Introduction

Sources of chemical pollution

Energy facilities are the sources of the largest volumes of chemical pollution

Transport as a source of chemical pollution

Chemical industry as a source of pollution

Impact on the ecosystem

6. Fight against losses during transportation (prevention of accidents of gas and oil pipelines).

Water pollution control

Recycling.

Conclusion

Introduction

The development of modern industry and the service sector, as well as the expanding use of the biosphere and its resources, leads to an increasing human intervention in the material processes taking place on the planet. The planned and conscious changes in the material composition (quality) of the environment related to this are aimed at improving human living conditions in technical and socio-economic aspects. In recent decades, in the process of developing technology, the danger of unintended side effects on humans, living and inanimate nature has been ignored. This can perhaps be explained by the fact that it was previously believed that nature has an unlimited ability to compensate for human impact, although irreversible environmental changes have been known for centuries, for example, deforestation followed by soil erosion. Today, unforeseen impacts on easily vulnerable areas of the ecosphere as a result of active human activity cannot be ruled out.

Man has created for himself a habitat filled with synthetic substances. Their impact on humans, other organisms and the environment is often unknown and is often detected when significant damage has already been done or under emergency circumstances, for example, it suddenly turns out that during combustion a completely neutral substance or material forms toxic compounds.

New drinks, cosmetics, foodstuffs, medicines, household items offered by advertising on a daily basis necessarily include chemical components synthesized by man. The degree of ignorance of the toxicity of all these substances can be judged from the data in Table. 1.

The book "Ecological Problems" (p. 36) gives the following facts:

“About 5 thousand substances are now produced on a mass scale, and about 13 thousand substances on a scale of more than 500 tons / year. The number of substances offered on the market on a noticeable scale, from 50 thousand items in 1980, has increased to 100 thousand items at the present time. Of the 1338 substances produced on a large scale in the countries of the Organization for Economic Cooperation and Development (OECD), only 147 have some data on their danger or safety (Losev, 1989; TheWord…, 1992). According to (Meadows…, 1994), out of 65 thousand chemical substances in commercial circulation, less than 1% have toxicological characteristics.”

Although exposure to chemicals is costly: characterization of a single substance requires 64 months and $575,000, and studies of chronic toxicity and carcinogenicity require an additional $1.3 million (p. 36); little work is being done in this area.

Currently, for a number of reasons, problems remain unresolved in assessing the toxicity of chemical products to humans, and in more towards environment. exhaustive research

Scope of information available	Industrial chemicals with production >500 t/y½<500 т/год½ Объем неизв			Food additives	Medicines fiziol. active in-va	Cosmetic ingredients		Pesticides, inert additives
Full, %	0	0	0	5	18		2	10
Incomplete, %	11	12	10	14	18		14	24
Not enough information, %	11	12	8	1	3		10	2
Very little information, %	0	0	0	34	36		18	26
No information, %	78	76	82	46	25		56	38
100	100	100	100	100		100	100
Number of chemical product studies	12860	13911	21752	8627	1815		3410	3350

impacts of substances can only be realized after complete information on the exposure (acting dose) of each chemical is obtained.

In the course of their economic activity, a person produces various substances. All produced substances using both renewable and non-renewable resources can be divided into four types:

* initial substances (raw materials);

* intermediate substances (arising or used in the production process);

* final product;

* by-product (waste).

Waste occurs at all stages of obtaining the final product, and any final product after consumption or use becomes waste, so the final product can be called deferred waste. All wastes enter the environment and are included in the biogeochemical cycle of substances in the biosphere. Many chemical products are included by man in the biogeochemical cycle on a scale much greater than the natural cycle. Some substances sent by man into the environment were previously absent in the biosphere (for example, chlorofluorocarbons, plutonium, plastics, etc.), so natural processes cannot cope with these substances for a long time. The result is enormous damage to organisms.

table 2. Sources of emission (release) of harmful substances (%) in 1986 and forecast for 1998 (on the example of Germany).

SO2		NO x (NO 2)		co		Dust		Volatile organic compounds
Industry (sector of the national economy)	1996	1998	1996	1998	1996	1998	1996	1998	1996	1998
Total	100	100	100	100	100	100	100	100	100	100
Processes	4,3	7,9	0,8	0,4	11,9	15,0	57,7	59,1	4,6	7,0
Power consumption	95,7	92,1	99,2	99,6	88,1	85,0	42,3	40,9	56,4	60,4
transport, except urban a)	1,8	3,3	8,3	10,6	3,2	3,4	3,1	2,7	3,0	3,9
· urban transport	2,8	7,5	52,4	64,0	70,7	63,6	10,3	12,9	48,5	49,9
· household	5,8	9,6	3,1	3,5	9,0	10,5	6,7	6,1	3,0	3,7
small consumers b)	4,4	6,4	1,7	,1,8	1,5	2,0	1,6	1,3	0,5	0,7
processing plants and mines c)	12,6	14,7	7,1	7,0	2,9	4,3	4,1	4,6	0,8	1,1
Other processing industries c), d)	5,7	14,5	2,0	2,1	0,3	0,5	0,9	1,3	0,1	0,3
Electric and thermal power plants e)	62,6	36,1	24,6	10,6	0,5	0,7	15,6	12,0	0,5	0,8

a) Construction, agriculture and forestry, military, rail and water transport, air communications.

b) Including military services.

c) Industry: other areas of processing, enterprises and mining, processes (industrial only).

d) Oil refineries, coke batteries, briquetting.

e) For industrial power plants, only energy production.

From Table. 2 (p. 109) it can be seen that the largest amount of waste is associated with the production of energy, on the consumption of which all

Table 3 Air emissions from a 1000 MW/year power plant (in tons).

economic activity. Due to the burning of fossil fuels for energy purposes, there is now a massive flow of reducing gases into the atmosphere. In table. 3 ( p. 38) shows data on emissions of various gases from the combustion of various types of fossil fuels. For 20 years, from 1970 to 1990, the world burned 450 billion barrels of oil, 90 billion tons of coal, 11 trillion. cube m of gas ( p. 38).

Pollution and waste from energy facilities are divided into two streams: one causes global changes, and the other - regional and local. Global pollutants enter the atmosphere, and due to their volume

Table 4. Changes in the concentration of certain gas components in the atmosphere.

number of greenhouse gases (Table 4, see , p. 40). From this table it can be seen that the concentration of small gas components of the atmosphere changes in the accumulation, gases appeared in the atmosphere that were practically absent in it before - chlorofluorocarbons. The consequences of the accumulation of global pollutants in the atmosphere are:

* Greenhouse effect;

* destruction of the ozone layer;

* acid precipitation.

The second place in terms of environmental pollution is occupied by transport, especially automobiles. In 1992, the world car park was 600 million units and, if the growth trend continues, by 2015 it could reach 1.5 billion units (p. 41). The combustion of fossil fuels by vehicles increases the concentrations of CO, NO x , CO 2 , hydrocarbons, heavy metals and particulate matter in the atmosphere, it also produces solid waste (tires and the car itself after failure) and liquid waste (waste oils, washing, etc. .). Cars account for 25% of the fuel burned. During operation, equal to 6 years, one average car emits into the atmosphere: 9 tons of CO 2 , 0.9 tons of CO, 0.25 tons of NO x and 80 kg of hydrocarbons.

Of course, compared with energy and transport, global pollution through the chemical industry is small, but this is also a fairly tangible local impact. Most organic intermediates and end products used or produced in the chemical industry are made from a limited number of basic petrochemicals. During the processing of crude oil or natural gas, various stages of the process, such as distillation, catalytic cracking, sulfur removal and alkylation, generate both gaseous and dissolved in water and discharged into the sewer. These include residues and waste from technological processes that cannot be further processed.

Gaseous emissions from distillation and cracking plants during oil refining mainly contain hydrocarbons, carbon monoxide, hydrogen sulfide, ammonia and nitrogen oxides. The part of these substances that can be collected in gas collectors before venting into the atmosphere is burned in flares, resulting in hydrocarbon combustion products, carbon monoxide, nitrogen oxides and sulfur dioxide. When burning acidic alkylation products, hydrogen fluoride is released into the atmosphere. There are also uncontrolled emissions caused by various leaks, deficiencies in equipment maintenance, process disturbances, accidents, as well as the evaporation of gaseous substances from the process water supply system and from wastewater.

Of all types of chemical industries, the greatest pollution is caused by those where varnishes and paints are made or used. This is due to the fact that varnishes and paints are often made on the basis of alkyd and other polymeric materials, as well as nitro-varnishes, they usually contain a large percentage of solvent. Emissions of anthropogenic organic substances in industries associated with the use of varnishes and paints is 350 thousand tons per year, the rest of the chemical industry as a whole emit 170 thousand tons per year (, p. 147).

Environmental impact of chemicals

Let us consider in more detail the impact of chemicals on the environment. Ecotoxicology deals with the study of the influence of anthropogenic chemicals on biological objects of the environment. The task of ecotoxicology is to study the impact of chemical factors on species, living communities, abiotic components of ecosystems and on their functions.

Under the harmful effects applied to the corresponding system, in ecotoxicology understand:

clear changes in the usual fluctuations in population size;

long-term or irreversible changes in the state of the ecosystem.

Effects on Individuals and Populations

Any exposure starts with a toxic threshold, below which no effect of the substance is detected (NOEC - concentration, below which no effect is observed). It corresponds to the concept of an experimentally determined concentration threshold (LOEC - the minimum concentration at which the effect of a substance is observed). A third parameter is also used: MATC - the maximum permissible concentration of a harmful substance (in Russia, the term MPC is adopted - “maximum permissible concentration”). MPC is found by calculation, and its value should be between NOEC and LOEC. Determination of this value facilitates the assessment of the risk of exposure of the relevant substances to sensitive organisms ( p. 188).

Chemical substances, depending on the properties and structure, affect organisms in different ways.

Molecular biological effects.

Many chemicals interact with the body's enzymes, changing their structure. Since enzymes catalyze thousands of chemical reactions, it becomes clear why any change in their structure profoundly affects their specificity and regulatory properties.

Example: cyanides block the respiratory enzyme - cytochrome c-oxidase; Ca 2+ cations inhibit the activity of riboflavin kitase, which is a phosphate carrier to riboflavin in animal cells.

Disorders of metabolism and regulatory processes in the cell.

Cell metabolism can be disrupted by chemicals. Reacting with hormones and other regulatory systems, chemicals cause uncontrolled transformations and change the genetic code.

Example: violation of the reactions of oxidative breakdown of carbohydrates caused by toxic metals, especially copper and arsenic compounds; pentachlorophenol (PCP), triethyl lead, triethyl zinc and 2,4-dinitrophenol break the chain of chemical processes of respiration at the stage of the oxidative phosphorylation reaction; lidan, cobalt and selenium compounds disrupt the process of splitting fatty acids; Organochlorine pesticides and polychlorinated biphenyls (PCBPs) cause thyroid disorders.

Mutagenic and carcinogenic effects.

Substances such as DDT, PCBFs and polyaromatic hydrocarbons (PAHs) have the potential to be mutagenic and carcinogenic. Their dangerous effects on humans and animals are manifested as a result of prolonged contact with these substances contained in the air and food products. According to data obtained on the basis of experiments with animals, the carcinogenic effect is carried out as a result of a two-stage mechanism:

4. Impact on the behavior of organisms.

Table 5 Examples of initiators and promoters of carcinogenesis (p. 194).

Initiators		promoters
Chemical compounds	Biological properties	Chemical compounds	Biological properties
PAHs (polycondensed aromatic hydrocarbons), nitrosamines	Carcinogenic	Croton oil	Itself is not carcinogenic.
N-nitroso-N-nitro-N-methylguanidine	Exposure before exposure to the promoter	Phenobarbital	The action occurs after the appearance of the initiator
Dimethylnitrosamine Diethylnitrosamine	A single injection is enough	DDT, PCBF TCDD (tetrachlorodibenzodioxin)	Long term exposure required
N-nitroso-N-methylurea	The influence is irreversible and additive	Chloroform	Initially, the action is reversible and not additive.
Urethane	There is no threshold concentration	Saccharin (questionable)	Threshold concentration likely dependent on dose exposure time
1,2-Dimethylhydrazine	Mutagenic action	Cyclamate	No mutagenic effect

	Substance introduction Threshold of exposure
immediately - a few days	Conduct violations (neurological and endocrine, chymotaxis, photogeotaxis, balance/orientation, flight, motivation/learning ability)	Biochemical reactions (enzymatic and metabolic activity, synthesis of amino acids and steroid hormones, membrane changes, DNA mutations) ¾¾¾¾¾¾¾¾¾¾¾¾¾
	Physiological (oxygen consumption, osmotic and ionic regulation, digestion and excretion of food, photosynthesis, nitrogen fixation)	Morphological changes (changes in cells and tissues, the formation of tumors, anatomical changes)
hours - weeks	¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾
days - months	Changing the Individual Life Cycle (embryonic development, growth rate, reproduction, ability to regenerate)
months - years	Population changes (decrease in the number of individuals, changes in age structure, changes in genetic material)
months - decades	Environmental consequences (dynamic changes in biocenoses / ecosystems, their structure and function)

Rice. 1. Impacts on biological systems as they become more complex (p. 201).

“genotoxic initiation”,

“epigenetic promotion”.

Initiators in the process of interaction with DNA, they cause irreversible somatic mutations, and a very small dose of the initiator is sufficient, it is assumed that for this effect there are no concentration thresholds below which it does not manifest itself.

Directed destruction of certain species of plants and animals.

Example: aldehyde, fungicidal, acaricidal, herbicidal, insecticidal measures, especially in urbanized ecosystems

A widespread decrease in the species diversity of organisms.

Example: use of pesticides and fertilizers in agricultural ecosystems.

Massive pollution.

Example: pollution of coasts and river extuaries with oil from tanker accidents.

Constant pollution of biotopes

Example: eutherification of rivers and lakes as a result of the ingress of significant amounts of dissolved and bound compounds of nitrogen and phosphorus into them.

Deep biotope changes

Example: salinization of freshwater biotopes; “modern deterioration of the state of forests.

Complete destruction of the ecosystem as a result of the loss of an integral intact structure (biotope) and its functions (biocenosis).

Example: The destruction of mangrove forests as a result of the use of herbicides as chemical weapons in the Vietnam War.

Fig.2. Scheme of possible consequences of the impact of chemical products on ecosystems.

promoters enhance the action of the initiator, and their own effect on

the organism is reversible for some time.

Additive impact- summation (addition) of individual impacts.

Table 5 lists some of the initiators and promoters and their properties.

Violation of the behavior of organisms is a consequence of the total impact on biological and physiological processes.

Example: Significantly lower concentrations than the LD 50 (lethal dose at 50% mortality) were found to produce a clear change in behavior due to exposure to chemicals.

Different organisms have different sensitivity to chemicals, so the time of manifestation of certain actions of chemicals for different biosystems is different (see Fig. 1).

Impact on the ecosystem

Under the influence of chemicals, the following ecosystem parameters change:

* population density;

* dominant structure;

* species diversity;

* abundance of biomass;

* spatial distribution of organisms;

* reproductive functions.

Possible consequences and forms of harmful effects of chemicals on the ecosystem can be classified according to Fig. 2 (p. 184).

Measures taken to minimize the risk of using chemical products

In order to minimize the risk of using chemical products, in accordance with the level of our knowledge of this problem in the EU countries, in 1982 the so-called “Chemical Products Law” was enacted. In the process of verifying its implementation, over the course of several years, measures were taken to optimize technologies, biological and physico-chemical tests, as well as to clarify the terminology, standard substances and sampling methods. The Chemical Law establishes the rules for the admission to the market of all new chemical products.

Technical measures used to prevent the danger of industrial emissions

To reduce and reduce the release of chemicals from industrial enterprises, the following measures should be taken:

Let's take a closer look at the last two points.

Water pollution control

Understanding the need for regulated water supply and wastewater treatment arose a very long time ago. Even in ancient Rome, aqueducts were built to supply fresh water and “Cloacamaxima” - a sewer network. sump basin and thereby preventing clogging of the sewerage and the formation of decay products (“Dortmund wells” and “Emsky wells”).

Another method of neutralizing wastewater was their purification using irrigation fields, i.e., the discharge of wastewater to specially prepared fields. However, only in the middle of the last century did the development of wastewater treatment methods and the systematic construction of sewer networks in cities begin.

First, mechanical cleaning plants were created. The essence of this purification was the sedimentation of solid particles in the wastewater to the bottom, seepage through the sandy soil, the wastewater was filtered and clarified. And only after the discovery in 1914 of Biological (live) sludge

Table 6. Physico-chemical wastewater treatment (p. 153).

Table 7. Limit values for the concentration of pollutants in wastewater from oil refineries sent for biological treatment ( p.144).

Table 8. Average characteristics of seepage waters from storages (dumps) of municipal household waste (6-8 years after storage) ( p.165).

pH value	6,5 - 9,0
Dry residue	20000 ml/l
Insoluble substances	2000 mg/l
Electrical conductivity (20 o C)	20000 µS/cm
Inorganic components
Compounds of alkali and alkaline earth metals (per metal)	8000 mg/l
Heavy metal compounds (per metal)	10 mg/l
Iron compounds (total Fe)	1000 mg/l
NH4	1000 mg/l
SO 2-	1500 mg/l
HCO3	10000 mg/l
Organic Ingredients
BOD (biochemical oxygen demand for 5 days)	4000 mg/l
COD (chemical oxygen demand)	6000 mg/l
Phenol	50 mg/l
Detergent	50 mg/l
Substances extractable with methylene chloride	600 mg/l
Organic acids distilled off with water vapor (calculated as acetic acid)	1000 mg/l

it became possible to develop modern technologies for wastewater treatment, including the return (recycle) of biological sludge to a new portion of wastewater and simultaneous aeration of the suspension. All wastewater treatment methods developed in subsequent years and up to the present do not contain any essentially new solutions, but only optimize the previously developed method, limited to various combinations of known technological process stages. The exception is physico-chemical treatment methods, which use physical methods and chemical reactions specially selected to remove substances contained in wastewater (Table 6).

Wastewater from enterprises (for example, oil refineries) is first subjected to physical and chemical treatment, and then biological. The content of harmful substances in wastewater entering biological treatment should not exceed certain values (Table 7).

Recycling.

When developing an environmentally compatible waste management system, the following (in order of importance) main tasks are set:

Types of waste disposal:

* warehousing;

* incineration;

* composting (not applicable for waste containing toxic substances);

* pyrolysis.

Table 9. Emission of harmful substances from waste incineration plants (mg/l) (p.158).

Table 10. Average content of metals in dusty particles of incinerator smoke (10 samples, average dust content in flue gases 88 mg/m 3) (p.159).

Table 11 Differences between thermolysis and pyrolysis of organic waste (p.171).

waste incineration	Waste pyrolysis
Mandatory high temperature	Rather relatively low temperature (450 o C)
Excess air required (resp. oxygen)	Lack of oxygen (resp. air)
Heat input directly due to the released heat of reaction	Heat input mostly through heat exchangers
Oxidizing conditions, metals oxidize	Reducing conditions, metals do not oxidize
Main reaction products: CO 2 , H 2 O, ash, slag	Main reaction products: H 2 , C n H m , CO, solid carbon residues
Gaseous harmful substances: SO2, SO 3 , NO x , HCl, HF, heavy metals, dust	Gaseous harmful substances: H 2 S, HCN, NH 3 , HCl, HF, phenols, resins, Hg, dust
Large volumes of gas (proportion of air)	Small volumes of gases
Ash is sintered into slag, leaving moisture	No fusion and sintering processes, moisture loss
Pre-grinding and uniformity of crushing are not necessary, but favorable	Pre-crushing and crushing uniformity are essential
Liquid and pasty wastes are generally untreated	Liquid and pasty wastes are in principle treated
Profitability of production is achieved with a population of about 1 million	The economy of production is likely to be ensured with a population of about a million

The most common now is the storage of waste. Approximately 2/3 of all household and industrial waste and 90% of inert waste are stored in landfills. Such storage facilities occupy large areas, are sources of noise, dust and gases resulting from chemical and anaerobic biological reactions in the stratum, as well as sources of groundwater pollution as a result of the formation of seepage water in open landfills (Table 8).

It follows that the storage of waste cannot be a satisfactory method of their disposal, and other methods must be used.

Currently, up to 50% of all waste in developed countries is incinerated. The advantages of the incineration method are the significant reduction in waste volume and the effective destruction of combustible materials, including organic compounds. Incineration residues - slag and ash - make up only 10% of the original volume and 30% of the mass of the burned materials. But with incomplete combustion, numerous harmful substances can enter the environment (Tables 9 and 10). To reduce the emission of organic substances, it is necessary to use fume treatment devices.

Pyrolysis is the decomposition of chemical compounds at high temperatures in the absence of oxygen, as a result of which their combustion becomes impossible. In table. 11 shows the differences in the processes of incineration (thermolysis) and pyrolysis of waste based on a comparison of these two methods. Although pyrolysis has many advantages, it also has significant disadvantages: wastewater coming from pyrolysis plants is heavily polluted with organic substances (phenols, chlorinated hydrocarbons, etc.), and from dumps of solid residues of pyrolysis (pyrolysis coke) under the action of rains, washing out harmful substances; in solid pyrolysis products, in addition, high concentrations of polycondensed and chlorinated hydrocarbons were found. In this regard, pyrolysis cannot be considered an environmentally friendly method of waste processing.

Man in the course of his activities produces a huge amount of chemicals that adversely affect the environment. But at the moment he does not have such a technology that would make human activity absolutely waste-free.

Conclusion

So, I have considered some aspects of chemical pollution of the environment. These are far from all aspects of this huge problem and only a small part of the possibilities for solving it. In order not to completely destroy the habitat of its habitat and the habitat of all other forms of life, a person must be very careful about the environment. And this means that strict control of direct and indirect production of chemicals is necessary, a comprehensive study of this problem, an objective assessment of the impact of chemical products on the environment, the search for and application of methods to minimize the harmful effects of chemicals on the environment.

Bibliography

1. Ecological chemistry: Per. with him. / Ed. F. Korte. - M.: Mir, 1996. - 396 p., ill.

2. Ecological problems: what is happening, who is to blame and what to do?: Textbook / Ed. Prof. V. I. Danilov - Danilyan. - M.: Publishing house of MNEPU, 1997. - 332 p.

3. Nebel B. Science of the environment: How the world works: In 2 vols. T. 1.2. Per. from English - M .: Mir, 1993. - p., ill.

4. Revel P., Revel Ch. Our habitat: In 4 books. Book. 2. Pollution of water and air: Translated from English. - M.: Mir, 1995. - p., ill.

The problem of chemical pollution of the planet is one of the global and urgent environmental problems. The ecological part of chemistry investigates the impact of substances on the environment (air, water, solid bark, living organisms).
Let's look at some of these issues:
acid rain
Greenhouse effect
General air pollution
The ozone hole
Nuclear pollution.

Greenhouse effect

The greenhouse effect is a process in the atmosphere in which incident visible light is transmitted and infrared is absorbed, which increases the temperature at the Earth's surface and harms all nature. Pollution is an excess of carbon dioxide.

This concept was first formulated in 1863. Tydall. In 1896 S. Arrhenius showed that carbon dioxide increases the temperature of the atmosphere by 5 0 C. In the 70s of the 20th century, it was proved that other gases also give a greenhouse effect: carbon dioxide - 50-60%, methane - 20%, nitrogen oxides - 5 %.

A stream of visible rays enters the Earth's surface, they pass through greenhouse gases without changing, and when they meet the Earth, part of them is transformed into long-wave infrared rays. These rays are blocked by greenhouse gases and heat remains on the Earth.

In 1890 - the average temperature of the planet is 14.5 0 C, in 1980 - 15.2 0 C. The danger is in the growth trend. According to forecasts for 2030-50, it will still grow by 1.5-4.5 0 С.

Consequences:

Negative: the melting of eternal snows and the rise of the ocean level by 1.5 m. flooding of the most productive territories, unstable weather, acceleration of the rate of extinction of animals and plants, thawing of permafrost, which will lead to the destruction of buildings built on piles.

Positive: warm winters in the northern regions of our country, some advantages for farming.

Destruction of the ozone layer

Depletion of the ozone layer is the process of reducing the amount of ozone in the atmosphere at an altitude of about 25 km (in the stratosphere). There, ozone and oxygen mutually transform into each other (3O2 ↔ 2O3) under the influence of ultraviolet radiation from the Sun and do not let this radiation reach the Earth's surface, which saves the entire living world from extinction. The formation of "ozone holes" is caused by freons and nitrous gases, which absorb UV radiation instead of ozone and disturb the balance.

acid rain

Acid rain is precipitation that contains acids due to the absorption of sulfur dioxide and nitrogen oxides by clouds. The source of pollution is industrial emissions of gases, engines of supersonic aircraft. This leads to damage to deciduous plants, corrosion of metals, acidification of soils and water.

The acidity of natural reservoirs and precipitation is normal if the pH is 5.6 (due to CO 2 dissolved in water)

Acid precipitation is any precipitation that is acidic. They were first registered in England in 1907-1908. Now there are precipitations with a pH of 2.2-2.3.

Sources of acid precipitation: acid oxides: SO 2 , NO 2

The mechanism of acid precipitation formation: gases + water vapor form solutions of acids with pH< 7

Sulfur compounds are released into the atmosphere:
a) in a natural way i.e. biological processes of destruction, the action of anaerobic bacteria of wetlands, volcanic activity.
b) anthropogenic - 59-60% of the total amount of emissions into the atmosphere, processing of various types of fuel, the work of metallurgy enterprises, cement work, the production of sulfuric acid, etc.

2 H 2 S + 3O 2 \u003d 2H 2 O + 2SO 2

Nitrogen oxides enter the atmosphere:
a) naturally - by a thunderstorm, or under the action of soil bacteria;
b) anthropogenic - due to the activity of vehicles, thermal power plants, the production of mineral fertilizers, nitric acid, nitro compounds, blasting.

2NO + O 2 \u003d 2NO 2

When nitric oxide +4 is dissolved in water, two acids are formed - nitric and nitrous, when nitric oxide +4 is oxidized and interacts with water, nitric acid is formed.

2NO 2 + H 2 O \u003d HNO 3 + HNO 2

4NO 2 + 2H 2 O + O 2 \u003d 4HNO 3

General air pollution

In addition to the listed oxides of nitrogen and sulfur, other gases are also emitted into the atmosphere.

Carbon forms two oxides: carbon dioxide and carbon monoxide.

Carbon monoxide is poison. It is formed during the incomplete combustion of fuel.

The main suppliers of harmful gases are cars.

MPC CO - 9 -10 μg / m 3

There are many other types of environmental pollution, such as sewage with toxic waste, highly persistent substances (pesticides, heavy metals, polyethylene, etc.), industrial smoke and dust, road transport, oil tankers.

Of course, you can buy a manual and read about the chemical foundations of biology there ... Or go to all the teacher's lectures and learn all the information from there. But if you're short on time and don't feel like spending money, here's a brief and basic introduction to this strange discipline found in some universities.

What is chemical ecology?

Chemical ecology is a branch of ecology that deals with the study of the consequences of the direct and side effects of chemicals on the environment and the likely ways to reduce their negative impact.

This is the main term. However, there are others. For example, English literature understands chemical ecology as the study of chem. interactions between species in an ecosystem.

Chemist Rakov E.G. wants chemical ecology to be understood much more broadly, proposing to include in it the study of any chemical processes occurring in ecosystems (including the circulation of substances).

Chemical pollution of the environment

Humanity has always been connected with the world around it. However, the detrimental impact of man on nature has acquired such a huge scale with the development of a highly industrialized society.

What significance does this have for us? Most directly, because it is because of this that we are in great danger. And the greatest danger is chemical pollution of the environment, since these pollution are not natural for nature, are not characteristic of it.

Types of chemical pollution

There are several types of chemical pollution:

Chemical pollution of the atmosphere;
Chemical contamination of the soil;
Chemical pollution of the oceans.

All of them are so global that it is necessary to stop in more detail and consider in more detail each type of these pollutions.

Atmospheric pollution: types and sources

The main sources of atmospheric pollution are transport, industry and household boilers. But the industry, of course, is bigger than the rest.

"Suppliers" of these pollution are metallurgical enterprises, thermal power plants, cement and chemical plants. They are the ones that release primary and secondary pollutants into the environment. The former immediately fall directly into the atmosphere, and the latter only during the course of any reactions (chemical, physical, photochemical, etc.).

And here are the most popular chemicals that are slowly but surely killing us: carbon monoxide and nitrogen, sulfuric and sulfurous anhydride, hydrogen sulfide and carbon disulfide, fluorine and chlorine compounds.

Aerosol compounds also have a huge negative impact on our atmosphere, the culprits of which are mass blasting, cement production, the burning of residual seafood, and the consumption of high-ash coal at thermal power plants.

Pollution of the oceans: types and sources

As a result of pollution of the waters of the World Ocean, the natural chemical composition of water changes, as the percentage of organic or inorganic harmful impurities in it increases.

From inorganic pollutants compounds can be distinguished: lead, arsenic, chromium, mercury, fluorine, copper, as well as inorganic acids and bases, which increase the pH range of industrial effluents.

The negative impact is manifested in the toxic effect. When released into the water, these toxins are absorbed by phytoplankton, which further along the food chain transfers toxins to more highly organized organisms.

From organic pollutants the main ones are petroleum products. Getting to the bottom, they partially or completely block the vital activity of microorganisms involved in the self-purification of waters. Further, when decaying, these sediments can create special toxic substances that pollute the waters. And one more negative consequence - these organic pollutants create a film on the surface and prevent light from penetrating deep into the waters, interfering with the processes of photosynthesis and gas exchange. The result of negative consequences can be, among other things, such terrible diseases as dysentery, typhoid fever, cholera.

Soil pollution: types and sources

The main "enemies" of the soil are acid-forming compounds, heavy metals, fertilizers, pesticides, oil and oil products.

Where do these types of pollution come from? Yes, from everywhere: from residential buildings, industrial and household enterprises, thermal power engineering, transport, agriculture.

The consequences of soil pollution are as sad as the pollution of the atmosphere and the World Ocean: pathogenic bacteria (tuberculosis, typhoid, gas gangrene, poliomyelitis, anthrax, etc.), substances toxic to living organisms, and lead enter the soil. All this not only pollutes the soil, but also disrupts the natural and normal circulation of substances, negatively affecting human health.

So we learned brief information about such a science as chemical ecology. It's scary to think how many bad things can happen to us if certain measures are not taken in time. And so that you have time to reflect on improving the quality of life and health of your loved ones and yourself, we offer our assistance in solving everyday student issues– writing essays, term papers, tests, etc.

Our planet is made up of chemical elements. These are mainly iron, oxygen, silicon, magnesium, sulfur, nickel, calcium and aluminum. Living organisms that exist on Earth also consist of chemical elements, organic and inorganic. Basically it is water, that is, oxygen and hydrogen. Still in the composition of living beings there is sulfur, nitrogen, phosphorus, carbon and so on. The excretions of living beings, as well as their remains, are composed of chemicals and compounds. All spheres of the planet - water, air, soil - are complexes of chemicals. All living and non-living nature interact with each other, resulting in, including pollution. But if everything consists of chemical elements, then they can also exchange and pollute each other with chemical elements. So, chemical pollution of the environment is the only type of pollution? Until recently, this was the case. There was only the chemistry of the environment and living organisms. But the achievements of science and their introduction into production have created other, apart from chemical forms and types of pollution. Now we are already talking about energy, radiation, noise, and so on. In addition, at present, environmental chemistry has begun to be supplemented with substances and compounds that were not previously found in nature and were created by man in the production process, that is, artificially. These substances are called xenobiotics. Nature is unable to process them. They do not enter the food chain and accumulate in the environment and organisms.

Chemical pollution still remains and is the main one.

Is pollution possible if the composition of the substance and its pollutant are the same? Perhaps because pollution occurs when the concentration of certain elements in a certain place or environment increases.

Thus, chemical pollution of the environment is an additional introduction into nature, including its flora and fauna, of chemical elements of natural and artificial origin. Sources of pollution are all processes occurring on Earth, both natural and man-made. The main characteristic of pollution can be considered the degree of their impact on living and inanimate nature. The consequences of pollution can be: eliminated and not, local and global, one-time and systematic, and so on.

The science

The ever-increasing anthropogenic influence on nature and the growing scale of its pollution gave impetus to the creation of a branch of chemistry called "Environmental Chemistry". Here the processes and transformations occurring in the soil, hydro- and atmosphere are studied, natural compounds and their origin are studied. That is, the scope of this section of scientific activity is the chemical processes in the biosphere, the migration of elements and compounds along natural chains.

In turn, environmental chemistry has its own subsections. One studies the processes occurring in the lithosphere, the other - in the atmosphere, the third - in the hydrosphere. In addition, there are departments that study pollutants of natural and anthropogenic origin, their sources, transformations, movement, and so on. At present, another department has been created - ecological, the scope of research of which is very close and sometimes identified with the general direction.

Environmental Chemistry is developing methods and means of protecting nature and is looking for ways to improve existing cleaning and disposal systems. This branch of chemistry is closely related to such areas of scientific research as ecology, geology, and so on.

It can be assumed that the largest source of environmental pollution is the chemical industry. But it is not so. Compared to other sectors of industrial production, or transport, enterprises in this industry emit significantly less pollutants. However, the composition of these substances contains much more various chemical elements and compounds. These are organic solvents, amines, aldehydes, chlorine, oxides and much more. It was at chemical enterprises that xenobiotics were synthesized. That is, this industry pollutes nature with its production and produces products that are an independent source of pollution. That is, for the environment, the sources of chemical pollution and production, and products, and the results of its use.

Chemical science and industry, key branches of human activity. They research, develop, and then produce and apply substances and compounds that serve as the basis for the structure of everything on Earth, including itself. The results of these activities have a real opportunity to influence the structure of living and non-living matter, the stability of the existence of the biosphere, the existence of life on the planet.

Types of pollution and their sources

Chemical pollution of the environment, as well as the corresponding branch of science, is conditionally divided into three types. Each species corresponds to a layer in the Earth's biosphere. These are chemical pollution: lithosphere, atmosphere and hydrosphere.

Atmosphere. The main sources of air pollution are: industry, transport and thermal stations, including household boilers. In industrial production, metallurgical plants, chemical enterprises and cement factories are leading in terms of emissions of pollutants into the atmosphere. Substances pollute the air both when they first enter it, and by derivative compounds formed in the atmosphere itself.

Hydrosphere. The main sources of pollution of the Earth's water basin are discharges from industrial enterprises, household services, accidents and ship discharges, runoff from agricultural lands, and so on. Pollutants are both organic and inorganic substances. The main ones include: compounds of arsenic, lead, mercury, inorganic acids and hydrocarbons in various forms and forms. Toxic heavy metals do not decompose and accumulate in organisms living in water. Oil and oil products pollute water both mechanically and chemically. Spilling a thin film on the surface of the water, they reduce the amount of light and oxygen in the water. As a result, the process of photosynthesis slows down, and decay accelerates.

Lithosphere. The main sources of soil pollution are the household sector, industrial enterprises, transport, heat power engineering and agriculture. As a result of their activities, heavy metals, pesticides, oil products, acidic compounds, and the like get into the ground. Changes in the chemical and physical composition of soils, as well as their structure, lead to the loss of their productivity, erosion, destruction and weathering.

Environmental chemistry has information about more than 5 million types of compounds, and their number is constantly growing, which in one way or another "travel" through the biosphere. More than 60,000 such compounds are involved in production activities.

Main pollutants and elements

Environmental chemistry considers the following elements and compounds as the main pollutants of nature.

Carbon monoxide is a colorless and odorless gas. An active compound that reacts with substances that make up the atmosphere. It underlies the formation of the "greenhouse effect". It is toxic and this property grows in the presence of nitrogen in the air.

Sulfur dioxide and sulfuric anhydride increase the acidity of the soil. Which leads to the loss of its fertility.

Hydrogen sulfide. Colorless gas. Distinguishable by the bright smell of rotten eggs. It is a reducing agent and oxidizes in air. It ignites at a temperature of 225 0 C. It is an accompanying gas in hydrocarbon deposits. It is present in volcanic gases, in mineral springs, and occurs at depths of more than 200 meters in the Black Sea. In nature, the source of its appearance is the decomposition of protein substances. In industrial production, it appears during the purification of oil and gas. used to obtain sulfur and sulfuric acid, various sulfur compounds, heavy water, in medicine. Hydrogen sulfide is toxic. It affects the mucous membranes and respiratory organs. If for most living organisms, it is a toxic substance, then for some microorganisms and bacteria it is a habitat.

nitrogen oxides. It is a poisonous gas that is colorless and odorless. Their danger grows in cities, where they mix with carbon and form photochemical smog. This gas adversely affects the human respiratory tract and can lead to pulmonary edema. It, together with sulfur oxide, is a source of acid rain.

Sulfur dioxide. A gas with a pungent, colorless odor. Affects the mucous membrane of the eyes and respiratory organs.

A negative impact on nature is caused by an increased content of fluorine, lead and chlorine compounds, hydrocarbons and their vapors, aldehydes and much more.

Substances designed and created to increase land fertility and crop productivity ultimately lead to soil degradation. The low degree of their assimilation at the places of application makes it possible for them to spread over considerable distances and “feed” plants that are not at all the ones for which they are intended. The main medium for their movement is water. Accordingly, a significant increase in green mass is also observed in it. Water bodies overgrow and disappear.

Almost all “chemical” pollutants of the natural environment have such a complex negative effect.

Until now, xenobiotics or artificially synthesized substances are classified as a separate category of pollutants. They do not enter the normal food chain cycle. There are no effective ways to process them artificially. Xenobiotics accumulate in soil, water, air, living organisms. They migrate from body to body. How will this accumulation end and what is its critical mass?

The result of human impact on the environment, namely, his activity gave rise to the seemingly impossible pollution of nature by what it consists of, is a change in its fundamental, deep composition and structure. The concentration of some chemical elements and the decrease in the volumes of others, generates unexplored and unpredictable, in terms of consequences, effects in the biosphere.

Video - How air pollution affects health

Introduction

Sources of chemical pollution

Energy facilities are the sources of the largest volumes of chemical pollution

Transport as a source of chemical pollution

Chemical industry as a source of pollution

Environmental impact of chemicals

Effects on Individuals and Populations

Impact on the ecosystem

Measures taken to minimize the risk of using chemical products

Technical measures used to prevent the danger of industrial emissions

6. Fight against losses during transportation (prevention of accidents of gas and oil pipelines).

Water pollution control

Recycling.

Conclusion

Bibliography

Introduction

The book "Ecological Problems" (p. 36) gives the following facts:

“About 5 thousand substances are now produced on a mass scale, and about 13 thousand substances on a scale of more than 500 tons / year. The number of substances offered on the market on a noticeable scale, from 50 thousand items in 1980, has increased to 100 thousand items at the present time. Of the 1338 substances produced on a large scale in the countries of the Organization for Economic Cooperation and Development (OECD), only 147 have some data on their danger or safety (Losev, 1989; TheWord…, 1992). According to (Meadows…, 1994), out of 65,000 chemicals in commercial circulation, less than 1% have toxicological characteristics.”

At present, for a number of reasons, the problems of assessing the toxicity of chemical products for humans, and to a greater extent in relation to the environment, remain unresolved. exhaustive research

Scope of information available	Industrial chemicals with production >500 t/y½<500 т/год½ Объем неизв			Food additives	Medicines fiziol. active in-va	Cosmetic ingredients		Pesticides, inert additives
Full, %	0	0	0	5	18		2	10
Incomplete, %	11	12	10	14	18		14	24
Not enough information, %	11	12	8	1	3		10	2
Very little information, %	0	0	0	34	36		18	26
No information, %	78	76	82	46	25		56	38
100	100	100	100	100		100	100
Number of chemical product studies	12860	13911	21752	8627	1815		3410	3350

impacts of substances can only be realized after complete information on the exposure (acting dose) of each chemical is obtained.

In the course of their economic activity, a person produces various substances. All produced substances using both renewable and non-renewable resources can be divided into four types:

* initial substances (raw materials);

* intermediate substances (arising or used in the production process);

* final product;

* by-product (waste).

table 2. Sources of emission (release) of harmful substances (%) in 1986 and forecast for 1998 (on the example of Germany).

SO2		NO x (NO 2)		co		Dust		Volatile organic compounds
Industry (sector of the national economy)	1996	1998	1996	1998	1996	1998	1996	1998	1996	1998
Total	100	100	100	100	100	100	100	100	100	100
Processes	4,3	7,9	0,8	0,4	11,9	15,0	57,7	59,1	4,6	7,0
Power consumption	95,7	92,1	99,2	99,6	88,1	85,0	42,3	40,9	56,4	60,4
transport, except urban a)	1,8	3,3	8,3	10,6	3,2	3,4	3,1	2,7	3,0	3,9
· urban transport	2,8	7,5	52,4	64,0	70,7	63,6	10,3	12,9	48,5	49,9
· household	5,8	9,6	3,1	3,5	9,0	10,5	6,7	6,1	3,0	3,7
small consumers b)	4,4	6,4	1,7	,1,8	1,5	2,0	1,6	1,3	0,5	0,7
processing plants and mines c)	12,6	14,7	7,1	7,0	2,9	4,3	4,1	4,6	0,8	1,1
Other processing industries c), d)	5,7	14,5	2,0	2,1	0,3	0,5	0,9	1,3	0,1	0,3
Electric and thermal power plants e)	62,6	36,1	24,6	10,6	0,5	0,7	15,6	12,0	0,5	0,8

a) Construction, agriculture and forestry, military, rail and water transport, air communications.

b) Including military services.

c) Industry: other areas of processing, enterprises and mining, processes (industrial only).

d) Oil refineries, coke batteries, briquetting.

e) For industrial power plants, only energy production.

From Table. 2 (p. 109) it can be seen that the largest amount of waste is associated with the production of energy, on the consumption of which all

Table 3 Air emissions from a 1000 MW/year power plant (in tons).

Pollution and waste from energy facilities are divided into two streams: one causes global changes, and the other - regional and local. Global pollutants enter the atmosphere, and due to their volume

Table 4. Changes in the concentration of certain gas components in the atmosphere.