Is there any information about water?

Properties of water

Water (H2O) is an inorganic substance composed of hydrogen and oxygen. It is a colorless and odorless transparent liquid at normal temperature and pressure. In nature, pure water is very rare. Water is usually a solution of acids, alkalis, salts and other substances. It is still customary to call this aqueous solution water. Pure water can be obtained through several distillations using platinum or quartz vessels. Of course, this is pure water in a relative sense and cannot be absolutely free of impurities. Water is a substance that can transform between liquid, gas and solid states. Solid water is called ice; gaseous water is called water vapor. When the water vapor temperature is higher than 374.2°C, gaseous water cannot be converted into liquid water through pressurization.

At 20℃, the thermal conductivity of water is 0.006 J/s?cm?K, the thermal conductivity of ice is 0.023 J/s?cm?K, and the density of snow is 0.1×103 kg/m3, the thermal conductivity of snow is 0.00029 J/s?cm?K. The density of water is maximum at 3.98℃, which is 1×103kg/m3. When the temperature is higher than 3.98℃, the density of water decreases with the increase of temperature. At 0~3.98℃, water does not obey the law of thermal expansion and contraction. , density increases with increasing temperature. When water is at 0°C, the density is 0.99987×103 kg/m3. When ice is at 0°C, the density is 0.9167×103 kg/m3. Therefore ice can float on water.

Water has strong thermal stability. When water vapor is heated to above 2000K, only a very small amount will dissociate into hydrogen and oxygen. However, water will dissociate into hydrogen and water under the condition of electricity. It has great cohesion and surface tension. Except for mercury, water has the largest surface tension and can produce obvious capillary and adsorption phenomena. Pure water has very weak electrical conductivity, while ordinary water contains a small amount of electrolytes and has electrical conductivity.

Water itself is also a good solvent, and most inorganic compounds are soluble in water.

At -213.16℃, water molecules will become hydrophobic.

Physical properties:

Molar mass: 18.0153g/mol

Density: water 0.998g/cm3 (20 degrees) ice 0.92g/cm3

Melting point: 0 degrees 273.15k

Boiling point: 100 degrees 373.15k (at 1 standard atmosphere)

Specific heat: 4.184J/(g.K)

The biosphere can be divided into hydrosphere, atmosphere and lithosphere. Water circulates in the above areas as follows:

1. From the ocean or other water bodies, it can also evaporate into the air from animals and plants;

2. From sinking into the sky Ocean, runoff from land into the ocean;

3. Most water vapor evaporates from the ocean and returns to the ocean, but wind blows the water vapor across the land and flows back to the ocean from land runoff, about 36Tt per year. Water evaporates from land at 71Tt per year. There are 107Tt of precipitation every year, which comes in the following forms: the most common ones are rain, hail, fog and dew. Concentrated water can reflect sunlight to form a rainbow.

Shui shuǐ in Chinese characters

(pictograph. Oracle bone character shape. The middle looks like a water vein, and the two sides look like running water. "水" is a radical of the Chinese character. From the word for water, It may represent the name of a river or water conservancy, or the flow of water, or the nature and state of water. Original meaning: liquid falling from the clouds in the form of rain, colorless, odorless and transparent, forming rivers, lakes and oceans. The molecular formula is H2O, which is everything. The main component of living organisms)

1. Same as the original meaning [water]

Water, accurate. ——"Shuowen"

Water is accurate. Accurate and even. Nothing in the world is equal to water. ——"Shi Ming"

The cold air accumulated in Yin is water. ——"Huainanzi? Astronomy"

One of the five elements is water. ――"Shu Hong Fan"

Any water coming out of a plain is a flood. ——"Zuo Zhuan? Huan Gong Year"

Water is called Qingdi. ――"Book of Rites? Qu Li"

Ice is made of water, but it is colder than water. ——"Xunzi? Encouraging Learning"

Liu Yuzhou's royal family was a man of extraordinary talent and talent, and was admired by all scholars, like water returning to the sea. ―Song Dynasty? Sima Guang's "Zizhi Tongjian"

Another example: Shuichou (a small appliance for boiling water); Shuitou'er (turbulence); Shuisheng (water vapor; moisture); Water Gu Disease (water stasis disease); Shuicheng (a small bowl next to the inkstone used to store water for grinding ink); water falling into the trough (a metaphor for a steady and stable heart); water spraying peach blossoms (a metaphor for a good-looking face); Mr. Shui Jing (referring to the Three Kingdoms period) Sima Hui, clear as water and a mirror); Shuilu Zachen (water and land are presented together. All delicacies from mountains and seas are displayed together); Shuijiao (city outline by the water); Shuivortex (whirlpool in the water); Shuiguan (a building or inn near the water) )

2. Specifically refers to the river [river]

In the Mekong River. ——"Poetry? Qin Feng? Jian Jia"

Going back and forth to the river mouth to guard the empty boat, the moon is shining brightly around the boat, the river is cold.

——Tang Dynasty? Bai Juyi's "Pipa Xing (with Preface)"

Another example: Shuikou (ferry); Shui Branch (a tributary of the river); Shui Zhi (a book recording the river system); Shui Dao (referring to Documents describing river systems); Shuigu (mountain ditches); Shuiwei (the end of a river); Water Rat (a thief who specializes in stealing from boats); Shui Shi (matters about river water conservancy); Water Forbidden (prohibitions on rivers) ); Shuihui (the confluence of rivers)

3. Generally refers to all waters [waters]

The water house is deep and dark, and few people are in the dark. Master has traveled thousands of miles, what will happen? - Tang? Li Chaowei's "The Biography of Liu Yi"

Liu Bei and Zhou Yu advanced by land and water. ――Sima Guang's "Zizhi Tongjian" of the Song Dynasty

Another example: Shuilu (water and land Taoist temple in Buddhism); Shuibo (lake); Shuiju (living in a water town); Shuihuang (water god) Ditch); Shui Wang (another name for the sea); Shui Bo (the legendary water god; big river); Shui Su (staying overnight on the water; lodging in the water); Shui Mei (waterways, underground currents); Shui Liao (due to the passage of rain) Water that accumulates in fields or flows on the ground)

4. The general name for juice and liquid [liquid].

Such as: water gifts (gifts such as fruit bait); fruit candies (candies mixed with fruit juice); ink; saliva; tears; potions; sodas

5. Big water ;Flood[flood]

Therefore, Yao and Yu had nine years of water, and Tang had seven years of drought. ——Chao Cuo of the Han Dynasty, "On Guishu Shu"

Said: Does heaven and earth have laws? He said: Floods, droughts and epidemics are the laws of heaven and earth. ——Qing Dynasty? Hong Liangji's "Zhiping Pian"

Another example: Shuibei (facilities to prevent floods); Shuiyong (flood control wall)

5. Star name [morning star] .

For example: Shuixiu (constellation name. Ancient astronomers’ collective name for the seven stars in the north)

6. Official name [official's name].

For example: Shuiyu (an ancient official name. In charge of political orders in Sichuan); Shuiguan (an official in charge of water control and collecting fish taxes)

7. The silver content of currency. The fineness of silver is referred to as currency exchange subsidies and remittance fees [silver content in coins].

Such as: discount; deduct water; collect water; water silk (poor silver)

8. One of the five elements [water, one of the five elements]

The five elements: the first is water, the second is fire, the third is wood, the fourth is gold, and the fifth is earth. ――"Book? Hong Fan"

9. Aquatic animals and plants [water animal or plant].

For example: unable to buy land and talk about planting water, recently the lake has also collected rent

10. It used to refer to the painful living conditions of nuns and prostitutes [deep distress].

For example: Water Bureau (formerly refers to brothels and prostitutes); Shuike (businessmen who run docks, also refers to human traffickers)

11. Additional income or additional fees.

Also, "to make a fortune" means "to make a fortune" [extra income]

12. Refers to the water army [troops fight on the waters]

Everyone is just a fool. The book says that the water moves eight hundred thousand and everyone is frightened. ―Sima Guang, Song Dynasty, "Zizhi Tongjian"

13. Shui nationality [Shui nationality]. One of the ethnic minorities in China, living in Guizhou Province

14. Surname

15. Wubi Divided into II

The source of water

The Earth is the only planet among the eight planets in the solar system that is covered by liquid water. There is considerable academic disagreement over the origin of water on Earth, with dozens of different theories of its formation currently in existence. Some people believe that in the early days of the formation of the Earth, hydrogen in the original atmosphere was oxidized to form water, and the water vapor gradually condensed and formed an ocean; others believe that water was originally present in the nebula material that formed the Earth. Another view is that silicates and other materials in the original crust reacted and released water due to the influence of volcanoes. There are also views that comets and meteorites attracted by the earth are the main source of water on the earth, and even now the water on the earth is still increasing.

Impact on climate

Water has a regulating effect on climate. Water vapor in the atmosphere can block 60% of the earth's radiation, protecting the earth from cooling. Oceans and terrestrial water bodies can absorb and accumulate heat in summer to prevent the temperature from being too high; in winter, they can slowly release heat to prevent the temperature from being too low.

Water in the ocean and on the surface evaporates into the sky to form clouds. The water in the clouds falls through precipitation and turns into rain, and in winter it turns into snow. The water falling on the surface seeps into the ground to form groundwater; the groundwater emerges from the ground to form spring water, which flows into the sea through streams and rivers. Form a water cycle.

Precipitation activities such as rain and snow have an important impact on climate. In the temperate monsoon climate, the monsoon brings abundant water vapor, forming two obvious dry and wet seasons.

In addition, in nature, due to different climatic conditions, water will appear in the form of hail, fog, dew, frost, etc. and affect the climate and human activities.

Impact on geography

71% of the earth’s surface is covered by water. From the air, the earth is a blue planet. Water erodes rocky soil, silts rivers, transports sediment, creates plains, and changes the surface form.

The Earth's surface water bodies constitute the hydrosphere, including oceans, rivers, lakes, swamps, glaciers, snow, groundwater and atmospheric water. Since the water injected into the ocean contains a certain amount of salt, coupled with years of accumulation and evaporation, the water in the sea and ocean is salty and cannot be drank directly. The water in some lakes is also salty. The largest body of water in the world is the Pacific Ocean. The Great Lakes in North America are the largest freshwater systems. The Caspian Sea is the largest saltwater lake in Eurasia.

The volume of water on Earth is approximately 1 360 000 000 cubic kilometers. Of which

the ocean accounts for 1 320 000 000 cubic kilometers (or 97.2%).

Glaciers and ice sheets account for 25 000 000 cubic kilometers (or 1.8%).

Groundwater accounts for 13 000 000 cubic kilometers (or 0.9%).

Lakes, inland seas, and rivers account for 250,000 cubic kilometers (or 0.02%) of fresh water.

Water vapor accounts for 13,000 cubic kilometers (or 0.001%) of the atmosphere at any given time.

Impact on life

Life on earth first appeared in water. Water is an important component of all living organisms. The human body is 70% water; jellyfish are 98% water. There are a large number of aquatic vegetation and other aquatic organisms living in the water.

Water is conducive to chemical reactions in the body and also plays a role in transporting substances within the organism. Water plays a large role in maintaining the stability of temperature in living organisms.

Types of water

Different disciplines have different names for water:

According to different water quality, it can be divided into:

Soft water: Water with a hardness below 8 degrees is soft water.

Hard water: Water with a hardness higher than 8 degrees is hard water. Hard water will affect the effectiveness of detergents, and heating hard water will cause more scale.

Drinking water can be divided into:

Fresh water

Salt water

In addition: biological water : Water in different states existing in various life systems.

Natural water:

Soil water: water stored in the soil

Groundwater: water stored underground

Ultrapure water : Water of extremely high purity, mostly used in the integrated circuit industry

Crystal water: also known as hydration water. In crystalline substances, a certain number of water molecules are combined with ions or molecules by chemical bonds.

The chemical molecular formula of heavy water is D2O. Each heavy water molecule is composed of two deuterium atoms and one oxygen atom. Heavy water accounts for less than 20,000% of natural water, and heavy water obtained through electrolysis of water is more expensive than gold. Heavy water can be used as a moderator and heat transfer agent in atomic reactors.

The chemical molecular formula of superheavy water is T2O. Each heavy water molecule is composed of two tritium atoms and one oxygen atom. Superheavy water is extremely rare in natural water, with a proportion of less than one part per billion. The production cost of super-heavy water is tens of thousands of times higher than that of heavy water.

The chemical formula of deuterated water is HDO. Each molecule contains one hydrogen atom, one deuterium atom and one oxygen atom. Not much use.

In addition, water also includes sweat, salt water, urine, distilled water, etc.

Chemical reactions related to water

Water ionization and solution pH

Water is an extremely weak electrolyte that can weakly ionize: H2O +H2O?H3O++OH- Usually H3O+ is abbreviated as H+

The ion product of water Kw=[H+][OH-]

At 25 degrees, Kw=1×10- 14

pH=-log10([H+])

If pH<7, the solution is acidic; if pH=7, the solution is neutral; if pH>7, the solution is alkaline.

Acidic oxides or alkaline oxides that are soluble in water can react with water to generate the corresponding oxygen-containing acids or bases. Acid and alkali neutralize to form salt and water. Water can decompose into hydrogen and oxygen under the action of electric current. Alkali metals will burn when in contact with water.

Under the action of catalysts, inorganic and organic substances can undergo hydrolysis reactions with water:

Hydrolysis of organic substances: A certain atom or atomic group in the organic molecule is decomposed by the hydrogen atom of the water molecule Or hydroxyl (-OH) substitution, such as the hydrolysis of methyl acetate:

Hydrolysis of inorganic substances: usually the hydrolysis of salts, such as the weak acid salt sodium acetate combines with H+ in water to form a weak acid, making the solution Alkaline:

In addition, water itself can also act as a catalyst.

Freshwater shortage problems and countermeasures

The total water reserves on the earth are about 1.36x1018m3, but excluding saltwater resources such as oceans, only 2.5% is freshwater. Fresh water mainly exists in the form of glaciers and deep groundwater. Fresh water in rivers and lakes only accounts for 0.3% of the world's total fresh water.

The World Meteorological Organization pointed out in early 1996 that water shortage is the primary problem facing cities around the world. It is estimated that by 2050, 46% of the world's urban population will be short of water. For areas with scarce water resources, water has exceeded the scope of living resources and has become a strategic resource. Due to the rarity of water resources, the possibility of water wars is increasing.

In order to draw the world’s attention to the shortage of fresh water resources, the 47th United Nations General Assembly designated March 22 each year as World Water Day.

Beijing’s water situation

Beijing is also a city with serious water shortages. Calculations show that Beijing’s water resources reserves are 1.827 billion cubic meters, and water resources imported from other places are 1.915 billion cubic meters. The total water resources in Beijing are 3.742 billion cubic meters per year, with per capita water resources of 366.8 cubic meters per year, accounting for only 13.8 of the national average. %, ranking second among the capitals of 120 countries in the world. Since Beijing’s underground water basin is approximately closed, its underground water inflow and outflow is zero. The amount of outbound surface water in Beijing has been observed for many years, accounting for approximately 14.28% of the total annual precipitation, or 1.438 billion cubic meters, with various losses of 332 million cubic meters. Therefore, the actual available water volume in Beijing is only 1.972 billion cubic meters.

In order to alleviate the problem of water shortage in Beijing, some meteorological experts in Beijing participated in a meeting hosted by the Beijing Association for Science and Technology and the Beijing Meteorological Society in 1990 to discuss how to alleviate the problem of water shortage. Experts at the meeting reached consensus and believed that exploring the use of aerial cloud water resources for artificial rainfall enhancement is a new way with low investment and quick results. Since the United States successfully conducted its first artificial precipitation experiment by aircraft in 1946, nearly 100 countries or regions have carried out artificial weather modification experiments. Israel carried out artificial precipitation in the western coastal areas, and after rigorous physical and statistical tests, precipitation increased by 15%. my country's artificial precipitation was first carried out in Jilin Province in 1958. Over the past 30 years, Jilin, Inner Mongolia and other provinces and regions have achieved obvious results. The Gutian Reservoir area in Fujian has been experimenting with artificial rainfall for 12 years, with an average rainfall increase of 23%; in the mountainous area upstream of the Baiyang River Reservoir in Karamay, Xinjiang, workers have continued to increase rainfall and snow for 4 years in winter and 3 summers, making the Baiyang River Reservoir The average annual growth rate is 22.6%.

After experts proposed to the municipal government, the Municipal Party Committee and Municipal Government attached great importance to it and decided to establish the Beijing Weather Modification Leading Group, with an office under the Weather Modification Office responsible for artificial rain enhancement and artificial hail prevention in the city. planning, management, business guidance, operation implementation and scientific research work. At the same time, it is determined that artificial rainfall enhancement will be a long-term strategic task and be carried out on a sustained basis.

Artificial rain enhancement is the use of precipitation weather conditions, that is to say, there are clouds that can rain (clouds below 0℃). Through artificial intervention, the water droplets in the clouds are caused to pass through a catalyst (liquid nitrogen). ) After catalysis, ice crystals appear in liquid water droplets, which rapidly cools down the clouds below 0°C, causing changes in the image state. When water droplets and ice crystals exist, the water vapor pressure on the ice surface is smaller than the water vapor pressure of liquid water droplets. In this way, the water vapor molecules on the surface of liquid water droplets move toward the ice surface and attach to the ice particles, causing the ice particles to continue to grow. , and then turn into small snowflakes. During the settling process, the temperature increases as it falls, and gradually turns into small water droplets. In the natural state, it is difficult for liquid water droplets to turn into ice crystals. Through artificial intervention, they can turn into ice crystals and increase precipitation in the case of natural precipitation.

Beijing is located in the North China Plain, bordering the Bohai Sea to the east, the Taihang Mountains to the west, the Jundu Mountains to the north, and the Hebei Plain to the south. It has a warm temperate semi-humid and semi-arid climate. The average annual precipitation is 400-600 mm. 80% of the annual precipitation is concentrated from June to September, especially from July to August. Therefore, we choose to operate at this time to increase surface runoff and increase water for the two major reservoirs, Guanting and Miyun.

Use of water and current status of water resources

Water is an important resource for human life, especially agriculture, which requires a large amount of water for irrigation. Most of the origins of human civilization are in large river basins. Early cities were generally built near water to solve irrigation, drinking and sewage problems. In human daily life, water plays an indispensable role in drinking, cleaning, washing, etc. Water is also the basic element for the survival of all things. However, with the development of social economy, human demand for water resources continues to increase. Since this century, the world's freshwater consumption has increased eightfold, of which agricultural water has increased sevenfold, urban water has increased 12 times, and industrial water has increased 20 times. Moreover, the world's freshwater consumption is increasing at an annual rate of 5%. Currently, there are about 90 countries in the world, and 40% of the population is experiencing water shortage crisis. 3 billion people lack water and sanitation facilities, and 3 to 4 million people die from water-related diseases every year. By 2025, the water crisis will spread to 48 countries and 3.5 billion people will be trapped by water. The deterioration of ecosystems and destruction of biodiversity caused by water crisis will also seriously threaten human survival. In the past 50 years, there have been 507 conflicts caused by water, 37 of which were violent in nature, and 21 evolved into military conflicts. Experts warn: As water resources become increasingly scarce, the battle for water will intensify. The water crisis has become a worldwide concern.

The World Meteorological Organization pointed out in early 1996 that water shortage is the primary problem faced by cities around the world. It is estimated that by 2050, more than 2/3 of the world's population will live in cities, and 46% of the world's urban population lacks water. It is necessary to balance social and economic issues. The relationship between development and urban freshwater supply management, and the construction of large-scale projects for the storage, transportation and management of water resources. The British "Independent" stated that the world's great rivers are drying up at an alarming rate, causing devastating consequences for humans, animals and the future of the earth. To make matters worse, the 20 longest rivers in the world are blocked by dams. 1/5 of freshwater fish stocks are already or on the verge of extinction. On March 16, 2006, the 4th World Water Resources Forum opened in Mexico. The United Nations said in its World Water Development Report submitted to the General Assembly that we have seriously changed the natural laws of rivers around the world. A study report titled "Comprehensive Assessment of World Freshwater Resources" also from the United Nations said: If people continue to act as unchecked as they are now, the number of water-poor people will likely reach two-thirds in 30 years. According to media reports, 60% of drinking water pipes in cities in some third world countries are severely corroded and a lot of water is lost. A United Nations survey stated that the leakage rate of the water supply pipe network in Manila, the capital of the Philippines, is close to 58% of its total water supply; in Singapore, which has better management measures, there is also a pipe network leakage rate of 8%; the United States and the United Kingdom The leakage rate of national pipeline networks is 12%; the figure in China is 20%. There is no doubt that fresh water should be a scarce resource. However, in a considerable number of countries and people, this concept has not yet truly formed.

With the development of science and technology, people have built water conservancy projects to fight against natural disasters such as waterlogging and floods. As a result, some research fields specifically related to water have been formed, such as hydraulics, hydrology, water treatment, etc., and even the industrial aquaculture industry that relies on water for survival has emerged.

According to the British "Guardian" report on February 15, although 70% of the earth's surface area is water, only 3% is freshwater resources. Among them, only 1% of fresh water can be used by humans. Most of the rest is either frozen in the polar regions of the earth or hidden deep underground and is difficult to mine. Humanity’s demand for water has quadrupled since the 1940s and continues to increase endlessly.

According to statistics, one-fifth of the world's population, or 1.1 billion people, currently do not have access to safe drinking water, and another 2.4 billion people lack good sanitation facilities. It kills 5 million people every year, including a child every 15 seconds.

In the 20th century, half of the world's wetlands were lost forever, while groundwater resources were depleted due to pollution or overexploitation. Water crisis is threatening every country and region in the world. For example, the UK has become the country with the most severe water crisis in Europe.

Industrial production and chemical production use this cheap raw material in large quantities. However, the arbitrary discharge of untreated wastewater will cause water pollution. In order to solve this problem, sewage treatment becomes very necessary. (See water pollution and sewage treatment.)

Ranking of water resources indicators of countries in the world

1. Top 10 water resources

Brazil, Russia, the United States, Indonesia, Canada, China, Bangladesh, India, Venezuela, Colombia

2. Bottom 10 in per capita water resources

Kuwait, Libya, Singapore, Saudi Arabia, Jordan, Yemen* **United States, Israel, Tunisia, Algeria, Burundi,

3. Top 10 water consumers

China, United States, India, Pakistan, Russia, Japan, Uzbekistan, Mexico , Egypt

4. Top 10 per capita water consumption

Turkmenistan, Uzbekistan, Kyrgyzstan, Tajikistan, Azerbaijan, Pakistan, United States, Afghanistan

5. Bottom 10 in per capita annual water consumption

Solomon Islands, Haiti, Congo ***, Equatorial Guinea, Guinea-Bissau, Congo, Burundi, Uganda, Central African Republic, Bay Ning

According to statistics, my country's total water resources are 2.8 trillion cubic meters, ranking sixth in the world. The per capita occupancy is 2,340 cubic meters, which is only 1/4 of the world's per capita occupancy. It ranks 109th in the world and is listed as one of the 13 water-poor countries in the world. Among the more than 640 cities in my country, there are more than 300 cities that are short of water and 108 cities that are seriously short of water.

The Development of Water and Agriculture

3000 BC, China

The oldest known irrigation technology was for rice cultivation. Farmers built paddy fields with dikes on all sides, similar to shallow ponds, and then diverted water from nearby streams for irrigation. This ancient technique is still widely practiced in Southeast Asia, East Asia, and South Asia.

2000 BC, Egypt

The Egyptians invented a method of lifting water from the river. They used a tool called Jumei, which used a horizontal bar to easily lift the bucket from the river. Water lifted from the river is channeled through canals to irrigate farmland. This tangerine is still used in Egypt, India and some other countries.

In 700 BC, Assyria

Sennacherib, the king of Assyria in the ancient East, planted fruit trees, cotton and other rare plants around the capital Nineveh.

To irrigate these plants, he built a 10-kilometer-long canal and a stone trough that diverted water from nearby mountains.

500 AD, Mexico

There were many swamp lakes around the former capital of Mexico, Tenoch Mutlan, and the Aztecs built terraces in the swamp lakes. They spread the fertile soil dug out from the bottom of the lake onto the terraced fields and planted corn. The network of ditches around the fields ensures water for crops, and farmers can also drive boats through the fields.

1870 AD, United States

Agricultural water in the dry Great Plains of the central United States can only rely on groundwater. When settlers who were allocated government-owned land came there, they used the power of windmills to extract groundwater, dug ditches, and introduced the extracted groundwater into farmland for irrigation.

1990 AD, Israel

Water is the basis of survival in desert areas. Drip irrigation is an irrigation method that uses small holes in water pipes to drip water directly into the soil next to the roots of each plant. This method can minimize the loss of irrigation water. Making Israel a country with high water utilization efficiency.

Treatment of drinking water

1. First filtration: water introduced from rivers passes through the filter to remove fish, leaves, garbage, etc.;

2. Adsorption: Add alum to the first filtered water to form a sticky floc. The soil, bacteria and other particles will adhere to the alum flowers, and then the alum flowers will be filtered out by sedimentation;

3 . Second filtration: When the water flows through sand or gravel, algae, bacteria and some chemical components are filtered out (equivalent to current household filtered water dispensers);

4. Chlorination: Add chlorine to the water. Kill remaining organic organisms;

5. Ventilation: Force air into the treated water, drive out chlorine, reduce the smell and taste of the water, and ensure drinking safety;

6. Additional Treatment: Sodium or lime can be added to soften hard water. Some communities add fluoride to prevent chlorine from corroding teeth.

(Household) Wastewater Treatment

1. Preliminary treatment: Wastewater flows through the treatment equipment, and the flow rate slows down to allow large solids to settle. When water passes through the sedimentation tank, smaller particles sink to the bottom to form sludge;

2. Reprocessing: In the trickle filtration system, wastewater is filtered through gravel, and a layer of gravel can also be laid on the surface. Bacterial communities to decompose waste in sewage;

3. Additional treatment: The water is discharged into the open pond, where sunlight and air purify it naturally. After entering the atmosphere, pure water vapor is formed. Chlorine is generally added before the treated water is discharged again.

The role of water on the human body

Water is the source of life. Human need for water is second only to oxygen. If a person does not take in a certain vitamin or mineral, he may be able to live for a few weeks or live with a disease for several years, but if a person does not have water, he can only live for a few days. This shows how important water is to human survival.

The important component of human cells is water, which accounts for 60~70% of adult body weight. So what is the purpose of so much water in the human body?

1. Various human physiological activities require water. For example, water can dissolve various nutrients, and fats and proteins must become colloids suspended in water. The state can be absorbed; water flows continuously between blood vessels and cells, transporting oxygen and nutrients to tissue cells, and then excretes metabolic waste from the body. In short, various metabolic and physiological activities of the human body are inseparable from water.

2. Water plays a certain role in regulating body temperature. When people breathe and sweat, they release some water. For example, in hot seasons, the ambient temperature is often higher than the body temperature. People rely on sweating to evaporate water and take away part of the heat to lower the body temperature and prevent people from heat stroke. When the weather is cold, due to the great potential of water to store heat, the human body will not have significant fluctuations in body temperature due to low external temperatures.

3. Water is also a lubricant in the body. It moisturizes the skin. If your skin is dehydrated, it will become dry and lose elasticity, making your face look older. Some joint capsule fluid and serosal fluid in the body can protect the organs from friction and damage and allow them to rotate flexibly. Tears and saliva are also lubricants for corresponding organs.

4. Water is the cheapest and most powerful healing medicine in the world. The health-care and disease-preventive effects of mineral water and electrolyte water are well known. Mainly because the water contains ingredients that are beneficial to the human body. When you have a cold or fever, drinking more boiled water can help induce sweating, reduce fever, and dilute toxins produced by bacteria in the blood. At the same time, increased urination will help accelerate the excretion of toxins.

5. When there are large-area burns, severe vomiting, diarrhea and other symptoms, and a large amount of water loss in the body, fluids need to be replenished in time to prevent severe dehydration and aggravation of the condition.

Water in the ancient worldview

In the early days of civilization, people began to explore the composition or classification of various things in the world, and water played an important role in this. Water is included in the four elements theory proposed by the ancient West; water is also included in the four elements in Buddhism; in the ancient Chinese Five Elements theory, water represents all liquids, as well as things with flowing, moist, and feminine properties.

Water Worship

In human childhood, water has both nurturing and destructive abilities and an elusive temperament, resulting in feelings of love and fear, which gave rise to water worship. By imbuing water with divine spirituality, we pray that water will bring peace, harvest and happiness to mankind.

The Dragon King in Chinese tradition is the deity of water. There is a Dragon King wherever there is water, and there are Dragon King temples and halls all over the country. Worshiping the Dragon King and praying for rain is a traditional Chinese belief and custom.

The colloquial meaning of water

Describes a person who has no future or is not good enough at what he does.

For example: Why are you so wet? (Why are you so bad?)

Mountains and Flowing Waters

Ancient piano music. During the Warring States Period, there were already circulating stories about high mountains and flowing water, so it is also said that "High Mountains and Flowing Water" was written by Boya. The music score was first seen in the Ming Dynasty's "Magic Secret Music Score (written by Zhu Quan in 1425)". The explanation of the "High Mountain" and "Flowing Water" in this score is: "The two songs "High Mountain" and "Flowing Water" are only one piece. The original intention is to "High mountains" means benevolent people enjoy mountains. Later, it means "flowing water" means "wise people enjoy water". In the Tang Dynasty, it was divided into two parts, not divided into sections. Later, the two famous guqin songs "High Mountain" and "Flowing Water", together with the story of Boya playing the guqin and meeting a close friend, were widely circulated among the people.

"High Mountains and Flowing Waters" is based on "Bo Ya's drum and harp meet a close friend", and there are many musical scores. There are two types of music: Qin music and Zheng music. Both have different names and completely different styles.

With the development of Qin playing art since the Ming and Qing Dynasties, "High Mountain" and "Flowing Water" have undergone great changes. "Legend Secret Music" was originally not divided into sections, but later generations of piano music scores were divided into sections. Among the various musical scores since the Ming and Qing Dynasties, "Liu Shui" adapted by Zhang Kongshan, a qin player of the Sichuan School, included in "Tianwenge Qin Pu" (1876) compiled by Tang Yiming of the Qing Dynasty, is particularly distinctive, with the addition of "roll, whisk, The sixth section, which uses the technique of "chuu and zhu" to create the sound of running water, is also known as "Seventy-two Rolling Flowing Waters". It is widely circulated for its vivid image and blend of scenes. According to research by qinists, before the publication of the "Tianwenge Qinpu", the sixth section of "Liu Shui" played by Zhang Kongshan was not included in any qin score. The whole song only had eight sections, which is consistent with the explanation of the "Magical Secret Music".

There is also a zither piece called "Mountains and Flowing Waters". The music is very different from the zither piece, and it is also based on "Bo Ya's Drum and Gu Qin Meet a Friend". There are scores of various genres available.

The one that is most widely spread and has the greatest influence is Zhejiang