Circulating aquaculture water treatment system based on ozone micro-nano bubbles

Abstract

The utility model relates to a circulating aquaculture water treatment system based on ozone micro-nano bubbles. The method is suitable for the technical field of aquaculture and environmental engineering. The technical problem to be solved by the utility model is to provide the circulating aquaculture water treatment system based on the ozone micro-nano bubbles. According to the technical scheme, the device comprises a contact reaction tank used for fully mixing and dissolving aquaculture tail water and micro-nano bubble water through a micro-nano bubble water distribution pipe at the bottom of the contact reaction tank to form mixed and dissolved water, and ozone micro-nano bubbles are contained in the micro-nano bubble water; the standing reaction tank is used for receiving the miscible water output by the contact reaction tank and outputting the miscible water after a certain time; the aeration removal tank is used for receiving the miscible water output by the standing reaction tank and outputting purified tail water, and residual ozone micro-nano bubbles in the miscible water are removed through bubble collision reaction by oxygen bubbles formed based on aeration in the aeration removal tank.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of circulating aquaculture water treatment systems based on ozone micro-nano bubble.It is applicable to aquaculture technology and environmental engineering technology and other fields. BACKGROUND

[0002] Currently, intensive aquaculture technology promotes the spread of fish infectious diseases. In order to avoid the harm of pathogenic bacteria to fish health, aquaculture practitioners choose to add antibiotics, a low-cost and efficient method, to the feed to prevent diseases and promote fish growth, thereby increasing the harvest. Antibiotic abuse seriously endangers food safety, the ecological environment and human health, and its use should be reduced through scientific management and alternative solutions.

[0003] To solve the problem of antibiotics in aquaculture industry, the key lies in solving the problem of fish infectious diseases. Currently, recirculating aquaculture is one of the technical solutions to solve this problem. Recirculating aquaculture recycles wastewater generated in the culture pond through a series of water treatment units, solving the problem of wastewater discharge from aquaculture, and achieving infectious disease prevention and control with sterilization processes. The conventional recirculating water treatment process generally includes filtration, foam separation, microbial treatment, and sterilization and disinfection processes, among which sterilization and disinfection are usually ozone or ultraviolet disinfection.

[0004] Chinese patent with patent publication number CN117003433A achieves the reuse of aquaculture tail water through microfiltration, protein separation, ozone disinfection, aeration tank (biochemical tank), and ultraviolet disinfection. However, the ultraviolet disinfection process is affected by the service life of the ultraviolet lamp, and the sterilization efficiency will gradually decrease after a period of use; the ozone disinfection process is prone to produce disinfection by-products such as bromate, especially when applied in seawater aquaculture, as a large amount of bromide exists in seawater, which easily produces high concentrations of bromate, endangering the health of cultured animals.

[0005] In order to avoid the problem of disinfection by-products, Chinese patent with patent publication number CN108658209A uses filtration, foam separation + advanced oxidation to achieve the treatment of recirculating aquaculture water. The presence of hydroxyl radicals in the advanced oxidation process can indeed effectively prevent the production of bromate, but as hydroxyl radicals continuously react with organic matter in water, ozone remaining in the bubbles will continue to enter the water and react with bromide to produce bromate; Therefore, when applying ozone-based advanced oxidation technology, very precise concentration control is required, as excessive gas-liquid ratio will also produce bromate, and too low gas-liquid ratio will make it difficult to ensure the treatment effect. In addition, filtration, air flotation, aeration and biochemical processes in conventional recirculating water treatment processes require additional energy supply, which increases the cost of treating aquaculture water. UTILITY MODEL CONTENT

[0006] The utility model wants to solve the technical problem: in view of the above problems, provide a kind of based on ozone micro-nano bubble's circulating aquaculture water treatment system.

[0007] The utility model employs technical scheme: a kind of based on ozone micro-nano bubble's circulating aquaculture water treatment system, it is characterized in that, including:

[0008] Contact reaction pool, for being dissolved by the micro-nano bubble water distribution pipe of its bottom with micro-nano bubble water aquaculture tail water, form miscible water, the micro-nano bubble water contains ozone micro-nano bubble;

[0009] Static reaction pool, for receiving the miscible water of the contact reaction pool output, and miscible water is outputted outside after a certain time;

[0010] Aeration removal pool, for receiving the miscible water of the static reaction pool output, and outputting after purifying tail water, the oxygen bubble based on aeration in the aeration removal pool, residual ozone micro-nano bubble in miscible water is removed by bubble collision reaction.

[0011] Still include:

[0012] Artificial wetland module, setting in the contact reaction pool upstream, and aquaculture tail water enters the contact reaction pool after artificial wetland module.

[0013] The artificial wetland module, including being arranged in sequence along the direction of aquaculture tail water flow:

[0014] Down vertical flow artificial wetland;

[0015] Up vertical flow artificial wetland, and the down vertical flow artificial wetland are connected by bottom water overflow, and are connected by overflow weir with the contact reaction pool.

[0016] The down vertical flow artificial wetland front end is equipped with pre-sedimentation tank, and pre-sedimentation tank is connected aquaculture pond by first water pipe, and first water pipe is equipped with lifting pump;Pre-sedimentation tank is connected with down vertical flow artificial wetland main body by overflow weir.

[0017] The down vertical flow artificial wetland and up vertical flow artificial wetland have filler and are planted with emergent aquatic plants, and filler is sequentially drainage layer, transition layer, main body layer and water distribution layer from bottom to top;

[0018] The drainage layer selects gravel with particle size of 10-30mm, and filler thickness is 0.2-0.3m;The transition layer selects gravel with particle size of 5-10mm, and filler thickness is 0.2-0.3m;The main body layer selects zeolite with particle size of 2-6mm, and filler thickness is 0.4-1.4m;The water distribution layer selects gravel with particle size of 10-30mm, and filler thickness is 0.2-0.3m.

[0019] The aeration removal tank is connected with the ozone nanobubble generator through a second water conveying pipe, and the ozone nanobubble generator is connected with the micro-nanobubble water distributing pipe through a third water conveying pipe.

[0020] The ozone nanobubble generator is used for preparing oxygen into ozone, and the ozone is introduced into the purified tail water in the second water conveying pipe to form micro-nanobubble water.

[0021] The third water conveying pipe is provided with a pressure adjusting tank.

[0022] The pressure value adjusted by the pressure adjusting tank is calculated according to the following formula:

[0023] Pressure value (kPa) = [contact reaction tank water depth (m) + 1] * 9.8

[0024] The contact reaction tank is provided with a skimmer and a residue discharging pipe.

[0025] The aeration removal tank is provided with a water outlet well, and the purified tail water overflows into the water outlet well.

[0026] The aeration removal tank is provided with a gas supply pipe at the upper portion, and an aeration pipe at the bottom, the aeration pipe is connected with the gas supply pipe, and the ratio of the aeration amount to the water flow is 1:5-1:15.

[0027] The ratio of the hydraulic retention time of the contact reaction tank to the static reaction tank is 1:1-1:3, and the ratio of the hydraulic retention time of the contact reaction tank to the aeration removal tank is 1:0.5-1:2.

[0028] The beneficial effects of the utility model are as follows:

[0029] In the contact reaction tank, the aquaculture tail water and the micro-nanobubble water are fully mixed through the micro-nanobubble water distributing pipe at the bottom, the ozone is introduced into the aquaculture tail water to realize sterilization and disinfection, and the ozone micro-nanobubble is used for air flotation, due to the action of the bubbles, part of the small particles are brought to the water surface to form dregs, so that the dregs are separated from the water.

[0030] In the utility model, the static reaction tank receives the mixed water output by the contact reaction tank, and outputs the mixed water to the outside after a certain time, so that the ozone micro-nanobubble and the organic matter in the water have enough time for further reaction.

[0031] In the utility model, the oxygen bubbles formed based on aeration in the aeration removal tank remove the residual ozone micro-nanobubbles in the mixed water through bubble collision reaction, so that the high concentration of bromate is avoided.

[0032] The utility model discloses the senior oxidation process is divided into contact oxidation, standing reaction and aeration removal three stages, guarantees the organic matter degradation efficiency, and makes the oxidant concentration more easily control simultaneously, protects the breeding animal and is not affected by ozone and byproduct.

[0033] The utility model makes full use of the gas floatation in the senior oxidation process, and the pretreatment process is optimized, and only needs the artificial wetland auxiliary processing nitrogen phosphorus, and the low additional power demand.

[0034] Due to the existence of aeration removal process in the utility model, the dissolved oxygen content in the system effluent is extremely high, and according to the type of breeding animal, only a small amount of aeration is needed in the breeding pond or even no aeration is needed. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 It is the plane arrangement schematic drawing of example.

[0036] Figure 2 It is the I-I section schematic drawing of Figure 1 .

[0037] Figure 3 It is the II-II section schematic drawing of Figure 1 .

[0038] Figure 4 It is the chromatographic change of 6 kinds of antibiotics before and after the treatment of example.

[0039] REFERENCE SIGNS:

[0040] Breeding pond 1;

[0041] Downward vertical flow artificial wetland 2;

[0042] Pre-deposition tank 21;

[0043] Drainage layer 231;Transition layer 232;Main body layer 233;Water distribution layer 234;

[0044] Upward vertical flow artificial wetland 3;

[0045] Contact reaction tank 4;

[0046] Micro-nano bubble water distribution pipe 41;Skimmer 42;Slag discharge pipe 43;Water hole 44;

[0047] Standing reaction tank 5;

[0048] Aeration removal tank 6;

[0049] Gas supply pipe 61;Aeration pipe 62;Water well 63;

[0050] Ozone micro-nano bubble generator 7;

[0051] Pressure regulating tank 8;

[0052] First valve 91; second valve 92; third valve 93; fourth valve 94; fifth valve 95; sixth valve 96;

[0053] Lift pump 10. DETAILED DESCRIPTION

[0054] In order to better understand the technical solutions of the present application, the embodiments of the present application are described in detail below with reference to the drawings.

[0055] It should be clear that the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0056] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0057] As Figures 1 to 3 The present embodiment is an ozone micro-nano bubble-based circulating aquaculture water treatment system, which comprises an aquaculture pond, an artificial wetland module, a contact reaction pond, a static reaction pond, an aeration removal pond, etc. The artificial wetland module comprises a pre-sedimentation pond, a downward vertical flow artificial wetland, and an upward vertical flow artificial wetland. The aquaculture tail water of the aquaculture pond is sequentially treated by the pre-sedimentation pond, the downward vertical flow artificial wetland, the upward vertical flow artificial wetland, the contact reaction pond, the static reaction pond, and the aeration removal pond, and then returned to the aquaculture pond.

[0058] In the present embodiment, the aquaculture pond is connected to the water inlet of the pre-sedimentation pond through a first water inlet pipe. The first water inlet pipe is provided with a first valve and a lift pump. The aquaculture tail water in the aquaculture pond is pressurized by the lift pump and then introduced into the pre-sedimentation pond.

[0059] In the present embodiment, the pre-sedimentation pond is provided with a water inlet and a residue discharge port on the same side. The water inlet is connected to the upper part of the pre-sedimentation pond, and the residue discharge port is connected to the bottom of the pre-sedimentation pond. The bottom of the pre-sedimentation pond is gradually raised along the water inlet direction, and the slope ratio is 0.01-0.03. The pre-sedimentation pond is connected to the main body of the downward vertical flow artificial wetland through an overflow port.

[0060] In the present embodiment, the downward vertical flow artificial wetland is provided with fillers and planted with emergent aquatic plants. The fillers are sequentially arranged from bottom to top as a drainage layer, a transition layer, a main layer, and a water distribution layer.

[0061] The down-flow vertical-flow constructed wetland and the up-flow vertical-flow constructed wetland are connected through a bottom water overflow in the example, the up-flow vertical-flow constructed wetland has fillers and is planted with emergent aquatic plants, and the fillers are sequentially arranged from bottom to top as a drainage layer, a transition layer, a main layer and a water distribution layer.

[0062] In the embodiment, the drainage layer is selected from gravels with a particle size of 10-30 mm, and the thickness of the fillers is 0.2-0.3 m; the transition layer is selected from gravels with a particle size of 5-10 mm, and the thickness of the fillers is 0.2-0.3 m; the main layer is selected from zeolites with a particle size of 2-6 mm, and the thickness of the fillers is 0.4-1.4 m; and the water distribution layer is selected from gravels with a particle size of 10-30 mm, and the thickness of the fillers is 0.2-0.3 m.

[0063] In the example, the emergent aquatic plants can be planted with cattails, water celery and the like when treating freshwater aquaculture water, and can be planted with mangrove plants, reeds and the like when treating seawater aquaculture water.

[0064] In the embodiment, the up-flow vertical-flow constructed wetland is connected with the contact reaction tank through an overflow, and the bottom of the contact reaction tank is provided with a micro-nano bubble water distribution pipe for fully mixing the aquaculture tail water with micro-nano bubble water (containing ozone micro-nano bubbles) to form mixed water. The micro-nano bubble water distribution pipe 41 is made of PVC or stainless steel pipe, and is uniformly and densely provided with water distribution holes with a diameter of 5 mm.

[0065] In the embodiment, the upstream end of the contact reaction tank is provided with a water supplement pipe, and the downstream end of the contact reaction tank is provided with a skimmer and a residue discharge pipe.

[0066] In the example, the contact reaction tank is connected with the standing reaction tank through a water overflow, the standing reaction tank is connected with the aeration removal tank through a water outlet channel, and the water outlet channel and the water overflow are spaced apart from each other. The mixed water output from the contact reaction tank enters the standing reaction tank through the water overflow, flows from the water overflow to the water outlet channel in the standing reaction tank, and is output from the water outlet channel to the aeration removal tank after a certain period of time.

[0067] In the embodiment, the aeration removal tank is provided with a gas supply pipe at the upper portion and an aeration pipe at the bottom, the aeration pipe is connected with the gas supply pipe, the gas is oxygen (or air), and the ratio of the aeration amount to the water flow is 1:5-1:15. The downstream end of the aeration removal tank is provided with a water outlet well, and the purified tail water is overflowed into the water outlet well.

[0068] In the embodiment, the water outlet well is connected with an ozone micro-nano bubble generator through a second water pipe, the ozone micro-nano bubble generator is connected with the micro-nano bubble water distribution pipe at the bottom of the contact reaction tank through a third water pipe, the fifth valve is arranged on the second water pipe, the sixth valve and a pressure regulating tank are arranged on the third water pipe.

[0069] The ozone micro-nano bubble generator in this example prepares oxygen into ozone and passes into the purified tail water in the second water delivery pipe to make micro-nano bubble water. The micro-nano bubble water is adjusted in pressure by the pressure adjusting tank and then passes into the micro-nano bubble water distribution pipe of the contact reaction tank.

[0070] In this example, the ozone micro-nano bubble generator is designed in an integrated manner and internally integrated with an ozone generator, a micro-nano bubble generator, a water pump, a flow meter, a pressure gauge, an intelligent controller, etc. The flow of the nano bubble water is 1-30 L / min, the ozone concentration is 120-140 mg / L, the gas flow is 50-3000 mL / min, and the power is 500-5000 W.

[0071] In this example, the pressure value adjusted by the pressure adjusting tank is calculated according to the following formula:

[0072] Pressure value (kPa) = [water depth of the contact reaction tank (m) + 1] x 9.8

[0073] In this example, the water outlet well is connected to the breeding tank through the fourth water delivery pipe and the fifth pipe for sending the purified tail water treated by the constructed wetland module, the contact reaction tank, the standing reaction tank, and the aeration removal tank back to the breeding tank. The fourth water delivery pipe is provided with a second valve, and the fifth pipe is provided with a third valve. The water outlet well is connected to the external discharge pipe through the fourth water delivery pipe, and the external discharge pipe is provided with a fourth valve.

[0074] In this example, the hydraulic retention time ratio of the contact reaction tank to the standing reaction tank is 1:1-1:3, and the hydraulic retention time ratio of the contact reaction tank to the aeration removal tank is 1:0.5-1:2.

[0075] In this example, the process of treating the circulating aquaculture water by the circulating aquaculture water treatment system is as follows:

[0076] 1) The breeding tail water in the breeding tank is pressurized by the booster pump and then delivered to the pre-sedimentation tank;

[0077] 2) In the pre-sedimentation tank, the solid particles of the breeding tail water are precipitated to the bottom of the pre-sedimentation tank by the sedimentation action and are periodically removed through the slag discharge port at the bottom. The pre-sedimented tail water enters the water distribution layer of the downward vertical flow constructed wetland through overflow and then passes through the main layer, the transition layer, and the drainage layer in turn. In the drainage layer, the water passes through the water inlet and enters the drainage layer of the upward vertical flow constructed wetland;

[0078] 3) In the upward vertical flow constructed wetland, the breeding tail water passes through the drainage layer, the transition layer, the main layer, and the water distribution layer in turn and then overflows into the contact reaction tank;

[0079] 4) In the contact reaction tank, the breeding tail water and the micro-nano bubble water are fully mixed by the micro-nano bubble water distribution pipe at the bottom to form mixed water; due to the action of the bubbles, part of the small particles are taken to the water surface to form scum, which is finally swept into the residue discharge pipe by the skimmer to be separated from the water;

[0080] 5) The effluent of the contact reaction tank enters the static reaction tank through the water passage, and the mixed water stays in the static reaction tank for a certain period of time to ensure further reaction of the micro-nano bubbles and the organic matter in the water, and then the tail water enters the aeration removal tank;

[0081] 6) In the aeration removal tank, oxygen is supplied to the bottom of the tank through the gas supply pipe and the aeration pipe, and the residual micro-nano bubbles are removed through bubble collision reaction, and the purified tail water enters the effluent well through overflow;

[0082] 7) The purified tail water is supplied to the ozone micro-nano bubble generator through the regulating valve at a ratio of 1 / 20 to 1 / 10; the ozone micro-nano bubble generator prepares oxygen into ozone and makes it into micro-nano bubble water in the purified tail water; after pressure regulation by the pressure regulating tank, the micro-nano bubble water is supplied to the micro-nano bubble water distribution pipe of the contact reaction tank;

[0083] 8) The remaining purified tail water is re-supplied to the breeding tank through the valve for recycling.

[0084] The ozone micro-nano bubble-based circulating breeding water treatment system in this embodiment also has the function of sterilizing the make-up water, and the specific process is as follows: the natural water filtered by sand is transported to the front end of the contact reaction tank through the make-up water pipe, and then the make-up water is supplied to the breeding tank after the above steps 4) to 8).

[0085] The ozone micro-nano bubble-based circulating breeding water treatment system in this embodiment also has the function of treating the breeding tail water to meet the discharge standard, and the specific process is as follows: the breeding tail water in the breeding tank is discharged to the nearby water area through the discharge pipeline after the above steps 1) to 7).

[0086] The ozone micro-nano bubble-based circulating breeding water treatment system in this embodiment also has the function of backwashing the vertical flow constructed wetland, and the specific process is as follows: the pipeline from the breeding tank to the downward vertical flow constructed wetland is closed by the valve, water is introduced from the make-up water pipeline to the outlet of the upward vertical flow constructed wetland, the residue discharge port of the pre-sedimentation tank of the downward vertical flow constructed wetland is opened, and the backwashing water is discharged through the residue discharge port of the pre-sedimentation tank after passing through the upward vertical flow constructed wetland and the downward vertical flow constructed wetland in reverse.

[0087] The following is illustrated by a specific example:

[0088] A ozone micro-nano bubble-based circulating breeding water treatment system as shown in Figure 1 is built in a certain grouper breeding farm, and the treatment scale is 1m 3 / h, the cultured animals are stonefish, and the system is operated according to the above steps 1) to 8), after stable operation for 3 days, the water samples in the inlet and outlet of the culture pond are detected, and the water quality change is shown in Table 1. After the treatment of the circulating culture water, the water quality indexes such as ammonia nitrogen and nitrite nitrogen in the inlet water of the culture pond reach the fishery water quality standard, and the dissolved oxygen component in the water is improved after the treatment, which is beneficial to the culture process of stonefish and other marine products.

[0089] Table 1 Water quality change before and after treatment of culture water

[0090]

[0091] Through the water supplement pipeline, antibiotics and stimulating cryptosporidium are added to simulate the antibiotic degradation ability and the disease and pest control ability of the system. The added antibiotics are oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC), sulfadiazine (SDZ), sulfamethazine (SMZ) and sulfamethoxazole (SMX), and the concentration of the six antibiotics after mixing with the culture seawater reaches 100 μg / L. The number of stimulating cryptosporidium larvae added is 1.4 x 10 2 cells / mL.

[0092] According to the above process of sterilizing the supplemented seawater, the antibiotic concentrations before and after treatment are detected by liquid chromatography-mass spectrometry, and the live and dead of stimulating cryptosporidium are determined by fluorescence staining. After the treatment, all the six antibiotics are completely degraded (as shown in Figure 4 , and all the stimulating cryptosporidium are completely killed, which shows that the system has the degradation ability of pollutants such as antibiotics and the disease and pest control ability.

Claims

1. An ozone micro-nano bubble-based circulating aquaculture water treatment system, characterized in that, The application relates to a water purification system for aquaculture tail water, which comprises the following parts: a contact reaction tank for fully mixing the aquaculture tail water with micro-nano bubble water containing ozone micro-nano bubbles through a micro-nano bubble water distribution pipe at the bottom of the contact reaction tank to form mixed water; a static reaction tank for receiving the mixed water output by the contact reaction tank and outputting the mixed water after a certain time; an aeration removal tank for receiving the mixed water output by the static reaction tank and outputting purified tail water, wherein the residual ozone micro-nano bubbles in the mixed water are removed through bubble collision reaction based on the oxygen bubbles formed by aeration in the aeration removal tank.

2. The ozone micro-nano bubble-based recirculating aquaculture system of claim 1, wherein, The application further comprises: an artificial wetland module arranged upstream of the contact reaction tank, wherein the aquaculture tail water enters the contact reaction tank after passing through the artificial wetland module.

3. The ozone micro-nano bubble-based recirculating aquaculture system of claim 2, wherein, The artificial wetland module comprises the following parts arranged in sequence along the flow direction of the aquaculture tail water: a downward vertical flow artificial wetland; an upward vertical flow artificial wetland connected with the downward vertical flow artificial wetland through a bottom water inlet and connected with the contact reaction tank through an overflow inlet.

4. The ozone micro-nano bubble-based recirculating aquaculture system of claim 3, wherein, A pre-sedimentation tank is arranged at the front end of the downward vertical flow artificial wetland, the pre-sedimentation tank is connected with an aquaculture pond through a first water inlet pipe, a lifting pump is arranged on the first water inlet pipe, and the pre-sedimentation tank is connected with the main body of the downward vertical flow artificial wetland through an overflow inlet.

5. The ozone micro-nano bubble-based recirculating aquaculture system according to claim 3, wherein The downward vertical flow artificial wetland and the upward vertical flow artificial wetland are filled with fillers and planted with emergent aquatic plants, and the fillers are arranged in sequence from bottom to top as a drainage layer, a transition layer, a main body layer and a water distribution layer; the drainage layer is made of gravel with a particle size of 10-30 mm, and the filler thickness is 0.2-0.3 m; the transition layer is made of gravel with a particle size of 5-10 mm, and the filler thickness is 0.2-0.3 m; the main body layer is made of zeolite with a particle size of 2-6 mm, and the filler thickness is 0.4-1.4 m; and the water distribution layer is made of gravel with a particle size of 10-30 mm, and the filler thickness is 0.2-0.3 m.

6. The ozone micro-nano bubble-based recirculating aquaculture system according to claim 1, wherein: The aeration removal tank is connected with an ozone nano bubble generator through a second water inlet pipe, and the ozone nano bubble generator is connected with the micro-nano bubble water distribution pipe through a third water inlet pipe; the ozone nano bubble generator is used for preparing oxygen into ozone, and the ozone is made into micro-nano bubble water by being introduced into the purified tail water input into the second water inlet pipe.

7. The ozone micro-nano bubble-based recirculating aquaculture system of claim 6, wherein: A pressure regulating tank is arranged on the third water inlet pipe.

8. The ozone micro-nano bubble-based recirculating aquaculture system of claim 7, wherein: The pressure value regulated by the pressure regulating tank is calculated according to the following formula: pressure value (kPa) = [contact reaction tank water depth (m) + 1] * 9.

8.

9. The ozone micro-nano bubble-based recirculating aquaculture system according to claim 1, wherein: The contact reaction tank is provided with a skimmer and a residue discharge pipe.

10. The ozone micro-nano bubble-based recirculating aquaculture system according to claim 1, wherein: A water outlet well is arranged at the rear end of the aeration removal tank, and the purified tail water overflows into the water outlet well.

11. The ozone micro-nano bubble-based recirculating aquaculture system according to claim 1, wherein: Air supply pipes are arranged on the upper part of the aeration removal tank, and air pipes are arranged at the bottom of the aeration removal tank and connected with the air supply pipes, and the ratio of the aeration amount to the water flow is 1:5-1:

15.

12. The ozone micro-nano bubble-based recirculating aquaculture system according to claim 1, wherein: The hydraulic retention time ratio of the contact reaction tank to the static reaction tank is 1:1-1:3, and the hydraulic retention time ratio of the contact reaction tank to the aeration removal tank is 1:0.5-1:2.

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