Parting

Introduction: the essence and significance of water resources. The problem of water pollution

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 sources of pollution …………………...… 10

3.2. oxygen starvation as a factor of water pollution ……….… 12

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

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

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

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

4.1. Natural purification of reservoirs …………………………………..…… 21

4.2. Wastewater treatment methods …………………………………….…… 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. Endless 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 the 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 man, all plants and animals is well known. For many living beings, it serves as a habitat.

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

The demand for water is enormous and is increasing every year. The annual water consumption on the globe for all types of water supply is 3300-3500 km3. At the same time, 70% of all water consumption is used in agriculture.

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

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

On the present stage the following directions of rational use of water resources are determined: fuller use and expanded reproduction of fresh water resources; development of new technological processes to prevent water pollution and minimize fresh water consumption.

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 water. The total area of the Earth's oceans is 2.5 times the land area.

The total water reserves on Earth are 138.6 million km3. About 97.5% of the water is saline or highly mineralized, that is, it requires purification for a number of applications. The World Ocean accounts for 96.5% of the planet's water mass.

For a clearer idea of the scale of the hydrosphere, its mass should be compared 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 provided by the information presented in Table 1.

Table 1.

№	Name of objects	Distribution area in million cubic km	Volume, thousand cubic meters km	Share in world reserves, %%
1	World Ocean	361,3	1338000	96,5
2	The groundwater	134,8	23400	1,7
3	including underground	10530	0,76
fresh water
4	soil moisture	82,0	16,5	0,001
5	Glaciers and permanent snows	16,2	24064	1,74
6	underground ice	21,0	300	0,022
7	Lake water.
7a	fresh	1,24	91,0	0,007
76	salty	0,82	85.4	0,006
8	swamp water	2,68	11,5	0,0008
9	river water	148,2	2,1	0,0002
10	Water in the atmosphere	510,0	12,9	0,001
11	Water in organisms	1,1	0,0001
12	Total water supply	1385984,6	100,0
13	Total fresh water	35029,2	2,53

At present, the availability of water per person per day in different countries of the world is different. In a number of advanced economies, there is a threat of water scarcity. The scarcity of fresh water on earth is increasing in geometric progression. 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 distribution of productive forces, and very often the 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, for the production of 1 ton of cotton fabric, factories spend 250 m 3 of water. A lot of water is required by the chemical industry. So, about 1000 m 3 of water is spent on the production of 1 ton of ammonia.

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 in the future will increase by about 9-10 times.

Agriculture is one of the most significant water users. It is the largest water consumer in the water management system. For the cultivation of 1 ton of wheat, 1500 m 3 of water is required during the growing season, 1 ton of rice - more than 7000 m 3. The high productivity of irrigated land has stimulated a sharp increase in the area worldwide - it is now equal to 200 million hectares. Making up about 1/6 of the total area under crops, irrigated lands provide about half of agricultural production.

A special place in the use of water resources is occupied by water consumption for the needs of the population. Domestic 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 in the process of evaporation, part of the water used by man returns to the desalinated atmosphere. The other part (component, for example, in the water supply of cities and most industrial enterprises 90%) 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 withdrawal from natural waters in 1995, 96.9 km 3 were found. Including for the needs of the national economy, more than 70 km 3 were used, including for:

Industrial water supply - 46 km 3;

Irrigation - 13.1 km 3;

Agricultural water supply - 3.9 km 3;

Other needs - 7.5 km 3.

The needs of the industry were met by 23% due to the intake of water from natural water bodies and by 77% - by the system of circulating and re-sequential water supply.

2. Water resources of Russia

If we talk about Russia, then the basis of water resources is river runoff, which averages 4262 km 3 in terms of water content of the year, of which about 90% falls on the Arctic and Pacific Oceans. The basins of the Caspian and Azov Seas, where over 80% of Russia's population lives and where its main industrial and agricultural potential is concentrated, account for less than 8% of the total river runoff. The average long-term total flow of Russia is 4270 cubic meters. km/year, including 230 cubic meters from adjacent territories. km.

The Russian Federation as a whole is rich in fresh water resources: 28.5 thousand cubic meters per inhabitant. m per year, but its distribution over the territory is extremely uneven.

To date, the decrease in annual runoff major rivers In Russia, under the influence of economic activity, on average, ranges from 10% (Volga river) to 40% (Don, Kuban, Terek rivers).

The process of intensive degradation of small rivers in Russia continues: degradation of channels and siltation.

The total volume of water intake from natural water bodies amounted to 117 cubic meters. km, including 101.7 cubic meters. km of fresh water; losses are 9.1 cubic meters. km, used on the farm 95.4 cubic meters. km, including:

For industrial needs - 52.7 cubic meters. km;

For irrigation -16.8 cubic meters. km;

For household drinking -14.7 cubic km;

Us / x water supply - 4.1 cubic km;

For other needs - 7.1 cubic km.

In general, in Russia, the total volume of fresh water intake from water sources is about 3%; however, for a number of river basins, incl. Kuban, Don, the amount of water withdrawal reaches 50% or more, which exceeds the environmentally acceptable withdrawal.

In public utilities, water consumption averages 32 liters per day per person and exceeds the norm by 15-20%. The high value of specific water consumption is due to the presence of large water losses, which in some cities are up to 40% (corrosion and deterioration of water supply networks, leakage). The issue of the quality of drinking water is acute: a quarter of public utilities and a third of departmental water supply systems supply water without sufficient purification.

The main sources of pollution are wastewater from industrial and municipal enterprises, large livestock complexes and farms, stormwater runoff in cities, and rainwater washout of pesticides and fertilizers from fields. Waste water from industrial enterprises is formed at various stages of technological processes.

FROM oil producing and oil refining industry, transportation of oil and oil products is associated with the spread in water bodies of the most persistent pollutants - petroleum oils. Each ton of oil, spreading over the water surface, forms a film of light oils over an area of up to 12 km2, which hinders gas exchange with the atmosphere. Medium fractions of oil, mixing with water, form a poisonous emulsion that settles on the gills of fish. Heavy oils - fuel oil - settle to the bottom of reservoirs, causing toxic poisoning of fauna, death of fish.

Thermal power engineering- are heat emissions, the consequences of which can be: a constant increase in temperature in water bodies, overgrowth of water bodies with algae, an imbalance in oxygen, which poses a threat to the life of the inhabitants of rivers and lakes.

hydroelectric power plants- the construction of the dam leads to a significant flooding of the adjacent territories, a change in the hydrological and biological regimes of the rivers. In the shallow waters of reservoirs, "blooming" of water is widespread; they became the scene of invasion of blue-green algae. When dying, algae in the process of decomposition release phenol and other toxic substances. Fish leave such reservoirs, the water in them becomes unfit for drinking and even for swimming.

Wastewater pulp and paper industry They contain organic substances that absorb oxygen during the oxidation process, cause mass death of fish, and give the water an unpleasant taste and smell.

Waste of chemical and petrochemical industries, the mining industry clog the water with salts and solutions. Compounds of mercury, zinc, lead, arsenic, molybdenum and other heavy metals are especially dangerous, causing extremely dangerous human diseases that can accumulate in the organisms of the inhabitants of rivers, lakes, seas and oceans.

Machine-building complex- The main pollutants of wastewater are heavy metal ions, inorganic acids and alkalis, cyanides, and surfactants.

Synthetic surfactants(surfactants) and synthetic detergents (SMC) are highly toxic and resistant to biodegradation processes. Along with mechanical engineering, synthetic surfactants and SMS enter water bodies along with waste from the textile, fur, leather industry, and with domestic and municipal wastewater.

agricultural production pollution in many regions of the world surface water oem. Poisonous substances enter water bodies in the form of pesticides, used to control pests and diseases of agricultural crops. Wastewater from large livestock complexes is characterized by a high concentration of dissolved and undissolved pollutants.

dangerous pollutants are domestic wastewater and household waste, which contain 30 - 40% organic matter. The presence of a large amount of organic matter creates a stable environment in the soil, in which a special type of interstitial water appears, containing hydrogen sulfide, ammonia, and metal ions.

A special threat to the life of water bodies and human health is radioactive contamination. The disposal of liquid and solid radioactive waste was carried out in the seas and oceans by many countries that have a nuclear fleet and nuclear industry. The accumulation of radioactive waste dumped into the sea, as well as the accidents of nuclear ships and submarines, pose a danger not only to present, but also to future generations.

During the accident at the Chernobyl nuclear power plant, radioactive products entered the water bodies from the air and with effluents from the contaminated area into the basin of the river. Dnieper on the territory of Belarus, Russia, Ukraine. In this regard, there was a short-term excess of the established norms of water pollution in the river. Pripyat.

Intensive use of water resources entails that water loses its ability to self-purify. Self cleaning in the hydrosphere is associated with the circulation of substances. In reservoirs, it is provided by the combined activity of the organisms inhabiting them. Therefore, one of the most important tasks of rational water use is to maintain this ability.

From total wastewater discharged into surface water bodies, about 23% are normatively clean (discharged without treatment), 76% - normatively treated and 1% - polluted. Raw wastewater needs to be diluted with clean water multiple times. Normatively purified waters also contain impurities, and for their dilution, up to 6 - 12 m 3 of fresh water is required for each 1 m 3 .

More than 100 indicators of water quality are determined in hydrochemical laboratories: the content of floating impurities and suspended solids, the smell, taste and color of water, the composition and concentration of mineral impurities and oxygen dissolved in water, the composition and concentration of toxic and harmful substances, and its compliance with MPC standards is established.

In the Republic of Belarus, when assessing the degree of pollution of surface waters, the MPC standards for harmful substances are used, developed for:

household and drinking water supply (more than 400), for fishery reservoirs (more than 100), for recreational water sources-14

The quality of surface waters, if results are available for a sufficient number of indicators, can be assessed using the Water Pollution Index (WPI). WPI is calculated as 1/6 of the sum of the ratios of the average concentrations of the considered ingredients (dissolved oxygen, BOD 5 , ammonium nitrogen, nitrite nitrogen, oil products and phenols) to the maximum allowable concentrations of these ingredients

WPI=1/6 , where C i is the average concentration of the analyte for the observation period; MPC i is the maximum allowable concentration of the ingredient; 6 - the number of ingredients taken into account in the calculations.

As a result, the quality of water is determined depending on the class of its pollution:

the first is very pure water, WPI≤0.3;

the second is pure, WPI >0.3-1;

the third is moderately polluted, WPI>1-2.5;

the fourth is polluted, WPI>2.5-4;

the fifth is dirty, WPI>4-6;

the sixth is very dirty, WPI>6-10;

the seventh is extremely dirty, WPI>10.

The rivers of the Republic of Belarus are classified as moderately polluted. WPI=1-2

Most downloaded Svisloch-2.8-3.5, Berezina (Svetlogorsk = 2.1)

Dilution of wastewater is the process of mixing wastewater with the aquatic environment into which it is released, as a result, the concentration of impurities in wastewater is reduced. The intensity of the dilution process is qualitatively characterized by the multiplicity of dilution:

n = (FROM about - FROM in)/( FROM – FROM c), (6.5)

where FROM o is the concentration of pollutants in the discharged wastewater; FROM in and FROM- concentration of pollutants in the reservoir before and after release, respectively.

According to the World Health Organization, as a result of the consumption of poor quality water, about 500 million people fall ill every year, and child mortality reaches 5 million people. in year. Material damage is also expressed in a decrease in fish catches, additional costs for water supply to the population and industrial enterprises, and the construction of treatment facilities.

13. Main directions of protection and rational use
water resources

in effective ways wastewater treatment are mechanical, biological (biochemical), physical and chemical. To eliminate bacterial contamination, wastewater disinfection (disinfection) is used.

Mechanical- the most accessible method - is mainly used to remove undissolved and colloidal particles of organic or mineral origin from the waste liquid by simple settling. Mechanical cleaning devices include sand traps used to trap particles of mineral origin; settling tanks necessary to retain impurities organic origin in suspension.

Purification achieves the release of up to 60% of domestic wastewater, and up to 95% of undissolved impurities from industrial wastewater. It is considered completed if local conditions and in accordance with sanitary rules, wastewater can be discharged into a reservoir after disinfection. More often, mechanical cleaning is a preliminary stage before biological, or, more precisely, biochemical cleaning.

Biochemical methods purifications are based on the use of the vital activity of mineralizing microorganisms, which, multiplying, process and thereby transform complex organic compounds into simple, harmless mineral substances. Thus, it is possible to almost completely get rid of organic pollutants remaining in the water after mechanical cleaning. Facilities for biological or biochemical wastewater treatment can be divided into two main types. Structures in which biological treatment takes place under conditions close to natural (biological ponds, filtration fields, irrigation fields), and structures in which wastewater treatment is carried out under artificially created conditions (biological filters, aerotanks - special containers). Physicochemical methods of wastewater treatment include: electrochemical in electric fields, electrocoagulation, electroflotation, ion exchange, crystallization, etc.

All of the above methods of wastewater treatment have two ultimate goals: regeneration- extraction of valuable substances from wastewater and destruction- destruction of pollutants and removal of decay products from water. The most promising are such technological schemes, the implementation of which excludes the discharge of wastewater.

An effective method of combating water pollution is the introduction of recycled and recycled water supply at industrial enterprises. Circulating water supply is such water supply when water taken from a natural source is then recycled within the framework of applied technologies (cooling or being purified) without being discharged into a reservoir or sewer. At present, the volume of circulating and consistent use of water in relation to the total volume of water consumption for industrial needs in Belarus reaches 89%.

The problems of protection and rational use of water resources in the CIS countries are solved to a large extent through state regulation and, first of all, through a system of forecasting and planning. The main task is to maintain water resources in a condition suitable for the consumer and their reproduction in order to fully meet the needs of the national economy and the population in water.

The initial basis for forecasting and planning the use of water resources is the data of the water cadastre and accounting for water consumption according to the system of water management balances. Water cadastre - this is a systematic collection of information about water resources and water quality, as well as about water users and water consumers, the volumes of water they consume.

The forecast for the use of water resources is based on the calculation of the water management balance, which contains the resource and expenditure parts. The resource (incoming) part of the water management balance takes into account all types of water that can be consumed (natural runoff, inflow from reservoirs, groundwater, volume of return water). In the expenditure part of the water management balance, the need for water is determined by sectors of the national economy, taking into account the preservation of transit flow in rivers to ensure environmental requirements, the necessary sanitary and hygienic condition of water bodies

The main state enterprise responsible for water supply and wastewater treatment plants is Vodokanal.

To prevent pollution of water bodies, as well as to preserve the habitat of animal and plant organisms on lands adjacent to river channels or water areas, water protection zones, and within their limits, coastal strips of a strictly protected regime are distinguished. In order to protect water bodies that are used for domestic and drinking water supply, a sanitary protection zone is established at the water intake points.

Coastal strips are a protected area with a regime of limited economic activity. They prohibit: plowing land, horticulture and vegetable growing; grazing; storage and use of pesticides and mineral fertilizers; placement of gardening partnerships, recreation centers, tent camps, parking lots for vehicles and agricultural machinery; construction of buildings and structures, washing and Maintenance vehicles and technology.

In the short term, it is necessary to complete the creation of water protection zones for rivers, lakes and artificial reservoirs at a distance of up to 500 m from the water's edge in all small, medium and large water bodies (in particular, rivers more than 10 km long). All this should be accompanied by the establishment of strict land and water use regulations in the protection zones, a ban on the construction of production facilities that have emissions and effluents, landscaping, etc.

Similar information.

Water is the most common inorganic compound on our planet. In its natural state, water is never free from impurities. Various gases and salts are dissolved in it, there are suspended solid particles. 1 liter of fresh water can contain up to 1 gram of salts.

Most of the water is concentrated in the seas and oceans. Fresh water accounts for only 2%. Most of the fresh water (85%) is concentrated in the ice of the polar zones and glaciers.

Petroleum oils threaten the cleanliness of reservoirs the most. To remove oil, it is necessary to capture not only the film floating on the surface, but also the deposition of an oil emulsion.

Waste water from the pulp and paper industry is very dangerous as a pollutant. The effluents of these enterprises absorb oxygen due to the oxidation of organic substances, clog the water with insoluble substances and fibers, give the water an unpleasant taste and smell, change color, and promote the development of fungal growth along the bottom and banks.

Wastewater from various chemical plants especially pollute water bodies and have a detrimental effect on the development of aquatic organisms. CHP discharges are usually warmed up by 8-10°C higher than water from reservoirs. With an increase in the temperature of reservoirs, the development of micro- and macroplankton intensifies, the “blooming” of water occurs, its smell and color change.

The mole rafting of the forest strongly pollutes and clogs the rivers. Masses of floating forest inflict injuries on fish, block the way to spawning grounds, fish for the most part leaves their usual spawning grounds. Bark, branches, branches clog the bottom of reservoirs. From logs and wood waste, resin and other products harmful to the fish population are released into the water. Substances extracted from wood decompose in water, absorbing oxygen, causing the death of fish. Especially on the first day of the rafting, fish eggs and fry, as well as food invertebrates, die from a lack of oxygen.

The clogging of rivers is increased by the discharge of sawmill waste into them - sawdust, bark, etc., which accumulate mostly in backwaters and channels. Part of the forest is sinking, the number of logs is increasing from year to year. Rotting wood and bark poison the water, it becomes "dead".

The source of water pollution in many cases is municipal wastewater (sewerage, baths, laundries, hospitals, etc.).

The population is growing, old cities are expanding and new cities are appearing. Unfortunately, the construction of treatment facilities does not always keep pace with the pace of housing construction.

The situation is complicated by the fact that last years the content of biologically active and persistent impurities, such as new types of detergents, products of organic synthesis, radioactive substances, etc., has sharply increased in the composition of wastewater.

In a number of areas, groundwater pollution is observed due to seepage of pollution from the surface into aquifers. The greatest threat to the life of water bodies and human health is posed by radioactive waste from the nuclear industry. The sources of radioactive contamination of water bodies are plants for the purification of uranium ore and for the processing of nuclear fuel for reactors, nuclear power plants, reactors.

Currently, wastewater of increased radioactivity of the order of 100 curie/l and above is buried in underground tanks or pumped into underground drainless pools.

It has been established that sea water is capable of corroding containers, their dangerous contents spread in the water. The consequences of radioactive contamination from improper disposal of waste affected the Irish Sea, where plankton, fish, algae, and beaches were contaminated with radioactive isotopes.

The descent of radioactive waste into the seas and rivers, as well as their burial in the upper waterproof layers of the earth's crust, cannot be considered a reasonable solution to this important contemporary problem. Additional Scientific research methods of neutralization of radioactive contamination in water bodies.

In organisms of plants and animals, processes of biological concentration of radioactive substances occur along the food chains. Concentrated by small organisms, these substances then get to other animals, predators, where they form dangerous concentrations. The radioactivity of some planktonic organisms can be 1000 times higher than the radioactivity of water.

Some freshwater fish, which are one of the highest links in the food chain, are 20-30 thousand times more radioactive than the water in which they live.

Wastewater pollution is divided mainly into two groups: mineral and organic, including biological and bacterial.

Mineral pollution includes wastewater from metallurgical and machine-building enterprises, waste from the oil, oil processing and mining industries. These contaminants contain sand, clay and ore inclusions, slag, solutions of mineral salts, acids, alkalis, mineral oils, etc.

Organic water pollution is produced by urban fecal sewage, water from slaughterhouses, waste from leather, paper and pulp, breweries and other industries. Organic contaminants are of plant and animal origin. Vegetable residues include paper residues, vegetable oils, remains of fruits, vegetables, etc. The main chemical substance of this kind of pollution is carbon. Contaminants of animal origin include: physiological excretions of people, animals, remains of fatty and muscle tissues, adhesive substances, etc. They are characterized by a significant content of nitrogen.

Bacterial and biological contaminants are various living microorganisms: yeast and mold fungi, small algae and bacteria, including pathogens of typhus, paratyphoid, dysentery, helminth eggs, coming with excretions of people and animals, etc. Bacterial contamination of wastewater is characterized by the value of coli -titer, i.e., the smallest volume of water in millimeters, which contains one Escherichia coli (coli bacterium). So, if the coli-titer is 10, this means that 1 Escherichia coli is found in 10 ml. This type of pollution is characteristic of domestic water, as well as wastewater from slaughterhouses, tanneries, wool washes, hospitals, etc. The total volume of the bacterial mass is quite large: for every 1000 m 3 of wastewater - up to 400 liters.

Pollution mostly contains about 42% mineral substances and up to 58% organic.

When considering the composition of wastewater, one of the important concepts is the concentration of pollution, that is, the amount of pollution per unit volume of water, calculated in mg / l or g / m 3.

The concentration of wastewater pollution is determined chemical analyzes. Of great importance is the pH of wastewater, especially in the processes of their purification. The optimal environment for biological purification processes are waters with a pH of about 7-8. Domestic wastewater has a slightly alkaline reaction, industrial wastewater - from strongly acidic to strongly alkaline.

Pollution of water bodies is characterized by the following features:

The appearance of floating substances on the surface of the water and sedimentation at the bottom of the sediment;

Changes in the physical properties of water, such as: transparency and color, the appearance of odors and tastes;

Changes in the chemical composition of water (reactions, the amount of organic and mineral impurities, a decrease in oxygen dissolved in water, the appearance of toxic substances, etc.);

Changes in the types and numbers of bacteria and the emergence of pathogenic bacteria due to their entry with wastewater.

V.N. KetchHum (1967) developed a circuit (Fig. 1) in which, in in general terms distribution is shown and further fate pollution in relation to the marine environment, but it can be extrapolated to freshwater systems and estuaries.

Rice. one. Scheme of a qualitative picture of the impact of pollution on the hydrosphere

Water has an extremely valuable property of continuous self-renewal under the influence of solar radiation and self-purification. It consists in mixing contaminated water with its entire mass and in further process mineralization of organic substances and the death of introduced bacteria. Self-purification agents are bacteria, fungi and algae. It has been established that during bacterial self-purification, no more than 50% of bacteria remain after 24 hours, and 0.5% after 96 hours. The process of bacterial self-purification is greatly slowed down in winter, so that after 150 hours up to 20% of bacteria are still retained.

To ensure self-purification of polluted waters, they must be repeatedly diluted with clean water.

If the pollution is so great that self-purification of water does not occur, there are special methods and means for eliminating pollution from wastewater.

In industry, this is mainly the construction of workshops and general plant facilities for wastewater treatment, the improvement of the technological process of production and the construction of recycling plants for the extraction of valuable substances from wastewater.

In river transport, the most important is the fight against losses of oil products during loading, unloading and transportation on ships of the river fleet, equipping ships with containers for collecting polluted waters.

In case of timber rafting, the main methods of combating river clogging are strict adherence to the technology of timber rafting, cleaning river beds from sunken wood, stopping mole rafting of timber on rivers of fishery importance.

Pollution of water bodies- discharge or otherwise enter water bodies (surface and underground), as well as the formation of harmful substances in them that degrade water quality, limit their use or negatively affect the state of the bottom and banks of water bodies; anthropogenic introduction of various pollutants into the aquatic ecosystem, the impact of which on living organisms exceeds the natural level, causing their oppression, degradation and death.

There are several types of water pollution:

The most dangerous at present seems to be chemical water pollution due to the global scale of this process, the growing number of pollutants, among which there are many xenobiotics, i.e. substances alien to aquatic and near-water ecosystems.

Pollutants enter the environment in liquid, solid, gaseous and aerosol form. The ways of their entry into the aquatic environment are diverse: directly into water bodies, through the atmosphere with precipitation and in the process of dry fallout, through the catchment area with surface, subsoil and underground water runoff.

Sources of pollutants can be divided into concentrated, distributed, or diffuse, and linear.

Concentrated runoff comes from enterprises, public utilities and, as a rule, is controlled in terms of volume and composition by the relevant services and can be managed, in particular, through the construction of treatment facilities. Diffuse runoff comes irregularly from built-up areas, unequipped landfills and landfills, agricultural fields and livestock farms, as well as from atmospheric precipitation. This runoff is generally not controlled or regulated.

The sources of diffuse runoff are also zones of anomalous technogenic soil pollution, which systematically “feed” water bodies. hazardous substances. Such zones were formed, for example, after the Chernobyl accident. These are also lenses of liquid waste, such as oil products, burial sites solid waste whose waterproofing is broken.

It is almost impossible to control the flow of pollutants from such sources, the only way is to prevent their formation.

Global pollution is a sign of today. Natural and man-made flows of chemicals are comparable in scale; for some substances (primarily metals), the intensity of the anthropogenic turnover is many times greater than the intensity of the natural cycle.

Acid precipitation, formed as a result of nitrogen and sulfur oxides entering the atmosphere, significantly changes the behavior of microelements in water bodies and on their watersheds. The process of removal of microelements from soils is activated, acidification of water in reservoirs occurs, which negatively affects all aquatic ecosystems.

An important consequence of water pollution is the accumulation of pollutants in the bottom sediments of water bodies. Under certain conditions, they are released into the water mass, causing an increase in pollution with a visible absence of pollution from sewage.

Dangerous water pollutants include oil and oil products. Their sources are all stages of production, transportation and refining of oil, as well as the consumption of petroleum products. Tens of thousands of medium and large accidental spills of oil and oil products occur in Russia every year. A lot of oil gets into the water due to leaks in oil and product pipelines, on railways, in oil storage areas. Natural oil is a mixture of dozens of individual hydrocarbons, some of which are toxic. It also contains heavy metals (for example, molybdenum and vanadium), radionuclides (uranium and thorium).

The main process of transformation of hydrocarbons into natural environment is biodegradation. However, its speed is low and depends on the hydrometeorological situation. In the northern regions, where the main reserves are concentrated Russian oil, the rate of oil biodegradation is very low. Some oil and insufficiently oxidized hydrocarbons end up on the bottom of water bodies, where their oxidation rate is practically zero. Substances such as polyaromatic hydrocarbons of oil, including 3,4-benz (a) pyrene, exhibit increased stability in water. An increase in its concentration poses a real danger to the organisms of the aquatic ecosystem.

Another dangerous component of water pollution is pesticides. Migrating in the form of suspensions, they settle to the bottom of water bodies. Bottom sediments are the main reservoir for the accumulation of pesticides and other persistent organic pollutants, which ensures their long-term circulation in aquatic ecosystems. In food chains, their concentration increases many times over. Thus, compared with the content in the bottom silt, the concentration of DDT in algae increases 10 times, in zooplankton (crustaceans) - 100 times, in fish - 1000 times, in predatory fish - 10000 times.

A number of pesticides have structures unknown to nature and therefore resistant to biotransformation. These pesticides include organochlorine pesticides, which are extremely toxic and persistent in the aquatic environment and in soils. Their representatives, such as DDT, are prohibited, but traces of this substance are still found in nature.

Persistent substances include dioxins and polychlorinated biphenyls. Some of them have exceptional toxicity, which exceeds the most strong poisons. For example, the maximum permissible concentrations of dioxins in surface and ground waters in the USA are 0.013 ng/l, in Germany - 0.01 ng/l. They actively accumulate in food chains, especially in the final links of these chains - in animals. The highest concentrations were noted in fish.

Polyaromatic hydrocarbons (PAHs) enter the environment with energy and transport waste. Among them, 70–80% of the mass of emissions is occupied by benzo(a)pyrene. PAHs are classified as strong carcinogens.

Surface-active substances (surfactants) are usually not toxicants, but form a film on the surface of the water that disrupts gas exchange between water and the atmosphere. Phosphates, which are part of surfactants, cause eutrophication of water bodies.

The use of mineral and organic fertilizers leads to pollution of soils, surface and ground waters with compounds of nitrogen, phosphorus, microelements. Pollution with phosphorus compounds is the main cause of eutrophication of water bodies, the greatest threat to the biota of water bodies is borne by blue-green algae, or cyanobacteria, which multiply in large quantities in the warm season in water bodies subject to eutrophication. With the death and decomposition of these organisms, acute toxic substances- cyanotoxins. About 20% of all phosphorus pollution of water bodies enters water from agrolandscapes, 45% is provided by animal husbandry and municipal wastewater, more than a third - as a result of losses during transportation and storage of fertilizers.

Mineral fertilizers contain a large "bouquet" of trace elements. Among them are heavy metals: chromium, lead, zinc, copper, arsenic, cadmium, nickel. They can adversely affect the organisms of animals and humans.

A huge number of existing anthropogenic sources of pollution and numerous ways for pollutants to enter water bodies make it practically impossible to completely eliminate pollution of water bodies. Therefore, it was necessary to determine indicators of water quality, which ensures the safety of water use by the population and the stability of aquatic ecosystems. The establishment of such indicators is called standardization of water quality. In sanitary and hygienic regulation, the impact of hazardous concentrations of chemicals in water on human health is at the forefront, while in environmental regulation, protection of living organisms of the aquatic environment from them is put at the forefront.

The indicator of maximum permissible concentrations (MAC) is based on the concept of the threshold for the action of a pollutant. Below this threshold, the concentration of a substance is considered safe for organisms.

To distribute water bodies by the nature and level of pollution allows the classification, which establishes four degrees of pollution of a water body: permissible (1-fold excess of MPC), moderate (3-fold excess of MPC), high (10-fold excess of MPC) and extremely high (100 -fold excess of MPC).

Environmental regulation is designed to ensure the sustainability and integrity of aquatic ecosystems. The use of the “weak link” principle of an ecosystem makes it possible to estimate the concentration of pollutants that are acceptable for the most vulnerable component of the system. This concentration is accepted as acceptable for the entire ecosystem as a whole.

The degree of pollution of land waters is controlled by the system of State monitoring of water bodies. In 2007, sampling by physical and chemical indicators with simultaneous determination of hydrological indicators was carried out at 1716 points (2390 sections).

In the Russian Federation, the problem of providing the population with benign drinking water remains unresolved. The main reason for this is the unsatisfactory condition of the water supply sources. Rivers such as

Pollution of aquatic ecosystems leads to a decrease in biodiversity and impoverishment of the gene pool. This is not the only, but an important reason for the decline in biodiversity and abundance of aquatic species.

Protection of natural resources and ensuring the quality of natural waters is a task of national importance.

The Decree of the Government of the Russian Federation dated August 27, 2009 No. 1235-r approved the Water Strategy of the Russian Federation for the period up to 2020. It states that in order to improve the quality of water in water bodies, restore water ecosystems and the recreational potential of water bodies, the following tasks need to be solved:

To solve this problem, legislative, organizational, economic, technological measures are needed, and most importantly, political will aimed at solving the formulated tasks.

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Introduction

1. The concept of the aquatic environment

2.1 Inorganic pollution

2.2 Organic pollution

3. Methods for protecting water resources

Conclusion

Bibliography

Introduction

The 20th century is characterized by an intensive growth of the world's population and the development of urbanization. Giant cities with a population of more than 10 million people appeared.

The development of industry, transport, energy, industrialization of agriculture have led to the fact that the anthropogenic impact on the environment has assumed a global character.

Increasing the effectiveness of measures to protect the environment is associated primarily with the widespread introduction of resource-saving, low-waste and non-waste technological processes, and a decrease in air and water pollution.

Environmental protection is a very multifaceted problem, which is dealt with, in particular, by engineering and technical workers of almost all specialties that are associated with economic activities in settlements and industrial enterprises, which can be a source of pollution mainly of air and water.

This topic is very relevant at the present time, since the problem of water pollution is very acute all over the world.

The purpose of the work is to consider water as a source of life. Tasks to consider:

1. The concept of the aquatic environment

2. Chemical pollution of natural waters

3. Organic pollution

4. Inorganic pollution of the aquatic environment

5. Methods for protecting water resources

1. The concept of the aquatic environment

The aquatic environment includes surface and ground waters.

Surface waters are mainly concentrated in the ocean, with a content of 1 billion 375 million cubic kilometers - about 98% of all water on Earth. The surface of the ocean (water area) is 361 million square kilometers. It is about 2.4 times more area land area, occupying 149 million square kilometers. The water in the ocean is salty, and most of it (more than 1 billion cubic kilometers) retains a constant salinity of about 3.5% and a temperature approximately equal to 3.7 o C. Notable differences in salinity and temperature are observed almost exclusively in the surface layer of water, as well as in marginal and especially in mediterranean seas. The content of dissolved oxygen in water decreases significantly at a depth of 50-60 meters. Kormilitsyn V.I. Fundamentals of ecology. - M. Interstil, 2001. -74s.

Groundwater can be saline, brackish (lower salinity) and fresh; existing geothermal waters have an elevated temperature (more than 30`C). For the production activities of mankind and its household needs, fresh water is required, the amount of which is only 2.7% of the total volume of water on Earth, and a very small share of it (only 0.36%) is available in places that are easily accessible for extraction.

Most of the fresh water is found in snow and freshwater icebergs found in areas primarily in the Antarctic Circle. The annual global river flow of fresh water is 37.3 thousand cubic kilometers. In addition, a part of groundwater equal to 13 thousand cubic kilometers can be used. Fedtsov VG, Druzhlev L. Ecology and economics of environmental management. - M.: RDL, 2003. -194p.

Unfortunately, most of the river flow in Russia, amounting to about 5,000 cubic kilometers, falls on the marginal and sparsely populated northern territories.

In the absence of fresh water, salty surface or underground water is used, producing its desalination or hyperfiltration: it is passed under a large pressure drop through polymer membranes with microscopic holes that trap salt molecules. Both of these processes are very energy intensive, therefore, the proposal is of interest, which consists in using freshwater icebergs (or parts of them) as a source of fresh water, which for this purpose are towed along the water to shores that do not have fresh water, where they organize their melting.

According to the preliminary calculations of the developers of this proposal, the production of fresh water will be about half as energy-intensive as compared to desalination and hyperfiltration. An important circumstance inherent in the aquatic environment is that it is mainly transmitted through it infectious diseases(approximately 80% of all diseases). However, some of them, such as whooping cough, chickenpox, tuberculosis, are also transmitted through the air.

To combat the spread of disease through the aquatic environment, the World Health Organization (WHO) has declared the current decade the decade of drinking water.

Fresh water resources exist thanks to the eternal water cycle. As a result of evaporation, a gigantic volume of water is formed, reaching 525 thousand km per year. (Due to font problems, water volumes are indicated without cubic meters: 86% of this amount falls on the salt waters of the World Ocean and inland seas - the Caspian, Aral, etc.; the rest evaporates on land, and half is due to the transpiration of moisture by plants. Every year a layer of water evaporates about 1250 mm thick.Part of it again falls with precipitation into the ocean, and part is carried by winds to land and here feeds rivers and lakes, glaciers and groundwater.Natural distiller is powered by solar energy and takes about 20% of this energy.

Only 2% of the hydrosphere is fresh water, but they are constantly renewed. The rate of renewal determines the resources available to mankind. Most of the fresh water - 85% - is concentrated in the ice of the polar zones and glaciers. The rate of water exchange here is less than in the ocean, and is 8000 years. Surface water on land is renewed about 500 times faster than in the ocean. Even faster, in about 10-12 days, the waters of the rivers are renewed. Greatest practical value for humanity have fresh water rivers. Kormilitsyn V.I. Fundamentals of ecology. - M. Interstil, 2001. -226s.

Rivers have always been a source of fresh water. But in the modern era, they began to transport waste. Waste in the catchment area flows down the riverbeds into the seas and oceans. Most of the used river water is returned to rivers and reservoirs in the form of wastewater. So far, the growth of wastewater treatment plants has lagged behind the growth in water consumption. And at first glance, this is the root of evil. In fact, everything is much more serious. Even with the most advanced treatment, including biological treatment, all dissolved inorganic substances and up to 10% of organic pollutants remain in the treated wastewater. Such water can again become suitable for consumption only after repeated dilution of pure water. natural water. And here, for a person, the ratio of the absolute amount of wastewater, even if it is purified, and the water flow of rivers is important.

The global water balance has shown that 2,200 km of water per year is spent on all types of water use. Almost 20% of the world's fresh water resources are used to dilute wastewater. Calculations for 2000, assuming that water consumption rates will decrease and treatment will cover all wastewater, showed that 30-35 thousand km of fresh water will still be needed annually to dilute wastewater. 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 km of treated waste water "spoils" 10 km of river water, and not treated - 3-5 times more. The amount of fresh water does not decrease, but its quality drops sharply, it becomes unsuitable for consumption. Titenberg T. Economics of environmental management and environmental protection. - M.: OLMA-PRESS, 2001. -239p.

Mankind will have to change the strategy of water use. Necessity forces us to isolate the anthropogenic water cycle from the natural one. In practice, this means a transition to a recirculating water supply, to a low-water or low-waste, and then to a "dry" or waste-free technology, accompanied by a sharp decrease in the volume of water consumption and treated wastewater.

Fresh water reserves are potentially large. However, in any part of the world, they can be depleted due to unsustainable water use or pollution. The number of such places is growing, covering entire geographic areas. The need for water is not met by 20% of the urban and 75% of the rural population of the world. The volume of water consumed depends on the region and standard of living, and ranges from 3 to 700 liters per day per person. Water consumption by industry also depends on the economic development of the area. For example, in Canada, the industry consumes 84% of the total water intake, and in India - 1%. The most water-intensive industries are steel, chemical, petrochemical, pulp and paper, and food. They take almost 70% of all water used in industry. On average, industry consumes about 20% of all water consumed in the world. The main consumer of fresh water is agriculture: 70-80% of all fresh water is used for its needs. Irrigated agriculture occupies only 15-17% of the area of agricultural land, and provides half of all production. Almost 70% of the world's cotton crops are supported by irrigation.

2. Chemical pollution of natural waters

2.1 Inorganic pollution

Fresh water bodies are polluted mainly as a result of the discharge of sewage into them from industrial enterprises and settlements. As a result of wastewater discharge, physical properties water (temperature rises, transparency decreases, color, tastes, odors appear); floating substances appear on the surface of the reservoir, and sediment forms at the bottom; changes chemical composition water (the content of organic and inorganic substances increases, toxic substances appear, the oxygen content decreases, the active reaction of the environment changes, etc.); the qualitative and quantitative bacterial composition changes, pathogenic bacteria appear.

Polluted reservoirs become unsuitable for drinking, and often for technical water supply; lose their fishery importance, etc. The general conditions for the release of sewage of any category into surface water bodies are determined by their national economic significance and the nature of water use.

After the release of wastewater, some deterioration in the quality of water in reservoirs is allowed, but this should not noticeably affect his life and the ability to further use reservoir as a source of water supply, for cultural and sporting events, fishery purposes. Nature management. - M.: Dashkov and K., 2003. -342s.

Supervision over the fulfillment of the conditions for the discharge of industrial wastewater into water bodies is carried out by sanitary and epidemiological stations and basin departments.

The water quality standards for reservoirs of domestic and drinking cultural and domestic water use establish the quality of water for reservoirs for two types of water use: the first type includes sections of reservoirs used as a source for centralized or non-centralized domestic and drinking water supply, as well as for water supply to enterprises Food Industry; to the second type - sections of reservoirs used for swimming, sports and recreation of the population, as well as those located within the boundaries of settlements.

The assignment of water bodies to one or another type of water use is carried out by the bodies of the State Sanitary Supervision, taking into account the prospects for the use of water bodies.

The water quality standards for water bodies given in the rules apply to sites located on flowing water bodies 1 km upstream of the nearest water use point, and on stagnant water bodies and reservoirs 1 km on both sides of the water use point.

Much attention is paid to the prevention and elimination of pollution of the coastal areas of the seas.

Sea water quality standards, which must be ensured when discharging wastewater, refer to the water use area within the allotted boundaries and to sites at a distance of 300 m away from these boundaries. When using the coastal areas of the seas as a receiver of industrial wastewater, the content of harmful substances in the sea should not exceed the MPC established for sanitary-toxicological, general sanitary and organoleptic limiting indicators of harmfulness. At the same time, the requirements for the discharge of wastewater are differentiated in relation to the nature of water use. The sea is considered not as a source of water supply, but as a medical, health-improving, cultural and household factor.

Pollutants entering rivers, lakes, reservoirs and seas make significant changes to the established regime and disrupt the equilibrium state of aquatic ecological systems.

As a result of the processes of transformation of substances polluting water bodies, occurring under the influence of natural factors, in water sources there is a complete or partial restoration of their original properties. In doing so, they may form secondary products the breakdown of contaminants that adversely affect water quality.

Self-purification of water in reservoirs is a set of interrelated hydrodynamic, physicochemical, microbiological and hydrobiological processes leading to the restoration of the original state of a water body.

Due to the fact that wastewater from industrial enterprises may contain specific contaminants, their discharge into the city drainage network is limited by a number of requirements. Industrial wastewater released into the drainage network should not: disrupt the operation of networks and structures; have a destructive effect on the material of pipes and elements of treatment facilities; contain more than 500 mg/l of suspended and floating substances; contain substances that can clog networks or deposit on pipe walls; contain combustible impurities and dissolved gaseous substances capable of forming explosive mixtures; contain harmful substances that prevent biological wastewater treatment or discharge into a reservoir; have a temperature above 40 C.

Industrial wastewater that does not meet these requirements must be pre-treated and only then discharged into the city drainage network.

The water cycle, this long way of its movement, consists of several stages: evaporation, cloud formation, rainfall, runoff into streams and rivers, and again evaporation. Throughout its path, water itself is able to be cleaned of contaminants that enter it - decay products of organic substances, dissolved gases and minerals, suspended solids. In places with a large concentration of people and animals, natural clean water is usually not enough, especially if it is used to collect sewage and transfer it away from settlements.

If there is not much sewage in the soil, soil organisms recycle them, reusing nutrients, and already clean water seeps into neighboring watercourses. But if the sewage immediately enters the water, they rot, and oxygen is consumed for their oxidation. The so-called biochemical oxygen demand is created. The higher this requirement, the less oxygen remains in the water for living microorganisms, especially for fish and algae. Sometimes, due to lack of oxygen, all living things die.

Water becomes biologically dead - only anaerobic bacteria remain in it; they thrive without oxygen and in the course of their life they emit hydrogen sulfide, a poisonous gas with a specific smell rotten eggs. The already lifeless water acquires a putrid smell and becomes completely unsuitable for humans and animals.

This can also happen with an excess of substances such as nitrates and phosphates in the water; they enter the water from agricultural fertilizers in the fields or from sewage contaminated with detergents.

These nutrients stimulate the growth of algae, algae begin to consume a lot of oxygen, and when it becomes insufficient, they die. IN natural conditions the lake, before silting up and disappearing, there are about 20 thousand. years.

An excess of nutrients accelerates the aging process, or introphication, and reduces the life of the lake, making it also unattractive. Oxygen is less soluble in warm water than in cold water.

Some businesses, especially power plants, consume huge amounts of water for cooling purposes. The heated water is discharged back into the rivers and further disrupts the biological balance of the water system. Reduced oxygen content prevents the development of some living species and gives an advantage to others.

But these new, heat-loving species also suffer greatly as soon as water heating stops. Organic waste, nutrients and heat interfere with the normal development of freshwater ecosystems only when they overload those systems.

But in recent years, ecological systems have been bombarded with huge quantities of absolutely alien substances, from which they know no protection. Agricultural pesticides, metals and chemicals from industrial wastewater have managed to enter the aquatic food chain with unpredictable consequences. Species at the beginning of the food chain can accumulate these substances at dangerous levels and become even more vulnerable to other harmful effects. Polluted water can be purified.

Under favorable conditions, this occurs naturally in the process of the natural water cycle. But polluted river basins, lakes, etc. - It takes much longer to recover. To natural systems managed to recover, it is necessary, first of all, to stop the further flow of waste into the rivers.

Industrial emissions not only clog, but also poison wastewater. And the effectiveness of expensive devices for purifying such waters has not yet been sufficiently studied.

Despite everything, some municipalities and industrial enterprises still prefer to dump waste into neighboring rivers and are very reluctant to give it up only when the water becomes completely unusable or even dangerous. Titenberg T. Economics of environmental management and environmental protection. - M.: OLMA-PRESS, 2001. -326s.

In its endless cycle, water either captures and carries a lot of dissolved or suspended substances, or is cleared of them. Many of the impurities in the water are natural and get there with rain or groundwater. Some of the pollutants associated with human activities follow the same path. Smoke, ash and industrial gases, together with rain, fall to the ground; chemical compounds and sewage introduced into the soil with fertilizers enter the rivers with groundwater. Some waste follows artificially created paths - drainage ditches and sewer pipes. These substances are usually more toxic but easier to control than those carried in the natural water cycle.

Every body of water or water source is associated with its surroundings. external environment. It is influenced by the conditions for the formation of surface or underground water runoff, various natural phenomena, industry, industrial and municipal construction, transport, economic and domestic human activities. The consequence of these influences is the introduction of new, unusual substances into the aquatic environment - pollutants that degrade water quality. Pollution entering the aquatic environment is classified in different ways, depending on the approaches, criteria and tasks. So, usually allocate chemical, physical and biological pollution.

Chemical pollution is a change in natural chemical properties water due to an increase in the content of harmful impurities in it, both inorganic (mineral salts, acids, alkalis, clay particles) and organic nature (oil and oil products, organic residues, surfactants, pesticides).

The main inorganic (mineral) pollutants of fresh and marine waters are a variety of chemical compounds that are toxic to the inhabitants of the aquatic environment. These are compounds of arsenic, lead, cadmium, mercury, chromium, copper, fluorine. Most of them end up in water as a result of human activities. Heavy metals are absorbed by phytoplankton and then transferred through the food chain to more highly organized organisms.

In addition to the substances listed in the table, hazardous pollutants of the aquatic environment include inorganic acids and bases, which cause a wide range of pH of industrial effluents (1.0 - 11.0) and can change the pH of the aquatic environment to values of 5.0 or above 8.0, while fish in fresh and sea water can exist only in the range of pH 5.0 - 8.5.

Among the main sources of pollution of the hydrosphere with minerals and biogenic elements, food industry enterprises and agriculture should be mentioned.

Wastes containing mercury, lead, copper are localized in separate areas off the coast, but some of them are carried far beyond the territorial waters. Mercury pollution significantly reduces the primary production of marine ecosystems, inhibiting the development of phytoplankton. Wastes containing mercury usually accumulate in the bottom sediments of bays or river estuaries. Its further migration is accompanied by the accumulation of methyl mercury and its inclusion in the trophic chains of aquatic organisms Lukyanchikov N.N., Portavny I.M. Economics and organization of nature management. - M.: ENITI-DANA, 2002. -135p..

2.2 Organic pollution

Among those brought into the ocean from land soluble substances, great importance for the inhabitants of the aquatic environment, they have not only mineral, biogenic elements, but also organic residues. The removal of organic matter into the ocean is estimated at 300 - 380 million tons/year. Wastewater containing suspensions of organic origin or dissolved organic matter adversely affects the condition of water bodies. When settling, the suspensions flood the bottom and delay the development or completely stop the vital activity of these microorganisms involved in the process of water self-purification.

When these sediments rot, harmful compounds and toxic substances, such as hydrogen sulfide, can be formed, which lead to pollution of all water in the river. The presence of suspensions also makes it difficult for light to penetrate deep into the water and slows down the processes of photosynthesis. Kaznacheev V.P., Prokhorov B.B., Visharenko V.S. Human ecology and city ecology: an integrated approach // Human ecology in large cities 1988. - No. 2. - p. 25-28

One of the main sanitary requirements for water quality is the content of the required amount of oxygen in it. Harmful effects have all the pollution, which, one way or another, contribute to the reduction of oxygen in the water.

Surfactants - fats, oils, lubricants - form a film on the surface of the water, which prevents gas exchange between water and the atmosphere, which reduces the degree of saturation of water with oxygen.

A significant amount of organic matter, most of which is not characteristic of natural waters, is discharged into rivers along with industrial and domestic wastewater. Increasing pollution of water bodies and drains is observed in all industrial countries.

Due to the rapid pace of urbanization and the somewhat slow construction of sewage treatment plants or their unsatisfactory operation, water basins and soil are polluted with household waste. Pollution is especially noticeable in slow-flowing or stagnant water bodies (reservoirs, lakes).

Decomposing in the aquatic environment, organic waste can become a medium for pathogenic organisms.

Water contaminated with organic waste becomes almost unsuitable for drinking and other needs. Household waste is dangerous not only because it is a source of some human diseases (typhoid fever, dysentery, cholera), but also because it requires a lot of oxygen for its decomposition.

If domestic wastewater enters the reservoir in very large quantities, then the content of soluble oxygen may drop below the level necessary for the life of marine and freshwater organisms.

3. Methods for protecting water resources

Over the past decades, industrial and municipal effluents have become an increasingly significant part of the fresh water cycle. About 600-700 cubic meters are consumed for industrial and domestic needs. km of water per year. Of this volume, 130-150 cubic meters are irretrievably consumed. km, and about 500 cubic meters. km of waste, the so-called waste water is discharged into rivers, lakes and seas. An important place in the protection of water resources from qualitative depletion belongs to treatment facilities. Treatment facilities are different types depending on the main method of disposal of sewage. With the mechanical method, insoluble impurities are removed from wastewater through a system of settling tanks and various kinds of traps. In the past, this method has found the widest application for the treatment of industrial effluents. The essence of the chemical method lies in the fact that reagents are introduced into the wastewater treatment plants. They react with dissolved and undissolved contaminants and contribute to their precipitation in sumps, from where they are mechanically removed. But this method is not suitable for treating wastewater containing a large number of various pollutants. The electrolytic (physical) method is used to treat industrial effluents of complex composition. With this method, an electric current is passed through industrial waste, which leads to the precipitation of most pollutants. The electrolytic method is very efficient and requires relatively little investment in the construction of treatment plants. In our country, in the city of Minsk, a whole group of factories with the help of this method has achieved very high degree wastewater treatment.

When cleaning domestic wastewater, the biological method gives the best results. In this case, for the mineralization of organic pollutants, aerobic biological processes carried out by microorganisms. The biological method is used both in conditions close to natural and in special biological treatment facilities. In the first case, domestic sewage is supplied to irrigation fields. Here, wastewater is filtered through the soil and at the same time undergoes bacterial treatment. Irrigated fields accumulate a huge amount of organic fertilizers, which makes it possible to grow high yields on them. complex system The biological treatment of polluted Rhine waters for the purposes of water supply for a number of cities in the country was developed and used by the Dutch. Pumping stations with partial filters have been built on the Rhine. From the river, water is pumped into shallow ditches onto the surface of the river terraces. Through the thickness of almovial deposits, it is filtered, replenishing groundwater. Groundwater is supplied through wells for additional treatment and then enters the water supply system. Treatment facilities solve the problem of maintaining the quality of fresh water only up to a certain stage in the development of the economy of specific geographical regions. Then there comes a point when local water resources are no longer enough to dilute the increased amount of treated wastewater. Then the progressive pollution of water resources begins, and their qualitative depletion begins. In addition, at all treatment plants, as effluents increase, the problem arises of accommodating significant volumes of filtered pollutants. Thus, the treatment of industrial and municipal wastewater provides only a temporary solution to local problems of protecting water from pollution. The cardinal ways of protection against pollution and destruction of natural aquatic and associated natural territorial complexes is to reduce or even complete cessation discharge of waste water, including treated waste water, into water bodies. Improvement of technological processes gradually solves these problems. An increasing number of enterprises use a closed water supply cycle. In this case, the waste water undergoes only partial treatment, after which they can be used again in a number of industries. Full implementation of all measures aimed at stopping sewage discharges into rivers, lakes and reservoirs is possible only under the conditions of the existing territorial production complexes. Within industrial complexes, complex technological links between various enterprises can be used to organize a closed water supply cycle.

In the future, treatment facilities will not discharge waste water into water bodies, but will become one of the technological links in the closed water supply chain. The progress of technology, careful consideration of local hydrological, physical and economic-geographical conditions in the planning and formation of territorial production complexes make it possible in the future to ensure the quantitative and qualitative preservation of all links in the fresh water cycle, to turn fresh water resources into inexhaustible ones. Increasingly, other parts of the hydrosphere are used to replenish freshwater resources. Thus, a fairly effective technology for seawater desalination has been developed. Technically, the problem of seawater desalination has been solved. However, this requires a lot of energy, and therefore desalinated water is still very expensive. It is much cheaper to desalinate brackish groundwater. With the help of solar plants, these waters are desalinated in the south of the United States, on the territory of Kalmykia, Krasnodar Territory, Volgograd region. At international conferences on the problems of water resources, the possibilities of transferring fresh water preserved in the form of icebergs are being discussed.

For the first time, the American geographer and engineer John Isaacs suggested using icebergs to supply water to arid regions of the globe. According to his project, icebergs should be transported by ships from the coast of Antarctica to the cold Peruvian current and further along the system of currents to the coast of California. Here they are attached to the shore, and the fresh water formed during the melting will be piped to the mainland. Moreover, due to condensation on the cold surface of icebergs, the amount of fresh water will be 25% greater than that contained in them themselves. Vladimirov A.M. etc. Environmental protection. St. Petersburg: Gidrometeoizdat 1991. -158s.

Conclusion

Along with the moral problem, there is another not unimportant problem - the relationship of man to nature. The life of man and nature are closely interconnected and it is not surprising that many authors in their works reveal this problem.

The protection of nature is the task of our century, a problem that has become a social one. Again and again we hear about the danger threatening the environment, but still many of us consider them an unpleasant, but inevitable product of civilization and believe that we will still have time to cope with all the difficulties that have come to light.

However, human impact on the environment has taken on alarming proportions. To fundamentally improve the situation, purposeful and thoughtful actions will be needed. A responsible and efficient environmental policy will be possible only if we accumulate reliable data on the current state of the environment, sound knowledge of the interaction of important environmental factors, if he develops new methods to reduce and prevent the harm caused to Nature by Man.

In my opinion, there are still people on our planet who value and love nature, who are trying with all their might to prevent an ecological catastrophe. It's great that Greenpeace exists. But not everyone has yet realized the seriousness of this problem. In my opinion, in our country, and throughout the world, there should be more writers and poets who, in their work, shout to the whole world about the problem that threatens our planet, about a truly human attitude to nature. I believe that you can not just take without giving anything in return. And let the writers' appeals touch the soul of every person on Earth.

Bibliography

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