› › Sources and possible ways of pollution of surface and ground waters. Sources of water pollution in the modern world: how to determine the main types

Sources and possible ways of pollution of surface and ground waters. Sources of water pollution in the modern world: how to determine the main types

Main input and output flows of the city

Table #1

Nitric oxide is formed when forest fires. High concentrations of nitric oxide in the city are associated with human activities. A significant amount of nitrogen oxide is emitted at thermal power plants and internal combustion engines.

Carbon monoxide - its largest source - vehicles. Another source is tobacco smoke. Carbon monoxide binds to hemoglobin in the blood and, at high concentrations, can cause death.

Particles - dust - the causes of emissions into the atmosphere are dust storms,
soil erosion, volcanoes. About 20% of the dust in the atmosphere is the work of man:
production of building materials, cement, etc. American environmentalist Barton
said about the problem of air pollution with dust: “One of two things: either people
make it so that there is less smoke in the air, or the smoke will make it so that on
The earth will become less people.

Sources of pollution of the hydrosphere are biological, chemical and physical sources. Anthropogenic impact on the hydrosphere leads to a decrease in water reserves, a change in the state of the fauna and flora of water bodies, a violation of the cycle of many substances in the biosphere, a decrease in the biomass of the planet and, as a result, a decrease in the reproduction of oxygen.

The role of water in all life processes is generally recognized. Without water, a person can live no more than 8 days, for a year he consumes about 1 ton of water. A huge amount of fresh water is also required for both industrial and agricultural production. Now the amount of fresh water on the planet is only 2.5% of all water; 85% - sea water.

Above was the amount of wastewater emitted by the city per day. Depending on the conditions of formation, wastewater is divided into three groups:

· household sewage - drains from showers, laundries, baths, canteens, toilets, from washing floors, etc.;

Atmospheric waste water, or storm water. Stormwater runoff from industrial plants is especially dangerous. Due to their unevenness, the collection and treatment of these effluents is difficult.

Industrial waste water - liquid waste that
occur during the extraction and processing of raw materials.

Water pollutants are divided into biological that cause water fermentation; chemical that change the chemical composition of water; physical changing its transparency, temperature and other indicators.



Biological get along with domestic and industrial effluents (food, pulp and paper industry).

Chemical- petroleum products, heavy metals, mineral fertilizers, pesticides, detergents.

Physical- during discharges from the workings of mines, quarries, transport highways.

Used for wastewater treatment mechanical, chemical, physicochemical and biological methods. When they are used together, the method of purification and disposal of wastewater is combined. mechanical method allows you to remove up to 60-75% of insoluble impurities from domestic wastewater, and up to 95% from industrial wastewater; chemical method- up to 95% insoluble impurities and up to 25% - soluble. Physico-chemical method allows you to remove finely dispersed and dissolved inorganic impurities and destroy organic and poorly oxidized substances. There are several types biological devices for wastewater treatment: biofilters, biological ponds.

The main criterion for the quality of water and atmosphere in our country is MPC. In Russia, about 21 km of sewage are formed annually, of which 16 km are discharged into the Volga. Now a special resolution has been adopted to protect the environment in the Volga and Ural basins. To save water on the planet, it is necessary to learn how to use it repeatedly - to create closed water circulation systems, as well as to develop modern methods of water purification.

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  • 1. Introduction
  • 2. Types of pollution
  • conclusions
  • Bibliography
  • Applications

1. Introduction

Throughout their history, people have used surface waters (rivers, lakes) for their economic needs. This did not bring significant harm, since nature itself provided self-purification of reservoirs. In the XX century. the situation has changed dramatically. Urbanization, industrial growth and agricultural development have caused the pollution of rivers and lakes all over the world.

Water pollution is an artificial change in the chemical and physical state, as well as the biological characteristics of water, as a result of which its further use is limited. Water pollution - in the legislation of the Russian Federation is regarded as an environmental crime, the objective basis of which is pollution, clogging, depletion of surface water, groundwater, sources of drinking water supply, as well as other changes in their properties, during which significant harm was caused to the animal or plant world, fish stocks, forestry or agriculture. Depending on the severity of the consequences, water pollution can be considered an administrative or criminal offense.

The water quality of most water bodies does not meet regulatory requirements. Long-term observations of the dynamics of surface water quality reveal a trend towards an increase in the number of sites with a high level of pollution (more than 10 MPC) and the number of cases of extremely high content (over 100 MPC) of pollutants in water bodies. The state of water sources and centralized water supply systems cannot guarantee the required quality drinking water. This condition has reached dangerous levels for human health. Sanitary and epidemiological surveillance services constantly note high pollution of surface waters.

2. Types of pollution

About 1/3 of the total mass of pollutants is introduced into water sources with surface and storm runoff from territories of unsanitary areas, agricultural facilities and lands, which affects the seasonal, during the spring flood, deterioration in the quality of drinking water, annually noted in large cities. The main pollutants of surface waters:

oil and oil products;

· wastewater;

ions of heavy metals;

· acid rains;

· radioactive contamination;

thermal pollution;

· mechanical pollution;

bacterial and biological contamination.

The main sources of adverse effects on surface water bodies and their pollution are sewage - liquid waste from human household and industrial activities. Waste water is called water, which was formed after the use of drinking water by a person to meet certain needs in everyday life or at work. At the same time, additional impurities (pollution) got into the water, which changed and worsened its composition. Depending on the origin, wastewater is divided into:

1) household, or household and fecal, formed as a result of household activities of people mainly in residential and public buildings;

2) industrial, formed at industrial enterprises, as a result of technological production processes);

pollution surface water source

3) storm (atmospheric), formed as a result of the formation of surface runoff from asphalt and other coatings and soil during precipitation and snow melting. They flow into water bodies from the territories of populated areas, industrial sites and agricultural fields;

4) urban, which means a mixture of domestic and industrial wastewater generated in a settlement as a result of the discharge of untreated or pretreated industrial wastewater into the city sewer;

5) drainage water from irrigated lands;

6) waste water from livestock complexes;

7) wastewater from storage ponds that are discharged into water bodies during the spring flood. There are cases of forced discharge of sewage from reservoirs, with insufficient flow of the river, into regulated reservoirs, during floods, etc.;

8) sewage (fan) of passenger ships of the sea and river (including small size) fleet, cargo and oil terminals and ships.

In addition, water bodies are polluted when sand is taken and other works are carried out in their channel. Soaking fibrous plants in them, such as flax or hemp, leads to pollution of water bodies. Pollutes water bodies and timber rafting. Surface water bodies can be polluted through atmospheric air. Water bodies can also become polluted due to the mass extinction of aquatic organisms, animals and plants in them, especially in autumn time, resuspension of bottom sediments.

When entering water bodies, untreated or insufficiently treated wastewater pollutes them with suspended particles, organic substances, pathogenic and opportunistic bacteria, viruses, protozoan cysts, and helminth eggs. With industrial wastewater, a significant amount of toxic chemical substances.

Polluted water bodies lose their importance as a positive factor in maintaining the health of the population. The use of polluted water bodies can lead to water epidemics, mass poisoning of the population with toxic, carcinogenic, radioactive, allergenic, mutagenic substances. Reservoirs cause great harm to fish and fur farming, lose their health-improving value.

Oil and oil products at the present stage are the main pollutants of inland waters, waters and seas, the World Ocean. Getting into water bodies, they create different forms of pollution: oil film floating on water, dissolved or emulsified in water. Oil products, heavy fractions settled to the bottom, etc. At the same time, the smell, taste, color, surface tension, viscosity of water change, 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. Nuclear power plants pollute rivers with radioactive waste. Radioactive substances are concentrated by the smallest planktonic microorganisms and fish, then they are transferred along 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. The main source of radioactive pollution of the sea is low-level waste removed from nuclear power plants. One of the most important problems arising from this contamination is that marine organisms such as algae accumulate, or concentrate, radioactive isotopes. Thermal water pollution is caused by thermal or nuclear power plants. Thermal pollution is introduced into the surrounding water bodies by waste cooling water. As a result, an increase in water temperature in these reservoirs leads to the acceleration of some biochemical processes in them, as well as to a decrease in the oxygen content dissolved in water. This causes rapid and often very significant changes in the biological environment in the vicinity of power plants. There is a violation of the finely balanced cycles of reproduction of various organisms. In conditions of thermal pollution, as a rule, there is a strong growth of algae, but the extinction of other organisms living in the water.

3. Wastewater treatment methods

In rivers and other bodies of water, a natural process of self-purification of water occurs. However, it runs slowly. While industrial and household discharges were small, the rivers themselves coped with them. In our industrial age, due to sharp increase waste water bodies can no longer cope with such significant pollution. There was a need to neutralize, purify wastewater and dispose of them.

cleaning sewage waters- treatment of wastewater to destroy or remove harmful substances from them. The release of wastewater from pollution is a complex production. It, like in any other production, has raw materials (waste water) and finished products (purified water)

Wastewater treatment methods can be divided into:

mechanical,

chemical,

physicochemical and

biological,

when they are used together, the method of purification and disposal of wastewater is called combined. The use of a particular method in each specific case is determined by the nature of the pollution and the degree of harmfulness of impurities.

The essence of the mechanical method is that mechanical impurities are removed from wastewater by settling and filtration. Mechanical treatment allows you to isolate up to 60-75% of insoluble impurities from domestic wastewater, and up to 95% from industrial wastewater, many of which are used as valuable impurities in production. The chemical method consists in the fact that various chemical reagents are added to the wastewater, which react with pollutants and precipitate them in the form of insoluble precipitates. Chemical cleaning achieves a reduction of insoluble impurities up to 95% and soluble impurities up to 25%.

With the physico-chemical method of treatment, finely dispersed and dissolved inorganic impurities are removed from wastewater and organic and poorly oxidized substances are destroyed. Electrolysis is also widely used. It consists in the destruction of organic substances in wastewater and the extraction of metals, acids and other inorganic substances. Electrolytic purification is carried out in special facilities - electrolyzers. Wastewater treatment using electrolysis is effective in lead and copper plants, paint and varnish and some other industries.

Contaminated wastewater is also treated using ultrasound, ozone, ion exchange resins and high pressure, and chlorination has proven itself well. Among the wastewater treatment methods, a biological method based on the use of the laws of biochemical and physiological self-purification of rivers and other water bodies should play an important role. There are several types of biological wastewater treatment devices: biofilters, biological ponds and aeration tanks. In biological ponds, all organisms inhabiting the reservoir take part in wastewater treatment.

Aerotanks are huge reinforced concrete tanks. Here, the purifying principle is activated sludge from bacteria and microscopic animals. All these living creatures are rapidly developing in aerotanks, which is facilitated by the organic matter of sewage and the excess of oxygen entering the structure by the flow of supplied air. Bacteria stick together into flakes and secrete enzymes that mineralize organic pollution. Silt with flakes quickly settles, separating from the purified water. Infusoria, flagellates, amoebae, rotifers and other smallest animals, devouring bacteria that do not coalesce into flakes, rejuvenate the bacterial mass of sludge.

Wastewater is subjected to mechanical treatment before biological treatment, and after it, to remove pathogenic bacteria and chemical treatment, chlorination with liquid chlorine or bleach. For disinfection, other physical and chemical methods are also used (ultrasound, electrolysis, ozonation, etc.)

The biological method gives great results in the treatment of municipal wastewater. It is also used in the treatment of waste from oil refineries, the pulp and paper industry, and the production of artificial fibers.

4. History of surface water pollution in Russia

Pollution of surface waters began in central Russia as early as the 16th century, when fields were fertilized with manure. Since then, agriculture has been the main water pollutant in the central regions of the country. In the more northern regions, timber rafting, especially mole rafting, played a large role in pollution, in which the logs sank and rotted in the water. With the development of industry and the growth of cities, the role of municipal and industrial pollution began to grow. A sharp increase in pollution occurred in the twentieth century. A particular danger is associated with the coincidence of the period of growth in discharges of polluted wastewater and the centuries-old trend of increasing dryness of the climate, and a decrease in the water content of water bodies. Under these conditions, the concentrations of pollutants in solutions increase and, consequently, the degree of their harmful effects on natural systems and human health. By the beginning of the 1990s, the main pollutants of surface waters were oil products, phenols, easily oxidized organic substances, copper and zinc compounds, ammonium and nitrate nitrogen. (Annex 1)

In most industrialized regions of the country, wastewater discharges amounted to more than 100 cubic meters. m per capita. in the Irkutsk region and Krasnodar Territory it exceeded 500 cu. m per person. In the main industrial centers - Moscow, the Nizhny Novgorod region, etc. - more than 200, in St. Petersburg - more than 300. But for several decades, as a result of industrial and municipal discharges of polluted water, it is impossible to drink water from the Middle and Lower Volga. Despite the relatively high degree of provision of the basin with industrial and municipal treatment facilities for Russia, they do not work efficiently. Thus, the following was discharged into the reservoirs of the basin: oil products - 6.8 thousand tons, suspended solids - 257 thousand tons, sulfates - 1344 thousand tons, organic pollutants 176 thousand tons, total nitrogen - 12 thousand tons, nitrates - 69.7 thousand tons, iron - 35 thousand tons, zinc - 0.6 thousand tons, aluminum - 5.5 thousand tons, magnesium - 10.7 thousand tons, and mercury - 61 kg. . It is with this water that gardens and melons are watered in the Volga-Akhtuba floodplain, with products from which a significant part of the population of Russia is supplied. Fish from the Volga and Caspian deltas also live in this polluted water. The abundance of pathologies caused by water pollution in Caspian sturgeons is widely known. The bottoms of the Volga reservoirs are covered with silts containing, for example, huge concentrations of heavy metals, which, if they are washed out (for example, at especially low water levels or serious accidents of hydroelectric dams), can drastically worsen the ecological state of the entire basin. In general, the Volga-Caspian basin, in which 80 million people live, is perhaps the most dangerous in Russia in terms of the state of the water. The huge basin of the Ob River is extremely polluted by oil production. Salekhard, standing at the confluence of the huge Ob with its large tributary Poluy, is experiencing great difficulties with clean drinking water, it is transported around the city in cisterns. There are also much more exotic types of pollution. In almost all gold-mining provinces, the waters are heavily polluted with mercury, which is used for amalgamation in the gold-mining industry. But in some places they went further - for example, in the Aldan region, cyanides were used for this purpose. Banners were placed along the rivers forbidding drinking water, but cows and elks and, much worse, children cannot read. Although Russia owns the world's largest, completely unique reservoir of the purest fresh water - Lake. Baikal, the situation on it inspires concern, especially in connection with the activities of the Baikal Pulp and Paper Mill and the Selenginsky CCC, with wastewater from which up to 60% of hardly decomposable organic substances enter Baikal.

5. Impact of polluted surface water bodies on human health

Pollution of surface water bodies has a direct and indirect effect on human health. A direct harmful effect can manifest itself both when water enters the human body orally (a person deliberately drinks water from a polluted reservoir or accidentally swallowed it while swimming), and when it comes into contact with the skin and mucous membranes while swimming, bathing, etc. But more often In total, the harmful effect is carried out according to the scheme: polluted water of a surface reservoir - drinking water - a person. This is explained by the fact that technologies for the preparation of drinking water from surface water sources make it possible to improve only some of its properties. In particular, to reduce turbidity and color due to clarification and discoloration, to get rid of the epidemic danger by disinfection, to improve some indicators of the mineral composition by special methods of water treatment (desalination, softening, fluorination, defluorination, etc.). These technologies are sometimes not designed to remove certain harmful chemicals from the water. If their concentration in a water body at water intake points significantly exceeds the MPC, they can practically pass through water treatment facilities in transit, get into drinking water, and with drinking water - into the human body. Consequently, on the one hand, the consumption or use by the population of water from reservoirs contaminated with enteropathogenic bacteria and viruses, protozoa, helminths can lead to massive infectious diseases and invasions, and on the other hand, the use by humans of polluted water that contains harmful chemical substances in concentrations exceeding the MPC can cause acute or chronic poisoning with possible long-term consequences (allergenic, teratogenic, mutagenic, carcinogenic).

Indirect, or indirect, harmful effect of water bodies on human health occurs according to the scheme: polluted water - contaminated food ("seafood") - a person; polluted reservoir - irrigation of agricultural land - foodstuffs of vegetable origin - human; polluted reservoir - cattle watering place - milk - human, etc. That is, the indirect harmful effect of polluted reservoirs on human health can occur when eating fish, other food products made from raw materials obtained from polluted reservoirs; when using water contaminated with enteropathogenic bacteria and viruses or toxic chemicals for washing vegetables, fruits, berries, while relaxing on the shore of a reservoir, sports events, etc.

The consequences of the impact of polluted water in reservoirs on human health can be summarized as follows:

the quality of drinking tap water largely depends on the quality of water in a surface water body, which is a real or may be a potential source of centralized water supply;

pollution of water bodies leads to a reduction in food resources due to the inability to consume fish, fish products, other "seafood", which can be contaminated with various toxic chemicals: heavy metals, organochlorine pesticides, polychlorinated biphenyls, etc.;

polluted waters of reservoirs cannot be used for irrigation of agricultural land, as this hinders the development of agriculture. Such waters cannot also be used in animal husbandry and poultry farming;

loss of water due to pollution as a raw material resource for the national economy. Thus, cases of mass diseases and death of sheep on pastures located on islands near Great Britain are known. Animals have died from eating seaweed high in mercury and arsenic.

conclusions

The main sources of surface water pollution today are:

industrial enterprises;

· livestock complexes, farms and poultry farms;

thermal and nuclear power plants;

public utility companies;

storm drains from urban areas;

· Agriculture;

· water transport;

· precipitation;

· hydraulic structures, regulation of river flow and creation of reservoirs.

In a number of areas, water bodies are also polluted during the extraction of minerals and peat extraction. Behind recent decades Recreation has become a significant source of pollution of rivers and reservoirs, especially such types of it as mass bathing and small fleets.

The current level of wastewater treatment is such that even in waters that have undergone biological treatment, the content of nitrates and phosphates is sufficient for irreversible environmental changes in water bodies.

Of course, all of the above negatively affects human health and well-being and indicates that the problem of sanitary protection of water bodies is of both medical (hygienic) and national economic importance.

Bibliography

1. Martynov et al. Analysis of socio-economic factors affecting the state of biological diversity. Preparatory phase of the GEF project “Conservation of the biological diversity of Russia” (Appendix 1) - M., PAIMS, 1995-288 p., ill.

2. Journal "Ecological Norms. Rules. Information" No. 1, 2007

3. Badtiev Yu.S., Barkov V.A., Usov G.P. Bioindication of surface water bodies. // Ecology and industry of Russia. - 2003 - July. - S.24-26.

4. http://www.uzenbash.ru/okruzhajuscheaja-sreda/prirodnaja-sreda/14/

5. http://www.monolith. info/poleznaya-informatsiya/zagryaznenie-poverhnostnyih-vod.html

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Introduction

The relevance of research. Pollution of surface waters began in central Russia as early as the 16th century, when fields were fertilized with manure. Since then, agriculture has been the main water pollutant in the central regions of the country. In the more northern regions, timber rafting, especially mole rafting, played an important role, in which the logs sank and rotted in the water. With the development of industry and the growth of cities, the role of municipal and industrial pollution began to grow.

A sharp increase in pollution occurred in the twentieth century. A particular danger is associated with the coincidence of the period of growth in discharges of polluted wastewater and the centuries-old trend of increasing dryness of the climate, and a decrease in the water content of water bodies. Under these conditions, the concentrations of pollutants in solutions increase and, consequently, the degree of their harmful effects on natural systems and human health.

By the beginning of the 90s. quite a lot has been created in Russia a difficult situation. The water quality of most of the country's surface water bodies did not meet the established standards. The main substances polluting surface waters are oil products, phenols, easily oxidizable organic substances, copper and zinc compounds, ammonium and nitrate nitrogen.

The purpose of the work is to characterize the sources of water pollution.

To achieve this goal, we have solved the following tasks: to describe the main sources of pollution of freshwater land, to analyze the features of cleaning water bodies.

1. Sources of land surface water pollution

Rivers in their natural state act as drainage systems that collect runoff from the catchment area. Human economic activity is gradually turning rivers into sewers with a very high level of pollution (sometimes up to 100 MPC). And if the quantitative depletion of the planet's water resources does not threaten humanity in the near future, then the qualitative depletion of water resources is already evident today.

The main sources of pollution of natural waters are manufacturing enterprises chemical, oil, pulp and paper industries, electric power and mechanical engineering, ferrous and non-ferrous metallurgy, agriculture and public utilities. The amount of wastewater discharged into Russian water bodies in 2007 amounted to 59.3 km 3(about 3% of global wastewater).

Of this amount, up to 30 km are annually discharged into the rivers. 3polluted waters requiring at least 10-12-fold dilution. In order to guarantee the quality of water with a content of pollutants not higher than the MPC, the values ​​of the maximum allowable discharge of pollutants (MPD) have been established for industrial enterprises. In Russia, MPCs are exceeded for various indicators in all major water bodies. The main rivers of Russia - the Volga, Don, Kuban, Ob, Yenisei, Lena - are rated as “polluted” and in places “heavily polluted” in terms of water quality.

The total mass of pollutants (petroleum products, suspended solids, sulfates, chlorides, phenols, phosphorus compounds, fats, oils, organic substances, especially toxic heavy metals and synthetic surfactants, etc.) entering the country's natural water bodies together with wastewater, is estimated at 21 million tons.

The state of rivers is especially unfavorable in areas of populous megacities and large industrial centers, where pollution is caused by direct discharge of sewage and storm water from the surfaces of adjacent territories through collectors that are not equipped with treatment facilities, sewer manholes, etc.

The current level of wastewater treatment is such that even in waters that have undergone biological treatment, the content of nitrates and phosphates is sufficient for intensive eutrophication of water bodies. Heavy metals can be found in small but highly hazardous concentrations in treated but not completely treated wastewater, or in more concentrated form in groundwater at landfill sites.

One of the sources of pollutants entering the aquatic environment is dry and wet fallout from the atmosphere onto the surface of watersheds. Along with aerosols (mainly sulfur and nitrogen compounds) and dust, heavy metals, hazardous organic compounds, and radioactive substances also enter water bodies, surface and ground waters. Now it can be said with all obviousness that the main volume of pollution of the entire hydrosphere, in particular, more than 70% of the pollution of the World Ocean, is associated with terrestrial sources. Industry, construction, household and agriculture supply pollutants that pose a threat to the life of the ocean's biota.

Oil, metals, organochlorine compounds, garbage, plastics, radioactive waste slowly decompose and accumulate in organisms. Oil is the most persistent pollutant in ocean waters. Every year, from 6 to 10 million tons of oil enters the seas and oceans (Table 1). It is known that 1 ton of oil, spreading, forms a spot on the water surface 12 km 2. Heavy metal ions, pesticides and other toxicants that are dangerous to living organisms accumulate in oil films.

One of the main sources of pollution of surface and groundwater is agriculture - both agriculture and intensive animal husbandry. During floods, spring snowmelt and after heavy rains, many tons of pesticides and mineral fertilizers are washed off the surfaces of agricultural land with water.

Table 1. Sources of oil pollution of the hydrosphere (according to W. Stoner and B. Seeger)

Source of pollutionTotal amount, million tons/year Share, % Shipping Including ordinary transportation2.13 1.8334.9 30.0 Disasters0.34.9 River transport1.931.1 Atmospheric emissions0.69.8 Industrial wastes0.34.9 Natural sources0.69.8 Urban wastes0.34.9 Wastes from coastal oil refineries0.23. 2 Offshore oil production Including: normal operations accidents 0.08 0.02 0.061.3 0.3 0.98

For example, in Russia several million tons of fertilizers and up to 100 thousand tons of pesticides are used annually in the fields. Particularly dangerous are the discharges of wastewater from livestock complexes and poultry farms, where manure and waste are cleaned by hydraulic flushing without wastewater treatment. Overflowing manure storages periodically dump a huge amount of organic matter, leading to eutrophication of natural water bodies.

This phenomenon is associated with an excess supply of biogenic substances (mainly phosphorus and nitrogen compounds) to lakes, reservoirs, and river mouths, leading to the massive growth of aquatic plants and a rapid "bloom" of algae. Eutrophication causes a number of unfavorable geoecological consequences: deterioration of water quality, decrease in the recreational value of a reservoir, death of fish, blocking of canals and watersheds. The main sources of nitrogen and phosphorus are agriculture and municipal wastewater.

Groundwater, like other components of the environment, is polluted by human activities. Groundwater suffers from pollution from oil fields, mining enterprises, polluted wastewater filtration fields, dumps and dumps of metallurgical plants, storage facilities for chemical waste and fertilizers, livestock complexes, settlements not equipped with sewerage, etc. Pollutants are basically the same as for surface waters: oil products, phenols, heavy metals (copper, zinc, lead, cadmium, nickel, mercury), sulfates, chlorides, nitrogen compounds (with pollution intensity within 1 - 100 MPC).

In Russia, about four thousand groundwater deposits have been explored for domestic drinking, industrial and technical water supply and land irrigation, the operational reserves of which are 26.7 km 3/year. The degree of development of their reserves on average in the country does not exceed 33%. The largest areas of contaminated groundwater have been identified in the Moscow, Tula, Perm regions, in Tatarstan, Bashkortostan, as well as near the cities of Volgograd, Magnitogorsk, Kemerovo.

The population of Russia as a whole is not provided with water of adequate quality due to the unsatisfactory condition of both water bodies (surface and underground) and centralized water supply systems.

About 1/3 of the population use water from decentralized sources for drinking. An analysis of the water from such sources showed that about 50% of them do not meet the hygienic requirements for sanitary-chemical and bacteriological indicators. A particularly difficult situation has developed in the Arkhangelsk, Kaliningrad, Kaluga, Kursk, Tomsk and Yaroslavl regions, Primorsky Krai, Dagestan, and Kalmykia.

Providing all inhabitants of the Earth with high-quality drinking water is the most important global problem modernity. Another equally important problem is the rational use of water resources, saving water in all types of water consumption.

Reducing the scale of water pollution is the way to solve the problem of quantitative and qualitative depletion of the world's water resources.

The economics of the use of water resources needs to be revised. As long as the water around the world has low price, in many regions it is generally free. This leads to inefficient use of water resources and, consequently, to serious environmental problems.

2. Features of surface water pollution

There are two main categories of pollution sources for water bodies: sources of point pollution and diffuse pollution. The first category includes, for example, discharges from industrial enterprises and treatment facilities communal drains. The second category includes, for example, pollution associated with agriculture, such as water pollution by decay products of fertilizers and pesticides. Strategies for managing point and diffuse pollution are very different. In the first case, it is necessary to deal with each source, while in case of diffuse pollution, it is necessary to implement a management strategy for the entire river basin, or, more precisely, the state of the landscapes of the basin, especially anthropogenically transformed ones.

Strategies to improve water quality tend to start with point pollution and, with some success, then turn to diffuse pollution management. In Russia, so far the main attention, and even then insufficient, has been given to the control of point pollution.

Water pollutants and their indicators can also be divided into several groups that cause specific water quality problems in different types of water bodies and, accordingly, require different control strategies:

microbiological indicators related to human health (concentration of Escherichia coli as an indicator of the number of pathogenic bacteria, etc.);

suspended solids (total content, turbidity and transparency of water);

organic substances. Pollution indicators: dissolved oxygen, biochemical and chemical oxygen demand (VOD and COD), phosphates, chlorophyll-A;

biogenic substances (compounds of nitrogen and phosphorus);

basic ions (total solutes, electrical conductivity, pH, calcium, magnesium, sodium, potassium, chlorides, sulfates, bicarbonates, boron, fluorine, water hardness);

inorganic micro-pollutants (aluminum, arsenic, beryllium, cadmium, chromium, cobalt, copper, cyanides, hydrogen sulfide, iron, lead, lithium, manganese, mercury, molybdenum, nickel, selenium, vanadium, zinc);

organic micro-pollutants (or dioxins) (there are many of them: polychlorinated biphenyls, benzapyrene, pesticides, etc.; they are harmful even in very small concentrations; due to their low concentration, their determination is very difficult).

The main problems associated with the pollution of various water bodies are presented in Table. 2.

Table 2. Main water quality problems

Let us consider the main features of these problems. Infection with pathogens is a very important factor in the high morbidity and mortality from gastrointestinal diseases. It is directly dependent on the density of the population and the level of its socio-economic development, and therefore is more typical for developing countries. In developed countries, drinking water supplies are treated, while in developing countries, treatment is not always satisfactory, if at all.

Even in developed countries, pathogen contamination is not fully controlled, as we have just seen with cryptosporidiosis in the US. In developing countries, it is widespread downstream from cities and densely populated rural areas due to insufficient development of sewerage and water treatment systems. As a result, the index of pathogenic water pollution increases 3200 times within the city, reaching 24 million coli sticks per 100 ml of water. A high level of contamination with pathogens and organic substances is noted in the river. Ganges; carried out special program improve the condition of this great river of India.

Infection by pathogens and pollution by organic substances are interrelated. Organic substances are the largest group of pollutants, historically usually appearing first, at the very beginning of the river pollution process. They enter the water in dissolved or suspended form, mainly with sewerage or unregulated domestic sewage.

In some places, the pulp and paper and food industries also make a significant contribution. Geographic distribution pollution by organic substances generally coincides with the spread of pathogenic contamination. Rivers have a significant self-cleaning capacity due to the oxygen dissolved in water, the amount of which is constantly replenished from the atmosphere due to the turbulent regime of river flow.

When the flow of organic matter into the river begins to exceed its self-cleaning capacity, water pollution increases progressively. To solve the problem of water pollution by organic substances and pathogens, it is necessary to implement a set of measures. main role here is the reduction in the volume of pollution coming from the pool and, on the other hand, the construction of treatment facilities.

Suspended solids in river waters are mainly fine soil particles. The concentration of suspended sediments is an indicator of the degree of water erosion of the soil and, therefore, the state of the basin. Agriculture plays a significant role in this process. In general, ceteris paribus, the higher the area of ​​arable land, the greater the sediment runoff.

The total sediment runoff along the world's rivers is estimated at about 20 billion tons per year. Sediment transport within river basins is at least five times greater, approximately 100 billion tons. Human activities greatly increase sediment runoff, largely due to the disturbance of the natural state of the soil surface in the river basin. Anthropogenically increasing sediment runoff leads to deterioration of navigation conditions on rivers, siltation of reservoirs and irrigation systems. Fine soil particles carried in the form of sediments usually adsorb phosphorus compounds on their surface.

This is the same silt that r. The Nile brought every flood to the fields, keeping Egypt's soil fertile for thousands of years. After the construction of dams on rivers, almost all sediment accumulates in reservoirs, along with adsorbed phosphorus. This leads to a decrease in both soil fertility and fish productivity in the downstream of dams. Measures to reduce soil erosion in river basins at the same time control the movement of phosphorus in the basin. We again see a high degree of complexity of interconnections in the ecosphere and the leading role of water in the management of territorial systems.

It is accepted that natural waters are in a state of acidification if their acidity index (pH) is equal to or less than 5.0. Many processes in the ecosphere are determined by acid-base reactions, that is, they depend on the pH value. All biological processes in water bodies, such as algae growth, microorganism decay, nitrification and denitrification, are distinguished by their optimal pH value, usually in the range of 6-8. Changes in flora and fauna in aquatic ecosystems are an important indicator of acidification.

pollution water quality cleaning

3. Water purification

The most important technological measures for the rational use and protection of water resources are the improvement of production technologies, the introduction of non-waste technologies into practice. Currently, the current circulating water supply system, or water reuse, is being improved.

Since it is impossible to completely avoid water pollution, biotechnical measures for the protection of water resources are applied - forced purification of wastewater from pollution. The main cleaning methods are mechanical, chemical and biological.

During mechanical wastewater treatment, insoluble impurities are removed using gratings, sieves, grease (oil) traps, etc. Heavy particles are deposited in settling tanks. Mechanical cleaning can free water from undissolved impurities by 60-95%.

In chemical treatment, reagents are used that convert soluble substances into insoluble ones, bind them, precipitate and remove them from wastewater, which is purified by another 25-95%.

Biological treatment is carried out in two ways. The first is carried out on specially prepared filtration (irrigation) fields with equipped maps, main and distribution channels. Cleaning occurs in a natural way - by filtering water through the soil.

The organic filtrate is subjected to bacterial decomposition, exposure to oxygen, sunlight and is further used as a fertilizer. A cascade of settling ponds is also used, in which water self-purification occurs naturally.

The second accelerated method of wastewater treatment is carried out using special biofilters. Wastewater treatment is carried out by filtration through porous materials (gravel, crushed stone, sand and expanded clay), the surface of which is covered with a film of microorganisms. The cleaning process on biofilters is more intensive than on filtration fields.

Currently, almost no city can do without treatment facilities, and in urban conditions, all of these methods are used in combination, which gives a good effect.

Conclusion

Approximately 1/3 of them are industrial wastewater. It is believed that more than 500 thousand different substances enter the water bodies. Industrial and domestic waste containing salts of various metals, poisons, pesticides, fertilizers, detergents, and radioactive substances enter the waters. More than 2/3 polluting water systems oil comes from the dumping of waste oil products used by cars and machinery.

An analysis of the global water balance showed that 2,200 m3 are spent on all types of water use. 3 clean water in year. Until now, the growth in the quality of wastewater treatment plants lags behind the growth in water consumption.

However, the treatment problem is more serious, since even with the most advanced technology, including biological technology, all dissolved inorganic substances and up to 10% of organic pollutants remain in the treated wastewater.

Such water can again become suitable for household consumption only after it has been repeatedly diluted with pure natural water. Almost 20% of the world's fresh water resources are used to dilute wastewater.

Calculations for the beginning of the new millennium, assuming that water consumption rates will decrease, and treatment will cover all wastewater, showed that all the same, 30 - 35 thousand m3 will be required annually to dilute wastewater 3fresh water.

This means that the resources of the total world river flow will be close to exhaustion, and in many parts of the world they have already been exhausted. After all, 1 m 3treated waste water "spoils" 10 m 3river water, and untreated - 3-5 times more. The amount of fresh water is not decreasing, but its quality is dropping sharply, it becomes unsuitable for consumption.

Literature

1.Golubev G.N. Geoecology: Textbook - M.: Aspect-press, 2006. - 288 p.

2.Knyazeva V.P. Ecology. Fundamentals of restoration. - M., 2006. - 328 p.

.Komarova N.G. Geoecology and nature management. - M.: Academy, 2008. -192 p.

.Kostantinov V.M., Chelidze Yu.B. Ecological bases of nature management. - M.: Academy, 2006. - 208 p.

The main sources of pollution and clogging of water bodies are insufficiently treated wastewater from industrial and municipal enterprises, large livestock complexes, production waste from the development of ore to minerals, hydropower construction, water from mines, mines, waste from the processing and rafting of timber, discharges from water and railway transport, waste primary processing of flax, pesticides, etc. With the beginning of the navigation period, the pollution of the river fleet by ships increases.

Pollutants entering natural water bodies lead to qualitative changes in water, which are mainly manifested in changes in the physical properties of its chemical composition, in particular, the appearance of unpleasant odors, tastes, etc.; there are substances floating on the surface of the water and deposited at the bottom of the water.

Industrial wastewater is polluted mainly by industrial waste and emissions. Their quantitative and qualitative combination is diverse and depends on the industry, its technological processes, they are divided into two main groups: those containing inorganic impurities, including toxic ones, and those containing poisonous ones.

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

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

Oil and oil products at the present stage are the main pollutants of inland waters, waters and seas. World Ocean. Getting into water bodies, they create different forms of pollution: oil slick, pl. Lava on water, oil products dissolved or emulsified in water, settled to the bottom, heavy fractions, etc. At the same time, the smell, taste, color, surface tension, viscosity of water change, the content of ki snyu decreases, harmful organic substances appear, water acquires toxic properties and poses a threat not only to humans. 12 ml of oil makes a ton of water unfit for consumption.

Among industrial products, toxic synthetic substances occupy a special place in terms of their negative impact on the aquatic environment and living organisms. They are finding more and more applications. Anna is in industry, in transport, in public utilities. The concentration of these compounds in wastewater, as a rule, is 5-10 mg / l at. MPC-0.1 mg / l. These substances can form water a layer of foam, especially visible on the thresholds. Crossroads, gateways. The ability to foam in these substances appears already at a concentration of 1-2 mg / mg / l.

Phenol is a rather harmful pollution of industrial waters. It is found in the wastewater of many petrochemical plants. At the same time, the biological processes of reservoirs, the process of their self-purification, are sharply reduced, 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 of fry and adult fish. Fibers and other insoluble substances clog water and impair its physical and chemical properties. Alloys adversely affect fish and their food - invertebrates. Various tannins are released into the water from the decaying wood and bark. Resin and other extractive products decompose and absorb a lot of oxygen, causing the death of fish, especially juveniles and eggs. In addition, alloys 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 they are transferred along the food chain to other animals and humans. It has been established that the radioactivity of planktonic inhabitants is thousands of times higher than the water in which they live. Wastewater with increased radioactivity (100 curies per 1 liter or more) is subject to disposal in underground drainless pools and special reservoirs.

Population growth, the expansion of old and the emergence of new cities have significantly increased the flow of domestic wastewater into inland waters. These effluents have become a source of pollution of rivers and lakes with pathogenic bacteria and helminths. Synthetic detergents widely used in everyday life pollute water bodies to an even greater extent. They are also widely used in industry and agriculture. Chemical substances contained in them, entering rivers and lakes with sewage, have a significant impact on the biological and physical regime of water bodies. As a result, the ability of waters to saturate with oxygen decreases, the activity of bacteria, which mineralize organic matter and wine, is paralyzed.

Of serious concern is the pollution of water bodies with pesticides and mineral fertilizers, which fall from the fields along with jets of rain and melt water. In connection with the intensification of animal husbandry, the effluents of enterprises in this branch of agriculture are increasingly making themselves felt.

Waste water containing vegetable fibers, animal and vegetable fats, fecal matter, fruit and vegetable residues, waste from the leather and pulp and paper industries, sugar and breweries, enterprises of the meat and dairy, canning and confectionery industries are the cause of organic water pollution.

In wastewater, there are usually about 60% of substances of organic origin, the same category of organic includes biological (bacteria, viruses, fungi, algae) pollution in municipal, medical and sanitary waters and waste from tanneries and enterprises that wash wool.

Rivers are also polluted during rafting, during hydropower construction, and with the beginning of the navigation period, pollution by ships of the river fleet increases

Heated waste water. Thermal power plants and other industries cause "thermal pollution", which threatens with rather serious consequences: there is less oxygen in heated water, the thermal regime changes dramatically, which negatively affects the flora and fauna of water bodies, while favorable conditions arise for mass development in blue-green reservoirs. algae - the so-called "water bloom; water bloom".

In a number of regions, groundwater has been an important source of fresh water. Previously, they were considered the purest. But at present, as a result of human activities, many groundwater sources are also being polluted. Often this pollution is so great that the water in them has become undrinkable. Mankind consumes a huge amount of fresh water for its needs. Its main consumers are industry and agriculture. The most water-intensive industries are mining, steel, chemicals, petrochemicals, pulp and paper, and food. They take up to 70% of all water used by industry. The main consumer of fresh water is agriculture: 60-80% of all fresh water is used for its needs. In modern conditions, human needs for water for communal household needs are greatly increasing. The volume of water consumed for these purposes depends on the region and standard of living, ranging from 3 to 700 liters per person. From the analysis of water consumption over the past 5-6 decades, it follows that the annual increase in irretrievable water consumption, in which the used water is irretrievably lost to nature, is 4-5%. Forward-looking calculations show that while maintaining such rates of consumption and with a bang, taking into account population growth and production volumes, by 2100 humanity can exhaust all fresh water reserves. Already at the present time, not only the territories that nature has deprived of water resources are experiencing a lack of fresh water, but also many regions, until recently were considered favorable in this regard, at present, the need for fresh water is not met by 20% of the urban and 75% of the rural population of the planet planets.

Limited fresh water supplies are further reduced due to pollution. The main hazard is created by wastewater (industrial, agricultural and domestic), since a significant part of the water used is returned to water basins in the form of wastewater.

PLAN

Introduction ................................................ ............................................... 2

The water cycle................................................ ............................... 2

Surface waters .................................................................. ......................... 3

Groundwater .................................................................. ................................ 4

Water in human life .............................................................. .......................... 5

Water problems .............................................................. ................................... 7

Pollution................................................. ....................................... 10

Surface water pollution .................................................................. ..... 12

Groundwater pollution .................................................................. ............ 15

Water Ecology Goals............................................................... 16

Activities for the protection and conservation of water resources..... 19

Means of implementation ................................................................ ............... 23

a) Funding and cost estimates....................................................... 23

b) Scientific and technical means ............................................... ...... 24

c) Development of human resources............................................... ........ 25

d) Capacity building .............................................................. ................. 26

CONCLUSION................................................. ................................. 27

Introduction

Scientists have calculated that 97.5% of all water reserves on planet Earth are in the salt waters of the seas and oceans. In other words, fresh water makes up only 2.5% of the world's reserves.

If we take into account that 75% of fresh water is "frozen" in mountain glaciers and polar caps, another 24% is underground in the form of groundwater, and another 0.5% is "dispersed" in the soil in the form of moisture, it turns out that the most accessible and cheap water sources - rivers, lakes and other surface water bodies account for slightly more than 0.01% of the world's water reserves.

Taking into account the importance that water has for human life and all life on Earth, these figures clearly confirm the sacramental thesis that water is one of the most precious treasures of our planet.

The water cycle

As we remember from the lessons of natural history, water is in constant motion. Evaporating from the surface of reservoirs, soil, plants, water accumulates in the atmosphere and, sooner or later, falls out in the form of precipitation, replenishing reserves in the oceans, rivers, lakes, etc. Thus, the amount of water on Earth does not change, it only changes its forms - this is the water cycle in nature. Of all the precipitation that falls, 80% falls directly into the ocean. For us, the remaining 20% ​​that falls on land are of greatest interest, since most of the water sources used by man are replenished precisely due to this type of precipitation. Simply put, water that has fallen on land has two paths. Either it, gathering in streams, streams and rivers, ends up in lakes and reservoirs - the so-called open (or surface) sources of water intake. Or water, seeping through the soil and subsoil layers, replenishes groundwater reserves. Surface and ground water are the two main sources of water supply. Both of these water resources are interrelated and have both advantages and disadvantages as a source of drinking water.

surface water

Surface water quality depends on a combination of climatic and geological factors.

The main climatic factor is the amount and frequency of precipitation, as well as ecological situation in the region. Fallout precipitation carries with it a certain amount of undissolved particles, such as dust, volcanic ash, plant pollen, bacteria, fungal spores, and sometimes larger microorganisms. The ocean is a source of various salts dissolved in rainwater. It can detect chloride, sulfate, sodium, magnesium, calcium and potassium ions. Industrial emissions into the atmosphere also "enrich" the chemical palette, mainly due to organic solvents and oxides of nitrogen and sulfur, which are the cause of "acid rain". The chemicals used in agriculture also contribute.

Among the geological factors is the structure of the riverbed. If the channel is formed by limestone rocks, then the water in the river is usually clear and hard. If the channel is made of impermeable rocks, such as granite, then the water will be soft, but muddy due to the large amount of suspended particles of organic and inorganic origin.

In general, surface waters are characterized by relative softness, high organic content and the presence of microorganisms.

ground water

A significant part of the falling rain water, as well as melt water, seeps into the soil. There it dissolves the organic matter contained in the soil layer and is saturated with oxygen. Deeper are sandy, clayey, limestone layers. In them, organic matter is mostly filtered out, but the water begins to be saturated with salts and trace elements. In general, groundwater quality is affected by several factors.

1) Rainwater quality (acidity, salinity, etc.).

2) The quality of the water in the underwater tank. The age of such water can reach tens of thousands of years.

3) The nature of the layers through which water passes.

4) The geological nature of the aquifer.

As a rule, calcium, magnesium, sodium, potassium, iron and, to a lesser extent, manganese (cations) are contained in the most significant quantities in groundwater. Together with anions common in water - carbonates, bicarbonates, sulfates and chlorides - they form salts. Salt concentration depends on depth. In the most "old" deep waters, the concentration of salts is so high that they have a distinctly brackish taste. Most of the known mineral waters belong to this type. The highest quality water is obtained from limestone layers, but their depth can be quite large and getting to them is not a cheap pleasure. Ground waters are characterized by rather high mineralization, hardness, low content of organic matter and almost complete absence of microorganisms.

Water in human life

Water - at first glance, the simplest chemical compound two hydrogen atoms and one oxygen atom - is, without any exaggeration, the basis of life on Earth. It is no coincidence that scientists are looking for life forms on other planets. solar system so much effort goes into detecting traces of water.

Water itself has no nutritional value, but it is an indispensable part of all living things. Plants contain up to 90% of water, while in the body of an adult it is 60-65%, but this is an "average" of the total body weight. In more detail, bones are only 22% water, but the brain is already 75%, muscles are also 75% water (they contain about half of all body water), blood consists of water as much as 92%.

The primary role of water in the life of all living beings, including humans, is due to the fact that it is a universal solvent for a huge number of chemicals. Those. in fact, it is the environment in which all life processes take place.

Here is just a small and far from complete list of the "duties" of water in our body.

Regulates body temperature.

Humidifies the air while breathing.

Provides delivery of nutrients and oxygen to all cells of the body.

Protects and buffers vital organs.

Helps convert food into energy.

Helps nutrients to be absorbed by the organs.

Removes toxins and waste products of life processes.

A certain and constant water content is a necessary condition for the existence of a living organism. When the amount of water consumed and its salt composition change, the processes of digestion and assimilation of food, hematopoiesis, etc. are disrupted. Without water, it is impossible to regulate the body's heat exchange with the environment and maintain body temperature.

A person is extremely acutely aware of the change in the water content in his body and can live without it for only a few days. With a loss of water in an amount of less than 2% of body weight (1-1.5 l), a feeling of thirst appears, with a loss of 6-8%, a fainting state occurs, with 10% - hallucinations, swallowing disorders. Loss of 10-20% of water is life-threatening. Animals die when they lose 20-25% of water.

Depending on the intensity of work, external conditions (including climate), cultural traditions a person in total (with food) consumes from 2 to 4 liters of water per day. The average daily consumption is about 2-2.5 liters. It is from these figures that the World Health Organization (WHO) proceeds when developing recommendations on water quality.

Water problems

Fresh water reserves are a single resource. The long-term development of the world's freshwater resources requires a holistic approach to the use of these resources and recognition of the interdependence between the elements that make up freshwater supplies and determine its quality.

There are few regions in the world that are not affected by the loss of potential sources of fresh water supply, the deterioration of water quality and the pollution of surface and underground sources. The main problems affecting the water quality of rivers and lakes arise, depending on the circumstances, with varying degrees of severity as a result of inadequate treatment of domestic wastewater, poor control of industrial wastewater discharges, loss and destruction of catchment areas, irrational location of industrial enterprises, deforestation, uncontrolled fallow farming and unsustainable farming practices. This results in the leaching of nutrients and pesticides. The natural balance of aquatic ecosystems is disrupted and living freshwater resources are threatened.

In various circumstances, aquatic ecosystems are also affected by water development projects for agricultural development, such as dams, river flow transfer schemes, water facilities and irrigation projects. Erosion, siltation, deforestation and desertification lead to increased land degradation, and the creation of reservoirs in some cases adversely affects ecosystems. Many of these problems arise from environmentally destructive development patterns and a lack of public understanding and knowledge about the protection of surface and groundwater resources.

The degree of impact on the environment and human health is measurable, although in many countries the methods for implementing such control are very inadequate or not developed at all. There is a widespread misunderstanding of the relationship between development, management, rational use and purification of water resources and aquatic ecosystems. Where possible, it is essential to implement preventive measures in order to avoid later costly measures to restore, clean up and develop new water resources.

In most cases, water coming from a well, and often from a municipal water supply system, needs pre-treatment, the purpose of which is to bring the water quality up to current standards.

It is possible to judge the quality of water and its compliance or non-compliance with established standards only on the basis of the most complete chemical and bacteriological analysis. Only on the basis of analysis can a final conclusion be made about the problem or set of problems that will have to be dealt with.

The main troubles with water that users have to face are the following:

The presence in the water of undissolved mechanical particles, sand, suspensions, rust, as well as colloidal substances. Their presence in water leads to accelerated abrasive wear of plumbing and pipes, as well as to their clogging.

The presence of dissolved iron and manganese in water. Such water is initially transparent, but when settling or heating, it acquires a yellowish-brown color, which is the cause of rusty smudges on plumbing. With an increased iron content, the water also acquires a characteristic "ferrous" taste.

Hardness, which is determined by the amount of calcium and magnesium salts dissolved in water. With their high content, precipitation and the appearance of whitish stains on the surface of the bathtub, sink, etc. are possible. Calcium and magnesium salts, also called hardness salts, are the cause of the well-known scale.

Relatively harmless in the kettle, scale, being deposited on the walls of water heating devices (boilers, columns, etc.), as well as on the walls of pipes in the hot water line, disrupts the heat exchange process.

This leads to overheating of the heating elements, excessive consumption of electricity and gas. Scale deposits are responsible for up to 90% of water heater failures.

The presence in the water of an unpleasant taste, smell and color. These three parameters, which are commonly called organoleptic indicators, can be influenced by organic substances in the water, residual chlorine, and hydrogen sulfide.

bacteriological contamination. It is caused by the presence of various microbes or bacteria in the water. Some of them can pose a direct threat to human health and life, but even relatively safe bacteria in the course of their life activity emit organic substances that not only affect the organoleptic characteristics of water, but also, entering into chemical reactions (for example, with chlorine), can create toxic and carcinogenic compounds.

Naturally, the above list does not exhaust the whole variety of problems that arise with water, but introduces us to the main ones.

Pollution

Pollution of water bodies is understood as a decrease in their biospheric functions and economic significance as a result of the entry of harmful substances into them.

One type of water pollution is thermal pollution. Power plants, industrial enterprises often discharge heated water into a reservoir. This leads to an increase in the temperature of the water in it. With an increase in temperature in the reservoir, the amount of oxygen decreases, the toxicity of impurities polluting the water increases, and the biological balance is disturbed.

In polluted water, as the temperature rises, pathogenic microorganisms and viruses begin to multiply rapidly. Once in drinking water, they can cause outbreaks of various diseases.

In a number of regions, groundwater was an important source of fresh water. Previously, they were considered the purest. But at present, as a result of human activities, many sources of groundwater are also being polluted. Often this pollution is so great that the water from them has become undrinkable.

Mankind consumes a huge amount of fresh water for its needs. Its main consumers are industry and agriculture. The most water-intensive industries are mining, steel, chemicals, petrochemicals, pulp and paper, and food. They take up to 70% of all water used in industry. The main consumer of fresh water is agriculture: 60-80% of all fresh water is used for its needs.

In modern conditions, human needs for water for household needs are greatly increasing. The volume of water consumed for these purposes depends on the region and standard of living, ranging from 3 to 700 liters per person.

From the analysis of water use over the past 5-6 decades, it follows that the annual increase in irretrievable water consumption, in which the used water is irretrievably lost to nature, is 4-5%. Forward-looking calculations show that if such rates of consumption are maintained and taking into account population growth and production volumes, by 2100 mankind can exhaust all fresh water reserves.

Already at the present time, not only the territories that nature has deprived of water resources are experiencing a lack of fresh water, but also many regions that until recently were considered prosperous in this regard. Currently, the need for fresh water is not met by 20% of the urban and 75% of the rural population of the planet.

Human intervention in natural processes has affected even large rivers (such as the Volga, Don, Dnieper), changing the volume of transported water masses (river runoff) downward. Most of the water used in agriculture is used for evaporation and the formation of plant biomass and therefore is not returned to the rivers. Already now, in the most populated areas of the country, the flow of rivers has decreased by 8%, and in such rivers as the Don, Terek, Ural - by 11-20%. The fate of the Aral Sea is very dramatic, which, in fact, ceased to exist due to the excessive intake of the waters of the Syrdarya and Amudarya rivers for irrigation.

Limited fresh water supplies are further reduced due to pollution. Wastewater (industrial, agricultural and domestic) poses the main hazard, as a significant part of the used water is returned to water basins in the form of wastewater.

Surface water pollution

The water quality of most water bodies does not meet regulatory requirements. Long-term observations of the dynamics of surface water quality reveal a trend towards an increase in the number of sites with a high level of pollution (more than 10 MPC) and the number of cases of extremely high content (over 100 MPC) of pollutants in water bodies.

The state of water sources and centralized water supply systems cannot guarantee the required quality of drinking water, and in a number of regions ( Southern Urals, Kuzbass, some territories of the North) this state has reached a dangerous level for human health. Sanitary and epidemiological surveillance services constantly note high pollution of surface waters.

About 1/3 of the total mass of pollutants is introduced into water sources with surface and storm runoff from the territories of sanitary unimproved places, agricultural facilities and lands, which affects the seasonal, during the spring flood, deterioration in the quality of drinking water, annually noted in large cities, including including in Novosibirsk. In this regard, hyperchlorination of water is carried out, which, however, is unsafe for public health due to the formation of chlorine. organic compounds.

One of the main pollutants of surface waters is oil and oil products. Oil can get into the water as a result of its natural outflows in the areas of occurrence. But the main sources of pollution are associated with human activities: oil production, transportation, processing and use of oil as fuel and industrial raw materials.

Among industrial products, toxic synthetic substances occupy a special place in terms of their negative impact on the aquatic environment and living organisms. They are increasingly being used in industry, in transport, and in public utilities. The concentration of these compounds in wastewater, as a rule, is 5-15 mg/l at MPC - 0.1 mg/l. These substances can form a layer of foam in reservoirs, which is especially noticeable on rapids, rifts, locks. The ability to foam in these substances appears already at a concentration of 1-2 mg / l.

The most common pollutants in surface waters are phenols, easily oxidized organic substances, compounds of copper, zinc, and in some regions of the country - ammonium and nitrite nitrogen, lignin, xanthates, aniline, methyl mercaptan, formaldehyde, etc. A huge amount of pollutants is introduced into surface water with wastewater from ferrous and non-ferrous metallurgy enterprises, chemical, petrochemical, oil, gas, coal, timber, pulp and paper industries, agricultural and municipal enterprises, surface runoff from adjacent territories.

little danger to aquatic environment of metals are mercury, lead and their compounds.

Expanded production (without treatment facilities) and the use of pesticides in the fields lead to severe pollution of water bodies with harmful compounds. Pollution of the aquatic environment occurs as a result of the direct introduction of pesticides during the treatment of water bodies for pest control, the ingress of water flowing down from the surface of cultivated agricultural land into water bodies, when waste from manufacturing enterprises is discharged into water bodies, as well as as a result of losses during transportation, storage and partially with atmospheric precipitation.

Along with pesticides, agricultural effluents contain a significant amount of fertilizer residues (nitrogen, phosphorus, potassium) applied to the fields. In addition, large amounts of organic compounds of nitrogen and phosphorus enter with runoff from livestock farms, as well as with sewage. An increase in the concentration of nutrients in the soil leads to a violation of the biological balance in the reservoir.

Initially, in such a reservoir, the number of microscopic algae sharply increases. With an increase in the food supply, the number of crustaceans, fish and other aquatic organisms increases. Then there is the death of a huge number of organisms. It leads to the consumption of all the reserves of oxygen contained in the water, and the accumulation of hydrogen sulfide. The situation in the reservoir changes so much that it becomes unsuitable for the existence of any forms of organisms. The reservoir gradually "dies".

The current level of wastewater treatment is such that even in waters that have undergone biological treatment, the content of nitrates and phosphates is sufficient for intensive eutrophication of water bodies.

Eutrophication- enrichment of the reservoir with nutrients, stimulating the growth of phytoplankton. From this, the water becomes cloudy, benthic plants die, the concentration of dissolved oxygen decreases, fish and mollusks living at depth suffocate.

In many water bodies, the concentrations of pollutants exceed the MPCs established by sanitary and fish protection regulations.

Groundwater pollution

Not only surface but also groundwater is polluted. In general, the state of groundwater is assessed as critical and has a dangerous trend of further deterioration.

Groundwater (especially upper, shallow, aquifers), following other elements of the environment, is subject to the polluting influence of human economic activity. Groundwater suffers from pollution from oil fields, mining enterprises, filtration fields, sludge collectors and dumps of metallurgical plants, storage facilities for chemical waste and fertilizers, landfills, livestock complexes, and non-canalized settlements. There is a deterioration in water quality as a result of pulling up substandard natural waters in case of violation of the operation mode of water intakes. Areas of hotspots of groundwater pollution reach hundreds of square kilometers.

Substances polluting groundwater are dominated by: oil products, phenols, heavy metals (copper, zinc, lead, cadmium, nickel, mercury), sulfates, chlorides, nitrogen compounds.

The list of substances controlled in groundwater is not regulated, so it is impossible to get an accurate picture of groundwater pollution.

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At what stage of pregnancy does the breast swell?
At what stage of pregnancy does the breast swell?
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