Message about the problem of clean natural water. Clean Water Problems
Among the chemical compounds that a person has to deal with in his Everyday life, water, perhaps, is the most familiar and at the same time the strangest. Its amazing properties have always attracted the attention of scientists, and in last years In addition, they became an occasion for various near-scientific speculations. Water is not a passive solvent, as is commonly believed, it is an active actor in molecular biology; when it freezes, it expands rather than shrinking like most liquids, reaching its highest density at 4°C. So far, none of the theorists working on general theory liquids, did not come close to describing its strange properties.
Special mention deserves weak hydrogen bonds, due to which water molecules form on a short time quite complex structures. A 2004 Science article by Lars Pettersson and his colleagues at Stockholm University made a lot of noise. In it, in particular, it was stated that each water molecule is connected by hydrogen bonds with exactly two others. Because of this, chains and rings arise, with a length of the order of hundreds of molecules. It is along this path that researchers hope to find a rational explanation for the strangeness of water.
But for the inhabitants of our planet, water is primarily interesting not for this: without clean drinking water, they will all simply die out, and its availability becomes more and more problematic over the years. According to the World Health Organization (WHO), currently 1.2 billion people do not have it in the required amount, millions of people die every year from diseases caused by substances dissolved in water. In January 2008, at the UN World Economic Forum Annual Meeting 2008, held in Switzerland, it was argued that by 2025 the population of more than half of the world's countries will lack clean water, and by 2050 - 75%.
The problem of clean water is coming from all sides: for example, scientists suggest that in the next 30 years, the melting of glaciers (one of the main fresh water reserves on Earth) will lead to strong jumps in the level of many major rivers, such as the Brahmaputra, the Ganges, the Yellow River, which will put one and a half billion people in Southeast Asia at risk of lack of drinking water. At the same time, even now the flow of water, for example, from the Yellow River is so great that it periodically does not reach the sea.
Reduction of fresh water reserves
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 3 per year. 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, half of which is due to the transpiration of moisture by plants. Every year, a layer of water about 1250 mm thick evaporates. 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. The natural distiller feeds on the energy of the Sun and takes away 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. Fresh waters of the rivers have the greatest practical value for mankind.
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 perfect cleaning, including biological, all dissolved inorganic substances and up to 10% of organic pollutants remain in treated wastewater. Such water can again become suitable for consumption only after repeated dilution with pure 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 3 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 3 of treated waste water "spoils" 10 km 3 of river water, and not purified - 3-5 times more. The amount of fresh water does not decrease, but its quality drops sharply, it becomes unsuitable for consumption.
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 closed 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.
The total runoff of the rivers of the CIS (USSR) for the year is 4720 km. But water resources are distributed extremely unevenly. In the most populated regions, where up to 80% of industrial production lives and 90% of land suitable for agriculture is located, the share of water resources is only 20%. Many parts of the country are not sufficiently supplied with water. This is the south and southeast of the European part of the CIS, the Caspian lowland, south Western Siberia and Kazakhstan, and some other areas Central Asia, south of Transbaikalia, Central Yakutia. The northern regions of the CIS, the Baltic states, the mountainous regions of the Caucasus, Central Asia, the Sayan and Far East.
The flow of rivers varies depending on climate fluctuations. Human intervention in natural processes has already affected river runoff. AT agriculture most of water does not return to the rivers, but is spent on evaporation and the formation of plant mass, since during photosynthesis hydrogen from water molecules passes into organic compounds. To regulate the flow of rivers, which is not uniform throughout the year, 1,500 reservoirs have been built (they regulate up to 9% of the total flow). The runoff of the rivers of the Far East, Siberia and the North of the European part of the country has not yet been affected by human economic activity. However, in the most populated areas, it decreased by 8%, and near such rivers as the Terek, Don, Dniester and Ural by 11-20%. The water runoff in the Volga, Syr Darya and Amu Darya has noticeably decreased. As a result, the inflow of water to the Sea of Azov decreased by 23%, to the Aral Sea - by 33%. The level of the Aral fell by 12.5 m.
Limited and even scarce in many countries, fresh water supplies are being significantly reduced due to pollution. Usually, pollutants are divided into several classes depending on their nature, chemical structure and origin.
Water pollution from domestic, agricultural and industrial waste.
Organic materials come from domestic, agricultural or industrial effluents. Their decomposition occurs under the action of microorganisms and is accompanied by the consumption of oxygen dissolved in water. If there is enough oxygen in the water and the amount of waste is small, then aerobic bacteria quickly turn them into relatively harmless residues. Otherwise, the activity of aerobic bacteria is suppressed, the oxygen content drops sharply, and decay processes develop. When the oxygen content in water is below 5 mg per 1 liter, and in spawning areas - below 7 mg, many fish species die.
Pathogens and viruses are found in poorly treated or completely untreated sewage from settlements and livestock farms. Once in drinking water, pathogenic microbes and viruses cause various epidemics, such as outbreaks of salmonellosis, gastroenteritis, hepatitis, etc. In developed countries, the spread of epidemics through public water supply is rare at present. Food products can be contaminated, such as vegetables grown in fields that are fertilized with sludge from domestic wastewater treatment (from German Schlamme - literally dirt). Aquatic invertebrates, such as oysters or other mollusks, from contaminated water bodies have often been the cause of outbreaks of typhoid fever.
Nutrients, mainly nitrogen and phosphorus compounds, enter water bodies with domestic and agricultural sewage. An increase in the content of nitrites and nitrates in surface and groundwater leads to contamination of drinking water and the development of certain diseases, and the growth of these substances in water bodies causes their increased eutrophication (an increase in the reserves of nutrients and organic substances, which is why plankton and algae are rapidly developing, absorbing all the oxygen in the water).
Inorganic and organic substances also include heavy metal compounds, petroleum products, pesticides (toxic chemicals), synthetic detergents (detergents), phenols. They enter water bodies with industrial waste, domestic and agricultural wastewater. Many of them in the aquatic environment either do not decompose at all, or decompose very slowly and can accumulate in food chains.
The increase in bottom sediments is one of the hydrological consequences of urbanization. Their number in rivers and reservoirs is constantly increasing due to soil erosion as a result of improper agriculture, deforestation, and regulation of river flow. This phenomenon leads to a violation of the ecological balance in aquatic systems, and benthic organisms have a detrimental effect.
Thermal water pollution
The source of thermal pollution is the heated wastewater from thermal power plants and industry. An increase in the temperature of natural waters changes natural conditions for aquatic organisms, reduces the amount of dissolved oxygen, changes the metabolic rate. Many inhabitants of rivers, lakes or reservoirs perish, the development of others is suppressed.
A few decades ago, polluted waters were like islands in a relatively clean natural environment. Now the picture has changed, solid arrays of contaminated territories have formed.
Oil pollution of the oceans
Oil pollution of the oceans is undoubtedly the most widespread phenomenon. From 2 to 4% of the water surface of the Pacific and Atlantic Oceans permanently covered with an oil film. Up to 6 million tons of oil hydrocarbons enter sea waters annually. Almost half of this amount is associated with the transportation and development of deposits on the shelf. Continental oil pollution enters the ocean through river runoff.
The rivers of the world annually carry out more than 1.8 million tons of oil products into the sea and ocean waters.
At sea, oil pollution takes many forms. It can cover the surface of the water with a thin film, and in case of spills, the thickness of the oil coating can initially be several centimeters. Over time, an oil-in-water or water-in-oil emulsion is formed. Later, there are lumps of heavy fraction of oil, oil aggregates that are able to float on the surface of the sea for a long time. Various small animals are attached to floating lumps of fuel oil, which fish and baleen whales willingly feed on. Together with them, they swallow oil. Some fish die from this, others are soaked through with oil and become unsuitable for eating due to an unpleasant smell and taste.
All oil components are toxic to marine organisms. Oil affects the structure of the marine animal community. With oil pollution, the ratio of species changes and their diversity decreases. So, microorganisms that feed on petroleum hydrocarbons develop abundantly, and the biomass of these microorganisms is poisonous to many marine life. It has been proven that long-term chronic exposure to even small concentrations of oil is very dangerous. At the same time, the primary biological productivity of the sea is gradually decreasing. Oil has another unpleasant side property. Its hydrocarbons are capable of dissolving a number of other pollutants, such as pesticides, heavy metals, which, together with oil, are concentrated in the near-surface layer and poison it even more. The aromatic fraction of oil contains substances of a mutagenic and carcinogenic nature, such as benzapyrene. Much evidence has now been obtained for the mutagenic effects of polluted marine environments. Benzopyrene circulates extensively in marine food chains and ends up in human food.
The largest amounts of oil are concentrated in a thin surface layer of sea water, which plays a particularly important role for various aspects of ocean life. Many organisms are concentrated in it, this layer plays a role " kindergarten"for many populations. Surface oil films disrupt gas exchange between the atmosphere and the ocean. The processes of dissolution and release of oxygen, carbon dioxide, heat transfer undergo changes, the reflectivity (albedo) of sea water changes.
I suffer most from poultry oil, especially when coastal waters are polluted. Oil glues plumage, it loses its heat-insulating properties, and, in addition, a bird stained with oil cannot swim. Birds freeze and drown. Even cleaning feathers with solvents does not save all the victims. The rest of the inhabitants of the sea suffer less. Numerous studies have shown that oil that has entered the sea does not create any permanent or long-term danger to organisms living in the water and does not accumulate in them, so that its entry into humans through the food chain is excluded.
According to the latest data, significant damage to flora and fauna can be inflicted only in individual cases. For example, oil products made from it - gasoline, diesel fuel, and so on - are much more dangerous than crude oil. Dangerous are high concentrations of oil in the littoral (tidal zone), especially on a sandy shore, in these cases the concentration of oil remains high for a long time, and it causes a lot of harm. But fortunately such cases are rare.
Usually, during tanker accidents, oil quickly disperses through the water, dilutes, and begins to decompose. It has been shown that oil hydrocarbons can pass without harm to marine organisms through their digestive tract and even through tissues: such experiments were carried out with crabs, bivalves, different types small fish, and no harmful effects were found in experimental animals.
Other pollution water resources
Chlorinated hydrocarbons, widely used as a means of combating pests in agriculture and forestry, with carriers of infectious diseases, have been entering the World Ocean along with river runoff and through the atmosphere for many decades. DDT and its derivatives, polychlorinated biphenyls and other stable compounds of this class are now found throughout the world's oceans, including the Arctic and Antarctic. They are easily soluble in fats and therefore accumulate in the organs of fish, mammals, seabirds. Being xenobiotics, i.e., substances of completely artificial origin, they do not have their "consumers" among microorganisms and therefore almost do not decompose into natural conditions, but only accumulate in the oceans. At the same time, they are acutely toxic, affect the hematopoietic system, inhibit enzymatic activity, and strongly affect heredity.
Along with river runoff, heavy metals also enter the ocean, many of which have toxic properties. The total river runoff is 46 thousand km of water per year. Together with it, up to 2 million tons of lead, up to 20 thousand tons of cadmium and up to 10 thousand tons of mercury enter the World Ocean. Most high levels pollution have coastal waters and inland seas. The atmosphere also plays a significant role in the pollution of the oceans. For example, up to 30% of all mercury and 50% of lead entering the ocean annually is transported through the atmosphere. Due to its toxic effect in the marine environment, mercury is of particular danger. Under the influence of microbiological processes, toxic inorganic mercury is converted into much more toxic organic forms of mercury. Methylmercury compounds accumulated through bioaccumulation in fish or shellfish pose a direct threat to human life and health. Let us recall, for example, the infamous Minamato disease, which got its name from the Gulf of Japan, where poisoning was so sharply manifested. local residents mercury. It claimed many lives and undermined the health of many people who ate seafood from this bay, at the bottom of which a lot of mercury accumulated from waste from a nearby plant.
Mercury, cadmium, lead, copper, zinc, chromium, arsenic and other heavy metals not only accumulate in marine organisms, thereby poisoning marine food, but also most detrimentally affect the inhabitants of the sea. Accumulation ratios toxic metals, i.e., their concentration per unit weight in marine organisms in relation to sea water, vary widely - from hundreds to hundreds of thousands, depending on the nature of metals and types of organisms. These coefficients show how harmful substances accumulate in fish, molluscs, crustaceans, plankton and other organisms. The scale of pollution of products of the seas and oceans is so great that in many countries sanitary standards have been established for the content of certain harmful substances in them. It is interesting to note that at only 10 times the natural mercury concentration in the water, oyster contamination already exceeds the limits set in some countries. This shows how close the limit of sea pollution is, which cannot be crossed without harmful consequences for human life and health.
There is still plenty of water on the planet, but the proportion of drinkable water is rapidly declining.
In five years, clean water will be more expensive than oil and gas. Already today, 1 billion 400 million people in the world do not have access to clean quality water. In the process of anthropogenic influences, water sources in many states are polluted with heavy metals, pesticides, herbicides, dioxides, pathogenic microflora and have lost the ability to self-purify.
That is why clean drinking water can be found not so often. And over the years, the problem will only get worse. According to the UN report, the number of territories with a shortage of drinking water will more than double.
But high-quality and safe drinking water is not only the most important factor in the quality of life of the population, but also the leading factor affecting people's health.
Russia is in the top ten of the world in terms of fresh water reserves. It is Russia that has 22% of the world's supply of life-giving moisture. At the same time, one of the most pressing problems in the country is poor-quality drinking water, which is caused, in particular, by the extreme deterioration of water distribution networks in settlements. In addition, 90% of wastewater discharges in Russia are not treated until right level, and approximately 60% of this amount is “provided” by housing and communal services (HCS).
The issue of clean water is directly related to the demographic problem, which is not only an increase in the birth rate, but also a decrease in mortality, an increase in the life expectancy of Russians.
Due to the use of poor-quality drinking water, such dangerous diseases as dysentery, typhoid, hepatitis, meningitis. You can get sick through water jaundice, tularemia, water fever, brucellosis, poliomyelitis. According to the World Health Organization (WHO), 80% of all diseases are caused by the use of poor-quality drinking water.
There are regions in Russia where up to half of all diseases are associated with the use of poor-quality water. The cost of risk and loss of public health from the consumption of poor-quality drinking water in Russia as a whole is estimated at about 33.7 billion rubles a year.
This is also connected with the country's lag behind other industrialized countries in terms of average life expectancy of the population. According to experts, only improving the quality of drinking water will increase the average life expectancy by 5-7 years.
The party project of "United Russia" - "Clean Water" has set as its goal fundamental changes in the field of water supply services. And I fully agree with the words of the head of our faction, B. V. Gryzlov, that “the implementation of this project has great value to maintain health, improve working conditions and improve the quality of life of Russians. Today, all conditions have been created for this party project to be transformed into a state program, which can begin its operation as early as 2010.
The draft state program "Clean Water" has been repeatedly submitted for discussion in the framework of joint meetings with representatives of ministries and departments. It is planned that the program (already finalized taking into account the comments of the Government) will be submitted on October 1 this year.
By this time, three technical regulations (on the quality of drinking water from the pipeline, wastewater and bottled water), which are being prepared by deputies of the State Duma, should also be adopted by this time.
One of the main tasks of the Clean Water project is to streamline and improve the regulatory framework in the field of drinking water supply. In this regard, the special technical regulation "On drinking water and drinking water supply" and the general technical regulation "On water disposal" were included in the list of priority bills of the United Russia faction.
Currently, the norms of the existing legislation on drinking water are very contradictory, vague and scattered across various documents. A whole set of articles is completely outdated and does not correspond to existing realities. But even ideal legislative norms will not be able to change the situation in the field of water supply without technical re-equipment. As long as the water enters the houses after the "journey" through rusty pipes, there is no high quality and cleanliness does not have to speak.
To date, about 15?% of drinking water is completely unfit for consumption, and only 12% of tap water meets generally accepted criteria. These figures clearly demonstrate the importance of adopting legislation in the field of drinking water supply and organization of drinking water supply.
Obviously, water must meet all sanitary and epidemiological characteristics, not only at the point of intake, but also at the exit from the tap. Otherwise, all attempts to clean it up are in vain. At the same time, not every Russian region, for economic reasons, can afford modern engineering communications.
In a situation where there are donors and subsidized subjects of the Federation in the country, one cannot shift all responsibility only to local authorities. Without federal funding economic disparities, in particular in the field of renewing drinking water communications, cannot be overcome. Therefore, it is vital to create a federal target program "Clean Water" for the period up to 2020.
Implementation of such federal program will not only have a positive impact on the health of Russians, but may also have quite tangible economic benefits, as it will allow further consideration of the issue of Russia's export of clean water. A separate project could be the supply of water to the African continent, where, in fact, there are no pure sources of life-giving moisture, since all available resources are characterized by a high concentration of arsenic. The supply of water to Africa using the tanker fleet is a specific economic project, which was announced by the Chairman of the State Duma of the Federal Assembly of the Russian Federation B. V. Gryzlov. So the water industry in Russia may well become a successful economic project, part of the revenue items of the federal budget
Water pollution from domestic, agricultural and industrial waste. Environmental consequences oil releases into the oceans. Salt water desalination technologies. Application of membrane bioreactors for wastewater reuse.
INTRODUCTION
1. The essence of the clean water problem
1.1 Reduction of fresh water resources
1.2 Water pollution from domestic, agricultural and industrial effluents
1.3 Thermal water pollution
1.4 Oil pollution of the oceans
1.5 Other water pollution
2. Possible solutions
2.1 Water purification
2.2 Water recycling
2.3 Salt water desalination
Conclusion
List of sources used
Application
INTRODUCTION
It can perhaps be said that
the purpose of a person
is to
destroy your family
pre-made globe
unsuitable for habitation.
J.-B. Lamarck
Once people were content with water, which they found in rivers, lakes, streams and wells. But with the development of industry and the growth of the population, it became necessary to manage the water supply much more carefully in order to avoid harm to human health and damage to the environment.
Before inexhaustible resource- fresh clean water - to become depleted. Today, drinking water industrial production and irrigation is lacking in many parts of the world. Even now, 20,000 people die every year due to dioxin pollution of water bodies in Russia.
The topic I have chosen is more relevant today than ever, because if not we, then our children will definitely feel the full impact of anthropogenic environmental pollution. At the same time, if you recognize the problem in time and follow the ways to solve it, then an ecological catastrophe can be avoided.
The purpose of this work is to get acquainted with the problem of clean water as a global environmental problem. Significant attention will be paid to the causes, environmental consequences and possible solutions to this problem.
1. The essence of the clean water problem
Among the chemical compounds that a person has to deal with in his daily life, water is perhaps the most familiar and at the same time the most strange. Its amazing properties have always attracted the attention of scientists, and in recent years have become, in addition, a pretext for various near-scientific speculations. Water is not a passive solvent, as is commonly believed, it is an active agent in molecular biology; when it freezes, it expands rather than shrinking like most liquids, reaching its highest density at 4°C. So far, none of the theorists working on the general theory of fluids has come close to describing its strange properties.
Weak hydrogen bonds deserve special mention, thanks to which water molecules form rather complex structures for a short time. A 2004 Science article by Lars Pettersson and his colleagues at Stockholm University made a lot of noise. In it, in particular, it was stated that each water molecule is connected by hydrogen bonds with exactly two others. Because of this, chains and rings arise, with a length of the order of hundreds of molecules. It is along this path that researchers hope to find a rational explanation for the strangeness of water.
But for the inhabitants of our planet, water is not primarily interesting for this: without clean drinking water, they will all simply die out, and its availability becomes more and more problematic over the years. According to the World Health Organization (WHO), today 1.2 billion people do not have it in the required amount, millions of people die every year from diseases caused by substances dissolved in water. In January 2008, at the UN World Economic Forum Annual Meeting 2008, held in Switzerland, it was argued that by 2025 the population of more than half of the world's countries will lack clean water, and by 2050 - 75%.
The problem of clean water is coming from all sides: for example, scientists suggest that in the next 30 years, the melting of glaciers (one of the main fresh water reserves on Earth) will lead to strong jumps in the level of many large rivers, such as the Brahmaputra, Ganges, Huang He, which will put one and a half billion people in Southeast Asia are at risk of lack of drinking water. At the same time, even now the flow of water, for example, from the Yellow River is so great that it periodically does not reach the sea.
1.1 Reduction of fresh waterwaters
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 3 per year. 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, half of which is due to the transpiration of moisture by plants. Every year, a layer of water about 1250 mm thick evaporates. 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. The natural distiller feeds on the energy of the Sun and takes away 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. Fresh waters of the rivers have the greatest practical value for mankind.
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 with pure 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 3 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 3 of treated waste water "spoils" 10 km 3 of river water, and not purified - 3-5 times more. The amount of fresh water does not decrease, but its quality drops sharply, it becomes unsuitable for consumption.
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 closed 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. At the same time, in any part of the world, they can be depleted due to irrational 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 consume almost 70% of all water used in industry (see appendix). 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.
The total runoff of the rivers of the CIS (USSR) for the year is 4720 km. But water resources are distributed extremely unevenly. In the most populated regions, where up to 80% of industrial production lives and 90% of land suitable for agriculture is located, the share of water resources is only 20%. Many parts of the country are not sufficiently supplied with water. These are the south and southeast of the European part of the CIS, the Caspian lowland, the south of Western Siberia and Kazakhstan, and some other regions of Central Asia, the south of Transbaikalia, Central Yakutia. The northern regions of the CIS, the Baltic states, the mountainous regions of the Caucasus, Central Asia, the Sayan Mountains and the Far East are best provided with water.
The flow of rivers varies depending on climate fluctuations. Human intervention in natural processes has already affected river runoff. In agriculture, most of the water is not returned to the rivers, but is spent on evaporation and the formation of plant mass, since during photosynthesis, hydrogen from water molecules is converted into organic compounds. To regulate the flow of rivers, which is not uniform throughout the year, 1,500 reservoirs have been built (they regulate up to 9% of the total flow). The runoff of the rivers of the Far East, Siberia and the North of the European part of the country has not yet been affected by human economic activity. At the same time, in the most populated areas, it decreased by 8%, and near such rivers as the Terek, Don, Dniester and Ural by 11-20%. The water runoff in the Volga, Syr Darya and Amu Darya has noticeably decreased. As a result, the inflow of water to the Sea of Azov decreased by 23%, to the Aral Sea - by 33%. The level of the Aral fell by 12.5 m.
Limited and even scarce in many countries, fresh water supplies are being significantly reduced due to pollution. Usually pollutants are divided into several classes depending on their nature, chemical structure and origin.
1.2 household water pollutionovymi, agricultural andindustrial waste.
Organic materials come from domestic, agricultural or industrial effluents. Their decomposition occurs under the action of microorganisms and is accompanied by the consumption of oxygen dissolved in water. If there is enough oxygen in the water and the amount of waste is small, then aerobic bacteria quickly turn them into relatively harmless residues. Otherwise, the activity of aerobic bacteria is suppressed, the oxygen content drops sharply, and decay processes develop. When the oxygen content in water is below 5 mg per 1 liter, and in spawning areas - below 7 mg, many fish species die.
Pathogens and viruses are found in poorly treated or completely untreated sewage from settlements and livestock farms. Once in drinking water, pathogenic microbes and viruses cause various epidemics, such as outbreaks of salmonellosis, gastroenteritis, hepatitis, etc. In developed countries, the spread of epidemics through public water supply is rare today. Food products may be contaminated, such as vegetables grown in fields that are fertilized with sludge from domestic wastewater treatment (from German Schlamme - literally dirt). Aquatic invertebrates, such as oysters or other mollusks, from contaminated water bodies have often been the cause of outbreaks of typhoid fever.
Nutrients, mainly nitrogen and phosphorus compounds, enter water bodies with domestic and agricultural wastewater. An increase in the content of nitrites and nitrates in surface and ground waters leads to contamination of drinking water and the development of certain diseases, and the growth of these substances in water bodies causes their increased eutrophication (an increase in the reserves of nutrients and organic matter, which causes plankton and algae to flourish, absorbing all the oxygen in the water).
Inorganic and organic substances also include heavy metal compounds, petroleum products, pesticides (toxic chemicals), synthetic detergents (detergents), phenols. They enter water bodies with industrial waste, domestic and agricultural wastewater. Many of them in the aquatic environment either do not decompose at all, or decompose very slowly and can accumulate in food chains.
The increase in bottom sediments is one of the hydrological consequences of urbanization. Their number in rivers and reservoirs is constantly increasing due to soil erosion as a result of improper agriculture, deforestation, and regulation of river flow. This phenomenon leads to a violation of the ecological balance in aquatic systems, and benthic organisms have a detrimental effect.
1.3 Thermal water pollution
The source of thermal pollution is the heated wastewater from thermal power plants and industry. An increase in the temperature of natural waters changes the natural conditions for aquatic organisms, reduces the amount of dissolved oxygen, and changes the metabolic rate. Many inhabitants of rivers, lakes or reservoirs perish, the development of others is suppressed.
A few decades ago, polluted waters were like islands in a relatively clean natural environment. Now the picture has changed, solid arrays of contaminated territories have formed.
1.4 oil pollutionWorldocean
Oil pollution of the oceans is undoubtedly the most widespread phenomenon. From 2 to 4% of the water surface of the Pacific and Atlantic oceans is constantly covered with an oil slick. Up to 6 million tons of oil hydrocarbons enter sea waters annually. Almost half of this amount is associated with the transportation and development of deposits on the shelf. Continental oil pollution enters the ocean through river runoff.
The rivers of the world annually carry out more than 1.8 million tons of oil products into the sea and ocean waters.
At sea, oil pollution takes many forms. It can cover the surface of the water with a thin film, and in case of spills, the thickness of the oil coating can initially be several centimeters. Over time, an oil-in-water or water-in-oil emulsion is formed. Later, there are lumps of heavy fraction of oil, oil aggregates that are able to float on the surface of the sea for a long time. Various small animals are attached to floating lumps of fuel oil, which fish and baleen whales willingly feed on. Together with them, they swallow oil. Some fish die from this, others are soaked through with oil and become unsuitable for eating due to an unpleasant smell and taste. .
All oil components are toxic to marine organisms. Oil affects the structure of the marine animal community. With oil pollution, the ratio of species changes and their diversity decreases. So, microorganisms that feed on petroleum hydrocarbons develop abundantly, and the biomass of these microorganisms is poisonous to many marine life. It has been proven that long-term chronic exposure to even small concentrations of oil is very dangerous. At the same time, the primary biological productivity of the sea is gradually decreasing. Oil has another unpleasant side property. Its hydrocarbons are capable of dissolving a number of other pollutants, such as pesticides, heavy metals, which, together with oil, are concentrated in the near-surface layer and poison it even more. The aromatic fraction of oil contains substances of a mutagenic and carcinogenic nature, such as benzpyrene. Much evidence has now been obtained for the mutagenic effects of polluted marine environments. Benzpyrene actively circulates through the marine food chains and ends up in human food.
The largest amounts of oil are concentrated in a thin near-surface layer of sea water, which plays a particularly important role for various aspects of ocean life. Many organisms are concentrated in it, this layer plays the role of a "kindergarten" for many populations. Surface oil films disrupt gas exchange between the atmosphere and the ocean. The processes of dissolution and release of oxygen, carbon dioxide, heat transfer undergo changes, the reflectivity (albedo) of sea water changes.
I suffer most from poultry oil, especially when coastal waters are polluted. Oil glues plumage, it loses its heat-insulating properties, and, in addition, a bird stained with oil cannot swim. Birds freeze and drown. Even cleaning feathers with solvents does not save all the victims. The rest of the inhabitants of the sea suffer less. Numerous studies have shown that oil that has entered the sea does not create any permanent or long-term danger to organisms living in the water and does not accumulate in them, so that its entry into humans through the food chain is excluded.
According to the latest data, significant damage to flora and fauna can be inflicted only in individual cases. For example, oil products made from it - gasoline, diesel fuel, and so on - are much more dangerous than crude oil. Dangerous are high concentrations of oil in the littoral (tidal zone), especially on a sandy shore, in these cases the concentration of oil remains high for a long time, and it causes a lot of harm. But fortunately such cases are rare.
Usually, during tanker accidents, oil quickly disperses through the water, dilutes, and begins to decompose. It has been shown that oil hydrocarbons can pass through their digestive tract and even through tissues without harm to marine organisms: such experiments were carried out with crabs, bivalves, various types of small fish, and no harmful effects were found for experimental animals.
1.5 Other water pollution
Chlorinated hydrocarbons, widely used as a means of combating pests in agriculture and forestry, with carriers of infectious diseases, have been entering the World Ocean along with river runoff and through the atmosphere for many decades. DDT and its derivatives, polychlorinated biphenyls and other stable compounds of this class are now found throughout the world's oceans, including the Arctic and Antarctic. They are easily soluble in fats and therefore accumulate in the organs of fish, mammals, seabirds. Being xenobiotics, i.e., substances of completely artificial origin, they do not have their "consumers" among microorganisms and therefore almost do not decompose in natural conditions, but only accumulate in the World Ocean. At the same time, they are acutely toxic, affect the hematopoietic system, inhibit enzymatic activity, and strongly affect heredity.
Along with river runoff, heavy metals also enter the ocean, many of which have toxic properties. The total river runoff is 46 thousand km of water per year. Together with it, up to 2 million tons of lead, up to 20 thousand tons of cadmium and up to 10 thousand tons of mercury enter the World Ocean. Coastal waters and inland seas have the highest pollution levels. The atmosphere also plays a significant role in the pollution of the oceans. For example, up to 30% of all mercury and 50% of lead entering the ocean annually is transported through the atmosphere. Due to its toxic effect in the marine environment, mercury is of particular danger. Under the influence of microbiological processes, toxic inorganic mercury is converted into much more toxic organic forms of mercury. Methylmercury compounds accumulated through bioaccumulation in fish or shellfish pose a direct threat to human life and health. Let us recall, for example, the infamous "minamato" disease, which got its name from the Gulf of Japan, where the poisoning of local residents with mercury was so sharply manifested. It claimed many lives and undermined the health of many people who ate seafood from this bay, at the bottom of which a lot of mercury accumulated from waste from a nearby plant. Mercury, cadmium, lead, copper, zinc, chromium, arsenic and other heavy metals not only accumulate in marine organisms, thereby poisoning marine food, but also most detrimentally affect the inhabitants of the sea. The accumulation coefficients of toxic metals, i.e., their concentration per unit weight in marine organisms in relation to sea water, vary widely - from hundreds to hundreds of thousands, depending on the nature of the metals and the types of organisms. These coefficients show how harmful substances accumulate in fish, molluscs, crustaceans, plankton and other organisms. The scale of pollution of products of the seas and oceans is so great that in many countries sanitary standards have been established for the content of certain harmful substances in them. It is interesting to note that at only 10 times the natural mercury concentration in the water, oyster contamination already exceeds the limits set in some countries. This shows how close the limit of sea pollution is, which cannot be crossed without harmful consequences for human life and health.
2. Possible solutions
In order to avoid a water crisis, new technologies are being developed for water purification and disinfection, its desalination, as well as methods for its reuse. At the same time, in addition to scientific research, it is necessary to effective methods organization of control over the water resources of countries: unfortunately, in most states, several organizations are involved in the use and planning of water resources (for example, in the USA more than twenty different federal agencies are involved in this). This topic became the theme for the March 19, 2007 issue of the scientific journal Nature. In particular, Mark Shannon and his colleagues from the University of Illinois at Urbana-Champaign (USA) reviewed new scientific developments and next generation systems in the following areas: water disinfection and pathogen removal without the use of excessive amounts of chemicals and the formation of toxic by-products; detection and removal of pollutants in low concentration; reuse of water, as well as desalination of sea and inland waters. Importantly, these technologies should be relatively inexpensive and suitable for use in developing countries.
2.1 Water purification
Disinfection is especially important in the developing countries of Southeast Asia and the Sub-Saharan Africa, where waterborne pathogens are most likely to cause mass disease. Along with pathogens - such as helminths (worms), unicellular protozoa, fungi and bacteria, viruses and prions pose an increased danger. Free chlorine - the world's most common (and also the cheapest and one of the most effective) disinfectant - does an excellent job with intestinal viruses, but is powerless against diarrhea-causing Cryptosporidium C. parvum or mycobacteria. The situation is complicated by the fact that many pathogens live in thin biofilms on the walls of water pipes.
New effective methods of disinfection should consist of several barriers: removal with physical and chemical reactions(eg coagulation, sedimentation or membrane filtration) and neutralization with ultraviolet light and chemicals. Relatively recently, visible light has again been used for photochemical neutralization of pathogens, and in some cases, the combination of UV with chlorine or ozone is effective. True, this approach sometimes causes the appearance of harmful by-products: for example, the action of ozone in water containing bromide ions can cause the carcinogen bromate.
In India, where the need for water disinfection is felt quite acutely, sap water is used for this purpose.
In developing countries, polyethylene terephthalate (PET) bottled water disinfection technology is used by, firstly, sunlight, secondly, sodium hypochlorite (this method is used mainly in rural areas). Thanks to chlorine, it was possible to reduce the incidence of gastrointestinal diseases, however, in areas where ammonia and organic nitrogen are contained in the water, the method does not work: chlorine forms compounds with these substances and becomes inactive.
It is assumed that in the future disinfection methods will include the action of ultraviolet and nanostructures. Ultraviolet radiation is effective in the fight against bacteria living in water, with protozoan cysts, but does not act on viruses. However, ultraviolet light can activate photocatalyst compounds such as titanium (TiO2), which in turn can kill viruses. In addition, new compounds, such as TiO2 with nitrogen (TiON) or with nitrogen and some metals (palladium), can be activated by visible light, which requires less energy than ultraviolet irradiation, or even just sunlight. True, such installations for disinfection have an extremely low productivity.
Another important task in water purification is the removal of harmful substances from it. There is a huge amount of toxic substances and compounds (such as arsenic, heavy metals, halogenated aromatic compounds, nitrosamines, nitrates, phosphates, and many others). The list of substances supposedly harmful to health is constantly growing, and many of them are toxic even in trace amounts. It is difficult and expensive to detect these substances in water and then remove them in the presence of other, non-toxic impurities, the content of which can be an order of magnitude higher. And above all, this search for one toxin can interfere with the detection of another, more dangerous one. Methods for monitoring pollutants inevitably involve the use of sophisticated laboratory equipment and the involvement of qualified personnel, so it is very important to find inexpensive and relatively simple ways pollution identification.
A kind of "specialization" is also important here: for example, arsenic trioxide (As-III) is 50 times more toxic than pentoxide (As-V), and therefore it is necessary to measure their content both together and separately, for subsequent neutralization or removal. Existing measurement methods either have a low accuracy limit or require qualified specialists.
Scientists believe that promising direction in the development of methods for detecting harmful substances is the method of molecular recognition (molecular recognition motif), based on the use of sensory reagents (like litmus paper familiar from school), together with micro- or nanofluidic control (micro / nanofluidic manipulation) and telemetry. Similar biosensor methods can be applied to pathogens living in water. At the same time, in this case, it is necessary to monitor the presence of anions in the water: their presence can neutralize quite effective - under other conditions - methods. So, when water is treated with ozone, bacteria die, but if there are Br- ions in the water, oxidation to BrO3- occurs, that is, one type of pollution changes to another.
water on the opposite side. In accordance with the laws of hydrostatics, water seeps through the membrane, clearing up the road. In general, there are two ways to deal with harmful substances-- influencing the micro-pollutant with chemical or biochemical reagents until it changes into a non-hazardous form, or removing it from the water. This issue is decided depending on the area. For example, wells in Bangladesh use Sono filtration technology, and factories in the United States use reverse osmosis to solve the same problem - removing arsenic from water.
Reverse osmosis system used in the USA: the pressure of water on the side of the synthetic membrane, where the contaminants are located, exceeds the pressure of clean water on the opposite side. In accordance with the laws of hydrostatics, water seeps through the membrane, clearing up the road.
Currently, organic harmful substances in water are trying to turn them into harmless nitrogen through reactions, carbon dioxide and water. Serious anionic contaminants such as nitrates and perchlorates are removed using ion exchange resins and reverse osmosis, while toxic brines are dumped into storage facilities. In the future, probably, bimetallic catalysts will be used for the mineralization of these brines, as well as active nanocatalysts in membranes for the transformation of anions.
2.2 Water reuse
Conservationists are now dreaming of reusing industrial and municipal wastewater that has been treated to potable water quality. But in this case, you have to deal with a huge number of all kinds of pollutants and pathogens, as well as organic substances that must be removed or transformed into harmless compounds. Consequently, all operations become more expensive and more complicated.
Urban wastewater is usually treated in wastewater treatment plants, in which microbes are suspended, removing organic matter and food residues, and then in settling tanks, where solid and liquid fractions are separated. Water after such treatment can be discharged into surface water bodies, as well as used for limited irrigation and for some factory needs. Currently, one of the actively implemented technologies is membrane bioreactors (Membrane Bioreactor). This technology combines the use of biomass suspended in water (as in conventional wastewater treatment plants) and aqueous micro- and ultra-thin membranes instead of sedimentation tanks. Water after MBR can be freely used for irrigation and for factory needs.
MBRs can also be of great benefit in developing countries with poor sanitation, especially in fast-growing megacities, by allowing wastewater to be treated directly, separating useful substances, clean water, nitrogen and phosphorus from it. MBR is also used as a reverse osmosis water pre-treatment; if you then treat it with UV (or photocatalysts that react to visible light), then it will be suitable for drinking. In the future, it is possible that systems for "recycling water" will consist of only two stages: an MBR with a nanofiltration membrane (which will eliminate the need for a reverse osmosis stage) and a photocatalytic reactor, which will serve as a barrier to pathogens and destroy organic pollutants with little molecular weight. True, one of the serious obstacles is the rapid clogging of the membrane, and the success of the development of this area of water purification largely depends on new modifications and properties of the membranes.
Environmental laws also pose a significant barrier: in many countries it is strictly forbidden to reuse water for public use. At the same time, due to the lack of water resources, this is also changing: for example, in the United States, water reuse increases by 15% annually.
2.3 Salt water desalination
Increasing the supply of fresh water by desalination of the waters of the seas, oceans and saline inland waters is a very tempting goal, because these reserves make up 97.5% of all water on Earth. Desalination technologies have come a long way, especially in the last decade, but they still require a lot of energy and capital investment, which is holding back their spread. Most likely, the proportion of large conventional (thermal) desalination plants will decrease: they consume too much energy and suffer greatly from corrosion.
It is assumed that the future belongs to small desalination systems designed for one or several families (this applies mainly to developing countries).
Modern desalination technologies use reverse osmosis membrane separation and thermal distillation. The limiting factors for the development of desalination are, as already mentioned, high energy consumption and operating costs, rapid fouling of plant membranes, as well as the problem of brine disposal and the presence of low molecular weight pollutant residues, such as boron, in the water.
The prospects of research in this direction are determined primarily by the reduction of specific energy costs, and here there is some progress: if in the 1980s they averaged 10 kWh/m3, today they have decreased to 4 kWh/m3. But there are other important successes: the creation of new materials for membranes (for example, from carbon nanotubes), as well as the creation of new purification biotechnologies.
It remains to be hoped that in the coming years science and technology will really make a big step forward - after all, even while remaining almost invisible to many, the specter of the water crisis has long been haunting not only Europe, but the whole world.
CONCLUSION
The problem of ensuring the proper quantity and quality of water is one of the most important and of global importance.
At present, humanity uses 3.8 thousand km 3 of water annually, and consumption can be increased to a maximum of 12 thousand km 3. At the current rate of growth in water consumption, this will be enough for the next 25-30 years. Pumping out groundwater leads to subsidence of soil and buildings (Mexico City, Bangkok) and a decrease in groundwater levels by tens of meters (Manila).
As the population of the Earth is constantly increasing, the demand for clean fresh water is also constantly increasing. Even today, the lack of fresh water is experienced not only by the territories that nature has deprived of water resources, but also by 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.
The limited supply of fresh water is further reduced due to pollution.
The main danger is represented by sewage (industrial, agricultural and domestic). The latter, getting into surface and underground water sources, pollute them with harmful toxic impurities that are dangerous to human health, as a result of which the already limited fresh water reserves are reduced. A person needs clean, high-quality fresh water and it is only in his power to preserve its reserves.
LISTUSEDSOURCES
1. Materials of the scientific journal Nature for 2007
- 71.50 Kb1. The problem of pure drinking water. Degradation of fresh water bodies.
main dzherel zabrudnennya and zam_chennya water
International Dosvіd Conservation and Purification of Fresh Waters
Contamination of surface and underground waters can be subdivided into the following types:
Mekhanichne - promotion to replace mechanical houses, domineering in the main superficial types of confusion;
Chemical - presence in water of organic and inorganic speech toxic and non-toxic;
Bacterial and biological - presence in water of various pathogenic microorganisms, fungi and other algae;
Radioactive - the presence of radioactive rivers in the surface or underground waters;
Teplov - release near the water reservoir for the feeding of thermal waters and nuclear power plants.
The main dzherelami zabrudnennya and zam_chennya water є:
Stichni vodi promislovih and communal enterprises;
Vіdhodi vіd rozrobok ore and non-metallic copalins;
Water mines, mines, oil industries;
Trees come out when harvesting, processing, alloying wood materials (bark, thyrsa, triska, logs, khmiz and іn.);
Wikidi of water, transshipment and automobile transport;
Primary processing of flax, hemp and other industrial crops.
The most intensive fermenters of surface waters are large cellulose-paper, chemical, naphtho-refining, grub and textile industries, food ore and metallurgy plants, as well as agricultural smelting.
Even more unsafe is the rafting of the fox, broken with strong toxic chemicals - antiseptics, which stagnates in the fox industry. Water becomes unsuitable for life and for the life of aquatic organisms. Under the hour of rafting with a rich rich tree tone and rotting on the day, which also leads to an increase in the mortality of living organisms of the aquatic environment.
Sіlsk gospodarstvo is one of the biggest contributors and, at the same time, zabrudnyuvachiv natural waters in the aftermath of victoria, pesticides and other chemicals, the functioning of the great tvarinnitsky complexes, zroshuvannya lands.
More than 50 million tons of nitrogen fertilizers should be introduced into the soil. Everywhere, water is polluted with fertilizers and pesticides, which are unsafe for their toxicity. In rich rural areas with intensive zastosuvannyam nitrogen fertilizers, even today in 50% of wells, water will replace nitrates, and nitrites - already above the norm - 20 mg / l; in the most important vipadkіv їhnіy vmіst syagaє 100-1500, and in the subdecade - more than 2000 mg/l. In the case of severe illnesses, causing deaths in children, they are especially unfavorable. Half-nitrogen and nitrate ions lie down to mutagenic speeches, and lead to genetic diseases. Following WHO data, from 1966 to 1980, the number of people who were born with recessive ailments increased from 4 to 10.5%.
Even unsafe, synthetic miyuchi zaobi, which are consumed by the water basin, and instill an insignificant amount of vibrancy, an unacceptable relish and the smell of water, it satisfies the pin and spit on the surface, which makes it difficult to access the sourness and lead to the death of aquatic organisms. Up to special vistas of straggling, there is also overgrown with water and algae, especially blue-green ones, rotting like some kind of sickness and death of ribeye. This problem is even worse for water bodies in the Dnipro basin.
Especially indecent for healthy "I am the people's scruffy of natural waters with motivated drains. Taka is struck by the water of calling unacceptable for the supplied to the population, the deskilki of the zbodniki of the riznikiyny nye zakhoryuvan (paratif, the diesel, ilno native hepatitis, tulamia). Mayzhe 500 million people are highly alert through the core vanity of water. In indії, for the way, de feckalnі іndvkatsya, Viklikati Veliky Kilkiyni Zakhvoryuvan, for ten-handed (1940-1950 pp.), Slunkovo-Kishkovichi Zhvyvyuvan 27 430 marshmallows.
To terrible naslіdkіv to cause the waters to be polluted with important metals.
In Japan, the massive silt of the waters of the sea inflow near the Minamato place called out the minamato ailment, with a kind of mercury, fish broke out, which is the main body of the protein population of this place. Movie sustained the ailments, the zir sent, the parallers, having crowned M "Jasi, nig. Inshoba - izyoba - Viclikana Khrronsky Kadmіm, Shu is known in the rice. among ailments reached 50%.
In the rest of the hour, the great shkodi will lead the natural waters of acidic rain. Chim is often vipaday, the acidic bilsha concentration of acids is a misty, Tim Shvidsha Zhilkiy, the Vidovy warehouse is living, in the water, I can be guilty of the izhrinki of amphibians, raliki, the vihima of the bacteri, and the abbess of the heater of the heater. From the bottom surpluses, the vilugovuvannya of brittle metals begins: aluminium, mercury, lead, cadmium, tin, beryllium, nickel and other. In the wake of this rich rib guinea in the form of a bad winter, called by a brittle aluminum. In the distance, sour-loving mosses, mushrooms, and some algae grow, as if ignoring the weeds. Guinea riba, perch pike and perch. If the concentration of acid in the water increases further, the ribi in the lake will not be depleted in the river. Toads, komakhs are dying. The water is given clean, shards in the daytime may be all micro-organisms. There are no more anaerobic bacteria, which see carbon dioxide, methane, and circulatory day. The essence of the old development lies in the fact that the natural resources are guilty of vikoristani in such ways, as if they would secure their appurtenance for the future generations.
The steel development of the dzherel vimaga, so that we did not disrupt the hydrological cycle, conserve water resources, which, with such a crust, would not be exhausted for a long time.
However, considering the importance of such a situation, large-scale water systems still continue to grow, not to protect the needs of the future generations, but to inject these systems into the middle ground can still be great.
Наприклад, будівництво Асуанської греблі, хоча і є зараз вигідним, зокрема для фермерів, спричинило затоплення численних археологічних ділянок, зруйнувало цінні екосистеми і риболовні угіддя, викликало появу хвороб, що переносяться москітами, ерозію ґрунтів, порушило баланс поживних елементів і річкових відкладень.
Precisely, all-encompassing evidence of large-scale water projects in the middle of the world and today's social legacy would demonstrate the urgent need for effective conservation projects on a small scale.
Desalination of sea water theoretically could become a permanent reservoir of fresh water, accepted for rich lands, which could provide access to sea water. However, through high energy consumption, water is desalinated in a decade more expensive, lower water, which is supplied in the greatest way, to which Kuwait and other rich lands subsidize water, which is supported by the inhabitants of these lands. For an amount of fresh water per capita, Ukraine borrows the rest of the space in Europe.
We have the least amount of fresh water per person. Let's not marvel at the Polish swamps and the Carpathians. Practically the entire other territory of Ukraine, so that all the steppe and forest-steppe swarms are dry territories, and we really have a shortage of water, as it is not surprising.
About tse to speak Zagalnoderzhavna program of development of the water state, praised by the Law of 17.01.2002 r. No. 2988-III. The low water supply in Ukraine is most likely due to the low leaf density. Water does not get trapped in soil and forest water basins.
The following are the main methods of water purification, mastered on a par with modern technologies:
Mechanical (vіdstoyuvannya) - vikoristovuєtsya for the usunennya z vodi nerozchinnyh domіshok. In the trees, important particles are deposited with a thick layer of over 1 g / cm3, and the lighter particles merge onto the surface. For the help of this method, it is possible to ensure a change in the amount of fermentation with chalky speeches up to 90%, and with organic ones - up to 20%;
Chemical field in coagulation and neutralization of zabrudnyuvalnyh speeches. Okremі nerazchinnі speech in the process of coagulation are transformed in neshkіdlі vіdnі spoluki. Methods of chemical cleaning allow to bring the level of purification of water for a bag of unrefined speeches up to 80-85%;
Physical and chemical development on the basis of a number of methods: 1) flotation - passing water through the water again, the bulbs of some kind of water rise uphill, suffocate from themselves and blame the flow of water for the brooding speech; 2) sorption - the purpose of the building of clay, fermenting speech and accumulating them on its surface; 3) ekstraktsіy - uvedennija at stіchnі vodi rhechovina, yakі can raschinyat zabrudnyuvalnі speechovi; 4) evaporation - passing water vapor through heated sewage water; 5) ionic exchange - ce poglanannya zabrudnyuvalnyh rechovina in the process of filtering through ionic resin; 6) elektrolіz - passing through stіchnі vody elektrichnogo struma in special elektrolіzernih installations. The steps of purification lead after a bag of incoherent speeches to become mayzhe 90%;
Biological is carried out by a path of biological oxidation in natural minds (in the fields of cultivation, at special biological rates, as well as in piece minds - biological filters too). Under the hour of such purification, only 10-40% of inorganic speeches are removed and salts of important metals are practically not removed;
Biochemical - the main method of purification of waste waters, polluted with organic rivers. All biofilters, aerotanks, aerators, and designs of such are constantly being fully restored.
One more step to protect the water is in the fact that between the growing seasons it saves the water, it is recognized for cultivation, in underground gatherings. In most regions, the accumulation of rainwater and snow water and water in the rivers is maximum between growing seasons, if the demand for water is minimal. The main task is to conserve water and vikoristovuvat її in that season, if the need for irrigation in it is especially large. The simplest way is to drain the water behind the auxiliary rowing, proteo from the surface of the water reservoirs to steam up a significant amount. Spend on viparovuvannya can be reduced, so as to save water under the earth. It is possible to vikorate great underground reservoirs, which can easily be filled with water from the surface of the dzherel, and then pump water from them to rise in the world of need. Similar "banks of water" are already in Arizona, California and in other places.
More widely varying doschuvalnyh systems of watering, yakі minimizuyut vitrati vody, allowing їy it is right to come either from the soil ball, or directly from the root zone of the roslin - effective zasіb skorochennya vykorennya vody for іrigatsії. Investing in new varieties of roslin, building water shortages, dry watering and watering with saline water, also allows you to additionally reduce the amount of water to grow. For this use special smіttєvі containers.
Koristayutsya such miynimi zaoborah, yakі not to avenge phosphates, and do not buy the products of concerns, scho zarudnyuyut too much in the middle.
Win only highly efficient dishwashers and dishwashers (marked with the Energy Star sign) and zavzhdat them all.
Install a cistern at the toilet with a hinged button for draining (which allows you to stain less water for cutting) or a dry closet, that system for cleaning and secondary draining of drains.
Install a watering can in the shower with a small stream of water and vicarious water from the bath for watering the rooms.
Water your lawn early in the morning or at night to avoid the cost of steaming.
2 - Problems of the Light Ocean.
oil and other types of pollution
negative impact on the ecosystem and a threat to life in the ocean.
For the rest of the thirty-fifth century, the waters of the Light Ocean significantly sank. The surface is covered with naphtha, plastic packing material, toys, dances and other smitty, which are not laid out near the water. Such solid outputs have piled up already over 20 million tons. Naphtha and petroleum products lie in the oceans of the world up to the largest stubbles. On the shelf, maybe 30% of all oil is found, hundreds of millions of tons are transported by sea routes, on which not less than 1% of oil is spent, tobto 5-10 million tons. I am especially worried about the transport accidents of the great tankers. In 1968 іz "Torricanion" in the English Channel wafted 119 yew. tons of oil, following catastrophes in marine fields near California, in the Pivnichny Sea, in the Mexican and Persian inlets. A lot of birds, plankton, nekton, sea animals become victims of naphtha fermentation. The naphthic spit streaks in the Antarctic waters, where seals and penguins perish. Nafta spoiled a lot of European resorts of light significance. Ninі dієzhnarodna konventsіya schodo zabіgannya zabrudnennya maritime spaces with naphtha, as signed by the largest maritime powers. According to convention, all maritime areas within 50 miles from the coast are fenced zones, where it is not allowed to take oil from the sea.
It is a great concern to make the ocean of the Holy Ocean fermented with radioactive rivulets after the testing of thermonuclear weapons, the burial of radioactive exits, and the operation of nuclear reactors on military underwater channels and crygolams. The radioactivity of plankton can be 1000 times greater, the lower radioactivity of water, and that of fish - more than 50 thousand times. razіv, nizh in the lance of life. Shoroka in the ocean of light from different dzherel consumes over 4 million tons of summer organic pollutants (dichloroethane, freon, etc.), close to 120 yew. tons of chlorinated carbohydrates (DDT, aldrin, benzyl hexachloride, polychlorinated biphenyls and in.), over 300 ths. tons of lead, over 5 yew. tons of mercury, over 10 thousand. tons of cadmium. The region of repeated transference and straying in the wake of ship navigation that works on the shelf, a large number of straying rivers are carried by river runoff, where about 600 billion tons of industrial and butovyh stocks are thrown off. 40% of the volume of light resources of the river runoff is spent on the distribution of sewage waters. The volume of these sewage waters is counted in thousands of cubic meters and it becomes 0.1 to 20% for different seas and more of the river runoff, which falls into them. With the help of industrial effluents, the river will add more mercury to natural wine, 12-13 times more lead, midi, zinc, 30 times more surmine. salt, 2.3 million tons of lead, 5 million tons of phosphorus. and the neutralization of less than a third of the zabrudnyuvachiv.Reshta sinks into the coastal zone of the sea.
Work description
With the development of industry, rivers and lakes have become more and more zabrudnyuvatisya with insufficiently purified sewage waters, industrial outputs and thermal waters of hydroelectric power plants. During the last period, the rivers and lakes were clearly overgrown due to the accumulation of good, pesticides and herbicides from the agricultural lands, as well as acidic woods. Contaminated with industrial wastes, agricultural fertilizers and pesticides has become a real threat.
It is known that the amount of water in nature is practically unchanged. The problem is that the planet's supply of clean drinking water is constantly declining. And this happens with an increasing volume of water consumption.
Mostly fresh water is suitable for use in industry, agriculture and everyday life.
The main sources of fresh (drinking) water - rivers and fresh lakes - are extremely unevenly distributed on the continents. In Europe and Asia, where 70% of the population lives, only 39% of the world's river water reserves are concentrated. In Europe, where almost 20% of the world's population lives, fresh water supplies account for only 7% of the world's total water supply.
There are areas on the planet where there is a catastrophic lack of clean drinking water. So, in one of the African tribes, women rake wet sand for days on end, scooping brown liquid with spoons. Only one or two liters are gained per day (a film was made about this).
On islands southern seas to quench your thirst, you can only rely on rainwater and coconut milk. Often, children are not allowed to play outdoor games, because this makes the child sweat and he wants to drink more.
For a long historical period in regions with natural reserves of clean fresh water, a person fully satisfied his needs for fresh water, without feeling a lack of it. However, due to the intensive growth of the population and its industrial activities, the need for water has steadily increased. At present, it has reached such proportions that in many places on the planet, and especially in developed industrial areas, there is an acute problem of lack of fresh water.
The lack of fresh water is already noted in many countries of the world, it is experienced by 1/3 of the world's population. Thus, Hong Kong, with a population of about 4 million people, receives water through a special pipeline from China. Additionally, it is delivered by tankers. Chronic "water hunger" is experiencing Tokyo. Imported water is partially provided by the state of Algeria. Clean water was transported to Saudi Arabia by plane from New Zealand. Shops in Holland and Japan sell pure water brought from Norway.
Along with the problem of scarcity of fresh water in many regions of the world, there is an acute problem of clean fresh water. There are reports that 1.5 billion people do not have clean water. According to WHO data, almost 3 billion inhabitants of the planet use poor-quality drinking water. For this reason, about 25% of the world's population is at risk of falling ill every year, approximately one in ten inhabitants of the planet is ill, about 4 million children and 18 million adults die. About 80% of all diseases in developing countries are related to the lack of clean water. In addition, water is an invaluable raw material that cannot be replaced by another.
Given all the above reasons, the problem of water supply has become one of the most important in the life and development of human society.
The reasons for the lack of fresh water in the world are as follows: an intensive increase in water demand due to the growth of the world's population and the development of industries economic activity requiring huge expenditures of water resources; losses of fresh water due to the reduction of river flow and other reasons; pollution of reservoirs by sewage.
Losses of fresh water due to the reduction of river flow are mainly due to deforestation, plowing of meadows, drainage of floodplain swamps, etc. This leads, firstly, to an increase in surface runoff and an increase in the volume of water flowing into the seas, and, secondly, to a decrease in the level of groundwater that feeds rivers and maintains their water content. Losses of fresh water in many countries of the world reduce groundwater resources.
To designate this phenomenon, there is a concept - depletion of water.
Water depletion- reduction of the minimum allowable runoff of surface water or reduction of groundwater reserves. The minimum allowable runoff is the runoff at which the ecological well-being of the water body and the conditions for water use are ensured.
In addition, large losses of fresh water occur as a result of:
filtration of water through the walls of channels;
· violations of the integrity (gusts) of the main water conduits supplying water to settlements from water supply sources, and pipes of the water supply network, through which water is diluted through the territory of settlements;
· irrational leakage of water in residential and public buildings as a result of faulty water taps and spillway sewer devices.
The world should expect a further increase in fresh water consumption for various needs of human society.
The shortage of clean fresh water is also due to pollution of natural waters.
Water pollution- introduction into water (water bodies) or formation (synthesis, reproduction, etc.) in it of physical, chemical or biological agents that adversely affect the living environment or cause damage material values. Pollution of water bodies usually occurs as a result of the discharge of sewage into them.
Wastewater- these are waters that were in industrial, household or agricultural use, as well as passed through some kind of contaminated territory, including the territory of a settlement (industrial, agricultural, domestic and storm drains). These are waters discharged after use in household and industrial activities of a person.
The main harmful substances entering water bodies (surface and underground water sources) with wastewater are oil and oil products, phenol, detergent specific surfactants (surfactants), ammonia, pesticides, heavy metals, complex chemical compounds and others. Pathogens of infectious diseases can get into water sources with domestic wastewater.
As a result, surface and ground waters become unsuitable for use in order to provide drinking water supply, domestic and industrial purposes.
Filed by the Moscow Research Institute of Hygiene. F.F. Erisman, in Russia, iron, turbidity, total organic pollution in terms of permanganate oxidizability, phenols, manganese, surfactants and oil products, residual aluminum, formaldehyde, caprolactam, cyclohexanol are most often found in drinking water above the regulated values. In some samples of drinking water, an increased content of arsenic and lead is recorded. The presence of mercury, cadmium, molybdenum, nickel and chromium in the water of some water pipes poses a risk to public health. The appearance of these substances in water can be explained by man-made causes.
In Russia, according to the maximum intensity and area of groundwater pollution by harmful chemicals the most tense situation has developed in the areas of large industrial enterprises - in the cities of Cherepovets (phenols, chlorobenzene, butanol, toluene), Lipetsk (cyanides, thiocyanates), Tula (thiocyanates), Voronezh (surfactants, cadmium), Tolyatti (phenols, aluminum), Volgograd (phenols, molybdenum), Stavropol (cadmium, nickel), Chelyabinsk and Novorossiysk (phenols, lead, iron), Novokuznetsk (phenols, fluorides), etc.
In Ukraine, oil products, phenol, styrene, chlorobenzene, dichloroethane, cyanides, acetone, cadmium, lead, copper, zinc, mercury compounds and other substances can enter water bodies with wastewater. At the same time, the risk of their penetration into drinking water remains.
Concentrations of various chemical elements in drinking water depend on natural and technogenic (anthropogenic) factors. Natural causes are determined by the level of natural content of elements in open water bodies, groundwater, soil and rocks, and man-made causes are determined by the entry of chemical elements into the environment as a result of human activities.
According to published data, chemical elements whose content in drinking water is largely determined by the specific features of biogeochemical provinces include fluorine, iron, barium, titanium, zirconium, vanadium, molybdenum, lithium, strontium, and cobalt.
Biogeochemical province- a separate area of the Earth's surface, which differs from other similar areas in terms of content (excess or deficiency) and composition of chemical elements and substances found in soils, waters, plants and animals.
The content of heavy metals (lead, copper, nickel, zinc), as well as manganese and chromium, in drinking water depends both on the geohydrochemical characteristics of the territory and on the specifics of the technogenic impact on the environment. Experts have found that if the concentrations of various metals in drinking tap water exceed the background level, this is a confirmation of their technogenic, and not natural, origin.
Heavy metals in sources of drinking water supply and, accordingly, in drinking water in different territories are distributed extremely unevenly. Yes, in settlements Donetsk region concentrations of lead were found in drinking water: maximum 3.6 GTDC (Shakhtersky district) and minimum 0.4 MPC (Mariupol), nickel - maximum 2.7 MPC (Starobeshevsky district) and was not detected in any water sample in six rural districts, chromium - 3.4 MPC (Pervomaisky district) and was not found in any water samples in 4 districts. The maximum concentration of manganese reached 8.6 MPC (Pervomaisky district), while in the drinking water of most cities in the region this metal is found in low concentrations and usually does not exceed the hygienic standard.
According to American scientists, the use of pesticides in agriculture can lead to local and regional contamination of drinking water sources. The content of pesticides in the water of open reservoirs and groundwater varies greatly depending on the seasons of the year and local geological features. The highest concentrations of these substances are observed in the waters in spring and early summer after heavy rains. Pesticides are found in almost 50% of the studied groundwater samples taken in the United States.
Total according to the American Environmental Protection Agency (Agency for the Protection Environment- EPA) and other US organizations, more than 160 active ingredients of pesticides are known to be carcinogens or suspected of being carcinogenic.
Cases of extremely high pollution of drinking water with harmful substances of technogenic origin pose a significant danger to the population. This usually happens during various accidents.
As a result of the accident at the Chernobyl nuclear power plant, which occurred on the night of April 25-26, 1986, a territory of 2712 km2 in Ukraine was dangerously affected by radiation, which is completely excluded from national economic use. The decay period of some isotopes reaches 130 years. By-product Chernobyl disaster was the contamination of water sources and, as a result, drinking water with radioactive isotopes. This led to a shortage of clean natural iodine R disaster zone.
Pollution with harmful substances of drinking water of centralized water supply can occur in violation of the law - in the case of connection by responsible persons of water supply networks of drinking water supply with networks supplying non-drinking water, that is, technical or industrial water supply. For example, on June 20, 1987, in the city of Kommunarsk (now the city of Alchevsk, Lugansk region), in the village of Gorky, there was a significant contamination of drinking tap water with oil products. Early in the morning, a liquid, a mixture of water and oily substances, poured from the open water taps of the inhabitants. As a result of the investigation, the fact of connecting the drinking water supply networks of the village with the circulating water supply system of the rolling section of the consumer goods shop of the metallurgical plant was established. In order to feed the technological system with drinking water, the workers of this workshop directly (“without breaking the jet”) connected the drinking water conduit to the water supply unit of the reverse cycle of the cooling system for heating furnaces and rolls of rolling mills. At the same time, water from the sump, which accumulated a large amount of oil products, was used to cool these units. The identity of the oil products selected in the sump of the workshop and contained in the water of the drinking water supply system was established. On the fact of this violation of the city SES, the perpetrators were fined and the relevant material was sent to the city prosecutor's office. Normal water supply of the village was restored.
Scientists in many countries are busy with the problems of cleaning polluted waters, desalination of sea salt water and the search for new sources of life-giving moisture. There are projects to tow Antarctic icebergs to the coast of California, Saudi Arabia and other countries.
American specialists have made calculations according to which six tugboats can transport an iceberg weighing about 10 billion tons. Such a mountain of ice can supply fresh water large region during the year.