Method for controlling dispersive cyanobacterial bloom in local water area of water intake

Abstract

The invention discloses a water intake local water area dispersive cyanobacterial bloom control method, which comprises the following steps: 1, arranging a flow guide enclosure and arranging a gas stripping flow making structure, 2, preparing nano titanium dioxide powder and preparing the nano titanium dioxide powder into spraying slurry, 3, coating a sunshade net with the spraying slurry to prepare a photocatalytic sunshade net, and 4, carrying out water intake local water area dispersive cyanobacterial bloom control on the photocatalytic sunshade net. 4, a photocatalytic sunshade net is arranged, and floating plants are planted; the flow guide enclosure is arranged to be matched with the gas stripping flow making structure, surface water in the control area can be conveyed out of the area through the gas stripping flow making structure while blue-green algae in the upper layer in the external area are prevented from entering, the fluidity of surface water in the area is improved, and therefore formation of blue-green algae bloom is avoided; meanwhile, a sunshade net coated with titanium dioxide is arranged in the region, so that blue-green algae and metabolites thereof are oxidized and decomposed by utilizing photocatalysis while the photosynthesis of the algae is reduced by shading, and the water quality is further purified.

Description

Technical Field

[0001] The invention relates to the technical field of water source management, and in particular to a method for controlling diffuse blue algae blooms in local waters of a water intake. Background Art

[0002] The water quality of the water source directly affects the safety of water supply. When filamentous cyanobacteria such as Pseudo-cylindrical spores, Hypophthalmia lapilli, and Pseudo-anabaena form diffuse algae blooms, they are usually evenly distributed in the middle and upper layers of the water body (generally about 0-6m underwater), unlike Microcystis, which gather on the water surface to form surface algae blooms. Such filamentous cyanobacteria may produce toxins and odorous substances that threaten the safety of water supply and the health of the ecosystem. However, there is currently no effective disposal method for such diffuse algae blooms at home and abroad. Therefore, the present invention proposes a method for controlling diffuse cyanobacterial blooms in local waters of water intakes to solve the problems existing in the prior art. Summary of the invention

[0003] In view of the above problems, the purpose of the present invention is to propose a method for controlling diffuse cyanobacteria blooms in local waters of a water intake. The method for controlling diffuse cyanobacteria blooms in local waters of a water intake can block the entry of upper cyanobacteria in the external area by setting a diversion enclosure and an air lift flow structure. At the same time, the air lift flow structure can be used to transport surface water in the control area to the outside of the area, thereby improving the fluidity of the surface water in the area and avoiding the formation of cyanobacteria blooms. At the same time, a sunshade net coated with titanium dioxide is arranged in the area. While shading to reduce the photosynthesis of algae, photocatalysis is used to oxidize and decompose cyanobacteria and their metabolites, thereby further purifying the water quality.

[0004] To achieve the purpose of the present invention, the present invention is implemented by the following technical scheme: a method for controlling diffuse cyanobacteria bloom in local waters of a water intake, comprising the following steps:

[0005] Step 1: first, set up diversion enclosures at all bays in the local waters of the water intake area, and set up an air lift flow structure in the middle of the diversion enclosure;

[0006] Step 2: firstly prepare nano titanium dioxide powder by sol-gel synthesis method, then mix the nano titanium dioxide powder with resin, dispersant and stabilizer to prepare spray slurry for use;

[0007] Step 3: unfold the sunshade net and lay it flat on the ground, then use a spraying device to evenly spray the spray slurry on the surface of the sunshade net, and then dry it to obtain a photocatalytic sunshade net;

[0008] Step 4: Deploy ecological floating beds in the waters inside the bay mouth close to the opposite bank, arrange photocatalytic sunshade nets at intervals between the ecological floating beds, and then plant floating plants in the ecological floating beds.

[0009] Further improvements are as follows: in step one, the depth of the diversion enclosure is 6-7m, the gas lift flow structure includes a floating body, a fixed box, a diversion port, an air outlet, a telescopic diversion pipe and an air inlet head, a fixed box is fixedly arranged above the floating body, a diversion port is transversely arranged in the fixed box, and multiple groups of diversion ports are symmetrically arranged, an air outlet is arranged on the fixed box, corresponding to the diversion port, a telescopic diversion pipe is arranged below the fixed box, and an air inlet head is arranged upward from the lower end of the telescopic diversion pipe.

[0010] Further improvements are: the upper end of the telescopic guide pipe is connected to the guide port, the lower part of the air outlet is also connected to the guide port, telescopic fixed anchor chains are symmetrically arranged on both sides of the floating body for fixing the floating body to prevent drifting with the water flow, and the lower part of the air inlet head is connected to the external fan room through a connecting air pipe to provide high-pressure air.

[0011] A further improvement is that the nano titanium dioxide powder is prepared by first mixing isopropyl alcohol and tetrabutyl titanate to obtain solution A, then dissolving glacial acetic acid in deionized water and mixing to obtain solution B, then slowly dropping solution B into solution A and rapidly stirring with a magnetic stirrer to form a sol, and finally drying and calcining the sol to obtain the nano titanium dioxide powder.

[0012] The further improvement is that the mass ratio of the isopropanol to tetrabutyl titanate is 2:1, the sol is first naturally air-dried for 30-40 minutes when drying, and then placed in an oven at 105°C for 2-3 hours to obtain a dry gel, and finally the dry gel is nano-grinded to obtain a nano powder, which is placed in a muffle furnace and calcined at 700-900°C for 2-3 hours to obtain a nano titanium dioxide powder.

[0013] A further improvement is that in the step 2, the mixing mass ratio of the nano titanium dioxide powder, the resin, the dispersant and the stabilizer is 20-25:60-70:3-5:5-8, wherein the resin is an organosilicon-modified acrylic resin, the dispersant is one of sodium pyrophosphate, sodium polyacrylate and potassium tripolyphosphate, and the stabilizer is one of reduced graphene oxide powder and mesoporous molecular sieve SBA15.

[0014] Further improvements are: in the step three, the drying condition of the sunshade net after spraying is to stand for 8-12 hours in a dry and ventilated environment; in the step four, when arranging the photocatalytic sunshade net, it is sunk to a depth of 0.8-1.2m below the water surface with the side sprayed with the slurry facing; the floating plant is one of water lily, rain lily and water lily.

[0015] The beneficial effects of the present invention are as follows: by setting a guide enclosure in conjunction with an air lift flow structure, the present invention can block the entry of upper cyanobacteria in the external area while utilizing the air lift flow structure to transport surface water in the control area to the outside of the area, thereby improving the fluidity of the surface water in the area, thereby avoiding the formation of cyanobacterial blooms; at the same time, by arranging a sunshade net coated with titanium dioxide in the area, while shading and reducing the photosynthesis of algae, photocatalysis is utilized to oxidize and decompose cyanobacteria and their metabolites, thereby further purifying the water quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a flow chart of the method of the present invention.

[0017] Figure 2 This is a gas lift flow structure diagram of the present invention.

[0018] Among them: 1. Floating body; 2. Fixed box; 3. Diversion port; 4. Air outlet; 5. Telescopic diversion pipe; 6. Air inlet head; 7. Telescopic fixed anchor chain; 8. Connecting air pipe. DETAILED DESCRIPTION

[0019] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0020] Filamentous cyanobacteria such as Pseudo-cylindrical spores, Hypocrea, and Pseudo-anabaena may produce toxins and odorous substances that threaten water supply safety and ecosystem health; when they form diffuse algal blooms, they are usually evenly distributed in the middle and upper layers of the water body (generally about 0-6m underwater), unlike Microcystis, which gather on the water surface to form surface algal blooms. Currently, there is no effective disposal method for diffuse algal blooms such as filamentous cyanobacteria at home and abroad.

[0021] The four necessary conditions for filamentous cyanobacteria to form algal blooms include: (1) high water temperature, (2) continuous clear weather (strong light), (3) sufficient nitrogen and phosphorus nutrients, and (4) still or low-flowing water. Among them, water temperature is an uncontrollable factor, so it is impossible to control it by controlling water temperature; the focus of nitrogen and phosphorus nutrient reduction is on land, and the process is slow; for large areas of water, it is basically impossible to regulate the fluidity of the water body. In the short term, artificial rainfall can be used to change the weather and break the growth pattern of the continuous proliferation of cyanobacteria, but it cannot meet the long-term control needs.

[0022] Example 1

[0023] according to Figure 1 and Figure 2 As shown, this embodiment provides a method for controlling diffuse cyanobacteria bloom in local waters of a water intake, comprising the following steps:

[0024] Step 1: First, diversion enclosures are set up at all bays in the local waters of the water intake area. The depth of the diversion enclosure is 6m, which can effectively block the upper layer of cyanobacteria from entering the area and avoid the outbreak of cyanobacteria blooms. An air lift flow structure is set up in the middle section of the diversion enclosure;

[0025] The air lift flow structure includes a floating body 1, a fixed box 2, a guide port 3, an air outlet 4, a telescopic guide pipe 5 and an air inlet head 6. A fixed box 2 is fixedly arranged above the floating body 1, a guide port 3 is transversely arranged in the fixed box 2, and multiple groups of guide ports are symmetrically arranged. An air outlet 4 is arranged on the fixed box 2, corresponding to the guide port. A telescopic guide pipe 5 is arranged below the fixed box 2, and an air inlet head 6 is arranged upward at the lower end of the telescopic guide pipe 5;

[0026] The upper end of the telescopic guide pipe 5 is connected to the guide port 3, and the lower end of the air outlet 4 is also connected to the guide port 3. Telescopic fixed anchor chains 7 are symmetrically arranged on both sides of the floating body 1 to fix the floating body and prevent it from drifting with the water flow. The lower part of the air inlet head 6 is connected to the external fan room through the connecting air pipe 8 to provide high-pressure air, and the surface water in the control area is transported to the outside of the area by using the air lift flow control technology, so as to improve the fluidity of the surface water in the area.

[0027] Step 2: firstly prepare nano titanium dioxide powder by sol-gel synthesis method, then mix the nano titanium dioxide powder with organosilicon-modified acrylic resin, sodium polyacrylate and reduced graphene oxide powder to prepare spray slurry for standby use;

[0028] The nano titanium dioxide powder is prepared by first mixing isopropanol and tetrabutyl titanate at a mixing mass ratio of 2:1 to obtain solution A, then dissolving glacial acetic acid in deionized water and mixing to obtain solution B, then slowly dropping solution B into solution A and rapidly stirring with a magnetic stirrer to form a sol, air-drying the sol for 30 minutes, and then placing it in an oven at 105° C. for 3 hours to obtain a dry gel, and finally nano-grinding the dry gel to obtain a nano powder, placing it in a muffle furnace, and calcining it at 800° C. for 3 hours to obtain a nano titanium dioxide powder;

[0029] The mixing mass ratio of nano titanium dioxide powder, silicone-modified acrylic resin, sodium polyacrylate and reduced graphene oxide powder is 20:70:5:5.

[0030] Step 3: unfold the sunshade net and lay it flat on the ground, then use a spraying device to evenly spray the spray slurry on the surface of the sunshade net, and then let it stand in a dry and ventilated environment for 10 hours to dry it to obtain a photocatalytic sunshade net;

[0031] Step 4: Deploy ecological floating beds in the waters near the opposite bank inside the bay, and arrange photocatalytic sunshade nets at intervals between the ecological floating beds, and then plant floating plants such as water lilies in the ecological floating beds. Planting floating plants can reduce the nitrogen, phosphorus and potassium content in the water in the area, reduce the nutrients for the massive reproduction of cyanobacteria to avoid the outbreak of cyanobacterial blooms;

[0032] When arranging the photocatalytic sunshade net, it is sunk to a depth of 1m below the water surface with the side sprayed with slurry facing upwards, so as to reduce the underwater light intensity in the control area, reduce the photosynthesis and biomass of algae, and at the same time, through the action of titanium dioxide photocatalytic materials, strong oxidizing substances such as hydroxyl free radicals are produced under light conditions, which oxidatively decompose cyanobacteria and their metabolites, further purifying the water quality.

[0033] Example 2

[0034] according to Figure 1 and Figure 2 As shown, this embodiment provides a method for controlling diffuse cyanobacteria bloom in local waters of a water intake, comprising the following steps:

[0035] Step 1: First, diversion enclosures are set up at all bays in the local waters of the water intake area. The depth of the diversion enclosure is 6m, which can effectively block the upper layer of cyanobacteria from entering the area and avoid the outbreak of cyanobacteria blooms. An air lift flow structure is set up in the middle section of the diversion enclosure;

[0036] The air lift flow structure includes a floating body 1, a fixed box 2, a guide port 3, an air outlet 4, a telescopic guide pipe 5 and an air inlet head 6. A fixed box 2 is fixedly arranged above the floating body 1, a guide port 3 is transversely arranged in the fixed box 2, and multiple groups of guide ports are symmetrically arranged. An air outlet 4 is arranged on the fixed box 2, corresponding to the guide port. A telescopic guide pipe 5 is arranged below the fixed box 2, and an air inlet head 6 is arranged upward at the lower end of the telescopic guide pipe 5;

[0037] The upper end of the telescopic guide pipe 5 is connected to the guide port 3, and the lower end of the air outlet 4 is also connected to the guide port 3. Telescopic fixed anchor chains 7 are symmetrically arranged on both sides of the floating body 1 to fix the floating body and prevent it from drifting with the water flow. The lower part of the air inlet head 6 is connected to the external fan room through the connecting air pipe 8 to provide high-pressure air, and the surface water in the control area is transported to the outside of the area by using the air lift flow control technology, so as to improve the fluidity of the surface water in the area.

[0038] Step 2: firstly prepare nano titanium dioxide powder by sol-gel synthesis method, then mix the nano titanium dioxide powder with organosilicon-modified acrylic resin, sodium pyrophosphate and mesoporous molecular sieve SBA15 to prepare spray slurry for standby use;

[0039] The nano titanium dioxide powder is prepared by first mixing isopropanol and tetrabutyl titanate at a mixing mass ratio of 2:1 to obtain solution A, then dissolving glacial acetic acid in deionized water and mixing to obtain solution B, then slowly dropping solution B into solution A and rapidly stirring with a magnetic stirrer to form a sol, naturally air-drying the sol for 40 minutes, then placing it in an oven at 105° C. for 2.5 hours to obtain a dry gel, and finally nano-grinding the dry gel to obtain a nano powder, placing it in a muffle furnace, and calcining it at 800° C. for 3 hours to obtain a nano titanium dioxide powder;

[0040] The mixing mass ratio of nano titanium dioxide powder, silicone-modified acrylic resin, sodium pyrophosphate and mesoporous molecular sieve SBA15 is 25:65:4:6.

[0041] Step 3: unfold the sunshade net and lay it flat on the ground, then use a spraying device to evenly spray the spray slurry on the surface of the sunshade net, and then let it stand in a dry and ventilated environment for 12 hours to dry it to obtain a photocatalytic sunshade net;

[0042] Step 4: Ecological floating beds are laid out in the waters near the opposite bank inside the bay, and photocatalytic sunshade nets are arranged at intervals between the ecological floating beds. Then floating plants such as water chestnuts are planted in the ecological floating beds. Planting floating plants can reduce the nitrogen, phosphorus and potassium content in the water in the area, reduce the nutrients for the massive reproduction of cyanobacteria, and avoid the outbreak of cyanobacterial blooms.

[0043] When arranging the photocatalytic sunshade net, it is sunk to a depth of 0.8m below the water surface with the side sprayed with slurry facing upwards, so as to reduce the underwater light intensity in the control area, reduce the photosynthesis and biomass of algae, and at the same time, through the action of titanium dioxide photocatalytic materials, strong oxidizing substances such as hydroxyl free radicals are produced under light conditions, which oxidatively decompose cyanobacteria and their metabolites, further purifying the water quality.

[0044] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for controlling diffuse cyanobacteria blooms in local waters of a water intake, characterized in that: The following steps are involved: Step 1: first, set up diversion enclosures at all bays in the local waters of the water intake area, and set up an air lift flow structure in the middle of the diversion enclosure; Step 2: firstly prepare nano titanium dioxide powder by sol-gel synthesis method, then mix the nano titanium dioxide powder with resin, dispersant and stabilizer to prepare spray slurry for use; Step 3: unfold the sunshade net and lay it flat on the ground, then use a spraying device to evenly spray the spray slurry on the surface of the sunshade net, and then dry it to obtain a photocatalytic sunshade net; Step 4: Deploy ecological floating beds in the waters inside the bay mouth close to the opposite bank, arrange photocatalytic sunshade nets at intervals between the ecological floating beds, and then plant floating plants in the ecological floating beds.

2. The method for controlling diffuse cyanobacteria bloom in local waters of a water intake according to claim 1, characterized in that: The depth of the flow guide enclosure in step 1 is 6-7 m. The air lift flow generation structure comprises a floating body (1), a fixed box (2), a flow guide port (3), an air outlet (4), a telescopic flow guide pipe (5) and an air inlet head (6). A fixed box (2) is provided above the floating body (1), a flow guide port (3) is transversely provided in the fixed box (2), an air outlet (4) is provided on the fixed box (2), a telescopic flow guide pipe (5) is provided below the fixed box (2), and an air inlet head (6) is provided at the lower end of the telescopic flow guide pipe (5) facing upward.

3. The method for controlling diffuse cyanobacteria bloom in local waters of a water intake according to claim 2, characterized in that: The upper end of the telescopic guide pipe (5) is connected to the guide port (3), and the lower end of the air outlet (4) is also connected to the guide port (3). Telescopic fixed anchor chains (7) are symmetrically provided on both sides of the floating body (1), and the lower end of the air inlet head (6) is connected to an external fan room through a connecting air pipe (8).

4. The method for controlling diffuse cyanobacteria bloom in local waters of a water intake according to claim 1, characterized in that: The nano titanium dioxide powder is prepared specifically by first mixing isopropyl alcohol and tetrabutyl titanate to obtain solution A, then dissolving glacial acetic acid in deionized water and mixing to obtain solution B, then slowly dropping solution B into solution A and rapidly stirring with a magnetic stirrer to form a sol, and finally drying and calcining the sol to obtain the nano titanium dioxide powder.

5. The method for controlling diffuse cyanobacteria bloom in local waters of a water intake according to claim 4, characterized in that: The mass ratio of isopropanol to tetrabutyl titanate is 2:

1. When the sol is dried, it is first naturally air-dried for 30-40 minutes, and then placed in an oven at 105° C. for 2-3 hours to obtain a dry gel. Finally, the dry gel is nano-grinded to obtain a nano powder, which is then placed in a muffle furnace and calcined at 700-900° C. for 2-3 hours to obtain a nano titanium dioxide powder.

6. The method for controlling diffuse cyanobacteria bloom in local waters of a water intake according to claim 1, characterized in that: In the step 2, the mixing mass ratio of nano titanium dioxide powder, resin, dispersant and stabilizer is 20-25:60-70:3-5:5-8, wherein the resin is silicone-modified acrylic resin, the dispersant is one of sodium pyrophosphate, sodium polyacrylate and potassium tripolyphosphate, and the stabilizer is one of reduced graphene oxide powder and mesoporous molecular sieve SBA15.

7. The method for controlling diffuse cyanobacteria bloom in local waters of a water intake according to claim 1, characterized in that: In the step three, the drying condition of the sunshade net after spraying is to stand it in a dry and ventilated environment for 8-12 hours. In the step four, when arranging the photocatalytic sunshade net, it is sunken to a depth of 0.8-1.2m below the water surface with the side sprayed with slurry facing up. The floating plant is one of water lily, rain lily and water lily.

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