Cultivation tail water circulation treatment system integrating fermentation and nitrogen and phosphorus removal

Abstract

The invention relates to the technical field of aquaculture, and discloses a culture tail water circulation treatment system integrating fermentation and nitrogen and phosphorus removal, comprising: a culture pond communicated with a water inlet of a microfilter, water in the culture pond being filtered by the microfilter and then being conveyed into a biochemical pond, the biochemical pond being communicated with the culture pond; the treatment assembly comprises a fermentation part and a nitrogen and phosphorus removal part, the fermentation part is communicated with a sewage draining exit of the microfilter, the fermentation part is used for carrying out fermentation treatment on wastewater generated by backwashing of the microfilter, fermentation liquor obtained after fermentation and water in the biochemical pool are both conveyed into the nitrogen and phosphorus removal part for nitrogen and phosphorus removal treatment, and the nitrogen and phosphorus removal part is communicated with the sewage draining exit of the microfilter. The supernate in the dephosphorization part is conveyed into the biochemical pool again to convert residual ammonia nitrogen into nitrate nitrogen. Clean breeding water quality and safety of breeding objects are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of aquaculture technology, and in particular to an integrated fermentation and denitrification / phosphorus removal system for the recycling of aquaculture wastewater. Background Technology

[0002] In existing recirculating aquaculture systems, the wastewater generated by microfiltration backwashing accounts for 5-10% of the total system volume daily. Furthermore, as the aquaculture process continues, nitrates and phosphates accumulate in the water, with nitrate nitrogen concentrations reaching over 500 mg / L in high-density tilapia farming systems. The indiscriminate discharge of microfiltration backwashing wastewater not only causes eutrophication of the surrounding water environment but also removes heat energy from the aquaculture water, increasing heating energy consumption during the aquaculture process. The backwashing wastewater contains a large amount of feces and uneaten feed, rich in starch, cellulose, and protein. Anaerobic fermentation of this wastewater produces a large amount of volatile fatty acids, which can provide electron donors for the denitrification process. Ferrous polysulfate is a commonly used flocculant in tap water treatment. Through coagulation-flocculation, it can effectively remove fine organic particles from the water, reducing COD. Simultaneously, Fe ions can combine with phosphate ions in the water to form insoluble ferric phosphate, achieving phosphorus removal from the aquaculture water. Currently, most existing recirculating aquaculture systems lack denitrification and phosphorus removal devices, resulting in large water exchange volumes, high energy consumption for circulation and heating during system operation, and the added value of the farmed organisms cannot offset the operating costs of the recirculating aquaculture system, making it impossible to promote it on a large scale.

[0003] Therefore, there is an urgent need for an integrated fermentation and denitrification / phosphorus removal system for the recycling of aquaculture wastewater to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide an integrated fermentation and denitrification / phosphorus removal system for the recycling of aquaculture wastewater, in order to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following solution: The present invention provides an integrated fermentation and denitrification / phosphorus removal aquaculture wastewater recycling system, comprising:

[0006] The aquaculture pond is connected to the inlet of the microfilter. The water in the aquaculture pond is filtered by the microfilter and then transported to the biological tank, which is connected to the aquaculture pond.

[0007] The treatment component includes a fermentation unit and a denitrification and phosphorus removal unit. The fermentation unit is connected to the drain outlet of the microfilter. The fermentation unit is used to ferment the wastewater generated by the backwashing of the microfilter. The fermented liquid and the water in the biological tank are both transported to the denitrification and phosphorus removal unit for denitrification and phosphorus removal. The supernatant in the phosphorus removal unit is transported back to the biological tank to convert residual ammonia nitrogen into nitrate nitrogen.

[0008] According to the present invention, an integrated fermentation and denitrification / phosphorus removal aquaculture wastewater recycling system is provided, wherein the fermentation component includes a fermentation tank and a fermentation liquid storage tank, the fermentation tank is connected to the drain outlet of the microfilter, and the fermentation tank is connected to the fermentation liquid storage tank through a first electromagnetic pump.

[0009] According to the present invention, an integrated fermentation and denitrification / phosphorus removal aquaculture wastewater recycling system is provided. The denitrification / phosphorus removal components include a denitrification tank and a phosphorus removal tank. The denitrification tank is connected to the fermentation liquid storage tank via a second electromagnetic pump. The denitrification tank is connected to the phosphorus removal tank via a third electromagnetic pump. The phosphorus removal tank is connected to the biological treatment tank via a fourth electromagnetic pump. The biological treatment tank is connected to the denitrification tank via a second submersible pump.

[0010] The integrated fermentation and denitrification / phosphorus removal aquaculture wastewater recycling system provided by the present invention further includes a ferric sulfate storage tank, which is connected to the phosphorus removal tank via a peristaltic pump.

[0011] The integrated fermentation and denitrification / phosphorus removal aquaculture wastewater recycling system provided by the present invention further includes a pump tank, which is connected to the inlet of the microfilter via a first submersible pump.

[0012] According to the present invention, an integrated fermentation and denitrification / phosphorus removal aquaculture wastewater recycling system is provided, wherein the fermentation tank, the denitrification tank, the phosphorus removal tank, and the polyferric sulfate storage tank are all equipped with stirring devices.

[0013] According to the present invention, an integrated fermentation and denitrification / phosphorus removal aquaculture wastewater recycling system is provided, wherein the fermentation tank, the fermentation liquid storage tank, the denitrification tank and the phosphorus removal tank are all equipped with limit floats.

[0014] According to the present invention, an integrated fermentation and denitrification / phosphorus removal aquaculture wastewater recycling system is provided, wherein the outlet pipe of the biological treatment tank is attached to the upper wall of the aquaculture tank, and the outlet pipe of the microfilter is attached to the upper wall of the biological treatment tank.

[0015] According to the present invention, an integrated fermentation and denitrification / phosphorus removal aquaculture wastewater recycling system is provided. The volume of the fermentation tank is 1 / 20 of the volume of the aquaculture pond. Every 8 hours, the first submersible pump and the stirring equipment in the fermentation tank automatically stop running for 20 minutes, during which 15 minutes are allowed to settle. After the settling is completed, the first electromagnetic pump runs for 3 minutes to pump the fermentation liquid into the fermentation liquid storage tank.

[0016] According to the present invention, an integrated fermentation and denitrification / phosphorus removal aquaculture wastewater recycling system is provided, wherein the capacity of the denitrification tank is 1 / 10 of the capacity of the aquaculture pond, the denitrification tank is provided with denitrification particles, and the system intermittently receives water injection from the second submersible pump and fermentation liquid injection from the second electromagnetic pump, with the injection water volume to fermentation liquid volume ratio being 9:1, and the running time of the second submersible pump and the second electromagnetic pump being 5 minutes.

[0017] Compared with the prior art, the present invention has the following advantages and technical effects:

[0018] This invention provides an integrated fermentation and denitrification / phosphorus removal wastewater recycling system for aquaculture. During operation, water from the aquaculture pond is transported to a microfilter for filtration and then returned to the pond. Simultaneously, the backwash wastewater from the microfilter undergoes fermentation in a fermenter and is then treated again by the denitrification / phosphorus removal unit before being returned to the aquaculture pond. This invention can denitrify and remove phosphorus from the aquaculture pond water once daily. Using this wastewater recycling device, the daily aquaculture wastewater volume can be reduced to below 0.5%, and over 95% of the backwash wastewater from the microfilter can be recycled and reused. Furthermore, during the aquaculture process, the concentrations of nitrate and reactive phosphorus in the aquaculture water can be maintained below 10 mg / L and 0.2 mg / L, respectively, thereby maximizing the cleanliness of the aquaculture water and the safety of the aquaculture organisms. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0021] The components include: 1. Aquaculture pond; 2. Pump tank; 3. Microfilter; 4. Biochemical tank; 5. Fermentation tank; 6. Fermentation liquid storage tank; 7. First electromagnetic pump; 8. Denitrification tank; 9. Phosphorus removal tank; 10. Second electromagnetic pump; 11. Third electromagnetic pump; 12. Fourth electromagnetic pump; 13. Second submersible pump; 14. Polyferric sulfate storage tank; 15. Peristaltic pump; and 16. First submersible pump. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Reference Figure 1 This invention provides an integrated fermentation and denitrification / phosphorus removal aquaculture wastewater recycling system, comprising:

[0025] Aquaculture pond 1 is connected to the inlet of microfilter 3. The water in aquaculture pond 1 is filtered by microfilter 3 and then transported to biological pond 4. Biological pond 4 is connected to aquaculture pond 1.

[0026] The treatment components include a fermentation unit and a denitrification and phosphorus removal unit. The fermentation unit is connected to the drain outlet of the microfilter 3. The fermentation unit is used to ferment the wastewater generated by the backwashing of the microfilter 3. The fermented liquid and the water in the biological tank 4 are both transported to the denitrification and phosphorus removal unit for denitrification and phosphorus removal. The supernatant in the phosphorus removal unit is transported back to the biological tank 4 to convert the residual ammonia nitrogen into nitrate nitrogen.

[0027] In one embodiment of the present invention, during use, the water in the aquaculture pond 1 is transported to the microfilter 3 for filtration and then transported back to the aquaculture pond 1. Simultaneously, the wastewater from the backwashing of the microfilter 3 is fermented in a fermentation tank and then transported again to the denitrification and phosphorus removal unit for treatment before being returned to the aquaculture pond 1. The water in the aquaculture pond 1 can be denitrified and dephosphorized once daily. Using this wastewater recycling device, the daily volume of aquaculture wastewater can be reduced to below 0.5%, and over 95% of the backwashing wastewater from the microfilter 3 can be recycled and reused. Furthermore, during the aquaculture process, the concentrations of nitrate and reactive phosphorus in the aquaculture water can be maintained below 10 mg / L and 0.2 mg / L, respectively, thereby maximizing the cleanliness of the aquaculture water and the safety of the aquaculture organisms.

[0028] As an optional implementation, the fermentation unit includes a fermenter 5 and a fermentation broth storage tank 6. The fermenter 5 is connected to the drain port of the microfilter 3, and the fermenter 5 is connected to the fermentation broth storage tank 6 through a first electromagnetic pump 7.

[0029] In one embodiment of the present invention, the wastewater generated by the backwashing of the microfilter 3 enters the fermentation tank 5 through the drain outlet. The volume of the fermentation tank 5 is 1 / 20 of the volume of the aquaculture pond 1. The fermentation tank 5 has a conical funnel structure at the bottom. The fermentation tank 5 continuously receives the waste generated by the backwashing of the microfilter 3 and is periodically inoculated with nitrifying bacteria, mainly composed of Nitrosomonas (ammonia-oxidizing bacteria) and Nitrospria (nitrite-oxidizing bacteria), along with yeast and Bacillus. The main function of the nitrifying bacteria is to rapidly consume the dissolved oxygen in the backwash water of the microfilter 3, converting ammonia nitrogen into nitrite nitrogen. At the same time, it ensures that the water in the fermentation tank 5 is at an oxygen-deficient level (DO < 0.2 mg / L). Under an oxygen-deficient state, the yeast and Bacillus convert feces and uneaten feed organic matter into volatile fatty acids.

[0030] As an optional implementation, the denitrification and phosphorus removal components include a denitrification tank 8 and a phosphorus removal tank 9. The denitrification tank 8 is connected to the fermentation broth storage tank 6 via a second electromagnetic pump 10, and the denitrification tank 8 is connected to the phosphorus removal tank 9 via a third electromagnetic pump 11. The phosphorus removal tank 9 is connected to the biological treatment tank 4 via a fourth electromagnetic pump 12, and the biological treatment tank 4 is connected to the denitrification tank 8 via a second submersible pump 13.

[0031] In one embodiment of the present invention, this setup constructs a clear, tiered water treatment chain. The denitrification tank is specifically responsible for converting nitrates and nitrites into nitrogen gas using the carbon source in the fermentation broth, thus completing denitrification; the phosphorus removal tank is specifically responsible for removing phosphates through chemical flocculation and precipitation. The two tanks are connected by a pump, enabling the water to automatically enter the phosphorus removal stage after denitrification. The process is smooth, the treatment objective is clear, and the efficient and synergistic removal of nitrogen and phosphorus pollutants is guaranteed.

[0032] As an optional implementation, it also includes a polyferric sulfate storage tank 14, which is connected to the dephosphorization tank 9 via a peristaltic pump 15.

[0033] In one embodiment of the present invention, polyferric sulfate is added by a peristaltic pump 15.

[0034] As an optional implementation, it also includes a pump pool 2, which is connected to the inlet of the microfilter 3 via a first submersible pump 16.

[0035] In one embodiment of the present invention, a dedicated pump pool 2 is provided as the hydraulic hub for system circulation, which can effectively buffer water level fluctuations and provide stable water intake conditions for the first submersible pump 16. This protects the pump and prevents eddies caused by direct water pumping from the aquaculture pond or stress to the cultured organisms, thereby improving the reliability and safety of system operation.

[0036] As an optional implementation, the fermenter 5, the denitrification tank 8, the phosphorus removal tank 9, and the polyferric sulfate storage tank 14 are all equipped with stirring equipment.

[0037] In one embodiment of the present invention, stirring devices are installed in each core reaction tank to ensure uniform mixing of the reactants. In fermentation tank 5, stirring ensures full contact between microorganisms and organic matter, improving fermentation efficiency; in denitrification tank 8, stirring ensures uniform mixing of carbon source and wastewater, increasing the denitrification rate; in phosphorus removal tank 9, stirring accelerates the diffusion and reaction of ferric polysulfate; and in ferric polysulfate storage tank 14, stirring prevents reagent precipitation. This comprehensively ensures the reaction effect of each unit.

[0038] As an optional implementation, limit floats are installed in fermenter 5, fermentation broth storage tank 6, denitrification tank 8 and phosphorus removal tank 9.

[0039] In one embodiment of the present invention, a limiting float is installed inside the critical tank and linked with the PLC control system to achieve automatic monitoring and safety interlocking of the liquid level. When the liquid level is too high, the feed pump can be automatically stopped and an alarm can be triggered, effectively preventing equipment failure, operational chaos, and environmental problems caused by tank overflow, and greatly improving the automation level and operational safety of the system.

[0040] As an optional implementation, the outlet pipe of the biological tank 4 is attached to the upper wall of the aquaculture tank 1, and the outlet pipe of the microfilter 3 is attached to the upper wall of the biological tank 4.

[0041] In one embodiment of the present invention, the water outlet pipe position is set to ensure that the water level difference between the aquaculture water level and the microfiltration machine water level is at the lowest possible level, thereby achieving a circulating energy-saving effect.

[0042] As an optional implementation, the volume of fermentation tank 5 is 1 / 20 of the volume of aquaculture pond 1. Every 8 hours, the first submersible pump 16 and the stirring equipment in fermentation tank 5 automatically stop running for 20 minutes, including 15 minutes of settling. After settling, the first electromagnetic pump 7 runs for 3 minutes to pump the fermentation liquid into fermentation liquid storage tank 6.

[0043] In one embodiment of the present invention, when the fermenter 5 receives backwash wastewater from the microfilter 3, the motor of the stirring device inside the fermenter 5 is in operation at a speed of 100-150 rpm. A limit float is installed inside the fermenter 5. If the water level in the fermenter touches the float, the first submersible pump 16 and the stirring motor stop rotating and an alarm is triggered. After the operating parameters are manually adjusted, the first submersible pump 16 and the stirring motor will continue to operate, thereby ensuring that the water in the fermenter 5 will not overflow. Under normal circumstances, every 8 hours, the first submersible pump 16 and the stirring motor automatically stop running for 20 minutes, including 15 minutes of settling. After the settling is completed, the first electromagnetic pump 7 runs for 3 minutes to pump the fermentation liquid into the fermentation liquid storage tank 6 for later use.

[0044] As an optional implementation, the capacity of the denitrification tank 8 is 1 / 10 of the capacity of the aquaculture pond 1. The denitrification tank 8 is equipped with denitrification particles and intermittently receives water from the second submersible pump 13 and fermentation liquid from the second electromagnetic pump 10. The ratio of the injected water volume to the fermentation liquid volume is 9:1, and the running time of the second submersible pump 13 and the second electromagnetic pump 10 is 5 minutes.

[0045] In one embodiment of the present invention, the capacity of the denitrification tank 8 is 1 / 10 of the capacity of the aquaculture pond 1. Denitrification particles are installed inside the denitrification tank 8, occupying 1 / 3 of its volume. It intermittently receives water from the second submersible pump 13 and anaerobic fermentation liquid, with a water-to-fermentation liquid volume ratio of approximately 9:1 each time. The water injection time of the second submersible pump 13 and the operating time of the second electromagnetic pump 10 are 5 minutes. To prevent water overflow, a limiting float is installed inside the denitrification tank 8. When the water level is too high and touches the float, the second submersible pump 13 and the second electromagnetic pump 10 stop working and trigger an alarm. After manual inspection and adjustment of the submersible pump operating parameters, operation resumes. Under normal circumstances, the denitrification working time is 30 minutes, followed by a 15-minute settling period, controlled by a PLC.

[0046] When the denitrification tank 8 has settled, the third electromagnetic pump 11 starts working for 5 minutes, pumping the supernatant (1 / 2 denitrified aquaculture water) from the denitrification tank 8 into the phosphorus removal tank 9. The phosphorus removal tank 9 consists of a cylindrical and a conical structure. The volume of the cylindrical structure is half the volume of the denitrification tank 8, which is sufficient to accept one batch of denitrified aquaculture water from the denitrification tank 8. The running time of the stirring equipment and the peristaltic pump 15 for injecting polyferric sulfate in the phosphorus removal tank 9 is 3 minutes. In the dephosphorus removal tank, the polyferric sulfate solution has a mass fraction of 10%, and the final concentration of polyferric sulfate is 10-20 mg / L each time it is injected. Then, it is allowed to settle and precipitate. The ferric phosphate and flocs settle into the cone of the dephosphorus removal tank 9. The settling time is 15 minutes. Then, the supernatant is pumped back to the biological treatment tank 4 by the fourth electromagnetic pump 12. In the biological treatment tank 4, the residual ammonia nitrogen is converted into nitrate nitrogen. Then, it flows into the aquaculture tank 1 to realize the recycling of aquaculture water. Thus, a denitrification and phosphorus removal process is completed.

[0047] In one embodiment of the present invention, the aquaculture pond 1 has a volume of 2 cubic meters of water, the microfiltration machine 3 can filter up to 5 cubic meters of water per hour, the biological treatment pond 4 has a volume of 200L and contains 50% K5 suspended filter media, the pump pond 2 has a volume of 100L, the fermentation tank 5 has a volume of 100L, the fermentation liquid storage tank 6 has a volume of 100L, the denitrification tank 8 has a volume of 200L, the phosphorus removal tank 9 has a volume of 140L, the polyferric sulfate storage tank 14 has a volume of 5L, and the submersible pumps all have a power of 50W. A PLC control device is used. The pump pond 2 is connected to the aquaculture pond 1 via a pipeline. The water in the pump pond 2 is lifted first and then enters the microfiltration machine 3. The filtered aquaculture water enters the biological treatment pond 4, and then enters the aquaculture pond 1.

[0048] Wastewater from the backwashing of microfilter 3 enters fermenter 5 through the drain outlet. Fermenter 5 continuously receives waste from the backwashing of microfilter 3 and is inoculated with nitrifying bacteria, yeast, and Bacillus every 7 days at inoculation amounts of 200mL, 100g, and 100g, respectively. Testing shows that the water in fermenter 5 is at an anoxic level (DO < 0.2mg / L). Under anoxic conditions, yeast and Bacillus convert feces and uneaten feed organic matter into volatile fatty acids. Denitrification tank 8 contains denitrification granules and receives water and anaerobic fermentation liquid from the second submersible pump 13 every 50 minutes. Under normal circumstances, denitrification takes 30 minutes, followed by 15 minutes of settling. The operating cycles of the second submersible pump 13 and the second electromagnetic pump 10 are controlled by a PLC setting.

[0049] When the denitrification tank 8 has settled, the third electromagnetic pump 11 starts working, operating for approximately 5 minutes, pumping the supernatant from the denitrification tank 8 into the phosphorus removal tank 9. The phosphorus removal tank 9 consists of a cylindrical and a conical section. The cylindrical section has a volume of 100L and contains a 10% polyferric sulfate solution. Each injection into the phosphorus removal tank results in a final polyferric sulfate concentration of 10-20 mg / L. The solution is then allowed to settle, with ferric phosphate and flocs settling into the conical section of the phosphorus removal tank 9 for 15 minutes. The supernatant is then pumped back to the biological treatment tank 4 via the fourth electromagnetic pump 12. In the biological treatment tank 4, residual ammonia nitrogen is converted into nitrate nitrogen, which then flows into the aquaculture tank 1 for water recycling. This completes one denitrification and phosphorus removal process. The denitrification tank 8 and the phosphorus removal tank 9 then proceed to the next water treatment process. The aquaculture tank 1 can be denitrified and phosphorus removed once daily. Using this wastewater recycling device, the daily aquaculture wastewater volume can be reduced to below 0.3%, and 97% of the backwash wastewater from the microfilter 3 can be recycled and reused. In pond 1, the tilapia biomass is 50 kg, and the aquaculture process lasts for 2 months. During this period, the concentrations of nitrate and reactive phosphorus in the aquaculture water can be maintained below 8 mg / L and 0.2 mg / L, respectively, and the water quality remains crystal clear.

[0050] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0051] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An integrated fermentation and denitrification and dephosphorization aquaculture effluent recycling treatment system, characterized in that, The application relates to a water treatment system for aquaculture, which comprises: a culture pond (1) in communication with the water inlet of a microfilter (3), wherein the water in the culture pond (1) is filtered by the microfilter (3) and then delivered into a biochemical pond (4) in communication with the culture pond (1); a treatment assembly comprising a fermentation part and a denitrification and phosphorus removal part, wherein the fermentation part is in communication with the blow-off port of the microfilter (3) and is used for fermenting the wastewater generated by backwashing of the microfilter (3), the fermented fermentation liquid and the water in the biochemical pond (4) are delivered into the denitrification and phosphorus removal part for denitrification and phosphorus removal treatment, and the supernatant in the phosphorus removal part is delivered into the biochemical pond (4) again to convert residual ammonia nitrogen into nitrate nitrogen.

2. The integrated fermentation and denitrification and dephosphorization aquaculture tail water recycling treatment system according to claim 1, characterized in that: The fermentation part comprises a fermentation tank (5) and a fermentation liquid storage tank (6), the fermentation tank (5) is in communication with the blow-off port of the microfilter (3), and the fermentation tank (5) is in communication with the fermentation liquid storage tank (6) through a first electromagnetic pump (7).

3. The integrated fermentation and denitrification and phosphorus removal aquaculture effluent recycling system according to claim 2, characterized in that: The denitrification and phosphorus removal part comprises a denitrification and phosphorus removal tank body (8) and a phosphorus removal tank body (9), the denitrification and phosphorus removal tank body (8) is in communication with the fermentation liquid storage tank (6) through a second electromagnetic pump (10), the denitrification and phosphorus removal tank body (8) is in communication with the phosphorus removal tank body (9) through a third electromagnetic pump (11), the phosphorus removal tank body (9) is in communication with the biochemical pond (4) through a fourth electromagnetic pump (12), and the biochemical pond (4) is in communication with the denitrification and phosphorus removal tank body (8) through a second submersible pump (13).

4. The integrated fermentation and denitrification and dephosphorization aquaculture tail water recycling treatment system according to claim 3, characterized in that: A poly ferric sulfate storage tank (14) is further arranged and is in communication with the phosphorus removal tank body (9) through a peristaltic pump (15).

5. The integrated fermentation and denitrification and phosphorus removal aquaculture effluent recycling system according to claim 3, characterized in that: A pump pond (2) is further arranged and is in communication with the water inlet of the microfilter (3) through a first submersible pump (16).

6. The integrated fermentation and denitrification and dephosphorization aquaculture effluent recycling treatment system according to claim 4, characterized in that: Stirring devices are arranged in the fermentation tank (5), the denitrification and phosphorus removal tank body (8), the phosphorus removal tank body (9) and the poly ferric sulfate storage tank (14).

7. The integrated fermentation and denitrification and dephosphorization aquaculture effluent recycling treatment system according to claim 3, characterized in that: Limiting floating balls are arranged in the fermentation tank (5), the fermentation liquid storage tank (6), the denitrification and phosphorus removal tank body (8) and the phosphorus removal tank body (9).

8. The integrated fermentation and denitrification and dephosphorization aquaculture tail water recycling treatment system according to claim 1, characterized in that: The water outlet pipeline of the biochemical pond (4) is attached above the wall of the culture pond (1), and the water outlet pipeline of the microfilter (3) is attached above the wall of the biochemical pond (4).

9. The integrated fermentation and denitrification and phosphorus removal aquaculture effluent recycling treatment system according to claim 5, characterized in that: The volume of the fermentation tank (5) is 1 / 20 of the volume of the culture pond (1), the first submersible pump (16) and the stirring device in the fermentation tank (5) are automatically stopped for 20 min every 8 h, wherein the standing and precipitation lasts for 15 min, after the standing and precipitation is completed, the first electromagnetic pump (7) is operated for 3 min to pump the fermentation liquid into the fermentation liquid storage tank (6).

10. The integrated fermentation and denitrification and phosphorus removal aquaculture effluent recycling treatment system according to claim 3, characterized in that: The volume of the denitrification and phosphorus removal tank body (8) is 1 / 10 of the volume of the culture pond (1), the denitrification and phosphorus removal tank body (8) is provided with denitrification particles and intermittently receives water injection of the second submersible pump (13) and fermentation liquid injection of the second electromagnetic pump (10), the water injection volume and the fermentation liquid volume ratio is 9:1, and the operation time of the second submersible pump (13) and the second electromagnetic pump (10) is 5 min.

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