First, the biological control law ". Cyanobacteria is a kind of food for freshwater fish, which can be used as fry to control algae and prevent algae outbreak. Cyanobacteria itself is a kind of food for freshwater fish. Every 1 kg of silver carp or silver carp can "kill" 40 kg to 50 kg of cyanobacteria. Judging from the released fried fish, silver carp can eat 60 kilograms of cyanobacteria in total. It is estimated that the investment of 1 10,000 yuan in Taihu Lake, worth about 2.8 million crucian carp fry, can effectively control the occurrence of cyanobacteria in Taihu Lake. However, if the water bloom is seriously polluted, fish can't grow and produce a large number of populations, which is an uncontrollable large-scale outbreak of cyanobacteria.
Second, the biological floating bed method. Absorb algae plants and other organisms to control water nutrients and inhibit algae reproduction, thus establishing an ecological balance system. Let water be planted in an artificial floating bed, and aquatic plants such as canna, water hyacinth and dried umbrella grass can be planted artificially, which can inhibit the growth of cyanobacteria regardless of the absorption of nitrogen and phosphorus in the water.
Mechanical fishing. This is the most primitive and traditional way, that is, Wuxi water port, which is related to human algae and fish in the water, adopts this way. In order to improve the speed, an automatic metal film filter was also invented. In the process of slow movement, all cyanobacteria fishing boats are manually rotated thousands of times through metal films. Flocculation, sedimentation, air flotation, plug flow and algae are added in the fishing process. The disadvantage of complete salvage is that the treatment of cyanobacteria is still a large area of hard work.
Fourth, chemical methods. Chemical drugs are generally used to kill, and copper sulfate is generally used. Copper sulfate is also commonly used in early marine red tide control, and the effect is good. The teratogenic effect of cupric ion on the metamorphosis of biological larvae leads to the serious shedding of feed algae. Copper sulfate is toxic and will destroy the normal aquatic ecosystem, so be careful about chemical killing.
Fifth, microorganisms remove algae. Screening and separating activated sludge flora beneficial to bacterial powder, spray drying to obtain high-density patented filler, forming an efficient treatment system, and connecting it to mass production through factories. Some experiments show that in Shanghai, before dark, the river regulation, water eutrophication is serious, and aquatic plants and animals grow in large numbers. After 12 days of treatment, the water quality in the regulation section of Xiachangpu River has been obviously improved, and the water quality is clear and odorless.
Sixth, use the magnetic algaecide with high application and high intensity magnetic field to kill algae. The results showed that the number of algae in the water decreased from 500,000 /ml to 50,000 /mL under the action of a high magnetic water processor with a magnetic field intensity of 3,700 gauss, which eliminated the foundation of cyanobacteria. Dissolved oxygen and transparency in water; From the original 2.40 mg/L and 40 cm to 7.20 mg/L and 75 cm, the water quality has been obviously improved. The disadvantage of this method is high cost and no large-scale cyanobacteria treatment.
The seventh dredging. Imported running water, such as the water from the Yangtze River, used a lot of cyanobacteria water to rush into the stinking lake. What are the characteristics? Blue-green algae have a large range of dominance, but the disadvantage is that it can not fundamentally control pollution and transfer it to other places. It should not be a large-scale proposition.
It should be said that the treatment method is the "last resort", and it is very limited to spend 480 million failed manual control measures to control the pollution in Dianchi Lake. Although beggars, your neighbors, wash the pollution of Taihu Lake and Chaohu Lake with Yangtze River water, they can get temporary relief with one punch. Only when the pollution is transferred to the coastal waters and transformed into brown algae, red tides and cyanobacteria blooms will the pollution be finally controlled. However, scientific control measures should be strengthened, great determination should be made, and powerful measures should be taken to cut off the source and flow of industrial and domestic sewage and farmland nitrogen and phosphorus pollution. Respect for natural selection is the source pollution blocking and ecological self-repair, supplemented by necessary artificial control measures.