United States: The flow of kitchen and bathroom equipment should be restricted.
100 years ago, Americans consumed an average of 10 gallon of domestic water every day (about 3.8 liters per gallon), but now it is 100 gallon, and the pressure of population growth on water resources is increasing day by day. The average annual household expenditure on water and sewage treatment in the United States is $474, which is the lowest among all developed countries in terms of the proportion of total household income. Among them, American families have contributed to saving water.
There are three main types of household water in the United States, bathroom water, laundry water and kitchen water, of which bathroom and laundry water account for about 2/3. In addition, the leakage waste is serious, accounting for about 14%.
How do families save water? The U.S. Environmental Protection Agency put forward measures to change bad water use habits and use water-saving products, taking into account all aspects of domestic water use. The principles of water saving include: don't let water flow when not in use; If the water pipe system leaks, it should be repaired in time to reduce waste.
The EPA reminds the public not to shave and brush their teeth with the tap on; Try to shorten the shower time; Turn off the tap when soaping and shampooing; Don't treat the toilet as a trash can; When taking a bath, the bathtub is half full. The methods of saving water in the kitchen are: washing fruits and vegetables with pots; Don't thaw food with water; The dishwasher is used at full load, and the water quantity is adjusted according to the load; When washing dishes by hand, rinse with water in the sink. The EPA also pointed out that the washing machine uses the least amount of water when it is fully loaded, and the amount of water should be adjusted according to the number of clothes.
The main types of household water-saving products in America are faucets, shower heads, toilets and washing machines. The United States Congress legislated in 1992 that all toilets sold in the United States must meet the standard that the water consumption at one time should not exceed 1.6 gallon. At present, shower heads made in the United States require that the water flow per minute should not exceed 2.5 gallons. The drum washing machine, which has become very popular in America, is a recommended product for saving water in American household laundry.
The use of low-flow faucets is considered as a very effective water-saving measure, and its purchase and installation costs are not high. 200 1 a survey in Seattle, USA shows that using low-flow faucets can save water 13%.
Germany: The government subsidizes residents to collect rain.
Generally speaking, Germany is rich in water resources and abundant in rain. Protecting water resources from pollution is an important part of German government's environmental protection. At the same time, the government does not forget to encourage the conservation and utilization of water resources in various ways.
Saving water can save the country's expenditure on water supply, reduce the production of wastewater and sewage, and water plants can reduce the supply of tap water. At the same time, the energy consumption of water supply and sewage treatment will also be reduced.
Since the late 1990s, the average daily consumption of tap water in German households has been 1.30 liters. Although the per capita consumption of water resources in Germany is relatively low compared with other industrial countries, the government believes that there is still considerable water-saving potential. According to relevant surveys, in the daily water consumption of Germans, people only need 4 to 6 liters of water for diet, and about two-thirds of the water is used for bathing and flushing toilets.
To this end, the German Ministry of Environment introduced water-saving tips to the public through the Internet and other forms. The government first advocated changing personal water habits. For example, replacing a bathtub with a shower can save up to 70% of water and reduce the energy consumption required to heat water.
In terms of technology, the government advises the public to pay attention to choosing water-saving products when buying toilets and washing machines. Germany has abundant rainfall and great potential for rainwater utilization. Toilet water does not need tap water that meets the drinking standard, so we can consider using reserved rainwater instead. In some states and communities in Germany, local governments provide some subsidies to encourage and help residents to buy rainwater collection equipment. Experts suggest that it is best to water the garden with rainwater. In addition, it is best to water in the morning or evening, not at noon, so as to reduce the loss caused by evaporation.
Adjusting the water price is also an important lever for the German government to save water regularly. In recent ten years, the average water price in Germany has been increasing year by year, but the increase rate has gradually decreased. 1994 The average price of tap water per ton was 1.43 euros, an increase of 8.1%over the previous year; In 2002, the average price of tap water per ton was 1.7 1 euro, only 0.6% higher than that in 2006.
Japan: Biological toilets have no waste water.
The concept of protecting water resources and saving water has been deeply rooted in people's hearts in Japan, and it has already changed from me to practical action in daily life and production activities.
Toilets in Japan pay great attention to saving water. In many places, reclaimed water is used to flush toilets, mostly factory wastewater, for recycling. Reclaimed water can't be drunk directly like tap water, but washing hands in the toilet is not a problem. Most faucets in Japan have automatic sensing devices, which can be extended immediately. Many faucets spray water through many fine holes like shower heads, which can meet the needs of washing water without wasting. At the Aichi World Expo site, the reporter also saw a "biological toilet". There is no waste water in this toilet, and the water used to flush the toilet can be reused after treatment, which can save water 1 1,000 tons during the World Expo. Of course, the cost of toilets like this is very high, and it is difficult to put them into practice now, but at least it reflects the Japanese water-saving consciousness and points out the direction of water-saving in the future.
In family life, Japanese people pay great attention to saving water: for example, after washing vegetables, they should pay attention to turning off the faucet first, and then put the vegetables away, instead of turning off the faucet first; After frying the vegetables, the pan is full of oil, which is very water-consuming. Clean up the oil stain with paper first, and then wash it with water, which can save water and reduce the pollution of water source. At the same time, oil-absorbing paper can be used as combustible garbage, which can increase the recovered heat when burning. In a word, the Japanese have paid attention to saving water from scratch.
Japanese companies are competing to develop water-saving products, such as water-saving dishwashers and water-saving washing machines. Some dishwashers spray dilute water from all angles, and the water consumption is only a few tenths of that of hand washing dishes. The washing machine developed by a company has an inclined plane above the drum, which can save half of the water and is well received by people.
Saving water can reduce family expenses. For example, using a water-saving dishwasher can save more than 20 thousand yen in utilities every year. But the Japanese are not only saving money, but doing their social responsibility. Everyone is a member of society. While meeting personal needs, we should also consider whether it is beneficial to society.
Latin America: legislation to ensure water conservation
The distribution of water resources in Latin American countries is uneven. With the growth of population and the acceleration of industrialization and urbanization, Latin American countries are facing the problems of increasing demand for water resources and increasingly serious water pollution.
In order to protect and make rational use of water resources, Latin American countries have successively formulated and implemented new national water laws, reformed water supply and environmental systems, implemented hierarchical management of water resources, and encouraged private participation in the water market since the 1980s.
By perfecting legislation, the Mexican government has gradually established a unified water resources management system and decentralized management institutions at the state level. All units and individuals that take water, use water and drain water must obtain licenses issued by the state water commission.
Two-thirds of Mexico's land area is in arid or semi-arid state, so it has to exploit groundwater resources to meet the needs of industrial and agricultural production and domestic water. This has led to the rapid decline of groundwater level and the rapid increase of groundwater salinity. In this regard, the Mexican government has continuously improved the water charging system to limit the over-exploitation of groundwater resources.
Chile's national water law stipulates the transfer system of water rights, and the joint-stock system of government and private ownership promotes the formation of water market. The new water rights law, which will be implemented in June 5438+next year 10, also stipulates the protection of rivers and lakes, stipulating that the public works department is in charge of water rights under special circumstances such as drought, so as to ensure the sustainable utilization of water supply facilities and give consideration to social benefits.
In Argentina, for example, except for the capital, the federal government delegated water rights (including irrigation management rights and the right to formulate various water-related policies and regulations) to provincial local governments, and handed over some water supply and sanitation projects to the private sector, so that irrigation associations in the country enjoyed completely legal rights, including taxation rights. At the same time, the Afghan government also encourages water users' associations to unite to form scale development and operation, reduce administrative expenses and improve water supply efficiency.
Colombia's new water law encourages private capital to invest in irrigation and drainage projects and promotes the participation of water users' associations in the construction and management of irrigation and drainage projects. At present, 16 in 24 large and medium-sized irrigation areas in China has been managed by local associations.
India: There is a water storage tank under the overpass.
In India, people began to collect rainwater very early, and there are many rainwater collection devices and water delivery systems, forming a culture with local characteristics.
Many Indians collect rainwater directly from the roof and introduce it into the reservoir in the hospital. After a rainy season, it can meet the drinking water demand for one year. Until now, when farmers in many parts of India build houses, they will build a brick water storage tank in the yard, which is filled with pebbles and coarse sand. The rainwater can be drunk after being simply filtered by sand and stone. The roof has a certain slope, which is convenient for the rain to flow down quickly. There are protruding grooves on the eaves to receive the water flowing down from the roof, and then enter the ground water storage tank through the conduit. The wellhead of the water storage tank is higher than the ground, which avoids the pollution of human and animal feces, and the pool water can meet the drinking needs of people and animals. In the open field of a village, farmers will dig some water storage tanks, the bottom of which is mostly cement masonry structure, which is mainly used for crop irrigation.
In New Delhi and some big cities, overpasses elevated in the air have also come in handy in saving water. The local municipal authorities have built large water storage tanks under many overpasses. When the rainy season comes, rainwater directly enters the pool under the bridge through the drainage ditch along both sides of the overpass to meet the irrigation water demand of urban green space. In some large airports, concrete floors are also convenient for collecting rainwater. In some airports, aqueducts about two feet wide and more than one foot deep are built to guide rainwater into the storage tanks near the airport.
Collecting rainwater has many unique advantages. First of all, there are basically no geographical restrictions, so most parts of India have rainwater collection devices that meet the local regional characteristics. For example, in the south, bamboo is often used as a diversion device for rainwater collection devices. Secondly, it is economical and practical, and the water storage tank can be large or small. Building materials are mainly bricks, cement, sand and stones. And the investment is not big, but it solves the problem of drinking water and irrigation. Third, it won't have a big impact on the environment like building dams and canals.
Most water-saving devices in India can make full use of local water resources. In the desert area in the north, a retired engineer named Nafer also invented an "artificial glacier". He built a ditch first, and then used a short metal pipe to introduce the water from the ditch into the low-lying area of the neighboring village. When water from natural glaciers melts into metal pipes, water freezes. As more water enters, the water will wash the ice out of the pipeline and rush into low-lying areas to form artificial glaciers. Glacier is the only water source in the desert, and Nafer leads the glacier near the village so that the villagers can irrigate it in spring. This kind of artificial glacier has clean water quality and provides a stable water source for local residents.
In some poor and remote areas, the local government has built many rainwater collection facilities for farmers through raising funds from residents, partial government investment and donations from NGOs. The central government of India has also set up a special Ministry of Water Resources to manage and distribute water resources throughout the country.
Israel: Saving water is a must.
60% of Israel's land area is classified as arid area, and water shortage seriously restricts its agricultural development. Since the founding of Israel more than 50 years ago, agricultural output has increased by 12 times, while agricultural water consumption has only increased by 3 times. Using price lever to encourage water saving, developing unconventional water sources and developing water saving technology are the key points of water saving in Israel.
Israel promulgated the water law in 1959, stipulating that all water resources in the territory are owned by the state and distributed by the state, and no unit or individual may exploit groundwater at will. The pricing, distribution and supervision of water resources are the responsibility of special water resources committees.
The Water Resources Committee determines water prices according to water consumption and water quality. The water price used by urban residents is much higher than that used by farmers, and the government also charges urban residents extra sewage treatment fees. Farmers' agricultural production needs a lot of water, so the government has set a ladder price for farmers' water use to encourage water conservation. If the water consumption is lower than the quota, the price will be lower; The more you use, the higher the price. In addition, the price of water obtained from seawater desalination or sewage treatment is relatively cheap to encourage the recovery and reuse of water resources.
Due to the shortage of water resources, Israel has increased the use of unconventional water resources, which is at the forefront of the world. 1972, the Israeli government formulated the "National Sewage Reuse Project", and conducted experimental research on sewage irrigation, which achieved great success.
Israel's vision is that all future agricultural irrigation will use reclaimed water after sewage reprocessing.
Israeli researchers have also developed the technology of "soil aquifer treatment", that is, after sewage treatment, it will be reinjected into the aquifer through soil, and the soil and sand layer will play the role of purification and filtration. Practice has proved that the water treated by this technology is close to the quality of fresh water and can be safely used for agricultural irrigation. This technology has been used in densely populated areas of Israel, and about 654.38 billion tons of pure water can be obtained every year.
Since 1960s, Israel has devoted itself to the research of seawater desalination technology, and the actual output has also increased year by year. According to the prediction of Israel Water Resources Committee, by 2020, Israel's seawater desalination capacity will reach an annual output of 200 million tons of fresh water, accounting for nearly 8% of the total water supply capacity.
Among the water-saving technologies in Israel, agricultural drip irrigation is its masterpiece. Practice has proved that the application of drip irrigation technology has the following advantages: first, water can be directly transported to the roots of crops, so it saves water by 20% compared with sprinkler irrigation; Secondly, the application of drip irrigation on cultivated land with large slope will not aggravate soil erosion; Thirdly, the purified water extracted from saline groundwater or treated sewage with high salt content can be used for drip irrigation without causing soil salinization.
At present, drip irrigation technology adopts automatic valve and computer control technology. Israeli fertilizer manufacturers also try their best to develop water-soluble products, so fertilization can be carried out at the same time as drip irrigation, which not only improves production efficiency, but also saves costs and makes drip irrigation technology more perfect.