Modern man uses fresh water for a wide variety of needs. First of all, of course, a person needs water to maintain life, for cooking and drinking, as well as for personal hygiene.

In the economic activity of a person, water is consumed many times more than is required for his domestic and physiological needs.

In matters of water use by humans, a large number of statistics have been accumulated, which with sufficient reliability reflects the real picture.

It is believed that if a person of the Stone Age managed ten liters of water a day, then a modern person already needs 220-230 liters. At the same time, no more than 5 percent of this amount will be spent on his physiological needs (drinking, cooking).

A person, when breathing, daily emits 0.4 liters of water, through the skin during sweating - 0.6 liters, by direct route with urine - 1-1.5 liters, i.e. up to 2.5 liters in total. A person recovers this loss of water by consuming almost the same amount of water per day. It turns out that an adult weighing 70 kg during his adult life (65-70 years) consumes 64 tons of water, i.e. 1000 times its own weight.

The water in the human body is completely replaced in an average of 17 days.

No human economic activity is possible without water. Take agriculture. To grow grain, vegetables, fruits, water gardens, feed and water pets, you need a huge amount of fresh water. For fields, there is often not enough water, which is brought by rains; artificial irrigation is required. For more than one millennium, people in different parts of the Earth have been creating irrigation structures and reservoirs, laying canals. Irrigation from rivers annually takes about 3000 km 3 of water, or 68% of the total water intake.

For industry around the world, about 1000 km 3 of water is consumed annually, which is taken from rivers, lakes and seas. About half of this amount is used in thermal power plants to produce steam, hot water and cooling generators, and the rest is used in other enterprises and transport.

The volume of withdrawn water would be even greater if there was no return water supply in the industry, i.e. multiple use of the same water.

All power plants, internal combustion engines, turbines, nuclear reactors, etc. require cooling for their normal operation. The most commonly used cooling agent is water. The working process of all the listed devices and mechanisms proceeds in such a way that as soon as heat is received in their working area, part of this heat, and quite significant, must be removed immediately. The removed heat is not always able to be used for other needs, and it is thrown into the air by means of cooling water. Well, on engines and generators where an air cooling system is used, the waste heat is emitted into the air either directly or using fans.

This thermodynamic disadvantage of power plants has to be tolerated, because their materials of construction and lubricants can withstand working loads only within limited temperature limits.

According to statistics, at present, about 4400 km 3 of water per year from rivers and lakes all over the world leave for domestic, agricultural and industrial needs. Compared to the world's fresh water reserves, this water consumption is very small: only 10% of the annual river runoff, 5% of the volume of fresh water in lakes and less than 0.5% of fresh water in glaciers. It would seem, what is there to be especially worried about?

It should be noted here that the share of fresh water in the total volume of water on Earth is insignificant and amounts to only 2 percent (about 32 million km 3). Moreover, 80% of this amount is almost inaccessible for use, because it is water from glaciers located in Antarctica, Greenland, as well as near the North Pole and on the tops of high mountains.

Freshwater is unevenly distributed across the globe. There are many arid regions on Earth where fresh water is sorely lacking. In these conditions, at least one billion people out of the six billion people that make up the entire population of the Earth now live. As the population grows, the problem of water supply will only worsen.

And the point is not even the size of the population, but the fact that there is less and less pure water. Natural waters have been polluted for several centuries as a result of human economic activity. Dirty sewage, pesticides, washed away by rain from fields, gases from industrial enterprises and vehicles dissolved in water, discharge of untreated industrial effluents into rivers and lakes - all this destroys water.

Already, the annual flow of rivers around the world is not enough to dilute all wastewater to bring them at least to the minimum acceptable level from the point of view of medicine and sanitation.

Under these conditions, actions such as the use of clean drinking water for watering the streets and for the operation of water closets (WC) and even washing dishes under running water from the tap cannot be considered normal in any way.

The UN Commission examined the quality of drinking water in 122 countries around the world. From a survey report published in 2003, it follows that at that time the cleanest water was in Finland. It was followed by Canada, New Zealand, Great Britain and Japan. Russia was in seventh place (and this is very good!). in last place was Belgium (which is very strange!). cleaner than in Belgium, the water was even in India, Sudan and Rwanda.

Now no one is surprised that in the shops of cities and towns in Russia and other countries, along with mineral water, ordinary drinking water is sold. Household water filters are in great demand. Enterprising people find an opportunity to benefit even from the deteriorating clean water situation. For example, the French brewery Fischer produces beer, the 0.33 liter bottle of which cost 80 francs (almost $ 12) in the first year of production (2000), and is now slightly cheaper. Why is the price so high? It turns out, according to the firm, this beer is brewed in water from Greenland ice, which is 250 thousand years old. This beer is called "63 o N / 46 o W", which means the coordinates of the point from which the ancient ice is taken: 63 degrees north latitude, 46 degrees west longitude.

The degree of pollution of natural waters and the pace with which this pollution occurs, require urgent action from humanity. The ecological catastrophe has already begun, and we have no right to pretend that nothing is happening. But in order to deploy on a global scale really necessary work to save water and air, the main thing is needed: the political will of the leaders of all states without exception and their concerted actions. Otherwise, our grandchildren (not to mention great-grandchildren) will not have to enjoy the fresh air and crystal clear, fresh and tasty water in normal natural conditions. And this will already look like a crime of living generations against subsequent generations and before Nature itself.

The purpose of the lesson: to form students' understanding of water consumption and the current state of the aquatic environment, as well as the main environmental problems associated with the economic use of fresh water sources, and rational water use.

Equipment and materials: technical teaching aids (projector, computer, electronic presentation of the lesson), illustrative material, cards with assignments, sheets of Whatman paper, markers.

Completing assignments

Exercise 1. Remember the properties of fresh water.

List the physical and chemical properties of water known to you and write them down on a Whatman paper. Recall the meaning of the key concepts: water cycle, water supply, wastewater discharge. ( Three aggregate states of water, water density 1 g / cm 3, ice formation at a temperature of 0° C, boiling at 100° С, transparency, ability to dissolve substances, necessity for life support.)

Task 2. What bodies of water are fresh?

Remember and list the types of freshwater bodies. ( Rivers, streams, lakes, ponds, swamps, canals, underground waters. It should be recalled that reservoirs are of both natural origin - rivers, lakes, swamps, and those created by man for a specific purpose - ponds, reservoirs, canals). Which of the listed water bodies may be suitable for water use, and which are not, and why? ( The most suitable are rivers and underground sources.)

Task 3. How and what is fresh water used for?

List all possible household needs for which a person uses water, and arrange them in the form of a pyramid.

Explanation of the new material

1. Sources and uses of fresh water

People use fresh water for various economic needs, of which the main place is occupied by irrigation of agricultural land and energy production. To a lesser extent, water is consumed in industry and for domestic needs, including drinking water. Surface natural waters (mainly rivers, lakes) and groundwater are used as sources of fresh water.

2. We take water "on loan" from Nature

All the water we use is taken out of the natural water cycle and returned to it, already polluted, with a lot of waste. Domestic and municipal wastewater flows into rivers, bays and seas through the city's sewerage system. Industrial enterprises, as a rule, are located on large natural reservoirs, where they receive an unlimited amount of water, use it and dispose of it with waste. The washing away of water from the fields, together with the fertilizers and chemicals contained there, also pollute natural waters.

3. Environmental issues

The use of water for economic purposes gives rise to the following problems.

A. Natural sources can only provide a limited amount of water. There is a danger of excessive consumption of river water and significant changes in the ecosystems of catchment areas. For example, the drainage of water from a river can affect the condition of adjacent marshes and floodplain meadows - they dry up, because are not fed by periodic floods; as a result, the species composition of such ecosystems changes.

B. The use of groundwater leads to a reduction in their supply and subsidence of the soil. The volume of groundwater exceeds that of surface water by 70–80 times, but groundwater is also depleted if its water consumption is faster than replenishment. With a decrease in the volume of groundwater, a gradual subsidence of the land surface can occur, called subsidence. In settlements, this leads to the destruction of roads, building foundations, water supply and sewerage networks, on the coasts - to flooding and destruction of the coastal zone.

V. The water that returns to nature is heavily polluted. This is dangerous for both human health and the environment, especially water bodies. The wastewater of a medium-sized city contains the following pollutants:

- soil washed away in the process of destruction;
- residues of fertilizers, insecticides and herbicides used in gardens and parks;
- various chemical compounds formed during the wear of the road surface;
- soot and toxic substances of vehicle exhaust gases;
- fuel and engine oil from roads and parking lots;
- garbage and plant residues;
- waste water of residential premises and enterprises;
- waste from industrial enterprises using water (the largest amount of pollutants is provided by the pulp and paper industry).

Pollution of surface and ground waters

G. Bioaccumulation of toxic substances contained in water. The greatest problem with the pollution of natural waters is created by various pesticides contained in household, industrial, agricultural and other waste waters. They are present in low concentrations, are difficult to remove from waters, and can also accumulate in living organisms for a long time.

Most pollutants belong to two groups: heavy metals (lead, mercury, cadmium, iron, chromium, etc.) and synthetic organic compounds (benzene, phenol, dioxins, hexachlorocyclohexanes, chlorinated biphenyls, and many others). All pesticides present in the environment in small doses for a long period are dangerous due to their ability to accumulate in the body, which leads to mutations, cancer, and various pathologies.

In nature, toxins move along food chains, at the last links of which their concentrations can increase hundreds of thousands of times compared to the environment.

Completing assignments

Task 4. Make a diagram of the water cycle, taking into account all types of its "withdrawal", use and discharge of contaminated water (various types of pollution - industrial, agricultural, household, etc.) back into natural water bodies. You can complete this task first on a Whatman paper or blackboard, and then in notebooks. Start the diagram with a typical water source - a river.

The main conclusion: clean water is taken from the closed cycle of the water cycle, and polluted water is returned; pollution enters natural reservoirs, from where water is again taken for use. The increase in the level of pollution of natural water bodies has a detrimental effect on living organisms and on the quality of drinking water.

Task 5. Interview the students in your group on the following questionnaire and analyze the situation with drinking water consumption.

- Who drinks tap water at home, and who buys it in bottles?
- Who has ever drunk water in other cities of Russia? In other countries? How different is our water from foreign water?
- Do you use water filters at home?

Explanation of the new material

4. Delivery of water to the consumer

(Conducted using the handout.)

Household water is usually taken from the river or from underground sources in the water intake area. In the Kaliningrad region, this is the Pregolya river, a group of drinking lakes and groundwater in some parts of the region. Water purification and preparation usually goes according to the following scheme:

reservoir ––> coarse filters to remove large impurities ––> reservoir for sedimentation of water (small impurities are removed) ––> disinfection of water to destroy pathogenic microorganisms (usually chlorination) ––> flocculation (sedimentation of suspended solids in water on the sediment of aluminum hydroxide ) ––> passing through sand filters ––> purified water reservoirs ––> water supply network ––> consumer.

Figures and facts:

- the average Russian consumes 272 liters of water per day;
- about 50 million people in our country drink water with a high iron content;
- in recent years, about 750 chemical compounds have been found in water bodies, of which 600 are carcinogenic and are practically not rendered harmless at waterworks.

5. Caution! Tap water!

The main reasons for the poor quality of tap water are:

- pollution of water intakes;
- the use of chlorination;
- poor quality of water supply networks;
- imperfection of sand filters.

The greatest danger in the preparation of drinking water is the technology of its chlorination, since it leads to the appearance in the water of the so-called "combined chlorine" - the result of the interaction of chlorine and some organic compounds. Among the chlorination products there are carcinogenic and toxic compounds, odorless and practically not removed by boiling and settling water (these include substances such as lindane, dioxins, butyl chloride, trichlorophenol, etc.).

The contamination of drinking water also depends on what material the water pipes are made of. For example, cast-iron water pipelines, laid more than 80 years ago, are still working properly. But the steel pipes laid in the 1970s. have already caused a lot of trouble. In addition, due to the poor quality of the pipes, the iron content in the water exceeds the GOST standards.

Final tasks

Assignment 6 (performed in groups). On the already disassembled scheme of “water withdrawal”, find the areas corresponding to the greatest contribution to water pollution (both natural and consumer). Suggest how you can minimize harm to nature and human health.

Task 7. Alternative water sources.

(Students are given cards with images of alternative sources of water supply: forest lakes, swamps, underground sources.)

Provide an analysis of the pros and cons of a specific alternative source in comparison with the currently used ones according to the following criteria:

- purity of water in the source;
- capacity of the source (whether there is enough water to supply the city);
- Convenience of water intake;
- delivery of water to consumers.

The main conclusion: the best solution to water supply problems is to improve the ecological state of the currently operating water sources.

Task 8. Purification of tap water at home.

At home, you can very easily organize water purification by freezing (recrystallization). Find an enamel pot with a lid that fits in the freezer of your refrigerator. Fill a saucepan with boiled water at room temperature so that a gap of 3 cm remains between the lid and the water (in this case, the water will freeze from below and from the sides, and under the lid itself will not have time to freeze in a day). The water should freeze by half or two-thirds. Brown, unfrozen water containing dirt will remain in the center of the pan. This water must be drained, the remaining ice rinsed and melted. It should be remembered that the composition of the obtained water is close to distilled, and there are no salts of calcium, magnesium, etc. in it, so before using this water for drinking, it is necessary to make up for their deficiency.

Handout for the lesson

Water intake station - lifting water to treatment plants	Using pumps	A lot of energy is consumed
Removal of coarse debris and particles in the water	Passing water through special grates
Water settling tank	Small impurities are removed
Water disinfection (chlorination)	Adding chlorine from cylinders, chloramine or sodium hypochlorite	Chemical consumption
Flocculation	Precipitation of impurities with aluminum hydroxide	Consumption of chemicals
Passing through sand filters	Removal of residual suspended solids and impurities
Purified water tank	Water is prepared for delivery to the water supply network
Water supply network - sending water to the consumer	Pumps pump purified water into the water supply network	A lot of energy is consumed

Of the 1,018 tons of water on Earth, fresh water accounts for only 3%, of which 80% are inaccessible for use, since they are ice that forms the polar caps. Fresh water becomes available to humans as a result of participation in the hydrological cycle, or the water cycle in nature, which is schematically shown in Fig. 12.3. Every year, as a result of evaporation and precipitation in the form of rain or snow, approximately 500,000 km3 of water is drawn into the water cycle. Theoretically, the maximum amount of fresh water available for use is approximately 40,000 km3 per year. We are talking about the water that flows from the surface of the earth into the seas and oceans (the so-called runoff).

The water cycle in nature has been known since the Old Testament biblical times:

“All the rivers run into the sea, - and the sea will not overflow,

To the place where the rivers run -

They continue to run there. "

Ecclesiastes 1: 7.

Rice. 12.3. The water cycle in nature.

The use of fresh water is usually subdivided into repeated use and irrecoverable expenditure. In accordance with this, fresh water is also sometimes subdivided into reusable and irretrievable.

Reuse of water can be illustrated with examples such as navigation, fish farming, and hydropower generation.

Irretrievably consumed fresh water is no longer available for reuse. This includes fresh water, which after consumption was lost as a result of evaporation (including plant leaves); water included in the composition of products, as well as runoff water that reaches the sea (ocean) and mixed with salt water. The irreversible consumption of fresh water around the world ranges from 2500 to 3000 km3 per year, and of this amount, approximately 10% is spent for domestic purposes, 8% in industry, and the overwhelming majority -82% is used for irrigation in agriculture.

Water consumption

Domestic water consumption. For domestic purposes, water is used for drinking, cooking, washing, washing, flushing sewage down the drain and watering gardens and streets.

In Europe, the average per capita domestic water consumption is approximately 230 liters per day. This is about the same as in the days of the Roman Empire. For domestic purposes, approximately 10% of all water consumed by humanity is consumed.

Industrial water consumption. Over 85% of the water used for industrial purposes is consumed in cooling processes. The rest is consumed in the processes of washing, flushing gases, for hydrotransportation and as a solvent. Approximately half a million liters of water is consumed for the production of each passenger car; this amount includes both irrevocable water and recyclable water.

For industrial purposes, approximately 8% of all water used in the world is consumed.

Water consumption and agriculture. Agriculture accounts for 82% of the world's water use. This water is used for irrigation. Growing one ton of cotton requires 11,000 million liters of water. Growing ripe pumpkin requires 150 liters of water.

Water consumption for hydropower generation. Over 50% of all UK water inflow is consumed by power plants. Water is used in hydroelectric power plants, as well as in thermal power plants - to create steam that turns turbines and for cooling purposes. Although power plants consume a huge amount of water, it is used practically without losses, in a closed cycle.

It is estimated that by the twenty-first century, global water consumption should exceed natural water intake. To solve this problem, various methods of obtaining fresh water are being developed, which are described below.

Increased inflow of fresh water. Most of the water flowing from the surface of the earth into the oceans is wasted for human needs. Building reservoirs and drilling wells to extract groundwater increases the amount of water used by humans before it reaches the oceans.

In hot weather, large amounts of water are lost from lakes and reservoirs through evaporation. This can be prevented by covering the surface of the water with a thin film of hexadecanol-1 alcohol.

Use of seawater and brackish waters. Fresh water can be obtained from seawater by desalination as a result of vacuum distillation in evaporators.

Distillation of water in them is carried out under reduced pressure. However, this method is energy intensive and economical only in countries such as Kuwait, where energy is available at relatively low prices and rainwater is scarce.

Fresh water can also be obtained by electrodialysis (see Section 10.3) from brackish water. Such water is found in river mouths; it has an intermediate salinity between fresh river and salt sea water.

Currently, there are over 2,000 desalination plants operating all over the world. For water demineralization, not only vacuum distillation and electrodialysis methods are used, but also methods of freezing, ion exchange and reverse osmosis.

Water is the main element of life support for our entire planet. All living beings began their development from her. Few people know that there are a huge number of types of water. They differ in their chemical and physical properties. People today successfully use the properties of solid water. This vital substance is in demand not only in everyday life, but also in cosmetology and production.

Structured water

The human body is 80% water. This figure may vary slightly depending on age and general health. Many living beings can exist without food for a long time. But few people manage to live without water. Although a lot also depends on its quality. Scientists have long been interested in the question of why mountain residents have a good life expectancy. The solution was in the water, which has a special composition.

In mountain springs, water appears in places where snow begins to melt. This is what determines its properties. Molecules are combined into macromolecules and ordered. As a result of numerous studies, it was revealed that the properties of water in a solid state are similar to that which fills the human body. Structured melt water has been found to have tremendous health benefits. It penetrates the cell membranes much more easily, carrying with it nutrients, vitamins and microelements. It is no coincidence that structured water is widely used for cosmetic purposes. One has only to wash her face daily, and her face will shine with health and youth.

Living and dead water

People have known about the healing properties of water since ancient times. Natural clean water, which is found in mountain springs and rivers, can help in the treatment of a serious ailment and prolong life. It is customary to call it alive. It is also found in nature and it is found in abandoned lakes and wells. Stagnant water, on the other hand, poses a risk to human health.

Science does not stand still. Today, living clean water is not uncommon. In order to take advantage of its unique properties, it is not at all necessary to go to a mountain river. A quality product can be obtained through electrolysis. Special devices are used - activators. Under the influence of current, negative and positive ions are formed in the water. The liquid acquires alkaline properties, and its composition becomes identical with water in mountain rivers. Living water promotes the digestibility of food, improves blood circulation. The product is also used in cosmetology.

Drinking water

In ancient times, there was no question of where to get water for daily use. After all, the ecological situation was not as serious as it is now. The huge number of factories and cars, global warming and population growth have taken their toll. At the beginning of this century, 40% of the world's inhabitants were affected. Scientists predict that this figure will increase significantly in a few decades. After all, the water in the river without preliminary purification cannot be used in everyday life.

In our country, drinking water is supplied to people through the central water supply. It is taken from underground sources. But before it becomes possible for humans, it is subjected to numerous purifications. In many sources, it may not be drinkable. It is demineralized and used in industry and production. The properties of solid water allow it to be used to cool various appliances.

Fresh water

Fresh water is considered to be with a minimum salt content. In some sources, this figure reaches only 0.1%. In this case, the water is not necessarily in the form of a liquid. It can also be in the form of gas or ice. It should be noted that the reserves of fresh water on the planet are negligible and occupy only 2.5%. At the same time, only 1% is available to people for use in everyday life. How does a person use the properties of water? It all depends on the ultimate goal. Fresh water can be used for cooking, for cosmetic purposes, for cooling industrial appliances, etc. In most cases, salty water will not work.

Every day the supply of fresh water is decreasing. This is caused by environmental pollution, significant population growth, and the greenhouse effect. Very soon, other types of water will have to be used for domestic purposes. In the meantime, scientists are doing everything to learn how to extract fresh water by artificial means. People create reservoirs and learn to save.

Main sources of fresh water

First of all, water from surface sources is used. These are rivers and lakes. In everyday life, pre-purified underground water can also be used. Part of the fresh water is obtained from precipitation. A huge supply of liquid is in glaciers (over 80%). Global warming can lead to the fact that the glaciers begin to melt, the amount of fresh water will decrease. And the properties of water in a solid state can be successfully used to preserve such a product necessary for life.

Today the main reserves of fresh water are concentrated in Brazil. The second place is taken by the CIS countries. Lake Baikal alone contains 20% of the world's reserves. Its volume is more than 20 thousand cubic kilometers. The composition and properties of the lake water are distinguished by their uniqueness. Baikal allows you to improve your health, as well as to put your psychological state in order.

Tap water

Water enters apartments and houses through a special system - a water supply system. The liquid pre-passes through several stages of purification. If you additionally install a filter at home, you can drink water directly from the tap. The system for providing it is formed with the help of metal pipes. The gaseous property of water directly depends on the quality of communications. Liquid with additional impurities evaporates quickly when exposed to high temperatures. It is undesirable to eat such water.

Before water gets to people, it is passed through a purification station. Here it is defended, filtered through special gratings, primary and secondary chlorination is carried out. Such procedures allow you to remove harmful impurities, rid water of pathogens. If the treatment plant is working properly, tap water can be consumed as food.

Hard water

Tough is one in which magnesium and potassium salts are heavily concentrated. There are various types of water with additional impurities. This is general stiffness, temporary and permanent. is determined by the concentration of all salts in the water in the primary state. The constant can be determined only after boiling water. The amount of chlorides and sulfates is determined. These salts do not break down under the influence of high temperature, and also do not precipitate.

The temporary stiffness can be changed. This also happens during the boiling process. At temperatures above 80 degrees, hydrocarbons are destroyed. As a result, a carbon dioxide precipitate is formed. That is why after boiling the water becomes much softer. How does a person use the properties of soft water? This liquid will be more palatable. For cosmetic purposes, hard water is also undesirable.

How to determine water hardness?

There are several signs that can help you determine if the amount of salt in the water is exceeding the norm. Take a look at the clothes after washing. If they become harder, and the white color becomes yellowish, you should pay attention to the composition of the water. Detergents can react with salts. This can be noticed even when washing dishes. Less foam will form on the washcloth and white flakes may appear.

Limescale is the first sign of water hardness. If the kettle quickly becomes overgrown with sediments after boiling, you should think about purchasing an additional cleaning device. After washing with hard water, a feeling of tightness and dryness appears. The liquid simply washes away the skin's natural protective layer. Soft water, on the other hand, keeps your face hydrated.

Deionized water

Deionized water is the purest liquid, which is this type of water? Primarily in cosmetology. Various masks and creams prepared with deionized water have excellent properties. The skin becomes hydrated, wrinkles and blackheads are reduced. Deionized water can also be used in medicine. Various medications are prepared on the basis of the liquid.

Distilled water

Water for industrial purposes is purified by distillation. Thus, a liquid is obtained without harmful impurities and pathogens. At the same time, there is no need to remember about the beneficial properties of water. The surrounding world does not have a liquid with a similar composition. The problem is that during the cleaning process it also gets rid of beneficial microorganisms. This water is also called "dead". Such a liquid has special physical properties. It has low electrical conductivity and boils at higher temperatures. Distilled water is used in heating systems, when cooling various elements of devices.

Double distilled water

Double distillation is another one from impurities and microorganisms. The result is an absolutely pure liquid. Such water has a conductivity of less than 1 μS / cm. How does a person use the properties of this kind of water? Purified liquid is primarily used in medicine. High quality water is needed for injections. This liquid is also used in various laboratory tests.

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Statistics of drinking water consumption by humans and its importance in everyday life

27.05.2014

Some facts about the Earth's water resources

Man is 70% water.

If all the Earth's water is evenly distributed over its surface, then the average depth of the resulting "reservoir" will be 2.5 km.

If all of it was collected in one drop, then the diameter of this drop would be equal to 1,500 km.

Fresh water bodies occupy no more than 3% of the Earth's area and contain 5 thousand times less water than oceans and seas. But even of this amount of liquid suitable for a person, no more than 1% can be used, since the remaining 99% is polar ice, and snow-ice formations of high mountains.

Drinking water consumption in different countries and its geographical distribution

According to scientists, over the past century, the rate of water consumption is several times higher than the rate of population growth on the planet. By 2050, it is expected that about 80% of people will be born in water-deficient regions with poor sanitation. Basically, this applies to the countries of South Asia and Africa.

The states with large, renewable fresh resources are in the most favorable conditions. These are Canada, Russia, Brazil and some other countries.

However, there are states with a shortage of natural water (UAE, Kuwait, Saudi Arabia), but consuming more of it than their renewable reserves allow. In numbers, consumption in these countries ranges from 250% in Saudi Arabia to 2000% in Kuwait. These are imports purchased from the sale of oil and gas.

Some African countries are in the worst position, where consumption is no more than 100 cubic meters. per year, per person (taking into account the consumption of agriculture, which requires more water than a person needs).

Interestingly, more water is needed for human household needs than for industry and agriculture. For example:

• For the production of 1 ton of steel, about 280 tons are consumed; for 1 ton of paper - 700 tons; to grow 1 ton of wheat - 1.5 tons are required.
• The most water-intensive industry is electricity generation - 44% of all water consumed by industry.
• Developed countries consume from 150 to 400 liters per day per person, with consumption rates ranging from 105 liters to 175 liters.

Obviously, more than half is wasted.

How much water does one person consume in everyday life?

It is calculated that a person spends at a time on:

• hand washing 6-8 l
• teeth cleaning 6-8 l
• showering with about 14 liters of water per minute
• bath taking about 150 l
• flushing the toilet bowl about 6 l
• dishwasher cycle 12-24 l
• washing machine cycle - 25-50 l

Existing physiological consumption rates

In addition to water consumption norms necessary for sanitary and hygienic use, there are physiological standards for water consumption, calculated by the International Health Organization. In Europe, the average drinking per capita is about 2.5 liters per day.

What does a person's daily water intake depend on?

The daily rate required to maintain the vital functions of the body depends on:

1) age. Older people, due to reduced physical activity, require less fluid than younger people.

However, a lack of water in the body of an elderly person can lead to the occurrence of cardiovascular diseases. Elderly people are advised to consume at least 1.7 liters per day.

The amount required for children directly depends on the weight of the child, because children lose much more fluid than an adult under the same conditions. For instance. A child weighing 10 kg needs at least 1 liter of fluid per day every day.

2) physical activity of a person... People with increased physical activity have increased sweating, and their daily intake should be at least 4.5 liters per day.

3)climatic conditions... The human body temperature is maintained by balancing heat production and heat transfer. Among other factors, heat transfer occurs due to perspiration, which depends on the temperature and concentration of water vapor.

There is no heat transfer when the air and skin temperatures are the same. If the air temperature is higher than the skin temperature, then sweating is present. Sweating in hot weather with varying physical activity can lead to a loss of 0.3 liters to 2.0 liters per hour - with great physical exertion.

Dehydration of the body very dangerous, especially for children, the elderly and those with poor health. It is recommended in such conditions to consume 2.5-3.0 liters of water per day, and during increased physical activity - up to 6 liters of water per day.

4) the gender of the person. Taking into account the physiological differences in the bodies of men and women, different norms of water consumption are also recommended for them. For middle-aged men - an average of 3 liters of water per day, and for women at least 2 liters of water per day.