Water (H2O) is an inorganic substance composed of two elements, hydrogen and oxygen, and is a colorless, odorless, transparent liquid at room temperature and pressure. In nature, pure water is very rare, water is usually mostly a solution of acids, alkalis, salts and other substances, and it is still customary to call this aqueous solution water. Pure water can be obtained by several distillations with platinum or quartz vessels, which, of course, is pure water in a relative sense, and cannot be absolutely free of impurities. Water is a substance that can be transformed between liquid, gaseous and solid states. Water in the solid state is called ice; in the gaseous state it is called water vapor. When the temperature of water vapor is higher than 374.2 degrees Celsius, gaseous water cannot be converted to liquid water by 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, in 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 the largest in the 3.98 ℃, 1 × 103 kg/m3, the temperature is higher than the 3.98 ℃ When the temperature is higher than 3.98 ℃, the density of water decreases with increasing temperature , in 0 ~ 3.98 ℃, water does not obey the law of thermal expansion and contraction, the density increases with the increase in temperature. Water at 0 ℃, the density of 0.99987 × 103 kg/m3, ice at 0 ℃, the density of 0.9167 × 103 kg/m3. so ice can float on the water surface.
The thermal stability of water is very strong, water vapor heated to more than 2000K, there is only a very small amount of dissociation into hydrogen and oxygen, but water will dissociate into hydrogen and water under the condition of electricity. Has a great cohesion and surface tension, in addition to mercury, the surface tension of water is the largest, and can produce more obvious capillary phenomenon and adsorption phenomenon. Pure water has a very weak conductive ability, ordinary water contains a small amount of electrolyte and conductive ability.
Water itself is also a good solvent, most inorganic compounds can be dissolved in water.
At -213.16 degrees Celsius, water molecules are anaerobic.
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 (1 standard atmospheric pressure)
Special Heat : 4.184J/(g.K)
Water cycle
The biosphere can be divided into the hydrosphere, the atmosphere, and the lithosphere. Water circulates in these regions as follows:
1. from the oceans or other bodies of water and also from plants and animals into the air by evaporation;
2. from the sky into the oceans by sinking and from the land runoff into the oceans;
3. most water vapor evaporates from the oceans and returns to the oceans, but winds blow it away across the land and back to the oceans by land runoff, which is about 36 Tt per year. 36 Tt per year. water evaporates from the land 71 Tt per year. 107 Tt of precipitation occurs each year in the following forms: the most common are rainfall, hail, fog, and dew. Concentrated water can reflect sunlight to form rainbows.
The Chinese character for water shuǐ
(Hieroglyphic. Oracle character form. The center looks like a vein of water, and the sides look like flowing water. "Shui is a radical of the Chinese character shui. It is a character derived from water, and denotes either the name of a river or water conservancy, or the flow of water, or the state of water's nature. (original meaning: liquid that falls from the clouds as rain, colorless, odorless, and transparent, forming rivers, lakes, and oceans, with the molecular formula H2O, and is the main component of all living organisms)
1. --Shuowen
Water, quasi-also. Water is the same as water. There is nothing flatter than water under heaven.
The cold air of accumulated yin is water.
The cold air of accumulated Yin is water. Tianwen
Five elements of a water.
The five elements, one of which is water. Hongfan
Wherever water comes out of a plain, it is great water. --Zuo Zhuan? Huan Gongyuan year
Water is said to be cleansing.
The water is said to be cleansed. Qu Li "
Ice, water for the, and cold in the water. -- "Xunzi? Counseling Learning
Liu Yuzhou royal family of the descendants of the world of talent, all the admiration, if the water to the sea. Sima Guang "Ziji Tongjian"
And such as: water choshi (small apparatus for boiling water); water boss (wind storm); water wet (water gas; moisture); water compulsion (dropsy); water Excel (ink stone next to the ink stone used to store water and ink grinding of the small water pellet); water down to the groove (metaphorical heart solid and stable); water spray peach blossom (metaphorical face is good-looking); Mr. Water Mirror (referring to the Three Kingdoms when the Sima Hui, as clear as the water and mirrors); water and land mixed (water and land mixed); water and land mixed (water and land mixed). Water and land mixed (water and land Bi Chen. The water and the sea are all on display); water contour (the contour of the city by the water); water whirlpool (whirlpools in the water); water pavilion (the pavilion or post station near the water)
2.specifically refers to the river [river]
In the water of the river.
3. Qin Feng? Reed reed "
Going to the mouth of the river to guard the empty boat, around the boat moonlight river water cold. Bai Juyi "pipa line (and the preface)"
Also: water (ferry); water branch (river tributaries); water records (books on the river water system); water ultimatum (refers to the documentation of the river water system); water valley (mountain gorges); water tail (the end of the river); water rats (specializing in the theft of thieves in the boat); water (on the water conservancy of the river); water banned (about the river side of the ban); water would be (river confluence)
3. all waters [waters]
Water House is deep, the widow is obscure, the husband is not far away from thousands of miles, will there be for? Li Chaowei Liu Yi biography
Liu Bei, Zhou Yu land and water.
Liu Bei and Zhou Yu were on land and water. Sima Guang "Ziji Tongjian"
And such as: water and land (Buddhism in the land and water dojo); water pool (lake); water residence (living in the water village); water god (water ditch); water king (the sea's alias); water uncle (the legendary god of the water; big river); water sleep (water on the water overnight; water lodging); water veins (waterway, the underground ambient); water scribbling (due to excessive rainfall in the field of the water or the flow of the ground)
We are not sure if we should be able to do this. )
4. A generic term for juice or liquid [liquid].
E.g.: water gift (fruit bait and other gifts); fruit candy (mixed with fruit juice made of candy); ink; saliva; tears; potion; soda
5. big water; flood [flood]
There are nine years of water Yao Yu, seven years of drought Tang. Chao Qiu "on the precious corn dredge"
Said: heaven and earth have law? --Qing? Hongliangji "rule of peace chapter"
And such as: water preparation (facilities to prevent flooding); water city wall (flood walls)
5. star name [morning star].
such as: water host (constellation name. The ancient astronomer's general name for the seven northern stars)
6.official's name].
e.g. Shui Yu (ancient official's name. In charge of the government order of Sichuan and Ze); water official (in charge of water management, fish tax collection official)
7. Silver content in currency. Silver content in coins].
such as: water; buckle water; water; water; water silk (color inferior silver)
8. one of the five elements [water, one of the five elements]
five elements: one said water, two said fire, three said wood, four said gold, five said earth. Hongfan"
9. water animal or plant].
such as: can not afford to buy land chat planting water, recently the lake also collects rent
10. The old refers to the nuns and prostitutes of the painful life situation [deep distress].
E.g.: water bureau (old refers to brothels and prostitutes); water guest (running dock merchants, also refers to human traffickers)
11. additional income or surcharge.
And "hair water" is "hair wealth" [extra income]
12. refers to the water troops [troops fight on the waters]
The people who see the book of fuck say The water steps eight hundred thousand and each fear to deter. --Song? Sima Guang, "Ziji Tongjian"
13.Shui nationality]. One of China's ethnic minorities, living in Guizhou province
14. last name
15. five strokes split into II
Origin of water
Earth is the only one of the eight planets in our solar system that is covered by liquid water. The origin of water on Earth is highly divided academically, and there are currently dozens of different doctrines of water formation. There are views that in the early stage of the formation of the Earth, the original atmospheric hydrogen, oxidation synthesis of water, water vapor gradually condensed down and formed the oceans; there are also views that the formation of the Earth's nebulae in the original existence of water components. There is also the view that water was originally present in the nebulae that formed the Earth. There is also the view that silicate and other substances in the primitive crust reacted under the influence of volcanoes and precipitated water. It has also been suggested that comets and meteorites attracted to the Earth are the main source of water on the planet, and that even now the water on the planet continues to grow.
Impact on Climate
Water has a moderating effect on climate. Water vapor in the atmosphere blocks up to 60% of the Earth's radiation, protecting the planet from cooling. Oceans and land bodies of water absorb and accumulate heat in the summer to keep temperatures from getting too high, and slowly release heat in the winter to keep temperatures from getting too low.
Water in the oceans and on the land surface evaporates into the sky to form clouds, where it falls through precipitation to become rain, and in winter to become snow. The water that falls on the surface seeps into the ground to form groundwater; the groundwater emerges from the earth's layers to form springs, which flow into the sea through streams and rivers. A water cycle is formed.
Precipitation activities such as rain and snow have an important impact on climate. In temperate monsoon climates, the monsoons bring an abundance of moisture, creating distinct wet and dry seasons.
In addition, in nature, water appears and influences the climate and human activities in the form of hail, fog, dew and frost due to different climatic conditions.
Impact on Geography
Seventy-one percent of the Earth's surface is covered by water, making it a blue planet when viewed from the air. Water erodes rocky soil, silts rivers, carries sediment, creates plains, and changes the shape of the surface.
The Earth's surface waters make up the hydrosphere, which includes oceans, rivers, lakes, swamps, glaciers, snow, groundwater and atmospheric water. Because the water injected into the oceans carries a certain amount of salt, and because of the accumulation and evaporation effects over the years, the water in the sea and the oceans is salty and cannot be consumed directly. The water in certain lakes is also saline. The largest body of water in the world is the Pacific Ocean. The Great Lakes in North America are the largest freshwater system. The Caspian Sea in Eurasia is the largest saltwater lake.
The volume of water on Earth is about 1 360 000 000 cubic kilometers. Of this,
the oceans account for 1,320,000,000 cubic kilometers (or 97.2%).
Glaciers and ice caps account for 25,000,000,000 cubic kilometers (or 1.8%).
Groundwater accounted for 13,000,000 cubic kilometers (or 0.9 percent).
Fresh water in lakes, inland seas, and rivers accounted for 250,000,000 cubic kilometers (or 0.02%).
Water vapor in the atmosphere accounted for 13,000 cubic kilometers (or 0.001%) at any known time.
Effects on life
Life on Earth first appeared in water. Water is an essential component of all living organisms. The human body is 70% water; and jellyfish are 98% water. A large number of aquatic organisms, such as aquatic vegetation, live in water.
Water facilitates chemical reactions in the body and also plays a role in the transportation of substances in living organisms. Water plays a great role in maintaining the stability of the temperature of the organism.
Types of water
Different disciplines have some different names for water:
Based on the quality of water, it can be divided into:
Soft water: water with a hardness of less than 8 degrees is soft water.
Hard water: water with a hardness higher than 8 degrees is hard water. Hard water affects the effectiveness of detergents, and hard water heated will have more scale.
Drinking water can be divided into:
Fresh water
Saline water
Additionally there are:
Biological water: water in different states of existence in a variety of living systems.
Natural water:
Soil water: water stored within the soil
Groundwater: water stored underground
Ultra-pure water: water of very high purity, mostly used in the integrated circuit industry
Water of crystallization: also known as hydrated water. In the crystalline material, with chemical bonding forces and ions or molecules combined, a certain number of water molecules.
Heavy water chemical molecular formula for D2O, each heavy water molecule consists of two deuterium atoms and an oxygen atom. Heavy water accounts for less than two-tenths of one percent of natural water, and heavy water obtained through electrolysis is more expensive than gold. Heavy water can be used as a decelerator and heat-carrying agent in atomic reactors.
Super heavy water has the chemical formula T2O, and each heavy water molecule consists of two tritium atoms and one oxygen atom. Superheavy water is extremely rare in natural water, with a ratio of less than one part per billion. The cost of producing superheavy water is tens of thousands of times higher than that of heavy water.
Deuterated water chemical formula for HDO, each molecule contains a hydrogen atom, a deuterium atom and an oxygen atom. It is not very useful.
In addition, water includes sweat, salt water, urine, and distilled water.
Chemical reactions associated with water
Ionization of water and solution pH
Water is an extremely weak electrolyte that weakly ionizes: H2O + H2O?H3O++OH- Usually H3O+ is abbreviated as H+
Ionic product of water Kw=[H+][OH-]
Water is 25 degrees Celsius, Kw=1×10- 14
pH=-log10([H+])
pH<7, solution is acidic, pH=7, solution is neutral, pH>7, solution is basic.
Acidic or basic oxides that are soluble in water can react with water to form the corresponding oxygenated acid or base. The acid and base undergo a neutralization reaction to form salt and water. Water can decompose into hydrogen and oxygen under the action of electric current. Alkali metals burn when they come in contact with water.
In the presence of a catalyst, inorganic and organic substances can undergo hydrolysis with water:
Hydrolysis of organic substances: some atom or group of atoms in the molecule of an organic substance is replaced by a hydrogen atom or hydroxyl group (-OH) of a water molecule, e.g., the hydrolysis of methyl acetate:
Hydrolysis of inorganic substances: this is usually the hydrolysis of a salt, e.g., the weak acid salt sodium acetate binds to H+ in water to form a weak acid, giving a solution that is weak. into a weak acid, making the solution alkaline:
In addition, water itself can act as a catalyst.
Freshwater Shortage and Countermeasures
The total water reserves of the earth are about 1.36x1018m3, but excluding the oceans and other brackish water resources, only 2.5% of it is freshwater. Freshwater and mainly in the situation of glaciers and deep groundwater, freshwater in rivers and lakes only accounted for 0.3% of the world's total freshwater.
The World Meteorological Organization pointed out in early 1996 that water scarcity is the primary problem facing cities around the world, and it is estimated that by 2050, 46% of the world's urban population will suffer from water scarcity. For regions with scarce water resources, water has gone beyond being a resource for living and has become a strategic resource, and because of its scarcity, the likelihood of water wars breaking out is becoming higher and higher.
In order to make the whole world concerned about the shortage of fresh water resources, the 47th United Nations General Assembly set March 22 as World Water Day every year.
Beijing's water situation
Beijing is also a city with a serious water shortage. Calculations show that Beijing's water resources reserves of 1.827 billion cubic meters, 1.915 billion cubic meters of inbound water resources from abroad, totaling Beijing's water resources for the year 3.742 billion cubic meters, per capita possession of 366.8 cubic meters / year, accounting for only 13.8% of the national average, in the world's capitals of the 120 countries ranked after 100. As Beijing's underground is close to a closed basin, the amount of underground water leaving and entering the country is zero. Beijing surface water out of the water observed over the years accounted for about 14.28% of the total annual precipitation, that is, 1.438 billion cubic meters, all kinds of loss of 332 million cubic meters, so Beijing water resources for the actual availability of water is only 1.972 billion cubic meters.
In order to alleviate the contradiction of Beijing's water shortage, in 1990, some of the meteorological experts in Beijing participated in a meeting held under the auspices of the Beijing Municipal Association for Science and Technology and the Beijing Meteorological Society to discuss how to alleviate the problem of insufficient water resources. Experts at the meeting reached *** knowledge, that the exploration of the use of air cloud water resources for artificial rain, is not a small investment, quick results of the new way. Because from the United States in 1946, the first successful aircraft artificial precipitation experiments, nearly 100 countries or regions to carry out experiments in artificial weather. Israel in the western coastal areas of artificial precipitation, by strict physical statistics test, increase precipitation by 15%. China's artificial precipitation since 1958, first in Jilin Province, 30 years, Jilin, Inner Mongolia and other provinces and regions have achieved significant results. Fujian Gutian Reservoir area adhere to the artificial rainfall test 12 years, an average of 23% increase in rainfall; Xinjiang Karamay's Baiyanghe Reservoir upstream mountainous areas for four consecutive winters, three summers of workers to increase the rain, snow, so that the Baiyanghe Reservoir's reservoir volume of an average annual increase of 22.6%.
After the experts' initiative to the municipal government, the municipal party committee and the municipal government attached great importance to the decision to set up the Beijing Municipal Leading Group of Artificial Weather Influence, and set up the Artificial Weather Influence Office under the office organization, which was responsible for the planning, management, business guidance, operation and implementation of the city's artificial rain, artificial hail, and scientific research, and at the same time, determined that the artificial rain should be carried out as a long-term strategic task, and carried out in a sustained manner.
Artificial rain is the use of precipitation weather conditions, that is to say, there can be rain clouds (below 0 ℃ clouds), through artificial intervention, so that the water droplets inside the cloud catalyzed by the catalyst (liquid nitrogen), prompting the liquid droplets appear Ice crystals, so that below 0 ℃ cloud local rapid cooling, causing changes in the elephant state. In the case of water droplets and ice crystals **** exist, the water vapor pressure of the ice surface than the liquid water droplets of water vapor pressure is small, so that the liquid water droplets of the surface of the water vapor molecules to the ice surface movement, attached to the ice particles, so that the ice particles continue to grow up, and then become a small snowflake exist焉, the more the temperature of the fall in the process of settling, and gradually turned into small droplets of water. In the natural state, liquid water droplets are difficult to become ice crystals , through artificial intervention to make it matter into ice crystals, in the case of natural precipitation to increase precipitation.
Beijing is located in the North China Plain, east of the Bohai Sea, west of the Taihang Mountains remnants, north of the Jundu Mountain Range, south of the border with the Hebei Plain, is a warm temperate semi-humid semi-arid climate. The average precipitation over the years is 400-600 millimeters. 80% of the year's precipitation is concentrated in June-September, especially in July-August, so choose to work at this time to increase surface runoff, play a role for the Guanting and Miyun two large reservoirs to increase water.
Water use and the current state of water resources
Water is an important resource for human life, especially in agriculture, which requires a lot of water for irrigation, and most of the origins of human civilization are in large river basins. Early cities were generally established near water to solve the problems of irrigation, drinking and sewage. In human daily life, water plays an indispensable role in drinking, cleaning and washing. Water is also the basic element on which everything depends for survival. However, with the development of society and economy, human demand for water resources is increasing. Since the beginning of this century, the world's fresh water consumption has increased by 8 times, of which agricultural water consumption has increased by 7 times, urban water consumption has increased by 12 times, industrial water consumption has increased by 20 times, and the world's fresh water consumption is increasing by 5% per year. Currently there are about 90 countries in the world where 40% of the population suffers from water scarcity, 3 billion people lack access to water sanitation, and 3 to 4 million people die each year from water-related diseases. By 2025, the water crisis will have spread to 48 countries, with 3.5 billion people suffering from water stress. The deterioration of ecosystems and the destruction of biodiversity brought about by the water crisis will also seriously threaten human survival. Over the past 50 years, there have been 507 water-related conflicts***, 37 of which were violent and 21 of which turned into military conflicts. Experts warn that the battle for water will intensify as water resources become increasingly scarce. The crisis in water resources has become a worldwide concern. The World Meteorological Organization (WMO) pointed out in early 1996 that water scarcity is the primary problem facing cities around the world, and it is estimated that by 2050, more than 2/3 of the world's population will be living in cities, while 46% of the world's urban population suffers from a lack of water, and that it is necessary to balance the relationship between socio-economic development and management of the city's freshwater supply, and to carry out large-scale construction projects for water resource storage, delivery and management. According to the British newspaper The Independent, the world's great rivers are drying up at a worrying rate, with devastating consequences for people, animals and the future of the planet. To add insult to injury, the world's 20 longest rivers are dammed. 1/5 of freshwater fish stocks are already extinct or on the brink of extinction. On March 16, 2006, the Fourth World Water Forum opened in Mexico. In its World Water Development Report to the General Assembly, the United Nations said that we have seriously altered the natural order of the world's rivers. And also from the United Nations, a study called "Integrated Assessment of the World's Freshwater Resources" said: If people continue to be as uncontrolled as now, 30 years later, the number of water-poor people will probably reach 2/3. According to media reports, some third world countries in the city of 60% of the drinking water pipeline erosion is serious, the loss of many water. water. According to a United Nations survey, the leakage of the water supply network in Manila, the capital of the Philippines, is close to 58% of its total water supply; in Singapore, where management measures are better, there is also a leakage rate of 8%; the leakage rate of the network in the U.S. and the U.K. is 12%; and in China, the figure is 20%. There is no doubt that fresh water should be a scarce resource, but in a significant number of countries and populations, this concept has not yet been truly formed.
With the development of science and technology, people build water conservancy, waterlogging and floods and other natural disasters. Therefore, the formation of a number of specialized water-related research areas, such as hydraulics, hydrological sciences, water treatment, and so on, and even produced a water-based industry aquaculture industry.
According to the British newspaper The Guardian reported on February 15, although 70% of the Earth's surface area is water, however, only 3% is freshwater resources. Of this, only 1% of freshwater is available to humans, and most of the rest is either frozen in the Earth's polar regions or hidden deep underground, making it difficult to mine. Human 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. This kills 5 million people every year, including one child every 15 seconds.
In the 20th century, half of the world's wetlands were lost forever, while groundwater resources were depleted by pollution or over-exploitation. The water crisis is threatening every country and region of the world. For example, Britain has become the country with the worst water crisis in Europe.
Industrial and chemical production make heavy use of this cheap raw material. But the arbitrary discharge of untreated wastewater causes water pollution. In order to solve this problem, sewage treatment becomes necessary. (See water pollution and sewage treatment.)
Ranking of water resources indicators for countries in the world
1 . Top 10 water resources
Brazil, Russia, United States, Indonesia, Canada, China, Bangladesh, India, Venezuela, Colombia
2 . Bottom 10 water resources per capita
Kuwait, Libya, Singapore, Saudi Arabia, Jordan, Yemen*** and the State of Israel, Tunisia, Algeria, Burundi,
3 . Top 10 Water Consumption
China, United States, India, Pakistan, Russia, Japan, Uzbekistan, Mexico, Egypt
4 . Top 10 per capita water use
Turkmenistan, Uzbekistan, Kyrgyzstan, Tajikistan, Azerbaijan, Pakistan, United States, Afghanistan
5 . Per capita annual water consumption of the bottom 10
Solomon Islands, Haiti, Congo*** and the country, Equatorial Guinea, Guinea-Bissau, Congo, Burundi, Uganda, Central Africa*** and the country, Benin
According to the statistics, the total amount of water resources in our country is 2.8 trillion cubic meters, which is the sixth largest in the world. Per capita possession of 2,340 cubic meters, only 1/4 of the world's per capita possession, ranked 109th in the world, listed as one of the world's 13 water-poor countries. China's more than 640 cities, more than 300 water-scarce cities, 108 cities with severe water shortages.
Water and the development of agriculture
3000 BC, China
The oldest known irrigation technology was used for rice cultivation. Farmers constructed rice fields with embankments on all sides, similar to shallow ponds, and then drew water from nearby streams for irrigation. This ancient technique is still widely practiced in Southeast, East and South Asia.
Egypt, 2000 BC
The Egyptians invented a method of lifting water from rivers. They used a tool called an orange pulley, which is a crossbar that was used to easily lift buckets of water from the river. The water lifted from the river was passed through canals to irrigate farmland. This type of orange water pulley is still in use in Egypt, India and some other countries.
Assyria, 700 B.C.
Sennacherib, king of Assyria in the ancient East, surrounded the capital city of Nineveh with fruit trees, cotton and other rare plants. To irrigate these plants, he built a 10-kilometer-long canal and a stone flume to draw water from the nearby mountains.
Mexico, 500 A.D.
There were many swampy lakes around the city of Tenochtimutlan, the former capital of Mexico, in which the Aztecs built tablelands. They spread fertile soil dug out from the bottom of the lakes on the terraces and planted them with corn. A network of ditches around the terraces ensured water for the crops, and farmers were able to navigate the terraces in small boats.
The United States in 1870
The parched Great Plains of the central United States relied on groundwater for agricultural water. When settler immigrants, who had been given a share of the government's public land, arrived, they used the power of windmills to extract groundwater, then dug ditches to bring the extracted groundwater into the farmland for irrigation.
Israel, 1990 A.D.
Water is essential for survival in desert regions. Drip irrigation is a method of irrigation that involves drilling small holes in a water pipeline and allowing water to drip directly into the soil next to the roots of each plant. This method minimizes the amount of water lost to irrigation. It has made Israel a country with a high rate of water utilization.
Treatment of Drinking Water
1. First Filtration: the flow of water from rivers, etc., is passed through a screen to filter out fish, leaves, garbage, etc.
2. Adsorption: alum is added to the first filtered water to form a sticky floc, to which soil, bacteria and other particles adhere, and which is then filtered out by sedimentation.
3. Second Filtration: when the water flows over sand or gravel, the water is filtered out by sedimentation. Second filtration: when the water flows through the sand or gravel, algae, bacteria and some chemical components are filtered out (equivalent to the current household filter water dispenser);
4. Chlorination: chlorine is added to the water to kill the remaining organic organisms;
5. Ventilation: to force the air into the treated water, to drive out the chlorine, to reduce the smell and taste of the water, to ensure that it is safe to drink;
6. Additional treatment: sodium or lime can be added to soften the hard water. or lime to soften hard water. Some communities add fluoride to prevent chlorine from corroding teeth.
(Family) Wastewater Treatment
1. Initial Treatment: Wastewater flows through the treatment equipment, the flow rate is slowed down, so that large solids precipitate. When the water passes through the sedimentation tank, smaller particles sink to the bottom and form sludge;
2. Reprocessing: in the drip filtration system, the wastewater is filtered through the gravel, which can also be covered with a layer of bacterial communities to decompose wastewater wastes;
3. Additional treatment: the water is discharged into the open pond, sunlight, air to make it naturally purified. It enters the atmosphere and forms pure water vapor. Chlorine is usually added before the treated water is discharged again.
The role of water in the human body
Water is the source of life. A person's need for water is second only to oxygen. If a person does not intake of a certain vitamin or mineral, may still be able to live a few weeks following the performance or live with the disease for a number of years, but people without water, but only a few days to live. This shows how important water is to human survival.
The important component of human cells is water, water accounts for 60 to 70% of the adult body weight. So what is the role of the human body to so much water?
1. A variety of physiological activities require water, such as water can dissolve a variety of nutrients, fats and proteins, etc. to become suspended in the water in the colloidal state in order to be absorbed; water in the blood vessels, between the cell stream, the oxygen and nutrients transported to the tissues and cells, and then metabolic wastes discharged, in short, a variety of metabolic and physiological activities can not be separated from the water.
2. Water has a role in thermoregulation. When people breathe and sweat will be discharged some water. For example, in the hot season, the ambient temperature is often higher than the body temperature, people rely on sweating, so that the water evaporates to take away some of the heat, to reduce body temperature, so that people from heat stroke. And in the cold, because the water storage heat potential is very large, the human body is not due to the external temperature is low and make the body temperature fluctuations.
3. Water is also a lubricant in the body. It can moisturize the skin. Skin dehydration, it will become dry and lose elasticity, look old. Some of the body's joint capsule fluid, plasma membrane fluid can make the organs free from friction between the damage, and can turn flexible. Tears and saliva are also lubricants for the corresponding organs.
4. Water is the world's cheapest and most therapeutic power of the miracle drug. Mineral water and electrolyte water health and disease prevention is well known. Mainly because the water contains components that are beneficial to the human body. When a cold, fever, drink more boiled water can help sweat, fever, flush the blood bacteria produced by the toxins; at the same time, the urine increased, is conducive to accelerate the discharge of toxins.
5. Large burns and the occurrence of severe vomiting and diarrhea and other symptoms, a large loss of water in the body, are required to replenish fluids in a timely manner to prevent severe dehydration, aggravate the condition.
Water in Ancient Worldview
In the early days of civilization, people began to explore the composition or classification of various things in the world, in which water played an important role. Water was included in the four elements proposed by the ancient West; it was also included in the Four Great Elements in Buddhism; and in the ancient Chinese doctrine of the Five Elements, water represented all liquids, as well as things with a flowing, wetting, and yin and soft nature.
Water Worship
In the childhood of human beings, water has both nurturing and destructive power, inscrutable temperament, and generated feelings of love and fear, resulting in water worship. By endowing water with the spirituality of a god, they prayed for it to bring peace, harvest and happiness to mankind.
The traditional Chinese dragon king is the deification of water. Wherever there is a water source, there is a dragon king, and dragon king temples and halls are found all over the country. Sacrificing to the Dragon King to pray for rain is a traditional Chinese custom of faith.
Colloquialization of water
Describes a person as unproductive or not doing enough.
For example: Why are you so watery that. (Why are you so bad that.)
Gao Shan Liu Shui
Ancient zither music. In the Warring States period, there were already stories about the music of "High Mountains and Flowing Water", so it was also rumored that "High Mountains and Flowing Water" was composed by Boya. The earliest sheet music was found in the Ming Dynasty's Miraculous Mysteries (Zhu Quan wrote the book in 1425), and the explanation of this sheet music's "High Mountains" and "Flowing Water" has the following caption: "The two pieces of "High Mountains" and "Flowing Water" are only one piece of music in the first place. The first one is about high mountains, which means that the benevolent people are happy with the mountains. Later, it was about flowing water, which means that the wise man is happy with the water. To Tang is divided into two songs, not divided into segments. To come, it was divided into four segments for high mountains and eight segments for flowing water." For more than 2,000 years, the two famous guqin tunes, "High Mountains" and "Flowing Water", together with the story of Boya's encounter with his soulmate by drumming the qin, have been widely circulated among the people.
"High Mountains and Flowing Water" is based on the story of "Bo Ya's encounter with his soulmate", and has a variety of scores. There are two kinds of music: zither music and zheng music, both of which have the same name and different styles.
With the development of qin performance art since the Ming and Qing Dynasties, "Gao Shan" and "Liu Shui" have changed a lot. The Secret Record of the Legend is not segmented, while the later zither scores are mostly segmented. Since the Ming and Qing dynasties, a variety of music scores in the Qing Dynasty Tang Yiming edited "Tianwenge music score" (1876) in the collection of the Sichuan School of qin Zhang Kongshan adapted the "running water" is particularly distinctive, adding a "roll, whisking, nicked, note" technique for the sound of running water in the sixth paragraph, also known as "seventy-two roll whisking running water It is also known as "72 Rolls and Flowing Water", and has been popularized for its distinctive image and scenario. According to zither experts, in the "Tianwenge zither sheet music" before the introduction of all the zither sheet music in the "flowing water" are not Zhang Kongshan played the sixth paragraph, the whole song only eight paragraphs, and the "magical secret score" solution to the title of the said in line.