Equipment for controlling cyanobacterial bloom in lake and reservoir

Abstract

The invention discloses equipment for controlling cyanobacterial bloom in lakes and reservoirs, which comprises a ship body, a suction device, a spraying device and an oxidation device, an electro-catalysis unit is arranged on the ship body, an anode of the electro-catalysis unit is made of a soluble metal material, and metal cations are released after the electro-catalysis unit is electrified; the suction device comprises a main pipe, a bottom mud suction pipe and a cation suction pipe, the bottom mud suction pipe and the cation suction pipe are connected to the main pipe, a self-sucking pump is connected to the main pipe, and the suction device is used for sucking bottom mud sediments at the bottom of a lake and a reservoir. Through cooperative use of bottom mud, electro-catalysis and advanced oxidation, flocculating settling of algae cells in water is enhanced, and the effect of purifying water is achieved. The settled algae mud is mixed with the oxidized bottom mud and the metal flocculant, so that the structure is compact, and the algae mud is not easy to suspend again. The bottom mud, electro-catalysis and oxidation are matched for use, so that not only is the algae control efficiency improved, but also the common problems of unstable effect and the like of a single technology are effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of water environment management and ecological restoration technology, and in particular to a device for controlling cyanobacterial blooms in lakes and reservoirs. Background Technology

[0002] Eutrophication of lakes leading to cyanobacterial blooms (excessive algal growth) is a global environmental problem. The occurrence of cyanobacterial blooms severely damages aquatic ecosystems, deteriorates drinking water quality, produces algal toxins, and can cause poisoning incidents in fish and livestock, even posing potential risks to human health. In the past two decades, large lakes in my country, such as Taihu Lake, Chaohu Lake, and Dianchi Lake, have frequently experienced cyanobacterial blooms, with water quality at times declining to below Grade V, and major incidents of water supply crises caused by cyanobacterial blooms occurring. Therefore, how to efficiently remove algae from water bodies and prevent secondary pollution is a key technical challenge in the management of lake blooms.

[0003] Currently, there are various methods for controlling and removing algae in lakes, but each has its limitations. Physical methods include blocking nutrient sources, diluting and changing water, mechanically removing algae, artificially circulating water, and dredging bottom sediment. These methods are often slow to take effect, costly, have limited efficiency in removing algae, and are difficult to eliminate algae at their root. Summary of the Invention

[0004] The purpose of this invention is to solve the problems mentioned in the background art regarding the existing methods for controlling and removing algae, which are slow to take effect, costly, have limited efficiency in removing algae, and are difficult to eliminate algae at their root.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A device for controlling cyanobacterial blooms in lakes and reservoirs includes a hull, a suction device, a spraying device, and an oxidation device. The hull is equipped with an electrocatalytic unit, whose anode is made of a soluble metal material and releases metal cations upon energization. The suction device includes a main pipe and sediment suction pipes and cation suction pipes connected to the main pipe. A self-priming pump is connected to the main pipe. The suction device suctions sediment from the bottom of the lake / reservoir and mixes it with the metal cation-rich water generated by the electrocatalytic unit, forming a mud-water mixture containing flocculants and sediment particles. The oxidation device is mounted on the hull and includes an electrochemical reaction device inserted into a reaction tube. The oxidation device performs ozonation or electrochemical oxidation treatment on the mud-water mixture to reduce algal activity and algal toxin content. The spraying device includes a reaction tube connected to the main pipe, and multiple spraying pipes in various directions are connected to the reaction tube. The spraying device sprays the oxidized mud-water mixture onto the surface algal bloom area, causing algal particles to flocculate and settle.

[0006] Preferably, the sediment mixture and the cationic water flow are mixed at a volume ratio of sediment:cationic water flow = 1:5 to 1:20 to form a mixed flow, the mixed flow having a hydraulic residence time of 5–60 s, and acting with at least one of ozone / persulfate / electrochemical oxidation to achieve algal cell inactivation and algal toxin pretreatment.

[0007] Preferably, the electrocatalytic unit includes a generator and an electrochemical device. The generator is electrically connected to the electrochemical device. The metal cations generated by the electrocatalytic unit act as flocculants, causing algal cells in the water to rapidly aggregate and settle.

[0008] Preferably, the hull has a channel connecting to the water area, and both the bottom sediment suction pipe and the cation suction pipe enter the water through the channel. A reel for winding the bottom sediment suction pipe is provided on the upper side of the channel.

[0009] Preferably, a filter head for filtering debris is fixed to the end of the bottom sediment suction pipe.

[0010] Preferably, the oxidation device further includes an air compressor and an electrochemical sterilizer, wherein the air compressor is connected to the electrochemical sterilizer and the electrochemical sterilizer is connected to the electrochemical reaction device.

[0011] Preferably, the bottom of the cation suction tube is positioned close to the electrochemical device.

[0012] Preferably, a material distribution device is provided at the stern of the hull, and the material distribution device includes a downwardly inclined guide plate.

[0013] Preferably, a row of spaced vertical rods is fixed on the guide plate, and a flow guide plate is fixed on the vertical rod.

[0014] Preferably, a flow guide groove is provided on the lower side of the electrochemical device, and the lower end of the cation suction tube is located in the flow guide groove.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes the lake's own bottom sediment resources and the metal cations released by soluble electrodes, eliminating the need for large amounts of exogenous chemical agents, thus reducing treatment costs. It can also be implemented in situ in the lake area, offering advantages such as ease of operation, high efficiency, and environmental friendliness.

[0016] This invention utilizes metal cations generated by electrocatalysis as flocculants to rapidly aggregate and settle algal cells in water; combined with bottom sediment spraying to enhance the flocculation effect, it can effectively remove various planktonic algae, including Microcystis aeruginosa and filamentous cyanobacteria, and improve water transparency.

[0017] This invention uses advanced oxidation technology to first inactivate and degrade algal toxins in algal cells, avoiding secondary pollution caused by cell rupture and release of toxins and nutrients after simple algal settling, thus ensuring water quality safety.

[0018] This invention extracts an appropriate amount of lake bottom sediment and uses it as a natural flocculant to spray back into the lake. This not only achieves the recycling of bottom sediment and reduces the input of external agents, but also treats algae and mud simultaneously, reducing endogenous pollution caused by the long-term accumulation of algal residues in the bottom sediment.

[0019] This invention, through the combined use of bottom sediment, electrocatalysis, and advanced oxidation, enhances the flocculation and sedimentation of algal cells in water, achieving water purification. The settled algal sludge, due to the incorporation of oxidized bottom sediment and metal flocculants, has a compact structure and is less prone to re-suspension. The combined use of bottom sediment, electrocatalysis, and oxidation not only improves algae control efficiency but also effectively avoids the instability often found with single technologies. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0022] Figure 2 This is a schematic diagram of the through-slot and electrochemical device of the present invention.

[0023] Figure 3 This is a schematic diagram of the flow guide groove of the present invention.

[0024] Figure 4 This is a schematic diagram of the suction device structure of the present invention.

[0025] Figure 5 This is a schematic diagram of the propeller of the present invention.

[0026] Figure 6 This is a schematic diagram of the electrochemical reaction device and the material dispensing device of the present invention.

[0027] Drawing number explanations: 1. Hull; 11. Channel; 12. Propeller; 2. Electrochemical device; 3. Suction device; 31. Main pipe; 32. Bottom sediment suction pipe; 33. Cation suction pipe; 34. Self-priming pump; 35. Filter head; 4. Spraying device; 41. Reaction pipe; 42. Spraying pipe; 5. Oxidation device; 51. Electrochemical reaction device; 52. Air compressor; 53. Electrochemical sterilizer; 6. Generator; 7. Drum; 71. Drive motor; 8. Material distribution device; 81. Guide plate; 82. Vertical rod; 83. Flow guide plate; 9. Flow channel. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings.

[0029] The following description is intended to disclose the invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious modifications will be apparent to those skilled in the art. The basic principles of the invention defined in the following description can be used in other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0030] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or position based on the orientation or positional relationship shown in the accompanying drawings. They are merely simplified descriptions for the convenience of describing this invention and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on this invention.

[0031] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0032] Please see Figures 1-6A device for controlling cyanobacterial blooms in lakes and reservoirs includes a hull 1, a suction device 3, a spraying device 4, and an oxidation device 5. The suction device 3, spraying device 4, and oxidation device 5 are all mounted on the hull 1. An electrocatalytic unit is mounted on the hull 1, with its anode made of a soluble metal material that releases metal cations upon energization. The electrocatalytic unit includes a generator 6 and an electrochemical device 2, with the generator 6 electrically connected to the electrochemical device 2. The anode material of the electrocatalytic unit is iron or aluminum, and the current density is controlled between 5–20 mA / cm². The ratio of bottom sediment suction to surface water is controlled between 1:5 and 1:20. The oxidation device 5 employs one or more combinations of ozone / persulfate / electrochemical oxidation. The lower side of the electrochemical device 2 is in contact with water and is used to generate cations in the water. Direct current is applied to the electrochemical device 2 to dissolve metal cations, such as Fe³⁺ or Al³⁺, from the anode. These cations hydrolyze in the water to form flocculants, rapidly neutralizing the surface charge of algal cells and causing them to aggregate.

[0033] The suction device 3 suctions bottom sediment from the lake and mixes it with the metal cation water generated by the electrocatalytic unit to form a mud-water mixture containing flocculant and bottom sediment particles. The suction device 3 includes a main pipe 31 and a bottom sediment suction pipe 32 and a cation suction pipe 33 connected to the main pipe 31. The bottom of the cation suction pipe 33 is located near the electrochemical device 2. A self-priming pump 34 is connected to the main pipe 31. A channel 11 connecting to the water area is opened on the hull 1, and both the bottom sediment suction pipe 32 and the cation suction pipe 33 enter the water through the channel 11. A filter head 35 for filtering debris is fixed to the end of the bottom sediment suction pipe 32. The bottom sediment suction pipe 32 pumps up some bottom sediment and bottom water from the lake bottom to form a bottom sediment slurry, which is then mixed with the water sucked up by the cation suction pipe 33.

[0034] To better extract cations, a flow channel 9 is provided on the lower side of the electrochemical device 2. The flow channel 9 is fixedly connected to the hull 1. The lower end of the cation suction pipe 33 is located in the flow channel 9. The metal cations generated by the electrochemical device 2 flow along the flow channel 9, which facilitates the extraction of cations by the cation suction pipe 33.

[0035] The spraying device 4 sprays the oxidized mud-water mixture onto the algal bloom area on the surface of the water body, causing the algal particles to flocculate and settle. The spraying device 4 includes a reaction pipe 41, which is connected to the main pipe 31. Multiple spraying pipes 42 are connected to the reaction pipe 41. The spraying direction of the spraying pipes 42 is different, which can increase the spraying range.

[0036] Oxidation device 5 employs one or more combinations of ozone / persulfate / electrochemical oxidation. It treats the mud-water mixture with ozone or electrochemical oxidation to reduce algal activity and algal toxin content. Oxidation device 5 includes an electrochemical reaction device 51 inserted into reaction tube 41. It also includes an air compressor 52 and an electrochemical sterilizer 53. The air compressor 52 is connected to the electrochemical sterilizer 53, and the electrochemical sterilizer 53 is connected to the electrochemical reaction device 51. The air compressor 52 is used for air intake, the electrochemical sterilizer 53 is the oxidation generator, and the electrochemical reaction device 51 is the treatment reactor; all three are used together for oxidation treatment. Oxidation device 5 treats the contents of reaction tube 41, for example, by introducing ozone gas, adding persulfate, or exposing them to UV photocatalytic reactions. The strong free radicals generated by oxidation can kill algal cells or cysts carried in the mud and destroy the structure of residual algal cells, while also partially oxidizing and decomposing the organic matter and algal toxins within the algal cells. After oxidation treatment, the algae in the bottom sediment have been deactivated or destroyed, and the toxicity of the pollutants they carry has been greatly reduced.

[0037] The vessel 1 has a bridge. During the movement of the vessel 1, the oxidized bottom sediment slurry mixes with the flocculated water rich in metal cations generated by electrocatalysis, forming a mud-water mixture. After being sprayed back into the algal bloom area of ​​the lake, on the one hand, the flocculated water rich in metal cations enhances the positive charge of the bottom sediment; on the other hand, the bottom sediment itself is rich in a large number of metal cations, and the introduction of external cation-rich flocculated water further enhances the flocculation performance of the bottom sediment. In addition, the bottom sediment particles, as a carrier, can further coagulate with the flocs, enhancing the strength and weight of the flocs and forming a coagulation aid effect.

[0038] The residual oxidant and sediment in the mixture further act on the algal cells in the lake water, achieving in-situ enhanced flocculation and secondary oxidation. The synergistic effect of the sediment and metal ions causes damaged algal cells to quickly settle to the bottom, removing algae from the water. Specifically, most algal cells are flocculated into larger particles and settle to the surface of the sediment. The settled algal sludge, due to the mixing of oxidized and stabilized sediment and metal flocculants, has a compact structure and is not easily resuspended. The dead algal cells are encapsulated and fixed, and their internal nutrients (such as phosphorus and nitrogen) are also sealed in the sludge, thus preventing subsequent endogenous pollution. This significantly improves water transparency and dissolved oxygen, achieving the effect of water purification.

[0039] The spraying method can be to use the ship-mounted spray pipe 42 to spray repeatedly in areas prone to algal blooms, ensuring that the mixture is fully mixed and in contact with the algae layer.

[0040] A reel 7 for winding the bottom sediment suction pipe 32 is provided on the upper side of the channel 11. A drive motor 71 is provided on one side of the reel 7, which is used to rotate the reel 7. When the reel 7 rotates, the shaft of the reel 7 is hollow, and the bottom sediment suction pipe 32 is connected to the shaft, which is also connected to the main pipe 31. Flocculated water enters the bottom sediment suction pipe 32, then enters the shaft, then enters the main pipe 31, and finally enters the reaction pipe 41. A rotating propeller 12 is provided in the middle of the rear side of the hull 1. During the propulsion of the hull 1, the propeller 12 will cause waves to appear behind the hull 1. The waves ensure that the sprayed bottom sediment particles and the metal flocculant come into full contact.

[0041] Furthermore, to better disperse the mud-water mixture, a material distribution device 8 is provided at the stern of the hull 1. The material distribution device 8 includes a downwardly inclined guide plate 81. The sprayed mixture falls onto the guide plate 81 and slides down the guide plate 81, eventually falling into the water in a curtain-like manner, making the mixture evenly distributed, facilitating the diffusion of the mixture, and promoting algal bloom flocculation. A row of spaced vertical rods 82 are fixed on the guide plate 81. The vertical rods 82 are fixedly connected to the guide plate 81 through the rod body. A flow guide plate 83 is fixed on the vertical rods 82. The flow guide plate 83 consists of two inclined plates. There are still vertical rods 82 on the lower side of the flow guide plate 83. The mixture moves to both sides along the flow guide plate 83, and with the help of the vertical rods 82, the bottom mud particles and the metal flocculant are in full contact.

[0042] To enable those skilled in the art to more clearly understand the technical effects of the present invention, the algae control effect is illustrated in the following specific embodiments. The standard for mild cyanobacterial blooms is an algae density of 1.0 × 10⁻⁶. 7 5.0 x 10⁻⁵ liters / liter 7 The density of cyanobacteria in a moderate bloom is 5.0 × 10⁶ / L. 7 1.0 x 10⁻⁶ units / liter – 1.0 x 10⁻⁶ 8 The density of cyanobacteria in severe cyanobacterial blooms is greater than 1.0 × 10⁶ / L. 8 per liter.

[0043] Example 1 Table 1. Algal density (mild algal bloom level) under different sediment concentrations and ozone concentrations. Table 1 shows the results of two treatment methods—adding bottom sediment alone and combining bottom sediment with ozone—under mild Microcystis bloom conditions. The results indicate that, with an initial algal density of 3.22 × 10⁻⁶, the treatment was more effective. 7 When the algae density is 1.13 × 10⁶ / L, simply adding bottom sediment can reduce the algae density to 1.13 × 10⁶ / L. 7 The concentration of algae in the sediment was 100 μg / L, indicating that the sediment itself has a certain algae control effect. Further introduction of ozone significantly enhanced this effect, and the algae density continued to decrease with increasing ozone dosage. When the ozone concentration reached 200 μg / g, the algae density dropped to 0.47 × 10⁻⁶. 7The algal density did not decrease significantly when the concentration was increased to 240 μg / g, indicating that there is a threshold for the enhancing effect of ozone, approximately 200 μg / g. In summary, sediment alone can partially reduce algal blooms, while the introduction of ozone has a significant synergistic effect, which can greatly improve the algal control efficiency of sediment.

[0044] Example 2 Table 2. Algal density (severe algal bloom level) under different sediment concentrations and ozone concentrations. Table 2 shows the algae control effect of the same sediment concentration combined with different ozone dosages under high algae concentration conditions. The results show that under high algae concentration conditions, the initial algae density was 2.65 × 10⁻⁶. 8 At a density of [number] algae per liter, the algae density decreased to 1.82 × 10⁻⁶ after adding only bottom sediment. 8 The concentration of algae per liter indicates that the sediment still has a certain settling effect. With increasing ozone concentration, the algal density further decreased significantly: from 80 μg / g to 1.15 × 10⁻⁶. 8 The concentration of [amount] / L decreased further to 0.20 × 10⁻⁶ at 160 μg / g. 8 The results showed that under high algal load conditions, sediment and ozone had a significant synergistic effect, with ozone having a more prominent effect on algal control.

[0045] Example 3 Table 3. Algal density (severe algal bloom level) at different times under different iron and aluminum concentrations. Table 3 shows the algae control effects of sediment alone and the auxiliary effect of iron / aluminum ions generated by electrocatalysis. The results show that, without electrocatalysis, the algae density decreased by only 2.88 × 10⁻⁶ within 300 minutes. 8 The number of cells / liter slowly decreased to 2.00 × 10⁻⁶. 8 The algae density was significantly reduced by the addition of metal ions generated by electrocatalysis, with the algae control effect increasing with increasing iron or aluminum ion concentration: for example, under Fe concentrations of 200 μg / L, the algae density decreased to 0.09 × 10⁻⁶ within 200 minutes. 8 The algal density decreased to near zero within 300 minutes under an Al concentration of 500 μg / L. This demonstrates that the iron and aluminum ions generated by electrocatalysis promoted algal flocculation and sedimentation, forming a synergistic effect with the sediment particles.

[0046] Compared with existing technologies, this invention achieves better results through the organic coupling of sediment, electrocatalysis, and oxidation. The experimental results in Tables 1-3 show that the combined use of sediment, electrocatalysis, and oxidation proposed in this invention is more effective in controlling algae than any single method. Specifically, while adding sediment alone can reduce algae density, the effect is limited. Introducing oxidation methods such as ozone into the sediment system significantly enhances sedimentation efficiency and exhibits a clear threshold characteristic under medium-to-high concentration algal bloom conditions, resulting in stable and reliable algae control. Simultaneously, the synergistic use of iron and aluminum cations generated by electrocatalysis with the sediment can significantly accelerate the sedimentation rate of algal cells, with this acceleration further increasing with increasing metal ion concentration. These results demonstrate that the combination of sediment, electrocatalysis, and oxidation not only improves algae control efficiency but also effectively avoids the common problems associated with single methods, achieving simultaneous removal of cyanobacterial cells and algal toxins, and reducing the risk of secondary pollution.

[0047] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been shown and explained in the embodiments, and any variations or modifications may be made to the implementation of the present invention without departing from the stated principles.

Claims

1. A device for controlling cyanobacterial blooms in a lake or reservoir, characterized in that, The utility model relates to a ship for treating water body, which comprises: a ship body (1) provided with an electro-catalytic unit, the anode of which is made of a soluble metal material and releases metal cations when electrified; a suction device (3) comprising a main pipe (31), a bottom mud suction pipe (32) and a cation suction pipe (33) connected to the main pipe (31), a self-suction pump (34) being connected to the main pipe (31), the suction device (3) sucking the bottom mud deposits at the bottom of a lake or reservoir and mixing with the metal cation flow generated by the electro-catalytic unit to form a mud-water mixture containing flocculants and bottom mud particles; an oxidation device (5) provided on the ship body (1), the oxidation device (5) comprising an electrochemical reaction device (51) inserted into a reaction pipe (41), the oxidation device (5) performing ozonation or electrochemical oxidation treatment on the mud-water mixture to reduce the activity of algae and the content of algal toxins; a spraying device (4) comprising a reaction pipe (41) in communication with the main pipe (31), the reaction pipe (41) being provided with a plurality of spraying pipes (42) in different directions, the spraying device (4) spraying the mud-water mixture after the oxidation treatment to the surface layer of the water body in the algal bloom area to cause flocculation and sedimentation of the algae particles.

2. The device for controlling cyanobacterial blooms in a lake or reservoir according to claim 1, characterized in that: The bottom mud mixture is mixed with the cation flow at a volume ratio of 1:5 to 1:20 to form a mixture flow, the mixture flow has a hydraulic retention time of 5-60 s, and at least one of ozone / persulfate / electrochemical oxidation is used to achieve algal cell inactivation and algal toxin pretreatment.

3. The device for controlling cyanobacterial blooms in a lake or reservoir according to claim 1, characterized in that: The ship body (1) is provided with a generator (6) electrically connected to the electrochemical device (2). The electro-catalytic unit comprises the generator (6) and the electrochemical device (2), and the generator (6) is connected to the electrochemical device (2).

4. The device for controlling cyanobacterial blooms in a lake or reservoir according to claim 3, characterized in that: The ship body (1) is provided with a through groove (11) connected to the water area, the bottom mud suction pipe (32) and the cation suction pipe (33) enter the water through the through groove (11), and the through groove (11) is provided with a winding drum (7) for winding the bottom mud suction pipe (32) on the upper side.

5. The device for controlling cyanobacterial blooms in a lake or reservoir according to claim 1, characterized in that: The end of the bottom mud suction pipe (32) is fixed with a filter head (35) for filtering sundries.

6. The device for controlling cyanobacterial blooms in a lake or reservoir according to claim 1, characterized in that: The oxidation device (5) further comprises an air compressor (52) and an electrochemical sterilizer (53), the air compressor (52) is connected to the electrochemical sterilizer (53), and the electrochemical sterilizer (53) is connected to the electrochemical reaction device (51).

7. The device for controlling cyanobacterial blooms in a lake or reservoir according to claim 1, characterized in that: The bottom of the cation suction pipe (33) is arranged close to the electrochemical device (2).

8. The device for controlling cyanobacterial blooms in a lake or reservoir according to claim 1, characterized in that: The ship body (1) is provided with a distribution device (8) at the tail, the distribution device (8) comprising an inclined downward guide plate (81).

9. The device for controlling cyanobacterial blooms in a lake or reservoir according to claim 8, characterized in that: A row of vertical rods (82) are fixed on the guide plate (81) at intervals, and a flow guide plate (83) is fixed on the vertical rods (82).

10. The apparatus for controlling cyanobacterial blooms in a lake or reservoir according to claim 1, characterized in that: The electrochemical device (2) is provided with a flow guide groove (9) on the lower side, and the lower end of the cation suction pipe (33) is located in the flow guide groove (9).

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