Textbook: Environmental problems of chemical technology. Ecological problems

Chemical industry enterprises are located in most regions of the Russian Federation and produce a wide range of products to meet the needs of all industries, agriculture and the population. The chemical complex of the Russian Federation includes 26 branches of the chemical, petrochemical, agrochemical and microbiological industries. The variety of products, technologies used and types of raw materials determines a wide range of pollutants in atmospheric air, water basins and soils. A number of emissions, discharges and industrial wastes are characterized by significant volumes, high toxicity and waste generation. In some localities, the impact of chemical enterprises on the environment is dominant.

In recent years, the volumes of emissions, discharges and waste generation have decreased significantly, which is largely explained by the decline in production and, to a lesser extent, by the implementation of environmental measures.

Due to the variety of processes involved, the chemical industry is one of the most difficult to control emissions.

The main sources of harmful emissions into the atmosphere in industry are the production of acids (sulfuric, hydrochloric, nitric, phosphoric, etc.), the production of rubber products, phosphorus, plastics, dyes and detergents, artificial rubber, mineral fertilizers, solvents (toluene, acetone, phenol, benzene), oil cracking.

Solving environmental problems in the industry is complicated by the operation of a significant number of morally and physically obsolete equipment, of which 60% have been in operation for more than 10 years, up to 20% for more than 20 years, 10% for more than 30 years.

It should be noted that this industry maintains a high level of purification of emissions of harmful substances (more than 90%). The structure of emissions is characterized by the following data: solid substances (fuel oil, coal ash, BVK dust protein, inorganic dust) - 13.4% of the total emissions, liquid and gaseous substances - 86.6%, including carbon monoxide - 32.6% , volatile organic compounds -g- 24.4; sulfur dioxide - 19.3, nitrogen oxides - 8.8, hydrocarbons - 4.8%. Emissions of sulfur dioxides, nitrogen oxides, and carbon oxides are largely associated with the operation of thermal power plants and boiler houses that are part of the enterprises of the complex.

The main amount of nitrogen oxides and sulfur dioxides is emitted by the agrochemical industry, carbon oxide - by the soda industry, fuel oil ash - by the microbiological industry, carbon disulfide and hydrogen sulfide - by the chemical fiber industry, ammonia - by the agrochemical industry, organochlorines - by the chlorine industry, olefins - by the synthetic rubber industry, gasoline - tire industry.

In addition, chemical and petrochemical industries are characterized by emissions of metallic mercury, which account for about half of the total volume of emissions of this substance by Russian industry, as well as vanadium (V) oxide and hexavalent chromium, which are classified as hazard class I substances.

Of the total volume of water used by chemical enterprises, 62% is accounted for by the chemical industry, 29.2% by the petrochemical industry, and 9.8% by the microbiological industry. Fresh water savings through the use of recirculating systems amounted to 90% (from 96% in the synthetic rubber industry to 64% in the microbiological industry).

The discharge of contaminated wastewater in 1994 amounted to 1.62 km 3, wastewater discharges petroleum products, suspended sulfates, total phosphorus, cyanides, thiocyanides, cadmium, cobalt, manganese, copper, nickel, mercury, lead, chromium, zinc, hydrogen sulfide, carbon disulfide, alcohols, benzene, formaldehyde, furfural, phenol, surfactants, pesticides.

The chemical and petrochemical industries annually generate 125 million tons of waste, of which about 30% is used. Every year, industry enterprises do not use more than 90 million tons of waste, of which more than 30 million tons (sulfuric and hydrochloric acids, solvents, bottoms) and more than 50 million tons (distilled suspension sludge, phosphogypsum, lime and gypsum waste) are stored in specially designated areas.

Over 7.8 million tons of waste, or 73% of the total amount in the chemical complex, was generated in the agrochemical industry. The vast majority of this is hazard class IV waste, the main types of which are phosphogypsum, phosphoric acid production and halite dumps from the flotation enrichment of calcium chloride. 86 and 105 million tons have been stored, respectively. Storage is associated with the alienation of significant areas and soil acidification. The proven technologies for industrial processing of phosphogypsum were not widely used: the demand for the resulting building materials turned out to be limited.

According to the State Statistics Committee of the Russian Federation, enterprises of the chemical and petrochemical industries make a small gross contribution to air pollution in Russia - half of all emissions in Russia from stationary sources. The same share is made up of emissions of liquid and gaseous substances. At the same time, the industry’s most significant share is in metallic mercury emissions (about half of the all-Russian volume).

The industry accounts for less than 5% of the volume of fresh water used in the Russian Federation and 6% of the volume of wastewater discharged into surface water bodies.

Industries have a certain significance in the volume of discharge of wastewater pollution into natural water bodies of Russia - X general industrial discharge of wastewater of this category. The industry’s contribution in terms of the volume of discharge of regulatory-treated wastewater is almost the same.

BASF's activities include the production of raw materials and energy resources, various chemicals, agricultural products, plastics, dyes, textile auxiliaries, as well as consumer products such as varnishes, paints, information systems and medicines.

Based on the main raw materials - naphtha, natural gas, sulfur, etc. the company produces more than 8 thousand different products. A large number of by-products that are obtained are not destroyed, but serve as feedstock for other industries.

Corporate strategy

Already in 1985, BASF was one of the first in its activities to be guided by the “fundamental law” aimed at solving environmental problems. The established rules are included in the corporate strategy, which is mandatory for all BASF production facilities, regardless of their geographical location.

Of these corporate rules, we especially note the following:

• Following the principles of Sustainable Development.

The concept of "Sustainable Development" was formulated at the UN conference in 1992 in Rio de Janeiro and involves a process that meets the economic, environmental and social needs of modern society, while simultaneously enabling future generations to achieve their goals.

• Participation in the "Responsible Care" initiative - a program of global chemical manufacturers, which involves a number of voluntary measures aimed at preserving the environment, ensuring safety and health.
• Economic interests do not take precedence over safety, health and environmental issues
• Release of products that are safe to produce, use, destroy
• Minimal environmental impact during production, storage, transportation, and use of products
• Helping consumers use products safely
• Continuous development of science and technology to improve safety and environmental protection.

It is clear from these rules that BASF considers safety, health and environmental protection issues to be of utmost importance and priority, both in existing production facilities and in the development of new products and processes.

Measures to reduce emissions

The company's costs associated with environmental protection amounted to more than 1.5 billion marks in 1998 alone. (Fig. 1). One example of the company's success in this activity is the reduction of emissions at BASF's headquarters in Ludwigshafen, volume? which in recent years has decreased by an order of magnitude (Fig. 2).

The complex and integrated nature of chemical production, which includes approximately 350 workshops at the Ludwigshafen site alone, places special demands on environmental monitoring. The latter consists of environmental monitoring (air, noise, water quality, soil monitoring at 43 locations inside and outside the site), energy and water management and waste and effluent management. For waste disposal, BASF uses the largest special plant in Europe, in 8 furnaces of which 200 thousand tons of waste are processed annually.

The environmental safety concept is based on qualified, well-trained personnel, modern production technologies with the highest safety standards for all countries in which BASF has production.

These standards, which also include waste minimization, are laid down already at the design stage, which makes it possible to avoid production waste, reduce it or recycle it.

Examples of solving environmental problems.

Let's look at a few examples from the firm's experience in catalytic chemistry and process chemicals.

BASF produces catalysts for the oxidation of waste gases from various industries, including chemical industries. The use of these catalysts has led to a reduction in unwanted emissions into the atmosphere. Recently, the company has developed new honeycomb catalysts for the removal of dioxins, which are successfully used not only in the chemical industry, but also in waste processing at waste incineration plants in many cities around the world.

In chemical production, the use of the basic principles of catalysis is very effective, as it makes it possible to increase the selectivity of the process while simultaneously reducing energy costs. In today's chemical industry, catalysts play a key role in about 80% of the various processes. One example of the significant progress that the company has made in reducing the harmful effects of byproducts on the environment is the catalyst for the synthesis of acrylic acid. The latter is widely used in production variances?, varnishes, superabsorbents, etc. The synthesis of acrylic acid from propylene occurs through two catalytic steps. Over 25 years of research, the amount of unwanted by-products has decreased by 75%. The positive effect of the catalyst was manifested both in a more complete use of the feedstock for its intended purpose (increased selectivity) and in the formation of less waste, which led to a significant reduction in energy consumption. The latter is due to the fact that costs at the stages of rectification and extraction have decreased. In addition, it turned out to be possible to regenerate the spent catalyst.

Another example is the production of vinyl chloride at the BASF site in Antwerp. The vinyl chloride workshop was put into operation more than 30 years ago, so there was a need for its complete modernization, also due to the fact that the service life allowed by Flemish legislation was ending. An important intermediate in the production of vinyl chloride is dichloroethane, obtained by oxychlorination of ethylene in the presence of HCl and air. This process is accompanied by the formation of by-product gases: CO, chlorinated hydrocarbons. In addition, the reaction mixture contains nitrogen from the air. In order to reduce the amount of gases, it was decided to use oxygen as an oxidizing agent.

After modernization, only the reactors and some units of heat exchange equipment remained from the equipment; everything else was replaced.

Currently, this production produces a significantly smaller amount of by-product gases; in addition, 20% more HCl is used than before from neighboring workshops, which was not utilized before modernization.

The water produced in the process is contaminated with organochlorine compounds. To reduce the negative impact on the environment, it was decided to install an additional column - a regenerator, in which organochlorines are removed.

This production also uses cooling water, which before the modernization of the workshop was sent directly to the pool of the nearby port. After carrying out the necessary engineering work, a double closed system was created that completely prevents the possibility of organic substances entering the seawater. Two new storage facilities for liquid dichloroethane with a capacity of 8 thousand m 3 were also installed with double shell? for greater safety. Necessary improvements were also made in the production management system. In total, about 70 million marks were invested in this project.

Let's look at one example related to the removal of acidic process gases. This is a very energy-intensive process, which, moreover, usually leads to deep corrosion of equipment. In this regard, BASF has developed the aMDEA (activated methyl diethanolamine) process, which provides high productivity, low energy consumption and increased corrosion resistance of equipment. To date, more than 100 units are using this process and several more units are being designed, renovated, or built.

The functional principle of the aMDEA method is based on the high absorption capacity of the tertiary amine (N-methyl-diethanolamine) with respect to the acid gases CO 2 and H 2 S. The ability to change the activator concentration over a wide range allows you to take advantage of both chemical and physical purification methods. The high solubility of acid gases leads to a reduction in energy costs, and the low solubility of inerts contributes to finer purification. Other advantages of the solvent include high chemical and thermal stability, low saturated vapor pressure, which significantly reduces solvent losses. Low corrosion, achieved by selecting the optimal activator, eliminates the need to use corrosion inhibitors, has a positive effect on the economics of the entire process and minimizes the negative impact on the environment.

In the field of process chemicals produced by BASF, in addition to aMDEA, another solvent that has proven itself to be excellent is N-methylpyrrolidone (NMP). Its area of ​​application is the industrial production of hydrocarbons by extractive distillation. This technology takes advantage of the high solubility of hydrocarbons in NMP. Compared to other technical solvents, NMP has a number of important advantages: it does not form azeotropes with hydrocarbons and has high thermal and chemical stability. In addition, compared to other extractants, N-methylpyrrolidone has more favorable characteristics from the point of view of toxicology and ecology.

Public information

Although chemistry plays a key role in maintaining and improving quality of life, this is not always recognized by society. Thus, a public opinion poll conducted by the European Chemical Industry Council (CEFIC) in 1994 showed that about 60% of respondents had a negative attitude towards the chemical industry. Only one in three respondents believe that the chemical industry cares about the environment, and less than half believe that the industry is researching and implementing technologies that solve environmental problems.

To correct this imbalance in public opinion, BASF is committed to educating employees, consumers and the public about the safe use and handling of chemical products and its efforts to address environmental issues. The company's reports are periodically published, which describe in detail both the current state of the environment in production and BASF's environmental goals in the future.

Meetings with representatives of various political parties, environmentalists, and open days have become a tradition, during which an open dialogue is held on all issues of mutual interest. In all of these interactions, BASF's goal is to align the firm's interests with the needs of society, which is key to future success.

Murzin D.Yu.

According to statistical data, the environmental situation in northern Crimea leaves much to be desired: in terms of soil and water pollution, the autonomy is slightly inferior to regions with developed industry, including the Krivoy Rog and Dnieper regions.

Many consider the chemical industry to be the main culprit in the current situation, represented in northern Crimea by several enterprises, the largest of which are Crimean Titan CJSC and Crimean Soda Plant OJSC.

Currently, the main environmental problems in the chemical industry of northern Crimea are caused by the following factors:

• the presence of solid industrial waste subject to accumulation, storage and disposal;
• pollution of water used in the technological cycle;
• emissions of exhaust gases and dust into the atmosphere.

Indirect environmental problems of the chemical industry of northern Crimea are:

• high energy intensity of production, which affects the environmental situation as a whole;
• use of natural resources as hydromineral raw materials.

As a result of the above problems, chemical industry enterprises are forced to limit production. In particular, Lake Krasnoye, used by the Crimean Soda Plant as an evaporation storage tank, is already filled to the permitted level, which prevents the growth of production volumes. A similar situation is observed at Crimean Titan: the area of ​​acid and sludge storage facilities is 42 square meters. km, but this is not enough for full-scale production. In addition, there is an acute problem with the disposal of phosphogypsum, one of the types of toxic waste from chemical production.

Contrary to the hype raised by the media around the environmental problems of the chemical industry in northern Crimea, allegations about the inactivity of chemical industry enterprises are unfounded. Proof of this is the multi-million dollar investments of manufacturers in solving environmental problems. Today, the chemical industry is more interested than anyone else in reducing emissions and disposing of industrial waste as quickly as possible.

Currently, the northern part of Crimea is constantly monitoring the state of the environment. It is noteworthy that chemical industry enterprises also conduct regular inspections using their own departments. For example, at Crimean Titan there is an environmental center whose task is to implement environmental protection measures and assess the impact of production on the environment. “Crimean Soda Plant” also has a modern laboratory, with the help of which it carries out instrumental tests to determine the level of industrial pollution.

The results of such actions are easy to evaluate using numbers. For example, in 2010, at the Crimean Soda Plant, the level of harmful emissions was reduced by 30% compared to 2009, and this was without a decline in production. Similar dynamics are observed at Crimean Titan: not so long ago the enterprise received the international certificate ISO 14001:2008, certifying the production’s compliance with environmental standards.

The environmental problems of the chemical industry in northern Crimea cannot be underestimated - they exist, and they are objective. However, solving these problems requires participation not only from producers, but also from the state, which until now has played the role of a passive observer or punitive body. It is no secret that chemical industry enterprises are budget-generating enterprises in northern Crimea: chemical industry tax deductions are measured in numbers with tens of zeros. Thus, the state has a direct interest in solving environmental problems that limit production growth; however, the state has not yet shown its interest - for the most part, the chemical industry solves environmental problems on its own.

The chemical industry is one of the most rapidly developing industries. It belongs to the industries that form the basis of modern scientific and technological progress. In the structure of the chemical industry, with all the importance of basic chemistry, the leading position has passed to the industry of plastics, chemical fibers, dyes, pharmaceuticals, detergents and cosmetics.

Reagents and materials produced by the chemical industry are widely used in technological processes in a wide variety of industries. In the modern era, the chemical industry has become a kind of indicator that determines the degree of modernization of the economic mechanism of any country.

It is advisable to distinguish 5 groups of production within the Russian chemical industry:

• 1. Mining and chemical industry, including the extraction of primary chemical raw materials.
• 2. Basic chemistry, specializing in the production of mineral fertilizers, acids, soda and other substances that constitute, as it were, “food” for other sectors of the economy.
• 3. Production of polymer substances.
• 4. Processing of polymer materials.
• 5. A heterogeneous group of other, slightly interconnected branches of this industry: photochemical, household chemicals, etc.
• 6. Household chemicals are a sub-sector of the chemical industry that has currently undergone significant development. Everyone, in one way or another, almost constantly either uses the “fruits” of the chemical industry, or is faced with activities that require knowledge of safe handling of substances. A good housewife will never place a bottle of acetic acid next to other similar food containers. An educated person always reads the instructions before working with household liquids such as chlorine bleach or glass cleaners, and knows that after covering the floor with new linoleum or carpet, it is always necessary to ventilate the room. All of these are techniques for safe handling of substances. The ability to prepare solutions, knowledge of methods for purifying substances, the properties of the most common compounds, their effect on human health - the younger generation learns all this in chemistry lessons at school. The main problems in the development of the industry are related to the environment. It should be noted that currently the development of industry, including the chemical industry, significantly aggravates environmental problems. Scientific and technological progress develops productive forces, improves human living conditions, and increases its level. At the same time, growing human intervention sometimes introduces changes into the environment that can lead to irreversible consequences in an ecological and biological sense. The result of man's active influence on nature is its pollution, clogging, and depletion. As a result of human economic activity, the gas composition and dust content of the lower layers of the atmosphere change. Thus, when waste from industrial chemical production is released, a large amount of suspended particles and various gases enter the atmosphere. Highly biologically active chemical compounds can cause long-term effects on humans: chronic inflammatory diseases of various organs, changes in the nervous system, effects on the intrauterine development of the fetus, leading to various abnormalities in newborns. For example, according to the Volgograd Center for Hydrometeorology, over the past 5 years the level of pollution with dust, nitrogen oxides, soot, ammonia, and formaldehyde has increased 2-5 times. This mainly occurs due to imperfect technological processes. High pollution with hydrogen chloride and organochlorine substances in the southern industrial zone of Volgograd is explained by the frequent lack of raw materials at chemical enterprises, which leads to the operation of equipment at reduced loads, at which it is very difficult to maintain technological standards.

The main contribution to air pollution in the city of Volgograd comes from petrochemical enterprises (35%). Amount of harmful substances emitted by petrochemical enterprises: hydrogen sulfide - 0.4 thousand tons per year, phenol - 0.3 thousand tons per year, ammonia - 0.5 thousand tons per year, hydrogen chloride - 0.2 thousand tons in year.

All of the above is explained by a number of factors, ranging from the low quality of raw materials to the unsatisfactory condition of process equipment and dust and gas collection devices in enterprises as a whole.

Industrial enterprises, for example, Khimprom, Kaustik, the Volzhsky nitrogen-oxygen plant, an organic synthesis plant, and numerous storage ponds of other enterprises cause enormous damage to the floodplain. Particular harm is caused to soils with a low content of humus and organic matter, as well as carbonate chernozems. In them, fine fractions of carbonates, which are unstable to the effects of acid precipitation, may predominate as adhesives. And the removal of the lipid fraction under the influence of organic solvents emitted by enterprises into the atmosphere can, together with other factors, lead to the loss of the agronomically valuable structure of irrigated lands and their withdrawal from agricultural use. Through soil, chemicals can enter food, water and air.

Industrial waste enters water bodies and quickly destroys the ecological connections that have developed in nature over thousands of years. With chronic impacts, degradation of aquatic ecosystems located in the area where liquid waste storage facilities are located occurs. Chemicals contained in wastewater can migrate into groundwater and then enter open water bodies. Thus, more than 50% of the components detected (in wastewater) came from wastewater storage tanks into groundwater and 38% into the World Ocean. Liquid effluents from chemical industries also have an adverse effect on the processes of natural self-purification of water in the seas and oceans. Thus, violation of wastewater treatment regulations and the placement of wastewater in storage tanks and evaporators is accompanied by intense pollution of environmental objects, in particular, the seas and oceans of the planet.

It should be noted that in the last 5-7 years the quality of the waters in our country has improved somewhat. This is explained by the fact that many leading industrial enterprises have curtailed their production programs. So, in 1980-91. in Volga water, mercury was determined in the range of 0.013-0.069 μ/l, significantly exceeding the MPC. Then (before 1995) mercury was detected in lower concentrations - up to 0.0183 μg/l, and after 1996 it was not detected. Currently, many (but not all!) indicators of the Volga from the point of view of economic and cultural water use do not exceed the maximum permissible concentration.

Environmental problems can only be solved by stabilizing the economic situation and creating an economic mechanism for environmental management in which the payment for environmental pollution will correspond to the costs of its complete cleanup.

In general, the following directions for solving environmental problems created by the chemical industry can be identified:

• · compliance with regulations, state standards and other regulatory documents in the field of environmental protection;
• · operation of treatment facilities, control equipment;
• · implementation of plans and measures for environmental protection;
• · compliance with requirements, norms and rules during placement, construction, commissioning, operation and decommissioning of chemical industry facilities;
• · fulfillment of the requirements specified in the conclusion of the state environmental assessment.

Ecological problems

Chemistry teacher MOUSOSH No. 9 Shapkina Zh.A.

"CHEMICAL POLLUTION OF THE ENVIRONMENT BY INDUSTRY"

At all stages of his development, man was closely connected with the world around him. But since the emergence of a highly industrialized society, dangerous human intervention in nature has sharply increased, the scope of this intervention 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 built on it. Man has to increasingly intervene in the economy of the biosphere - that part of the planet in which life exists. The Earth's biosphere is currently subject to increasing anthropogenic impact. At the same time, several of the most significant processes can be identified, any of which does not improve the environmental situation on the planet.

The most widespread and significant is chemical pollution of the environment with substances of a chemical nature that are unusual for it. Among them are gaseous and aerosol pollutants of industrial and domestic origin. The accumulation of carbon dioxide in the atmosphere is also progressing. The further development of this process will strengthen the undesirable trend towards an increase in the average annual temperature on the planet. Environmentalists are also concerned about the ongoing pollution of the World Ocean with oil and petroleum products, which has already reached 1/5 of its total surface.

Oil pollution of this size can cause significant disruptions in 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 factors considered that can be attributed to the polluting effect have a noticeable impact on the processes occurring in the biosphere.

The development of industry and transport, an increase in population, human penetration into space, the intensification of agriculture (the use of fertilizers and plant protection products), the development of the oil refining industry, the burial of hazardous chemicals at the bottom of the seas and oceans, as well as waste from nuclear power plants, nuclear weapons testing - everything These are sources of global and increasing pollution of the natural environment - land, water, air.

All this is the result of great inventions and conquests of man.

There are basically three main sources of air pollution: industry, domestic boilers, and transport. The contribution of each of these sources to total air pollution varies greatly depending on location. It is now generally accepted that industrial production produces the most air pollution. Sources of pollution are thermal power plants, which emit sulfur dioxide and carbon dioxide into the air along with smoke; 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 burning fuel for industrial needs. Heating of homes, transport, combustion and recycling of household and industrial waste. Atmospheric pollutants are divided into primary, which enter directly into the atmosphere, and secondary, which are the result of the transformation of the latter.

Thus, sulfur dioxide gas entering the atmosphere is oxidized to sulfuric anhydride, which reacts 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, physicochemical reactions between pollutants and atmospheric components, other secondary characteristics are formed.

The main harmful impurities are the following:

A) Carbon monoxide . It is produced by incomplete combustion of carbonaceous substances. It enters the air as a result of the combustion of solid waste, with exhaust gases and emissions from industrial enterprises. Every year, at least 250 million tons of this gas enter the atmosphere. Carbon monoxide is a compound that actively reacts with components of the atmosphere, and contributes to an increase in temperature on the planet and the creation of a greenhouse effect.

b) Sulfur dioxide . Released during the combustion of sulfur-containing fuel or processing of sulfur ores. Some sulfur compounds are released during the combustion of organic residues in mining dumps. In the USA alone, the total amount of sulfur dioxide released into the atmosphere amounted to 65% of global emissions.

V) Sulfuric anhydride . Formed by 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 aggravates diseases of the human respiratory tract. The fallout of sulfuric acid aerosol from smoke flares of chemical plants is observed under low cloudiness and high air humidity. The leaf blades of plants growing at a distance of less than 1 km from such enterprises are usually densely dotted with small necrotic spots formed in places where drops of sulfuric acid settled. Non-ferrous and ferrous metallurgy enterprises, as well as thermal power plants, annually emit tens of millions of tons of sulfuric anhydride into the atmosphere.

G) Hydrogen sulfide and carbon disulfide . They enter the atmosphere separately or together with other sulfur compounds. The main sources of emissions are enterprises producing artificial fiber and sugar; coke, oil refining, and oil fields. In the atmosphere, when interacting with other pollutants, they undergo slow oxidation to sulfuric anhydride.

d) Nitrogen oxides . The main sources of emissions are enterprises producing nitrogen fertilizers, nitric acid, nitrates, aniline dyes, nitro compounds, viscose silk, and celluloid. The amount of nitrogen oxides entering the atmosphere is 20 million tons/year.

e) 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 calcium and sodium fluoride dust. The compounds are characterized by a toxic effect. Fluorine derivatives are strong insecticides.

and) Chlorine compounds. They come into the atmosphere from chemical plants producing hydrochloric acid, chlorine-containing pesticides, organic dyes, hydrolytic alcohol, bleach, and soda. In the atmosphere they are found as impurities 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, when smelting cast iron and processing it into steel, various heavy metals and toxic gases are released into the atmosphere. Thus, per one ton of cast iron, in addition to 2.7 kg of sulfur dioxide and 4.5 kg of dust particles are released, which determine the amount of compounds of arsenic, phosphorus, antimony, lead, mercury vapor and rare metals, resinous substances and hydrogen cyanide.

Aerosol air pollution Aerosols are solid or liquid particles suspended in the air. In some cases, solid components of aerosols are especially dangerous for organisms and cause specific diseases in people. In the atmosphere, aerosol pollution is perceived as smoke, fog, haze or haze. A significant portion of aerosols are formed in the atmosphere through the interaction of solid and liquid particles with each other or with water vapor. The average size of aerosol particles is 1 – 5 µm. About 1 cubic km enters the Earth's atmosphere annually. dust particles of artificial origin. A large number of dust particles are also formed during human production activities. Information about some sources of industrial dust is given below.

DUST EMISSION PRODUCTION PROCESS

(million tons/year)

1. Coal combustion 93.60

2. Iron smelting 20.21

3. Copper smelting (without purification) 6.23

4. Zinc smelting 0.18

5. Tin smelting (without purification) 0.004

6. Lead smelting 0.13

7. Cement production 53.37

The main sources of artificial aerosol air pollution are thermal power plants that consume high-ash coal, enrichment plants, metallurgical and cement plants. Aerosol particles from these pollution sources have a wide variety of chemical compositions. Most often, compounds of silicon, calcium and carbon are found in their composition, less often - metal oxides: iron, magnesium, manganese, zinc, copper, nickel, lead, antimony, bismuth, selenium, arsenic, beryllium, cadmium, chromium, cobalt, molybdenum, as well as asbestos. Even greater diversity is characteristic of organic dust, including aliphatic and aromatic hydrocarbons and acid salts. It is formed during the combustion of residual petroleum products, during the pyrolysis process at oil refineries, petrochemical and other similar enterprises. Constant sources of aerosol pollution are industrial dumps - artificial embankments of redeposited material, mainly overburden rocks formed during mining or from waste from processing industry enterprises, thermal power plants. Massive blasting operations serve as a source of dust and toxic gases. Thus, as a result of one average-mass explosion (250 - 300 tons of explosives), about 2 thousand cubic meters are released into the atmosphere. conventional carbon monoxide and more than 150 tons of dust. The production of cement and other building materials is also a source of dust pollution.

Atmospheric pollutants include hydrocarbons - saturated and unsaturated, containing from 1 to 13 carbon atoms. They undergo various transformations, oxidation, and polymerization. Interacting with other atmospheric pollutants after excitation by solar radiation. As a result of these reactions, peroxide compounds, free radicals, and hydrocarbon compounds with nitrogen and sulfur oxides are formed, often in the form of aerosol particles. Under certain weather conditions, particularly large accumulations of harmful gaseous and aerosol impurities may form in the ground layer of air. This usually happens in cases where 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 warmer air, which prevents air masses and delays the upward transfer of impurities. As a result, harmful emissions are concentrated in the inversion sublayer, their content near the ground increases sharply, which becomes one of the reasons for the formation of photochemical fog, previously unknown in nature.

Photochemical fog (smog) is a multicomponent mixture of gases and aerosol particles of primary and secondary origin. The main components of smog include ozone, nitrogen and sulfur oxides, and numerous organic compounds collectively called photooxidants.

Photochemical smog occurs as a result of photochemical reactions under certain conditions: the presence in the atmosphere of a high concentration of nitrogen oxides, hydrocarbons and other pollutants, intense solar radiation and calmness, or very weak air exchange in the surface layer with a powerful and increased inversion for at least a day.

Smog is a common phenomenon over London, Paris, Los Angeles, New York and other cities in Europe and America. Due to their physiological effects on the human body, they are extremely dangerous for the respiratory and circulatory systems and often cause premature death in urban residents with poor health.

Chemical pollution of natural waters.

Every body of water or water source is connected with its surrounding external environment. It is influenced by the conditions for the formation of surface or underground water flow, various natural phenomena, industry, industrial and municipal construction, transport, economic and domestic human activities. The consequence of these influences is the introduction into the aquatic environment of substances unusual for it - pollutants that worsen the quality of water. Pollutants entering the aquatic environment are classified differently, depending on approaches, criteria and objectives. Thus, chemical, physical and biological contaminants are usually isolated. 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 (oil and oil products, organic residues, surfactants, pesticides).

Inorganic pollution. The main inorganic (mineral) pollutants of fresh and sea 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 activity. Heavy metals are absorbed by phytoplankton and then transferred along the food chain to higher organisms. Among the main sources of hydrosphere pollution with minerals and nutrients, food industry enterprises and agriculture should be mentioned. About 6 million tons are washed away from irrigated lands annually. salts By 2000, their mass may increase to 12 million tons/year. Waste containing mercury, lead, and copper is localized in certain areas near the coast, but some of it is carried far beyond the territorial waters. Mercury pollution significantly reduces the primary production of marine ecosystems, suppressing the development of phytoplankton. Waste containing mercury usually accumulates 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 Minamata Bay, into which industrial wastewater containing technogenic mercury was uncontrolled, became notorious.

All contaminants that in one way or another contribute to a decrease in the oxygen content in water have a harmful effect. Surfactants – fats. Oils and lubricants form a film on the surface of the water that prevents gas exchange between water and the atmosphere, which reduces the degree of oxygen saturation of the water.

POLLUTANTS – QUANTITY IN WORLD RUNOFF, million tons/year:

1. Petroleum products – 26,563

2. Phenols – 0.460

3. Waste from synthetic fiber production – 5,500

4. Plant organic residues – 0.170

5. Total – 33,273

Due to the rapid pace of urbanization and the somewhat slow construction of treatment facilities or their unsatisfactory operation, water basins and soil are polluted by household waste. If household wastewater enters a body of water in very large quantities, the content of dissolved oxygen may drop below the level necessary for the life of marine and freshwater organisms.

The problem of pollution of the World Ocean (using the example of a number of organic compounds).

Oil and petroleum products are the most common pollutants in the world's oceans. By the beginning of the 80s, about 6 million tons entered the ocean annually. oil, which accounted for 0.23% of world production. The greatest oil losses are associated with its transportation from production areas. Emergency situations, tankers draining washing and ballast water overboard - all this causes the presence of permanent fields of pollution along sea routes.

Pesticides constitute a group of artificially created substances used to combat 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, while destroying pests, harm many beneficial organisms and undermine the health of biocenoses. Industrial production of pesticides is accompanied by the emergence of a large number of by-products that pollute wastewater. Representatives of insecticides, fungicides and herbicides are most often found in the aquatic environment.

Carcinogens – these are chemically homogeneous compounds that exhibit transforming activity and the ability to cause carcinogenic, teratogenic (disruption 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 carbons, vinyl chloride, and especially polycyclic aromatic hydrocarbons (PAHs).

Dumping of waste into the sea for the purpose of disposal (dumping) .

Many countries with access to the sea carry out marine disposal of various materials and substances, in particular dredging soil, drilling 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 at sea is the ability of the marine environment to process large quantities of organic and inorganic substances without much damage to water. However, this ability is not unlimited. Therefore, dumping is seen as a forced measure, a temporary tribute from society to the imperfection of technology.

When organizing a control system for waste discharges into the sea, the determination of dumping areas and the dynamics of pollution of sea water and bottom sediments are of decisive importance. To identify possible volumes of discharge into the sea, it is necessary to carry out calculations of all pollutants in the material discharge.

Thermal pollution surfaces of reservoirs and coastal marine areas as a result of the discharge of heated wastewater by 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 sq. km. This 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.

Soil pollution.

The Earth's soil cover is the most important component of the biosphere. It is the soil shell that determines many of the processes occurring in the biosphere.

The most important importance of soils is the accumulation of organic matter, various chemical elements, and energy. Soil cover functions as a biological absorber, destroyer and neutralizer of various pollutants. If this link 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 activities.

The discovery of pesticides - chemical means of protecting plants and animals from various pests and diseases - is one of the most important achievements of science. Today, 300 kg of chemicals are applied per 1 hectare in the world. However, as a result of the long-term use of pesticides in agriculture and medicine (the fight against disease vectors), almost everywhere it is characterized by a decrease in their effectiveness due to the development of resistant races of pests and the spread of “new” harmful organisms, the natural enemies and competitors of which were destroyed by pesticides. In this regard, the fate of pesticides in soils and the possibility 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.

One of the most pressing global problems of our time and the foreseeable future is the problem of increasing acidity of precipitation and soil cover.

Areas of acidic soils do not experience droughts, but their natural fertility is reduced and unstable; They are quickly depleted and their yields are low. Acid rain not only causes acidification of surface waters and upper soil horizons. Acidity with downward flows of water spreads across 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 sulfuric, sulfuric, nitrous, nitric and carbonic acids, which fall in the form of “acid rain” on land, interacting with plants, soils, and waters. The main sources in the atmosphere are the combustion of shale, oil, coal, and gas in industry, agriculture, and everyday life. Human economic activity has almost doubled the release of oxides of sulfur, nitrogen, hydrogen sulfide and carbon monoxide into the atmosphere. Naturally, this affected the increase in acidity of atmospheric precipitation, surface and groundwater. To solve this problem, it is necessary to increase the volume of systematic measurements of air polluting compounds over large areas.

Conclusion.

Nature conservation is the task of our century, a problem that has become social. Time and again we hear about the dangers threatening the environment, but many of us still consider them an unpleasant but inevitable product of civilization and believe that we will still have time to cope with all the difficulties that have arisen. However, human impact on the environment has reached alarming proportions. To fundamentally improve the situation, targeted and thoughtful actions will be needed. A responsible and effective policy towards the environment will be possible only if we accumulate reliable data on the current state of the environment, sound knowledge about the interaction of important environmental factors, and if we develop new methods for reducing and preventing harm caused to Nature by Man.