagers, and increase of the general mortality.

14Sanitary protection of atmospheric air

Polluted atmospheric air possesses an ability to self-purification by various natural ways: by dilution, by sedimentation, by chemical reactions, washing away by an atmospheric precipitation (rain, snow) and absorption by green plantings.Decrease in concentration of air contaminants by dilution can occur by windy weather in direct ratio to a distance square. Heavy firm particles of water and a dust settle from air faster. An atmospheric precipitations in form of rain and snow remove (move away) from air both firm, and gaseous pollutants. Green plantings not only mechanically detain dust, but also are capable to absorb some gaseous impurities.Processes of self-purification proceed very slowly and can not cope with the modern rates of pollution; therefore natural processes alone can not provide sufficient purification (cleansing) of air.For this reason, special measures of sanitary protection of cleanliness of atmospheric air are requiredThese measures are divided on: legislative, planning, technological and sanitary-engineering.

15Legislative enactments:

Article 20 of the Federal law: "About sanitary-and-epidemiologic well-being of the population" (1999) says: "Atmospheric air in city and rural settlements, in territories of the industrial organizations, and also air in working zones of industrial premises, inhabited and other premises should not have harmful influence on the person".The further regulations of this law are specifically developed in such documents, as Sanitary Rules and Norms.For general orientation and carrying out of hygienic actions for decrease in impurities of atmospheric air, maximum permissible concentration (MPC) of air polluting contaminants are developed, and legislatively established. MPC is such concentration which does not render on the person neither direct, nor indirect harmful and unpleasant influence, does not reduce its work capacity, does not influence negatively its state of health and mood. There are two categories of MPC: Daily (once-only) Maximum, and Daily Average. The Once-only Maximum concentration is defined in a torch of emission of the enterprise to prevent sharp, reflex, irritating action of harmful substances on a human body. The Daily Average concentration is defined in any point to prevent general action of harmful substances on a human body.Now in a considerable quantity of cases these concentrations in the occupied places with the developed industry and motor transport are considerably exceeded16

Planning actions include:

1) Zoning of territory of settlements taking into account wind direction (wind-rose);2) An accomplishment of settlements for struggle against a dust (gardening, watering, paving and asphalting of streets);3) The organization of sanitary-protective zones,4) Integration of heating systems owing to liquidation of small home boilers.When choosing the place of an industrial zone seasonal wind-roses are used instead of the mid-annual wind-rose. The warm season should be taken into consideration at choice of location for chemical enterprises, and on the contrary, cold season should be taken into consideration at choice of location for thermal power stations.17Sanitary-protective zone (SPZ)

SPZ is the territory between borders of an industrial zone, warehouses, the agriculture enterprises (taking into account prospect of their expansion) from one hand and dwellings (inhabited zone) & building (business) from the other hand. SPZ is intended for:reduction of negative influence of the enterprises, transport, etc. on surrounding population;creation of an architecturally-aesthetic barrier between industrial and inhabited zones at their corresponding accomplishment;organization of additional planted areas intended for strengthening of natural cleansing of atmospheric air.The sizes of SPZ depend on the class of harmfulness of the enterprises (5 classes):1st -2000 m;2nd -1000 m;3rd - 500 m;4th - 300 m;5th - 100 m.An example of the industrial enterprises of the 1st class is manufacture of fertilizers, chlorine, fluorine, soot, rubber, cellulose etc. An example 5th class is paper from paper for recycling (spoilt sheet), factories of dry cleaning of clothes, etc.

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Technological measures:

1)Replace bio-hazard fuels with eco-safe substitutes (gasification and electrification)2)Replacement of harmful manufacturing substances with the harmless ones;3)Preliminary clearing of raw materials from harmful impurities;4)Using wet ways of processing of dusty materials rather than dry ways.5)Introduction of continuous technologies6)Increase in efficiency of processes of burning;7)Capture and recycle of valuable emissions with a view of their further uses.

19Sanitary-Engineering measures:

Sanitary-Engineering measures includes using of some modern devices such as: varies dust-, gas- and ashes-catchers.There are the list of cleansing devices: - Cyclones - catch to 50 % of a dust,- Multi-cyclones catch up to 65- 70 % of a dust,- Wet scrubbers catch up to 90 % of a dust and to 30 % of gases,- Fabric filters,- Electric filters - catch up to 96-98 % of a dust.20Modern cleansing devices usually installed within exhaust pipes. Than can trap up to 99 % of dust pollutants at using of combined methods. For reduction of air pollution by motor transport emissions the following method can be used:1. Accomplishment of the roads; 2. Building of underground (or elevated) pedestrian crossings;3. Building of efficient traffic intersections. All above-mentioned arrangements promote increase of speed of movement of cars so they dont need to stop. That in it's turn leads to a reduction of quantity of exhaust gases, as the greatest quantity of gases is emitted into atmosphere when cars have the greatest load on the engine, (when a car starts from a stop). For more than 20 years there has been mandatory installation of catalytic neutralizers located between the muffler and engine which traps some of the toxic components in automobiles emissions. In particular, such neutralizers convert post-combustion carbon monoxide of exhaust gases into carbon dioxide, which is less toxic (hence in USA they are called catalytic converters). The greatest ecological effect will be received, naturally, while internal combustion engine cars are replaced with electric motor cars (I mean creation of hydrogen, or electric cars). In this respect there are certain successes: pre-production models of electric cars are already created and have passed road tests. However, their mass commercialization has not been realized.The protection of atmospheric air from pollution is a great challenge. However the persisted problem is that realization of these actions demands considerable money investments. In particular, electric filters are the most effective of treatment facilities, but there building and their service are very expensive.

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Despite the economic obstacles, many of these actions are carried out, as they are vital and are mandated by state, national, & international laws. According to these laws, both building and operation of the manufactures negatively influencing a condition of atmosphere are forbidden. In this way the government agencies attempt to control the hygiene of the atmosphere by enacting of laws which authorize everything from car fuel efficiency (liter/km) and efficiency of appliances, to zoning & planning of cities, or regulation of work of the large enterprises. The atmosphere knows no time zones or international boundaries, its a global problem so we all must work together, to protect our Earth from air pollution!

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THANK YOU23