The chemical industry is the first producer of non-recyclable waste. Ecological problems

Beginning of the 20th century was marked in the chemical industry by great successes in the use of atmospheric nitrogen. The development of the organic synthesis and petrochemical industries has led to a significant increase in demand for chlorine, since chlorination is still an indispensable stage in many processes. The chemical industry has transformed from an industry of inorganic substances (soda, sulfuric acid, hydrochloric acid, then the production of fertilizers) into an industry of petrochemical synthesis. This process was accompanied by a change in the raw material base - at first only rock salt, limestone, pyrite, then Chilean saltpeter, phosphorites, and potassium salts. With the development of organic chemistry, coal becomes the most important raw material of the chemical industry. The coke industry emerges. However, with the development of the chemical industry, problems of environmental pollution have increased, issues of environmental protection have arisen, etc.

Raw materials of the chemical industry, connection with environmental protection. The raw material base of the chemical industry is differentiated depending on the natural and economic characteristics of individual countries and regions. In some areas it is coal, coke oven gas, in others it is oil, associated petroleum gases, salts, sulfur pyrites, gas waste from ferrous and non-ferrous metallurgy, in the third it is table salt, etc.

The raw material factor influences the specialization of territorial combinations of chemical production. Chemical production, as technological methods improve, can, in turn, influence the raw material base. The chemical industry is associated with many industries. It is combined with oil refining, coal coking, ferrous and non-ferrous metallurgy, and the timber industry.

Chemical industry and environmental problems. Chemical pollution is solid, gaseous and liquid substances, chemical elements and compounds of artificial origin that enter the biosphere, disrupting the processes of circulation of substances and energy established by nature. The most common harmful gas pollutants are: oxides of sulfur (sulfur) - SO2, SO3; hydrogen sulfide (H2S); carbon disulfide (CS2); oxides of nitrogen (nitrogen) - Nox; benzopyrene; ammonia; chlorine compounds; fluorine compounds; hydrogen sulfide; hydrocarbons; synthetic surfactants; carcinogens; heavy metals; carbon oxides - CO, CO2.

By the end of the 20th century. Environmental pollution from waste, emissions, sewage from all types of industrial production, agriculture, and urban municipal services has become global in nature and has brought humanity to the brink of an environmental disaster. Modern life, which has changed significantly due to the widespread use of chemical products, has turned into a dangerous source of pollution of the biosphere. Household waste contains a significant amount of synthetic and artificial substances that are not absorbed in nature. This means they are removed from natural geochemical cycles for a long time. Burning household waste is often impossible due to the fact that the environment is polluted with toxic combustion products (soot, polycyclic aromatic hydrocarbons, organochlorine compounds, hydrochloric acid, etc.). Therefore, landfills of used tires and plastic packaging arise. Such landfills turn out to be good ecological niches for rats and associated microorganisms. Cases of fires cannot be excluded, which can turn entire areas into an environmental disaster zone (decreased transparency of the atmosphere, toxic combustion products, etc.). Therefore, there is an acute problem of creating polymers that, under natural conditions, quickly self-destruct and return to the normal geochemical cycle.

A special group consists of the production of chemical warfare agents, medicines and plant protection products, since this is the synthesis of biologically active substances. First of all, the production process itself is associated with a significant risk, since personnel constantly work in an atmosphere with a high concentration of these substances. Significant difficulties are associated with the storage and, as it now turns out, with the destruction of chemical warfare agents. Chemical plant protection products, or pesticides, designed specifically for spraying into the biosphere. It is difficult to name the total number of these poisons, since new ones are constantly being released and the release of old ones is being discontinued, which turned out to be very harmful in practice or the types of pests against which they are used have already adapted to them. But approximately their number has already exceeded 1000 compounds, mainly chlorine-, phosphorus-, arsenic- and organomercury.

Thus, hydrocarbons enter the atmosphere during fuel combustion, and from the oil refining industry, and from the gas production industry. The sources of pollutants are varied, and the types of waste and the nature of their impact on the components of the biosphere are also numerous. The biosphere is polluted by solid waste, gas emissions and wastewater from metallurgical, metalworking and machine-building factories. Wastewater from the pulp and paper, food, woodworking, and petrochemical industries causes enormous harm to water resources. The development of road transport has led to the pollution of the atmosphere of cities and transport communications with heavy metals and toxic hydrocarbons, and the constant increase in the scale of maritime transport has caused almost universal pollution of the seas and oceans with oil and petroleum products. The massive use of mineral fertilizers and chemical plant protection products has led to the appearance of pesticides in the atmosphere, soil and natural waters, pollution of reservoirs, watercourses and agricultural products with nutrients (nitrates, pesticides, etc.). During mining, millions of tons of various, often phytotoxic rocks are extracted to the surface of the earth, forming waste heaps and dumps that generate dust and burn.

During the operation of chemical plants and thermal power plants, huge amounts of solid waste (cinder, slag, ash, etc.) are also generated, which are stored over large areas, having a negative impact on the atmosphere, surface and ground water, soil cover (dust, excretion gases, etc.). On the territory of Ukraine there are 877 chemically hazardous facilities and 287,000 facilities use highly toxic substances or their derivatives in their production (in 140 cities and 46 settlements).

The increase in chemical production has also led to an increase in the amount of industrial waste that poses a danger to the environment and people. The chemical-technological transformation of nature by man, along with the mechanical change of landscapes and the structure of the earth's crust, is the main means of negative impact on the biosphere. Therefore, there is a need to analyze the chemical and technological activities of mankind: to identify its historical and cultural forms, scale and structure. The chemical activity of mankind is very diverse and accompanies it almost from the first steps of scientific practice. Strictly speaking, the chemical processing of nature is an integral feature of all living things.

The “human-environment” system is in a state of dynamic equilibrium, in which an ecologically balanced state of the natural environment is maintained, in which living organisms, including humans, interact with each other and the abiotic (non-living) environment surrounding them without disturbing this balance.

In the era of scientific and technological revolution, the increasing role of science in the life of society often leads to all sorts of negative consequences of the use of scientific achievements in military affairs (chemical weapons, atomic weapons), industry (some designs of nuclear reactors), energy (lowland hydroelectric power stations), agriculture (salinization soil, poisoning of river runoff), healthcare (production of untested drugs) and other areas of the national economy. A violation of the equilibrium state between a person and his environment can already have global consequences in the form of deterioration of the habitat, destruction of natural ecological systems, and changes in the gene pool of the population. According to WHO, 20-40% of people's health depends on the state of the environment, 20-50% on lifestyle, 15-20% on genetic factors.

Based on the depth of the environmental reaction, they are divided into:

Disturbance, temporary and reversible change in the environment.

Pollution, the accumulation of technogenic impurities (substances, energy, phenomena) coming from outside or generated by the environment itself as a result of anthropogenic impact.

Anomalies, stable but local quantitative deviations of the environment from the state of equilibrium. With prolonged anthropogenic impact, the following may occur:

Environmental crisis, a state in which its parameters approach the permissible limits of deviations.

Destruction of the environment, a condition in which it becomes unsuitable for human habitation or use as a source of natural resources.

To prevent such a harmful effect of the anthropogenic factor, the concept of maximum permissible concentrations of substances (maximum permissible concentrations of substances) was introduced - a concentration of substances that does not have a direct or indirect effect on a person, does not reduce performance, and does not affect health and mood.

Maximum concentrations of some pollutants in the air of the working area

To assess toxicity, the properties of the substance (solubility in water, volatility, pH, temperature and other constants) and the properties of the environment where it has entered (climatic characteristics, properties of the reservoir and soil) are determined.

Monitoring - observation (tracking) of the state of the environment in order to detect changes in this state, their dynamics, speed and direction. The summary data obtained as a result of long-term observations and numerous analyzes makes it possible to predict the environmental situation for a number of years in advance and take measures to eliminate adverse impacts and phenomena. This work is professionally carried out by special organizations - biosphere reserves, sanitary and epidemiological stations, environmental hospitals, etc.

Air sampling.

The air biosample may be relatively small;

In laboratory conditions, a biosample is formed from air in a liquid state;

The biological sample is taken using a collecting device: a sampling aspirator, a Rychter absorption device with an absorption solution. The shelf life of the samples taken is no more than 2 days;

In a confined space, an air sample is taken in the center of the room, at a height of 0.75 and 1.5 m from the floor

Water sampling.

Samples are taken using pipettes, burettes, and volumetric flasks (demonstration to students).

A liquid sample is taken from a closed volume after it has been thoroughly mixed.

A biological sample of a homogeneous liquid is taken from the flow at certain time intervals and in different places.

To obtain reliable results, biosamples of natural water must be analyzed within 1-2 hours after collection.

To take biosamples at different depths, special sampling devices are used - bathometers, the main part of which is a cylindrical vessel with a capacity of 1-3 liters, equipped with lids at the top and bottom. After immersion in the liquid to a given depth, the cylinder lids are closed, and the sample vessel is raised to the surface.

Sampling of solid matter.

A biosample of solid substances must be representative of the material being tested (contain the maximum possible diversity in the composition of the test material; for example, to control the quality of tablets, it is advisable to analyze not a single tablet, but to mix a certain amount of them and take a sample from this mixture corresponding to the average weight of one tablet ).

When taking samples, they strive for the greatest possible homogenization of the material, achieved mechanically (grinding, crushing).

Biosamples from solid biosubstrates are converted into a liquid-phase biosample.

For this purpose, special technological techniques are used: preparation of solutions, suspensions, colloids, pastes and other liquid media.

Preparation of aqueous soil extract.

Procedure: Grind the soil sample thoroughly in a mortar. Take 25 g of soil, transfer it to a 200 ml flask and add 50 ml of distilled water. Shake the contents of the flask thoroughly and let it sit for 5-10 minutes, and then, after briefly shaking, filter into a 100 ml flask through a dense filter. If the filtrate is cloudy, repeat filtration through the same filter until a clear filtrate is obtained.

Determination of indicators characterizing the organoleptic properties of water.

Organoleptic properties are standardized according to the intensity of their perception by humans. These are smell, taste, color, transparency, turbidity, temperature, impurities (film, aquatic organisms).

Experiment No. 1. Determination of water transparency.

Reagents: 3 water samples (from different areas of Penza).

Equipment: 3 measuring cylinders, plastic plate, marker.

Progress. Pour different water samples into a measuring cylinder. Place a white plastic plate with a black permanent cross on it at the bottom of each cylinder. Shake the water before measuring. Transparency, depending on the amount of suspended particles, is determined by the height of the water column in the cylinder (in cm), through which the contour of the cross is visible.

Determination of the smell of water.

Natural odors of water are associated with the vital activity of plants and animals or the rotting of their remains; artificial odors with the ingress of industrial or waste water.

There are aromatic, swampy, putrefactive, woody, earthy, moldy, fishy, ​​hydrogen sulfide, grassy and vague odors.

The strength of the odor is determined using a 5-point system:

score - no odor or very weak (usually not noticeable).

score - weak (discovered if you pay attention to it).

point - noticeable (easily noticed and can cause disapproving comments about the water).

point - distinct (capable of causing abstinence from drinking).

points - very strong (so strong that the water is completely undrinkable).

Determination of water color.

Color is a natural property of water due to the presence of humic substances, which give it a yellowish to brown color. Humic substances are formed during the destruction of organic compounds in the soil, are washed out of it and enter open water bodies. Therefore, color is characteristic of the water of open reservoirs and increases sharply during the flood period.

Reagents: water samples, distilled water.

Equipment: 4 beakers, a sheet of white paper.

Work progress: Determination is carried out by comparing it with distilled water. To do this, take 4 identical beakers and fill them with water - one distilled, the other - the test one. Against the background of a sheet of white paper, compare the observed color: colorless, light brown, yellowish.

Determination of indicators characterizing the chemical composition and properties of water.

Indicators such as dry residue, total hardness, pH, alkalinity, content of cations and anions: Ca 2+, Na +, HCO 3 -, Cl -, Mg 2+ characterize the natural composition of water.

Determination of water density.

Determination of pH (hydrogen value).

The pH value is affected by the content of carbonates, hydroxides, salts susceptible to hydrolysis, humic substances, etc. This indicator is an indicator of pollution of open reservoirs when acidic or alkaline wastewater is released into them. As a result of chemical and biological processes occurring in water and loss of carbon dioxide, the pH of the water can change rapidly, and this indicator should be determined immediately after sampling, preferably at the sampling site.

Detection of organic substances.

Procedure: Take 2 test tubes, pour 5 ml of distilled water into one of them, and into the other - the test tube. Add a drop of 5% potassium permanganate solution to each test tube.

Experiment No. 7. Detection of chloride ions.

The high solubility of chlorides explains their widespread distribution in all natural waters. In flowing water bodies, the chloride content is usually low (20-30 mg/l). Uncontaminated groundwater in areas with non-saline soil usually contains up to 30-50 mg/l of chlorion. In water filtered through saline soil, 1 liter can contain hundreds and even thousands of milligrams of chlorides. Water containing chlorides in a concentration of more than 350 mg/l has a salty taste, and at a chloride concentration of 500-1000 mg/l it has an adverse effect on gastric secretion. The chloride content is an indicator of contamination of underground and surface water sources and wastewater.

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.

The main problems of modern chemistry

2. Chemical industry and environmental problems of chemistry

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. Zelenin K.N., Sergutina V.P., Solod O.V. Taking the chemistry exam. St. Petersburg, 2001. pp. 2-3. .

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 these are techniques for safe handling of substances. For more details, see: Artamonova V. Shampoos: chemistry and biology in one bottle // Chemistry and life. 2001. No. 4. pp. 36-40. . The ability to prepare solutions, knowledge of methods for purifying substances, the properties of the most common compounds, their impact on human health - the younger generation will learn all this in chemistry lessons at school. For more details, see: “Round table” at the Third Moscow Pedagogical Marathon of Academic Subjects on April 8, 2004 “Where to start studying chemistry, or How to get interested in chemistry” // Chemistry (Pervoe September Publishing House). 2004. No. 33. pp. 3-7..

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. See: Alexandrov Yu.V., Borzenko A.S. , Polyakov A.V. Population health as a criterion of the social and ecological state of the territory // Volga Ecological Bulletin: Vol. 4. Volgograd, 2003. P. 34..

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 per year Ibid. P. 35. .

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. Chemicals can enter food, water and air through the soil. See: Kovshov V.P., Golubchik M.M., Nosonov A.M. Use of natural resources and nature conservation. Saransk, 2002. P. 56. .

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 wastewater from chemical production also has an adverse effect on the processes of natural self-purification of water in the seas and oceans. Ibid.. 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:

Ш compliance with regulations, state standards and other regulatory documents in the field of environmental protection;

Ш operation of treatment facilities, control equipment;

Ш implementation of plans and measures for environmental protection;

Ш compliance with the requirements, norms and rules during the placement, construction, commissioning, operation and decommissioning of chemical industry facilities;

Ш fulfillment of the requirements specified in the conclusion of the state environmental assessment.

Adipic acid

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Historical overview of the main stages in the development of chemistry

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Synthesis of ammonium dichromate

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Improving targeted delivery of biologically active substances to individual organs and target cells

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Essential oils

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The “human-environment” system is in a state of dynamic equilibrium, in which an ecologically balanced state of the natural environment is maintained, in which living organisms, including humans, interact with each other and the abiotic (non-living) environment surrounding them without disturbing this balance.

In the era of scientific and technological revolution, the increasing role of science in the life of society often leads to all sorts of negative consequences of the use of scientific achievements in military affairs (chemical weapons, atomic weapons), industry (some designs of nuclear reactors), energy (lowland hydroelectric power stations), agriculture (salinization soil, poisoning of river runoff), healthcare (production of untested drugs) and other areas of the national economy. A violation of the equilibrium state between a person and his environment can already have global consequences in the form of deterioration of the habitat, destruction of natural ecological systems, and changes in the gene pool of the population. According to WHO, 20-40% of people's health depends on the state of the environment, 20-50% on lifestyle, 15-20% on genetic factors.

Based on the depth of the environmental reaction, they are divided into:

Disturbance, temporary and reversible change in the environment.

Pollution, the accumulation of technogenic impurities (substances, energy, phenomena) coming from outside or generated by the environment itself as a result of anthropogenic impact.

Anomalies, stable but local quantitative deviations of the environment from the state of equilibrium. With prolonged anthropogenic impact, the following may occur:

Environmental crisis, a state in which its parameters approach the permissible limits of deviations.

Destruction of the environment, a condition in which it becomes unsuitable for human habitation or use as a source of natural resources.

To prevent such a harmful effect of the anthropogenic factor, the concept of maximum permissible concentrations of substances (maximum permissible concentrations of substances) was introduced - a concentration of substances that does not have a direct or indirect effect on a person, does not reduce performance, and does not affect health and mood.

Maximum concentrations of some pollutants in the air of the working area

To assess toxicity, the properties of the substance (solubility in water, volatility, pH, temperature and other constants) and the properties of the environment where it has entered (climatic characteristics, properties of the reservoir and soil) are determined.

Monitoring - observation (tracking) of the state of the environment in order to detect changes in this state, their dynamics, speed and direction. The summary data obtained as a result of long-term observations and numerous analyzes makes it possible to predict the environmental situation for a number of years in advance and take measures to eliminate adverse impacts and phenomena. This work is professionally carried out by special organizations - biosphere reserves, sanitary and epidemiological stations, environmental hospitals, etc.

Air sampling.

The air biosample may be relatively small;

In laboratory conditions, a biosample is formed from air in a liquid state;

The biological sample is taken using a collecting device: a sampling aspirator, a Rychter absorption device with an absorption solution. The shelf life of the samples taken is no more than 2 days;

In a confined space, an air sample is taken in the center of the room, at a height of 0.75 and 1.5 m from the floor

Water sampling.

Samples are taken using pipettes, burettes, and volumetric flasks (demonstration to students).

A liquid sample is taken from a closed volume after it has been thoroughly mixed.

A biological sample of a homogeneous liquid is taken from the flow at certain time intervals and in different places.

To obtain reliable results, biosamples of natural water must be analyzed within 1-2 hours after collection.

To take biosamples at different depths, special sampling devices are used - bathometers, the main part of which is a cylindrical vessel with a capacity of 1-3 liters, equipped with lids at the top and bottom. After immersion in the liquid to a given depth, the cylinder lids are closed, and the sample vessel is raised to the surface.

Sampling of solid matter.

A biosample of solid substances must be representative of the material being tested (contain the maximum possible diversity in the composition of the test material; for example, to control the quality of tablets, it is advisable to analyze not a single tablet, but to mix a certain amount of them and take a sample from this mixture corresponding to the average weight of one tablet ).

When taking samples, they strive for the greatest possible homogenization of the material, achieved mechanically (grinding, crushing).

Biosamples from solid biosubstrates are converted into a liquid-phase biosample.

For this purpose, special technological techniques are used: preparation of solutions, suspensions, colloids, pastes and other liquid media.

Preparation of aqueous soil extract.

Procedure: Grind the soil sample thoroughly in a mortar. Take 25 g of soil, transfer it to a 200 ml flask and add 50 ml of distilled water. Shake the contents of the flask thoroughly and let it sit for 5-10 minutes, and then, after briefly shaking, filter into a 100 ml flask through a dense filter. If the filtrate is cloudy, repeat filtration through the same filter until a clear filtrate is obtained.

Determination of indicators characterizing the organoleptic properties of water.

Organoleptic properties are standardized according to the intensity of their perception by humans. These are smell, taste, color, transparency, turbidity, temperature, impurities (film, aquatic organisms).

Experiment No. 1. Determination of water transparency.

Reagents: 3 water samples (from different areas of Penza).

Equipment: 3 measuring cylinders, plastic plate, marker.

Progress. Pour different water samples into a measuring cylinder. Place a white plastic plate with a black permanent cross on it at the bottom of each cylinder. Shake the water before measuring. Transparency, depending on the amount of suspended particles, is determined by the height of the water column in the cylinder (in cm), through which the contour of the cross is visible.

Determination of the smell of water.

Natural odors of water are associated with the vital activity of plants and animals or the rotting of their remains; artificial odors with the ingress of industrial or waste water.

There are aromatic, swampy, putrefactive, woody, earthy, moldy, fishy, ​​hydrogen sulfide, grassy and vague odors.

The strength of the odor is determined using a 5-point system:

score - no odor or very weak (usually not noticeable).

score - weak (discovered if you pay attention to it).

point - noticeable (easily noticed and can cause disapproving comments about the water).

point - distinct (capable of causing abstinence from drinking).

points - very strong (so strong that the water is completely undrinkable).

Determination of water color.

Color is a natural property of water due to the presence of humic substances, which give it a yellowish to brown color. Humic substances are formed during the destruction of organic compounds in the soil, are washed out of it and enter open water bodies. Therefore, color is characteristic of the water of open reservoirs and increases sharply during the flood period.

Reagents: water samples, distilled water.

Equipment: 4 beakers, a sheet of white paper.

Work progress: Determination is carried out by comparing it with distilled water. To do this, take 4 identical beakers and fill them with water - one distilled, the other - the test one. Against the background of a sheet of white paper, compare the observed color: colorless, light brown, yellowish.

Determination of indicators characterizing the chemical composition and properties of water.

Indicators such as dry residue, total hardness, pH, alkalinity, content of cations and anions: Ca 2+, Na +, HCO 3 -, Cl -, Mg 2+ characterize the natural composition of water.

Determination of water density.

Determination of pH (hydrogen value).

The pH value is affected by the content of carbonates, hydroxides, salts susceptible to hydrolysis, humic substances, etc. This indicator is an indicator of pollution of open reservoirs when acidic or alkaline wastewater is released into them. As a result of chemical and biological processes occurring in water and loss of carbon dioxide, the pH of the water can change rapidly, and this indicator should be determined immediately after sampling, preferably at the sampling site.

Detection of organic substances.

Procedure: Take 2 test tubes, pour 5 ml of distilled water into one of them, and into the other - the test tube. Add a drop of 5% potassium permanganate solution to each test tube.

Experiment No. 7. Detection of chloride ions.

The high solubility of chlorides explains their widespread distribution in all natural waters. In flowing water bodies, the chloride content is usually low (20-30 mg/l). Uncontaminated groundwater in areas with non-saline soil usually contains up to 30-50 mg/l of chlorion. In water filtered through saline soil, 1 liter can contain hundreds and even thousands of milligrams of chlorides. Water containing chlorides in a concentration of more than 350 mg/l has a salty taste, and at a chloride concentration of 500-1000 mg/l it has an adverse effect on gastric secretion. The chloride content is an indicator of contamination of underground and surface water sources and wastewater.

Table 2. Determination of chloride ion concentration

The concentration of SO 2-4 ions can be determined by comparing the result obtained with the data contained in Table 3:

Experiment No. 9. Determination of iron (II) and iron (III) ions.

High iron content worsens the organoleptic properties of water, makes water unsuitable for butter, cheese and textile production, and increases the proliferation of iron-absorbing microorganisms in water pipes, which leads to pipe overgrowth. The iron content in tap water should not exceed 0.3 mg/l. Iron is found in large quantities in some wastewaters, for example, in wastewater from pickling shops, wastewater from textile dyeing, etc.

Overall hardness ( N total) - This is a natural property of water due to the presence of divalent cations in it (mainly calcium and magnesium).

There are general, carbonate, permanent and removable hardness.

Removable‚ or temporary‚ ( N time) and carbonate ( N k) hardness is caused by the presence of bicarbonates (and carbonates) of calcium and magnesium.

Water with a hardness of more than 10 mEq/L often has an unpleasant taste. A sharp transition when using from soft to hard water (and sometimes vice versa) can cause dyspeptic symptoms in people.

The course of kidney stone disease worsens when using very hard water. Hard water contributes to the appearance of dermatitis. With an increased intake of calcium into the body from drinking water against the background of iodine deficiency, goiter occurs more often.

When boiling, bicarbonates turn into poorly soluble carbonates and precipitate, which leads to the formation of scale, and water hardness decreases. But boiling does not completely destroy bicarbonates, and some of them remain in solution. Removable (temporary) hardness is determined experimentally and shows how much water hardness has decreased after 1 hour of boiling. Removable hardness is always less than carbonate hardness. Irreversible, permanent (H POST) and non-carbonate hardness ( N Nk) caused by chloride, sulfate and other non-carbonate salts of calcium and magnesium. These types of stiffness are calculated by the difference:

N post.= N total - N time ; N nc = N about. - N to

Soft water - total hardness< 3,5 мг-экв/л.

Water of medium hardness - total hardness from 3.5 to 7 mEq/l.

Hard water - total hardness from 7 to 10 mEq/l.

Very hard water - total hardness > 10 mEq/l.

For drinking purposes they prefer water of medium hardness, for household and industrial purposes - soft water.

Based on this, the total hardness for water that is not subject to special treatment is set at 7 mEq/l.

To determine the total hardness, the trilonometric method is used. The main working solution is Trilon B - disodium salt of ethylenediaminetetraacetic acid:

Determination of the total content of calcium and magnesium ions is based on the ability of Trilon B to form strong complex compounds with these ions in an alkaline environment, replacing free hydrogen ions with cations Ca 2+ And M g 2+ :

Ca 2+ + Na 2 H 2 R → Na 2 CaR + 2H+,

where R is the radical of ethylenediaminetetraacetic acid.

Black chromogen is used as an indicator, giving a wine-red compound with Mg 2+, when it disappears M g 2+ it takes on a blue color. The reaction occurs at pH-10, which is achieved by adding an ammonia buffer solution to the sample ( NH 4 OH+ NH 4 CI). Calcium ions bind first, followed by magnesium.

Determination is interfered with by copper ions (>0.002 mg/l), manganese (>0.05 mg/l), iron (>1.0 mg/l), aluminum (>2.0 mg/l).

The total hardness in mEq/l is calculated using the formula:

N general mg/eq = n∙N ∙ 1000/V‚

n is the amount of Trilon B spent on titration, in ml;

V- sample volume, in ml;

N- normality of Trilon B.

Determination of dry residue

Dry residue is the amount of dissolved salts in milligrams contained in 1 liter of water.T. because the mass of organic substances in the dry residue does not exceed 10-15%, the dry residue gives an idea of ​​the degree of mineralization of the water.

The mineral composition of water is 85% or more determined by cations Ca 2+ M g 2+ , Na+ and anions NSO 3 - , CI - , SO 4 2-

The rest of the mineral composition is represented by macroelements Na+, K + , PO 4 3 - etc. and microelements Fe 2+, Fe 3+, I - , C 2+ , Mo and etc.

Water with a dry residue of up to 1000 mg/l is called fresh, over 1000 mg/l - mineralized. Water containing an excessive amount of mineral salts is unsuitable for drinking, because it has a salty or bitter-salty taste, and its consumption (depending on the composition of the salts) leads to various unfavorable physiological abnormalities in the body. On the other hand, low-mineralized water with a dry residue below 50-100 mg/l is unpleasant to the taste; prolonged use can also lead to some unfavorable physiological changes in the body (decreased chloride content in tissues, etc.). Such water, as a rule, contains little fluoride and other trace elements.

Low mineralized water - contains< 20-100 мг/л солей.

Satisfactorily mineralized water - 100-300 mg/l salts.

Highly mineralized water - contains 300-500 mg/l of salts.

Determination of soil structure.

Soil structure refers to its ability to break down into individual particles, which are called structural units. They can have different shapes: lumps, prisms, plates, etc.

Incorrect and excessive application of mineral fertilizers and methods of their storage cause contamination of soils and agricultural products. Water-soluble forms of nitrogen fertilizers flow into ponds, rivers, streams, and reach groundwater, causing an increased content of nitrates, which adversely affects human health.

Very often, fertilizers are applied to the soil unpurified, which causes soil contamination with radioactive (for example, potassium isotopes when using potassium fertilizers), as well as toxic substances. Various forms of superphosphates, having an acidic reaction, contribute to acidification of the soil, which is undesirable for areas where the soil pH is low. Excessive amounts of phosphorus fertilizers, flowing into stagnant and slowly flowing waters, cause the development of a large number of algae and other vegetation, which worsens the oxygen regime of water bodies and contributes to their overgrowing.

Nitrates are an integral part of all terrestrial and aquatic ecosystems, since the process of nitrification, leading to the formation of oxidized inorganic nitrogen compounds, is global in nature. At the same time, due to the large-scale use of nitrogen fertilizers, the supply of inorganic nitrogen compounds to plants increases. Excessive consumption of fertilizer nitrogen not only leads to the accumulation of nitrates in plants, but also contributes to the pollution of reservoirs and groundwater with fertilizer residues, as a result of which the area of ​​agricultural products contaminated with nitrates expands. However, the accumulation of nitrates in plants can occur not only from an excess of nitrogen fertilizers, but also from a lack of other types of fertilizers (phosphorus, potassium, etc.) by partially replacing the missing ions with nitrate ions during mineral nutrition, as well as when the enzyme activity of a number of plants decreases nitrate reductase, which converts nitrates into proteins.

In view of this, there is a clear difference between plant species and varieties in the accumulation and content of nitrates. Thus, the pumpkin, cabbage, and celery families are nitrate accumulators. The largest amount is found in leafy vegetables: parsley, dill, celery (Appendix 3), the smallest in tomatoes, eggplants, garlic, green peas, grapes, apples, etc. And there are strong differences in this regard between individual varieties. Thus, the carrot varieties “Chantenay” and “Pioneer” are distinguished by their low nitrate content, while “Nantes” and “Losinoostrovskaya” are distinguished by their high content. Winter cabbage varieties accumulate little nitrates compared to summer varieties.

The largest amount of nitrates is contained in the sucking and conducting organs of plants - roots, stems, petioles and leaf veins. In zucchini, cucumbers, etc. In fruits, nitrates decrease from the stalk to the apex (Appendix 4).

As a result of consuming foods containing high amounts of nitrates, a person may develop methemoglobinia. In this disease, the NO 3 - ion interacts with hemoglobin in the blood, oxidizing the iron included in hemoglobin to trivalent, and the resulting methemoglobin is not able to carry oxygen, and the person experiences oxygen deficiency and suffocates during physical exertion. In the gastrointestinal tract, excess amounts of nitrates under the influence of intestinal microflora are converted into toxic nitrites, and then they can be converted into nitrosamines - strong carcinogenic poisons that cause tumors. In this regard, when eating plants that store nitrates, it is important to dilute the nitrates and consume them in small doses. The nitrate content can be reduced by soaking, boiling products (if decoction is not used), and removing those parts that contain a large amount of nitrates.

The permissible norms of nitrates (according to WHO) are 5 mg (based on nitrate ion) per day per 1 kg of weight of an adult, i.e. with a weight of 50-60 kg it is 220-300 mg, and with a weight of 60-70 kg it is 300-350 mg.

An effect of synergy (intensification) and antagonism may also be observed, since factories pollute the biosphere in a complex manner.

Solving environmental problems:

1. Change the production flow chart (cessation or reduction of waste generation, maximum isolation of intermediate products and their use in cyclic processes).

2. Select the maximum number of elements from waste for other industries.

3. Neutralization of industrial emissions.

Methods for solving environmental problems:

Gaseous waste (homogeneous: sulfur and nitrogen oxides, organic substances in the form of gases - and heterogeneous: fog, dust, aerosols).

Sources of air pollution.

The atmosphere is divided into the troposphere (7-8 km from the surface of the earth). Above is the stratosphere - from 8-17 to 50-55 km. The air temperature here is higher, which is due to the presence of ozone here.

There are different forms of life in the troposphere. Therefore, the troposphere is referred to as the biosphere. Pollution entering the troposphere moves to higher layers very slowly. The main anthropogenic sources of pollution are:

thermal power plants operating on coal and emitting soot, ash and sulfur dioxide into the atmosphere;

metallurgical plants whose emissions contain soot, dust, iron oxide, sulfur dioxide, fluorides;

cement factories that emit huge amounts of dust;

large enterprises producing inorganic chemical products - sulfur dioxide, hydrogen fluoride, nitrogen oxides, chlorine, ozone;

plants for the production of cellulose, oil refining - gaseous waste (odorants);

petrochemical enterprises - serve as a source of hydrocarbons and organic compounds of other classes, such as amines, mercaptans, sulfides, aldehydes, ketones, alcohols, acids, etc.

exhaust gases from vehicles, as well as fuel evaporation processes - carbon monoxide, gaseous hydrocarbons and unchanged fuel components, high-boiling polycyclic aromatic hydrocarbons and soot, products of incomplete oxidation of fuel (for example, aldehydes), halogenated hydrocarbons, heavy metals and nitrogen oxides, the formation of which contribute to the processes occurring during fuel combustion;

forest fires, which release significant amounts of hydrocarbons and carbon oxides into the air.

Depending on the source and mechanism of formation, primary and secondary air pollutants are distinguished.

Primary pollutants are substances entering the air directly from stationary or mobile sources, while secondary pollutants are formed as a result of interactions between primary pollutants in the atmosphere and with substances present in the air (oxygen, ozone, ammonia, water) under the influence of ultraviolet radiation.

Most of the particulate matter and aerosols present in the air are secondary pollutants, which are often much more toxic than primary ones. Exhaust gases consist of various substances and, under the influence of solar radiation, can enter into photochemical reactions in the atmosphere, leading to the formation of toxic smog.

Criteria pollutants(for which special MPC criteria are introduced) - carbon monoxide, sulfur dioxide, nitrogen oxides, hydrocarbons, particulate matter and photochemical oxidants

One of the most harmful air pollutants is sulfur dioxide, which is involved in the formation of photochemical smog.

Although its average concentration in the air of large cities is not so high compared to other components, this oxide is considered the most dangerous to the health of city residents, causing respiratory diseases and general weakening of the body. When combined with other pollutants, it leads to a reduction in average life expectancy.

But the harm caused by sulfur dioxide cannot be attributed directly to this compound. The main culprit is sulfur trioxide SO 3, which is formed as a result of the reaction: 2SO 2 + O 2 = SO 3

The effect of SO 2 is stronger in the dark than in the light. What do you think is the reason for this?

You all know CO oxide. A person who inhales air with a CO content of only 0.1% for several hours absorbs so much of it that most of the hemoglobin (60%) binds to HbCO. This process is accompanied by headaches and decreased mental activity. In case of CO poisoning, a mixture of CO 2 and O 2 is used (the volume fraction of the former is 3 - 5%), called carbogen. Increased concentrations of these gases in the mixture make it possible to displace carbon monoxide from tissues in the blood.

High local concentrations of CO, even short-term ones, caused in large cities mainly by the operation of road transport, are so-called environmental traps. Carbon monoxide is a colorless, odorless gas, making it difficult to detect by our senses. However, the first symptoms of poisoning with it (the appearance of a headache) occur in a person who is in an environment with a CO concentration of 200 - 220 mg/m 3 in just 2 hours.

Thus, a person may find himself a victim of an environmental trap. Smokers are exposed to similar effects of CO.

Trace amounts of chemical elements in the atmosphere include highly toxic pollutants such as arsenic, beryllium, cadmium, lead, magnesium and chromium (usually present in the air as inorganic salts adsorbed on particulate matter). About 60 metals are present in coal combustion products and flue gases from thermal power plants. Every year a huge amount of lead enters the air basin. Metallic mercury and lead, as well as their organometallic compounds, are very toxic.

Accumulating in the atmosphere, pollutants interact with each other, hydrolyze and oxidize under the influence of moisture and oxygen, and also change their composition under the influence of radiation. Mixtures of various pollutants, the concentration of individual components in which is below the maximum permissible concentration, also pose a great danger. Together, such mixtures can pose a significant threat to all living things due to the cumulative effect. The duration of stay in the air of low-active compounds - permanent gases (freons and carbon dioxide) is long. Of the pesticides sprayed from airplanes, organophosphorus pesticides are especially toxic; when photolyzed in the atmosphere, products are formed that are even more toxic than the original compounds.

So-called abrasive particles, which include silica and asbestos, cause serious illness when they enter the body through inhalation.

Environmental smog is complex atmospheric pollution caused by stagnation of air masses in large cities with developed industry and a large number of transport. The origin of this English word is clear from the following diagram: SMOKE + FOG = smoke fog.

London-type smog is a combination of gaseous pollutants (mainly sulfur dioxide), dust particles and fog. It is especially characteristic of the polluted atmosphere over London, with the main source of air pollution being the products of burning coal and fuel oil. In December 1952, more than 4,000 people died in London during a smog that lasted about two weeks. Similar effects of smog were noted in London in 1873, 1882, 1891, 1948. This type of smog is observed only in autumn and winter (from October to February), when people’s well-being sharply worsened, the number of colds increased, etc.

Photochemical smog (Los Angeles type) - occurs as a result of photochemical reactions in the presence in the atmosphere of a high concentration of nitrogen oxides, hydrocarbons, ozone, intense solar radiation and calmness or very weak exchange of air masses in the ground layer. Unlike London-type smog, it was in sunny weather with significant concentrations of vehicle exhaust gases in the atmosphere that it was discovered in the 30s of the 20th century in Los Angeles, and now it is a common occurrence in large cities around the world.

Automobile internal combustion engines are the main source of this complex pollution. In Russia, motor vehicles emit 16.6 million tons of pollutants into the atmosphere every day. A particularly difficult environmental situation has developed in Moscow, St. Petersburg, Tomsk, Krasnodar. 30% of the diseases of city residents are directly related to air pollution from exhaust gases. Car engines emit more than 95% of carbon monoxide, about 65% of hydrocarbons and 30% of nitrogen oxides into the air of cities. The nature of the harmful impurities released depends on the type of engine, which is divided into gasoline and diesel. The main harmful impurities contained in exhaust gases are: nitrogen oxides, carbon oxides, various hydrocarbons, including carcinogenic benzopyrene, aldehydes, sulfur oxides. Gasoline engines, in addition, emit products containing lead and chlorine, and diesel engines emit significant amounts of soot and soot particles.

1. Pipe dispersion method.

2. Filters.

3. Catalytic gas purification:

S-> S0 2 -> S0 3 ->H 2 SO 4

CO -> CH 4

4. Chemical cleaning methods:

a) absorption - absorption of liquid gases at low temperature and high pressure (water, organic absorbents, potassium permanganate, potash solution, mercaptoethanol); b) adsorption (activated carbon, silica gel, cialites).

Wastewater treatment from chemical plants.

The hydrosphere serves as a natural accumulator for most pollutants entering the atmosphere or lithosphere. This is due to the high dissolving power of water, the water cycle in nature, and also to the fact that reservoirs are the final destination on the path of various wastewaters.

As a result of the discharge of untreated wastewater by enterprises, municipal and agricultural facilities, the natural properties of water change due to an increase in harmful impurities of inorganic and organic nature. TO inorganic impurities include heavy metals, acids, alkalis, mineral salts and fertilizers with biogenic elements (nitrogen, phosphorus, carbon, silicon). Among organic impurities emit easily oxidized (organic substances from wastewater from food enterprises and other biologically soft substances) and difficult to oxidize and therefore difficult to remove from water (oil and its products, organic residues, biologically active substances, pesticides, etc.).

Changes in the physical parameters of water are possible as a result of three types of impurities entering it: mechanical ( solid insoluble particles: sand, clay, slag, ore inclusions); thermal ( discharge of heated water from thermal power plants, nuclear power plants and industrial enterprises); radioactive ( products of enterprises for the extraction of radioactive raw materials, enrichment factories, nuclear power plants, etc.) - The influence of mechanical and radioactive impurities on water quality is clear, and thermal impurities can lead to exothermic chemical reactions of components dissolved or suspended in water, and the synthesis of even more dangerous ones substances.

Changes in the properties of water occur as a result of an increase in the number of microorganisms, plants and animals from external sources: bacteria, algae, fungi, worms, etc. (discharge of domestic wastewater and waste from some enterprises). Their vital activity can be greatly activated by physical pollution (especially thermal pollution).

Thermal pollution causes an intensification of the vital processes of aquatic organisms, which upsets the balance of the ecosystem.

Mineral salts are dangerous for single-celled organisms that exchange with the external environment osmotically.

Suspended particles reduce water transparency, reduce photosynthesis of aquatic plants and aeration of the aquatic environment, contribute to siltation of the bottom in areas with low current speed, and have an adverse effect on the life of aquatic filter-feeding organisms. Various pollutants can be adsorbed on suspended particles; settling to the bottom, they can become a source of secondary water pollution.

Water pollution with heavy metals not only causes environmental harm, but also causes significant economic damage. Sources of water pollution with heavy metals are electroplating shops, mining enterprises, ferrous and non-ferrous metallurgy.

When water is contaminated with petroleum products, a film forms on the surface, preventing the gas exchange of water with the atmosphere. Other pollutants accumulate in it, as well as in the emulsion of heavy fractions; in addition, the oil products themselves accumulate in aquatic organisms. The main sources of water pollution with oil products are water transport and surface runoff from urban areas. Pollution of the aquatic environment with nutrients leads to eutrophication of water bodies.

Organic substances - dyes, phenols, surfactants, dioxins, pesticides, etc. create a danger of a toxicological situation in the reservoir. Dioxins are especially toxic and persistent in the environment. These are two groups of chlorine-containing organic compounds related to dibenzodioxins and dibenzofurans. One of them, 2, 3, 7, 8-tetrachlorodibenzodioxin (2, 3, 7, 8 - TCDD), is the most toxic compound known to science. The toxic effect of various dioxins is similar, but differs in intensity. Dioxins accumulate in the environment and their concentration is increasing.

If we conditionally dissect the water mass with a vertical plane, we can identify areas of different reactivity: the surface film, the main water mass and bottom sediment.

Bottom sediment and surface film are areas where pollutants are concentrated. Water-insoluble compounds settle to the bottom, and the sediment is a good sorbent for many substances.

Non-degradable contaminants may enter the water. But they are able to react with other chemical compounds, forming stable end products that accumulate in biological objects (plankton, fish, etc.) and enter the human body through the food chain.

When choosing a place to take a water sample, all circumstances that may affect the composition of the sample taken are taken into account.

There are two main samples: single and average. A single sample is obtained by collecting the required volume of water at a time. The average sample is obtained by mixing equal volumes of samples taken at regular intervals. The smaller the intervals between its individual component samples, the more accurate the average sample.

Water for analysis is taken into a clean container, having first rinsed it 2-3 times with the water being tested. From open reservoirs, samples are taken in the river fairway from a depth of 50 cm. A bottle with a load is lowered to a depth, after which the stopper is opened using a holder attached to it. It is better to use special devices for this purpose - bathometers, which allow the use of dishes of different shapes and capacities. The bathometer consists of a clamp that tightly grips the container and a device for opening the cork at the desired depth.

When a sample sits for a long time, significant changes in the composition of the water can occur; therefore, if it is impossible to begin analyzing the water immediately after sampling or 12 hours after sampling, it is preserved to stabilize the chemical composition. There is no universal preservative.

There are 3 groups of indicators that determine water quality (we will analyze it in detail and experimentally at the workshop):

A - indicators characterizing organoleptic properties;

B - indicators characterizing the chemical composition of water;

B - indicators characterizing the epidemic safety of water.

In order for a person to use water for drinking, it is first purified.

Water purification stages:

Advocacy

Filtration

Disinfection

Gases used for disinfection are chlorine and ozone.

Chemical and biological water purification is also used. Septic tanks are colonized with chlorella. This single-celled plant, rapidly multiplying, absorbs CO 2 and some harmful substances from the water. As a result, the water is purified, and chlorella is used as livestock feed.

Preparation of drinking water.

River, lake or reservoir - separation of large impurities - preliminary chlorination - precipitation of flocs - sedimentation of impurities by settling - filtering through sand - chlorination - additional treatment - into the city water supply system.

To survive, a person needs about 1.5 liters of water per day. But each citizen annually spends up to 600 liters of water for household needs. Industry consumes a lot of water.

For example, to produce 1 kg of paper, 20,000 liters of fresh water are required. The main water pollutant is agriculture. To increase the yield, various fertilizers are applied to the field. This can lead to increased concentrations of various compounds in food and drinking water, which is hazardous to health. Among other pollutants, the most noticeable are oil and petroleum products that enter natural waters during the operation of oil tankers.

According to WHO, 80% of all infectious diseases in the world are associated with unsatisfactory quality of drinking water and violations of sanitary and hygienic water supply standards. In the world, 2 billion people have chronic diseases due to the use of contaminated water (Appendix 2, Table 1).

According to UN experts, up to 80% of chemical compounds sooner or later end up in water sources. Every year, more than 420 km 3 of wastewater is discharged around the world, which makes about 7 thousand km 3 of water unusable. The chemical composition of water poses a serious danger to public health. In nature, it is never found in the form of a chemically pure compound. It constantly carries a large number of different elements and compounds, the ratio of which is determined by the conditions of water formation and the composition of hydrogen rocks.

Methods of water purification in everyday life.

The simplest and most accessible method for everyone is upholding tap water. In this case, residual free chlorine evaporates. Under the influence of gravitational forces, precipitation of relatively large suspension and colloidal particles in suspension occurs. The sediment may turn yellow. What do you think this will indicate? (precipitation of Fe (OH) 3).

Boiling.

The main purpose of this method is water disinfection. As a result of thermal exposure, viruses and bacteria die. In addition, water is degassed - the removal of all gases dissolved in it, including useful ones. Which ones? (O 2, CO 2). These gases improve the organoleptic properties of water.

Explain why boiled water is tasteless and of little benefit to intestinal flora?

Method freezing water.

Used much less frequently. Based on the difference between the freezing temperatures of pure water and brines (a solution of mineral salts). First, pure water freezes, and salts are concentrated in the remaining volume. There is an opinion that such water has healing properties due to the special structure of water clusters - groups of mutually oriented water molecules.

Cleaning of drains

The cleaning technology includes several stages.

Table 2. Wastewater treatment.

First, wastewater is purified from insoluble impurities. Large objects are removed by filtering (remember what filtration is) water through grates and meshes.

The water then goes into a settling tank, where small particles gradually settle.

To remove dissolved organic substances (NH 3 and ammonium cations), they are oxidized with the help of bacteria. The process proceeds more intensively under aeration conditions. What are aerobic conditions? Aeration? (saturation of water with air oxygen)

Nitrates are converted into nitrogen gas using special microorganisms. Phosphorus compounds are precipitated in the form of poorly soluble calcium orthophosphate.

Then carry out:

repeated settling;

absorption of remaining impurities by activated carbon;

disinfection.

Only after this can water be returned to natural reservoirs.

The discharge of wastewater into the environment does not stop. Almost 1/3 ends up in natural water bodies without any treatment. This is not only dangerous for the life of organisms, but also leads to a deterioration in the quality of drinking water. Preventing water pollution remains one of the most important tasks for protecting the environment and preserving human health.

1. Filtration.

2. Sedimentation and filtration.

3. Flotation.

4. Distillation.

5. Ion exchange.

6. Biochemical (for oil).

7. Microorganisms for waters with a high content of nitrogen, phosphorus and surfactants.

8. Creation of water circulation cycles.

Diseases arising from the toxic effects of chemical elements and substances in drinking water

Table 1.

Solid waste (unreacted raw materials, filters and catalysts).

1. Extraction of useful components by extraction (noble metals from spent catalysts).

2. Thermal methods.

3. Sanitary backfills.

4. Burial in the ocean.

In the 19th and 20th centuries, human interaction with the environment, or anthropogenic activities, takes place in the form of large-scale material production.