Sources and types of water pollution. Environmental problems - water pollution

For a long time, the problem of water pollution was not acute for most countries. The available resources were sufficient to meet the needs of the local population. As industry grew and the amount of water used by humans increased, the situation changed dramatically. Now the issues of its purification and preservation of quality are dealt with at the international level.

Methods for determining the degree of pollution

Water pollution is usually understood as a change in its chemical or physical composition or biological characteristics. This determines restrictions on further use of the resource. Freshwater pollution deserves great attention, because its purity is inextricably linked to the quality of life and human health.

In order to determine the condition of water, a number of indicators are measured. Among them:

• color;
• degree of turbidity;
• smell;
• pH level;
• content of heavy metals, trace elements and organic substances;
• Escherichia coli titer;
• hydrobiological indicators;
• the amount of oxygen dissolved in water;
• oxidability;
• presence of pathogenic microflora;
• chemical oxygen consumption, etc.

In almost all countries there are supervisory authorities that must determine the quality of the contents at certain intervals, depending on the degree of importance of the pond, lake, river, etc. If deviations are detected, the reasons that could provoke water pollution are identified. Then measures are taken to eliminate them.

What causes resource pollution?

There are many reasons that can cause water pollution. This is not always associated with human or industrial activities. Natural disasters that occur periodically in different areas can also disrupt environmental conditions. The most common reasons are considered to be:

• Domestic and industrial wastewater. If they do not go through a purification system to remove synthetic, chemical elements and organic substances, then when they get into water bodies they can provoke a water-ecological disaster.
• . This problem is not talked about so often as not to provoke social tension. But exhaust gases that enter the atmosphere after emissions from motor vehicles and industrial enterprises, along with rain, end up on the ground, polluting the environment.
• Solid waste that can not only change the state of the biological environment in a reservoir, but also the flow itself. This often leads to floods of rivers and lakes and obstructed flow.
• Organic pollution associated with human activity, natural decomposition of dead animals, plants, etc.
• Industrial accidents and man-made disasters.
• Floods.
• Thermal pollution associated with the production of electricity and other energy. In some cases, the water heats up to 7 degrees, which causes the death of microorganisms, plants and fish, which require a different temperature regime.
• Avalanches, mudflows, etc.

In some cases, nature itself is capable of purifying water resources over time. But the period of chemical reactions will be long. Most often, the death of reservoir inhabitants and the pollution of fresh water cannot be prevented without human intervention.

The process of moving pollutants in water

If we are not talking about solid waste, then in all other cases pollutants may exist:

• in a dissolved state;
• in suspension.

They can be droplets or small particles. Biopollutants are observed in the form of living microorganisms or viruses.

If solid particles get into the water, they will not necessarily settle at the bottom. Depending on the current and storm phenomena, they are able to rise to the surface. An additional factor is the composition of the water. In the sea, it is almost impossible for such particles to sink to the bottom. As a result of the current, they easily move over long distances.

Experts point out that due to changes in current directions in coastal areas, the level of pollution is traditionally higher.

Regardless of the type of pollutant, it can enter the body of fish that live in a reservoir, or birds that look for food in the water. If this does not lead to the direct death of the creature, it can affect the further food chain. There is a high probability that this is how water pollution poisons people and worsens their health.

Main results of the impact of pollution on the environment

Regardless of whether the pollutant enters the body of a person, fish, or animal, a protective reaction is triggered. Some types of toxins can be neutralized by immune cells. In most cases, a living organism requires help in the form of treatment so that the processes do not become serious and lead to death.

Scientists determine the following indicators of poisoning, depending on the source of pollution and its influence:

• Genotoxicity. Heavy metals and other trace elements can damage and change the structure of DNA. As a result, serious problems are observed in the development of a living organism, the risk of diseases increases, etc.
• Carcinogenicity. Oncology problems are closely related to what kind of water people or animals drink. The danger lies in the fact that a cell, having turned into a cancerous one, can quickly degenerate the rest in the body.
• Neurotoxicity. Many metals and chemicals can affect the nervous system. Everyone knows the phenomenon of whale strandings, which are provoked by such pollution. The behavior of sea and river inhabitants becomes inadequate. They are not only capable of killing themselves, but also begin to devour those who were previously uninteresting to them. When chemicals enter the human body with water or food from such fish and animals, they can cause a slowdown in brain reactions, destruction of nerve cells, etc.
• Violation of energy exchange. By affecting mitochondria in cells, pollutants can alter energy production processes. As a result, the body stops performing active actions. Lack of energy can cause death.
• Reproductive failure. If water pollution causes the death of living organisms not so often, then it can affect health in 100 percent of cases. Scientists are especially concerned that their ability to reproduce a new generation is being lost. Solving this genetic problem can be difficult. Artificial renewal of the aquatic environment is required.

How does water control and purification work?

Realizing that freshwater pollution threatens human existence, government agencies at the national and international levels create requirements for the activities of enterprises and the behavior of people. These frameworks are reflected in documents regulating water control procedures and the operation of treatment systems.

The following cleaning methods are distinguished:

• Mechanical or primary. Its task is to prevent large objects from entering water bodies. To do this, special grilles and filters are installed on the pipes through which the waste flows to retain it. It is necessary to clean the pipes in a timely manner, otherwise the blockage may cause an accident.
• Specialized. Designed to capture pollutants of one type. For example, there are traps for grease, oil spills, and flocculent particles that are precipitated using coagulants.
• Chemical. Implies that wastewater will be reused in a closed cycle. Therefore, knowing their output composition, they select chemicals that can return the water to its original state. This is usually process water, not drinking water.
• Tertiary treatment. In order for water to be used in everyday life, agriculture, and the food industry, its quality must be impeccable. To do this, it is treated with special compounds or powders that can retain heavy metals, harmful microorganisms and other substances during multi-stage filtration.

In everyday life, more and more people are trying to install powerful filters that eliminate pollution caused by old communications and pipes.

Diseases that can be caused by dirty water

Until it became clear that infectious agents and bacteria can enter the body with water, humanity was faced with. After all, epidemics that were observed periodically in one country or another claimed the lives of hundreds of thousands of people.

The most common diseases that can result from bad water include:

• cholera;
• enterovirus;
• giardiasis;
• schistosomiasis;
• amoebiasis;
• congenital deformities;
• mental abnormalities;
• intestinal disorders;
• gastritis;
• skin lesions;
• burns of mucous membranes;
• oncological diseases;
• decreased reproductive function;
• endocrine disorders.

Purchasing bottled water and installing filters is a means of disease prevention. Some use silver objects, which also partially disinfect the water.

Water pollution can change the planet and make the quality of life completely different. That is why the issue of preserving reservoirs is constantly raised by environmental organizations and research centers. This allows you to attract the attention of enterprises, the public, and government agencies to existing problems and stimulate the beginning of active actions to prevent a disaster.

The pollutant poses a danger to living organisms such as plants or animals. Pollutants can be the result of human activity, such as an industrial byproduct, or occur naturally, such as radioactive isotopes, sediment, or animal waste.

Because of how broad the concept of pollution is, it can be assumed that polluted waters existed before the advent of negative human activities.

However, the amount of polluted water is increasing due to rapid population growth, agricultural activities and industrial development.

Main sources of water pollution

A number of human actions lead to water pollution, which is harmful to aquatic flora and fauna, aesthetic beauty, recreation and human health. The main sources of pollution can be grouped into several categories:

Land use

Humanity has a significant impact on the land, including cultivation of meadows, construction of buildings, laying roads, etc. Land use leads to disturbance during precipitation and snowmelt. As water flows over the plantless surface of the earth and forms streams, it picks up everything in its path, including harmful substances. Vegetation is important because it holds the organic and mineral components of the soil.

Impermeable surfaces

Most artificial surfaces cannot absorb water like soil and roots. Roofs, parking lots and roads allow rain or melted snow to flow at high speeds and volumes, picking up heavy metals, oils, road salt and other contaminants along the way. Otherwise, the pollutants would be absorbed by the soil and vegetation and break down naturally. Instead, they become concentrated in wastewater and then end up in waterways.

Agriculture

Common agricultural practices, such as soil exposure to fertilizers and pesticides, and livestock concentrations, contribute to water pollution. Water saturated with phosphorus and nitrates leads to algae blooms and other problems, including. Poor management of agricultural land and livestock can also lead to significant soil erosion.

Mining

Mine tailings are piles of discarded rocks after a valuable portion of the ore has been removed. Tailings can leach large amounts of contaminants into surface and groundwater. By-products are sometimes stored in artificial reservoirs, and the absence of dams to retain these reservoirs can lead to environmental disaster.

Industry

Industrial activities are the main source of water pollution. In the past, liquid waste was dumped directly into rivers or placed in special barrels, which were then buried somewhere. These barrels then began to break down, and harmful substances seeped into the soil and then into groundwater. In addition, accidental spills of pollutants occur quite often and have negative consequences for human health and safety.

Energy sector

The extraction and transportation of fossil fuels, especially oil, results in spills that can have long-lasting impacts on water resources. In addition, coal-fired power plants release large amounts of sulfur dioxide and nitrogen oxides into the atmosphere. When these pollutants dissolve in rainwater and enter waterways, they significantly acidify rivers and lakes. Producing electricity through hydropower results in significantly less pollution but still has some harmful effects on aquatic ecosystems.

Home activities

There are many actions we can take every day to prevent water pollution: avoid using pesticides, pick up pet waste, properly dispose of household chemicals and medications, avoid plastic, watch out for oil leaks in your car, clean out drains regularly, etc.

Garbage

A lot of garbage remains in the environment, and plastic products are not biodegradable, but only break down into harmful microparticles.

Are substances always pollutants?

Not always. For example, nuclear power plants use huge amounts of water to cool the reactor using a steam generator. The warm water then flows back into the river from which it was pumped, creating a warm plume that affects aquatic life downstream.

UDC 330

graduate student

Graduate School of Business of the Southern Federal University

Rostov-on-Don

SOURCES OF WATER POLLUTION as one of the main problemseconomyenvironmental management

SOURCES OF POLLUTION OF WATER RESOURCES AS ONE OF THE MAIN PROBLEMS OF ECONOMY OF ENVIRONMENTAL MANAGEMENT

Pollution of water resources is a decrease in their quality as a result of various physical, chemical or biological substances entering rivers, streams, lakes, seas and oceans. Pollution of water resources is a change in its chemical and physical state, as well as its biological properties, which leads to unsuitability for consumption. Water pollution occurs when contaminants are directly or indirectly released into water without adequate treatment and removal measures.

In most cases, freshwater pollution remains invisible because the pollutants are dissolved in the water. These waters are neither fresh nor salt. They can be divided into two types: the first come from city apartments, from the city sewerage system, the second - from industrial enterprises.

Population growth, the expansion of old cities and the emergence of new cities have significantly increased the flow of domestic wastewater into inland water bodies. These drains have become a source of pollution of rivers and lakes with pathogenic bacteria and helminths. To an even greater extent, synthetic detergents, widely used in everyday life, pollute water bodies. They are also widely used in industry and agriculture. Fertilizers washed off the soil surface end up in drains leading to lakes and seas. The chemicals they contain, entering rivers and lakes with wastewater, have a significant impact on the biological and physical regime of water bodies. As a result, the ability of water to saturate with oxygen is reduced, and the activity of bacteria that mineralize organic matter is paralyzed. All these reasons lead to severe water pollution, especially in closed basins, lakes, and bays.

Industrial wastewater is contaminated mainly by waste and emissions from production. Their quantitative and qualitative composition is diverse and depends on the industry and its technological processes; they are divided into two main groups: those containing inorganic impurities, including toxic ones, and those containing poisons.

Every year, thousands of chemicals enter water sources, the effect of which on the environment is not known in advance. Hundreds of these substances are new compounds. Although industrial wastewater is often pre-treated, it still contains toxic substances that are difficult to detect.

The first group includes wastewater from soda, sulfate, nitrogen fertilizer plants, processing factories of lead, zinc, nickel ores, etc., which contain acids, alkalis, heavy metal ions, etc. Wastewater from this group mainly changes the physical properties of water.

Heated wastewater from thermal power plants and other industries causes “thermal pollution,” which can have quite serious consequences: heated water has less oxygen, the thermal regime changes sharply, which negatively affects the flora and fauna of water bodies. As a result, an increase in water temperature in these reservoirs leads to the acceleration of certain biochemical processes in them, the finely balanced reproduction cycles of various organisms are disrupted, and favorable conditions arise for the massive development of blue-green algae in reservoirs - the so-called “water bloom”. Thermal pollution is introduced into surrounding water bodies by waste cooling water. Rivers are also polluted during rafting and during hydropower construction, and with the beginning of the navigation period, pollution by river fleet vessels increases.

Wastewater of the second group is discharged by oil refineries, petrochemical plants, organic synthesis enterprises, coke plants, etc. The wastewater contains various petroleum products, ammonia, aldehydes, resins, phenols and other harmful substances. The harmful effect of wastewater from this group lies mainly in oxidative processes, as a result of which the oxygen content in water decreases, the biochemical need for it increases, and the organoleptic characteristics of water deteriorate.

Oil and petroleum products at the present stage are the main pollutants of inland waters, waters and seas, and the World Ocean. When they enter water bodies, they create various forms of pollution: an oil film floating on the water, dissolved or emulsified in water. Petroleum products, heavy fractions that have settled to the bottom, etc. At the same time, the smell, taste, color, surface tension, viscosity of water changes, the amount of oxygen decreases, harmful organic substances appear, water acquires toxic properties and poses a threat not only to humans. 12 g of oil makes a ton of water unfit for consumption.

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

The life of the population of reservoirs is adversely affected by wastewater from the pulp and paper industry. Oxidation of wood pulp is accompanied by the absorption of a significant amount of oxygen, which leads to the death of eggs, fry and adult fish. Fibers and other insoluble substances clog the water and impair its physicochemical properties. Mole alloys have an unfavorable effect on fish and their food - invertebrates. Rotting wood and bark release various tannins into the water. Resin and other extractive products decompose and absorb a lot of oxygen, causing the death of fish, especially juveniles and eggs. In addition, moth floats heavily clog rivers, and driftwood often completely clogs their bottom, depriving fish of spawning grounds and feeding places.

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

Unfortunately, people cannot refuse chemical and pulp and paper mills, electroplating shops, metallurgical and engineering plants, nuclear power plants and everything else that saturates water with heavy metals, chemistry and radioactive isotopes.

The pollution of water bodies with pesticides and mineral fertilizers that fall from the fields along with streams of rain and melt water is of serious concern. As a result of research, for example, it has been proven that insecticides contained in water in the form of suspensions are dissolved in petroleum products that contaminate rivers and lakes. This interaction leads to a significant weakening of the oxidative functions of aquatic plants. Once in water bodies, pesticides accumulate in plankton, benthos, and fish, and enter the human body through the food chain, affecting both individual organs and the body as a whole.

Industrial and agricultural wastewater that enters water sources contains high levels of nitrates and phosphates. This leads to oversaturation of closed reservoirs with fertilizing substances and causes increased growth of simple algae microorganisms in them. Blue-green algae grows especially strongly. But, unfortunately, it is inedible for most fish species. The growth of algae leads to the absorption of more oxygen from the water, as a result of which plants and living things cannot survive in such an environment. However, microorganisms that are capable of decomposing dead plant and animal tissues multiply rapidly in it. These microorganisms absorb even more oxygen and form even more nitrates and phosphates. Gradually, the number of plant and animal species in such a reservoir decreases significantly. The most important victims of the ongoing process are fish. Eventually, the decrease in oxygen concentration due to the growth of algae and microorganisms that decompose dead tissue leads to the aging of lakes and their waterlogging. This process is called eutrophication.

Acid rain also makes a certain contribution to the increase in the concentration of heavy metals in water. They are able to dissolve minerals in the soil, which leads to an increase in the content of heavy metal ions in the water. Acid rain occurs as a result of exhaust gases released by metallurgical plants, thermal power plants, oil refineries, as well as other industrial enterprises and road transport entering the atmosphere. These gases contain oxides of sulfur and nitrogen, which combine with moisture and oxygen in the air to form sulfuric and nitric acids. These acids then fall to the ground - sometimes many hundreds of kilometers away from the source of the air pollution.

If there is a large amount of suspended solids in the water, they make it opaque to sunlight and thereby interfere with the process of photosynthesis in water bodies. This in turn causes disturbances in the food chain in such pools. In addition, solid waste causes siltation of rivers and shipping channels, necessitating frequent dredging.

It is often difficult to determine the source of water pollution - it could be an unauthorized release of harmful substances from an enterprise, or pollution caused by agricultural or industrial activities. This leads to contamination of water resources with nitrates, phosphates, toxic heavy metal ions and pesticides.

Water pollution is a serious problem for the Earth's ecology. And it should be solved both on a large scale - at the level of states and enterprises, and on a small scale - at the level of every human being.

Literature.

1. Ostroumov, self-purification and restoration of aquatic ecosystems. Pollution, self-purification and restoration of aquatic ecosystems. M.: MAKS Press Publishing House, 2005. – P.63-89

2. Savon and the importance of environmental audit in the Russian economy // Accounting and Statistics, 2005. – No. 7. – P. 106-110.

3. , Bugaets problems of the Tsimlyansk reservoir and the ecosystem of the lower Don // Education, science, production and management, 2011. - T. II. – P. 66-71.

4. , Gassiy providing an environmental monitoring system in the economics of environmental management of the Southern Federal District//Business. Education. Right. Bulletin of the Volgograd Institute of Business, 2012. – No. 1. – P. 98-104.

5. , Gassi investment policy for environmental protection // Bulletin of Moscow University. Series 6: Economics, 2012. – No. 2. – P. 45-53.

6. , Gassy of sustainable development of the Rostov region //Engineering Bulletin of the Don, 2012. – T. 22. – No. 4-1. – P. 159.

Annotation.

Currently, the problem of water pollution is the most pressing, because everyone knows the expression “water is life.” A person cannot live without water for more than three days, but even understanding the importance of the role of water in his life, he still continues harshly exploit water bodies, irreversibly changing their natural regime with discharges and waste.

Currently, the problem of water pollution is the most relevant, since Everyone knows the expression - "water - it"s life" Without water, people can not live more than three days, but even understanding the importance of the role of water in his life, he still continues to operate the hard water bodies, permanently altering their natural mode discharges and waste.

Keywords.

water pollution, harmful substances, sources of pollution, wastewater

water pollution, pollutants, sources of pollution, wastewater

Introduction: the essence and significance of water resources……………………….… 1

1. Water resources and their use…………………………………….. 2

2. Water resources of Russia ………………………………………………….... 4

3. Sources of pollution…………………………………………………... 10

3.1. General characteristics of pollution sources…………………...… 10

3.2. Oxygen starvation as a factor in water pollution……….… 12

3.3. Factors hindering the development of aquatic ecosystems…………… 14

3.4. Waste water……………………………………………………………...……… 14

3.5. Consequences of wastewater entering water bodies………………..…… 19

4. Measures to combat water pollution……………………... 21

4.1. Natural purification of water bodies……………………………..…… 21

4.2. Methods of wastewater treatment…………………………………….…… 22

4.2.1. Mechanical method…………………………………………….… 23

4.2.2. Chemical method…………………………………………………………….….23

4.2.3. Physico-chemical method………………………………………...… 23

4.2.4. Biological method………………………………………………………….... 24

4.3. Drainless production ………………………………………………………… 25

4.4. Monitoring of water bodies ………………………………………… 26

Conclusion………………………………………………………………………………….. 26

Introduction: the essence and significance of water resources

Water is the most valuable natural resource. It plays an exceptional role in metabolic processes that form the basis of life. Water is of great importance in industrial and agricultural production; its necessity for the everyday needs of humans, all plants and animals is well known. It serves as a habitat for many living creatures.

The growth of cities, the rapid development of industry, the intensification of agriculture, a significant expansion of irrigated land areas, improvement of cultural and living conditions and a number of other factors are increasingly complicating the problems of water supply.

The demand for water is enormous and increasing every year. The annual water consumption on the globe for all types of water supply is 3300-3500 km 3 . Moreover, 70% of all water consumption is used in agriculture.

The chemical and pulp and paper industries, ferrous and non-ferrous metallurgy consume a lot of water. Energy development is also leading to a sharp increase in water demand. A significant amount of water is spent for the needs of the livestock industry, as well as for the household needs of the population. Most of the water, after being used for domestic needs, is returned to rivers in the form of wastewater.

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

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

1. Water resources and their use

The water shell of the earth as a whole is called the hydrosphere and is a collection of oceans, seas, lakes, rivers, ice formations, groundwater and atmospheric waters. The total area of ​​the Earth's oceans is 2.5 times larger than the land area.

The total water reserves on Earth are 138.6 million km 3 . About 97.5% of water is salty or highly mineralized, that is, requiring purification for a number of uses. The World Ocean accounts for 96.5% of the planet's water mass.

For a clearer idea of ​​the scale of the hydrosphere, one should compare its mass with the mass of other shells of the Earth (in tons):

Hydrosphere - 1.50x10 18

Earth's crust - 2.80x10"

Living matter (biosphere) - 2.4 x10 12

Atmosphere - 5.15x10 13

An idea of ​​the world's water reserves is given by the information presented in Table 1.

Table 1.

Currently, the availability of water per person per day varies in different countries of the world. In a number of countries with developed economies, the threat of water shortages is imminent. The shortage of fresh water on earth is growing exponentially. However, there are promising sources of fresh water - icebergs born from the glaciers of Antarctica and Greenland.

As you know, a person cannot live without water. Water is one of the most important factors determining the location of productive forces, and very often a means of production. The increase in water consumption by industry is associated not only with its rapid development, but also with an increase in water consumption per unit of production. For example, to produce 1 ton of cotton fabric, factories spend 250 m 3 of water. The chemical industry requires a lot of water. Thus, the production of 1 ton of ammonia requires about 1000 m 3 of water.

Modern large thermal power plants consume huge amounts of water. Only one station with a capacity of 300 thousand kW consumes up to 120 m 3 /s, or more than 300 million m 3 per year. Gross water consumption for these stations will increase approximately 9-10 times in the future.

One of the most significant water consumers is agriculture. It is the largest water consumer in the water management system. Growing 1 ton of wheat requires 1500 m3 of water during the growing season, 1 ton of rice requires more than 7000 m3. The high productivity of irrigated lands has stimulated a sharp increase in the area worldwide - it is now equal to 200 million hectares. Constituting about 1/6 of the total crop area, irrigated lands provide approximately half of agricultural products.

A special place in the use of water resources is occupied by water consumption for the needs of the population. Household and drinking purposes in our country account for about 10% of water consumption. At the same time, uninterrupted water supply, as well as strict adherence to scientifically based sanitary and hygienic standards, are mandatory.

The use of water for economic purposes is one of the links in the water cycle in nature. But the anthropogenic link of the cycle differs from the natural one in that during the process of evaporation, part of the water used by humans returns to the atmosphere desalinated. The other part (which, for example, makes up 90% for water supply to cities and most industrial enterprises) is discharged into water bodies in the form of wastewater contaminated with industrial waste.

According to the State Water Cadastre of Russia, the total water intake from natural water bodies in 1995 amounted to 96.9 km 3 . More than 70 km 3 were used for the needs of the national economy, including for:

industrial water supply – 46 km 3 ;

In 1987, our planet's population exceeded 5 billion people, of which more than half consumed water almost 10 times less than the average amount spent per person in the world. At the same time, wastewater pollution is growing rapidly, bringing with it epidemics with dire consequences. According to the World Health Organization (WHO), 25 thousand people die every day from consuming contaminated water, and the number of annual victims from bad water is about 9 million people (in total, about 500 million people on Earth suffer annually from diseases associated with water pollution). Human). If the world's population reaches the current average level of water consumption, then pollution will double, and it can be assumed that the number of diseases and deaths from contaminated water will increase significantly.

At the dawn of human civilization, water pollution mainly contained waste products of humans and other living organisms. They did not pose a significant danger that could make any noticeable changes in the natural biochemical processes of nature. Natural waters easily coped with such pollution, which was facilitated by the oxygen and aquatic organisms contained in the water. However, the natural ability of self-purification, of course, has its limits, when violated, the remarkable ability to self-purify first weakens, loses activity, and then completely disappears.

After the start of the Industrial Revolution XVIII - early. XIX centuries, during the period of transition from manufacture to machine-factory production and the rapid growth of cities, discharges of polluted wastewater into natural reservoirs sharply increased. When water that is not purified from waste products enters the water supply system, it causes frequent outbreaks of epidemics.

The scale of disasters caused by pollution of water bodies can be illustrated by outbreaks of epidemics in India (1940-1950) caused by fecal infections, which led to massive infectious diseases with a lethal outcome from gastrointestinal diseases alone in 27,430,000 people.

Despite the fact that the need to purify water before supplying it to the drinking water supply has become obvious, this requirement cannot yet be met everywhere. Over the past decades, industrialized countries have begun to produce such a huge amount of various substances (water pollutants) that water treatment plants do not provide the necessary purification of drinking water. According to the US National Association for the Protection of Nature, about 26 million Americans drink water with pathogenic bacteria, 10 million with radioactive substances, 7 million with pesticides and lead. In many other countries, water pollution also exceeds not only the maximum permissible concentrations established by man himself, but also contradicts basic common sense, which calls for the preservation of all living things - for survival.

In recent decades, pollution of the hydrosphere and all its components - oceans, seas, rivers, ponds, swamps, groundwater - has especially progressed. The main source of pollution is anthropogenic waste: domestic and industrial wastewater, oil, radioactive substances. The amount of these and many other hydrosphere pollution continues to grow catastrophically. Dangerous pollution by oil and radioactive substances is already covering vast areas of the World Ocean.

Due to the sharply increased scale of human industrial activity, a huge amount of suspended and dissolved substances, mainly inorganic, organic, bacterial and biological, enter natural water bodies. A source of pollution is considered to be an object that introduces pollutants, microorganisms, and heat into surface or groundwater. In most cases, the cause of pollution of water basins is the discharge of untreated or partially treated wastewater into water bodies after their use in industrial and domestic human activities.

The variety of industrial and municipal wastewater makes their classification difficult. Based on the content of pollutants, water bodies are divided into three groups: those containing inorganic, organic, bacterial And biological substances.

The first group includes mineral impurities containing particles of sand, clay, mineral salts, acids, alkalis, sulfur compounds, and heavy metal ions. These include the waters of sulfuric acid, soda and nitrogen fertilizer plants, mines and mines, processing factories of lead, zinc, nickel ores and other industries, the waste water of which adversely affects natural water, significantly worsening its natural properties - taste, smell, color, transparency, pH.

The second group of pollution includes organic substances, which also include toxic ones. Such wastewater usually enters reservoirs from oil refineries and petrochemical plants, synthetic rubber and organic synthesis enterprises, coke, gas shale, ferromanganese and other enterprises. These effluents contain phenols, resins, hydrogen sulfide, ammonia, ketones, naphthenic acids and petroleum waste that are dangerous to vegetation and living organisms of water bodies.

The third group of pollution is household wastewater, discharges from medical and food industry enterprises; This should also include wastewater from some industrial enterprises - slaughterhouses, tanneries, biofactories, wool and fur processing plants, etc.

Based on the source of pollution, wastewater is divided into industrial, agricultural, domestic and atmospheric. Industrial wastewater is a consequence of the production of various sectors of the national economy, among which the largest consumers of water are ferrous and non-ferrous metallurgy, chemical, petrochemical, forest chemical and oil refining industries.

Agricultural pollution of water bodies is caused by the use of pesticides to suppress pests and diseases of plants and weeds. These chemicals wash over large areas and inevitably end up in water bodies. In addition, large amounts of pollution enter water bodies from livestock farming.

Domestic wastewater is associated with the life of cities and towns. These are mainly domestic wastewater containing feces and microorganisms, including pathogenic ones.

Atmospheric waters contain pollutants of industrial origin that enter the air and are then captured by condensing atmospheric moisture, as well as coming with evaporation from water runoff that washes away city streets and the territories of industrial enterprises.

It has already been said that the pollution of ponds, rivers, lakes, seas and oceans increases sharply every year, so it is necessary to dwell in more detail on the listed sources of pollution.

The main sources of natural water pollution include wastewater from industrial and municipal enterprises. Among the first are industrial waste from the development of ore and other minerals, wood waste from the processing and procurement of forest materials, primary processing of flax and other crops, discharges from water and rail transport. In addition, among industrial wastewaters, effluents from light industry enterprises, especially textile, leather, and fur industries, are especially important in polluting water bodies with surfactants (surfactants) and synthetic detergents (SDS). Here they are used as detergents for cleaning wool, cotton yarn, for dyeing, bleaching and printing fabrics, or, for example, for degreasing raw leather when tanning it. In other industries, surfactants are needed in various “wet” technologies, such as flotation concentration of ores, separation of chemical products.

Another major polluter of water sources using surfactants is the oil industry, which widely uses these synthetic substances in its technological processes. Thus, surfactants are needed to improve the technology of drilling oil and gas wells, to combat paraffin deposits and equipment corrosion.

Discharge of SMS into natural bodies of water, even in small quantities, leads to the formation of foam and also gives the water an unpleasant specific odor. Synthetic detergents have a depressing effect on biochemical processes, and their concentration in water of about 1 mg/l leads to the death of small plankton, when increased to 3 mg/l - the death of daphnia, and up to 5 mg/l - the death of fish.

Industrial and gas production enterprises heavily pollute wastewater with minerals, inorganic substances, salts and acids. Emissions often contain metal salts, metals themselves and their oxides, various acids and cyanide compounds, which, when affecting the human body, can cause intoxication, and at a certain toxic dose lead to severe poisoning with a complex of characteristic pathological changes in the body. Aquatic organisms accumulate toxic substances that are slowly eliminated and are almost never neutralized (DDT, mercury, lead). Many of these substances have the ability to persist in water for many years and pose a risk of poisoning to people.

International statistics indicate that the “toxic situation” that has developed in economically developed countries is characterized by a constant increase in the number of general poisonings, among which household and accidental poisonings are in first place in frequency, so-called suicidal or intentional poisonings are in second place, and occupational poisoning related to work-related diseases and injuries.

A special place among objects that pollute the hydrosphere is occupied by the chemical industry with all related industries in industrialized countries. The rapid development of the chemical industry reflects visible, global problems of its development. Among the countries of the world with a powerful chemical industry, the USA, Russia, Great Britain, Germany, France, and Japan are in the first row. The USA produces about 30% of all world chemical products, the average annual growth rate in the 60s. was 7% , in the early 70s the growth of chemical products decreased and only in the 80s. recovered. One of the largest chemical powers - Japan - in the 60s. had an annual increase in chemical production of 13-19%, and now this island state produces 8-10% of world chemical production.

The share of developing countries in world chemistry in the early 80s. rose to 9%. In the foreseeable future, we can expect that more and more countries will participate in global chemical production. The well-known motto “live better thanks to chemistry” has turned heads and is supported worldwide not only in industrialized countries. Meanwhile, the theory and practice of environmental protection, including the protection of hydrosphere water resources from uncontrolled pollution in the third millennium, largely lags behind the rapid rise of chemical production.

Complex problems of protecting natural water bodies from pollution are associated with industrial wastewater from petrochemical and chemical enterprises. Phenols, which are especially dangerous for water bodies, are increasingly appearing in wastewater from enterprises in these industries. Once in a body of water, phenol covers the surface of the water with a fluorescent film, disrupting natural biological processes and the balance of ecosystems. If there is phenol in the water, the process of biological purification of the reservoir slows down sharply; when its content exceeds 0.001 mg/l, the water acquires an unpleasant taste and the specific smell of carbolic acid; at 0.01-0.1 mg/l, fish meat acquires an unpleasant taste and smell, and when In high concentrations, the fish is completely inedible. A particularly large amount of phenol is contained in wastewater from coke plants, which discharge up to 4-10 tons of phenol into water bodies during the day.

Among the industrial products that pollute water bodies with toxic substances that are dangerous to many aquatic organisms, hydrocarbons are widespread - oil, fuel oil, gasoline, kerosene, etc. When they enter a water body with wastewater, they give the water an unpleasant odor, change color, cover the surface of the water with a film, and mixing with synthetic detergents - thick foam. This sharply disrupts the natural process of gas exchange with the atmosphere and, ultimately, leads to a significant decrease in the oxygen content in the water and, as a result, the death of life in the reservoir.

Motor gasoline and diesel oil, even in low concentrations - 0.01 mg/l - make water unfit for drinking; more precisely, 1 mg of these substances when entering a reservoir makes 10 liters of water unfit.

Petroleum products entering a reservoir create a film floating on the surface of the water, as well as a mixture of resin particles in emulsified and dissolved forms. It has been established that just one drop of oil spreads on the surface into a film with an area of ​​about 25 m2, and one ton of oil covers more than 500 hectares of the surface of a reservoir, which prevents gas exchange, including the absorption of oxygen by water. The lack of aeration, which creates an oxygen deficiency, inhibits many aquatic organisms and can be detrimental to the life of water bodies.

Dissolved and emulsified petroleum products cause great harm to many aquatic bacteria. When the concentration of sulfur oil and its products in water is more than 0.2 mg/l, the death of juvenile fish is observed, at 1.4 mg/l - benthos and 16 mg/l - fish kill. The processes of self-purification of water from phenol and petroleum products proceed very slowly, and these contaminants (their traces) are detected at a distance of up to 100 km from the discharge site.

Domestic wastewater, which carries with it human physiological waste, water from kitchens, canteens, mechanized laundries, hospitals, baths, household water generated when washing premises, garages, etc., as mentioned above, also pollutes water bodies. In these waters, organic matter makes up about 60%, the rest, about 40%, is mineral. Organic substances in the process of decomposition in natural reservoirs require a lot of oxygen, and a deficiency of the latter leads to the death of many aquatic organisms and disruption of ecosystems.

A feature of municipal wastewater is its bacterial contamination, in which 1 mm 3 of water can contain tens of millions of pathogenic bacteria. Natural water polluted by such discharges is completely unsuitable for water supply to the population. It contains bacteria and viruses, causative agents of dangerous diseases that contribute to outbreaks of various infectious diseases, such as cholera, dysentery, mumps, infectious viral hepatitis, tularemia, etc.

With household wastewater, synthetic detergents can also enter natural water bodies. Thus, the effluents of large mechanized laundries contain surfactants from 200 mg/l and above. Consumption of surfactants per inhabitant is 3.5 g per day. With water consumption in the range of 150-350 liters per person per day, the average calculated concentration of surfactants in municipal wastewater is 7.1-20 mg/l. But in addition to surfactants, wastewater contains various ingredients of synthetic detergents, among which sodium tripodiphosphate, soda ash, sodium silicate, optical brighteners, alkylamides, sodium sulfate, perfumes and other substances predominate. Storm drains are also of a certain importance; during prolonged rains, their volume can exceed domestic waste, and contamination of the surface of industrial sites, debris and chemical waste will significantly increase the pollution of water bodies.

Thermal pollution is associated mainly with the drainage of water and coolants in industrial processes, as well as systems of energy producers and energy consumers into natural reservoirs. The influx of thermal waters, for example, from nuclear power plants and metallurgical plants, results in a temperature difference in reservoirs of up to 30°C, which reduces the oxygen content in water, complicates normal gas exchange, stimulates outbreaks of algae blooms, increases the toxicity of toxic substances, disturbing biological balance.

Agriculture is increasingly becoming a dangerous source of water pollution, and this danger is growing every year. Water from agricultural fields may contain synthetic detergents, various chemical compounds to combat harmful insects, weeds, and fungi. It is characteristic that over two decades the production and use of mineral fertilizers and plant protection products in our country has increased more than 18 times. This increase in the number of pesticides designed to kill insects and weeds and promote increased crop yields is understandable. Indeed, the use of pesticides (insecticides, herbicides, fungicides), chemicals that have toxic properties in relation to certain living organisms, in recent decades has made it possible not only to increase agricultural production, but also to prevent diseases dangerous to humans such as malaria and typhus However, when they get into natural bodies of water (if they are used incorrectly) in significant doses, pesticides, especially organochloride ones (DDT and more toxic ones - dieldrin and endrin), do not undergo biological decomposition for many months, accumulate in living organisms of plankton and fish, passing through food chain into the human body.

The chemical industry produces many new substances with unknown or only partially known biological and toxicological properties. Among such substances, widespread use in the 50-60s. received the pesticide DDT, which was then successfully used in the fight against malaria and to increase crop yields. However, already in the early 60s. Scientists and practitioners have begun to raise concerns about the consequences of using biosustainable pesticides, and some have spoken out against the overuse of DDT. Thus, R. Carson, a scientist in the field of marine biology, wrote in the book “Silent Spring” that industrialists and owners of large industrial associations are only interested in making a quick profit and do not take into account the environmental consequences of using pesticides. In subsequent years, research by specialists here and abroad confirmed the legitimacy of condemning this kind of excess in the use of dangerous pesticides.

It has now been definitively established that DDT (as well as mercury) is a particularly dangerous toxic chemical that has the property of accumulation, i.e. accumulation in the tissues of animals and humans. Indeed, organochlorine compounds of DDT remain effective for 10-25 years. It is no coincidence that this dangerous substance was found in the carcasses of northern animals and waterfowl. It is also known that DDT, when it enters the body of animals and humans through the food chain, causes genetic changes and cancer. Therefore, here and in many countries abroad, DDT is not currently used.

In recent years, an extremely dangerous water pollutant – dioxide – has emerged. In the smallest doses, this special toxic chemical, when entering the human body, causes severe diseases that affect the hematopoietic, immune and nervous systems. Even in negligible doses, the poison has a carcinogenic and mutagenic effect.

When dioxide enters the body of a pregnant woman, it has a detrimental effect on the new body, destroying it. Diseases and deformities of people caused by poison are inherited. The liver poisoned by dioxide, as a result of mutations under the influence of the poison, begins to produce substances that are toxic to the body.

Wide circles of the public learned about the insidious toxic substance dioxide during the Vietnam War, when the Americans sprayed about 200 kg of this substance from airplanes. The result is a decades-long tragedy for Vietnamese and former American soldiers.

In agriculture, there is a major source of pollution - livestock farming, which creates a large amount of organic pollutants (manure, litter, urea), which ultimately end up in natural water bodies. Wastewater containing organic matter contains a lot of nutrients, including nitrogen and phosphorus. This stimulates the proliferation of phytoplankton (brown and blue-green algae), as well as higher aquatic plants. The rapid growth in the number of oxygen consumers leads over time to a deficiency of the latter. Anaerobic processes begin to develop in water, leading to autotrophication, i.e. increasing the biological productivity of water bodies as a result of the concentration of a large number of nutrients in water.

The most dangerous pollutants of the World Ocean, as well as for humans and all living things on the planet, have been since the second half of the twentieth century. become radioactive. In 1954, in the Pacific Ocean, after the explosion of a hydrogen bomb produced by the United States, a huge water area of ​​25,600 km 2 received deadly radiation. Ocean currents contributed to an increase in the area of ​​infection over several months to 2.5 million km 2.

Plants and biological objects accumulate radioactive substances, which are then transmitted to other organisms along the food chain. Cumulation, i.e. the accumulation of radioactive substances occurs so actively that the radioactivity of some planktonic organisms can be 1000 times higher than the radioactivity of water, and for some species of fish - up to 50 thousand times. These infections may expand their boundaries in unexpected ways. Animals infected with radioactive substances carry contamination over vast distances from the source of radiation (for example, birds that fly far, fish that swim long distances, etc.).

The degree and form of radioactive damage to biological organisms living in water depends mainly on the amount of absorbed radiation energy. The characteristics of absorbed doses and the degree of hazard depending on these doses are widely presented in the existing literature.

The Moscow Treaty Banning Tests of Nuclear Weapons in the Atmosphere, Space and Underwater (1963) put an end to massive radioactive contamination of the ocean and seas. Meanwhile, the burial of radioactive waste in the depths of the oceans continues, as a result of which the pollution problem has become even more acute. Containers with radioactive waste, destroyed by the aggressive ocean environment, become sources of contamination. Thus, in the Irish Sea, plankton, algae, fish and all living things in the water were contaminated with radioactive substances precisely because of the destruction of buried containers.

Radioactive contamination associated with the accident at the Chernobyl nuclear power plant led to significant and sad consequences and will be discussed below in the section “Hydrosphere contamination through the atmosphere.”

The problem of anthropogenic pollution of the World Ocean, as has become obvious, for its global solution requires centralized management of the activities of states in the use of sea and ocean waters. The XIX International Conference “Peace on the Seas”, held in Lisbon in 1991, was devoted to this problem. These conferences began in 1970, when, as if in unison with the encyclical of Pope John XXIII “Peace on Earth”, published in 1962 , the Peace on the Seas movement began, led by Professor Elisabeth Mann-Borgese, daughter of the writer Thomas Mann (headquarters in Malta). In particular, the conference drew attention to the need to build a new universal structure within the UN to protect the World Ocean, its resources, peaceful resolution of interstate disputes, etc. Such a structure could become a model for global, regional and national governance of human activities in the seas in the current and coming millennium.

The smallest particles of mercury, transforming it in their organisms into methyl mercury, which then goes along the food chain - “bacteria - plankton - mollusks - predators of water bodies, etc.” ultimately ends up in the human diet.