Tidal flotation tank for treating marine micro-plastic pollution

Abstract

The invention discloses a tidal flotation tank for treating marine micro-plastic pollution, and relates to the technical field of tidal flotation ponds.The tidal flotation tank is provided with an outer dam, an inner dam, aeration equipment and an overflow weir, the high and low tide alternation phenomenon of seawater tides is utilized, and when rising tide begins, the aeration equipment and the overflow weir are separated; seawater and pollutants in the seawater are collected to a pollution remediation area through a one-way inlet culvert, then in the pollution remediation area, an inflator pump is driven by a wind driven generator to start to inflate, and under the action of hydrophobic attraction, micro-plastics and micro-nano bubbles are combined to form an aggregate with the density smaller than that of water, so that the aggregate automatically floats upwards; the micro-plastic pollutants floating on the surface of water are collected into the overflow weir to be cleaned, and the treated seawater is discharged into the ocean again through the one-way outlet culvert during ebb tide, so that the tedious process of pumping and draining water is avoided, and the water body of the coastal zone is periodically and intensively collected and treated.

Description

Technical Field

[0001] This invention relates to the field of tidal flotation technology, specifically a tidal flotation tank for treating marine microplastic pollution. Background Technology

[0002] Marine microplastic pollution is one of the most prominent problems facing the global marine ecosystem in recent years. Microplastics generally refer to plastic particles with a diameter of less than 5 millimeters, originating from sources such as the aging and breakage of plastic products, the shedding of synthetic fibers, and industrial raw material leaks. These particles exhibit long-term stability in the ocean, readily adsorbing organic pollutants and heavy metals, and accumulating through the food chain, posing a potential threat to marine ecosystems and human health. Currently, the remediation of marine plastic pollution mainly focuses on the cleanup of macroscopic plastic waste. Common technologies include manual netting, marine garbage bins, floating interception belts, and mechanical cleanup vessels. These devices typically rely on physical screening, interception, or mechanical recycling principles, effectively collecting large pieces of plastic waste floating on the water surface. However, existing methods are ineffective for microplastics with smaller particle sizes, densities close to or slightly lower than seawater, and suspended below the surface.

[0003] Existing mechanical or filtration devices have the following main problems: (1) Limited applicable particle size range. Microplastic particles are small in size and have varying distribution depths, making them difficult to effectively retain through mechanical sieving or netting. (2) Low operating efficiency and high operating costs. Most devices require power drive or manual operation, are complex to maintain, have high energy consumption, and are not suitable for large-scale continuous operation; (3) Susceptible to interference from the marine environment. Tides, currents, waves, and other factors can significantly affect the stability of equipment operation, leading to fluctuations in cleaning efficiency; (4) In-situ remediation is not possible. Currently, most methods are centralized collection or shore-based treatment, and there is a lack of in-situ remediation systems that can be deployed directly in marine ranches, intertidal zones and other areas for a long period of time.

[0004] In recent years, researchers have attempted to apply the flotation separation principle from mineral processing to microplastic removal. This method utilizes the hydrophobicity of microplastic surfaces, causing air bubbles to adhere to the surface of microplastic particles, forming a complex with a density less than water. This complex then floats to the surface, achieving enrichment and separation. Compared to traditional physical filtration, flotation can remove a wider range of microplastic particles in a shorter time and exhibits a degree of selectivity.

[0005] However, existing microplastic flotation technology is still mainly limited to the laboratory or small-scale device stage, and has the following limitations: (1) Experimental apparatus usually relies on mechanical stirring or air pumps for gas supply, which makes it difficult to operate stably in marine field environments; (2) The system is small in size and cannot handle large volumes of seawater inflow and outflow, nor can it adapt to the water level difference caused by tidal changes; (3) High external energy requirements, which is not conducive to long-term, unattended operation; (4) The contact time and floating path between the bubbles and microplastics are greatly affected by external disturbances, resulting in unstable separation efficiency.

[0006] In summary, existing marine microplastic remediation technologies generally suffer from limited applicability, high energy consumption, difficult maintenance, and a lack of in-situ and engineering application capabilities. Particularly in areas such as the intertidal zone or marine ranches, there is a lack of in-situ microplastic remediation devices that can utilize natural tidal energy, achieve continuous circulation, and possess self-driving and highly efficient separation capabilities. Summary of the Invention

[0007] This invention provides a tidal flotation tank for treating marine microplastic pollution, aiming to solve the aforementioned problems.

[0008] To achieve the above objectives, the present invention provides a tidal flotation tank for treating marine microplastic pollution, comprising: The outer dam is equipped with several inlet culverts and several outlet culverts; The inner dam connects to both ends of the outer dam to form a pollution remediation zone, allowing seawater to enter the pollution remediation zone through the inlet culvert and flow out of the pollution remediation zone through the outlet culvert. Aeration equipment is installed at the bottom of the contaminated remediation zone to aerate the zone. An overflow weir, located on the inner dam and extending to both ends of the inner dam, collects microplastic pollutants overflowing from the contamination remediation area and filters the seawater through a screen before draining it out of the inner dam.

[0009] Preferably, the bottom elevation of the inlet culvert is higher than the average high tide level of the tidal flow; the bottom elevation of the outlet culvert is higher than the average low tide level of the tidal flow; the pollution remediation zone has an inclined bottom surface, and the inlet and outlet culverts are inclinedly located on the outer dam and parallel to the inclined bottom surface.

[0010] The inlet culvert has a structure that is wider on the outside and narrower on the inside, while the outlet culvert has a structure that is wider on the inside and narrower on the outside. One-way flow valves, which are either check valves or one-way valves, are installed inside the inlet culvert and outside the outlet culvert.

[0011] Preferably, the aeration equipment includes multiple air pipes arranged in a fan shape at the bottom of the contaminated remediation area, and a U-shaped pipe for connecting an air pump or air source. The U-shaped pipe is connected to the air pipes, and multiple nozzles are installed on the air pipes and the U-shaped pipe. It also includes a wind turbine generator for providing power to the air pump.

[0012] Preferably, the overflow weir located on the inner dam has a straight structure, and the filter screen is inclined on both sides of the overflow weir.

[0013] Preferably, it also includes a bottom net, which consists of multiple pieces. The multiple bottom net pieces are detachably installed on the overflow weir and maintain a certain distance from the bottom of the overflow weir, so that seawater overflows into the overflow weir and flows towards the filter screen through the space under the bottom net.

[0014] Preferably, a U-shaped overflow weir is provided on the upper part of the outer dam, and filter screens are installed at both ends of the U-shaped overflow weir; a bottom mesh is installed inside the U-shaped overflow weir. The height of the U-shaped overflow weir is higher than that of the straight overflow weir, so as to handle the overflow in the pollution remediation area when the water level is high by setting up the U-shaped overflow weir.

[0015] Preferably, the ends of the multiple tracheas are connected by a C-shaped tube; it also includes a horizontal tube connected to the C-shaped tube and the U-shaped tube.

[0016] Preferably, the system also includes a liquid level sensor, which is installed on the inner dam and electrically connected to an air pump or air source. A float can be used instead of a liquid level sensor; when the water level in the contaminated remediation area reaches a certain height, it pushes the float to trigger the air pump's operating circuit, causing the nozzles on the air pipe and U-shaped tube to perform aeration.

[0017] Compared with existing technologies, it has the following beneficial effects: 1. Self-driving and low energy consumption: It uses tidal energy to achieve automatic water inflow and outflow, without the need for an external pumping system.

[0018] 2. In-situ and continuous management: It can be deployed in marine ranches or intertidal zones for a long time to achieve continuous operation.

[0019] 3. Enhanced flotation mechanism: By enhancing the hydrophobicity of microplastics through feed nutrients and natural organic matter, separation efficiency is significantly improved.

[0020] 4. Good ecological compatibility: No chemical agents are added, and the system materials and operation are safe for the marine ecosystem.

[0021] 5. High scalability: Simple structure, easy maintenance, and the scale and operation mode can be flexibly adjusted according to the marine conditions. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only preferred embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the tidal flotation tank for treating marine microplastic pollution according to the present invention; Figure 2This is a cross-sectional view of the tidal flotation tank for treating marine microplastic pollution according to the present invention. Figure 3 This is a schematic diagram of the tidal flotation tank for treating marine microplastic pollution according to the present invention; Figure 4 This is a side view of the tidal flotation tank for treating marine microplastic pollution according to the present invention; Figure 5 for Figure 3 Enlarged view of point A in the middle; Figure 6 This is a schematic diagram of the rear of the tidal flotation tank for treating marine microplastic pollution according to the present invention. Figure 7 This is a cross-sectional view of the tidal flotation tank for treating marine microplastic pollution according to the present invention. Figure 8 for Figure 7 Enlarged view of point B in the middle; Figure 9 This is a schematic diagram of the aeration device of the present invention; Figure 10 This is a schematic diagram of another embodiment of the aeration device of the present invention; Figure 11 This is a schematic diagram of the filter screen and bottom screen of the present invention; Figure 12 for Figure 11 Enlarged view of point C in the middle; Figure 13 A graph showing the flotation removal efficiency of microplastics of different particle sizes; Figure 14 A graph showing the stability of marine micro-nano bubbles in a flotation cell; Figure 15 This is a graph showing the stability of marine micro-nano bubbles in a flotation cell.

[0024] Attached diagram labels: 1-Outer dam; 11-Inlet culvert; 12-Outlet culvert; 2-Inner Dam; 3-Aeration equipment; 31-Air pipe; 32-U-shaped pipe; 33-Air pump; 34-C-shaped pipe; 35-Horizontal pipe; 4- Overflow weir; 5-Pollution remediation area; 51-Sloping bottom surface; 6-Valve components; 7-Wind turbine; 8-Filter screen; 9-Bottom net. Detailed Implementation To better understand the structure, functional features, and advantages of the present invention, preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings: Example 1: like Figures 1 to 8 As shown, the present invention provides a tidal flotation tank for treating marine microplastic pollution, comprising: The outer dam 1 is equipped with several inlet culverts 11 and several outlet culverts 12, with five inlet culverts 11 and three outlet culverts 12; The inner dam 2 is connected to both ends of the outer dam 1 to form a pollution remediation zone 5, allowing seawater to enter the pollution remediation zone 5 through the inlet culvert 11 and flow out of the pollution remediation zone 5 through the outlet culvert 12; the outer dam 1 is lower than the inner dam 2. Aeration equipment 3 is installed at the bottom of the pollution remediation zone 5 to aerate the pollution remediation zone 5; Overflow weir 4 is set on outer dam 1 and extends to both ends of inner dam 2 to collect microplastic pollutants overflowing from pollution remediation area 5 and filter them through filter screen 8 to discharge seawater into inner dam 2.

[0025] Specifically, the outer dam 1 is a concrete structure that serves as the outer boundary of the facility. Its outer side is subject to tidal flow, while its inner side, together with the inner dam 2, encloses the pollution remediation zone 5. The crest elevation of the outer dam 1 is slightly lower than that of the inner dam 2 to facilitate the formation of a water level difference during tidal rise and fall.

[0026] The inner dam 2 is a concrete structure that forms the inner boundary of the pollution remediation zone 5. Its crest elevation is slightly higher than that of the outer dam 1, providing an installation foundation for the overflow weir 4 and working with the outer dam 1 to maintain a stable water level.

[0027] See Figure 2 and Figure 7 The bottom elevation of the inlet culvert 11 is higher than the average high tide level of the tidal flow; the bottom elevation of the outlet culvert 12 is higher than the average low tide level of the tidal flow; the pollution remediation zone 5 has an inclined bottom surface 51, and the inlet culvert 11 and the outlet culvert 12 are inclined on the outer dam 1 and parallel to the inclined bottom surface 51.

[0028] See Figure 3 and Figure 7The inlet culvert 11 has a structure that is wider on the outside and narrower on the inside, while the outlet culvert 12 has a structure that is wider on the inside and narrower on the outside. One-way flow valves 6 are installed inside the inlet culvert 11 and outside the outlet culvert 12. These valves 6 are either one-way valves or check valves, ensuring unidirectional inflow and outflow of seawater. The valves 6 of this invention can adopt an opening and closing plate structure, hinged inside the inlet culvert 11 and at the outlet culvert 12. Because the two sides of the outer dam 1 are inclined, the opening and closing plate structure can automatically close under gravity, thus achieving unidirectional flow. This opening and closing plate structure allows for unidirectional water intake into the inlet culvert 11. Under the action of water pressure and the inclined surface of the outer dam 1, it can unidirectionally restrict the flow of seawater within the pollution remediation zone 5, preventing it from flowing out of the inlet culvert 11. Because the seawater outside the outer dam 1 is always higher than the outlet culvert 12, it is always closed to prevent the pollution remediation zone 5 from flowing out of the outlet culvert 12. When the seawater level outside the outer dam 1 is lower than the outlet culvert 12, the pollution remediation zone 5 is flowed by the inclined bottom surface 51 to open the opening and closing plate structure for drainage.

[0029] See Figure 1 and Figure 9 The aeration device 3 includes multiple air pipes 31 arranged in a fan shape at the bottom of the pollution remediation zone 5, and a U-shaped pipe 32 for connecting the air pump 33 or the air source. The U-shaped pipe 32 is connected to the air pipes 31. Multiple nozzles are provided on the air pipes 31 and the U-shaped pipe 32. The air pump 33 provides micro-nano bubbles to the flotation tank remediation zone. These bubbles can adhere to the surface of microplastics in seawater and form aggregates with a density less than that of water, thus easily floating to the surface for water remediation.

[0030] See Figure 1 It also includes a wind turbine 7 for providing power to the air pump 33. The wind turbine 7 provides power to the air pump 33 or the gas source, so that gas is supplied to the air pipe 31 through the U-shaped pipe 32 and aerated into the seawater in the pollution remediation area 5 through multiple nozzles. Furthermore, both ends of the U-shaped pipe 32 are connected to the gas source.

[0031] Specifically, the air pump 33 can be electrically driven, powered by the wind turbine 7, to provide a stable airflow. The output flow rate and pressure of the air pump 33 are adjustable to adapt to different water depths and pollution concentrations.

[0032] U-shaped pipe 32: Made of high-polymer anti-corrosion pipe material, it is attached to the inclined bottom surface 51 of the contaminated remediation area 5 and is used to transport compressed air.

[0033] Trachea 31: Distributed in a fan shape on the inclined bottom surface 51 of the contaminated remediation area 5, used for pressure stabilization and flow diversion, and can be equipped with flow restriction holes or baffles to balance the airflow of each trachea 31.

[0034] Nozzle: Employing a microporous gas distribution device located at the end of gas pipe 31 and U-shaped pipe 32 or at the bottom of the pool, it includes structures such as ceramic microporous plates, flexible porous membranes, or micro-jet heads. This device disperses the gas into microbubbles with a diameter of 50–300 μm through physical segmentation. During their ascent, these micro- and nanobubbles fully contact and adhere to the microplastic particles, rising together to the water surface, achieving highly efficient flotation enrichment.

[0035] The aeration equipment can automatically start and stop according to tidal changes, automatically starting aeration during high tide and shutting off during low tide, so as to minimize energy consumption and achieve long-term autonomous operation.

[0036] Furthermore, the microporous gas distribution device adopts a zoned gas distribution mode, that is, multiple independently controlled gas distribution units are arranged at the bottom of the flotation tank along the water flow direction. The gas volume and pressure of each zone are adjusted by a programmable control unit (PLC) to achieve gradient control of micro-nano bubble concentration, thereby improving the utilization rate of micro-nano bubbles and flotation efficiency.

[0037] This invention utilizes the alternating high and low tide phenomena of seawater by setting up an outer dam 1, an inner dam 2, an aeration device 3, and an overflow weir 4. When the tide begins to rise, seawater and pollutants in the seawater are collected through a one-way inlet culvert 11 to a pollution remediation area 5. In the pollution remediation area 5, a wind turbine 7 drives an air pump 33 to start aeration. Under the action of hydrophobic attraction, microplastics and micro-nano bubbles combine to form aggregates with a density less than water, thus automatically floating to the surface. Subsequently, the microplastic pollutants floating on the water surface are collected into the overflow weir 4 for cleaning. When the tide recedes, the treated seawater is discharged back into the ocean through a one-way outlet culvert 12, eliminating the cumbersome process of pumping and draining water, thereby achieving periodic centralized collection and treatment of coastal waters.

[0038] The marine tidal flotation tank of this invention can be deployed in coastal areas. Seawater contains algae and their secreted extracellular polymers, such as polysaccharides, as well as oil pollutants leaked from ships. These substances can combine with the surface of microplastics, enhancing the hydrophobicity of microplastics and promoting aggregation, thereby improving flotation efficiency. On this basis, the synergistic removal of microplastics and other pollutants can be achieved. In addition, fish feed can be added to the tidal flotation tank during water storage. The nutrients such as oil and protein in the feed act as "collectors," changing the hydrophilicity and hydrophobicity of the microplastic surface, allowing the microplastics to better combine with micro-nano bubbles, achieving a highly efficient removal effect. It can also simultaneously serve the construction of marine ranches, improve the marine ecological environment, and ultimately form a comprehensive system integrating pollution control and fishery resource enhancement and conservation.

[0039] Example 2: As another embodiment of the present invention, such as Figure 5As shown, the overflow weir 4 located on the inner dam 2 has a straight structure, and the filter screen 8 is inclined on both sides of the overflow weir 4. The seawater overflowing from the pollution remediation area 5 enters the overflow weir 4 with a straight structure and flows twice along the axial direction, thus flowing out of the overflow weir 4 through the filter screen 8 on the inclined surface on both sides of the inner dam 2, that is, the filter screen 8 on the openings on both sides of the overflow weir 4.

[0040] See Figure 8 , Figure 11 and Figure 12 It also includes a bottom net 9, which consists of multiple pieces. These multiple bottom net pieces 9 are detachably installed on the overflow weir 4 and maintain a certain distance from the bottom of the overflow weir 4, allowing seawater to overflow into the overflow weir 4 and flow towards the filter screen 8 through the space below the bottom net 9.

[0041] Example 3: As another embodiment of the present invention, such as Figure 7 and Figure 12 As shown, a U-shaped overflow weir 4 is installed on the upper part of the outer dam 1. Filter screens 8 are installed at both ends of the U-shaped overflow weir 4. A bottom mesh 9 is installed inside the U-shaped overflow weir 4. The height of the U-shaped overflow weir 4 is higher than that of the straight overflow weir 4, so that the overflow from the pollution remediation zone 5 at high water levels can be filtered through the U-shaped overflow weir 4 on the outer dam 1 when the water level in the pollution remediation zone 5 is higher than that of the straight overflow weir 4 on the inner dam 2.

[0042] Example 4: As another embodiment of the present invention, such as Figure 10 As shown, the ends of multiple air pipes 31 are connected by C-shaped pipes 34; it also includes a horizontal pipe 35, which is connected to the C-shaped pipe 34 and the U-shaped pipe 32, and multiple nozzles are also provided on the horizontal pipe 35. This embodiment optimizes the air path by setting up the C-shaped pipe 34 and the horizontal pipe 35 to improve the uniformity of aeration at various locations within the contaminated remediation zone 5.

[0043] In this embodiment, multiple water turbine agitators are installed inside the outer dam 1 to aerate and agitate the seawater in the pollution remediation zone 5. The water turbine agitators are installed at the inlet culvert 11. When seawater enters the pollution remediation zone 5 from the inlet culvert 11, it drives the water turbines to rotate. The water turbine agitators are connected by a transmission chain or transmission mechanism so that multiple water turbine agitators installed at the inlet culvert 11 can work synchronously.

[0044] Furthermore, it also includes a liquid level sensor, which is installed on the inner dam 2 and electrically connected to the air pump 33 or an air source. The liquid level sensor can be replaced by a float. When the water level in the pollution remediation area reaches a certain height, it pushes the float to trigger the working circuit of the air pump 33, causing the nozzles on the air pipe 31 and U-shaped pipe 32 to perform aeration, which can effectively prevent the aeration equipment from aerating for a long time.

[0045] The working principle of this invention is as follows: By utilizing the alternating high and low tide phenomenon of seawater, when the tide begins to rise, seawater and pollutants in the seawater are collected into the pollution remediation area 5 through the one-way inlet culvert 11. Then, in the pollution remediation area 5, the air pump 33 driven by the wind turbine 7 starts to inflate the water. Under the action of hydrophobic attraction, microplastics and micro-nano bubbles combine to form aggregates with a density less than water, thus automatically floating to the surface. Subsequently, the microplastic pollutants floating on the water surface are collected into the overflow weir 4 for cleaning. When the tide recedes, the treated seawater is discharged back into the ocean through the one-way outlet culvert 12, eliminating the cumbersome process of pumping and draining water, thereby realizing the periodic centralized collection and treatment of coastal waters.

[0046] Compared to ordinary millimeter-sized large bubbles, micro- and nano-bubbles (0.1-100 μm in diameter) possess unique physicochemical properties due to their extremely small size, including a large specific surface area, an extremely long residence time in water, and a high interfacial zeta potential (negatively charged surface). These properties elevate them from simple aeration tools to highly efficient process enhancement methods: the huge specific surface area provides ample space for gas mass transfer and interfacial reactions, while the slow rise velocity and surface charge effect significantly enhance their collision and adsorption capacity with pollutants. Based on this, in enhanced air flotation processes, micro- and nano-bubbles can effectively capture and float difficult-to-settle microplastic particles in water using their superior mass transfer efficiency and interfacial reactivity, thereby significantly improving removal efficiency.

[0047] like Figure 13 The figure shows the flotation behavior of microplastics with different particle sizes, for comparison. Figure 13 a and Figure 13 b indicates that under the removal conditions of conventional aeration technology (such as...) Figure 13 a) The removal efficiency of microplastics is relatively low (≤28%), while in tidal flotation tanks, the removal efficiency of microplastics of various particle sizes is improved (e.g., Figure 13 (b) Among them, the flotation efficiency of microplastics with a particle size of 38-48 μm exceeded 80%, and the flotation efficiency of 48-72 μm was the highest, reaching 95.9%. For all particle sizes of microplastics, the removal rate of microplastics was significantly improved after adding fish feed nutrients and natural organic matter to the flotation tank, with the best flotation effect observed at a concentration of 28.5 g / m³. This result indicates that adding fish feed nutrients to the flotation tank can enhance the hydrophobicity of microplastics, which is beneficial to improving the separation efficiency of microplastics in the flotation tank.

[0048] like Figure 14 As shown, in a pure water environment (0 mM), the particle size of micro-nano bubbles is generally large (3.0-3.5 μm), while in a real seawater environment, the ionic strength is very high and the cation composition is complex (Na... + Mg 2+ K + Ca 2+ (Mainly) In this environment, the particle size of micro-nano bubbles will further decrease and tend to stabilize, making it easier to form a micro-nano bubble community with more uniform size and higher stability, which is conducive to more efficient capture of hydrophobic microplastics and improve flotation separation efficiency.

[0049] like Figure 15 As shown, in the marine environment (Na) + The concentration is generally between 300-500 mM), and the size and stability of micro / nano bubbles are significantly affected by Na. + Regulation of high concentrations of Na in seawater environment + This process strongly compresses the electric double layer between microplastics and micro / nanobubbles, resulting in smaller micro / nanobubbles that are more prone to aggregation. This is beneficial for flotation technology to capture microplastic particles, thereby improving the removal rate.

[0050] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technology of the present invention without departing from the scope of the present invention are within the protection scope of the present invention.

Claims

1. A tidal floatation cell for remediation of marine microplastic pollution, characterized in that, include: The outer dam (1) is equipped with several inlet culverts (11) and several outlet culverts (12). The inner dam (2) is connected to both ends of the outer dam (1) to form a pollution remediation zone (5), allowing seawater to enter the pollution remediation zone (5) through the inlet culvert (11) and flow out of the pollution remediation zone (5) through the outlet culvert (12). An aeration device (3) is installed at the bottom of the pollution remediation zone (5) to aerate the pollution remediation zone (5); An overflow weir (4) is set on the inner dam (2) and extends to both ends of the inner dam (2) to collect microplastic pollutants overflowing from the pollution remediation area (5) and filter them through a filter screen (8) to discharge seawater out of the inner dam (2).

2. The tidal flotation tank for treating marine microplastic pollution according to claim 1, characterized in that, The bottom elevation of the inlet culvert (11) is higher than the average high tide level of the tidal flow; the bottom elevation of the outlet culvert (12) is higher than the average low tide level of the tidal flow; the pollution remediation area (5) is an inclined bottom surface (51), and the inlet culvert (11) and the outlet culvert (12) are inclined on the outer dam (1) and parallel to the inclined bottom surface (51).

3. The tidal flotation tank for treating marine microplastic pollution according to claim 2, characterized in that, The inlet culvert (11) has a structure that is wider on the outside and narrower on the inside, and the outlet culvert (12) has a structure that is wider on the inside and narrower on the outside. A one-way valve (6) is provided inside the inlet culvert (11) and outside the outlet culvert (12). The valve (6) is a one-way valve or a check valve.

4. The tidal flotation tank for treating marine microplastic pollution according to claim 3, characterized in that, The aeration device (3) includes multiple air pipes (31) arranged in a fan shape at the bottom of the pollution remediation area (5), and a U-shaped pipe (32) for connecting an air pump (33) or an air source. The U-shaped pipe (32) is connected to the air pipes (31), and multiple nozzles are provided on the air pipes (31) and the U-shaped pipe (32).

5. The tidal flotation tank for treating marine microplastic pollution according to claim 4, characterized in that, It also includes a wind turbine (7) for providing power to the air pump (33).

6. The tidal flotation tank for treating marine microplastic pollution according to claim 1 or 4, characterized in that, The overflow weir (4) located on the inner dam (2) has a straight structure, and the filter screen (8) is inclined on both sides of the overflow weir (4).

7. The tidal flotation tank for treating marine microplastic pollution according to claim 5, characterized in that, It also includes a bottom net (9), which consists of multiple pieces. The multiple pieces of the bottom net (9) are detachably mounted on the overflow weir (4) and maintain a certain distance from the bottom of the overflow weir (4), so that seawater overflows into the overflow weir (4) and flows towards the filter screen (8) through the lower space of the bottom net (9).

8. The tidal flotation tank for treating marine microplastic pollution according to claim 7, characterized in that, The outer dam (1) is provided with an overflow weir (4) in a U-shape at the upper part, and the filter screen (8) is provided at both ends of the overflow weir (4) in a U-shape; the bottom net (9) is provided inside the overflow weir (4) in a U-shape.

9. The tidal flotation tank for treating marine microplastic pollution according to claim 4, characterized in that, The ends of the multiple tracheas (31) are connected by a C-tube (34); the trachea also includes a horizontal tube (35) connected to the C-tube (34) and the U-tube (32).

10. The tidal flotation tank for treating marine microplastic pollution according to claim 4 or 9, characterized in that, It also includes a liquid level sensor, which is installed on the inner dam (2) and is electrically connected to the air pump (33) or air source.

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