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

Abstract

The invention 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 invention 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 present invention relates to a circulating aquaculture water treatment system based on ozone micro-nano bubbles, which is applicable to the fields of aquaculture technology and environmental engineering technology. Background Art

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

[0003] The key to solving the antibiotic problem in the aquaculture industry is to solve the problem of fish infectious diseases. At present, recirculating aquaculture is one of the technical solutions to this problem. Recirculating aquaculture uses a series of water treatment units to treat the wastewater generated in the aquaculture pond and recycle it for reuse. While solving the problem of aquaculture water discharge, it also uses sterilization technology to achieve infectious disease prevention and control. Conventional circulating water treatment processes generally include: filtration, foam separation, microbial treatment, and sterilization and disinfection processes, among which sterilization and disinfection are usually ozone or ultraviolet disinfection.

[0004] The Chinese patent with the patent publication number CN117003433A realizes the reuse of aquaculture tail water through microfiltration, protein separation, ozone disinfection, aeration and oxygenation pool (biochemical pool) and ultraviolet disinfection. However, the ultraviolet disinfection process is affected by the life of the ultraviolet lamp, and the sterilization efficiency usually decreases gradually after a period of use; the ozone disinfection process is prone to produce disinfection by-products such as bromate, especially when applied to the marine aquaculture process, due to the large amount of bromide ions in seawater, it is very easy to produce high concentrations of bromate, which endangers the health of farmed animals.

[0005] In order to avoid the problem of disinfection by-products, the Chinese patent with patent publication number CN108658209A adopts filtration, foam separation + advanced oxidation to achieve the treatment of circulating aquaculture water. The presence of hydroxyl radicals in the advanced oxidation process can indeed effectively prevent the generation of bromate, but as hydroxyl radicals continue to react with organic matter in the water, ozone remaining in the bubbles will continue to enter the water and react with bromide ions to generate bromate; therefore, when applying ozone-based advanced oxidation technology, very precise concentration control is required. Too high a gas-liquid ratio will also produce bromate, while too low a gas-liquid ratio will make it difficult to ensure the treatment effect. In addition, filtration, flotation, aeration and biochemistry in conventional circulating water treatment processes require additional energy supply, which adds to the cost of treating aquaculture water. Summary of the invention

[0006] The technical problem to be solved by the present invention is: in view of the above-mentioned problems, a circulating aquaculture water treatment system based on ozone micro-nano bubbles is provided.

[0007] The technical solution adopted by the present invention is: a circulating aquaculture water treatment system based on ozone micro-nano bubbles, characterized in that it includes:

[0008] The contact reaction tank is used to fully mix the aquaculture tail water with the micro-nano bubble water through the micro-nano bubble water distribution pipe at the bottom thereof to form miscible water, wherein the micro-nano bubble water contains ozone micro-nano bubbles;

[0009] A static reaction tank, used to receive the miscible water outputted from the contact reaction tank and output the miscible water after a certain period of time;

[0010] The aeration removal tank is used to receive the miscible water output from the static reaction tank and output purified tail water. The oxygen bubbles formed by aeration in the aeration removal tank remove the residual ozone micro-nano bubbles in the miscible water through bubble collision reaction.

[0011] Also includes:

[0012] The artificial wetland module is arranged upstream of the contact reaction pool, and the aquaculture tail water enters the contact reaction pool after passing through the artificial wetland module.

[0013] The artificial wetland module includes:

[0014] Downward vertical flow constructed wetland;

[0015] The upward vertical flow artificial wetland is connected to the downward vertical flow artificial wetland through a bottom water outlet, and is connected to the contact reaction pool through an overflow outlet.

[0016] A pre-sedimentation tank is provided at the front end of the downward vertical flow artificial wetland, and the pre-sedimentation tank is connected to the breeding pool through a first water pipe, and a lifting pump is installed on the first water pipe; the pre-sedimentation tank is connected to the main body of the downward vertical flow artificial wetland through an overflow port.

[0017] The downward vertical flow artificial wetland and the upward vertical flow artificial wetland have fillers and are planted with emergent aquatic plants, and the fillers are a drainage layer, a transition layer, a main layer and a water distribution layer from bottom to top;

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

[0019] The aeration removal tank is connected to the ozone nano bubble generator via the second water pipe, and the ozone nano bubble generator is connected to the micro-nano bubble water distribution pipe via the third water pipe;

[0020] The ozone nano bubble generator is used to prepare ozone from oxygen, and the ozone is passed into the purified tail water input by the second water delivery pipe to prepare micro-nano bubble water.

[0021] The third water delivery pipe is equipped with a pressure regulating tank.

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

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

[0025] The contact reaction tank is equipped with a slag skimmer and a slag discharge pipe.

[0026] A water outlet well is arranged at the rear end of the aeration and removal tank, and the tail water overflows into the water outlet well after purification.

[0027] An air supply pipe is arranged on the upper part of the aeration removal tank, and an aeration pipe is arranged at the bottom of the tank. The aeration pipe is connected with the air supply pipe, and the ratio of aeration volume to water flow is 1:5 to 1:15.

[0028] The hydraulic retention time ratio of the contact reaction tank to the static reaction tank is 1:1 to 1:3; the hydraulic retention time ratio of the contact reaction tank to the aeration removal tank is 1:0.5 to 1:2.

[0029] The beneficial effects of the present invention are:

[0030] The present invention fully mixes aquaculture tail water with micro-nano bubble water through a micro-nano bubble water distribution pipe at the bottom in a contact reaction tank, introduces ozone into the aquaculture tail water to achieve sterilization and disinfection, and simultaneously utilizes ozone micro-nano bubbles to achieve flotation. Due to the action of the bubbles, some tiny particles are brought to the water surface to form scum, thereby being separated from the water.

[0031] In the present invention, the static reaction tank receives the miscible water outputted from the contact reaction tank, and outputs the miscible water after a certain period of time, so as to ensure that the ozone micro-nano bubbles have enough time to further react with the organic matter in the water.

[0032] In the present invention, oxygen bubbles formed by aeration in the aeration removal tank remove residual ozone micro-nano bubbles in the miscible water through bubble collision reaction, so as to avoid the generation of high concentration of bromate.

[0033] The present invention divides the advanced oxidation process into three stages: contact oxidation, static reaction and aeration removal. While ensuring the degradation efficiency of organic matter, the concentration of the oxidant is easier to control, protecting the farmed animals from the influence of ozone and its by-products.

[0034] The present invention makes full use of the flotation effect in the advanced oxidation process, optimizes the pre-treatment process, and only requires artificial wetlands to assist in the treatment of nitrogen and phosphorus, with low demand for additional power.

[0035] Due to the existence of the aeration removal process in the present invention, the dissolved oxygen content in the system outlet water is extremely high, and only a small amount of aeration or even no aeration is required in the breeding pond according to the type of breeding animals. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the plan layout of the embodiment.

[0037] Figure 2 for Figure 1 Schematic diagram of section II.

[0038] Figure 3 for Figure 1 Schematic diagram of the II-II cross section.

[0039] Figure 4 The chromatographic changes before and after treatment of 6 antibiotics in this example.

[0040] Reference numerals:

[0041] Breeding pond 1;

[0042] Downward vertical flow constructed wetland 2;

[0043] Pre-sedimentation tank 21;

[0044] Drainage layer 231; transition layer 232; main layer 233; water distribution layer 234;

[0045] Upward vertical flow constructed wetland 3;

[0046] Contact reaction tank 4;

[0047] Micro-nano bubble water distribution pipe 41; slag skimmer 42; slag discharge pipe 43; water hole 44;

[0048] The reaction tank is left to stand 5;

[0049] Aeration removal tank 6;

[0050] Air supply pipe 61; aeration pipe 62; water outlet well 63;

[0051] Ozone micro-nano bubble generator 7;

[0052] Pressure regulating tank 8;

[0053] A first valve 91; a second valve 92; a third valve 93; a fourth valve 94; a fifth valve 95; and a sixth valve 96;

[0054] Lift pump 10. DETAILED DESCRIPTION

[0055] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0056] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0057] 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 plural forms, unless the context clearly indicates other meanings.

[0058] like Figures 1 to 3 As shown, this embodiment is a circulating aquaculture water treatment system based on ozone micro-nano bubbles, including a breeding pond, an artificial wetland module, a contact reaction tank, a static reaction tank, an aeration removal tank, etc., wherein the artificial wetland module includes a pre-sedimentation tank, a downward vertical flow artificial wetland and an upward vertical flow artificial wetland. The aquaculture tail water of the breeding pond is sequentially treated by the pre-sedimentation tank, the downward vertical flow artificial wetland, the upward vertical flow artificial wetland, the contact reaction tank, the static reaction tank and the aeration removal tank and then returned to the breeding pond.

[0059] In this example, the aquaculture pond is connected to the water inlet of the pre-sedimentation tank via the first water pipe, on which the first valve and the lifting pump are installed, and the aquaculture tail water in the aquaculture pond is pressurized by the lifting pump and then connected to the pre-sedimentation tank.

[0060] In this embodiment, a water inlet and a slag outlet are provided on the same side of the pre-sedimentation tank, the upper part is connected to the water inlet, and the bottom of the tank is connected to the slag outlet. The bottom of the tank gradually rises along the water inlet direction, and the slope ratio is 0.01-0.03; the pre-sedimentation tank is connected to the main body of the downward vertical flow artificial wetland through an overflow port.

[0061] In this embodiment, the downward vertical flow artificial wetland has fillers and is planted with emergent aquatic plants. The fillers are, from bottom to top, a drainage layer, a transition layer, a main layer and a water distribution layer.

[0062] In this example, the downward vertical flow artificial wetland is connected to the upward vertical flow artificial wetland through the bottom water outlet. The upward vertical flow artificial wetland has fillers and is planted with emergent aquatic plants. The fillers are drainage layer, transition layer, main layer and water distribution layer from bottom to top.

[0063] In this embodiment, the drainage layer selects gravel with a particle size of 10 to 30 mm and a filler thickness of 0.2 to 0.3 m; the transition layer selects gravel with a particle size of 5 to 10 mm and a filler thickness of 0.2 to 0.3 m; the main layer selects zeolite with a particle size of 2 to 6 mm and a filler thickness of 0.4 to 1.4 m; the water distribution layer selects gravel with a particle size of 10 to 30 mm and a filler thickness of 0.2 to 0.3 m.

[0064] In this example, when treating freshwater aquaculture water, emergent aquatic plants such as cattails and water celery can be planted, and mangroves, reeds, etc. can be planted in seawater aquaculture water.

[0065] In this embodiment, the upward vertical flow artificial wetland is connected to the contact reaction pool through an overflow port, and a micro-nano bubble water distribution pipe is provided at the bottom of the contact reaction pool to fully mix the aquaculture tail water with the micro-nano bubble water (containing ozone micro-nano bubbles) to form miscible water. The micro-nano bubble water distribution pipe 41 is made of PVC or stainless steel pipe, and the pipe is evenly and densely covered with water distribution holes with a diameter of 5 mm.

[0066] In this embodiment, a water supply pipe is provided at the upstream end of the contact reaction tank, and a slag skimmer and a slag discharge pipe are provided at the downstream end of the contact reaction tank.

[0067] In this example, the contact reaction tank is connected to the static reaction tank through a water hole, and the static reaction tank is connected to the aeration removal tank through a water outlet channel. There is a certain distance between the water outlet channel and the water hole. The miscible water output from the contact reaction tank enters the static reaction tank through the water hole, flows from the water hole to the water outlet channel in the static reaction tank, and is output from the water outlet channel to the aeration removal tank after a certain period of time.

[0068] In this embodiment, an air supply pipe is arranged on the upper part of the aeration removal tank, and an aeration pipe is arranged at the bottom of the tank, the aeration pipe is connected to the air supply pipe, the gas passed is oxygen (or air), and the ratio of aeration volume to water flow is 1:5 to 1:15. A water outlet well is arranged at the downstream end of the aeration removal tank, and the purified tail water enters the water outlet well through overflow.

[0069] In this embodiment, the water outlet well is connected to the ozone micro-nano bubble generator via the second water pipe, and the ozone micro-nano bubble generator is connected to the micro-nano bubble water distribution pipe at the bottom of the contact reaction tank via the third water pipe, wherein the second water pipe is equipped with a fifth valve, and the third water pipe is equipped with a sixth valve and a pressure regulating tank.

[0070] In this example, the ozone micro-nano bubble generator prepares ozone from oxygen, and introduces the purified tail water input through the second water pipe to make micro-nano bubble water. The micro-nano bubble water is pressure-regulated by the pressure regulating tank and then introduced into the micro-nano bubble water distribution pipe of the contact reaction tank.

[0071] In this example, the ozone micro-nano bubble generator adopts an integrated design, which integrates an ozone generator, a micro-nano bubble generator, a water pump, a flow meter, a pressure gauge, an intelligent controller, etc.; the nano bubble water flow rate is 1-30L / min, the ozone concentration is 120-140mg / L, the gas flow rate is 50-3000mL / min, and the power is 500-5000W.

[0072] The pressure value adjusted by the pressure regulating tank in this embodiment is calculated according to the following formula:

[0073] Pressure value (kPa) = [water depth of contact reaction pool (m) + 1] × 9.8

[0074] In this embodiment, the outlet well is connected to the breeding pond via the fourth water pipe and the fifth pipeline, and is used to return the purified tail water after being treated by the artificial wetland module, the contact reaction tank, the static reaction tank, and the aeration removal tank to the breeding pond. The fourth water pipe is provided with a second valve, and the fifth pipeline is provided with a third valve. The outlet well is connected to the external discharge pipeline via the fourth water pipe, and the external discharge pipeline is provided with a fourth valve.

[0075] In this embodiment, the hydraulic retention time ratio of the contact reaction tank to the static reaction tank is 1:1 to 1:3; the hydraulic retention time ratio of the contact reaction tank to the aeration removal tank is 1:0.5 to 1:2.

[0076] The process of treating circulating aquaculture water by the circulating aquaculture water treatment system in this embodiment is as follows:

[0077] 1) The tail water in the aquaculture pond is pressurized by a lifting pump and then transported to the pre-sedimentation tank;

[0078] 2) In the pre-sedimentation tank, the solid particles of the aquaculture tail water are precipitated to the bottom of the pre-sedimentation tank through sedimentation, and are regularly removed through the slag discharge port at the bottom; the pre-sedimented tail water enters the water distribution layer of the downward vertical flow artificial wetland through overflow, and then passes through the main layer, transition layer and drainage layer in sequence; in the drainage layer, it enters the drainage layer of the upward vertical flow artificial wetland through the water outlet;

[0079] 3) In the upward vertical flow artificial wetland, the aquaculture tail water passes through the drainage layer, transition layer, main layer and water distribution layer in sequence and then overflows into the contact reaction tank;

[0080] 4) In the contact reaction tank, the aquaculture tail water and the micro-nano bubble water are fully mixed through the micro-nano bubble water distribution pipe at the bottom to form miscible water; due to the action of the bubbles, some tiny particles are brought to the water surface to form scum, which is finally swept into the slag discharge pipe by the skimmer to be separated from the water;

[0081] 5) The effluent from the contact reaction tank enters the static reaction tank through the water hole. The miscible water stays in the static reaction tank for a certain period of time to ensure further reaction between the micro-nano bubbles and the organic matter in the water. After that, the tail water enters the aeration removal tank;

[0082] 6) In the aeration removal tank, oxygen is introduced into the bottom of the tank through the air supply pipe and the aeration pipe, and the residual micro-nano bubbles are removed through the bubble collision reaction. The purified tail water enters the outlet well through the overflow;

[0083] 7) 1 / 20 to 1 / 10 of the purified tail water is introduced into the ozone micro-nano bubble generator by adjusting the valve; the ozone micro-nano bubble generator prepares ozone from oxygen and introduces the purified tail water into micro-nano bubble water; after the pressure is adjusted by the pressure regulating tank, the micro-nano bubble water is introduced into the water distribution pipe of the contact reaction tank;

[0084] 8) The remaining purified tail water re-enters the aquaculture pond through a valve for recycling.

[0085] The circulating aquaculture water treatment system based on ozone micro-nano bubbles in this embodiment also has the function of sterilizing the supplementary water. The specific process is: the natural water after sand filtration is transported to the front end of the contact reaction tank through the water supply pipe, and then replenished into the aquaculture pond after the above steps 4) to 8).

[0086] The circulating aquaculture water treatment system based on ozone micro-nano bubbles in this embodiment also has the function of discharging the aquaculture tail water after treating it to meet the standards. The specific process is: the aquaculture tail water of the aquaculture pond is discharged to the nearby waters through the external discharge pipeline after the above steps 1) to 7).

[0087] In this example, the circulating aquaculture water treatment system based on ozone micro-nano bubbles also has the function of backwashing the vertical flow artificial wetland. The specific process is: close the pipeline from the aquaculture pond to the downstream vertical flow artificial wetland through a valve, lead water from the supplementary water pipeline to the outlet of the upstream vertical flow artificial wetland, open the slag discharge port of the pre-sedimentation tank of the downstream vertical flow artificial wetland, and the backwash water passes through the upstream vertical flow artificial wetland and the downstream vertical flow artificial wetland in the opposite direction and is discharged through the slag discharge port of the pre-sedimentation tank.

[0088] The following is a specific example:

[0089] In a grouper farm, Figure 1 The circulating aquaculture water treatment system based on ozone micro-nano bubbles has a treatment scale of 1m 3 / h, the cultured animal is blue grouper, and the above steps 1) to 8) are operated. After stable operation for 3 days, the influent and effluent of the culture pond are sampled and tested, and the water quality changes are shown in Table 1. After the circulating culture water treatment, the water quality indicators of the culture pond influent, such as ammonia nitrogen and nitrite nitrogen, all meet the fishery water quality standards, and the dissolved oxygen content of the water is improved after treatment, which is beneficial to the culture process of seafood such as grouper.

[0090] Table 1 Changes in water quality before and after aquaculture water treatment

[0091]

[0092]

[0093] Antibiotics and Cryptocaryon irritans were added through the water supply pipeline to simulate the degradation capacity of antibiotics in the system and its ability to prevent and control diseases and insect pests. The antibiotics added were oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC), sulfadiazine (SDZ), sulfamethoxazole (SMZ) and sulfamethoxazole (SMX). The concentrations of the six antibiotics after mixing with the aquaculture seawater reached 100 μg / L. The number of larvae of Cryptocaryon irritans added was 1.4×10 2 cells / mL.

[0094] The above-mentioned process of sterilizing supplementary seawater was followed, and the antibiotic concentrations before and after treatment were detected by liquid chromatography-mass spectrometry, and the live or dead Cryptocaryon irritans were determined by fluorescent staining. After treatment, all six antibiotics were degraded (e.g. Figure 4 As shown in the figure, all Cryptocaryon irritans were completely killed, indicating that the system has the ability to degrade pollutants such as antibiotics and prevent and control diseases and insect pests.

Claims

1. A circulating aquaculture water treatment system based on ozone micro-nano bubbles, characterized in that: include: The contact reaction tank is used to fully mix the aquaculture tail water with the micro-nano bubble water through the micro-nano bubble water distribution pipe at the bottom thereof to form miscible water, wherein the micro-nano bubble water contains ozone micro-nano bubbles; A static reaction tank, used to receive the miscible water outputted from the contact reaction tank and output the miscible water after a certain period of time; The aeration removal tank is used to receive the miscible water output from the static reaction tank and output purified tail water. The oxygen bubbles formed by aeration in the aeration removal tank remove the residual ozone micro-nano bubbles in the miscible water through bubble collision reaction.

2. The circulating aquaculture water treatment system based on ozone micro-nano bubbles according to claim 1 is characterized in that: Also includes: The artificial wetland module is arranged upstream of the contact reaction pool, and the aquaculture tail water enters the contact reaction pool after passing through the artificial wetland module.

3. The circulating aquaculture water treatment system based on ozone micro-nano bubbles according to claim 2 is characterized in that: The artificial wetland module includes: Downward vertical flow constructed wetland; The upward vertical flow artificial wetland is connected to the downward vertical flow artificial wetland through a bottom water outlet, and is connected to the contact reaction pool through an overflow outlet.

4. The circulating aquaculture water treatment system based on ozone micro-nano bubbles according to claim 3 is characterized in that: A pre-sedimentation tank is provided at the front end of the downward vertical flow artificial wetland, and the pre-sedimentation tank is connected to the breeding pool through a first water pipe, and a lifting pump is installed on the first water pipe; the pre-sedimentation tank is connected to the main body of the downward vertical flow artificial wetland through an overflow port.

5. The circulating aquaculture water treatment system based on ozone micro-nano bubbles according to claim 3 is characterized in that: The downward vertical flow artificial wetland and the upward vertical flow artificial wetland have fillers and are planted with emergent aquatic plants, and the fillers are a drainage layer, a transition layer, a main layer and a water distribution layer from bottom to top; The drainage layer is made of gravel with a particle size of 10 to 30 mm and a filler thickness of 0.2 to 0.3 m; the transition layer is made of gravel with a particle size of 5 to 10 mm and a filler thickness of 0.2 to 0.3 m; the main layer is made of zeolite with a particle size of 2 to 6 mm and a filler thickness of 0.4 to 1.4 m; the water distribution layer is made of gravel with a particle size of 10 to 30 mm and a filler thickness of 0.2 to 0.3 m.

6. The circulating aquaculture water treatment system based on ozone micro-nano bubbles according to claim 1 is characterized in that: The aeration removal tank is connected to the ozone nano bubble generator via the second water pipe, and the ozone nano bubble generator is connected to the micro-nano bubble water distribution pipe via the third water pipe; The ozone nano bubble generator is used to prepare ozone from oxygen, and the ozone is passed into the purified tail water input by the second water delivery pipe to prepare micro-nano bubble water.

7. The circulating aquaculture water treatment system based on ozone micro-nano bubbles according to claim 6 is characterized in that: The third water delivery pipe is equipped with a pressure regulating tank.

8. The circulating aquaculture water treatment system based on ozone micro-nano bubbles according to claim 7 is characterized in that: The pressure value adjusted by the pressure regulating tank is calculated according to the following formula: Pressure value (kPa) = [water depth of contact reaction tank (m) + 1] × 9.

8.

9. The circulating aquaculture water treatment system based on ozone micro-nano bubbles according to claim 1 is characterized in that: The contact reaction tank is equipped with a slag skimmer and a slag discharge pipe.

10. The circulating aquaculture water treatment system based on ozone micro-nano bubbles according to claim 1 is characterized in that: A water outlet well is arranged at the rear end of the aeration and removal tank, and the tail water overflows into the water outlet well after purification.

11. The circulating aquaculture water treatment system based on ozone micro-nano bubbles according to claim 1 is characterized in that: An air supply pipe is arranged on the upper part of the aeration removal tank, and an aeration pipe is arranged at the bottom of the tank. The aeration pipe is connected with the air supply pipe, and the ratio of aeration volume to water flow is 1:5 to 1:

15.

12. The circulating aquaculture water treatment system based on ozone micro-nano bubbles according to claim 1 is characterized in that: The hydraulic retention time ratio of the contact reaction tank to the static reaction tank is 1:1 to 1:3; the hydraulic retention time ratio of the contact reaction tank to the aeration removal tank is 1:0.5 to 1:2.

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