Method for treating water body pollution by utilizing algae-eating worms

Abstract

The invention relates to the technical field of water body pollution treatment and ecological restoration, in particular to a method for treating water body pollution by utilizing algae-eating worms, and the method comprises the following steps: S1, obtaining an algae-eating worm seed source: collecting the algae-eating worms from a natural water body, standing for cultivation, and filtering out the algae-eating worm seed source; s2, expanding culture and domestication of algae-eating insects: performing expanding culture, screening and domestication on the filtered algae-eating insect provenance; s3, putting algae-eating insects: putting the domesticated algae-eating insects into the water body needing to be treated. The method promotes the restoration of the ecological balance of the water body, has the advantages of simplicity and convenience in operation, eco-friendliness, high efficiency, stability and the like, and provides a scientific and effective technical scheme for the treatment of eutrophication of the water body.

Description

Technical Field

[0001] The invention relates to the technical field of water pollution control and ecological restoration, and in particular to a method for controlling water pollution by utilizing algae-eating insects. Background Art

[0002] Water bodies are an important part of the ecosystem, and their health and ecological functions directly affect biodiversity and the quality of human life. With the intensification of human activities, a large amount of industrial wastewater, domestic sewage and agricultural runoff enter the water body, resulting in an increase in the concentration of nutrients such as nitrogen and phosphorus, causing eutrophication. Eutrophication can lead to abnormal proliferation of blue-green algae (such as Microcystis and Anabaena), forming algal blooms and destroying the ecological balance of water bodies. Algal blooms not only turn the water color green or black and reduce transparency, but also release algal toxins, causing the death of a large number of fish and other aquatic organisms, and further leading to a series of ecological disasters such as odor and oxygen depletion in the water.

[0003] Commonly used methods for eutrophication control include biological, physical and chemical methods. Physical methods mainly rely on salvage, aeration and other means to directly remove algae, but these methods can usually only solve short-term problems and are difficult to eradicate the source of nutrients in the water. Chemical methods use chemical agents (such as copper sulfate, flocculants, etc.) to kill algae. Although the effect is fast, it is easy to cause secondary pollution to the water body and pose a potential threat to aquatic life and human health.

[0004] In recent years, biological treatment technology has gradually attracted attention due to its low cost, high efficiency and environmental protection. For example, by releasing filter-feeding fish (such as grass carp and silver carp) or algae antagonistic microorganisms (such as Bacillus and Pseudomonas), the growth of blue-green algae can be inhibited to a certain extent. However, these biological methods also have limitations. For example, filter-feeding fish have low selectivity for blue-green algae and are easily affected by the water environment (such as temperature and dissolved oxygen); algae antagonistic microorganisms need to be effective under more specific conditions.

[0005] Daphnia is a kind of zooplankton widely distributed in freshwater. It belongs to the cladoceran class and is an important component of the ecosystem. As a filter-feeding zooplankton, daphnia can efficiently feed on a variety of algae including cyanobacteria. Its filter feeding efficiency and selectivity give it a significant advantage in controlling the density of cyanobacteria. Studies have shown that daphnia are particularly effective in removing small cyanobacteria in water bodies.

[0006] However, the application of algae-eating worms still faces some technical difficulties: 1. Environmental adaptability: The survival and feeding efficiency of algae-eating worms are affected by factors such as dissolved oxygen, temperature and nutrient concentration of the water body. In a high ammonia nitrogen and high phosphorus environment, the control effect of algae-eating worms is significantly reduced; 2. Population management: In natural water bodies, how to ensure the stability and sustainability of algae-eating worm populations is still a technical bottleneck; 3. Large-scale application: For different water types and pollution levels, how to optimize the release strategy and monitor the effects is the focus of current research. Summary of the invention

[0007] The purpose of the present invention is to provide a method for treating water pollution using algae-eating worms in order to address the problems of low survival rate, insufficient adaptability and limited treatment effect of algae-eating worms in the prior art. By screening algae-eating worm varieties with strong adaptability and high filtration efficiency, and combining optimized cultivation, domestication and release strategies, blue-green algae can be quickly removed from various types of eutrophic water bodies, the transparency of the water body can be improved, and the accumulation of nutrients such as nitrogen and phosphorus can be reduced, thereby promoting the restoration of the ecological balance of the water body. The method has the advantages of simple operation, eco-friendliness, high efficiency and stability, and provides a scientific and effective technical solution for the treatment of eutrophication of water bodies.

[0008] In order to achieve the above object, the present invention provides a method for treating water pollution by using algae-eating insects, the method comprising the following steps: S1: Obtaining algae-eating insect seed sources: Collect algae-eating insects from natural water bodies, place them in a static state for cultivation, and filter out the algae-eating insect seed sources; S2: Cultivate and domesticate algae-eating insects: Cultivate, screen and domesticate the filtered algae-eating insect seed sources; S3: Release algae-eating insects: Release the domesticated algae-eating insects into the water body that needs to be treated.

[0009] Preferably, in S1, the natural water bodies include rivers, lakes, reservoirs and ponds.

[0010] Preferably, in S1, the conditions for static cultivation include: the cultivation water is natural water, the temperature is 20-25°C, the light intensity is 2000-3000 lux, the lighting time is 10-12 h / day, and the time is 5-7 days.

[0011] Preferably, in S2, the conditions for the expansion culture include: introducing the filtered algae-eating worm seed source into the culture water body, the temperature is 20-25°C, the light intensity is 2000-3000 lux, the lighting time is 10-12 h / day, and the culture time is 5-7 days.

[0012] Preferably, the cultivation water contains nutrients and has a pH of 7.0-8.5.

[0013] Preferably, the nutritional ingredients are selected from one or two or more of yeast powder, milk and bacterial agent.

[0014] More preferably, the bacterial agent contains one or two or more of Bacillus licheniformis, Bacillus subtilis and Bacillus cereus.

[0015] Preferably, when the nutrient component is yeast powder, the addition ratio is 0.1-0.3 g of yeast powder per liter of water.

[0016] Preferably, when the nutrient is milk, the addition ratio is 0.05-0.2 mL of milk per liter of water.

[0017] Preferably, when the nutrient component is milk, the addition ratio is 0.05-0.15 g of bacterial agent per liter of water.

[0018] Preferably, the pH is adjusted by shell powder.

[0019] Preferably, the concentration of the shell powder is 10-20 g / L.

[0020] Preferably, in S2, the screening conditions include: filtering out the cultured algae-eating insects with a filter screen of 80-100 mesh.

[0021] Preferably, in S2, the domestication comprises the following steps: 1) Transfer the selected algae-eating insects to the culture water body containing natural eutrophic water body for cultivation, and regularly monitor the water quality parameters of the culture water body and the growth status of the algae-eating insects; 2) Increase the concentration of natural eutrophic water in the cultivation water and continue the cultivation; 3) Repeat steps 1) and 2) 2~3 times and filter.

[0022] Preferably, in step 1), the weight ratio of the natural eutrophic water in the cultivation water is 10-20wt%.

[0023] Preferably, the cultivation conditions include: a temperature of 20-25° C., a light intensity of 2000-3000 lux, a lighting time of 10-12 h / day, and a time of 5-7 days.

[0024] More preferably, the water quality parameters include ammonia nitrogen, total phosphorus and dissolved oxygen.

[0025] Further preferably, the ammonia nitrogen concentration is 1.5-2.5 mg / L, the total phosphorus concentration is 0.8-1.2 mg / L, and the dissolved oxygen concentration is 5-8 mg / L.

[0026] Furthermore, in step 2), the conditions for continued cultivation include: the concentration of natural eutrophic water in the cultivation water increases to 10-20wt%, the temperature is 20-25°C, the light intensity is 2000-3000 lux, the lighting time is 10-12 h / day, and the time is 5-7 days.

[0027] Preferably, the water body to be treated does not contain high-level predators, and has an ammonia nitrogen concentration of 1.5-2.5 mg / L, a total phosphorus concentration of 0.8-1.2 mg / L, and a dissolved oxygen concentration of 5-8 mg / L.

[0028] Through the above technical scheme, the present invention samples naturally grown algae-eating insects in different water types (ponds, rivers, reservoirs, etc.), combines laboratory screening technology, selects algae-eating insect varieties with high feeding efficiency and strong adaptability to blue-green algae, and initially cultivates the selected excellent varieties by adjusting and optimizing the nutrient composition, dissolved oxygen content, pH and light conditions; in the initial cultivation stage, as the population density and individual development of the algae-eating insects tend to be stable, the algae-eating insects are graded and screened using a precision filter of 80-100 mesh, and the larger algae-eating insects are transferred to water bodies naturally rich in blue-green algae for domestication, so as to improve their ability to adapt to the natural environment; finally, the domesticated and intensively cultivated algae-eating insects are released into the water body that needs to be treated, and the water body should avoid containing high-level predators to ensure that its population can survive effectively and play a role in continuous algae control.

[0029] When the nitrogen and phosphorus concentrations in the water are low, algae-eating worms feed on microalgae, bacteria and organic debris, significantly reducing the nutrient load in the water, while gradually improving the transparency of the water, and eventually achieving a transformation from green turbidity to clear and transparent. This process can not only effectively control the problem of blue-green algae, but also improve the water ecosystem, promote the restoration of natural ecological balance, and provide scientific and effective technical support for the long-term management of water bodies.

[0030] At the same time, the method of the present invention has the advantages of simple operation, eco-friendliness, high efficiency and stability, etc. It provides a scientific and effective technical solution for the treatment of water eutrophication and is expected to produce good economic benefits and social value.

[0031] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0032] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0033] The present invention provides a method for treating water pollution by using algae-eating insects, the method comprising the following steps: S1: Obtaining algae-eating insect seed sources: Collect algae-eating insects from natural water bodies, place them in a static state for cultivation, and filter out the algae-eating insect seed sources; S2: Cultivate and domesticate algae-eating insects: Cultivate, screen and domesticate the filtered algae-eating insect seed sources; S3: Release algae-eating insects: Release the domesticated algae-eating insects into the water body that needs to be treated.

[0034] The method of using algae-eating insects to treat water pollution is to effectively reduce the concentration of algae in the water, improve the transparency of the water, and reduce the accumulation of nutrients such as nitrogen and phosphorus, thereby restoring the ecological environment of the water body. By optimizing the cultivation and release strategy of algae-eating insects and combining the regulation mechanism of the water environment, an eco-friendly treatment plan is proposed.

[0035] In a preferred embodiment of the present invention, in S1, the natural water body includes rivers, lakes, reservoirs and ponds.

[0036] In a preferred embodiment of the present invention, in order to obtain algae-eating insect varieties that are efficient in filtering blue-green algae and have strong adaptability, in S1, the conditions for static cultivation include: the cultivation water is natural water, the temperature is 20~25°C, the light intensity is 2000~3000 lux, the lighting time is 10~12 h / day, and the time is 5~7 days.

[0037] In a preferred embodiment of the present invention, in order to promote the growth and reproduction of algae-eating worms, in S2, the conditions for the expansion culture include: introducing the filtered algae-eating worm seed sources into the cultivation water body, the temperature is 20~25°C, the light intensity is 2000~3000lux, the lighting time is 10~12 h / day, and the cultivation time is 5~7 days.

[0038] In a preferred embodiment of the present invention, in order to promote the growth and reproduction of algae-eating insects, the culture water contains nutrients and has a pH of 7.0-8.5.

[0039] In a preferred embodiment of the present invention, in order to promote the growth and reproduction of algae-eating insects, the nutrient components are selected from one or two or more of yeast powder, milk and bacterial agent.

[0040] In a preferred embodiment of the present invention, in order to promote the growth and reproduction of algae-eating insects, the bacterial agent contains one or two or more of Bacillus licheniformis, Bacillus subtilis and Bacillus cereus.

[0041] In a preferred embodiment of the present invention, in order to promote the growth and reproduction of algae-eating insects, when the nutrient component is yeast powder, the addition ratio is 0.1-0.3 g of yeast powder per liter of water.

[0042] In a preferred embodiment of the present invention, in order to promote the growth and reproduction of algae-eating worms, when the nutrient component is milk, the addition ratio is 0.05-0.2 mL of milk per liter of water.

[0043] In a preferred embodiment of the present invention, in order to promote the growth and reproduction of algae-eating worms, when the nutrient component is milk, the addition ratio is 0.05-0.15 g of the bacterial agent per liter of water.

[0044] In a preferred embodiment of the present invention, in order to control the pH and hardness of the water during cultivation, the pH is adjusted by shell powder.

[0045] In a preferred embodiment of the present invention, the concentration of the shell powder is 10-20 g / L. The shell powder can not only adjust the pH value, but also provide calcium to promote the growth and reproduction of algae-eating insects.

[0046] In a preferred embodiment of the present invention, in order to obtain algae eaters that are larger and reproduce rapidly, in S2, the screening conditions include: filtering out the cultured algae eaters with a filter screen of 80-100 mesh.

[0047] In a preferred embodiment of the present invention, in order to ensure that algae-eating insect individuals with strong adaptability and rapid growth are obtained as the seed source for subsequent application, in S2, the domestication includes the following steps: 1) Transfer the selected algae-eating insects to the culture water body containing natural eutrophic water body for cultivation, and regularly monitor the water quality parameters of the culture water body and the growth status of the algae-eating insects; 2) Increase the concentration of natural eutrophic water in the cultivation water and continue the cultivation; 3) Repeat steps 1) and 2) 2~3 times and filter.

[0048] In a preferred embodiment of the present invention, in order to stimulate the feeding ability and reproduction efficiency of algae-eating insects, in step 1), the weight ratio of the natural eutrophic water in the culture water is 10-20wt%.

[0049] In a preferred embodiment of the present invention, in order to promote the growth and reproduction of algae-eating worms, the cultivation conditions include: temperature of 20-25°C, light intensity of 2000-3000 lux, lighting time of 10-12 h / day, and time of 5-7 days.

[0050] In a preferred embodiment of the present invention, in order to ensure the adaptability and stability of the algae-eating worms, it is necessary to regularly detect the water quality parameters of the culture water body and the growth status of the algae-eating worms, wherein the water quality parameters include ammonia nitrogen, total phosphorus and dissolved oxygen.

[0051] In a preferred embodiment of the present invention, in order to ensure the adaptability and stability of the algae-eating insects, the ammonia nitrogen concentration is 1.5-2.5 mg / L, the total phosphorus concentration is 0.8-1.2 mg / L, and the dissolved oxygen concentration is 5-8 mg / L.

[0052] In a preferred embodiment of the present invention, in order to promote the growth and reproduction of algae-eating worms, in step 2), the conditions for continued cultivation include: increasing the concentration of natural eutrophic water in the cultivation water to 10-20wt%, the temperature is 20-25°C, the light intensity is 2000-3000 lux, the lighting time is 10-12 h / day, and the time is 5-7 days.

[0053] In a preferred embodiment of the present invention, the naturally eutrophic water body is usually selected from river water or pond water rich in nutrients such as nitrogen and phosphorus.

[0054] In a preferred embodiment of the present invention, the ammonia nitrogen concentration and the total phosphorus concentration are adjusted by diluting the natural eutrophic water body to improve the feeding efficiency of algae-eating insects. The ammonia nitrogen concentration is 1.5-2.5 mg / L, the total phosphorus concentration is 0.8-1.2 mg / L, and the dissolved oxygen concentration is 5-8 mg / L.

[0055] In a preferred embodiment of the present invention, in order to better promote the restoration of the ecological environment of the water body and ensure the stable survival of the algae-eating insect population and continue to play a role in controlling algae, the water body to be treated does not contain high-level predators, and the ammonia nitrogen concentration is 1.5-2.5 mg / L, the total phosphorus concentration is 0.8-1.2 mg / L, and the dissolved oxygen concentration is 5-8 mg / L.

[0056] The present invention will be described in detail below by way of examples. In the following examples, all drugs not specifically specified are conventional commercial products. Example 1

[0057] (1) First, water from the river was collected as the cultivation water. The water naturally contained algae-eating worms. The water was cultured for 5 days at a temperature of 22°C, a light intensity of 2500 lux, and 10 hours of light per day. A large number of plankton appeared in the water, and the transparency was significantly improved. After testing, it was confirmed that these plankton were algae-eating worms. A 90-mesh filter was used to catch larger algae-eating worms, thus obtaining algae-eating worms with high efficiency in filtering blue-green algae and strong adaptability. (2) The algae-eating worms were placed in a 300-liter water tank and cultured by feeding them yeast powder. The cultivation water in the water tank was tap water that had been aerated for 3 days. The cultivation temperature was 22°C, the light intensity was 2500 lux, the lighting time was 10 h per day, 0.2 g of yeast powder and 12 g of shell powder were added per liter of water, the pH of the cultivation water was 7.6, and the cultivation lasted for 5 days. (3) Use a 90-mesh filter to scoop out 10 g (wet weight) of the larger algae-eating worms cultivated in step (2), transfer them to cultivation water containing 10 wt% of natural eutrophic water (natural eutrophic water comes from light green water in a natural environment), and cultivate them for 5 days at a cultivation temperature of 22°C, a light intensity of 2500 lux, and a lighting time of 10 h per day. Adjust the weight ratio of natural eutrophic water in the cultivation water to 15 wt% and 20 wt%, respectively. Continue to cultivate the algae-eating worms twice under the above cultivation conditions, and filter out the domesticated algae-eating worms with a 90-mesh filter, which is recorded as B1. Example 2

[0058] The method of Example 1 was followed, except that in step (2), "the algae-eating worms were expanded by feeding yeast powder" was replaced by "the algae-eating worms were expanded by feeding milk", and "0.2 g of yeast powder was added per liter of water" was replaced by "0.1 mL of milk was added per liter of water", and the other steps remained unchanged, to obtain domesticated algae-eating worms, which were recorded as B2. Example 3

[0059] The method of Example 1 was followed, except that in step (2), "expanding the algae-eating worms by feeding them yeast powder" was replaced by "expanding the algae-eating worms by feeding them bacterial agent", and "adding 0.2 g of yeast powder per liter of water" was replaced by "adding 0.1 g of bacterial agent per liter of water", and the other steps remained unchanged, to obtain domesticated algae-eating worms, which were recorded as B3.

[0060] Comparative Example 1 The method of Example 1 is followed, except that shell powder is not added in step (2). The other steps remain unchanged to obtain domesticated algae-eating insects, which are recorded as D1.

[0061] Application Example 1 The algae-eating insects domesticated in Examples 1-3 were placed in three transparent fish tanks (0.06 m 3 ) in an environment without subsequent predators, feed for 3 days and observe and record the water conditions.

[0062] The results showed that after three days of feeding and utilization by the algae-eating worms domesticated in Examples 1-3, the eutrophic water in the three fish tanks changed from light green to clear, indicating that the algae-eating worms obtained by the method of the present invention have high filtering efficiency and can well feed and utilize microalgae and organic debris in the eutrophic water, thereby efficiently promoting the restoration of the water ecological environment.

[0063] Application Example 2 The algae-eating insects domesticated in Example 1 were respectively put into three test groups in which the nitrogen and phosphorus concentrations of the water bodies were adjusted by diluting the naturally eutrophic water bodies, and they were fed for 5 days, and the water state was observed and recorded.

[0064] Among them, the ammonia nitrogen concentration and total phosphorus concentration of the three test groups are shown in Table 1: Table 1 Group Ammonia nitrogen concentration (mg / L) Total phosphorus concentration (mg / L) 1 1.68 0.85 2 2.64 1.12 3 3.87 1.56 The results showed that after 5 days of feeding by the algae-eating insects domesticated in Example 1, the water in the three test groups 1 and 2 gradually changed from light green to clear, while the water color of the test group 3 did not change significantly, indicating that the algae-eating insects screened, cultivated and domesticated by the method of the present invention can treat water bodies with different nitrogen and phosphorus concentrations and are suitable for various types of eutrophic water bodies.

[0065] Application Example 3 The algae-eating insects domesticated in Example 1 and the algae-eating insects domesticated in Comparative Example 1 were respectively placed in two transparent fish tanks (0.06 m 3 ) in an environment without subsequent predators, feed for 3 days and observe and record the water conditions.

[0066] The experimental results show that the transparency of the water body after the algae-eating insects domesticated in Example 1 with the addition of shell powder for 3 days is relatively higher than that of the algae-eating insects domesticated in Comparative Example 1 without the addition of shell powder, because the algae-eating insects domesticated in Example 1 with the addition of shell powder have higher activity and show stronger growth and reproduction ability, so that the water body can be purified faster and the water environment can be repaired. In addition, during the expansion process, since the decomposed products in the water body can be effectively adsorbed on the shell powder at the bottom of the water, the frequency of water replacement is reduced, and the activity of the algae-eating insects is improved.

[0067] In summary, the present invention has significant advantages in the following aspects: (1) High efficiency: By optimizing the algae-eating insect population and the release pattern, blue-green algae in the water can be quickly removed, significantly improving the water transparency; (2) Adaptability: The control effect of algae-eating insects under different nitrogen and phosphorus concentration conditions was verified, and it is applicable to various types of eutrophic water bodies; (3) Eco-friendly: Compared with traditional chemical treatment methods, this method does not introduce secondary pollution and has less impact on other aquatic organisms; (4) Practical feasibility: Based on experiments, it provides reliable parameters and data support, and provides a scientific basis for actual water management.

[0068] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0069] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0070] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for treating water pollution using algae-eating insects, characterized in that: The method comprises the following steps: S1: Obtaining algae-eating insect seed sources: Collect algae-eating insects from natural water bodies, place them in a static state for cultivation, and filter out the algae-eating insect seed sources; S2: Cultivate and domesticate algae-eating insects: Cultivate, screen and domesticate the filtered algae-eating insect seed sources; S3: Release algae-eating insects: Release the domesticated algae-eating insects into the water body that needs to be treated.

2. The method according to claim 1, characterized in that In S1, the natural water bodies include rivers, lakes, reservoirs and ponds; Preferably, in S1, the conditions for static cultivation include: the cultivation water is natural water, the temperature is 20-25°C, the light intensity is 2000-3000 lux, the lighting time is 10-12 h / day, and the time is 5-7 days.

3. The method according to claim 1 or 2, characterized in that: In S2, the conditions for the expansion culture include: introducing the filtered algae-eating worm seed source into the culture water body, the temperature is 20-25°C, the light intensity is 2000-3000 lux, the light time is 10-12 h / day, and the culture time is 5-7 days.

4. The method according to claim 3, wherein the culture water contains nutrients and has a pH of 7.0 to 8.5; Preferably, the nutrient components are selected from one or two or more of yeast powder, milk and bacterial agent; More preferably, the bacterial agent contains one or two or more of Bacillus licheniformis, Bacillus subtilis and Bacillus cereus.

5. The method according to claim 4, wherein when the nutrient is yeast powder, the proportion of yeast powder added is 0.1-0.3 g per liter of water; and / or, When the nutrient is milk, the proportion of milk added is 0.05-0.2 mL per liter of water; and / or, When the nutrient component is milk, the addition ratio is 0.05-0.15 g of the bacterial agent per liter of water.

6. The method according to claim 4, characterized in that The pH is adjusted by shell powder; Preferably, the concentration of the shell powder is 10-20 g / L.

7. The method according to any one of claims 1 to 6, characterized in that: In S2, the screening conditions include: filtering out the cultured algae-eating insects with a filter screen of 80-100 mesh.

8. The method according to any one of claims 1 to 7, characterized in that: In S2, the domestication comprises the following steps: 1) Transfer the selected algae-eating insects to the culture water body containing natural eutrophic water body for cultivation, and regularly monitor the water quality parameters of the culture water body and the growth status of the algae-eating insects; 2) Increase the concentration of natural eutrophic water in the cultivation water and continue the cultivation; 3) Repeat steps 1) and 2) 2~3 times and filter.

9. The method according to claim 8, characterized in that In step 1), the weight ratio of the natural eutrophic water in the cultivation water is 10-20wt%; Preferably, the cultivation conditions include: a temperature of 20-25°C, a light intensity of 2000-3000 lux, a light duration of 10-12 h / day, and a duration of 5-7 days; More preferably, the water quality parameters include ammonia nitrogen, total phosphorus and dissolved oxygen; Further preferably, the ammonia nitrogen concentration is 1.5-2.5 mg / L, the total phosphorus concentration is 0.8-1.2 mg / L, and the dissolved oxygen concentration is 5-8 mg / L; Furthermore, in step 2), the conditions for continued cultivation include: increasing the concentration of natural eutrophic water in the cultivation water to 10-20wt%, the temperature is 20-25°C, the light intensity is 2000-3000 lux, the lighting time is 10-12 h / day, and the time is 5-7 days.

10. The method according to any one of claims 1 to 9, characterized in that: In S3, the water body to be treated does not contain high-level predators, and the ammonia nitrogen concentration is 1.5-2.5 mg / L, the total phosphorus concentration is 0.8-1.2 mg / L, and the dissolved oxygen concentration is 5-8 mg / L.