Urgent! ! ! Successful examples of water pollution control at home and abroad! !

1. Geneva Lake in Geneva, Switzerland, with beautiful scenery, is the largest inland lake in Europe, but it has also become a dead lake and a smelly lake. In 1970s, Lake Geneva was seriously polluted by industrial, agricultural and domestic wastewater, and the fish in the lake were on the verge of extinction.

In order to improve the water quality, the Swiss government has enacted strict laws to limit the discharge of pollutants and established a sewage treatment plant, even the treated sewage will not be discharged into the lake. Since half of the lake belongs to France, the local government has also established a transnational water pollution control mechanism to promote cooperation between the two countries and jointly deal with the problem of river pollution ... By the beginning of this century, Lake Geneva was completely safe for people to swim, row or dive for boating, and the lake water could be directly drunk.

The experience of harnessing Lake Geneva mainly includes: first, using biochemical technology to transform polluted river water; The second is to raise the awareness of the whole people to protect the lake, so that everyone can realize that every enterprise and everyone has the responsibility to save Lake Geneva, and saving the lake means saving everyone; The third is to formulate strict regulations to strictly distinguish pollutants from non-pollutants. Polluted water is not allowed to flow into Lake Geneva, and the use of pesticides on both sides of the river is restricted. In Geneva,13 parks do not use pesticides.

2. "Upstream pollution." "Downstream disaster" is a very common situation in river management in China. The basin and dynamics of rivers determine that river management has a leap, but the upper reaches of rivers are often economically backward areas. How to carry out cross-border cooperation and joint management, the "compensatory development in different places" model in river basin management in Zhejiang Province gives us a good reference.

"Compensatory development in different places" refers to a mechanism that the investment projects in the upper reaches of the river are introduced into the downstream county (city) development zones, and all the local tax profits generated are returned to the upper reaches. For example, Jinhua City, Zhejiang Province has established a national-level ecological demonstration zone interest compensation mechanism, and established a "Jinpan Poverty Alleviation Economic Development Zone" for Pan 'an County, the water source of Qiantang River, Cao 'e River and Oujiang River. As the production land of Pan 'an County, the source area of the city, all the economic benefits and taxes generated here belong to Pan 'an County. Because of this "enclave", Pan 'an rejected 150 polluting industrial enterprises and closed 37 local enterprises with good benefits but serious pollution, effectively reducing the pollution in the upper reaches of Qiantang River, Caoejiang River and Oujiang River.

In addition, in order to control water pollution in river basins, Zhejiang Province has also adopted the policy of "staying at home and moving out" to achieve "win-win" between protection and development.

After more than ten years' efforts, China scientists have successfully explored ecological management by planting aquatic plants in a lake in the middle reaches of the Yangtze River. This achievement is expected to be applied to a wider range of fields.

The outbreak of cyanobacteria in Taihu Lake earlier this year forced the China government to take more stringent measures to ban the discharge of pollutants into the lake. "Controlling pollution is only the first step," said Yang Hongyuan, a biologist and academician of the Chinese Academy of Sciences. "To restore the ecological function of lakes, we still need to take a long road of ecological management."

Liangzi Lake is recognized as a healthy lake with the best water environment protection and the richest biological species in the middle and lower reaches of the Yangtze River. Since 1992, scientists have planted nearly 200,000 mu of aquatic plants here. Together with the original natural aquatic plants, the coverage rate of aquatic plants accounts for about 80% of the whole lake.

According to the monitoring data of the environmental protection department, the water quality of Liangzi Lake reappears as Class I every year, and the overall water quality remains as Class II, so it can be directly drunk. Many indicators of its ecosystem are in the leading position among the same type of key monitoring lakes in China.

Liangzi Lake, with a water surface area of more than 300 square kilometers, is the second largest lake in Hubei Province, which is located between Wuhan, Huangshi, Ezhou and other cities with dense heavy industry, and has great ecological pressure. From 1992, the Aquatic Plant Laboratory of School of Life Sciences of Wuhan University began to study the orientation of the structure and function of the aquatic ecosystem in Liangzi Lake. In 2005, the Ministry of Science and Technology officially approved the establishment of Liang Zi Lake Ecosystem National Field Scientific Observation and Research Station.

According to Professor Yu Dan, stationmaster of Liangzihu National Station and doctoral supervisor of Wuhan University, aquatic plants and algae are two main plants in the lake. They are interdependent. For example, one kind absorbs more nutrients such as nitrogen and phosphorus, while the other kind absorbs less, and its growth and reproduction are inhibited. Therefore, if aquatic plants are abundant, they will absorb a large number of biogenic elements such as nitrogen and phosphorus in the water body, so that the lake is at a poor or medium nutrition level, algae will not multiply in large numbers, and the water quality is good.

In the past 25 years, the research team led by Professor Yu Dan has collected more than 654.38+0.5 million aquatic plant specimens all over the country, and initially established the aquatic plant germplasm resource bank and database. He said: "planting aquatic plants to prevent lake degradation has less investment and great effect, and there are no technical obstacles."

The governance model of Liangzi Lake has been successfully applied to other areas. From 1999 to 200 1, the blue-green algae bloomed in Changtan Reservoir, a water source in Taizhou City, Zhejiang Province for three consecutive years. In 2002, Yu Dan's research group dispatched grass seeds and propagators from Liangzi Lake, and planted 1 10,000 mu of grassland in the reservoir area, which restored the water quality to Class II. Since 2003, there has been no cyanobacteria bloom.

In recent years, the problem of lake ecological function degradation in China is very prominent. Before the 1970s, almost all lakes in the middle and lower reaches of the Yangtze River were "grass lakes", with lush aquatic plants and strong self-purification ability. Later, due to reclamation, purse seine farming and a large number of industrial and agricultural pollution, aquatic plants in many lakes have become extinct, algae have proliferated and evolved into "algae-type lakes", and the lake area has been decreasing or even dying.

According to the State Environmental Protection Administration, 20 natural lakes die out every year in China, and about 65,438+0,000 inland lakes have decreased in the past 50 years. At present, the number of more than 1 000 lakes in Hubei, a province with thousands of lakes, has dropped sharply to more than 300. However, serious cyanobacteria pollution broke out in key lakes such as Taihu Lake, Chaohu Lake and Dianchi Lake, threatening the drinking water safety of residents.