I have some data here. Human activities will cause a large number of industrial, agricultural and domestic wastes to be discharged into water bodies and pollute them. At present, more than 420 billion cubic meters of sewage is discharged into rivers, lakes and seas every year, polluting 5.5 trillion cubic meters of fresh water, which is equivalent to more than 14% of the total global runoff.
People's Republic of China (PRC) Water Pollution Prevention Law promulgated by 1984 has a clear definition of "water pollution", that is, the phenomenon that the chemical, physical, biological or radioactive characteristics of a water body are changed due to the intervention of a certain substance, thus affecting the effective use of water, endangering human health or destroying the ecological environment, and causing the deterioration of water quality is called water pollution. Yangcheng Evening News has a specific report.
According to the ninth five-year plan of national environmental protection and the long-term goal of 20 10, the national sewage treatment capacity will increase by 20 million tons/day by 2002. The centralized treatment rate reached 25%. It is estimated that the investment in supporting pipe network of the treatment plant alone will reach 85 billion yuan, and by 20 10, the centralized treatment rate of urban sewage will reach 40%. It is estimated that more than 0/000 urban sewage treatment plants will be built.
According to statistics, 320 million farmers in China have no drinking water; About 65.438+0.9 billion farmers drink polluted water. In addition, the water used to irrigate farmland stinks and some polluted bubbles float. However, the food produced under such conditions has reached the dining table of China people.
There are also many water pollution incidents. From June 5438 to October 30, 2000, a gold mine sewage sedimentation tank in Romania was flooded, and 65438+ 10,000 liters of sewage containing a lot of heavy metals such as cyanide, copper and lead was washed into Tisza River, a tributary of the Danube River, and then quickly merged into the Danube River and spread downstream, resulting in a large number of fish deaths and the river water was undrinkable. Hungary, Yugoslavia and other countries suffered greatly, and their national economy and people's lives were affected to some extent, which seriously damaged the ecological environment of the Danube River basin and triggered international litigation.
1July, 1994, heavy rain suddenly fell in Henan Province in the upper reaches of Huaihe River, and the water level of Yingshang Reservoir rose sharply, exceeding the flood warning line. So the floodgate was opened, and 200 million cubic meters of water accumulated in the upstream was released in one winter and spring. Where the water flows, the river is turbid and the foam on the river surface is dense, killing the fish and shrimp at once. Some local residents in the downstream have symptoms such as nausea, diarrhea and vomiting after drinking the river water that has not reached the drinking standard after being treated by the waterworks. After sampling inspection, it was confirmed that the water quality of upstream water deteriorated, and the waterworks along the Yangtze River was forced to stop water for 54 days. Millions of Huaihe people are in a hurry to drink water, and many places spend a lot of money to get water to drink. Some local residents snapped up mineral water, which was the "Huaihe water pollution incident" that shocked China and foreign countries.
With the industrial progress and social development, water pollution is becoming more and more serious, and it has become the number one environmental control problem in the world.
As early as the18th century, Britain only paid attention to industrial development, but neglected the protection of water resources. A large amount of industrial waste water and residues poured into the river, which caused the pollution of the Thames and basically lost its use value, thus restricting economic development and affecting people's health and survival. After 100 years of treatment, it invested more than 500 million pounds. It was not until the 1970s that the water quality of the Thames was improved.
Who is the source of life? I hope everyone will cherish every drop of water!
Model essay on the topic of "water" in the second college entrance examination composition
Water is the most selfless thing in the world.
Why does the water flow downwards? This is the question I've always wanted to know. Doesn't it know that standing on a high place can see more beautiful scenery? But it doesn't care, it goes its own way and flows downwards, whether it is a mountain or a boulder, it must flow to the lowest place. I think water must want to have those flowers and wait for them to feed. How can water not overcome this difficulty for them?
Water is the most United thing in the world.
From a drop of water to a river, from a river to a river, from a river to a sea, and finally become an endless Wang Yang. Water pierces the stone and chisels the stone wall, never afraid, just to meet their brothers and sisters and walk with them.
Water is the most tolerant thing in the world.
Water embraces everything, big or small, beautiful or ugly. It never dislikes it, even if it is dirty, it is not angry at all.
Water is like a person, it is like a teacher, selfless dedication; It is like a classmate, United as one; It is as helpful as Lei Feng.
Maybe, I don't know water, but I want to be a person like water.
Model essay on "water" in college entrance examination composition
Water is a colorless, odorless and invisible substance.
As we all know, water should be clear and transparent. People see a lot of red and blue water because people add a lot of pigments to the water according to different needs. So colorless is one of the basic properties of water.
If you want to distinguish the same colorless liquor as it, you just need to smell it with your nose. Water is tasteless, while liquor has the unique smell of wine. It can be seen that water has no taste.
Both wood and stone have fixed shapes, which will not change no matter how they are placed, but water is different: put them in a cylindrical container and the water will become cylindrical; In a rectangular container, water becomes rectangular, so water has no fixed form.
Water is the source of life, and all living things are inseparable from water: plants need water for irrigation to thrive, animals and humans need water for life, and even microorganisms need water. Although two-thirds of the earth's area is water, at present, the freshwater resources that are easy to be used by human beings only account for 0.3% of the global freshwater resources, accounting for only 7//kloc-0.0 million of the global total water storage, and the world water resources account for 30% of the global water resources, of which fresh water accounts for 0.73%. With the aggravation of water crisis and the continuous deterioration of water environment quality, water shortage has become one of the most concerned resources and environmental problems in the world. It is even predicted that the cause of future wars is probably the competition for water resources, so we should save water.
As the most precious resource on the earth, we should save water and make rational use of it, and don't let the last drop of water on the earth become our tears!