Method for preventing and treating floating sludge in shallow landscape water body

Abstract

This invention discloses a method for preventing the floating of mud skin in shallow landscape water bodies. Under different conditions, physical methods and combinations of physical and chemical methods are used to prevent mud skin from rising. Physical methods include water level control or agitation and aeration, which involves raising the water level to a certain height before algae removal, maintaining a low transparency to prevent direct sunlight from reaching the bottom, or periodically agitating the bottom of the water through sediment aeration to increase dissolved oxygen content, allowing algae settled at the bottom to be rapidly degraded by microorganisms while maintaining a high turbidity. Chemical methods include coagulation and sedimentation or algaecide methods. These involve preparing a cationic PAM solution and a kaolin solution of a certain concentration, spraying them on the area of ​​algae bloom, and continuously agitating the water to ensure thorough mixing, thus rapidly removing algae through coagulation and sedimentation, or using algaecides to remove algae, preventing mud skin blooms and optimizing the landscape water environment.

Description

Technical Field

[0001] This invention belongs to the field of micro-polluted landscape water treatment technology, specifically relating to a method for preventing mud from floating in shallow landscape water bodies. Background Technology

[0002] Landscape water bodies are an important component of the urban environment. With urban development, various landscape water bodies have been constructed to meet the demand for aesthetically pleasing environments. However, due to the significant impact of human activities, these water bodies are prone to deterioration and algal blooms. The mud crust in the bottom sediment of landscape water bodies is formed by the deposition of sediment particles, plankton, and microbial metabolic waste at the bottom of the pond, combined with algae, zooplankton, and bacteria. Generally, mud crust is found in ponds and aquaculture water bodies. The formation of mud crust requires three conditions: first, abundant organic matter or a large amount of algae at the bottom; second, sufficient sunlight directly reaching the bottom; and third, a suitable temperature.

[0003] Because landscape water bodies are slightly polluted, conventional wastewater treatment methods are unsuitable. When algae blooms, the use of large amounts of algaecides to quickly remove them becomes a common practice. However, this method can lead to a "collapse" phenomenon, where a large number of algae suddenly die, causing a decrease in water transparency and a sudden change in water color. After a collapse, a large amount of sediment often rises to the surface. For example, during summer algae blooms, chemical algae removal causes a large number of algae to die and quickly settle at the bottom of the water, combining with plankton and microbial debris in the sediment to form a high concentration of organic matter. Since algae decomposition consumes oxygen and produces carbon dioxide, the oxygen content in the water drops rapidly, and the pH of the solution decreases. Simultaneously, the levels of ammonia nitrogen, nitrite, and total nitrogen also rise sharply. The collapse makes the water clearer. Under conditions of ample sunlight, direct sunlight reaching the bottom of the water, high water temperature, abundant nutrients, and low pH, benthic algae begin to proliferate, gradually forming a layer of sediment on the surface. Meanwhile, the anaerobic environment caused by the decrease in dissolved oxygen allows anaerobic bacteria to grow rapidly. The large amount of microbubbles such as methane, methanethiol and carbon dioxide produced by their respiration will "crack" the mud skin. At the same time, a large number of microbubbles are attached to the detached mud skin. Under the action of air flotation, they slowly rise to the water surface and form stable mud skin scum. It flows with the waves and accumulates in large quantities on the shore or in the harbor, which seriously affects the water landscape effect.

[0004] This phenomenon of mud sludge typically occurs in ponds and aquaculture waters, but in recent years it has been increasingly observed in shallow landscape water bodies, with mud sludge frequently floating on the surface. Based on appearance, mud sludge can be categorized into three types: dark green, black or dark brown, and yellow. The mud sludge in landscape water bodies is dark green. This type of mud sludge has a slippery feel, is difficult to disperse, and can sometimes be grasped in large handfuls. When rubbed between the fingers, it leaves an oily residue. Testing has revealed that it is primarily composed of organic matter, algae (with Oscillatoria comprising 70% of cyanobacteria and diatoms or green algae accounting for 30%), protozoa, and worms. It emits a fishy odor and significantly impacts the aesthetic appeal of the landscape water body and the surrounding air.

[0005] Currently, there is no effective solution for mud skin blooms in landscape water bodies. The usual approach is repeated dredging, which is relatively easy for small bodies of water. However, for large bodies of water, the mud skin blooms often occur alongside algae blooms caused by algaecides, resulting in highly dispersed and easily broken mud, making dredging extremely difficult. Therefore, there is an urgent need for a method to prevent mud skin from rising in shallow landscape water bodies during algae removal processes, optimize the landscape water environment, and provide effective wastewater treatment measures. Summary of the Invention

[0006] To address the aforementioned deficiencies in existing technologies, the present invention aims to provide a method for preventing mud from rising in shallow landscape water bodies. This method employs different physical methods or a combination of physical and chemical methods to treat algae based on varying light intensities, temperatures, cyanobacterial content, and organic indices of the landscape water body, thereby preventing mud blooms and optimizing the landscape water environment.

[0007] The present invention is achieved through the following technical solution.

[0008] This invention provides a method for preventing mud from floating in shallow landscape water bodies, including physical methods or a combination of physical and chemical methods:

[0009] The physical methods include water level control or agitation and aeration; the chemical methods include coagulation and sedimentation or algaecide methods.

[0010] When the light intensity at the bottom of the landscape water body is >20 μmol / m 2 / s, T<20℃, cyanobacteria account for less than 70% of the total algae content, organic index <0.5, water level control method is adopted;

[0011] When the light intensity at the bottom of the landscape water body is >20 μmol / m 2 / s, T>20℃, cyanobacteria account for less than 70% of the total algae content, organic index <0.5, water level control method + stirring aeration method is adopted;

[0012] When the light intensity at the bottom of the landscape water body is >20 μmol / m 2 / s, T>20℃, cyanobacteria account for more than 70% of the total algae content, organic index<0.5, water level control method + stirring aeration method + coagulation sedimentation method are adopted;

[0013] When the light intensity at the bottom of the landscape water body is >20 μmol / m 2 / s, T>20℃, cyanobacteria account for >70% of the total algae content, organic index>0.5, water level control method + stirring aeration method + algaecide method are adopted.

[0014] Preferably, the water level control method involves adjusting the water level to above 1.5m when the water transparency is 30-40cm, and adjusting the water level to above 2.0m when the water transparency is above 50cm, maintaining the water transparency at 10-20cm.

[0015] Preferably, the stirring aeration method involves periodically aerating the bottom of the water body with a volume greater than 3 mg / L by aerating the bottom sediment, thereby maintaining the turbidity of the water body above 30 NTU.

[0016] Preferably, the coagulation and sedimentation method involves spraying a mixture of cationic polyacrylamide (PAM) solution and kaolin solution onto the surface of the landscape water body where algae have erupted using a high-pressure spray gun, while continuously agitating the water surface at the spraying point to ensure that the solution and algae are fully coagulated and precipitated.

[0017] Preferably, the cationic polyacrylamide (PAM) solution has a solid-liquid ratio of PAM to water of 1:1000-1:2000, and the kaolin solution has a solid-liquid ratio of kaolin to water of 1:2000-1:5000.

[0018] Preferably, the high-pressure spray gun is used to spray the surface of the landscape water body where algae have bloomed by binding two high-pressure spray guns together and spraying the area where algae have gathered in the landscape water body at a rate of 1-2L per square meter of water surface for each type of solution.

[0019] Preferably, the continuous stirring of the water surface at the spraying point refers to stirring the water within a range of 10-20cm below the water surface at a rotation speed of 80-120r / min by manual or mechanical means.

[0020] Preferably, the algaecide method involves applying the algaecide to the surface of the landscape water body where algae blooms; commonly used algaecides include copper sulfate, hydrogen peroxide, potassium permanganate, chlorine preparations, etc.

[0021] Preferably, the chlorine preparation includes sodium hypochlorite and chlorine dioxide.

[0022] The present invention, by adopting the above technical solution, has the following beneficial effects:

[0023] 1. This invention is designed for shallow landscape water bodies with a depth of less than 1.2m. It employs different physical methods or a combination of physical and chemical methods to treat algae based on different light intensities, temperatures, cyanobacterial content, and organic indices of the landscape water body. It can prevent mud skin outbreaks and is applicable to various water quality conditions of landscape water bodies.

[0024] 2. By employing water level control, the light intensity at the bottom of the landscape water body can be effectively reduced to 20 μmol / m². 2 It maintains water transparency at speeds below a certain threshold and is simple and easy to operate.

[0025] 3. The method of water level control combined with stirring and aeration is adopted. By raising the water level and stirring and aerating at the bottom, the light intensity at the bottom of the water body is reduced, and the temperature at the bottom of the water body is effectively reduced to below 20℃, making the water turbid and reducing the light conditions. The project is small in scale and has a short operation cycle.

[0026] 4. By using a combination of water level control, agitation and aeration, and coagulation and sedimentation, and under controlled light intensity and temperature conditions, a mixed solution is sprayed onto the algae accumulation area of ​​the water body to effectively and rapidly reduce the content of cyanobacteria in the water body, so that cyanobacteria account for less than 70% of the total algae content, and there are no significant adverse effects on aquatic organisms and plants during the implementation of the project.

[0027] 5. The method combines water level control, agitation and aeration, and algaecide application. Adding algaecide can directly and quickly reduce the content of blue-green algae, lowering the organic pollution index to below 0.5. Furthermore, the chemicals used are all conventional agents in the water treatment industry, resulting in low cost and no pollution. Attached Figure Description

[0028] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1 The algae removal effect of PAM+kaolin coagulation sedimentation method;

[0030] Figure 2 The variation in water temperature of the landscape water bodies from January to December;

[0031] Figure 3 The relationship between water depth and bottom light intensity in water bodies with different transparency levels;

[0032] Figure 4 The effects of different aeration methods on algae in landscape water bodies. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0034] This invention provides a method for preventing mud from floating in shallow landscape water bodies. The method involves physical methods or a combination of physical and chemical methods. The physical method is used as a supporting measure for emergency treatment of algae outbreaks with algaecides to prevent mud from floating during the algae removal process in shallow landscape water bodies. The chemical method is used as an alternative to conventional algaecides to prevent algae outbreaks and mud from floating in shallow landscape water bodies.

[0035] Physical methods include water level control or aeration; chemical methods include coagulation and sedimentation or algaecides. Different control methods are employed for the following four different situations.

[0036] 1) When the light intensity at the bottom of the landscape water body is >20 μmol / m 2 / s, temperature T<20℃, cyanobacteria account for less than 70% of total algae content, organic index <0.5, water level control method is adopted;

[0037] 2) When the light intensity at the bottom of the landscape water body is >20 μmol / m 2 / s, temperature T>20℃, cyanobacteria account for less than 70% of the total algae content, organic index <0.5, water level control method + stirring aeration method is adopted;

[0038] 3) When the light intensity at the bottom of the landscape water body is >20 μmol / m 2 / s, temperature T>20℃, cyanobacteria account for more than 70% of the total algae content, organic index <0.5, water level control method + stirring aeration method + coagulation sedimentation method are adopted;

[0039] 4) When the light intensity at the bottom of the landscape water body is >20 μmol / m 2 / s, temperature T>20℃, cyanobacteria account for >70% of the total algae content, organic index>0.5, water level control method + stirring aeration method + algaecide method are adopted.

[0040] Among them, the water level control method is to adjust the water level to above 1.5m when the water transparency is 30-40cm; and to adjust the water level to above 2.0m when the water transparency is above 50cm, so as to maintain the water transparency at 10-20cm.

[0041] The stirring aeration method involves periodically aerating the bottom of the water body with a volume greater than 3 mg / L by aerating the bottom sediment, thereby maintaining the turbidity of the water body above 30 NTU.

[0042] The coagulation and sedimentation method involves mixing a cationic polyacrylamide (PAM) solution and a kaolin solution. The cationic PAM solution has a solid-liquid ratio of PAM to water of 1:1000-1:2000, and the kaolin solution has a solid-liquid ratio of kaolin to water of 1:2000-1:5000. The mixture is sprayed onto the surface of the water feature where algae have formed using a high-pressure spray gun. Two high-pressure spray guns are bundled together, and 1-2 liters of each solution are applied per square meter of water surface. The sprayed solution is applied to the area where algae have accumulated. The water surface within 10-20 cm below the sprayed area is continuously agitated manually or mechanically to ensure thorough coagulation and sedimentation of the solution and algae.

[0043] The algaecide method involves applying algaecides to the surface of landscape water bodies where algae blooms occur. Algaecides can be copper sulfate, hydrogen peroxide, potassium permanganate, or chlorine-based agents, with chlorine-based agents being sodium hypochlorite or chlorine dioxide.

[0044] The principles involved in the method of the present invention will be further described in detail below through examples.

[0045] This invention uses the organic pollution index (OI) method to analyze the degree of organic matter pollution in sediments, providing a further evaluation of the current state of sediment pollution. The calculation method for the organic pollution index (OI) is as follows:

[0046] OI = OC × ON

[0047] OC = OM / 1.724

[0048] ON = TN × 0.95

[0049] In the formula, OI is the organic index, %; OC is organic carbon, %; and ON is organic nitrogen, % (where total nitrogen needs to be converted to a percentage unit, i.e., 1000 mg·kg). -1 =0.1%, OM is organic matter, %. The evaluation criteria for pollution level based on the organic pollution index are shown in Table 1.

[0050] Table 1 Evaluation Criteria for Organic Index of Sediment

[0051]

[0052] There are two important aspects to prevent the formation of mud skin in landscape water bodies: one is to disrupt the conditions for mud skin formation, which is the physical method adopted in this invention; the other is to replace chemical algaecides with coagulation and sedimentation methods, i.e., chemical methods.

[0053] There are many ways to disrupt the conditions for mud skin formation, but the most convenient method is to avoid direct sunlight on the bottom mud of the water body after "algae fall". There are two methods: one is to raise the water level of the landscape water body to a suitable height before "algae fall" to increase the turbidity of the water body and reduce the light conditions.

[0054] In the first scenario, when the light intensity at the bottom of the water feature is >20 μmol / m² 2 / s, temperature T<20℃, cyanobacteria account for <70% of total algae content, organic index <0.5.

[0055] In one embodiment, two landscape water bodies with different transparency levels (30-40cm and 50-60cm respectively) in Xi'an City were selected. The relationship between water depth and light intensity is as follows: Figure 1 As shown, by Figure 1 It is known that the light intensity at the bottom of a water body decreases rapidly with increasing water depth. When the transparency of a landscape water body is 30-40cm, a very low light intensity of approximately 20umol / m² can be maintained when the water level reaches above 1.5m. 2 / s. For water bodies with a transparency of 50-60cm, the water level must reach at least 2.0m. That is, when the water transparency is 30-40cm, adjust the water level to at least 1.5m; when the water transparency is above 50cm, adjust the water level to at least 2.0m, maintaining the water transparency between 10-20cm.

[0056] In the second scenario, when the light intensity at the bottom of the landscape water body is >20 μmol / m 2 / s, temperature T>20℃, cyanobacteria accounting for <70% of total algae content, organic index <0.5, water level control method + stirring aeration method is adopted. Through mechanical stirring and bottom aeration, the water body is made turbid, reducing light conditions.

[0057] In one embodiment, a landscape water body in Xi'an was selected, and the water temperature of the water body was measured from January to December. Algal blooms mainly occur from April to September each year. Figure 2 It is known that the water temperature is above 20℃ from April to September. The water temperature can be lowered by reducing light conditions through agitation and aeration. In terms of ease of implementation, aeration is easier to achieve. In recent years, surface aerators have been widely used in urban landscape water bodies to alleviate eutrophication.

[0058] In one embodiment, a microcosmic water feature was constructed in the laboratory. The bottom of the feature was uniformly covered with river mud and equipped with microporous aeration heads. The effects of mud aeration (i.e., aeration of the bottom mud to create turbidity) and water aeration on algae in the water were simulated and compared. The experiment found that the turbidity of the water under both water and mud aeration initially increased and then decreased. Because mud aeration caused the suspension of bottom mud particles, the turbidity of the water under both aeration and non-aeration conditions was greater throughout the experiment than that under water aeration and non-aeration conditions.

[0059] like Figure 3As shown, mud aeration not only maintains a high water turbidity but also effectively inhibits algae growth. After 49 days, the total number of algal cells in the water was 271.1 and 397.7 times smaller than that of no aeration and water aeration, respectively. Therefore, this invention proposes using a negative pressure self-priming jet aerator or a submersible blower aerator to aerate the bottom mud of the water body, with an aeration rate greater than 3 mg / L.

[0060] The third scenario is when the light intensity at the bottom of the landscape water body is >20 μmol / m². 2 For landscape water bodies with a cyanobacteria content >70% and an organic index <0.5, the following methods are employed: water level control, agitation and aeration, and coagulation and sedimentation. For landscape water bodies where cyanobacteria account for >70% of the total algae content, further coagulation and sedimentation are required.

[0061] The use of coagulation and sedimentation methods involves the selection of coagulants. In one embodiment, such as... Figure 4 As shown, a water sample from a landscape water body in Xi'an was placed in a 100mL beaker, and a large number of cyanobacteria and green algae were found suspended in the sample. A PAM solution with a solid-liquid ratio of 1:1000 and a kaolin solution with a solid-liquid ratio of 1:2000 were prepared. When only 1mL of PAM solution was added, the algae could aggregate well, but the aggregates were in a floating state, which was not conducive to collection and disposal. However, when 1mL each of PAM and kaolin solutions were added simultaneously, the water quickly underwent coagulation and sedimentation, and the formation of aggregated flocs was very rapid. These flocs were large, dense, and settled quickly.

[0062] In one embodiment, PAM was prepared into a solution with a solid-liquid ratio of 1:1000, and kaolin was prepared into a solution with a solid-liquid ratio of 1:2000. The two solutions were sprayed simultaneously, and the surface of the water was continuously stirred with a stick. It was found that a large number of flocs were formed in the water and continued to sink. However, because the kaolin solution sank faster, the flocs could not adsorb the kaolin, resulting in some floc fragments floating on the surface of the water.

[0063] To achieve better results, this invention proposes bundling two high-pressure spray guns together to simultaneously spray PAM and kaolin solutions onto areas of algae accumulation in the landscape water. The water within a 10-20cm depth below the surface is then stirred manually or mechanically using a stick, a stirring paddle, or a water gun at a speed of 80-120 rpm. Repeated calculations have shown that appropriately increasing the concentration of the PAM and kaolin solutions yields better results, but it cannot be too high, as this will lead to excessively large flocs that are easily broken up, resulting in more debris. Therefore, a solid-liquid ratio of 1:1000-1:2000 and 1:2000-1:5000 for the PAM and kaolin solutions is more suitable. Simultaneously, calculations indicate that spraying 1-2L per square meter of water surface and stirring to a depth of 10-20cm is appropriate. These ratios can also be adjusted according to the quantity and type of algae in the actual landscape water. After spraying PAM and kaolin solutions simultaneously into the algae bloom area, the surface of the water is stirred. The coagulant adsorbs the algae in the water to form a large number of light green flocs, which continue to sink and the water gradually becomes clear, thereby achieving the purpose of removing algae.

[0064] Experiments showed that cationic polyacrylamide (PAM) solutions with a solid-liquid ratio of PAM to water of 1:1500, 1:1800, and 1:2000, and kaolin solutions with a solid-liquid ratio of kaolin to water of 1:2000, 1:3000, 1:3500, 1:4000, 1:4500, and 1:5000, also exhibited rapid coagulation and sedimentation in water bodies, forming aggregated flocs at a very fast rate, with large floc volumes and high density.

[0065] Furthermore, the experiment revealed that anionic coagulants had no aggregation effect. This is because algae are negatively charged, and the addition of anionic coagulants only increases the dispersion of algae, preventing aggregation. Although aluminum salt coagulants have some effect, they pose a risk of secondary aluminum pollution. In contrast, PAM coagulant is a biodegradable organic compound, and kaolin is a soil mineral that does not cause secondary pollution. Therefore, this invention employs a "PAM + kaolin" method to coagulate and settle algae in landscape water bodies.

[0066] Although the "PAM + kaolin" coagulation and sedimentation method achieved good algae removal results in landscape water bodies in the laboratory, in open water bodies, the large volume of water can quickly dilute the coagulant, so appropriate implementation methods need to be adopted.

[0067] Coagulation and sedimentation can replace conventional algaecides for emergency treatment of algal blooms in shallow landscape water bodies. Moreover, the chemical agents used, such as PAM, are conventional agents in the water treatment industry, which are low in cost and pollution-free. Kaolin is a natural mineral and is pollution-free.

[0068] The fourth scenario is when the light intensity at the bottom of the water feature is >20 μmol / m². 2 / s, temperature T>20℃, cyanobacteria account for >70% of the total algae content, organic index>0.5, water level control method + stirring aeration method + algaecide method are adopted.

[0069] For landscape water bodies with an organic index > 0.5, it is necessary to further adopt algaecide methods to replace coagulation and sedimentation methods.

[0070] Algaecides are applied to the surface of water features experiencing algal blooms. Common algaecides include copper sulfate, hydrogen peroxide, potassium permanganate, and chlorine-based agents. Chlorine-based agents include sodium hypochlorite or chlorine dioxide.

[0071] Different algaecides have different characteristics and application conditions. Copper sulfate has a relatively weak effect on killing bacteria and viruses, but it is highly effective at killing algae. When there are too many plankton, too much fertilizer, or a lot of Noctiluca scintillans, dinoflagellates, and suspended solids in the pond, copper sulfate at a concentration of 0.7 mg / L can be sprayed. Application must be carried out in a sunny weather. The water quality will gradually become clearer and the transparency will reach the ideal value 3-4 hours after application.

[0072] Hydrogen peroxide has oxidizing properties and can damage algae. The higher the concentration, the stronger its bactericidal and algae-removing effects. However, high concentrations can negatively impact fish and other aquatic life. A good algae-removing effect can be achieved by injecting a 2% hydrogen peroxide solution using a syringe and applying it to the algae in spots. The dosage is approximately 10 ml per 100 liters of water. Safety precautions should be taken when using hydrogen peroxide for algae removal; avoid prolonged use and high concentrations.

[0073] Potassium permanganate, as an algaecide, can significantly improve algae removal efficiency and reduce ultraviolet absorption. When the dosage of potassium permanganate is 1-2 mg / L and the contact time is not less than 2 hours, the algae killing rate of potassium permanganate can reach over 90%. However, potassium permanganate combines with water to produce manganese oxide, which is toxic to fish and other aquatic organisms. Therefore, the dosage of potassium permanganate must be carefully controlled to avoid adverse effects on water quality.

[0074] Chlorine-based algaecides can quickly kill algae in water and effectively control algae growth. Compared to other algaecides, chlorine-based algaecides are less expensive and have a relatively lower environmental impact. The dosage of chlorine dioxide as an algaecide is 0.2-0.3 mg / L, and it needs to be fully dissolved before use. The optimal dosage of sodium hypochlorite is 3 mg / L. If the water quality is poor or there is a high algae population, the dosage may need to be increased. Long-term use of sodium hypochlorite can easily lead to resistance in bacteria and algae; therefore, it should be used alternately with other algaecides.

[0075] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.

Claims

1. A method for preventing the floating of mud skin in shallow landscape water bodies, characterized in that, Including physical methods or a combination of physical and chemical methods: The physical methods include water level control or agitation and aeration; the chemical methods include coagulation and sedimentation or algaecide methods. When the light intensity at the bottom of the landscape water body is >20 μmol / (m²) 2 •s), temperature T < 20℃, cyanobacteria account for < 70% of total algae content, organic index < 0.5, water level control method is adopted; When the light intensity at the bottom of the landscape water body is >20 μmol / (m²) 2 •s), temperature T>20℃, cyanobacteria account for less than 70% of the total algae content, organic index <0.5, water level control method + stirring aeration method is adopted; When the light intensity at the bottom of the landscape water body is >20 μmol / (m²) 2 •s), temperature T>20℃, cyanobacteria account for more than 70% of the total algae content, organic index <0.5, water level control method + stirring aeration method + coagulation sedimentation method are adopted; When the light intensity at the bottom of the landscape water body is >20 μmol / (m²) 2 •s), temperature T>20℃, cyanobacteria account for >70% of the total algae content, organic index>0.5, water level control method + stirring aeration method + algaecide method; The water level control method involves adjusting the water level to above 1.5m when the water transparency is between 30-40cm, and adjusting the water level to above 2.0m when the water transparency is above 50cm, maintaining the water transparency at 10-20cm. The stirring aeration method involves periodically aerating the bottom of the water body with a volume greater than 3 mg / L by aerating the bottom sediment, thereby maintaining the turbidity of the water body above 30 NTU. The coagulation and sedimentation method involves spraying a mixture of cationic polyacrylamide (PAM) solution and kaolin solution onto the surface of the landscape water body where algae have bloomed using a high-pressure spray gun, while continuously agitating the water surface at the spraying point to ensure that the solution and algae are fully coagulated and precipitated. The algaecide method involves applying an algaecide to the surface of a landscape water body where algae blooms; the algaecide is copper sulfate, hydrogen peroxide, potassium permanganate, or a chlorine-based agent.

2. The method for preventing mud from floating in shallow landscape water bodies according to claim 1, characterized in that, The cationic polyacrylamide (PAM) solution has a solid-liquid ratio of cationic polyacrylamide (PAM) to water of 1:1000-1:2000, and the kaolin solution has a solid-liquid ratio of kaolin to water of 1:2000-1:5000.

3. The method for preventing mud from floating in shallow landscape water bodies according to claim 1, characterized in that, The high-pressure spray gun is used to spray the surface of the landscape water body where algae have bloomed. Two high-pressure spray guns are tied together and sprayed into the area where algae have gathered, according to the amount of each solution per square meter of water surface.

4. The method for preventing mud from floating in shallow landscape water bodies according to claim 1, characterized in that, The continuous stirring of the water surface at the spraying point refers to stirring the water within a range of 10-20cm below the water surface at a speed of 80-120r / min, either manually or mechanically.

5. The method for preventing mud from floating in shallow landscape water bodies according to claim 1, characterized in that, The chlorine preparation is sodium hypochlorite or chlorine dioxide.

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