Tab. 1. Shells of the Earth

Name	ATMOSPHERE	HYDROSPHERE	BIOSPHERE
Description	An air shell, the lower boundaries of which run along the surface of the hydrosphere and lithosphere, and the upper one is located at a distance of about 1 thousand km. It consists of the ionosphere, stratosphere and troposphere.	It occupies 71% of the Earth's surface. Average salinity- 35 g/l, temperature fluctuates from 3-32 °C. The sun's rays penetrate to a depth of 200 m, and ultraviolet - up to 800 m.	Includes all living organisms that inhabit the atmosphere, hydrosphere and lithosphere.
Name	LITHOSPHERE	PYROSPHERE	CENTROSPHERE
Description	Solid, stone shell, 5-80 km high.	The fiery shell, which is located directly under the lithosphere.	Also called the core of the Earth. It is located at a depth of 1800 km. Consists of metals: iron (Fe), nickel (Ni).

Definition.Lithosphere - This is the solid shell of the Earth, consisting of the earth's crust and the upper layer - the mantle. Its thickness is different, for example, on the continents - from 40-80 km, and under the seas and oceans - 5-10 km. The composition of the earth's crust includes eight elements (Table 2, Fig. 2-9).

Tab. 2. The composition of the earth's crust

Name	Image	Name	Image
Oxygen (O 2)	Rice. 2. Oxygen ()	Iron (Fe)
Silicon (Si)		Magnesium (Mg)
Hydrogen (H 2)		Calcium (Ca)
Aluminum (Al)	Rice. 5. Aluminum ()	Sodium (Na)

The Earth's lithosphere is not uniform. Many scientists believe that it is divided by deep-sea faults into separate pieces - plates. These plates are in constant motion. Thanks to the softened layer of the mantle, this movement is not noticeable to a person, since it occurs very slowly. But when the plates collide, earthquakes occur, volcanoes, mountain ranges can form. In general, the total land area of ​​the Earth is 148 million km2, of which 133 million km2 are habitable.

Definition.The soil- this is the upper fertile layer of the earth, which is the habitat for many living organisms. The soil is connecting link between hydro-, litho- and atmosphere. The lithosphere is necessary for plants, fungi, animals and humans, therefore it is so important to protect and protect it. Let's consider the main sources of pollution of the lithosphere (Table 3, Fig. 10-14).

Tab. 3. Sources of pollution of the lithosphere

	Description	Image
	Residential buildings and utilities, from which there is a large amount of construction debris, food waste.	Rice. 10. Garbage, waste ()
	The negative impact is also industrial enterprises, because their liquid, solid and gaseous wastes enter the lithosphere.	Rice. 11. Waste from industrial enterprises ()
	Impact Agriculture, expressed in pollution with biological waste and pesticides.	Rice. 12. Agricultural waste ()
	radioactive waste, as a result of the Chernobyl disaster, the products of the release and half-life of radioactive substances adversely affect any living organism.	Rice. 13. Radioactive waste ()
	Traffic fumes emanating from transport, which settle in the soil and enter the cycle of substances.	Rice. 14. Exhaust ()

Exhaust gases contain a lot of heavy metals. So, scientists have calculated that the largest amount of heavy metals falls on those soils that are in close proximity to highways, in which the concentration of heavy metals can be 30 times higher than the norm. Examples of heavy metals: lead (Pb), copper (Cu), cadmium (Cd).

Everyone should understand how important it is to keep the habitat of living organisms as clean as possible. To this end, many scientists are developing methods to combat pollutants (Table 4).

Tab. 4. Pollution control methods

	Method characteristic
	Organization of authorized landfills, which occupy vast areas, and the waste that they contain requires long-term processing with the participation of microorganisms and oxygen. Accordingly, harmful toxic substances are released into the Earth's atmosphere. It also leads to the reproduction of rodents and insects that are carriers of diseases.
	More effective way is organization of waste incineration plants, although burning waste also releases toxins into the Earth's atmosphere. They tried to purify them with water, but then these substances enter the hydrosphere.
	The best method is organization of waste processing plants, while part of the waste is processed into compost, which can be used in agriculture. Part of non-compostable substances can be reused. Examples: plastics, glass.

Thus, waste disposal is a problem for all mankind: both individual states and each person.

Definition.Hydrosphere- water shell of the Earth (Scheme 1).

Scheme 1. Composition of the hydrosphere

95.98% - seas and oceans;

2% - glaciers;

2% - groundwater;

0.02% - land waters: rivers, lakes, swamps.

The hydrosphere plays a vital role in the life of the planet. It accumulates heat and distributes it over all continents. Also, gaseous water vapor is formed from the surface of the oceans, which subsequently fall along with precipitation onto land. Thus, the hydrosphere interacts both with the atmosphere, forming clouds, and with the lithosphere, falling to the ground along with precipitation.

Water - unique substance, without which no organism can do, since it is involved in all metabolic processes. Water on earth can be in different states of aggregation.

Once upon a time, it was in the water that the very first living organisms originated. And even today, all living organisms are in close relationship with water.

Production and industrial enterprises are trying to concentrate in the immediate vicinity of water bodies: rivers or large lakes. In the modern world, water is the main factor determining production, and often participating in it.

The importance of the hydrosphere can hardly be overestimated, especially now, when the growth rate of water supply and water consumption is increasing every day. Many states do not have drinking water in the required quantity, so our task is to keep the water clean.

Let us consider the main sources of pollution of the hydrosphere (Table 5).

Tab. 5. Sources of pollution of the hydrosphere

Tab. 6. Preservation measures for clean water

Today, the human factor is the main influencing link on nature, on all living organisms without exception. But we must not forget that the biosphere can do without us, but we cannot live without it. We need to learn how to live in harmony with nature, and for this we need to cultivate ecological thinking.

The next lesson will be devoted to the measures that are being taken to save life on Earth.

Bibliography

1. Melchakov L.F., Skatnik M.N., Natural history: textbook. for 3, 5 cells. avg. school - 8th ed. - M.: Enlightenment, 1992. - 240 p.: ill.
2. Pakulova V.M., Ivanova N.V. Nature: inanimate and living 5. - M .: Bustard.
3. Eskov K.Yu. and others / ed. Vakhrusheva A.A. Natural History 5. - M.: Balass.

1. Referat.znate.ru ().
2. miteigi-nemoto.livejournal.com ().
3. Dinos.ru ().

Homework

1. Melchakov L.F., Skatnik M.N., Natural History: Proc. for 3, 5 cells. avg. school - 8th ed. - M.: Enlightenment, 1992. - p. 233, assignment questions. 13.
2. Tell us what you know about methods of dealing with pollutants in the lithosphere.
3. Tell us about the methods of preserving a clean hydrosphere.
4. * Prepare an abstract

Mantle of the Earth- the shell of the "solid" Earth, located between the earth's crust and the core of the Earth. It occupies 83% of the Earth (without atmosphere) by volume and 67% by mass.

It is separated from the earth's crust by the Mohorovic surface, on which the velocity of the longitudinal seismic waves when moving from the crust to the mantle of the earth, it increases abruptly from 6.7-7.6 to 7.9-8.2 km/sec; The mantle is separated from the core of the Earth by the surface (at a depth of about 2900 km), at which the velocity of seismic waves drops from 13.6 to 8.1 km/sec. The Earth's mantle is divided into lower and upper mantle. The latter, in turn, is divided (from top to bottom) into the substrate, the Gutenberg layer (a layer of low seismic wave velocities) and the Golitsyn layer (sometimes called the middle mantle). At the base of the Earth's mantle, a layer less than 100 km thick is distinguished, in which the velocities of seismic waves do not increase with depth or even slightly decrease.

It is assumed that the Earth's mantle is composed of those chemical elements that, during the formation of the Earth, were in a solid state or were part of solid chemical compounds. Of these elements, O, Si, Mg, Fe predominate. According to modern concepts, the composition of the Earth's mantle is considered to be close to that of stony meteorites. Of the stony meteorites, chondrites have the closest composition to the Earth's mantle. It is assumed that the direct samples of the mantle substance are rock fragments among basalt lava, brought to the surface of the Earth; they are also found together with diamonds in explosion pipes. It is also believed that the rock fragments raised by the dredge from the bottom of the rifts of the Mid-Ocean Ridges are the substance of the mantle.

characteristic feature the Earth's mantle are, apparently, phase transitions. It has been experimentally established that in olivine, under high pressure, the structure of the crystal lattice changes, a denser packing of atoms appears, so that the volume of the mineral noticeably decreases. In quartz, such a phase transition is observed twice as the pressure increases; the densest modification is 65 °C denser than regular quartz. Such phase transitions are believed to be the main reason why seismic wave velocities in the Golitsyn layer increase very rapidly with depth.

Upper mantle one of the shells of the globe directly underlying the earth's crust. It is separated from the last Mohorovichi by a surface located under the continents at a depth of 20 to 80 km (35 km on average) and under the oceans at a depth of 11-15 km from the water surface. Seismic wave velocity (used as an indirect method for studying internal structure Earth) increases in the transition from the earth's crust to the upper mantle stepwise from approximately 7 to 8 km/s. ). The zone within the depths of 400-900 km is called the Golitsyn layer. The upper mantle is probably composed of garnet peridotites with an admixture in the upper part of the Eclogite.

Eclogite is a metamorphic rock consisting of pyroxene with a high content of quartz and rutile (a mineral containing an admixture of iron, tin, niobium and tantalum TiO 2 - 60% titanium and 40% oxygen).

An important structural feature of the upper mantle - the presence of a zone of low seismic wave velocities. There are differences in the structure of the upper mantle under different tectonic zones, for example, under geosynclines and platforms. In the upper mantle, processes are developing that are the source of tectonic, magmatic and metamorphic phenomena in the earth's crust. In many tectonic hypotheses, the upper mantle is given an important role; for example, it is assumed that the earth's crust was formed by melting from the substance of the upper mantle , that tectonic movements are associated with movements in the upper mantle; It is usually believed that the Earth's mantle is almost completely composed of olivine [(Mg, Fe) 2 SiO 4 ], in which the magnesium component (forsterite) strongly predominates, but with depth, perhaps, the proportion of the iron component (fayalite) increases. The Australian petrographer Ringwood suggests that the Earth's mantle is composed of a hypothetical rock, which he called pyrolite and which in composition corresponds to a mixture of 3 parts periodite and 1 part basalt. Theoretical calculations show that minerals in the lower mantle of the Earth should decompose into oxides. By the beginning of the 70s of the 20th century, data also appeared indicating the presence of horizontal inhomogeneities in the Earth's mantle.

There is no doubt that the earth's crust separated from the Earth's mantle; The process of differentiation of the Earth's mantle continues today. There is an assumption that the Earth's core is growing due to the Earth's mantle. The processes in the Earth's crust and the Earth's mantle are closely related; in particular, the energy for tectonic movements of the earth's crust appears to come from the earth's mantle.

Earth's lower mantle- an integral part of the Earth's mantle, extending from depths of 660 (boundary with the upper mantle) to 2900 km. The calculated pressure in the lower mantle is 24-136 GPa and the material of the lower mantle is not available for direct study.

In the lower mantle there is a layer (layer D) in which the velocity of seismic waves is anomalously low and has horizontal and vertical inhomogeneities. It is assumed that it is formed by the upward penetration of Fe and Ni into silicates, which are melted by these flows. This is extremely important, as some researchers believe that parts of the subduction plate accumulate 660 km from the boundary, and they become exponentially heavier and sink to the core and accumulate in the D layer.

Earth's crust- the outermost of the solid shells of the Earth. The lower boundary of the earth's crust is considered to be the interface, during the passage of which from top to bottom, longitudinal seismic waves abruptly increase the speed from 6.7-7.6 km / s to 7.9-8.2 km / s (see Mohorovicic surface). This is a sign of a change from a less elastic material to a more elastic and denser one. The layer of the upper mantle that underlies the earth's crust is often referred to as the substratum. Together with the earth's crust, it makes up the lithosphere. The earth's crust is different on the continents and under the ocean. The continental crust usually has a thickness of 35-45 km, in areas mountainous countries- up to 70 km. The upper part of the continental crust is made up of a discontinuous sedimentary layer, consisting of unaltered or slightly altered sedimentary and volcanic rocks of different ages. The layers are often crumpled into folds, torn and displaced along the gap. In some places (on shields) the sedimentary shell is absent. The rest of the thickness of the continental crust is divided according to the speed of seismic waves into 2 parts with conditional names: for the upper part - the "granite" layer (the speed of longitudinal waves is up to 6.4 km / s), for the lower part - the "basalt" layer (6.4 -7.6 km/s). Apparently, the "granite" layer is composed of granites and gneisses, and the "basalt" layer is composed of basalts, gabbro and very strongly metamorphosed sedimentary rocks in various proportions. These 2 layers are often separated by a Konrad surface, at the transition of which the seismic wave velocities increase abruptly. Apparently, the content of silica decreases with depth in the earth's crust and the content of iron and magnesium oxides increases; this takes place to an even greater extent during the transition from the earth's crust to the substratum.

The oceanic crust has a thickness of 5-10 km (together with the water column - 9-12 km). It is divided into three layers: under a thin (less than 1 km) layer of marine sediments lies the "second" layer with longitudinal seismic wave velocities of 4-6 km/sec; its thickness is 1-2.5 km. It is probably composed of serpentinite and basalt, possibly with interlayers of sediments. The lower, "oceanic" layer, with an average thickness of about 5 km, has a seismic wave velocity of 6.4-7.0 km/sec; it is probably composed of gabbro. The thickness of the layer of sediments at the bottom of the ocean is variable, in places there is none at all. In the transition zone from the mainland to the ocean, an intermediate type of crust is observed.

The earth's crust is subject to constant movements and change. In her irreversible development mobile areas - geosynclines - turn through long-term transformations into relatively calm areas - platforms. There are a number of tectonic hypotheses that explain the process of development of geosynclines and platforms, continents and oceans, and the reasons for the development of the earth's crust as a whole. There is no doubt that the main causes of the development of the earth's crust lie in the deeper interior of the earth; therefore, the study of the interaction between the earth's crust and the upper mantle is of particular interest.

The earth's crust is close to a state of isostasy (equilibrium): the heavier, i.e., the thicker or denser any part of the earth's crust, the deeper it is immersed in the substrate. Tectonic forces break isostasy, but when they weaken, the earth's crust returns to equilibrium.

Figure 25 - Earth's crust

Earth's core - the central geosphere with a radius of about 3470 km. The existence of the Earth's core was established in 1897 by the German seismologist E. Wiechert, and the depth (2,900 km) was determined in 1910 by the American geophysicist B. Gutenberg. There is no consensus on the composition of the Earth's core and its origin. Perhaps it consists of iron (with an admixture of nickel, sulfur, silicon or other elements) or its oxides, which, under the action of high pressure acquire metallic properties. There are opinions that the core was formed by gravitational differentiation of the primary Earth during its growth or later (first expressed by the Norwegian geophysicist V.M. Orovan and Soviet scientist A.P. Vinogradov, 60-70s).

Mohorovic surface - the interface between the Earth's crust and the Earth's mantle. The Mohorovichi surface was established from seismic data: the velocity of longitudinal seismic waves during the transition (from top to bottom) through the Mohorovichi surface increases abruptly from 6.7-7.6 to 7.9-8.2 km / s , and transverse - from 3.6-4.2 to 4.4-4.7 km / s. Various geophysical, geological and other data indicate that the density of matter also increases abruptly, presumably from 2.9-3 to 3.1-3.5 t/m 3 . It is most probable that the Mohorovic surface separates layers of different chemical composition. Mohorovichić surface is named after A. Mohorovichić, who discovered it.

Of the first three geospheres, the leading role undoubtedly belongs to the earth's crust, since its total mass is many times greater than the total mass of the other two shells. Therefore, data on the relative content of one or another chemical element in the earth's crust can to a large extent be considered as reflecting its content in the biosphere as a whole.

The outer hard shell of the Earth - the earth's crust is more than 99% composed of only 9 main elements: O (47%), Si (29.5%), Al (8.05%), Fe (4.65%), Ca ( 2.96%), Na (2.50%), K (2.50%), Mg (1.87%), Ti (0.45%). In total - 99.48%. Of these, oxygen is absolutely predominant. You can clearly see how much is left for all other elements. This is by weight, that is, in weight percent.

There is another variant of evaluation - by volume (volume percent). It is calculated taking into account the sizes of atomic and ionic radii in specific mineral compounds formed by these elements. The contents in the earth's crust of the most common elements in volume percentages are (according to V.M. Goldshmidt): O - 93.77%, K - 2.14%, Na - 1.60%, Ca - 1.48%, Si - 0.86%, Al - 0.76%, Fe - 0.68%, Mg - 0.56%, Ti - 0.22%.

Quite significant differences in the distribution of atoms of chemical elements by weight and volume are obvious: in a sharp decrease in the relative content of Al and especially Si (due to the small size of their atoms, and for silicon, to an even greater extent of ions in its oxygen compounds), it is even more clearly emphasized the leading role of oxygen in the lithosphere.

At the same time, "anomalies" in the contents of some elements in the lithosphere were revealed:

the “dip” in the abundances of the lightest elements (Li, Be, B) is explained by the peculiarities of the nucleosynthesis process (the predominant formation of carbon as a result of the combination of three helium nuclei at once); relatively high contents of elements that are products of radioactive decay (Pb, Bi, and also Ar among the inert gases).

Under Earth conditions, the abundances of two more elements, H and He, are anomalously low. This is due to their "volatility". Both of these elements are gases, and, moreover, the lightest. Therefore, atomic hydrogen and helium tend to move into the upper layers of the atmosphere, and from there, not being held by Earth's gravity, they disperse into outer space. Hydrogen has not yet been completely lost, since most of it is part of chemical compounds - water, hydroxides, hydrocarbonates, hydrosilicates, organic compounds and others. And helium, which is an inert gas, is constantly formed as a product of the radioactive decay of heavy atoms.

Thus, the earth's crust is essentially a package of oxygen anions bonded to each other by silicon and metal ions, i.e. it consists almost exclusively of oxygen compounds, mainly from silicates of aluminum, calcium, magnesium, sodium, potassium and iron. At the same time, as you already know, even elements account for 86.5% of the lithosphere.

The most common elements are called macronutrients.

Elements, the content of which is hundredths of a percent or less, are called microelements. This concept is relative, since a particular element can be a microelement in one environment, and in another it can be classified as basic, i.e. macroelements (For example, Al in organisms is a trace element, and in the lithosphere it is a macroelement, iron in soils is a macroelement, and in living organisms it is a trace element).

To denote the amount of content of a particular element in a particular environment, the concept of "clark" is used. This term is associated with the name F.U. Clark, an American geochemist, who was the first to undertake, on the basis of extensive analytical material, the calculation of the average contents of chemical elements in various types of rocks and in the lithosphere as a whole. In memory of his contribution, A.E. Fersman in 1924 suggested calling the average content of any particular element in a particular material medium the clarke of this chemical element. The clarke unit is g/t (since it is inconvenient to use percentage values ​​at low clarks of many elements).

Most challenging task is the definition of clarks for the lithosphere as a whole, since its structure is very.

Inside the rocks, the division of silicates is carried out into acidic and basic.

The concentrations of Li, Be, Rb, TR, Ba, Tl, Th, U, and Ta are relatively elevated in acidic ones.

The main ones are Cr, Sc, Ni, V, Co, Pt.

We give the order of clarks various elements according to V.F. Barabanov:

More than 10,000 g/t - O, Si, Al, Fe, Ca, Mg, Na, K.

1000-10 000 - Mn, Ti.

100-1000 - C, F, P, S, Cl, Rb, Sr, Zr, Ba.

10-100 - Pb, Th, Y, Nb, La, Ce, Nd, Li, B, N, Sc, V, Cr, Co, Ni, Cu, Zn, Ga.

1-10 - Eu, Dy, Ho, Er, Yb, Hf, Ta, W, Tl, U, Ge, As, Br, Mo, Sn, Sc, Pm, Sm, Be.

0.1-1.0 - Cd, Bi, In, Tu, I, Sb, Lu.

0.01-0.1 - Ar, Se, Ag, Hg.

0.001-0.01 - Re, Os, Ir, Ru, Rh, Pd, Te, Pt, He, Au.

According to this gradation, elements with clarks above 1000 g/t will be referred to as macroelements. Those with lower clarks are trace elements.

Accounting for clarkes is certainly necessary for a correct understanding of the regularities of the processes of migration of chemical elements. The different distribution of elements in nature has an inevitable consequence for many of them, the presence of significant differences in their behavior in laboratory conditions and in nature. As the clarke decreases, the active concentration of the element decreases, and it becomes impossible for an independent solid phase to precipitate from aqueous solutions and other methods for the formation of independent mineral species. Therefore, the ability for independent mineral formation depends not only on the chemical properties of the element, but also on its clarke.

Examples: S and Se are chemically complete analogues, and their behavior in natural processes is different. S is the leading element of many natural processes. Hydrogen sulfide plays big role in chemical processes occurring in bottom sediments and in the depths of the earth's crust, in the formation of deposits of a number of metals. Sulfur forms independent minerals (sulfides, sulfates). Hydrogen selenide does not play a significant role in natural processes. Selenium is found in a dispersed state as an impurity in minerals formed by other elements. The differences between K and Cs, Si and Ge are similar.

One of the most important differences between geochemistry and chemistry is that geochemistry considers only those chemical interactions that are realized in specific natural conditions. In addition, accounting for clarks (according to at least their orders) in this sense is a primary requirement for any geochemical constructions.

There are, and even quite common, independent mineral phases of a number of elements with low clarks. The reason is that in nature there are mechanisms that make it possible to ensure the formation of increased concentrations of certain elements, as a result of which their content in some areas can be many times higher than the clarke ones. Therefore, in addition to the clarke of the element, it is necessary to take into account the value of its concentration in comparison with the clarke content.

The concentration clarke is the ratio of the content of a chemical element in a given particular natural material aggregate (rock, etc.) to its clarke.

Examples of concentration coefficients of some chemical elements in their ore deposits: Al - 3.7; Mn - 350; Cu - 140; Sn - 250; Zn - 500; Au-2000.

On this basis, elements with low clarks are subdivided into two qualitatively already known to you various groups. Those whose distribution is not characterized by high values ​​of QC are called scattered(Rb, Ga, Re, Cd, etc.). Able to form elevated concentrations with high CC values ​​- rare(Sn, Be, etc.).

Differences in the achieved QC values ​​are due to different role certain elements in the history of the material and technical activity of mankind (since ancient times, known metals with low clarks Au, Cu, Sn, Pb, Hg, Ag ... - and more common Al, Zr ...).

An important role in the processes of concentration and dispersion of elements in the earth's crust is played by isomorphism - the property of elements to replace each other in the structure of the mineral. Isomorphism is the ability of chemical elements with similar properties to replace each other in varying amounts in crystal lattices. Of course, it is characteristic not only of microelements. But it is precisely for them, especially for scattered elements, that it acquires leading significance as the main factor in the regularity of their distribution. A distinction is made between perfect isomorphism - when interchangeable elements can replace each other in any ratio (limited only by the ratios of the contents of these elements in the system), and imperfect - when substitution is possible only up to certain limits. Naturally, the closer the chemical properties, the more perfect the isomorphism.

A distinction is made between isovalent and heterovalent isomorphism.

Generality of type chemical bond- what chemists call the degree of ionicity - covalence. Example: chlorides and sulfides are not isomorphic, but sulfates with manganates are isomorphic.

Mechanism of isovalent isomorphism. The uniformity of the chemical formula of the formed compounds and the formed crystal lattice. That is, if rubidium is potentially capable of forming compounds with the same elements as potassium, and the crystal structure of such compounds is of the same type, then rubidium atoms can replace potassium atoms in its compounds.

The division of chemical elements into macro- and microelements, and the latter into rare and scattered ones, is of great importance, since in nature not all chemical elements form independent compounds. This is characteristic mainly of elements with high clarks, or with low clarks, but capable of locally forming high concentrations (that is, rare).

Being in nature in a diffuse state and everywhere (only in various concentrations) is a property of all chemical elements. This fact was first stated by V.I. Vernadsky, and he received the name of the law of scattering of chemical elements by Vernadsky. But part of the elements is capable of being present in nature in addition to the scattered form of being in another form - in the form of chemical compounds. And elements with low concentrations are present only in a diffuse form.

Mechanism of heterovalent isomorphism somewhat more complicated. For the first time, the presence of this type of isomorphism drew attention to late XIX in. G. Chermak. He proved that very complex chemical formulas, obtained for most mineral compounds of the silicate class, are such precisely because of heterovalent isomorphism, when whole groups of atoms mutually replace each other. This type of isomorphism is very characteristic of silicate compounds.

Other options for finding scattered atoms of elements in the earth's crust are their localization in defects crystal lattice, in its cavities, and also in the adsorbed state on the surface of other particles, including colloidal ones.

Planet Earth consists of the lithosphere (solid body), atmosphere (air shell), hydrosphere (water shell) and biosphere (sphere of distribution of living organisms). Between these spheres of the Earth there is close relationship due to the circulation of matter and energy.

Lithosphere. The Earth is a ball, or spheroid, somewhat flattened at the poles, with a circumference around the equator of about 40,000 km.

In the structure of the globe, the following shells, or geospheres, are distinguished: the lithosphere itself (the outer stone shell) with a thickness of about 50 ... 120 km, the mantle extending to a depth of 2900 km and the core - from 2900 to 3680 km.

According to the most common chemical elements that make up the Earth's shell, it is divided into the upper - siallitic, which extends to a depth of 60 km and has a density of 2.8 ... having a density of 3.0...3.5 g/cm 3 . The names "siallitic" (sial) and "simatic" (sima) shells come from the designations of the elements Si (silicon), Al (aluminum) and Mg (magnesium).

At a depth of 1200 to 2900 km there is an intermediate sphere having a density of 4.0...6.0 g/cm 3 . This shell is called "ore", as it contains a large amount of iron and other heavy metals.

Deeper than 2900 km is the core of the globe with a radius of about 3500 km. The core consists mainly of nickel and iron and has a high density (10...12 g/cm3).

According to the physical properties of the earth's crust is heterogeneous, it is divided into continental and oceanic types. The average thickness of the continental crust is 35...45 km, the maximum thickness is up to 75 km (under mountain ranges). Sedimentary rocks up to 15 km thick lie in its upper part. These rocks were formed over long geological periods as a result of the change of seas by land, climate change. Under the sedimentary rocks there is a granite layer with an average thickness of 20...40 km. The thickness of this layer is greatest in the areas of young mountains, it decreases towards the periphery of the mainland, and there is no granite layer under the oceans. Under the granite layer there is a basalt layer with a thickness of 15...35 km, it is composed of basalts and similar rocks.

The oceanic crust is less thick than the continental crust (from 5 to 15 km). The upper layers (2...5 km) consist of sedimentary rocks, and the lower (5...10 km) - of basalt.

Sedimentary rocks located on the surface of the earth's crust serve as the material basis for soil formation; igneous and metamorphic rocks take a small part in the formation of soils.

The main mass of rocks is formed by oxygen, silicon and aluminum (84.05%). If five more elements are added to these three elements - iron, calcium, sodium, potassium and magnesium, then in total they will amount to 98.87% of the rock mass. The remaining 88 elements account for slightly more than 1% of the mass of the lithosphere. However, despite the low content of micro- and ultramicroelements in rocks and soils, many of them are of great importance for the normal growth and development of all organisms. At present, much attention is paid to the content of microelements in the soil, both in connection with their importance in plant nutrition, and in connection with the problems of protecting soils from chemical pollution. The composition of elements in soils mainly depends on their composition in rocks. However, the content of some elements in rocks and soils formed on them varies somewhat. This is connected both with the concentration of nutrients and with the course of the soil-forming process, during which a relative decrease in a number of bases and silica occurs. Thus, soils contain more oxygen than the lithosphere (respectively 55 and 47%), hydrogen (5 and 0.15%), carbon (5 and 0.1%), nitrogen (0.1 and 0.023%).

Atmosphere. The boundary of the atmosphere passes where the force of the earth's gravity is compensated by the centrifugal force of inertia due to the rotation of the Earth. Above the poles, it is located at an altitude of about 28 thousand km, and above the equator - 42 thousand km.

The atmosphere consists of a mixture of various gases: nitrogen (78.08%), oxygen (20.95%), argon (0.93%) and carbon dioxide (0.03% by volume). The composition of the air also includes a small amount of helium, neon, xenon, krypton, hydrogen, ozone, etc., which in total are about 0.01%. In addition, the air contains water vapor and some dust.

The atmosphere consists of five main shells: troposphere, stratosphere, mesosphere, ionosphere, exosphere.

Troposphere- the lower layer of the atmosphere, has a thickness above the poles of 8 ... 10 km, in temperate latitudes - 10 ... 12 km, and in equatorial latitudes - 16 ... 18 km. About 80% of the mass of the atmosphere is concentrated in the troposphere. Almost all of the water vapor in the atmosphere is located here, precipitation is formed and air moves horizontally and vertically.

Stratosphere extends from 8...16 to 40...45 km. It includes about 20% of the atmosphere, water vapor is almost absent in it. There is a layer of ozone in the stratosphere that absorbs ultraviolet radiation from the sun and protects living organisms on Earth from death.

Mesosphere extends at an altitude of 40 to 80 km. The density of air in this layer is 200 times less than that of the earth's surface.

Ionosphere located at an altitude of 80 km and consists mainly of charged (ionized) oxygen atoms, charged nitric oxide molecules and free electrons.

Exosphere represents the outer layers of the atmosphere and starts from a height of 800 ... 1000 km from the Earth's surface. These layers are also called the scattering sphere, since here gas particles move with high speed and can escape into outer space.

Atmosphere It is one of the indispensable factors of life on Earth. The sun's rays, passing through the atmosphere, are scattered, as well as partially absorbed and reflected. Water vapor and carbon dioxide absorb heat rays especially strongly. Moving under the influence of solar energy air masses climate is formed. Precipitation falling from the atmosphere is a factor in soil formation and a source of life for plant and animal organisms. The carbon dioxide contained in the atmosphere in the process of photosynthesis of green plants turns into organic matter, and oxygen serves for the respiration of organisms and oxidative processes occurring in them. The importance of atmospheric nitrogen, which is captured by nitrogen-fixing microorganisms, serves as an element of plant nutrition and participates in the formation of protein substances.

Under the influence atmospheric air weathering of rocks and minerals and soil-forming processes occur.

Hydrosphere. Most of the surface of the globe is occupied by the World Ocean, which, together with lakes, rivers and other bodies of water located on the earth's surface, occupies 5/8 of its area. All the waters of the Earth, located in the oceans, seas, rivers, lakes, swamps, as well as groundwater, constitute the hydrosphere. Of the 510 million km 2 of the Earth's surface, 361 million km 2 (71%) falls on the World Ocean and only 149 million km 2 (29%) is on land.

The surface waters of the land, together with the glacial waters, make up about 25 million km 3, that is, 55 times less than the volume of the World Ocean. About 280 thousand km 3 of water are concentrated in the lakes, about half of them are fresh lakes, and the second half are lakes with waters of varying degrees of salinity. The rivers contain only 1.2 thousand km 3, that is, less than 0.0001% of the total water supply.

The waters of open reservoirs are in constant circulation, which connects all parts of the hydrosphere with the lithosphere, atmosphere and biosphere.

Atmospheric moisture is actively involved in water exchange, with a volume of 14 thousand km 3 it forms 525 thousand km 3 of precipitation falling on the Earth, and the entire volume of atmospheric moisture changes every 10 days, or 36 times during the year.

Evaporation of water and condensation of atmospheric moisture provide fresh water on Earth. About 453 thousand km 3 of water evaporates annually from the surface of the oceans.

Without water, our planet would be bare stone ball devoid of soil and vegetation. For millions of years, water has destroyed rocks, turning them into junk, and with the advent of vegetation and animals, it has contributed to the process of soil formation.

Biosphere. The composition of the biosphere includes the land surface, the lower layers of the atmosphere and the entire hydrosphere, in which living organisms are common. According to the teachings of V. I. Vernadsky, the biosphere is understood as the shell of the Earth, the composition, structure and energy of which are determined by the activity of living organisms. V. I. Vernadsky pointed out that “there is no chemical force more permanent, therefore more powerful than living organisms taken as a whole. Life in the biosphere develops in the form of an exceptional variety of organisms inhabiting the soil, the lower layers of the atmosphere and the hydrosphere. Thanks to the photosynthesis of green plants, solar energy is accumulated in the biosphere in the form of organic compounds. The whole set of living organisms ensures the migration of chemical elements in soils, in the atmosphere and hydrosphere. Under the action of living organisms, gas exchange, oxidative and reduction reactions occur in soils. The origin of the atmosphere as a whole is connected with the gas exchange function of organisms. In the process of photosynthesis in the atmosphere, the formation and accumulation of free oxygen occurred.

Under the influence of the activity of organisms, weathering of rocks and the development of soil-forming processes are carried out. Soil bacteria are involved in the processes of desulfification and denitrification with the formation of hydrogen sulfide, sulfur compounds, N(II) oxide, methane, and hydrogen. The construction of plant tissues occurs due to the selective absorption of biogenic elements by plants. After the plants die, these elements accumulate in the upper soil horizons.

In the biosphere, two cycles of substances and energy, opposite in their direction, take place.

A large, or geological, cycle occurs under the influence of solar energy. The water cycle involves the chemical elements of the land, which enter the rivers, seas and oceans, where they are deposited along with sedimentary rocks. This is an irretrievable loss from the soil of the most important plant nutrients (nitrogen, phosphorus, potassium, calcium, magnesium, sulfur), as well as trace elements.

A small, or biological, cycle takes place in the system soil - plants - soil, while plant nutrients are removed from the geological cycle and stored in humus. In the biological cycle, cycles occur associated with oxygen, carbon, nitrogen, phosphorus and hydrogen, which continuously circulate in plants and the environment. Some of them are withdrawn from the biological cycle and, under the influence of geochemical processes, pass into sedimentary rocks or are transferred to the ocean. The task of agriculture is to create such agrotechnical systems in which biogenic elements would not enter geological cycle, but were fixed in the biological cycle, maintaining soil fertility.

The biosphere consists of biocenoses, which are a homogeneous territory with the same type of plant community along with the animal world inhabiting it, including microorganisms. Biogeocenosis is characterized by its characteristic soils, water regime, microclimate and topography. Natural biogeocenosis is relatively stable, it is characterized by self-regulating ability. The species included in the biogeocenosis adapt to each other and the environment. This is a complex relatively stable mechanism capable of resisting changes in the environment through self-regulation. If changes in biogeocenoses exceed their self-regulating ability, then irreversible degradation of this ecological system may occur.

Agricultural lands are artificially organized biogeocenoses (agrobiocenoses). The effective and rational use of agrobiocenoses, their sustainability and productivity depend on the proper organization of the territory, the farming system and other socio-economic activities. To provide optimal impact on soils and plants, it is necessary to know all the relationships in the biogeocenosis and not disturb the ecological balance that has developed in it.

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Introduction

The rapid growth of the human population and its scientific and technical equipment have 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 impact force was incomparably less than the powerful circulation 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 an increase in the power of anthropogenic influence on the biosphere.

The danger of unpredictable changes in the stable state of the biosphere to which they are historically adapted natural communities and species, including man himself, is so great while maintaining the usual ways of managing that the current generations of people inhabiting the Earth have the task of urgently improving all aspects of their lives in accordance with the need to preserve the existing circulation of substances and energy in the biosphere. In addition, the widespread pollution of our environment with a variety of 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.

atmosphere hydrosphere lithosphere pollution

1. Air pollution

Atmospheric air is the most important life-supporting natural environment and is a mixture of gases and aerosols of the surface layer of the atmosphere, formed during the evolution of the Earth, human activity and located outside residential, industrial and other premises. results environmental research, both in Russia and abroad, unequivocally indicate that pollution of the surface atmosphere is the most powerful, constantly acting factor influencing humans, the food chain and the environment. Atmospheric air has an unlimited capacity and plays the role of the most mobile, chemically aggressive and all-penetrating agent of interaction near the surface of the components of the biosphere, hydrosphere and lithosphere.

AT last years data were obtained on the significant role of the ozone layer of the atmosphere for the preservation of the biosphere, which absorbs the ultraviolet radiation of the Sun, which is harmful to living organisms and forms a thermal barrier at altitudes of about 40 km, which prevents the cooling of the earth's surface.

The atmosphere has an intense impact not only on humans and biota, but also on the hydrosphere, soil and vegetation cover, geological environment, buildings, structures and other man-made objects. Therefore, the protection of atmospheric air and the ozone layer is the highest priority environmental problem and is given close attention in all developed countries.

The polluted surface atmosphere causes cancer of the lungs, throat and skin, a disorder of the central nervous system, allergic and respiratory diseases, defects in newborns and many other diseases, the list of which is determined by the pollutants present in the air and their combined effects on the human body. The results of special studies carried out in Russia and abroad have shown that there is a close positive relationship between the health of the population and the quality of atmospheric air.

The main agents of the influence of the atmosphere on the hydrosphere are precipitation in the form of rain and snow, in lesser degree smog, fog. The surface and underground waters of the land are mainly atmospheric nourishment and, as a result, their chemical composition depends mainly on the state of the atmosphere.

The negative impact of the polluted atmosphere on the soil and vegetation cover is associated both with the precipitation of acidic precipitation, which leaches calcium, humus and trace elements from the soil, and with the disruption of photosynthesis processes, leading to a slowdown in the growth and death of plants. High sensitivity trees (especially birch, oak) to air pollution has been identified for a long time. The combined action of both factors leads to a noticeable decrease in soil fertility and the disappearance of forests. Acid atmospheric precipitation is now considered as a powerful factor not only in the weathering of rocks and the deterioration of the quality of bearing soils, but also in the chemical destruction of man-made objects, including cultural monuments and land lines. Many economically developed countries are currently implementing programs to address the problem of acid precipitation. As part of the National Acid Rainfall Assessment Program, established in 1980, many US federal agencies began funding research into the atmospheric processes that cause acid rain to assess the impact of the latter on ecosystems and develop appropriate conservation measures. It turned out that acid rain has a multifaceted impact on the environment and is the result of self-purification (washing) of the atmosphere. The main acidic agents are dilute sulfuric and nitric acids formed during the oxidation reactions of sulfur and nitrogen oxides with the participation of hydrogen peroxide.

Sources of air pollution

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

The main natural process of pollution of the surface atmosphere is the volcanic and fluid activity of the Earth Major eruptions volcanoes lead to global and long-term pollution of the atmosphere, as evidenced by the chronicles and modern observational data (the eruption of Mount Pinatubo in the Philippines in 1991). This is due to the fact that huge amounts of gases are instantly emitted into the high layers of the atmosphere, which are picked up by high-speed air currents at high altitude 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 activities. These should include:

1. Burning fossil fuels, which is accompanied by the release of 5 billion tons of carbon dioxide per year. As a result, over 100 years (1860 - 1960), the content of CO2 increased by 18% (from 0.027 to 0.032%). Over the past three decades, the rates of these emissions have increased significantly. At such rates, by the year 2000 the amount of carbon dioxide in the atmosphere will be at least 0.05%.

2. The operation of thermal power plants, when acid rain is formed during the combustion of high-sulfur coals as a result of the release of sulfur dioxide and fuel oil.

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

4. Production activity.

5. Pollution with suspended particles (when crushing, packing and loading, from boiler houses, power plants, mine shafts, quarries when burning garbage).

6. Emissions by enterprises of various gases.

7. Combustion of fuel in flare furnaces, resulting in the formation of the most massive pollutant - carbon monoxide.

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

9. Ventilation emissions (mine shafts).

10. Ventilation emissions with excessive ozone concentration from rooms with high energy installations (accelerators, ultraviolet sources and nuclear reactors) at MPC in working rooms of 0.1 mg/m3. AT large quantities ozone is a highly toxic gas.

During the processes of fuel combustion, the most intense pollution of the surface layer of the atmosphere occurs in megacities and major cities, industrial centers due to the wide distribution of motor vehicles, thermal power plants, boiler houses and other power plants operating on coal, fuel oil, diesel fuel, natural gas and gasoline. The contribution of vehicles to the total air pollution here reaches 40-50%. A powerful and extremely dangerous factor in air pollution are catastrophes at nuclear power plants (Chernobyl accident) and tests 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 the contamination of the territory.

The high danger of chemical and biochemical industries lies in the potential for emergency emissions into the atmosphere of extremely toxic substances, as well as microbes and viruses that can cause epidemics among the population and animals.

Currently, many tens of thousands of pollutants of anthropogenic origin are found in the surface atmosphere. Due to the continued growth of industrial and agricultural production, new chemical compounds, including highly toxic ones, are emerging. The main anthropogenic air pollutants, in addition to large-tonnage oxides of sulfur, nitrogen, carbon, dust and soot, are complex organic, organochlorine and nitro compounds, man-made radionuclides, viruses and microbes. The most dangerous are dioxin, benz (a) pyrene, phenols, formaldehyde, and carbon disulfide, which are widespread in the air basin of Russia. Solid suspended particles are mainly represented by soot, calcite, quartz, hydromica, kaolinite, feldspar, less often sulfates, chlorides. Oxides, sulfates and sulfites, sulfides of heavy metals, as well as alloys and metals in native form were found in snow dust by specially developed methods.

In Western Europe, priority is given to 28 especially dangerous chemical elements, compounds and their groups. To the group organic matter includes acrylic, nitrile, benzene, formaldehyde, styrene, toluene, vinyl chloride, non-organic - heavy metals (As, Cd, Cr, Pb, Mn, Hg, Ni, V), gases (carbon monoxide, hydrogen sulfide, nitrogen and sulfur oxides, radon , ozone), asbestos. Mainly toxic effect render lead, cadmium. Intensive bad smell have carbon disulfide, hydrogen sulfide, styrene, tetrachloroethane, toluene. The impact halo of sulfur and nitrogen oxides extends over long distances. The above 28 air pollutants are included in the international registry of potentially toxic chemicals.

The main indoor air pollutants are dust and tobacco smoke, carbon monoxide and carbon dioxide, nitrogen dioxide, radon and heavy metals, insecticides, deodorants, synthetic detergents, drug aerosols, microbes and bacteria. Japanese researchers have shown that bronchial asthma may be associated with the presence of domestic ticks in the air of dwellings.

The atmosphere is characterized by extremely high dynamism, due to both the rapid movement of air masses in the lateral and vertical directions, and high speeds, a variety of physical and chemical reactions occurring in it. The atmosphere is now viewed as a huge "chemical cauldron" that is influenced by numerous and variable anthropogenic and natural factors. Gases and aerosols released into the atmosphere are highly reactive. Dust and soot generated during fuel combustion, forest fires absorb heavy metals and radionuclides and, when deposited on the surface, can pollute vast areas and enter the human body through the respiratory system.

The tendency of joint accumulation of lead and tin in solid suspended particles of the surface atmosphere of European Russia has been revealed; chromium, cobalt and nickel; strontium, phosphorus, scandium, rare earths and calcium; beryllium, tin, niobium, tungsten and molybdenum; lithium, beryllium and gallium; barium, zinc, manganese and copper. High concentrations of heavy metals in snow dust are due to both the presence of their mineral phases formed during the combustion of coal, fuel oil and other fuels, and the sorption of soot, clay particles of gaseous compounds such as tin halides.

The "lifetime" of gases and aerosols in the atmosphere varies in a very wide range (from 1 - 3 minutes to several months) and depends mainly on their chemical stability of size (for aerosols) and the presence of reactive components (ozone, hydrogen peroxide, etc.). .).

Estimating and even more so forecasting the state of the surface atmosphere is a very complex problem. At present, her condition is assessed mainly according to the normative approach. MPC values ​​for toxic chemicals and other standard air quality indicators are given in many reference books and guidelines. In such guidelines for Europe, in addition to the toxicity of pollutants (carcinogenic, mutagenic, allergenic and other effects), their prevalence and ability to accumulate in the human body and the food chain are taken into account. Disadvantages of the normative approach - unreliability accepted values MPC and other indicators due to the poor development of their empirical observational base, the lack of consideration of the joint impact of pollutants and abrupt changes in the state of the surface layer of the atmosphere in time and space. There are few stationary posts for monitoring the air basin, and they do not allow an adequate assessment of its condition in large industrial and urban centers. Needles, lichens, and mosses can be used as indicators of the chemical composition of the surface atmosphere. On the initial stage detection of centers of radioactive contamination associated with Chernobyl accident, studied pine needles, which have the ability to accumulate radionuclides in the air. Reddening of the needles of coniferous trees during periods of smog in cities is widely known.

The most sensitive and reliable indicator of the state of the surface atmosphere is the snow cover, which deposits pollutants over a relatively long period of time and makes it possible to determine the location of sources of dust and gas emissions using a set of indicators. Snowfall contains pollutants that are not captured by direct measurements or calculated data on dust and gas emissions.

To promising areas assessment of the state of the surface atmosphere of large industrial - urbanized areas includes multi-channel remote sensing. The advantage of this method lies in the ability to characterize large areas. To date, methods have been developed for estimating the content of aerosols in the atmosphere. The development of scientific and technological progress allows us to hope for the development of such methods in relation to other pollutants.

The forecast of the state of the surface atmosphere is carried out on the basis of complex data. These primarily include the results of monitoring observations, the patterns of migration and transformation of pollutants in the atmosphere, the features of anthropogenic and natural processes of pollution of the air basin of the study area, the influence of meteorological parameters, relief and other factors on the distribution of pollutants in the environment. For this purpose, heuristic models of changes in the surface atmosphere in time and space are developed for a particular region. The greatest success in solving this difficult problem achieved for the areas where nuclear power plants are located. The end result of applying such models is quantification risk of air pollution and assessment of its acceptability from a socio-economic point of view.

Chemical pollution of the atmosphere

Atmospheric pollution should be understood as a change in its composition when impurities of natural or anthropogenic origin enter. There are three types of pollutants: gases, dust and aerosols. The latter include dispersed particulate matter emitted into the atmosphere and in it long time in a balanced state.

The main atmospheric pollutants include carbon dioxide, carbon monoxide, sulfur and nitrogen dioxide, as well as small gas components that can affect the temperature regime of the troposphere: nitrogen dioxide, halocarbons (freons), methane and tropospheric ozone.

The main contribution to the high level of air pollution is made by enterprises of ferrous and non-ferrous metallurgy, chemistry and petrochemistry, construction industry, energy, pulp and paper industry, and in some cities, boiler houses.

Sources of pollution - thermal power plants, which, together with smoke, emit sulfur dioxide and carbon dioxide into the air, metallurgical enterprises, especially non-ferrous metallurgy, which emit nitrogen oxides, hydrogen sulfide, chlorine, fluorine, ammonia, phosphorus compounds, particles and compounds of mercury and arsenic into the air; chemical and cement plants. Harmful gases enter the air as a result of fuel combustion for industrial needs, home heating, transport, combustion and processing of household and industrial waste.

Atmospheric pollutants are divided into primary, entering directly into the atmosphere, and secondary, resulting from the transformation of the latter. So, sulfur dioxide entering the atmosphere is oxidized to sulfuric anhydride, which interacts with water vapor and forms droplets of sulfuric acid. When sulfuric anhydride reacts with ammonia, ammonium sulfate crystals are formed. Similarly, as a result of chemical, photochemical, physico-chemical reactions between pollutants and atmospheric components, other secondary signs are formed. The main source of pyrogenic pollution on the planet are thermal power plants, metallurgical and chemical enterprises, boiler plants that consume more than 170% of the annually produced solid and liquid fuels.

Car emissions account for a large share of air pollution. Now about 500 million cars are operated on Earth, and by the year 2000 their number is expected to increase to 900 million. In 1997, 2400 thousand cars were operated in Moscow, with the standard of 800 thousand cars for existing roads.

Currently on the share 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 run 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 near the main road (up to 10 m), residents get cancer 3-4 times more often than in houses located at a distance of 50 m from the road. Transport also poisons water bodies, soil and plants.

Toxic emissions from internal combustion engines (ICE) are exhaust and crankcase gases, fuel vapors from the carburetor and fuel tank. The main share of toxic impurities enters the atmosphere with the exhaust gases of internal combustion engines. With crankcase gases and fuel vapors, approximately 45% of hydrocarbons from their total emission enter the atmosphere.

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

It is possible to exclude the entry of highly toxic lead compounds into the atmosphere by replacing leaded gasoline with unleaded.

The exhaust gases of gas turbine engines contain such toxic components as carbon monoxide, nitrogen oxides, hydrocarbons, soot, aldehydes, etc. The content of toxic components in combustion products significantly depends on the engine operating mode. High concentrations of carbon monoxide and hydrocarbons are typical for gas turbine propulsion systems (GTE) at reduced modes (during idling, taxiing, approaching the airport, landing approach), while the content of nitrogen oxides increases significantly when operating at modes close to nominal (takeoff , climb, flight mode).

The total emission of toxic substances into the atmosphere by aircraft with gas turbine engines is constantly growing, which is due to an increase in fuel consumption up to 20...30 t/h and a steady increase in the number of aircraft in operation. The influence of GTDU on the ozone layer and the accumulation of carbon dioxide in the atmosphere is noted.

GGDU emissions have the greatest impact on living conditions at airports and areas adjacent to test stations. Comparative data on emissions of harmful substances at airports suggest that the revenues from gas turbine engines into the surface layer of the atmosphere are, in%: carbon monoxide - 55, nitrogen oxides - 77, hydrocarbons - 93 and aerosol - 97. The rest of the emissions emit ground vehicles with internal combustion engines.

Air pollution by vehicles with rocket propulsion systems occurs mainly during their operation before launch, during takeoff, during ground tests during their production or after repair, during storage and transportation of fuel. The composition of combustion products during the operation of such engines is determined by the composition of the fuel components, the combustion temperature, and the processes of dissociation and recombination of molecules. The amount of combustion products depends on the power (thrust) of propulsion systems. During the combustion of solid fuels, water vapor, carbon dioxide, chlorine, hydrochloric acid vapor, carbon monoxide, nitrogen oxide, and Al2O3 solid particles with an average size of 0.1 microns (sometimes up to 10 microns) are emitted from the combustion chamber.

When launched, rocket engines adversely affect not only the surface layer of the atmosphere, but also outer space, destroying the Earth's ozone layer. The scale of the destruction of the ozone layer is determined by the number of launches of rocket systems and the intensity of flights of supersonic aircraft.

In connection with the development of aviation and rocket technology, as well as the intensive use of aircraft and rocket engines in other sectors of the national economy, the total emission of harmful impurities into the atmosphere has increased significantly. However, these engines still account for no more than 5% of toxic substances entering the atmosphere from vehicles of all types.

Atmospheric air is one of the main vital elements of the environment.

The Law “O6 for the Protection of Atmospheric Air” comprehensively covers the problem. He summarized the requirements developed in previous years and justified themselves in practice. For example, the introduction of rules prohibiting the commissioning of any production facilities (newly created or reconstructed) if they become sources of pollution or other negative impacts on the atmospheric air during operation. Got further development rules on the regulation of maximum permissible concentrations of pollutants in the atmospheric air.

The state sanitary legislation only for atmospheric air established MPCs for most chemicals with isolated action and for their combinations.

Hygienic standards are a state requirement for business leaders. Their implementation should be monitored by the bodies of state sanitary supervision of the Ministry of Health and State Committee on ecology.

Of great importance for the sanitary protection of atmospheric air is the identification of new sources of air pollution, the accounting of designed, under construction and reconstructed facilities that pollute the atmosphere, control over the development and implementation of master plans for cities, towns and industrial centers in terms of locating industrial enterprises and sanitary protection zones.

The Law "On the Protection of Atmospheric Air" provides for the requirements to establish standards for maximum permissible emissions of pollutants into the atmosphere. Such standards are established for each stationary source of pollution, for each model of vehicles and other mobile vehicles and installations. They are determined in such a way that the total harmful emissions from all sources of pollution in a given area do not exceed the MPC standards for pollutants in the air. Maximum allowable emissions are set only taking into account the maximum allowable concentrations.

The requirements of the Law relating to the use of plant protection products, mineral fertilizers and other preparations are very important. All legislative measures constitute a preventive system aimed at preventing air pollution.

The law provides not only control over the fulfillment of its requirements, but also responsibility for their violation. A special article defines the role of public organizations and citizens in the implementation of measures to protect the air environment, obliges them to actively promote government bodies in these matters, since only broad public participation will make it possible to implement the provisions of this law. Thus, it says that the state attaches great importance to the preservation of the favorable state of atmospheric air, its restoration and improvement in order to ensure the best living conditions for people - their work, life, recreation and health protection.

Enterprises or their individual buildings and structures, the technological processes of which are a source of the release of harmful and unpleasantly smelling substances into the atmospheric air, are separated from residential buildings by sanitary protection zones. The sanitary protection zone for enterprises and facilities can be increased, if necessary and properly justified, by no more than 3 times, depending on the following reasons: a) the effectiveness of the methods for cleaning emissions into the atmosphere provided or possible for implementation; b) lack of ways to clean emissions; c) placement of residential buildings, if necessary, on the leeward side in relation to the enterprise in the zone of possible air pollution; d) wind roses and other unfavorable local conditions (for example, frequent calms and fogs); e) construction of new, as yet insufficiently studied, sanitary hazardous industries.

Dimensions of sanitary protection zones for individual groups or complexes large enterprises chemical, oil refining, metallurgical, machine-building and other industries, as well as thermal power plants with emissions that create large concentrations of various harmful substances in the air and have a particularly adverse effect on the health and sanitary and hygienic living conditions of the population, are established in each case according to joint decision of the Ministry of Health and Gosstroy of Russia.

To increase the effectiveness of sanitary protection zones, trees, shrubs and herbaceous vegetation is planted on their territory, which reduces the concentration of industrial dust and gases. In the sanitary protection zones of enterprises that intensively pollute the atmospheric air with gases harmful to vegetation, the most gas-resistant trees, shrubs and grasses should be grown, taking into account the degree of aggressiveness and concentration of industrial emissions. Particularly harmful to vegetation are emissions from chemical industries (sulphurous and sulfuric anhydride, hydrogen sulfide, sulfuric, nitric, fluoric and bromous acids, chlorine, fluorine, ammonia, etc.), ferrous and non-ferrous metallurgy, coal and thermal power industries.

2. Hydrosphere

Water has always occupied and will continue to occupy a special position among natural resources Earth. This is the most important natural resource, since it is necessary, first of all, for the life of a person and every living being. Water is used by man not only in everyday life, but also in industry and agriculture.

The aquatic environment, which includes surface and groundwater, is called the hydrosphere. Surface water is mainly concentrated in the World Ocean, which contains about 91% of all water on Earth. The water in the ocean (94%) and underground is salty. The amount of fresh water is 6% of the total water on Earth, and a very small proportion of it is available in places that are easily accessible for extraction. Most of fresh water is contained in snow, freshwater icebergs and glaciers (1.7%), located mainly in the regions of the southern polar circle, as well as deep underground (4%).

Currently, humanity uses 3.8 thousand cubic meters. km. water annually, and consumption can be increased to a maximum of 12 thousand cubic meters. km. At the current rate of growth in water consumption, this will be enough for the next 25-30 years. deflating ground water leads to subsidence of soil and buildings and a decrease in groundwater levels by tens of meters.

Water is of great importance in industrial and agricultural production. It is well known that it is necessary for the everyday needs of man, all plants and animals. For many living beings, it serves as a habitat.

city ​​growth, rapid development industry, the intensification of agriculture, a significant expansion of the area of ​​irrigated land, the improvement of cultural and living conditions, and a number of other factors are increasingly complicating the problem of water supply.

Each inhabitant of the Earth on average consumes 650 cubic meters. m of water per year (1780 liters per day). However, to meet physiological needs, 2.5 liters per day is enough, i.e. about 1 cu. m per year. A large amount of water is required for agriculture (69%) mainly for irrigation; 23% of water is consumed by industry; 6% is spent in everyday life.

Taking into account the needs of water for industry and agriculture, water consumption in our country is from 125 to 350 liters per day per person (in St. Petersburg 450 liters, in Moscow - 400 liters).

In developed countries, each inhabitant has 200-300 liters of water per day. At the same time, 60% of the land does not have enough fresh water. A quarter of humanity (approximately 1.5 million people) lack it, and another 500 million suffer from lack and poor quality of drinking water, which leads to intestinal diseases.

Most of the water after its use for household needs is returned to the rivers in the form of wastewater.

Purpose of the work: to consider the main sources and types of pollution of the Hydrosphere, as well as methods of wastewater treatment.

Fresh water scarcity is already becoming a global problem. The ever-increasing needs of industry and agriculture for water are forcing all countries, scientists of the world to look for various means to solve this problem.

At the present stage, the following areas of rational use of water resources are determined: more complete use and expanded reproduction of fresh water resources; development of new technological processes to prevent pollution of water bodies and minimize the consumption of fresh water.

The structure of the Earth's hydrosphere

The hydrosphere is the water shell of the Earth. It includes: surface and groundwater, directly or indirectly providing the vital activity of living organisms, as well as water falling in the form of precipitation. Water occupies the predominant part of the biosphere. Out of 510 million km2 total area of the earth's surface, the World Ocean accounts for 361 million km2 (71%). The ocean is the main receiver and accumulator of solar energy, since water has a high thermal conductivity. The main physical properties of an aqueous medium are its density (800 times higher than air density) and viscosity (55 times higher than air). In addition, water is characterized by mobility in space, which helps to maintain the relative homogeneity of physical and chemical characteristics. Water bodies are characterized by temperature stratification, i.e. change in water temperature with depth. The temperature regime has significant daily, seasonal, annual fluctuations, but in general, the dynamics of water temperature fluctuations is less than that of air. The light regime of water under the surface is determined by its transparency (turbidity). The photosynthesis of bacteria, phytoplankton, and higher plants depends on these properties, and, consequently, the accumulation of organic matter, which is possible only within the euphonic zone, i.e. in the layer where the processes of synthesis prevail over the processes of respiration. Turbidity and transparency depend on the content of suspended substances of organic and mineral origin in water. Of the most significant for living organisms abiotic factors in water bodies, the salinity of water should be noted - the content of dissolved carbonates, sulfates, and chlorides in it. There are few of them in fresh waters, and carbonates predominate (up to 80%). In ocean water, chlorides and, to some extent, sulfates predominate. AT sea ​​water almost all elements of the periodic system, including metals, are dissolved. Another characteristic of the chemical properties of water is associated with the presence of dissolved oxygen and carbon dioxide in it. Oxygen, which goes to the respiration of aquatic organisms, is especially important. The vital activity and distribution of organisms in water depend on the concentration of hydrogen ions (pH). All the inhabitants of the water - hydrobionts have adapted to a certain level of pH: some prefer acidic, others - alkaline, others - neutral environment. A change in these characteristics, primarily as a result of industrial impact, leads to the death of aquatic organisms or to the replacement of some species by others.

The main types of pollution of the hydrosphere.

Pollution of water resources is understood as any changes in the physical, chemical and biological properties of water in reservoirs due to the discharge of liquid, solid and gaseous substances into them, which cause or may create inconvenience, making the water of these reservoirs dangerous for use, causing damage to the national economy, health and public safety. Sources of pollution are objects from which discharges or otherwise enter water bodies of harmful substances that degrade the quality of surface waters, limit their use, and also negatively affect the state of the bottom and coastal water bodies.

The main sources of pollution and clogging of water bodies are insufficiently treated wastewater from industrial and municipal enterprises, large livestock complexes, production waste from the development of ore minerals; water mines, mines, processing and alloying of timber; discharges of water and railway transport; flax primary processing waste, pesticides, etc. Pollutants entering natural water bodies lead to qualitative changes in water, which are mainly manifested in a change in the physical properties of water, in particular, the appearance unpleasant odors, flavors, etc.); in changing the chemical composition of water, in particular, the appearance of harmful substances in it, the presence of floating substances on the surface of the water and their deposition at the bottom of reservoirs.

Phenol is a rather harmful pollutant of industrial waters. It is found in the wastewater of many petrochemical plants. At the same time, the biological processes of reservoirs, the process of their self-purification, are sharply reduced, the water acquires a specific smell of carbolic acid.

The life of the population of reservoirs is adversely affected by wastewater from the pulp and paper industry. Oxidation of wood pulp is accompanied by the absorption of a significant amount of oxygen, which leads to the death of eggs, fry and adult fish. Fibers and others insoluble substances pollute the water and make it worse physiochemical properties. From rotting wood and bark, various tannins are released into the water. Resin and other extractive products decompose and absorb a lot of oxygen, causing the death of fish, especially juveniles and eggs. In addition, mole alloys heavily clog rivers, and driftwood often completely clogs their bottom, depriving fish of spawning grounds and food places.

Oil and oil products at the present stage are the main pollutants of inland waters, waters and seas, the World Ocean. Getting into water bodies, they create various forms of pollution: an oil film floating on the water, oil products dissolved or emulsified in water, heavy fractions that have settled to the bottom, etc. This hinders the processes of photosynthesis in water due to the cessation of access sun rays and also causes death of plants and animals. At the same time, the smell, taste, color, surface tension, viscosity of water change, the amount of oxygen decreases, harmful organic substances appear, water acquires toxic properties and poses a threat not only to humans. 12 g of oil makes a ton of water unfit for consumption. Each ton of oil creates an oil film on an area of ​​up to 12 square meters. km. Restoration of affected ecosystems takes 10-15 years.

Nuclear power plants radioactive waste pollute rivers. radioactive substances are concentrated by the smallest planktonic microorganisms and fish, then transmitted along the food chain to other animals. It has been established that the radioactivity of planktonic inhabitants is thousands of times higher than the water in which they live.

Wastewater with increased radioactivity (100 curies per 1 liter or more) is subject to disposal in underground drainless pools and special tanks.

Population growth, the expansion of old and the emergence of new cities have significantly increased the flow of domestic wastewater into inland waters. These effluents have become a source of pollution of rivers and lakes with pathogenic bacteria and helminths. Synthetic detergents widely used in everyday life pollute water bodies to an even greater extent. They are also widely used in industry and agriculture. The chemicals contained in them, entering rivers and lakes with sewage, have a significant impact on the biological and physical regime of water bodies. As a result, the ability of water to saturate with oxygen decreases, and the activity of bacteria that mineralize organic substances is paralyzed.

The pollution of water bodies with pesticides and mineral fertilizers, which come from the fields along with jets of rain and melt water, causes serious concern. As a result of research, for example, it has been proven that insecticides contained in water in the form of suspensions dissolve in oil products that pollute rivers and lakes. This interaction leads to a significant weakening of the oxidative functions of aquatic plants. Getting into water bodies, pesticides accumulate in plankton, benthos, fish, and through the food chain they enter the human body, affecting both individual organs and the body as a whole.

In connection with the intensification of animal husbandry, the effluents of enterprises in this branch of agriculture are increasingly making themselves felt.

Wastewater containing vegetable fibers, animal and vegetable fats, fecal matter, fruit and vegetable residues, waste from the leather and pulp and paper industries, sugar and breweries, meat and dairy, canning and confectionery industries are the cause organic pollution reservoirs.

Wastewater is usually about 60% of substances organic origin, the same category of organic includes biological (bacteria, viruses, fungi, algae) pollution in municipal, medical and sanitary waters and waste from leather and wool washing enterprises.

A serious environmental problem is that the usual way of using water to absorb heat in thermal power plants is to directly pump fresh lake or river water through a cooler and then return it to natural reservoirs without pre-cooling. A 1000 MW power plant requires a lake with an area of ​​810 hectares and a depth of about 8.7 m.

Power plants can raise the water temperature by 5-15 C compared to the environment. Under natural conditions, with slow increases or decreases in temperature, fish and others aquatic organisms gradually adapt to changes in ambient temperature. But if, as a result of the discharge of hot effluents from industrial enterprises into rivers and lakes, a new temperature regime is quickly established, there is not enough time for acclimatization, living organisms receive heat shock and die.

Heat shock is the extreme result of thermal pollution. The discharge of heated effluents into water bodies can have other, more insidious consequences. One of them is the effect on metabolic processes.

As a result of an increase in water temperature, the oxygen content in it decreases, while the need for it by living organisms increases. The increased need for oxygen, its lack cause severe physiological stress and even death. Artificial heating of water can significantly change the behavior of fish - cause untimely spawning, disrupt migration

An increase in water temperature can disrupt the structure of the flora of reservoirs. The algae characteristic of cold water are replaced by more thermophilic ones and, finally, with high temperatures are completely replaced by them, while favorable conditions arise for the mass development of blue-green algae in reservoirs - the so-called “water bloom”. All of the above effects of thermal pollution of water bodies cause great harm. natural ecosystems and lead to detrimental changes in the human environment. Damage resulting from thermal pollution can be divided into: - economic (losses due to a decrease in the productivity of water bodies, the cost of eliminating the consequences of pollution); social (aesthetic damage from landscape degradation); environmental (irreversible destruction of unique ecosystems, extinction of species, genetic damage).

The path that will allow people to avoid the ecological impasse is now clear. These are non-waste and low-waste technologies, the transformation of waste into useful resources. But it will take decades to bring the idea to life.

Wastewater Treatment Methods

Wastewater treatment is the treatment of wastewater to destroy or remove harmful substances from it. Cleaning methods can be divided into mechanical, chemical, physico-chemical and biological.

The essence of the mechanical method

purification consists in the fact that existing impurities are removed from wastewater by settling and filtering. Mechanical treatment allows you to isolate up to 60-75% of insoluble impurities from domestic wastewater, and up to 95% from industrial wastewater, many of which (as valuable materials) are used in production.

The chemical method consists in the fact that various chemical reagents are added to the wastewater, which react with pollutants and precipitate them in the form of insoluble precipitates. Chemical cleaning achieves a reduction of insoluble impurities up to 95% and soluble impurities up to 25%.

With the physicochemical method

Treatment of wastewater removes finely dispersed and dissolved inorganic impurities and destroys organic and poorly oxidized substances. Of the physicochemical methods, coagulation, oxidation, sorption, extraction, etc., as well as electrolysis, are most often used. Electrolysis is the destruction of organic matter in wastewater and the extraction of metals, acids and other inorganic substances by the flow of electric current. Wastewater treatment using electrolysis is effective in lead and copper plants, in the paint and varnish industry.

Wastewater is also treated using ultrasound, ozone, ion exchange resins and high pressure. Cleaning by chlorination has proven itself well.

Among the wastewater treatment methods, a biological method based on the use of the laws of biochemical self-purification of rivers and other water bodies should play an important role. Various types of biological devices are used: biofilters, biological ponds, etc. In biofilters, wastewater is passed through a layer of coarse-grained material covered with a thin bacterial film. Thanks to this film, the processes of biological oxidation proceed intensively.

In biological ponds, all organisms inhabiting the reservoir take part in wastewater treatment. Before biological treatment, wastewater is subjected to mechanical treatment, and after biological treatment (to remove pathogenic bacteria) and chemical cleaning, chlorination with liquid chlorine or bleach. For disinfection, other physical and chemical methods are also used (ultrasound, electrolysis, ozonation, etc.). biological method gives top scores when cleaning municipal waste, as well as waste from oil refining, pulp and paper industries, and the production of artificial fiber.

In order to reduce pollution of the hydrosphere, it is desirable to reuse in closed, resource-saving, waste-free processes in industry, drip irrigation in agriculture, and economical use of water in production and at home.

3. Lithosphere

The period from 1950 to the present is called the period of the scientific and technological revolution. By the end of the 20th century, there were huge changes in technology, new means of communication and information technologies appeared, which dramatically changed the possibilities for exchanging information and brought the most remote points of the planet closer together. The world is literally changing rapidly before our eyes, and humanity in its actions does not always keep pace with these changes.

Environmental problems did not arise on their own. This is the result of the natural development of civilization, in which the previously formulated rules for the behavior of people in their relationships with surrounding nature and within human society, which supported a stable existence, came into conflict with the new conditions created scientific and technological progress. In the new conditions, it is necessary to form both new rules of conduct and a new morality, taking into account all natural science knowledge. The greatest difficulty, which determines much in the decision environmental issues- still insufficient concern of human society as a whole and many of its leaders with the problems of preserving the environment.

Lithosphere, its structure

Man exists in a certain space, and the main component of this space is the earth's surface - the surface of the lithosphere.

The lithosphere is called the solid shell of the Earth, consisting of the earth's crust and the layer of the upper mantle underlying the earth's crust. The distance of the lower boundary of the Earth's crust from the Earth's surface varies within 5-70 km, and the Earth's mantle reaches a depth of 2900 km. After it, at a distance of 6371 km from the surface, there is a core.

Land occupies 29.2% of the surface of the globe. The upper layers of the lithosphere is called soil. The soil cover is the most important natural formation and a component of the Earth's biosphere. It is the soil shell that determines many processes occurring in the biosphere.

Soil is the main source of food, providing 95-97% of food resources for the world's population. Square land resources the world is 129 million square meters. km, or 86.5% of the land area. Arable land and perennial plantations in the composition of agricultural land occupy about 10% of the land, meadows and pastures - 25% of the land. Soil fertility and climatic conditions determine the possibility of existence and development ecological systems on the ground. Unfortunately, due to improper exploitation, some of the fertile land is lost every year. Thus, over the past century, as a result of accelerated erosion, 2 billion hectares of fertile land have been lost, which is 27% of the total area of ​​land used for agriculture.

Sources of soil pollution.

The lithosphere is polluted by liquid and solid pollutants and wastes. It has been established that annually one ton of waste is generated per inhabitant of the Earth, including more than 50 kg of polymeric, difficult to decompose.

Sources of soil pollution can be classified as follows.

Residential buildings and public utilities. The composition of pollutants in this category of sources is dominated by household waste, food waste, construction waste, waste from heating systems, worn-out household items, etc. All this is collected and taken to landfills. For large cities, the collection and destruction of household waste in landfills has become an intractable problem. The simple burning of garbage in city dumps is accompanied by the release of toxic substances. When burning such objects, for example, chlorine-containing polymers, highly toxic substances are formed - dioxides. Despite this, in recent years, methods have been developed for the destruction of household waste by incineration. A promising method is the burning of such debris over hot melts of metals.

Industrial enterprises. In solid and liquid industrial waste, there are constantly substances that can have toxic effect on living organisms and plants. For example, non-ferrous heavy metal salts are usually present in waste from the metallurgical industry. The engineering industry releases cyanides, arsenic and beryllium compounds into the environment; in the production of plastics and artificial fibers wastes containing phenol, benzene, styrene are formed; in the production of synthetic rubbers, catalyst wastes, substandard polymer clots get into the soil; during the production of rubber products, dust-like ingredients, soot, which settle on the soil and plants, waste rubber-textile and rubber parts, are released into the environment, and during the operation of tires, worn-out and failed tires, autotubes and rim tapes. The storage and disposal of used tires is currently unresolved issues, as this often causes strong fires that are very difficult to extinguish. The degree of utilization of used tires does not exceed 30% of their total volume.

Transport. During the operation of internal combustion engines, nitrogen oxides, lead, hydrocarbons, carbon monoxide, soot and other substances are intensively released, deposited on the surface of the earth or absorbed by plants. In the latter case, these substances also enter the soil and are involved in the cycle associated with food chains.

Agriculture. Soil pollution in agriculture occurs due to the introduction of huge amounts of mineral fertilizers and pesticides. Some pesticides are known to contain mercury.

Soil contamination with heavy metals. Heavy metals are non-ferrous metals whose density is more density gland. These include lead, copper, zinc, nickel, cadmium, cobalt, chromium, mercury.

A feature of heavy metals is that in small quantities, almost all of them are necessary for plants and living organisms. In the human body, heavy metals are involved in vital biochemical processes. However, exceeding the allowable amount leads to serious diseases.

...

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Let us examine in more detail the components of the biosphere.

Earth's crust - it is a solid shell transformed in the course of geological time, which makes up the upper part of the Earth's lithosphere. A number of minerals in the earth's crust (limestone, chalk, phosphorites, oil, coal, etc.) arose from the tissues of dead organisms. It is a paradoxical fact that relatively small living organisms could cause phenomena of a geological scale, which is explained by their highest ability to reproduce. For example, under favorable conditions, the cholera virion can create a mass of matter equal to the mass of the earth's crust in just 1.75 days! It can be assumed that in the biospheres of previous eras, colossal masses of living matter moved around the planet, forming reserves of oil, coal, etc. as a result of death.

The biosphere exists by repeatedly using the same atoms. At the same time, the share of 10 elements located in the first half of the periodic system (oxygen - 29.5%, sodium, magnesium - 12.7%, aluminum, silicon - 15.2%, sulfur, potassium, calcium, iron - 34.6 %) accounts for 99% of the entire mass of our planet (the mass of the Earth is 5976 * 10 21 kg), and 1% is accounted for by the rest of the elements. However, the significance of these elements is very great - they play an essential role in living matter.

IN AND. Vernadsky divided all the elements of the biosphere into 6 groups, each of which performs certain functions in the life of the biosphere. First group – inert gases (helium, krypton, neon, argon, xenon). Second group – precious metals (ruthenium, palladium, platinum, osmium, iridium, gold). In the earth's crust, the elements of these groups are chemically inactive, their mass is insignificant (4.4 * 10 -4% of the mass of the earth's crust), and participation in the formation of living matter is poorly studied. The third group - lanthanides (14 chemical elements - metals) make up 0.02% of the mass of the earth's crust and their role in the biosphere has not been studied. Fourth group – radioactive elements are the main source of formation of the internal heat of the Earth and affect the growth of living organisms (0.0015% of the mass of the earth's crust). Some elements fifth group - scattered elements (0.027% of the earth's crust) - play an essential role in the life of organisms (for example, iodine and bromine). the biggest sixth group constitute cyclic elements , which, having undergone a series of transformations in geochemical processes, return to their original chemical states. This group includes 13 light elements (hydrogen, carbon, nitrogen, oxygen, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, potassium, calcium) and one heavy element (iron).

biota It is the totality of all types of plants, animals and microorganisms. Biota is an active part of the biosphere, which determines all the most important chemical reactions, as a result of which the main gases of the biosphere (oxygen, nitrogen, carbon monoxide, methane) are created and quantitative relationships are established between them. Biota continuously forms biogenic minerals and maintains a constant chemical composition of ocean waters. Its mass is no more than 0.01% of the mass of the entire biosphere and is limited by the amount of carbon in the biosphere. The main biomass is made up of green land plants - about 97%, and the biomass of animals and microorganisms - 3%.

The biota is mainly composed of cyclic elements. Particularly important is the role of such elements as carbon, nitrogen and hydrogen, the percentage of which in biota is higher than in the earth's crust (60 times carbon, 10 times nitrogen and hydrogen). The figure shows a diagram of a closed carbon cycle. Only thanks to the circulation of the main elements in such cycles (primarily carbon), the existence of life on Earth is possible.

Pollution of the lithosphere. Life, the biosphere and the most important link in its mechanism - the soil cover, commonly called the earth - make up the uniqueness of our planet in the universe. And in the evolution of the biosphere, in the phenomena of life on Earth, the importance of the soil cover (land, shallow waters and shelf) as a special planetary shell has invariably increased.

The soil cover is the most important natural formation. Its role in the life of society is determined by the fact that the soil is the main source of food, providing 95-97% of the food resources for the world's population. A special property of the soil cover is its fertility , which is understood as a set of soil properties that ensure the yield of agricultural crops. The natural fertility of the soil is associated with the supply of nutrients in it and its water, air and thermal regimes. The soil provides the need for plants in water and nitrogen nutrition, being the most important agent of their photosynthetic activity. Soil fertility also depends on the amount of solar energy accumulated in it. The soil cover belongs to a self-regulating biological system, which is the most important part of the biosphere as a whole. Living organisms, plants and animals inhabiting the Earth fix solar energy in the form of phyto- or zoomass. The productivity of terrestrial ecosystems depends on the heat and water balance of the earth's surface, which determines the variety of forms of energy and matter exchange within the geographic envelope of the planet.

Particular attention should be paid to land resources. The area of ​​land resources in the world is 149 million km2, or 86.5% of the land area. Arable land and perennial plantations as part of agricultural land currently occupy about 15 million km 2 (10% of land), hayfields and pastures - 37.4 million km 2 (25%). The total area of ​​arable land is estimated by various researchers in different ways: from 25 to 32 million km 2. The planet's land resources make it possible to provide more people with food than is currently available and will be in the near future. However, due to population growth, especially in developing countries, the amount of arable land per capita is declining. Even 10-15 years ago, the mental security of the Earth's population with arable land was 0.45-0.5 hectares, at present it is already 0.35-37 hectares.

All usable material components of the lithosphere used in the economy as raw materials or energy sources are called mineral resources . Minerals can be ore if metals are extracted from it, and nonmetallic , if non-metallic components (phosphorus, etc.) are extracted from it or used as building materials.

If mineral wealth used as a fuel (coal, oil, gas, oil shale, peat, wood, nuclear energy) and at the same time as an energy source in engines to produce steam and electricity, they are called fuel and energy resources .

Hydrosphere . Water occupies the predominant part of the Earth's biosphere (71% of the earth's surface) and makes up about 4% of the mass of the earth's crust. Its average thickness is 3.8 km, average depth - 3554 m, area: 1350 million km 2 - oceans, 35 million km 2 - fresh water.

The mass of ocean water accounts for 97% of the mass of the entire hydrosphere (2 * 10 21 kg). The role of the ocean in the life of the biosphere is enormous: the main chemical reactions take place in it, which determine the production of biomass and chemical treatment biosphere. So, in 40 days, the surface five-hundred-meter layer of water in the ocean passes through the plankton filtration apparatus, therefore (taking into account mixing) all the oceanic water of the ocean undergoes purification during the year. All components of the hydrosphere (atmospheric water vapor, waters of the seas, rivers, lakes, glaciers, swamps, groundwater) are in constant motion and renewal.

Water is the basis of the biota (living matter is 70% water) and its importance in the life of the biosphere is decisive. The most important functions of water can be named as:

1. biomass production;

2. chemical purification of the biosphere;

3. ensuring carbon balance;

4. climate stabilization (water plays the role of a buffer in thermal processes on the planet).

The great importance of the world ocean lies in the fact that it produces almost half of the total oxygen in the atmosphere with its phytoplankton, i.e. is a kind of "lung" of the planet. At the same time, the plants and microorganisms of the ocean in the process of photosynthesis absorb annually a much larger part of carbon dioxide than plants on land absorb.

living organisms in the ocean – hydrobionates - are divided into three main ecological groups: plankton, nekton and benthos. Plankton - a set of passively floating and carried by sea currents of plants (phytoplankton), living organisms (zooplankton) and bacteria (bacterioplankton). Nekton - this is a group of actively swimming living organisms moving over considerable distances (fish, cetaceans, seals, sea snakes and turtles, octopus squids, etc.). Benthos - these are organisms that live on the seabed: sessile (corals, algae, sponges); burrowing (worms, mollusks); crawling (crustaceans, echinoderms); floating freely at the bottom. The coastal areas of the oceans and seas are the richest in benthos.

The oceans are a source of huge mineral resources. Already, oil, gas, 90% bromine, 60% magnesium, 30% salt, etc. are being extracted from it. The ocean has huge reserves of gold, platinum, phosphorites, oxides of iron and manganese, and other minerals. The level of mining in the ocean is constantly growing.

Pollution of the hydrosphere. In many regions of the world, the state of water bodies is of great concern. Pollution of water resources, not without reason, is now regarded as the most serious threat to the environment. The river network actually functions as the natural sewer system of modern civilization.

The most polluted are inland seas. They have a longer coastline and are therefore more prone to pollution. The accumulated experience of the struggle for the purity of the seas shows that this is an incomparably more difficult task than the protection of rivers and lakes.

The processes of water pollution are caused by various factors. The main ones are: 1) discharge of untreated wastewater into water bodies; 2) flushing of pesticides with heavy rainfall; 3) gas and smoke emissions; 4) leakage of oil and oil products.

The greatest harm to water bodies is caused by the release of untreated wastewater into them - industrial, municipal, collector-drainage, etc. Industrial wastewater pollutes ecosystems with various components, depending on the specifics of industries.

The level of pollution of the Russian seas (with the exception of White Sea), according to the State report "On the state of the environment of the Russian Federation", in 1998. exceeded the MPC for the content of hydrocarbons, heavy metals, mercury; surfactants (surfactants) on average 3-5 times.

The ingress of pollution to the ocean floor has a serious impact on the nature of biochemical processes. In this regard, the assessment of environmental safety in the planned extraction of minerals from the ocean floor, primarily iron-manganese nodules containing manganese, copper, cobalt and other valuable metals, is of particular importance. In the process of raking the bottom, the very possibility of life on the ocean floor will be destroyed for a long period, and the ingress of substances extracted from the bottom to the surface can adversely affect the air atmosphere of the region.

The huge volume of the World Ocean testifies to the inexhaustibility of the planet's natural resources. In addition, the World Ocean is a collector of land river waters, annually receiving about 39 thousand km 3 of water. The emerging pollution of the World Ocean threatens to disrupt the natural process of moisture circulation in its most critical link - evaporation from the surface of the ocean.

In the Water Code of the Russian Federation, the concept " water resources ” is defined as “reserves of surface and ground waters located in water bodies that are used or can be used” . Water is the most important component of the environment, a renewable, limited and vulnerable natural resource, used and protected in the Russian Federation as the basis of life and activity of the peoples living on its territory, ensures the economic, social, environmental well-being of the population, the existence of flora and fauna.

Any body of water or water source is associated with its external environment. It is influenced by the conditions for the formation of surface or underground water runoff, various natural phenomena, industry, industrial and municipal construction, transport, economic and domestic human activities. The consequence of these influences is the introduction of new, unusual substances into the aquatic environment - pollutants that degrade water quality. Pollution entering the aquatic environment is classified in different ways, depending on the approaches, criteria and tasks. So, usually allocate chemical, physical and biological pollution. Chemical pollution is a change in the natural chemical properties of water due to an increase in the content of harmful impurities in it, both inorganic (mineral salts, acids, alkalis, clay particles) and organic nature (oil and oil products, organic residues, surfactants, pesticides).

Despite the huge funds spent on the construction of treatment facilities, many rivers are still dirty, especially in urban areas. Pollution processes have even touched the oceans. And this does not seem surprising, since all caught in the rivers pollutants eventually rush to the ocean and reach it if they are difficult to decompose.

The environmental consequences of pollution of marine ecosystems are expressed in the following processes and phenomena:

violation of the stability of ecosystems;

progressive eutrophication;

the appearance of "red tides";

accumulation of chemical toxicants in biota;

decrease in biological productivity;

the occurrence of mutagenesis and carcinogenesis in the marine environment;

microbiological pollution of the coastal regions of the world.

Protecting the aquatic ecosystem is a complex and very important issue. To this end, the following environmental protection measures:

– development of waste-free and water-free technologies; introduction of water recycling systems;

– wastewater treatment (industrial, municipal, etc.);

– injection of sewage into deep aquifers;

– purification and disinfection of surface water used for water supply and other purposes.

The main pollutant of surface waters is sewage, so the development and implementation of effective wastewater treatment methods is a very urgent and environmentally important task. The most effective way to protect surface waters from pollution by sewage is the development and implementation of an anhydrous and waste-free production technology, the initial stage of which is the creation of a recycling water supply.

When organizing a recycling water supply system, it includes a number of treatment facilities and installations, which makes it possible to create a closed cycle for the use of industrial and domestic wastewater. With this method of water treatment, wastewater is always in circulation and their entry into surface water bodies is completely excluded.

Due to the huge variety of wastewater composition, there are various methods for their treatment: mechanical, physico-chemical, chemical, biological, etc. Depending on the degree of harmfulness and nature of pollution, wastewater treatment can be carried out by any one method or a set of methods (combined method). The treatment process involves the treatment of sludge (or excess biomass) and the disinfection of wastewater before being discharged into a reservoir.

In recent years, new effective methods have been actively developed that contribute to the environmental friendliness of wastewater treatment processes:

– electrochemical methods based on the processes of anodic oxidation and cathodic reduction, electrocoagulation and electroflotation;

– membrane purification processes (ultrafilters, electrodialysis, and others);

– magnetic treatment, which improves the flotation of suspended particles;

– radiation purification of water, which makes it possible to subject pollutants to oxidation, coagulation and decomposition in the shortest possible time;

- ozonation, in which wastewater does not form substances that adversely affect natural biochemical processes;

- introduction of new selective types for the selective separation of useful components from wastewater for the purpose of recycling, and others.

It is known that pesticides and fertilizers washed off by surface runoff from agricultural land play a role in the contamination of water bodies. To prevent the ingress of polluting effluents into water bodies, a set of measures is required, including:

compliance with the norms and terms of applying fertilizers and pesticides;

focal and tape treatment with pesticides instead of continuous;

application of fertilizers in the form of granules and, if possible, together with irrigation water;

replacement of pesticides by biological methods of plant protection.

Measures for the protection of waters and seas and the World Ocean are to eliminate the causes of deterioration in the quality and pollution of waters. Special measures to prevent pollution of sea water should be envisaged in the exploration and development of oil and gas fields on the continental shelves. It is necessary to introduce a ban on the dumping of toxic substances in the ocean and maintain a moratorium on nuclear weapons testing.

Atmosphere - the air environment around the Earth, its mass is about 5.15 * 10 18 kg. It has a layered structure and consists of several spheres, between which there are transitional layers - pauses. In the spheres, the amount of air and temperature change.

Depending on the distribution of temperature, the atmosphere is divided into:

– troposphere (its length in height in the middle latitudes is 10-12 km above sea level, at the poles - 7-10, above the equator - 16-18 km, more than 4/5 of the mass of the earth's atmosphere is concentrated here; due to the uneven heating of the earth's surface in powerful vertical air currents are formed in the troposphere, instability of temperature, relative humidity, pressure is noted, the air temperature in the troposphere decreases in height by 0.6 ° C for every 100 m and ranges from +40 to -50 ° C);

– stratosphere (has a length of about 40 km, the air in it is rarefied, the humidity is low, the air temperature is from -50 to 0 ° C at altitudes of about 50 km; in the stratosphere, under the influence of cosmic radiation and the short-wave part of the ultraviolet radiation of the sun, air molecules are ionized, resulting in the formation ozone layer located at an altitude of 25-40 km);

– mesosphere (from 0 to -90 o C at altitudes of 50-55 km);

– thermosphere (it is characterized by a continuous increase in temperature with increasing altitude - at an altitude of 200 km 500 ° C, and at an altitude of 500-600 km it exceeds 1500 ° C; gases are very rarefied in the thermosphere, their molecules move at high speed, but rarely collide with each other and therefore cannot cause even a slight heating of the body located here);

– exosphere (from several hundred km).

Uneven heating contributes to the general circulation of the atmosphere, which affects the weather and climate of the Earth.

The gas composition of the atmosphere is as follows: nitrogen (79.09%), oxygen (20.95%), argon (0.93%), carbon dioxide (0.03%) and a small amount of inert gases (helium, neon, krypton, xenon ), ammonia, methane, hydrogen, etc. . The lower layers of the atmosphere (20 km) contain water vapor, the amount of which decreases rapidly with height. At an altitude of 110-120 km, almost all oxygen becomes atomic. It is assumed that above 400-500 km and nitrogen is in the atomic state. The oxygen-nitrogen composition persists approximately up to an altitude of 400-600 km. The ozone layer, which protects living organisms from harmful short-wave radiation, is located at an altitude of 20-25 km. Above 100 km, the proportion of light gases increases, and at very high altitudes, helium and hydrogen predominate; part of the gas molecules break down into atoms and ions, forming ionosphere . Air pressure and density decrease with height.

Air pollution. The atmosphere has a huge impact on biological processes on land and in water bodies. The oxygen contained in it is used in the process of respiration of organisms and during the mineralization of organic matter, carbon dioxide is consumed during photosynthesis by autotrophic plants, and ozone reduces the ultraviolet radiation of the sun harmful to organisms. In addition, the atmosphere contributes to the preservation of the Earth's heat, regulates the climate, perceives gaseous metabolic products, transports water vapor around the planet, etc. Without an atmosphere, the existence of any complex organisms is impossible. Therefore, the issues of preventing air pollution have always been and remain relevant.

To assess the composition and pollution of the atmosphere, the concept of concentration (C, mg/m 3) is used.

Pure natural air has the following composition (in % vol): nitrogen 78.8%; oxygen 20.95%; argon 0.93%; CO 2 0.03%; other gases 0.01%. It is believed that such a composition should correspond to air at a height of 1 m above the ocean surface away from the coast.

As for all other components of the biosphere, there are two main sources of pollution for the atmosphere: natural and anthropogenic (artificial). The entire classification of pollution sources can be represented according to the above structural diagram: industry, transport, energy are the main sources of air pollution. According to the nature of the impact on the biosphere, atmospheric pollutants can be divided into 3 groups: 1) affecting global climate warming; 2) destroying biota; 3) destroying the ozone layer.

Let us note the brief characteristics of some atmospheric pollutants.

To pollutants first group should include CO 2, nitrous oxide, methane, freons. Into the creation greenhouse effect » The main contributor is carbon dioxide, which is increasing by 0.4% annually (for more on the greenhouse effect, see chapter 3.3). Compared with the middle of the XIX century, the content of CO 2 increased by 25%, nitrous oxide by 19%.

Freons - chemical compounds that are not characteristic of the atmosphere, used as refrigerants - are responsible for 25% of the creation of the greenhouse effect in the 90s. Calculations show that, despite the Montreal Agreement of 1987. on limiting the use of freons, by 2040. the concentration of the main freons will increase significantly (chlorofluorocarbon from 11 to 77%, chlorofluorocarbon - from 12 to 66%), which will lead to an increase in the greenhouse effect by 20%. The increase in the content of methane in the atmosphere was insignificant, but the specific contribution of this gas is about 25 times higher than that of carbon dioxide. If you do not stop the flow of "greenhouse" gases into the atmosphere, the average annual temperatures on Earth by the end of the 21st century will rise by an average of 2.5-5 ° C. It is necessary: ​​to reduce the burning of hydrocarbon fuels and deforestation. The latter is dangerous, in addition to leading to an increase in carbon in the atmosphere, it will also cause a decrease in the assimilating capacity of the biosphere.

To pollutants second group should include sulfur dioxide, suspended solids, ozone, carbon monoxide, nitric oxide, hydrocarbons. Of these substances in the gaseous state, sulfur dioxide and nitrogen oxides cause the greatest damage to the biosphere, which, in the course of chemical reactions, are converted into small crystals of sulfuric and nitric acid salts. The most acute problem is air pollution with sulfur-containing substances. Sulfur dioxide is harmful to plants. Entering the leaf during respiration, SO 2 inhibits the vital activity of cells. In this case, the leaves of the plants are first covered with brown spots, and then dry up.

Sulfur dioxide and its other compounds irritate the mucous membranes of the eyes and the respiratory tract. Long lasting low concentrations of SO 2 leads to chronic gastritis, hepatopathy, bronchitis, laryngitis and other diseases. There is evidence of a relationship between the content of SO 2 in the air and the death rate from lung cancer.

In the atmosphere, SO 2 is oxidized to SO 3. Oxidation occurs catalytically under the influence of trace metals, mainly manganese. In addition, SO 2 gaseous and dissolved in water can be oxidized with ozone or hydrogen peroxide. Combining with water, SO 3 forms sulfuric acid, which forms sulfates with the metals present in the atmosphere. The biological effect of acid sulfates at equal concentrations is more pronounced compared to SO 2 . Sulfur dioxide exists in the atmosphere from several hours to several days, depending on humidity and other conditions.

In general, aerosols of salts and acids penetrate into sensitive tissues of the lungs, devastate forests and lakes, reduce crops, destroy buildings, architectural and archaeological monuments. Suspended particulate matter poses a public health hazard that outweighs that of acid aerosols. Basically it's a danger big cities. Particularly harmful solids are found in the exhaust gases of diesel engines and two-stroke gasoline engines. Most particulate matter in the air of industrial origin in developed countries is successfully captured by all sorts of technical means.

Ozone in the surface layer appears as a result of the interaction of hydrocarbons formed during the incomplete combustion of fuel in automobile engines and released during many production processes, with nitrogen oxides. It is one of the most dangerous pollutants affecting the respiratory system. It is most intense in hot weather.

Carbon monoxide, nitrogen oxides and hydrocarbons mainly enter the atmosphere with vehicle exhaust gases. All of these chemical compounds have a devastating effect on ecosystems at concentrations even lower than those permissible for humans, namely: they acidify water basins, killing living organisms in them, destroy forests, and reduce crop yields (ozone is especially dangerous). Studies in the United States have shown that current concentrations of ozone reduce the yield of sorghum and corn by 1%, cotton and soybeans by 7%, and alfalfa by more than 30%.

Of the pollutants that destroy the stratospheric ozone layer, freons, nitrogen compounds, exhausts of supersonic aircraft and rockets should be noted.

Fluorochlorohydrocarbons, which are widely used as refrigerants, are considered the main source of chlorine in the atmosphere. They are used not only in refrigeration units, but also in numerous household aerosol cans with paints, varnishes, insecticides. Freon molecules are resistant and can be transported almost unchanged with atmospheric masses over great distances. At altitudes of 15–25 km (the zone of maximum ozone content), they are exposed to ultraviolet rays and decompose with the formation of atomic chlorine.

It has been established that over the past decade, the loss of the ozone layer amounted to 12–15% in the polar and 4–8% in the middle latitudes. In 1992, stunning results were established: areas with a loss of the ozone layer up to 45% were found at the latitude of Moscow. Already now, due to increased ultraviolet insolation, there is a decrease in yields in Australia and New Zealand, an increase in skin cancer.

Technogenic substances of the biosphere that have a harmful effect on biota are classified as follows (a general classification is given that is valid not only for gaseous substances). According to the degree of danger, all harmful substances are divided into four classes (Table 2):

I - extremely dangerous substances;

II - highly hazardous substances;

III - moderately hazardous substances;

IV - low-hazard substances.

The assignment of a harmful substance to a hazard class is carried out according to the indicator, the value of which corresponds to the highest hazard class.

Here: A) is a concentration that, during daily (except weekends) work for 8 hours, or another duration, but not more than 41 hours a week, during the entire working experience cannot cause diseases or deviations in the state of health detected by modern research methods in the course of work or in the remote periods of life of the present and subsequent generations;

B) - the dose of a substance that causes the death of 50% of animals with a single injection into the stomach;

C) - dose of a substance that causes the death of 50% of animals with a single application to the skin;

D) - the concentration of a substance in the air, causing the death of 50% of animals with a 2-4 hour inhalation exposure;

E) - the ratio of the maximum allowable concentration of a harmful substance in the air at 20 ° C to the average lethal concentration for mice;

E) - the ratio of the average lethal concentration of a harmful substance to the minimum (threshold) concentration that causes a change in biological indicators at the level of the whole organism, which go beyond the limits of adaptive physiological reactions;

G) - The ratio of the minimum (threshold) concentration that causes a change in biological parameters at the level of the whole organism, beyond the limits of adaptive physiological reactions, to the minimum (threshold) concentration that causes a harmful effect in a chronic experiment for 4 hours, 5 times a week for at least 4 -x months.

Table 2 Classification of harmful substances

Index	Norm for hazard class
(A) Maximum permissible concentration (MPC) of harmful substances in the air of the working area, mg / m 3
(B) Mean lethal dose when injected into the stomach (MAD), mg/kg				over 5000
(B) Mean lethal dose when applied to the skin (MTD), mg/kg				over 2500
(D) Mean lethal concentration in air (TLC), mg/m 3				over 50000
(E) Inhalation Poisoning Possibility Ratio (POI)
(E) Acute action zone (ZAZ)
(G) Chronic zone (ZZhA)	over 10.0

The danger of atmospheric pollutants for human health depends not only on their content in the air, but also on the hazard class. For a comparative assessment of the atmosphere of cities, regions, taking into account the hazard class of pollutants, the air pollution index is used.

Single and complex indices of air pollution can be calculated for different time intervals - for a month, a year. At the same time, the average monthly and average annual concentrations of pollutants are used in the calculations.

For those pollutants for which MPCs have not been established ( maximum allowable concentration ), is set estimated safe exposure levels (SHEETS). As a rule, this is explained by the fact that there is no experience gained in their use, sufficient to judge the long-term consequences of their impact on the population. If in technological processes substances are released and enter the air environment for which there are no approved MPCs or SHELs, enterprises are required to apply to the territorial bodies of the Ministry of Natural Resources to establish temporary standards. In addition, for some substances that pollute the air from time to time, only one-time MPCs have been established (for example, for formalin).

For some heavy metals, not only the average daily content in the atmospheric air (MPC ss) is normalized, but also the maximum allowable concentration during single measurements (MPC rz) in the air of the working area (for example, for lead - MPC ss \u003d 0.0003 mg / m 3, and MPC pz \u003d 0.01 mg / m 3).

Permissible concentrations of dusts and pesticides in the atmospheric air are also standardized. So, for dust containing silicon dioxide, the MPC depends on the content of free SiO 2 in it; when the content of SiO 2 changes from 70% to 10%, the MPC changes from 1 mg/m 3 to 4.0 mg/m 3 .

Some substances have a unidirectional harmful effect, which is called the summation effect (for example, acetone, acrolein, phthalic anhydride - group 1).

Anthropogenic atmospheric pollution can be characterized by the duration of their presence in the atmosphere, by the rate of increase in their content, by the scale of influence, by the nature of the influence.

The duration of the presence of the same substances is different in the troposphere and stratosphere. So, CO 2 is present in the troposphere for 4 years, and in the stratosphere - 2 years, ozone - 30-40 days in the troposphere, and 2 years in the stratosphere, and nitric oxide - 150 years (both there and there).

The rate of accumulation of pollution in the atmosphere is different (probably related to the utilization capacity of the biosphere). So the content of CO 2 increases by 0.4% per year, and nitrogen oxides - by 0.2% per year.

Basic principles of hygienic regulation of atmospheric pollutants.

The hygienic standardization of atmospheric pollution is based on the following criteria for the harmfulness of atmospheric pollution :

1. Only such concentration of a particular substance in the atmospheric air can be recognized as acceptable, which does not have a direct or indirect harmful and unpleasant effect on a person, does not reduce his working capacity, does not affect his well-being and mood.

2. Addiction to harmful substances should be considered as an unfavorable moment and proof of the inadmissibility of the studied concentration.

3. Such concentrations of harmful substances that adversely affect the vegetation, the climate of the area, the transparency of the atmosphere and the living conditions of the population are unacceptable.

The solution of the issue of the permissible content of atmospheric pollution is based on the idea of ​​the presence of thresholds in the action of pollution.

When scientifically substantiating the MPC of harmful substances in the atmospheric air, the principle of a limiting indicator is used (rationing according to the most sensitive indicator). So, if the smell is felt at concentrations that do not have a harmful effect on the human body and the environment, the rationing is carried out taking into account the threshold of smell. If a substance has a harmful effect on the environment in lower concentrations, then in the course of hygienic regulation, the threshold of action of this substance on the environment is taken into account.

For substances polluting the atmospheric air, two standards have been established in Russia: one-time and average daily MPC.

The maximum one-time MPC is set to prevent reflex reactions in humans (sense of smell, changes in the bioelectrical activity of the brain, light sensitivity of the eyes, etc.) with short-term (up to 20 minutes) exposure to atmospheric pollution, and the average daily one is set to prevent their resorptive (general toxic, mutagenic, carcinogenic, etc.) influences.

Thus, all components of the biosphere experience a colossal technogenic influence of man. At present, there is every reason to speak of the technosphere as a "sphere of unreason".

Questions for self-control

1. Group classification of elements of the biosphere V.I. Vernadsky.

2. What factors determine soil fertility?

3. What is the "hydrosphere"? Distribution and role of water in nature.

4. In what forms are harmful impurities present in wastewater, and how does this affect the choice of wastewater treatment methods?

5. Distinctive features of different layers of the atmosphere.

6. The concept of a harmful substance. Hazard classes of harmful substances.

7. What is MPC? Units of measurement of MPC in air and in water. Where are MPCs of harmful substances controlled?

8. How are the sources of emission and emissions of harmful substances into the atmosphere divided?

3.3 Circulation of substances in the biosphere . Biospheric carbon cycle. Greenhouse effect: the mechanism of occurrence and possible consequences.

The processes of photosynthesis of organic substances continue for hundreds of millions of years. But since the Earth is a finite physical body, any chemical elements are also physically finite. Over millions of years, they should, it would seem, be exhausted. However, this does not happen. Moreover, man constantly intensifies this process, increasing the productivity of the ecosystems he has created.

All substances on our planet are in the process of biochemical circulation of substances. There are 2 main circuits big or geological and small or chemical.

big circuit lasts for millions of years. It lies in the fact that rocks are destroyed, the products of destruction are carried away by water flows into the oceans or partially return to land along with precipitation. The processes of subsidence of the continents and the uplift of the seabed for a long time lead to the return of these substances to land. And the process starts again.

Small circuit , being part of a larger one, occurs at the ecosystem level and consists in the fact that soil nutrients, water, carbon are accumulated in plant matter and are spent on building the body and life processes. The decomposition products of the soil microflora decompose again to mineral components available to plants and are again involved in the flow of matter.

The circulation of chemicals from the inorganic environment through plants and animals back to inorganic environment using solar energy chemical reactions are called biochemical cycle .

The complex mechanism of evolution on Earth is determined by the chemical element "carbon". Carbon - an integral part of rocks and in the form of carbon dioxide is contained in part of the atmospheric air. Sources of CO2 are volcanoes, respiration, forest fires, fuel combustion, industry, etc.

The atmosphere intensively exchanges carbon dioxide with the world's oceans, where it is 60 times more than in the atmosphere, because. CO 2 is highly soluble in water (the lower the temperature, the higher the solubility, i.e. it is more in low latitudes). The ocean acts like a giant pump: it absorbs CO 2 in cold areas and partially "blows it out" in the tropics.

Excess carbon monoxide in the ocean combines with water to form carbonic acid. Combining with calcium, potassium, sodium, it forms stable compounds in the form of carbonates, which settle to the bottom.

Phytoplankton in the ocean absorb carbon dioxide during photosynthesis. Dead organisms fall to the bottom and become part of the sedimentary rocks. This shows the interaction of large and small circulation of substances.

Carbon from the CO 2 molecule during photosynthesis is included in the composition of glucose, and then in the composition of more complex compounds from which plants are built. Subsequently, they are transferred along food chains and form the tissues of all other living organisms in the ecosystem and are returned to the environment as part of CO 2 .

Carbon is also present in oil and coal. By burning fuel, a person also completes the cycle of carbon contained in the fuel - this is how biotechnical carbon cycle.

The remaining mass of carbon is found in carbonate deposits of the ocean floor (1.3-10t), in crystalline rocks (1-10t), in coal and oil (3.4-10t). This carbon takes part in the ecological cycle. Life on Earth and the gas balance of the atmosphere is maintained by a relatively small amount of carbon (5-10 tons).

There is a widespread opinion that global warming and its consequences threaten us due to industrial heat generation. That is, all the energy consumed in everyday life, industry and transport heats the Earth and the atmosphere. However, the simplest calculations show that the heating of the Earth by the Sun is many orders of magnitude higher than the results of human activity.

scientists probable cause Global warming is considered an increase in the concentration of carbon dioxide in the Earth's atmosphere. It is he who causes the so-called « greenhouse effect ».

What is Greenhouse effect ? We encounter this phenomenon very often. It is well known that at the same daytime temperature, the nighttime temperature is different, depending on the cloudiness. Cloudiness covers the earth like a blanket, and a cloudy night is 5-10 degrees warmer than a cloudless one at the same daytime temperature. However, if clouds, which are the smallest droplets of water, do not allow heat to pass both outside and from the Sun to the Earth, then carbon dioxide works like a diode - heat from the Sun comes to the Earth, but not back.

Mankind spends great amount natural resources, burns more and more fossil fuels, resulting in an increase in the percentage of carbon dioxide in the atmosphere, and it does not release infrared radiation from the heated surface of the Earth into space, creating a “greenhouse effect”. The consequence of a further increase in the concentration of carbon dioxide in the atmosphere may be global warming and an increase in the temperature of the Earth, which, in turn, will lead to such consequences as the melting of glaciers and the rise in the level of the world ocean by tens or even hundreds of meters, many coastal cities of the world.

This is a possible scenario for the development of events and the consequences of global warming, the cause of which is the greenhouse effect. However, even if all the glaciers of Antarctica and Greenland melt, the level of the world ocean will rise by a maximum of 60 meters. But this is an extreme, hypothetical case, which can only occur with the sudden melting of the glaciers of Antarctica. And for this, a positive temperature must be established in Antarctica, which can only be a consequence of a catastrophe on a planetary scale (for example, a change in the inclination of the earth's axis).

Among the supporters of the "greenhouse catastrophe" there is no unanimity about its likely scale, and the most authoritative of them do not promise anything terrible. The marginal warming, in the case of doubling the concentration of carbon dioxide, can be a maximum of 4°C. In addition, it is likely that with global warming and rising temperatures, the level of the ocean will not change, or even, on the contrary, will decrease. After all, with an increase in temperature, precipitation will also intensify, and the melting of the margins of glaciers can be compensated by increased snowfall in their central parts.

Thus, the problem of the greenhouse effect and the global warming it causes, as well as their possible consequences, although it exists objectively, the scale of these phenomena is clearly exaggerated today. In any case, they require very thorough research and long-term observation.

An international congress of climatologists, held in October 1985, was devoted to the analysis of the possible climatic consequences of the greenhouse effect. in Villach (Austria). The congress participants came to the conclusion that even a slight warming of the climate will lead to a noticeable increase in evaporation from the surface of the World Ocean, resulting in an increase in the amount of summer and winter precipitation over the continents. This increase will not be uniform. It is calculated that a strip will stretch across the south of Europe from Spain to Ukraine, within which the amount of precipitation will remain the same as now, or even slightly decrease. To the north of 50 ° (this is the latitude of Kharkov) both in Europe and in America it will gradually increase with fluctuations, which we have been observing over the past decade. Consequently, the flow of the Volga will increase, and the Caspian Sea is not threatened by a decrease in the level. This was the main scientific argument, which finally made it possible to abandon the project of transferring part of the flow of northern rivers to the Volga.

The most accurate, convincing data on the possible consequences of the greenhouse effect are provided by paleogeographic reconstructions compiled by specialists studying the geological history of the Earth over the past million years. After all, during this “recent” time of geological history, the climate of the Earth was subjected to very sharp global changes. In epochs colder than today, continental ice, like those that now hold down Antarctica and Greenland, covered all of Canada and the whole of northern Europe, including the places where Moscow and Kyiv now stand. Herds of reindeer and shaggy mammoths roamed the Crimean tundra and North Caucasus, there now find the remains of their skeletons. And during the interglacial epochs, the Earth's climate was much warmer than the current one: continental ice in North America and Europe they melted, in Siberia the permafrost thawed many meters, sea ice disappeared off our northern coasts, forest vegetation, judging by the fossil spore-pollen spectra, spread to the territory of modern tundra. Powerful river streams flowed across the plains of Central Asia, filling the basin of the Aral Sea with water up to a mark of plus 72 meters, many of them carried water to the Caspian Sea. The Karakum desert in Turkmenistan is the scattered sand deposits of these ancient channels.

In general, the physical-geographical situation during the warm interglacial epochs throughout the entire territory of the former USSR was more favorable than now. It was the same in the Scandinavian countries and the countries of Central Europe.

Unfortunately, until now, geologists studying the geological history of the last million years of the evolution of our planet have not been involved in the discussion of the problem of the greenhouse effect. And geologists could make valuable additions to existing ideas. In particular, it is obvious that for a correct assessment of the possible consequences of the greenhouse effect, paleographic data on past epochs of significant global climate warming should be more widely used. An analysis of such data, known today, allows us to think that the greenhouse effect, contrary to popular belief, does not bring any disasters for the peoples of our planet. On the contrary, in many countries, including Russia, it will create more favorable climatic conditions than now.

Questions for self-control

1. The essence of the main biochemical circulations of substances.

2. What is the biochemical carbon cycle?

3. What is meant by the term "greenhouse effect" and what is it associated with? Your brief assessment of the problem.

4. Do you think there is a threat of global warming? Justify your answer