How chemistry affects the environment or chemical pollution by industry
Introduction.
Consequences of an oil pipeline accident. 1996
At all stages of its development, man was closely connected with the outside world. But since the emergence of a highly industrial society, the dangerous human intervention in nature has increased dramatically, the scope of this interference has expanded, it has become more diverse and now threatens to become a global danger to humanity. The consumption of non-renewable raw materials is increasing, more and more arable land is leaving the economy, so cities and factories are being built on them. Man has to intervene more and more in the economy of the biosphere - that part of our planet in which life exists. The Earth's biosphere is currently subjected to increasing anthropogenic impact. At the same time, several of the most significant processes can be distinguished, none of which improves the ecological situation on the planet.
The most large-scale and significant is the chemical pollution of the environment by substances of a chemical nature unusual for it. Among them are gaseous and aerosol pollutants of industrial and household origin. The accumulation of carbon dioxide in the atmosphere is also progressing. Further development of this process will strengthen the undesirable trend towards an increase in the average annual temperature on the planet. Environmentalists are also alarmed by the ongoing pollution of the World Ocean with oil and oil products, which has already reached 1/5 of its total surface. Oil pollution of this size can cause significant disruption of gas and water exchange between the hydrosphere and the atmosphere. There is no doubt about the importance of chemical contamination of the soil with pesticides and its increased acidity, leading to the collapse of the ecosystem. In general, all the considered factors, which can be attributed to the polluting effect, have a significant impact on the processes occurring in the biosphere.
Chemical pollution of the biosphere.
Man has been polluting the atmosphere for thousands of years, but the consequences of the use of fire, which he used throughout this period, were insignificant. I had to put up with the fact that the smoke interfered with breathing, and that the soot lay in a black cover on the ceiling and walls of the dwelling. The resulting heat was more important for a person than clean air and unfinished cave walls. This initial air pollution was not a problem, for people then lived in small groups, occupying an immeasurably vast untouched natural environment. And even a significant concentration of people in a relatively small area, as was the case in classical antiquity, was not yet accompanied by serious consequences.
This was the case until the beginning of the nineteenth century. Only in the last hundred years has the development of industry "gifted" us with such production processes, the consequences of which at first man could not yet imagine. Million-strong cities arose, the growth of which cannot be stopped. All this is the result of great inventions and conquests of man.
Basically, there are three main sources of air pollution: industry, domestic boilers, transport. The share of each of these sources in total air pollution varies greatly from place to place. It is now generally accepted that industrial production pollutes the air the most. 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, which consume more than 70% of the annually produced solid and liquid fuels. The main harmful impurities of pyrogenic origin are the following:
Carbon monoxide. It is obtained by incomplete combustion of carbonaceous substances. It enters the air as a result of burning solid waste, with exhaust gases and emissions from industrial enterprises. At least 1250 million tons of this gas enters the atmosphere every year. Carbon monoxide is a compound that actively reacts with the constituent parts of the atmosphere and contributes to an increase in the temperature on the planet and the creation of a greenhouse effect.
Sulfur dioxide. It is emitted during the combustion of sulfur-containing fuel or the processing of sulfurous ores (up to 170 million tons per year). Part of the sulfur compounds is released during the combustion of organic residues in mining dumps. In the United States alone, the total amount of sulfur dioxide emitted into the atmosphere amounted to 65% of the global emission.
Sulfuric anhydride. It is formed during the oxidation of sulfur dioxide. The end product of the reaction is an aerosol or solution of sulfuric acid in rainwater, which acidifies the soil and exacerbates human respiratory diseases. The precipitation of sulfuric acid aerosol from smoke flares of chemical enterprises is observed at low cloudiness and high air humidity. The leaf blades of plants growing at a distance of less than 11 km from such enterprises are usually densely dotted with small necrotic spots formed at the sites of sedimentation of drops of sulfuric acid. Pyrometallurgical enterprises of non-ferrous and ferrous metallurgy, as well as thermal power plants annually emit tens of millions of tons of sulfuric anhydride into the atmosphere.
Hydrogen sulfide and carbon disulfide. They enter the atmosphere separately or together with other sulfur compounds. The main sources of emissions are enterprises for the manufacture of artificial fiber, sugar, coke, oil refineries, and oil fields. In the atmosphere, when interacting with other pollutants, they undergo slow oxidation to sulfuric anhydride.
nitrogen oxides. The main sources of emissions are enterprises producing nitrogen fertilizers, nitric acid and nitrates, aniline dyes, nitro compounds, viscose silk, and celluloid. The amount of nitrogen oxides entering the atmosphere is 20 million tons per year.
Fluorine compounds. Sources of pollution are enterprises producing aluminum, enamels, glass, ceramics, steel, and phosphate fertilizers. Fluorine-containing substances enter the atmosphere in the form of gaseous compounds - hydrogen fluoride or dust of sodium and calcium fluoride. The compounds are characterized by a toxic effect. Fluorine derivatives are strong insecticides.
Chlorine compounds. They enter the atmosphere from chemical enterprises producing hydrochloric acid, chlorine-containing pesticides, organic dyes, hydrolytic alcohol, bleach, soda. In the atmosphere, they are found as an admixture of chlorine molecules and hydrochloric acid vapors. The toxicity of chlorine is determined by the type of compounds and their concentration. In the metallurgical industry, during the smelting of pig iron and its processing into steel, various heavy metals and toxic gases are released into the atmosphere. Thus, per 1 tonne of saturated cast iron, in addition to 12.7 kg of sulfur dioxide and 14.5 kg of dust particles, which determine the amount of compounds of arsenic, phosphorus, antimony, lead, mercury vapor and rare metals, tar substances and hydrogen cyanide, are released.
INTRODUCTIONConsequences of an oil pipeline accident. 1996
At all stages of its development, man was closely connected with the outside world. But since the emergence of a highly industrialized society, the dangerous human intervention in nature has increased dramatically, the scope of this interference has expanded, it has become more diverse and now threatens to become a global danger to humanity. The consumption of non-renewable raw materials is increasing, more and more arable land is leaving the economy, so cities and factories are being built on them. Man has to intervene more and more in the economy of the biosphere - that part of our planet in which life exists. The Earth's biosphere is currently undergoing increasing anthropogenic impact. At the same time, several of the most significant processes can be distinguished, none of which improves the ecological situation on the planet.
The most large-scale and significant is the chemical pollution of the environment by substances of a chemical nature unusual for it. Among them are gaseous and aerosol pollutants of industrial and household origin. The accumulation of carbon dioxide in the atmosphere is also progressing. Further development of this process will strengthen the undesirable trend towards an increase in the average annual temperature on the planet. Environmentalists are also alarmed by the ongoing pollution of the World Ocean with oil and oil products, which has already reached 1/5 of its total surface. Oil pollution of this size can cause significant disruption of gas and water exchange between the hydrosphere and the atmosphere. There is no doubt about the importance of chemical contamination of the soil with pesticides and its increased acidity, leading to the collapse of the ecosystem. In general, all the considered factors, which can be attributed to the polluting effect, have a significant impact on the processes occurring in the biosphere.
CHEMICAL POLLUTION OF THE BIOSPHERE.
Man has been polluting the atmosphere for thousands of years, but the consequences of the use of fire, which he used throughout this period, were insignificant. I had to put up with the fact that the smoke interfered with breathing, and that the soot lay in a black cover on the ceiling and walls of the dwelling. The resulting heat was more important to a person than clean air and unfinished cave walls. This initial air pollution was not a problem, for people then lived in small groups, occupying an immeasurably vast untouched natural environment. And even a significant concentration of people in a relatively small area, as was the case in classical antiquity, was not yet accompanied by serious consequences.
This was the case until the beginning of the nineteenth century. Only in the last hundred years has the development of industry "gifted" us with such production processes, the consequences of which at first man could not yet imagine. Million-strong cities arose, the growth of which cannot be stopped. All this is the result of great inventions and conquests of man.
Basically, there are three main sources of air pollution: industry, domestic boilers, transport. The share of each of these sources in total air pollution varies greatly from place to place. It is now generally accepted that industrial production pollutes the air the most. 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, which consume more than 70% of the annually produced solid and liquid fuels. The main harmful impurities of pyrogenic origin are the following:
Carbon monoxide. It is obtained by incomplete combustion of carbonaceous substances. It enters the air as a result of burning solid waste, with exhaust gases and emissions from industrial enterprises. At least 1250 million tons of this gas enters the atmosphere every year. Carbon monoxide is a compound that actively reacts with the constituent parts of the atmosphere and contributes to an increase in the temperature on the planet and the creation of a greenhouse effect.
Sulfur dioxide. It is emitted during the combustion of sulfur-containing fuel or the processing of sulfurous ores (up to 170 million tons per year). Part of the sulfur compounds is released during the combustion of organic residues in mining dumps. In the United States alone, the total amount of sulfur dioxide emitted into the atmosphere amounted to 65% of the global emission.
Sulfuric anhydride . It is formed during the oxidation of sulfur dioxide. The end product of the reaction is an aerosol or solution of sulfuric acid in rainwater, which acidifies the soil and exacerbates human respiratory diseases. The precipitation of sulfuric acid aerosol from smoke flares of chemical enterprises is observed at low cloudiness and high air humidity. The leaf blades of plants growing at a distance of less than 11 km from such enterprises are usually densely dotted with small necrotic spots formed at the sites of sedimentation of drops of sulfuric acid. Pyrometallurgical enterprises of non-ferrous and ferrous metallurgy, as well as thermal power plants annually emit tens of millions of tons of sulfuric anhydride into the atmosphere.
Hydrogen sulfide and carbon disulfide. They enter the atmosphere separately or together with other sulfur compounds. The main sources of emissions are enterprises for the manufacture of artificial fiber, sugar, coke, oil refineries, and oil fields. In the atmosphere, when interacting with other pollutants, they undergo slow oxidation to sulfuric anhydride.
nitrogen oxides. The main sources of emissions are enterprises producing nitrogen fertilizers, nitric acid and nitrates, aniline dyes, nitro compounds, viscose silk, and celluloid. The amount of nitrogen oxides entering the atmosphere is 20 million tons per year.
Fluorine compounds. Sources of pollution are enterprises producing aluminum, enamels, glass, ceramics, steel, and phosphate fertilizers. Fluorine-containing substances enter the atmosphere in the form of gaseous compounds - hydrogen fluoride or dust of sodium and calcium fluoride. The compounds are characterized by a toxic effect. Fluorine derivatives are strong insecticides.
Chlorine compounds. They enter the atmosphere from chemical enterprises producing hydrochloric acid, chlorine-containing pesticides, organic dyes, hydrolytic alcohol, bleach, soda. In the atmosphere, they are found as an admixture of chlorine molecules and hydrochloric acid vapors. The toxicity of chlorine is determined by the type of compounds and their concentration. In the metallurgical industry, during the smelting of pig iron and its processing into steel, various heavy metals and toxic gases are released into the atmosphere. Thus, per 1 tonne of saturated cast iron, in addition to 12.7 kg of sulfur dioxide and 14.5 kg of dust particles, which determine the amount of compounds of arsenic, phosphorus, antimony, lead, mercury vapor and rare metals, tar substances and hydrogen cyanide, are released.
Aerosol pollution of the atmosphere. Aerosols are solid or liquid particles suspended in the air. The solid components of aerosols in some cases are especially dangerous for organisms, and cause specific diseases in humans. In the atmosphere, aerosol pollution is perceived in the form of smoke, fog, mist or haze. A significant part of aerosols is formed in the atmosphere when solid and liquid particles interact with each other or with water vapor. The average size of aerosol particles is 1-5 microns. About 1 cubic meter enters the Earth's atmosphere every year. km of dust particles of artificial origin. A large number of dust particles are also formed during the production activities of people. Information about some sources of technogenic dust is given in Table 1:
Table 1
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The main sources of artificial aerosol air pollution are thermal power plants that consume high-ash coal, enrichment plants, metallurgical, cement, magnesite and carbon black plants. Aerosol particles from these sources are distinguished by a wide variety of chemical composition. Most often, compounds of silicon, calcium and carbon are found in their composition, less often - oxides of metals: iron, magnesium, manganese, zinc, copper, nickel, lead, antimony, bismuth, selenium, arsenic, beryllium, cadmium, chromium, cobalt, molybdenum, as well as asbestos. An even greater variety is characteristic of organic dust, including aliphatic and aromatic hydrocarbons, acid salts. It is formed during the combustion of residual petroleum products, during the pyrolysis process at oil refineries, petrochemical and other similar enterprises. Permanent sources of aerosol pollution are industrial dumps - artificial mounds of redeposited material, mainly overburden, formed during mining or from waste from processing industries, thermal power plants. The source of dust and poisonous gases is mass blasting. So, as a result of one medium-sized explosion (250-300 tons of explosives), about 2 thousand cubic meters are released into the atmosphere. m of conditional carbon monoxide and more than 150 tons of dust. The production of cement and other building materials is also a source of air pollution with dust. The main technological processes of these industries - grinding and chemical processing of charges, semi-finished products and products obtained in hot gas streams are always accompanied by emissions of dust and other harmful substances into the atmosphere. Atmospheric pollutants include hydrocarbons - saturated and unsaturated, containing from 1 to 13 carbon atoms. They undergo various transformations, oxidation, polymerization, interacting with other atmospheric pollutants after being excited by solar radiation. As a result of these reactions, peroxide compounds, free radicals, compounds of hydrocarbons with oxides of nitrogen and sulfur are formed, often in the form of aerosol particles. Under certain weather conditions, especially large accumulations of harmful gaseous and aerosol impurities can form in the surface air layer.
This usually happens when there is an inversion in the air layer directly above the sources of gas and dust emission - the location of a layer of colder air under warm air, which prevents air masses and delays the transfer of impurities upward. As a result, harmful emissions are concentrated under the inversion layer, their content near the ground increases sharply, which becomes one of the reasons for the formation of a photochemical fog previously unknown in nature.
Photochemical fog (smog). Photochemical fog is a multicomponent mixture of gases and aerosol particles of primary and secondary origin. The composition of the main components of smog includes ozone, nitrogen and sulfur oxides, numerous organic peroxide compounds, collectively called photooxidants. Photochemical smog occurs as a result of photochemical reactions under certain conditions: the presence of a high concentration of nitrogen oxides, hydrocarbons and other pollutants in the atmosphere, intense solar radiation and calm or very weak air exchange in the surface layer with a powerful and increased inversion for at least a day. Sustained calm weather, usually accompanied by inversions, is necessary to create a high concentration of reactants.
Such conditions are created more often in June-September and less often in winter. In prolonged clear weather, solar radiation causes the breakdown of nitrogen dioxide molecules with the formation of nitric oxide and atomic oxygen. Atomic oxygen with molecular oxygen give ozone. It would seem that the latter, oxidizing nitric oxide, should again turn into molecular oxygen, and nitric oxide into dioxide. But that doesn't happen. The nitric oxide reacts with the olefins in the exhaust gases, which break down the double bond to form molecular fragments and excess ozone. As a result of the ongoing dissociation, new masses of nitrogen dioxide are split and give additional amounts of ozone. A cyclic reaction occurs, as a result of which ozone gradually accumulates in the atmosphere. This process stops at night. In turn, ozone reacts with olefins. Various peroxides are concentrated in the atmosphere, which in total form oxidants characteristic of photochemical fog. The latter are the source of the so-called free radicals, which are characterized by a special reactivity. Such smog is not uncommon over London, Paris, Los Angeles, New York and other cities in Europe and America. According to their physiological effects on the human body, they are extremely dangerous for the respiratory and circulatory systems and often cause premature death of urban residents with poor health.
The problem of controlling the emission of pollutants into the atmosphere by industrial enterprises (MPC). The priority in the development of maximum permissible concentrations in the air belongs to the USSR. MPC - such concentrations that a person and his offspring are directly or indirectly affected, do not worsen their performance, well-being, as well as sanitary and living conditions for people.
The generalization of all information on MPC, received by all departments, is carried out in the MGO (Main Geophysical Observatory). In order to determine air values based on the results of observations, the measured values of concentrations are compared with the maximum single maximum allowable concentration and the number of cases when the MPC was exceeded, as well as how many times the largest value was higher than the MPC, is determined. The average value of the concentration for a month or a year is compared with the long-term MPC - medium stable MPC. The state of air pollution by several substances observed in the atmosphere of the city is assessed using a complex indicator - the air pollution index (API). To do this, the MPC normalized to the corresponding values and the average concentrations of various substances with the help of simple calculations lead to the value of the concentrations of sulfur dioxide, and then summed up. The maximum one-time concentrations of the main pollutants were the highest in Norilsk (nitrogen and sulfur oxides), Frunze (dust), Omsk (carbon monoxide). The degree of air pollution by the main pollutants is in direct proportion to the industrial development of the city. The highest maximum concentrations are typical for cities with a population of more than 500 thousand inhabitants. Air pollution with specific substances depends on the type of industry developed in the city. If enterprises of several industries are located in a large city, then a very high level of air pollution is created, but the problem of reducing emissions of many specific substances still remains unresolved.
CHEMICAL POLLUTION OF NATURAL WATER.
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).
inorganic pollution. The main inorganic (mineral) pollutants of fresh and marine waters are a variety of chemical compounds that are toxic to the inhabitants of the aquatic environment. These are compounds of arsenic, lead, cadmium, mercury, chromium, copper, fluorine. Most of them end up in water as a result of human activities. Heavy metals are absorbed by phytoplankton and then transferred through the food chain to more highly organized organisms. The toxic effect of some of the most common pollutants in the hydrosphere is presented in Table 2:
table 2
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Degree of toxicity:
- - is absent
+ - very weak
++ - weak
+++ - strong
++++ - very strong.
In addition to the substances listed in the table, dangerous contaminants of the aquatic environment include inorganic acids and bases, which cause a wide range of pH of industrial effluents (1.0 - 11.0) and can change the pH of the aquatic environment to values of 5.0 or above 8.0, while fish in fresh and sea water can exist only in the pH range of 5.0 - 8.5. Among the main sources of pollution of the hydrosphere with minerals and biogenic elements, food industry enterprises and agriculture should be mentioned. About 6 million tons of salts are annually washed out from irrigated lands. By the year 2000 it is possible to increase their weight up to 12 million tons/year. Wastes containing mercury, lead, copper are localized in separate areas off the coast, but some of them are carried far beyond the territorial waters. Mercury pollution significantly reduces the primary production of marine ecosystems, inhibiting the development of phytoplankton. Wastes containing mercury usually accumulate in the bottom sediments of bays or river estuaries. Its further migration is accompanied by the accumulation of methyl mercury and its inclusion in the trophic chains of aquatic organisms. Thus, Minamata disease, first discovered by Japanese scientists in people who ate fish caught in the Minamata Bay, into which industrial effluents with technogenic mercury were uncontrollably discharged, became notorious.
organic pollution. Among the soluble substances introduced into the ocean from land, not only mineral and biogenic elements, but also organic residues are of great importance for the inhabitants of the aquatic environment. The removal of organic matter into the ocean is estimated at 300 - 380 million tons / year. Wastewater containing suspensions of organic origin or dissolved organic matter adversely affects the condition of water bodies. When settling, the suspensions flood the bottom and retard the development or completely stop the vital activity of these microorganisms involved in the process of water self-purification. When these sediments rot, harmful compounds and toxic substances, such as hydrogen sulfide, can be formed, which lead to pollution of all water in the river. The presence of suspensions also makes it difficult for light to penetrate deep into the water and slows down the processes of photosynthesis. One of the main sanitary requirements for water quality is the content of the required amount of oxygen in it. Harmful effect is exerted by all contaminants that in one way or another contribute to the reduction of oxygen content in water. Surfactants - fats, oils, lubricants - form a film on the surface of the water, which prevents gas exchange between water and the atmosphere, which reduces the degree of saturation of water with oxygen. A significant amount of organic matter, most of which is not characteristic of natural waters, is discharged into rivers along with industrial and domestic wastewater. Increasing pollution of water bodies and drains is observed in all industrial countries. Information on the content of some organic substances in industrial wastewater is provided in Table 3:
Table 3
Due to the rapid pace of urbanization and the somewhat slow construction of sewage treatment plants or their unsatisfactory operation, water basins and soil are polluted with household waste. Pollution is especially noticeable in slow-flowing or stagnant water bodies (reservoirs, lakes).
Decomposing in the aquatic environment, organic waste can become a medium for pathogenic organisms. Water contaminated with organic waste becomes almost unsuitable for drinking and other needs. Household waste is dangerous not only because it is a source of some human diseases (typhoid fever, dysentery, cholera), but also because it requires a lot of oxygen for its decomposition. If domestic wastewater enters the reservoir in very large quantities, then the content of soluble oxygen may drop below the level necessary for the life of marine and freshwater organisms.
THE PROBLEM OF POLLUTION OF THE WORLD OCEAN (on the example of a number of organic compounds).
Oil and oil products. Oil is a viscous oily liquid that is dark brown in color and has low fluorescence. Oil consists mainly of saturated aliphatic and hydroaromatic hydrocarbons. The main components of oil - hydrocarbons (up to 98%) - are divided into 4 classes:
Paraffins (alkenes) - (up to 90% of the total composition) - stable substances, the molecules of which are expressed by a straight and branched chain of carbon atoms. Light paraffins have maximum volatility and solubility in water.
Cycloparaffins - (30 - 60% of the total composition) - saturated cyclic compounds with 5-6 carbon atoms in the ring. In addition to cyclopentane and cyclohexane, bicyclic and polycyclic compounds of this group are found in oil. These compounds are very stable and difficult to biodegrade.
aromatic hydrocarbons - (20 - 40% of the total composition) - unsaturated cyclic compounds of the benzene series, containing 6 carbon atoms in the ring less than cycloparaffins. Oil contains volatile compounds with a molecule in the form of a single ring (benzene, toluene, xylene), then bicyclic (naphthalene), semicyclic (pyrene).
Olefins (alkenes) - (up to 10% of the total composition) - unsaturated non-cyclic compounds with one or two hydrogen atoms at each carbon atom in a molecule that has a straight or branched chain.
Oil and oil products are the most common pollutants in the oceans. By the beginning of the 1980s, about 6 million tons of oil were annually entering the ocean, which accounted for 0.23% of world production. The greatest losses of oil are associated with its transportation from production areas. Emergencies, discharge of washing and ballast water overboard by tankers - all this leads to the presence of permanent pollution fields along sea routes. In the period 1962-79, as a result of accidents, about 2 million tons of oil entered the marine environment. Over the past 30 years, since 1964, about 2,000 wells have been drilled in the World Ocean, of which 1,000 and 350 industrial wells have been equipped in the North Sea alone. Due to minor leaks, 0.1 million tons of oil are lost annually. Large masses of oil enter the seas along rivers, with domestic and storm drains.
The volume of pollution from this source is 2.0 million tons/year. Every year, 0.5 million tons of oil enters with industrial effluents. Getting into the marine environment, oil first spreads in the form of a film, forming layers of various thicknesses. By the color of the film, you can determine its thickness (Table 4):
Table 4
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The oil film changes the composition of the spectrum and the intensity of light penetration into the water. Light transmission of thin films of crude oil is 1-10% (280 nm), 60-70% (400 nm).
A film with a thickness of 30-40 microns completely absorbs infrared radiation. When mixed with water, oil forms an emulsion of two types: direct - "oil in water" - and reverse - "water in oil". Direct emulsions, composed of oil droplets with a diameter of up to 0.5 μm, are less stable and are typical for oils containing surfactants. When volatile fractions are removed, oil forms viscous inverse emulsions, which can remain on the surface, be carried by the current, wash ashore and settle to the bottom.
Pesticides. Pesticides are a group of man-made substances used to control pests and plant diseases. Pesticides are divided into the following groups: insecticides - to combat harmful insects, fungicides and bactericides - to combat bacterial plant diseases, herbicides - against weeds. It has been established that pesticides, destroying pests, harm many beneficial organisms and undermine the health of biocenoses. In agriculture, there has long been a problem of transition from chemical (polluting) to biological (environmentally friendly) methods of pest control. Currently, more than 5 million tons of pesticides enter the world market. About 1.5 million tons of these substances have already entered the terrestrial and marine ecosystems by ash and water. The industrial production of pesticides is accompanied by the appearance of a large number of by-products that pollute wastewater. In the aquatic environment, representatives of insecticides, fungicides and herbicides are more common than others. Synthesized insecticides are divided into three main groups: organochlorine, organophosphorus and carbonates. Organochlorine insecticides are obtained by chlorination of aromatic and heterocyclic liquid hydrocarbons. These include DDT and its derivatives, in the molecules of which the stability of aliphatic and aromatic groups in the joint presence increases, various chlorinated derivatives of chlorodiene (eldrin). These substances have a half-life of up to several decades and are very resistant to biodegradation. In the aquatic environment, polychlorinated biphenyls are often found - derivatives of DDT without an aliphatic part, numbering 210 homologues and isomers. Over the past 40 years, more than 1.2 million tons of polychlorinated biphenyls have been used in the production of plastics, dyes, transformers, and capacitors. Polychlorinated biphenyls (PCBs) enter the environment as a result of industrial wastewater discharges and the incineration of solid waste in landfills. The latter source delivers PBCs to the atmosphere, from where they fall out with atmospheric precipitation to all regions of the globe. Thus, in snow samples taken in Antarctica, the content of PBC was 0.03 - 1.2 kg/l.
Synthetic surfactants. Detergents (surfactants) belong to an extensive group of substances that lower the surface tension of water. They are part of synthetic detergents (SMC), widely used in everyday life and industry. Together with wastewater, surfactants enter the continental waters and the marine environment. SMS contain sodium polyphosphates, in which detergents are dissolved, as well as a number of additional ingredients that are toxic to aquatic organisms: flavoring agents, bleaching agents (persulphates, perborates), soda ash, carboxymethylcellulose, sodium silicates. Depending on the nature and structure of the hydrophilic part of the surfactant molecules, they are divided into anionic, cationic, amphoteric, and nonionic. The latter do not form ions in water. The most common among the surfactants are anionic substances. They account for more than 50% of all surfactants produced in the world. The presence of surfactants in industrial wastewater is associated with their use in such processes as the flotation concentration of ores, the separation of chemical technology products, the production of polymers, the improvement of conditions for drilling oil and gas wells, and the fight against equipment corrosion. In agriculture, surfactants are used as part of pesticides.
Compounds with carcinogenic properties. Carcinogenic substances are chemically homogeneous compounds that exhibit transforming activity and the ability to cause carcinogenic, teratogenic (violation of embryonic development processes) or mutagenic changes in organisms. Depending on the conditions of exposure, they can lead to growth inhibition, accelerated aging, disruption of individual development, and changes in the gene pool of organisms. Substances with carcinogenic properties include chlorinated aliphatic hydrocarbons, vinyl chloride, and especially polycyclic aromatic hydrocarbons (PAHs). The maximum amount of PAHs in the current sediments of the World Ocean (more than 100 µg/km of dry matter mass) was found in tentonically active zones subject to deep thermal action. The main anthropogenic sources of PAHs in the environment are the pyrolysis of organic substances during the combustion of various materials, wood, and fuel.
Heavy metals. Heavy metals (mercury, lead, cadmium, zinc, copper, arsenic) are common and highly toxic pollutants. They are widely used in various industrial productions, therefore, despite the treatment measures, the content of heavy metal compounds in industrial wastewater is quite high. Large masses of these compounds enter the ocean through the atmosphere. Mercury, lead and cadmium are the most dangerous for marine biocenoses. Mercury is transported to the ocean with continental runoff and through the atmosphere. During the weathering of sedimentary and igneous rocks, 3.5 thousand tons of mercury are released annually. The composition of atmospheric dust contains about 12 thousand tons of mercury, and a significant part is of anthropogenic origin. About half of the annual industrial production of this metal (910 thousand tons/year) ends up in the ocean in various ways. In areas polluted by industrial waters, the concentration of mercury in solution and suspension is greatly increased. At the same time, some bacteria convert chlorides into highly toxic methylmercury. Contamination of seafood has repeatedly led to mercury poisoning of the coastal population. By 1977, there were 2,800 victims of the Minomata disease, which was caused by waste from the production of vinyl chloride and acetaldehyde, which used mercury chloride as a catalyst. Insufficiently treated wastewater from enterprises entered the Minamata Bay. Pigs are a typical trace element found in all components of the environment: in rocks, soils, natural waters, the atmosphere, and living organisms. Finally, pigs are actively dispersed into the environment during human activities. These are emissions from industrial and domestic effluents, from smoke and dust from industrial enterprises, from exhaust gases from internal combustion engines. The migration flow of lead from the continent to the ocean goes not only with river runoff, but also through the atmosphere. With continental dust, the ocean receives (20-30) tons of lead per year.
Discharge of waste into the sea for the purpose of disposal (dumping). Many countries with access to the sea carry out marine burial of various materials and substances, in particular soil excavated during dredging, drill slag, industrial waste, construction waste, solid waste, explosives and chemicals, and radioactive waste. The volume of burials amounted to about 10% of the total mass of pollutants entering the World Ocean. The basis for dumping in the sea is the ability of the marine environment to process a large amount of organic and inorganic substances without much damage to the water. However, this ability is not unlimited.
Therefore, dumping is considered as a forced measure, a temporary tribute to the imperfection of technology by society. Industrial slags contain a variety of organic substances and heavy metal compounds. Household waste contains on average (by weight of dry matter) 32-40% organic matter; 0.56% nitrogen; 0.44% phosphorus; 0.155% zinc; 0.085% lead; 0.001% mercury; 0.001% cadmium. During the discharge, the passage of the material through the water column, part of the pollutants goes into solution, changing the quality of the water, the other is sorbed by suspended particles and goes into bottom sediments. At the same time, the turbidity of the water increases. The presence of organic substances often leads to the rapid consumption of oxygen in water and often to its complete disappearance, the dissolution of suspensions, the accumulation of metals in dissolved form, and the appearance of hydrogen sulfide.
The presence of a large amount of organic matter creates a stable reducing environment in the soil, in which a special type of interstitial water appears, containing hydrogen sulfide, ammonia, and metal ions. Benthic organisms and others are affected to varying degrees by the discharged materials. In the case of the formation of surface films containing petroleum hydrocarbons and surfactants, gas exchange at the air-water interface is disrupted. Pollutants entering the solution can accumulate in the tissues and organs of hydrobiants and have a toxic effect on them. The dumping of dumping materials to the bottom and prolonged increased turbidity of the given water leads to the death of inactive forms of benthos from suffocation. In surviving fish, mollusks and crustaceans, the growth rate is reduced due to the deterioration of feeding and breathing conditions. The species composition of a given community often changes. When organizing a system of control over the discharge of waste into the sea, the definition of dumping areas, the determination of the dynamics of pollution of sea water and bottom sediments is of decisive importance. To identify possible volumes of discharge into the sea, it is necessary to carry out calculations of all pollutants in the composition of the material discharge.
thermal pollution. Thermal pollution of the surface of reservoirs and coastal marine areas occurs as a result of the discharge of heated wastewater from power plants and some industrial production. The discharge of heated water in many cases causes an increase in water temperature in reservoirs by 6-8 degrees Celsius. The area of heated water spots in coastal areas can reach 30 square meters. km. A more stable temperature stratification prevents water exchange between the surface and bottom layers. The solubility of oxygen decreases, and its consumption increases, since with increasing temperature, the activity of aerobic bacteria that decompose organic matter increases. The species diversity of phytoplankton and the entire flora of algae is increasing.
Based on the generalization of the material, it can be concluded that the effects of anthropogenic impact on the aquatic environment are manifested at the individual and population-biocenotic levels, and the long-term effect of pollutants leads to a simplification of the ecosystem.
SOIL POLLUTION.
The soil cover of the Earth is the most important component of the Earth's biosphere. It is the soil shell that determines many processes occurring in the biosphere.
The most important significance of soils is the accumulation of organic matter, various chemical elements, and energy. The soil cover functions as a biological absorber, destroyer and neutralizer of various contaminants. If this link of the biosphere is destroyed, then the existing functioning of the biosphere will be irreversibly disrupted. That is why it is extremely important to study the global biochemical significance of the soil cover, its current state and changes under the influence of anthropogenic activity. One of the types of anthropogenic impact is pesticide pollution.
Pesticides as a polluting factor. The discovery of pesticides - chemical means of protecting plants and animals from various pests and diseases - is one of the most important achievements of modern science. Today in the world 300 kg of chemicals are applied per 1 hectare. However, as a result of long-term use of pesticides in agriculture and medicine (vector control), there is almost universally a decline in effectiveness due to the development of resistant pest strains and the spread of "new" pests whose natural enemies and competitors have been destroyed by pesticides. At the same time, the effect of pesticides began to manifest itself on a global scale. Of the huge number of insects, only 0.3% or 5 thousand species are harmful. Pesticide resistance has been found in 250 species. This is exacerbated by the phenomenon of cross-resistance, which consists in the fact that increased resistance to the action of one drug is accompanied by resistance to compounds of other classes. From a general biological point of view, resistance can be considered as a change in populations as a result of the transition from a sensitive strain to a resistant strain of the same species due to selection caused by pesticides. This phenomenon is associated with genetic, physiological and biochemical rearrangements of organisms. Excessive use of pesticides (herbicides, insecticides, defoliants) negatively affects soil quality. In this regard, the fate of pesticides in soils and the possibilities and possibilities of neutralizing them by chemical and biological methods are being intensively studied. It is very important to create and use only drugs with a short lifespan, measured in weeks or months. Some progress has already been made in this area and drugs with a high rate of destruction are being introduced, but the problem as a whole has not yet been resolved.
Acidic atmospheric impacts on land. One of the most acute global problems of today and the foreseeable future is the problem of increasing acidity of precipitation and soil cover. Areas of acidic soils do not know droughts, but their natural fertility is lowered and unstable; they are rapidly depleted and yields are low. Acid rain causes not only acidification of surface waters and upper soil horizons. Acidity with downward water flows extends to the entire soil profile and causes significant acidification of groundwater. Acid rain occurs as a result of human economic activity, accompanied by the emission of colossal amounts of oxides of sulfur, nitrogen, and carbon. These oxides, entering the atmosphere, are transported over long distances, interact with water and turn into solutions of a mixture of sulfurous, sulfuric, nitrous, nitric and carbonic acids, which fall in the form of "acid rain" on land, interacting with plants, soils, waters. The main sources in the atmosphere are the burning of shale, oil, coal, gas in industry, agriculture, and at home. Human economic activity has almost doubled the entry of sulfur oxides, nitrogen, hydrogen sulfide and carbon monoxide into the atmosphere. Naturally, this affected the increase in the acidity of atmospheric precipitation, ground and ground waters. To solve this problem, it is necessary to increase the volume of systematic representative measurements of atmospheric pollutant compounds over large areas.
CONCLUSION.
The protection of nature is the task of our century, a problem that has become a social one. Again and again we hear about the danger threatening the environment, but still many of us consider them an unpleasant, but inevitable product of civilization and believe that we will still have time to cope with all the difficulties that have come to light.
However, human impact on the environment has taken on alarming proportions. To fundamentally improve the situation, purposeful and thoughtful actions will be needed. A responsible and efficient policy towards the environment will be possible only if we accumulate reliable data on the current state of the environment, substantiated knowledge about the interaction of important environmental factors, if we develop new methods to reduce and prevent the harm caused to Nature by Man.
Impact of chemical production on the environment
Chemical production has a manifold impact on the environment. In general, three types of impact can be distinguished:
- pollution of the natural environment with chemicals,
- depletion of natural resources;
- change in natural and the emergence of anthropogenic (technogenic) landscapes.
In fact, all these three types of interaction are interrelated and can only be separated in extreme cases. Let's consider these effects in more detail.
Pollution of the natural environment with chemicals as a result of the work of a chemical enterprise is more correctly associated with the uncontrolled flow of waste from this production into the natural environment. In this case, waste should include all emissions, discharges, losses of main and auxiliary products, etc. Apparently, it is more correct to use the term pollutant, which means any chemical product that enters the environment or occurs in it in quantities that go beyond the limits of the usual content, limiting natural fluctuations, or the average natural background at the time in question.
So, in dust emissions from the Petrochemia plant in Plock (Poland), the content of aluminum is 69.3, vanadium - 22.4, iron - 9.0, nickel - 2.58, heavy metals (lead, chromium, cobalt, molybdenum, cadmium, etc.) - 0.43% (May). Around the plant on an area of about 150 square meters. km annually falls 924 tons of vanadium compounds, 105 tons of nickel, 37 tons of lead, 765 tons of iron and about 70 tons of compounds of other metals. The accumulation of heavy metals in plants is 2...3 times higher than in areas more distant from the plant (data from 1986).
Chemical enterprises are sources of pollution not only of the air environment, but also of water bodies with sewage. Thus, the production of mineral and inorganic salts produces wastewater containing inorganic acids, alkalis, salts: fluorides, sulfates, phosphates, etc.
Production of the main organic and petrochemical synthesis contain fatty acids, aromatic compounds, alcohols in discharged wastewater (discharges).
Oil refineries and enterprises for the thermal processing of solid fuels discharge oil products, oils and resins, phenols, surfactants, etc. together with wastewater. The production of synthetic resins, polymers, synthetic fibers contain macromolecular substances, monomers, polymer particles, etc. .d.
Solid wastes from chemical industries, when uncontrolled release into the environment, also cause its pollution.
Not only chemical production wastes pose a danger to the environment, but also their products when they enter the natural environment uncontrollably. The latter circumstance is due to the toxicity of chemical products.
Indeed, a compound from the group of nitrosamines synthesized, for example, in Oak Ridges, causes mutations in mice 5 times greater than their irradiation with a dose of 600 rads. It is clear that the entry of such a substance into the natural environment dramatically increases the risk of mutations in living organisms.
Depletion of natural resources is the second type of impact of chemical (chemical-metallurgical) production on the environment. An illustration of this is the idea of an integral resource proposed by academicians N.P. Fedorsenko and N.F. Rsimmsrs (Fig. 3.5).
Rice. 3.5. Scheme illustrating the deterioration of the quality of natural resources (integral resource) as a result of technogenic impact:
a - the initial level of groundwater; 6 - groundwater level as a result of economic activity; 1 - deforestation; 2 - relief destruction; 3 - death of fish; 4 - siltation of the reservoir; 5 - lowering of the river level; 6 - reduction in electricity generation at hydroelectric power plants as a result of a decrease in the level of the river: 7 - deforestation as a result of atmospheric pollution
The peculiarity of an integral resource is that a qualitative or quantitative change in one of the components of an integral resource inevitably leads to more or less noticeable changes in the quantity and quality of other components of this resource.
Thus, the construction of a chemical plant and the exploitation of certain specific raw materials by it is accompanied by a deterioration in the quality of natural resources, their depletion and environmental pollution.
The change in natural landscapes and the emergence of anthropogenic ones directly follows from the further development of the concept of an integral resource. The deterioration in the value of natural resources (in particular, aesthetic and recreational ones) necessarily accompanies the transformation of natural landscapes into anthropogenic (technogenic) ones.
The classification of natural-technogenic landscapes is given in fig. 3.6.
Rice. 3.6. Classification of natural-technogenic landscapes
Anthropogenic landscape - a landscape, the emergence and structure of which are determined by human activity; It is subdivided into two types: cultural (first) and acultural (second).
Cultural is the result of purposeful human activity, it is constantly maintained by a person in the right state to perform certain tasks (such landscapes include cultivated fields, parks, gardens, etc.).
The second type of landscape - acultural - is not directly created and is often the result of undesirable natural processes caused by human activity: the development of ravines in the fields is most often the result of a violation of agricultural technology; swamping of the banks of reservoirs of lowland rivers occurs as a result of a sharp slowdown in the flow of water and a rise in the level of groundwater; the formation of sinkholes and soil subsidence is often associated with collapses of underground voids resulting from underground mining, etc.
Purpose of the study: To study the influence of industry on the nature of the planet. Tasks: 1. Describe the interaction of industrial enterprises with the environment; 2. Show the environmental impact of environmental pollution; 3. Form a common ecological culture of a person.
At all stages of its development, man was closely connected with the outside world. But since the emergence of a highly industrial society, the dangerous interference of man in nature has increased dramatically. Man has to intervene more and more in the economy of the biosphere - that part of our planet in which life exists. Nowadays, there are several sources of environmental pollution. One of them is industry.
It is known that atmospheric pollution occurs mainly as a result of the work of industry, transport, etc., which together annually emit more than a billion solid and gaseous particles “to the wind”. The main air pollutants today are carbon monoxide and sulfur dioxide. It is now generally accepted that industrial production pollutes the air the most. 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. The most common atmospheric pollutants enter it mainly in two forms: either in the form of suspended particles or in the form of gases. Air pollution
Water pollution Mankind uses mainly fresh water for its needs. Their volume is slightly more than 2% of the hydrosphere, and the distribution of water resources across the globe is extremely uneven. In Europe and Asia, where 70% of the world's population lives, only 39% of river waters are concentrated. The total consumption of river waters is increasing from year to year in all regions of the world. The lack of water is exacerbated by the deterioration of its quality. The waters used in industry, agriculture and everyday life are returned to water bodies in the form of poorly treated or generally untreated effluents. Thus, pollution of the hydrosphere occurs primarily as a result of the discharge of industrial, agricultural and domestic wastewater into rivers, lakes and seas. At present, many rivers are highly polluted - the Danube, Volga, Dnieper, Dniester, etc. Pollution of the World Ocean is growing. And here a significant role is played not only by sewage pollution, but also by the ingress of a large amount of oil products into the waters of the seas and oceans. One of the main sanitary requirements for water quality is the content of the required amount of oxygen in it. Harmful effects have all the pollution, which, one way or another, contribute to the reduction of oxygen in the water. Increasing pollution of water bodies and drains is observed in all industrial countries.
Soil pollution The soil cover of the Earth is the most important component of the Earth's biosphere. It is the soil shell that determines many processes occurring in the biosphere. Soil pollution is difficult to classify; in different sources, their division is given in different ways. If we generalize and highlight the main thing, then the following picture of soil pollution is observed: garbage, emissions, dumps, sedimentary rocks; heavy metals; pesticides; radioactive substances. The most important significance of soils is the accumulation of organic matter, various chemical elements, and energy. The soil cover functions as a biological absorber, destroyer and neutralizer of various contaminants. If this link of the biosphere is destroyed, then the existing functioning of the biosphere will be irreversibly disrupted. That is why it is extremely important to study the global biochemical significance of the soil cover, its current state and changes under the influence of anthropogenic activity. One of the types of anthropogenic impact is pesticide pollution. Almost all pollutants that are initially released into the atmosphere end up on land and water. Settling aerosols may contain toxic heavy metals - lead, mercury, copper, vanadium, cobalt, nickel. Usually they are inactive and accumulate in the soil. But acids also get into the soil with rain. By combining with it, metals can turn into soluble compounds available to plants. Substances that are constantly present in the soil also pass into soluble forms, which sometimes leads to the death of plants.
The problem of acid residues One of the most acute global problems of today and the future is the problem of increasing acidity of precipitation and soil cover. Every year, about 200 million solid particles (dust, soot, etc.), 200 million tons of sulfur dioxide (SO2), 700 million tons of sulfur dioxide are released into the Earth's atmosphere. tons of carbon monoxide, 150 mln. tons of nitrogen oxides, which in total is more than 1 billion tons of harmful substances. Acid rain (or, more correctly), acid precipitation, since the fallout of harmful substances can occur both in the form of rain and in the form of snow, hail, cause tremendous damage. As a result of acid precipitation, the balance in ecosystems is disturbed. Areas of acidic soils do not know droughts, but their natural fertility is reduced and unstable; they are quickly depleted and their yields are low; metal structures rust; buildings, structures, etc. are destroyed. Acid rain causes not only acidification of surface waters and upper soil horizons. Acidity with downward water flows extends to the entire soil profile and causes significant acidification of groundwater. Acid rain occurs as a result of human activities, accompanied by the emission of colossal amounts of oxides of sulfur, nitrogen, carbon. These oxides, entering the atmosphere, are transported over long distances, interact with water and turn into solutions of a mixture of sulfurous, sulfuric, nitrous, nitric and carbonic acids, which fall in the form of acid rain on land, interacting with plants, soils, waters. One of the causes of forest death in many regions of the world is acid rain. To solve this problem, it is necessary to increase the volume of systematic measurements of atmospheric pollutant compounds over large areas.
The problem of the greenhouse effect Until the middle of the XX century. climate fluctuations depended relatively little on man and his economic activity. Over the past decades, this situation has changed quite dramatically. As a result of anthropogenic activity, the amount of carbon dioxide in the atmosphere is steadily increasing, which leads to an increase in the greenhouse effect and contributes to an increase in air temperature near the earth's surface. The change in the average air temperature is directly related to the change in the area of snow and ice covers. The ice regime depends on the arrival of solar radiation, air temperature in the warm and cold seasons. According to experts, the active melting of the Arctic sea ice will begin with an increase in the average air temperature in the Northern Hemisphere by about 2°C. Climate change affects precipitation patterns. Warming leads to an increase in evaporation from the surface of the oceans and, consequently, to an increase in the amount of precipitation that falls on the earth's surface. Climate change inevitably affects the level of the World Ocean. It has been suggested that the western part of the Antarctic ice sheet is unstable and could collapse (with rapid warming) within a few decades, which would raise the ocean level by about 5 m and lead to the flooding of large areas of the earth's surface.
The problem of the ozone layer The ecological problem of the ozone layer is no less complex in scientific terms. As you know, life on Earth appeared only after the protective ozone layer of the planet was formed, covering it from cruel ultraviolet radiation. The problem of the ozone layer arose in 1982, when a probe launched from a British station in Antarctica detected a sharp decrease in ozone at an altitude of kilometers. Since then, an ozone "hole" of varying shapes and sizes has been recorded over Antarctica all the time. According to the latest data for 1992, it is equal to 23 million square kilometers, that is, an area equal to the whole of North America. Later, the same "hole" was discovered over the Canadian Arctic Archipelago, over Svalbard, and then in different places of Eurasia, in particular over Voronezh. The depletion of the ozone layer is a much more dangerous reality for all life on Earth than the fall of some super-large meteorite, because ozone does not allow dangerous radiation to reach the Earth's surface. In the event of a decrease in ozone, humanity is threatened, at a minimum, with an outbreak of skin cancer and eye diseases. In general, an increase in the dose of ultraviolet rays can weaken the human immune system, and at the same time reduce the yield of fields, reduce the already narrow base of the Earth's food supply. Scientists believe that the reason for the formation of the so-called ozone holes in the atmosphere is chlorofluorocarbons. Applications of nitrogen fertilizers in agriculture; chlorination of drinking water, firefighting, solvents and aerosols has resulted in millions of tons of chlorofluoromethanes entering the lower atmosphere as a colorless neutral gas. Spreading upwards, chlorofluoromethanes under the action of UV radiation decompose into a number of compounds, of which chlorine oxide most intensively destroys ozone. It has also been found that a lot of ozone is destroyed by the rocket engines of modern aircraft flying at high altitudes, as well as during launches of spacecraft and satellites.
International cooperation in the field of environmental protection International cooperation in solving global environmental problems is an international activity at the governmental and non-governmental levels, carried out within the framework of interstate agreements, international programs of the UN, UNESCO, etc., environmental programs and projects implemented by private and public environmental organizations. funds and aimed at uniting the efforts of states, individuals and public associations in overcoming the global environmental problems of mankind. International cooperation in the field of environmental protection is governed by international environmental law, which is based on generally recognized principles and norms. The high priority of the environmental factor in international relations is constantly increasing, which is associated with the deterioration of the environment.
Conclusion: The impact of man on the environment has assumed alarming proportions. To fundamentally improve the situation, purposeful and thoughtful actions will be needed. A responsible and efficient policy towards the environment will be possible only if we accumulate reliable data on the current state of the environment, substantiated knowledge about the interaction of important environmental factors, if we develop new methods to reduce and prevent the harm caused to Nature by Man. The problem of reasonable self-restraint of human society in relation to nature is becoming increasingly important. Of course, the course of human development, its invasion of nature cannot be stopped. Anthropogenic changes in the natural environment are inevitable, but they are not necessarily unfavorable from a scientific point of view. To create a harmonious life for people on Earth, it is necessary to establish new humanistic values, build a just society that protects nature. The hypothesis was confirmed.
Information sources ru.wikipedia.org php Big Encyclopedia of Cyril and Methodius 2008 I.Yu. Aleksashina "Universal reference book for schoolchildren. Book 1.", "ALL", 2004
Introduction.
Consequences of an oil pipeline accident. 1996
At all stages of its development, man was closely connected with the outside world. But since the emergence of a highly industrialized society, the dangerous human intervention in nature has increased dramatically, the scope of this interference has expanded, it has become more diverse and now threatens to become a global danger to humanity. The consumption of non-renewable raw materials is increasing, more and more arable land is leaving the economy, so cities and factories are being built on them. Man has to intervene more and more in the economy of the biosphere - that part of our planet in which life exists. The Earth's biosphere is currently undergoing increasing anthropogenic impact. At the same time, several of the most significant processes can be distinguished, none of which improves the ecological situation on the planet.
The most large-scale and significant is the chemical pollution of the environment by substances of a chemical nature unusual for it. Among them are gaseous and aerosol pollutants of industrial and household origin. The accumulation of carbon dioxide in the atmosphere is also progressing. Further development of this process will strengthen the undesirable trend towards an increase in the average annual temperature on the planet. Environmentalists are also alarmed by the ongoing pollution of the World Ocean with oil and oil products, which has already reached 1/5 of its total surface. Oil pollution of this size can cause significant disruption of gas and water exchange between the hydrosphere and the atmosphere. There is no doubt about the importance of chemical contamination of the soil with pesticides and its increased acidity, leading to the collapse of the ecosystem. In general, all the considered factors, which can be attributed to the polluting effect, have a significant impact on the processes occurring in the biosphere.
Chemical pollution of the biosphere.
Man has been polluting the atmosphere for thousands of years, but the consequences of the use of fire, which he used throughout this period, were insignificant. I had to put up with the fact that the smoke interfered with breathing, and that the soot lay in a black cover on the ceiling and walls of the dwelling. The resulting heat was more important to a person than clean air and unfinished cave walls. This initial air pollution was not a problem, for people then lived in small groups, occupying an immeasurably vast untouched natural environment. And even a significant concentration of people in a relatively small area, as was the case in classical antiquity, was not yet accompanied by serious consequences.
This was the case until the beginning of the nineteenth century. Only in the last hundred years has the development of industry "gifted" us with such production processes, the consequences of which at first man could not yet imagine. Million-strong cities arose, the growth of which cannot be stopped. All this is the result of great inventions and conquests of man.
Basically, there are three main sources of air pollution: industry, domestic boilers, transport. The share of each of these sources in total air pollution varies greatly from place to place. It is now generally accepted that industrial production pollutes the air the most. 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, which consume more than 70% of the annually produced solid and liquid fuels. The main harmful impurities of pyrogenic origin are the following:
Carbon monoxide. It is obtained by incomplete combustion of carbonaceous substances. It enters the air as a result of burning solid waste, with exhaust gases and emissions from industrial enterprises. At least 1250 million tons of this gas enters the atmosphere every year. Carbon monoxide is a compound that actively reacts with the constituent parts of the atmosphere and contributes to an increase in the temperature on the planet and the creation of a greenhouse effect.
Sulfur dioxide. It is emitted during the combustion of sulfur-containing fuel or the processing of sulfurous ores (up to 170 million tons per year). Part of the sulfur compounds is released during the combustion of organic residues in mining dumps. In the United States alone, the total amount of sulfur dioxide emitted into the atmosphere amounted to 65% of the global emission.
Sulfuric anhydride. It is formed during the oxidation of sulfur dioxide. The end product of the reaction is an aerosol or solution of sulfuric acid in rainwater, which acidifies the soil and exacerbates human respiratory diseases. The precipitation of sulfuric acid aerosol from smoke flares of chemical enterprises is observed at low cloudiness and high air humidity. The leaf blades of plants growing at a distance of less than 11 km from such enterprises are usually densely dotted with small necrotic spots formed at the sites of sedimentation of drops of sulfuric acid. Pyrometallurgical enterprises of non-ferrous and ferrous metallurgy, as well as thermal power plants annually emit tens of millions of tons of sulfuric anhydride into the atmosphere.
Hydrogen sulfide and carbon disulfide. They enter the atmosphere separately or together with other sulfur compounds. The main sources of emissions are enterprises for the manufacture of artificial fiber, sugar, coke, oil refineries, and oil fields. In the atmosphere, when interacting with other pollutants, they undergo slow oxidation to sulfuric anhydride.
nitrogen oxides. The main sources of emissions are enterprises producing nitrogen fertilizers, nitric acid and nitrates, aniline dyes, nitro compounds, viscose silk, and celluloid. The amount of nitrogen oxides entering the atmosphere is 20 million tons per year.
Fluorine compounds. Sources of pollution are enterprises producing aluminum, enamels, glass, ceramics, steel, and phosphate fertilizers. Fluorine-containing substances enter the atmosphere in the form of gaseous compounds - hydrogen fluoride or dust of sodium and calcium fluoride. The compounds are characterized by a toxic effect. Fluorine derivatives are strong insecticides.
Chlorine compounds. They enter the atmosphere from chemical enterprises producing hydrochloric acid, chlorine-containing pesticides, organic dyes, hydrolytic alcohol, bleach, soda. In the atmosphere, they are found as an admixture of chlorine molecules and hydrochloric acid vapors. The toxicity of chlorine is determined by the type of compounds and their concentration. In the metallurgical industry, during the smelting of pig iron and its processing into steel, various heavy metals and toxic gases are released into the atmosphere. Thus, per 1 tonne of saturated cast iron, in addition to 12.7 kg of sulfur dioxide and 14.5 kg of dust particles, which determine the amount of compounds of arsenic, phosphorus, antimony, lead, mercury vapor and rare metals, tar substances and hydrogen cyanide, are released.
Aerosol pollution of the atmosphere. Aerosols are solid or liquid particles suspended in the air. The solid components of aerosols in some cases are especially dangerous for organisms, and cause specific diseases in humans. In the atmosphere, aerosol pollution is perceived in the form of smoke, fog, mist or haze. A significant part of aerosols is formed in the atmosphere when solid and liquid particles interact with each other or with water vapor. The average size of aerosol particles is 1-5 microns. About 1 cubic meter enters the Earth's atmosphere every year. km of dust particles of artificial origin. A large number of dust particles are also formed during the production activities of people. Information about some sources of technogenic dust is given in Table 1:
Table 1
The main sources of artificial aerosol air pollution are thermal power plants that consume high-ash coal, enrichment plants, metallurgical, cement, magnesite and carbon black plants. Aerosol particles from these sources are distinguished by a wide variety of chemical composition. Most often, compounds of silicon, calcium and carbon are found in their composition, less often - oxides of metals: iron, magnesium, manganese, zinc, copper, nickel, lead, antimony, bismuth, selenium, arsenic, beryllium, cadmium, chromium, cobalt, molybdenum, as well as asbestos. An even greater variety is characteristic of organic dust, including aliphatic and aromatic hydrocarbons, acid salts. It is formed during the combustion of residual petroleum products, during the pyrolysis process at oil refineries, petrochemical and other similar enterprises. Permanent sources of aerosol pollution are industrial dumps - artificial mounds of redeposited material, mainly overburden, formed during mining or from waste from processing industries, thermal power plants. The source of dust and poisonous gases is mass blasting. So, as a result of one medium-sized explosion (250-300 tons of explosives), about 2 thousand cubic meters are released into the atmosphere. m of conditional carbon monoxide and more than 150 tons of dust. The production of cement and other building materials is also a source of air pollution with dust. The main technological processes of these industries - grinding and chemical processing of charges, semi-finished products and products obtained in hot gas streams are always accompanied by emissions of dust and other harmful substances into the atmosphere. Atmospheric pollutants include hydrocarbons - saturated and unsaturated, containing from 1 to 13 carbon atoms. They undergo various transformations, oxidation, polymerization, interacting with other atmospheric pollutants after being excited by solar radiation. As a result of these reactions, peroxide compounds, free radicals, compounds of hydrocarbons with oxides of nitrogen and sulfur are formed, often in the form of aerosol particles. Under certain weather conditions, especially large accumulations of harmful gaseous and aerosol impurities can form in the surface air layer.
This usually happens when there is an inversion in the air layer directly above the sources of gas and dust emission - the location of a layer of colder air under warm air, which prevents air masses and delays the transfer of impurities upward. As a result, harmful emissions are concentrated under the inversion layer, their content near the ground increases sharply, which becomes one of the reasons for the formation of a photochemical fog previously unknown in nature.
Photochemical fog (smog). Photochemical fog is a multicomponent mixture of gases and aerosol particles of primary and secondary origin. The composition of the main components of smog includes ozone, nitrogen and sulfur oxides, numerous organic peroxide compounds, collectively called photooxidants. Photochemical smog occurs as a result of photochemical reactions under certain conditions: the presence of a high concentration of nitrogen oxides, hydrocarbons and other pollutants in the atmosphere, intense solar radiation and calm or very weak air exchange in the surface layer with a powerful and increased inversion for at least a day. Sustained calm weather, usually accompanied by inversions, is necessary to create a high concentration of reactants.
Such conditions are created more often in June-September and less often in winter. In prolonged clear weather, solar radiation causes the breakdown of nitrogen dioxide molecules with the formation of nitric oxide and atomic oxygen. Atomic oxygen with molecular oxygen give ozone. It would seem that the latter, oxidizing nitric oxide, should again turn into molecular oxygen, and nitric oxide into dioxide. But that doesn't happen. The nitric oxide reacts with the olefins in the exhaust gases, which break down the double bond to form molecular fragments and excess ozone. As a result of the ongoing dissociation, new masses of nitrogen dioxide are split and give additional amounts of ozone. A cyclic reaction occurs, as a result of which ozone gradually accumulates in the atmosphere. This process stops at night. In turn, ozone reacts with olefins. Various peroxides are concentrated in the atmosphere, which in total form oxidants characteristic of photochemical fog. The latter are the source of the so-called free radicals, which are characterized by a special reactivity. Such smog is not uncommon over London, Paris, Los Angeles, New York and other cities in Europe and America. According to their physiological effects on the human body, they are extremely dangerous for the respiratory and circulatory systems and often cause premature death of urban residents with poor health.
The problem of controlling the emission of pollutants into the atmosphere by industrial enterprises (MPC). The priority in the development of maximum permissible concentrations in the air belongs to the USSR. MPC - such concentrations that a person and his offspring are directly or indirectly affected, do not worsen their performance, well-being, as well as sanitary and living conditions for people.
The generalization of all information on MPC, received by all departments, is carried out in the MGO (Main Geophysical Observatory). In order to determine air values based on the results of observations, the measured values of concentrations are compared with the maximum single maximum allowable concentration and the number of cases when the MPC was exceeded, as well as how many times the largest value was higher than the MPC, is determined. The average value of the concentration for a month or a year is compared with the long-term MPC - medium stable MPC. The state of air pollution by several substances observed in the atmosphere of the city is assessed using a complex indicator - the air pollution index (API). To do this, the MPC normalized to the corresponding values and the average concentrations of various substances with the help of simple calculations lead to the value of the concentrations of sulfur dioxide, and then summed up. The maximum one-time concentrations of the main pollutants were the highest in Norilsk (nitrogen and sulfur oxides), Frunze (dust), Omsk (carbon monoxide). The degree of air pollution by the main pollutants is in direct proportion to the industrial development of the city. The highest maximum concentrations are typical for cities with a population of more than 500 thousand inhabitants. Air pollution with specific substances depends on the type of industry developed in the city. If enterprises of several industries are located in a large city, then a very high level of air pollution is created, but the problem of reducing emissions of many specific substances still remains unresolved.
Chemical pollution of natural waters.
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).
inorganic pollution. The main inorganic (mineral) pollutants of fresh and marine waters are a variety of chemical compounds that are toxic to the inhabitants of the aquatic environment. These are compounds of arsenic, lead, cadmium, mercury, chromium, copper, fluorine. Most of them end up in water as a result of human activities. Heavy metals are absorbed by phytoplankton and then transferred through the food chain to more highly organized organisms. The toxic effect of some of the most common pollutants in the hydrosphere is presented in Table 2:
table 2
Degree of toxicity:
Is absent
Very weak
Weak
strong
Very strong.
In addition to the substances listed in the table, dangerous contaminants of the aquatic environment include inorganic acids and bases, which cause a wide range of pH of industrial effluents (1.0 - 11.0) and can change the pH of the aquatic environment to values of 5.0 or above 8.0, while fish in fresh and sea water can exist only in the pH range of 5.0 - 8.5. Among the main sources of pollution of the hydrosphere with minerals and biogenic elements, food industry enterprises and agriculture should be mentioned. About 6 million tons of salts are annually washed out from irrigated lands. By the year 2000 it is possible to increase their weight up to 12 million tons/year. Wastes containing mercury, lead, copper are localized in separate areas off the coast, but some of them are carried far beyond the territorial waters. Mercury pollution significantly reduces the primary production of marine ecosystems, inhibiting the development of phytoplankton. Wastes containing mercury usually accumulate in the bottom sediments of bays or river estuaries. Its further migration is accompanied by the accumulation of methyl mercury and its inclusion in the trophic chains of aquatic organisms. Thus, Minamata disease, first discovered by Japanese scientists in people who ate fish caught in the Minamata Bay, into which industrial effluents with technogenic mercury were uncontrollably discharged, became notorious.
organic pollution. Among the soluble substances introduced into the ocean from land, not only mineral and biogenic elements, but also organic residues are of great importance for the inhabitants of the aquatic environment. The removal of organic matter into the ocean is estimated at 300 - 380 million tons / year. Wastewater containing suspensions of organic origin or dissolved organic matter adversely affects the condition of water bodies. When settling, the suspensions flood the bottom and retard the development or completely stop the vital activity of these microorganisms involved in the process of water self-purification. When these sediments rot, harmful compounds and toxic substances, such as hydrogen sulfide, can be formed, which lead to pollution of all water in the river. The presence of suspensions also makes it difficult for light to penetrate deep into the water and slows down the processes of photosynthesis. One of the main sanitary requirements for water quality is the content of the required amount of oxygen in it. Harmful effect is exerted by all contaminants that in one way or another contribute to the reduction of oxygen content in water. Surfactants - fats, oils, lubricants - form a film on the surface of the water, which prevents gas exchange between water and the atmosphere, which reduces the degree of saturation of water with oxygen. A significant amount of organic matter, most of which is not characteristic of natural waters, is discharged into rivers along with industrial and domestic wastewater. Increasing pollution of water bodies and drains is observed in all industrial countries. Information on the content of some organic substances in industrial wastewater is provided in Table 3:
Table 3
Due to the rapid pace of urbanization and the somewhat slow construction of sewage treatment plants or their unsatisfactory operation, water basins and soil are polluted with household waste. Pollution is especially noticeable in slow-flowing or stagnant water bodies (reservoirs, lakes).
Decomposing in the aquatic environment, organic waste can become a medium for pathogenic organisms. Water contaminated with organic waste becomes almost unsuitable for drinking and other needs. Household waste is dangerous not only because it is a source of some human diseases (typhoid fever, dysentery, cholera), but also because it requires a lot of oxygen for its decomposition. If domestic wastewater enters the reservoir in very large quantities, then the content of soluble oxygen may drop below the level necessary for the life of marine and freshwater organisms.
The problem of pollution of the oceans (on the example of a number of organic compounds).
Oil and oil products. Oil is a viscous oily liquid that is dark brown in color and has low fluorescence. Oil consists mainly of saturated aliphatic and hydroaromatic hydrocarbons. The main components of oil - hydrocarbons (up to 98%) - are divided into 4 classes:
Paraffins (alkenes) - (up to 90% of the total composition) - stable substances, the molecules of which are expressed by a straight and branched chain of carbon atoms. Light paraffins have maximum volatility and solubility in water.
Cycloparaffins - (30 - 60% of the total composition) - saturated cyclic compounds with 5-6 carbon atoms in the ring. In addition to cyclopentane and cyclohexane, bicyclic and polycyclic compounds of this group are found in oil. These compounds are very stable and difficult to biodegrade.
Aromatic hydrocarbons - (20 - 40% of the total composition) - unsaturated cyclic compounds of the benzene series, containing 6 carbon atoms in the ring less than cycloparaffins. Oil contains volatile compounds with a molecule in the form of a single ring (benzene, toluene, xylene), then bicyclic (naphthalene), semicyclic (pyrene).
Olefins (alkenes) - (up to 10% of the total composition) - unsaturated non-cyclic compounds with one or two hydrogen atoms at each carbon atom in a molecule that has a straight or branched chain.
Oil and oil products are the most common pollutants in the oceans. By the beginning of the 1980s, about 6 million tons of oil were annually entering the ocean, which accounted for 0.23% of world production. The greatest losses of oil are associated with its transportation from production areas. Emergencies, discharge of washing and ballast water overboard by tankers - all this leads to the presence of permanent pollution fields along sea routes. In the period 1962-79, as a result of accidents, about 2 million tons of oil entered the marine environment. Over the past 30 years, since 1964, about 2,000 wells have been drilled in the World Ocean, of which 1,000 and 350 industrial wells have been equipped in the North Sea alone. Due to minor leaks, 0.1 million tons of oil are lost annually. Large masses of oil enter the seas along rivers, with domestic and storm drains.
The volume of pollution from this source is 2.0 million tons/year. Every year, 0.5 million tons of oil enters with industrial effluents. Getting into the marine environment, oil first spreads in the form of a film, forming layers of various thicknesses. By the color of the film, you can determine its thickness (Table 4):
Table 4
The oil film changes the composition of the spectrum and the intensity of light penetration into the water. Light transmission of thin films of crude oil is 1-10% (280 nm), 60-70% (400 nm).
A film with a thickness of 30-40 microns completely absorbs infrared radiation. When mixed with water, oil forms an emulsion of two types: direct - "oil in water" - and reverse - "water in oil". Direct emulsions, composed of oil droplets with a diameter of up to 0.5 μm, are less stable and are typical for oils containing surfactants. When volatile fractions are removed, oil forms viscous inverse emulsions, which can remain on the surface, be carried by the current, wash ashore and settle to the bottom.
Pesticides. Pesticides are a group of man-made substances used to control pests and plant diseases. Pesticides are divided into the following groups: insecticides - to combat harmful insects, fungicides and bactericides - to combat bacterial plant diseases, herbicides - against weeds. It has been established that pesticides, destroying pests, harm many beneficial organisms and undermine the health of biocenoses. In agriculture, there has long been a problem of transition from chemical (polluting) to biological (environmentally friendly) methods of pest control. Currently, more than 5 million tons of pesticides enter the world market. About 1.5 million tons of these substances have already entered the terrestrial and marine ecosystems by ash and water. The industrial production of pesticides is accompanied by the appearance of a large number of by-products that pollute wastewater. In the aquatic environment, representatives of insecticides, fungicides and herbicides are more common than others. Synthesized insecticides are divided into three main groups: organochlorine, organophosphorus and carbonates. Organochlorine insecticides are obtained by chlorination of aromatic and heterocyclic liquid hydrocarbons. These include DDT and its derivatives, in the molecules of which the stability of aliphatic and aromatic groups in the joint presence increases, various chlorinated derivatives of chlorodiene (eldrin). These substances have a half-life of up to several decades and are very resistant to biodegradation. In the aquatic environment, polychlorinated biphenyls are often found - derivatives of DDT without an aliphatic part, numbering 210 homologues and isomers. Over the past 40 years, more than 1.2 million tons of polychlorinated biphenyls have been used in the production of plastics, dyes, transformers, and capacitors. Polychlorinated biphenyls (PCBs) enter the environment as a result of industrial wastewater discharges and the incineration of solid waste in landfills. The latter source delivers PBCs to the atmosphere, from where they fall out with atmospheric precipitation to all regions of the globe. Thus, in snow samples taken in Antarctica, the content of PBC was 0.03 - 1.2 kg/l.
Synthetic surfactants. Detergents (surfactants) belong to an extensive group of substances that lower the surface tension of water. They are part of synthetic detergents (SMC), widely used in everyday life and industry. Together with wastewater, surfactants enter the continental waters and the marine environment. SMS contain sodium polyphosphates, in which detergents are dissolved, as well as a number of additional ingredients that are toxic to aquatic organisms: flavoring agents, bleaching agents (persulphates, perborates), soda ash, carboxymethylcellulose, sodium silicates. Depending on the nature and structure of the hydrophilic part of the surfactant molecules, they are divided into anionic, cationic, amphoteric, and nonionic. The latter do not form ions in water. The most common among the surfactants are anionic substances. They account for more than 50% of all surfactants produced in the world. The presence of surfactants in industrial wastewater is associated with their use in such processes as the flotation concentration of ores, the separation of chemical technology products, the production of polymers, the improvement of conditions for drilling oil and gas wells, and the fight against equipment corrosion. In agriculture, surfactants are used as part of pesticides.
Compounds with carcinogenic properties. Carcinogenic substances are chemically homogeneous compounds that exhibit transforming activity and the ability to cause carcinogenic, teratogenic (violation of embryonic development processes) or mutagenic changes in organisms. Depending on the conditions of exposure, they can lead to growth inhibition, accelerated aging, disruption of individual development, and changes in the gene pool of organisms. Substances with carcinogenic properties include chlorinated aliphatic hydrocarbons, vinyl chloride, and especially polycyclic aromatic hydrocarbons (PAHs). The maximum amount of PAHs in the current sediments of the World Ocean (more than 100 µg/km of dry matter mass) was found in tentonically active zones subject to deep thermal action. The main anthropogenic sources of PAHs in the environment are the pyrolysis of organic substances during the combustion of various materials, wood, and fuel.
Heavy metals. Heavy metals (mercury, lead, cadmium, zinc, copper, arsenic) are common and highly toxic pollutants. They are widely used in various industrial productions, therefore, despite the treatment measures, the content of heavy metal compounds in industrial wastewater is quite high. Large masses of these compounds enter the ocean through the atmosphere. Mercury, lead and cadmium are the most dangerous for marine biocenoses. Mercury is transported to the ocean with continental runoff and through the atmosphere. During the weathering of sedimentary and igneous rocks, 3.5 thousand tons of mercury are released annually. The composition of atmospheric dust contains about 12 thousand tons of mercury, and a significant part is of anthropogenic origin. About half of the annual industrial production of this metal (910 thousand tons/year) ends up in the ocean in various ways. In areas polluted by industrial waters, the concentration of mercury in solution and suspension is greatly increased. At the same time, some bacteria convert chlorides into highly toxic methylmercury. Contamination of seafood has repeatedly led to mercury poisoning of the coastal population. By 1977, there were 2,800 victims of the Minomata disease, which was caused by waste from the production of vinyl chloride and acetaldehyde, which used mercury chloride as a catalyst. Insufficiently treated wastewater from enterprises entered the Minamata Bay. Pigs are a typical trace element found in all components of the environment: in rocks, soils, natural waters, the atmosphere, and living organisms. Finally, pigs are actively dispersed into the environment during human activities. These are emissions from industrial and domestic effluents, from smoke and dust from industrial enterprises, from exhaust gases from internal combustion engines. The migration flow of lead from the continent to the ocean goes not only with river runoff, but also through the atmosphere. With continental dust, the ocean receives (20-30) tons of lead per year.
Discharge of waste into the sea for the purpose of disposal (dumping). Many countries with access to the sea carry out marine burial of various materials and substances, in particular soil excavated during dredging, drill slag, industrial waste, construction waste, solid waste, explosives and chemicals, and radioactive waste. The volume of burials amounted to about 10% of the total mass of pollutants entering the World Ocean. The basis for dumping in the sea is the ability of the marine environment to process a large amount of organic and inorganic substances without much damage to the water. However, this ability is not unlimited.
Therefore, dumping is considered as a forced measure, a temporary tribute to the imperfection of technology by society. Industrial slags contain a variety of organic substances and heavy metal compounds. Household waste contains on average (by weight of dry matter) 32-40% organic matter; 0.56% nitrogen; 0.44% phosphorus; 0.155% zinc; 0.085% lead; 0.001% mercury; 0.001% cadmium. During the discharge, the passage of the material through the water column, part of the pollutants goes into solution, changing the quality of the water, the other is sorbed by suspended particles and goes into bottom sediments. At the same time, the turbidity of the water increases. The presence of organic substances often leads to the rapid consumption of oxygen in water and often to its complete disappearance, the dissolution of suspensions, the accumulation of metals in dissolved form, and the appearance of hydrogen sulfide.
The presence of a large amount of organic matter creates a stable reducing environment in the soil, in which a special type of interstitial water appears, containing hydrogen sulfide, ammonia, and metal ions. Benthic organisms and others are affected to varying degrees by the discharged materials. In the case of the formation of surface films containing petroleum hydrocarbons and surfactants, gas exchange at the air-water interface is disrupted. Pollutants entering the solution can accumulate in the tissues and organs of hydrobiants and have a toxic effect on them. The dumping of dumping materials to the bottom and prolonged increased turbidity of the given water leads to the death of inactive forms of benthos from suffocation. In surviving fish, mollusks and crustaceans, the growth rate is reduced due to the deterioration of feeding and breathing conditions. The species composition of a given community often changes. When organizing a system of control over the discharge of waste into the sea, the definition of dumping areas, the determination of the dynamics of pollution of sea water and bottom sediments is of decisive importance. To identify possible volumes of discharge into the sea, it is necessary to carry out calculations of all pollutants in the composition of the material discharge.
Thermal pollution. Thermal pollution of the surface of reservoirs and coastal marine areas occurs as a result of the discharge of heated wastewater from power plants and some industrial production. The discharge of heated water in many cases causes an increase in water temperature in reservoirs by 6-8 degrees Celsius. The area of heated water spots in coastal areas can reach 30 square meters. km. A more stable temperature stratification prevents water exchange between the surface and bottom layers. The solubility of oxygen decreases, and its consumption increases, since with increasing temperature, the activity of aerobic bacteria that decompose organic matter increases. The species diversity of phytoplankton and the entire flora of algae is increasing.
Based on the generalization of the material, it can be concluded that the effects of anthropogenic impact on the aquatic environment are manifested at the individual and population-biocenotic levels, and the long-term effect of pollutants leads to a simplification of the ecosystem.
Soil pollution.
The soil cover of the Earth is the most important component of the Earth's biosphere. It is the soil shell that determines many processes occurring in the biosphere.
The most important significance of soils is the accumulation of organic matter, various chemical elements, and energy. The soil cover functions as a biological absorber, destroyer and neutralizer of various contaminants. If this link of the biosphere is destroyed, then the existing functioning of the biosphere will be irreversibly disrupted. That is why it is extremely important to study the global biochemical significance of the soil cover, its current state and changes under the influence of anthropogenic activity. One of the types of anthropogenic impact is pesticide pollution.
Pesticides as a polluting factor. The discovery of pesticides - chemical means of protecting plants and animals from various pests and diseases - is one of the most important achievements of modern science. Today in the world 300 kg of chemicals are applied per 1 hectare. However, as a result of long-term use of pesticides in agriculture and medicine (vector control), there is almost universally a decline in effectiveness due to the development of resistant pest strains and the spread of "new" pests whose natural enemies and competitors have been destroyed by pesticides. At the same time, the effect of pesticides began to manifest itself on a global scale. Of the huge number of insects, only 0.3% or 5 thousand species are harmful. Pesticide resistance has been found in 250 species. This is exacerbated by the phenomenon of cross-resistance, which consists in the fact that increased resistance to the action of one drug is accompanied by resistance to compounds of other classes. From a general biological point of view, resistance can be considered as a change in populations as a result of the transition from a sensitive strain to a resistant strain of the same species due to selection caused by pesticides. This phenomenon is associated with genetic, physiological and biochemical rearrangements of organisms. Excessive use of pesticides (herbicides, insecticides, defoliants) negatively affects soil quality. In this regard, the fate of pesticides in soils and the possibilities and possibilities of neutralizing them by chemical and biological methods are being intensively studied. It is very important to create and use only drugs with a short lifespan, measured in weeks or months. Some progress has already been made in this area and drugs with a high rate of destruction are being introduced, but the problem as a whole has not yet been resolved.
Acid atmospheric impacts on land. One of the most acute global problems of today and the foreseeable future is the problem of increasing acidity of precipitation and soil cover. Areas of acidic soils do not know droughts, but their natural fertility is lowered and unstable; they are rapidly depleted and yields are low. Acid rain causes not only acidification of surface waters and upper soil horizons. Acidity with downward water flows extends to the entire soil profile and causes significant acidification of groundwater. Acid rain occurs as a result of human economic activity, accompanied by the emission of colossal amounts of oxides of sulfur, nitrogen, and carbon. These oxides, entering the atmosphere, are transported over long distances, interact with water and turn into solutions of a mixture of sulfurous, sulfuric, nitrous, nitric and carbonic acids, which fall in the form of "acid rain" on land, interacting with plants, soils, waters. The main sources in the atmosphere are the burning of shale, oil, coal, gas in industry, agriculture, and at home. Human economic activity has almost doubled the entry of sulfur oxides, nitrogen, hydrogen sulfide and carbon monoxide into the atmosphere. Naturally, this affected the increase in the acidity of atmospheric precipitation, ground and ground waters. To solve this problem, it is necessary to increase the volume of systematic representative measurements of atmospheric pollutant compounds over large areas.
Conclusion.
The protection of nature is the task of our century, a problem that has become a social one. Again and again we hear about the danger threatening the environment, but still many of us consider them an unpleasant, but inevitable product of civilization and believe that we will still have time to cope with all the difficulties that have come to light.
However, human impact on the environment has taken on alarming proportions. To fundamentally improve the situation, purposeful and thoughtful actions will be needed. A responsible and efficient policy towards the environment will be possible only if we accumulate reliable data on the current state of the environment, substantiated knowledge about the interaction of important environmental factors, if we develop new methods to reduce and prevent the harm caused to Nature by Man.
