A device and method for treating sewage by short-range denitrification in a circulating aquaculture system

Abstract

The present invention provides a device and method for short-range denitrification treatment of wastewater in a recirculating aquaculture system, belonging to the technical field of sturgeon aquaculture. The device includes an anaerobic tank, a disinfection tank, a clean water tank, a backup tank, a clean water inlet pipe, a fry rearing component, and a PLC control system. The outlet of the anaerobic tank is connected to the disinfection tank; the outlet of the disinfection tank is connected to the clean water tank; the backup tank is connected to the clean water tank; clean water in the clean water tank flows into the fry rearing component to replenish the dissolved oxygen in the fry rearing component and dilute metabolic waste. The wastewater in the fry rearing component is discharged into the anaerobic tank for denitrification treatment. The treated wastewater enters the disinfection tank for neutralization and then disinfection. The disinfected clean water flows into the clean water tank for aeration, increasing the oxygen content of the clean water and completing the water recycling. The present invention recycles wastewater from the artificial sturgeon aquaculture process, saving water resources, and the entire process is not affected by external factors.

Description

Technical Field

[0001] The invention belongs to the technical field of sturgeon breeding, and particularly relates to a device and method for treating sewage by short-range denitrification in a circulating aquaculture system. Background Art

[0002] Sturgeon is a very rare cold-water fish, renowned for its unique biological characteristics and significant economic value. Artificial breeding of sturgeons is a key means of protecting and utilizing this rare species. As natural sturgeon resources are nearing depletion, artificial breeding has become a key approach to saving the species. Primary breeding methods include collecting wild seedlings or using artificial propagation techniques for proliferation. The breeding process requires controlling environmental factors such as water temperature, dissolved oxygen, and water quality, and providing appropriate amounts of feed. Through careful management, sturgeons can complete their entire life cycle in an artificial environment. Artificial breeding not only meets market demand for high-end aquatic products such as sturgeon roe (fish roe), but also reduces fishing pressure on wild populations, providing strong support for the protection and recovery of endangered populations.

[0003] Currently, sturgeon aquaculture primarily relies on flow-through aquaculture and cage culture. Flow-through aquaculture uses high-quality spring or river water as a water source. Mechanical water extraction or the use of natural terrain gradients maintains a suitable flow rate and volume within the pond, and water is not reused. This model offers advantages such as low cost and ease of management. However, it suffers from environmental influences, poor controllability, and environmental pollution from wastewater. Cage aquaculture utilizes large water bodies, such as reservoirs and large rivers, combined with intensive aquaculture within smaller cages. Its advantages include easy harvesting and high yields, but its disadvantages include significant environmental influences and the potential for water pollution. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a device and method for short-range denitrification treatment of sewage in a recirculating aquaculture system, which can promptly treat the wastewater in aquaculture within a smaller range, effectively solving the problems in the existing technology that sturgeon artificial breeding is easily affected by the external environment, has poor controllability, and the drainage outside the breeding area is easy to pollute the environment.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a device for short-range denitrification treatment of sewage in a circulating aquaculture system, comprising an anaerobic tank, a disinfection tank, sturgeons to be reared, a clean water tank, a standby tank, a clean water inlet pipe, a fry rearing component and a PLC control system; the outlet end of the anaerobic tank is connected to the disinfection tank; the outlet end of the disinfection tank is connected to the clean water tank; the standby tank is connected to the clean water tank; the clean water in the clean water tank flows into the fry rearing component through the clean water inlet pipe to replenish the dissolved oxygen in the fry rearing component and dilute metabolic waste; the wastewater in the fry rearing component is discharged into the anaerobic tank for denitrification treatment; the treated sewage enters the disinfection tank, is first neutralized and then disinfected; the clean water after disinfection flows into the clean water tank for aeration to increase the oxygen content of the clean water, thereby completing the water recycling.

[0006] Preferably, the anaerobic tank includes an anaerobic tank body, an anaerobic tank water inlet pipe, a supporting layer, a biological filler layer and an anaerobic tank drainage pipe. The anaerobic tank water inlet pipe and the anaerobic tank drainage pipe are both connected to the anaerobic tank body, the supporting layer and the biological filler layer are both located inside the anaerobic tank body, the biological filler layer is located on the top of the supporting layer, a first water pump is provided on the anaerobic tank drainage pipe, and a first stop valve is provided on the outlet pipe of the disinfection tank.

[0007] Preferably, the clear water tank includes a clear water tank body, a first liquid level sensor, a water supply pipe, a bypass pipe and a clear water tank drainage pipe. The first liquid level sensor is located on the front of the clear water tank body. The water supply pipe and the clear water tank drainage pipe are both communicated with the clear water tank body. The bypass pipe is located at the bottom of the clear water tank body and is communicated with it. A first solenoid valve is provided on the water supply pipe, a second solenoid valve is provided on the bypass pipe, and a second stop valve is provided on the clear water tank drainage pipe. The standby tank includes a standby tank body, a second liquid level sensor and a standby tank drainage pipe. The second liquid level sensor is located on the front of the standby tank body. A second water pump and a standby tank one-way valve are provided on the standby tank drainage pipe.

[0008] Preferably, the clean water inlet pipe includes a U-shaped main water inlet pipe, a first branch water inlet pipe, a second branch water inlet pipe, a third branch water inlet pipe and a fourth branch water inlet pipe. The first branch water inlet pipe, the second branch water inlet pipe, the third branch water inlet pipe and the fourth branch water inlet pipe are all connected to the U-shaped main water inlet pipe, the first branch water inlet pipe is on a third stop valve, the second branch water inlet pipe is on a fourth stop valve, the third branch water inlet pipe is on a fifth stop valve, and the fourth branch water inlet pipe is on a sixth stop valve.

[0009] Preferably, the fry rearing assembly includes a breeding box assembly, a blocking pipe assembly, a lifting assembly and a breeding box drainage pipe, the movable box on the top of the lifting assembly is located inside the breeding box assembly, the fixed box on the top of the breeding box drainage pipe is located inside the breeding box assembly, the blocking pipe assembly is located inside the breeding box assembly, and the movable box is located on the top of the fixed box.

[0010] Preferably, the breeding box assembly includes a breeding box shell, a partition plate and a card plate assembly, the partition plate is located inside the breeding box shell, a first through hole and a second through hole are provided on the bottom plate of the breeding box shell, a partition opening is provided on the partition plate, three sides of the partition opening are provided with a first groove, the card plate assembly is engaged in the partition opening, the card plate assembly includes a pull-out plate and a handle, the handle is located on the top of the pull-out plate and is fixedly connected thereto; the partition plate, the mobile box and the breeding box shell divide the fry breeding assembly into four areas A, B, C and D.

[0011] Preferably, a third through hole is provided at the center of the blocking tube assembly, the blocking tube assembly includes a blocking tube and a connecting end plate, a fourth through hole and a second groove are provided on the connecting end plate, and the end of the blocking tube away from the connecting end plate is a tapered end.

[0012] Preferably, the flow rate V1 of water passing through a single branch inlet pipe of the clean water inlet pipe, the discharge flow rate V2 of water passing only through the fourth through holes of the two blocking pipe assemblies, and the discharge flow rate V3 of water passing through the fourth through holes and the third through holes of the two blocking pipe assemblies at the same time have the following relationship: V2<V1<V3.

[0013] Preferably, the lifting assembly also includes an electric cylinder assembly, the moving box is located on the top of the electric cylinder assembly and is fixedly connected thereto, a fifth through hole is provided around the box body of the moving box, a sixth through hole is provided on the bottom plate of the moving box, the drainage pipe of the breeding box also includes a U-shaped main water outlet pipe, a seventh through hole and an eighth through hole are provided on the bottom plate of the fixed box, and a tapered mouth corresponding to the tapered end is provided on the pipe of the U-shaped main water outlet pipe.

[0014] The present invention also provides a method for using the above device, which includes a sturgeon transfer method S1, a water circulation method S2, and a method for maintaining the water level in a clear water tank S3;

[0015] The sturgeon transfer method S1 includes the following steps:

[0016] S11, placing clean water in the four areas A, B, C, and D of the fry rearing assembly, at which point the clean water cannot flow out through the fourth through hole, and placing sturgeons to be reared in the D area, C area, and B area of ​​the fry rearing assembly at preset time intervals;

[0017] S12, placing feed in the area where sturgeons are present, wherein undigested food residues and sturgeon feces will sink to the bottom of the mobile box in the corresponding area;

[0018] S13, after a preset time, the third stop valve above area A of the fry rearing assembly is opened and the sixth stop valve above area D is closed. The electric cylinder assembly below area D of the fry rearing assembly is lifted until the movable box in that area abuts against the connecting end plate. The water level in area D then drops and is discharged through the third through-hole. A portion of the water flows directly into the anaerobic tank through the drainage pipe of the breeding tank, and a portion of the water flows through the fourth through-hole into the area between the movable box and the fixed box. When the water level in area D drops to a preset value, the clamping plate assembly between area D and area A is raised, and the sturgeons and a small amount of water enter area A.

[0019] S14, resetting the pallet assembly between area D and area A, and pumping the food residue and sturgeon feces in the mobile box into a designated location for composting by using a mud pump;

[0020] S15, continue to lift the electric cylinder assembly under area D, so that the blocking pipe assembly is completely separated from the drainage pipe of the breeding tank, and the water between the movable box and the fixed box enters the anaerobic tank through the drainage pipe of the breeding tank;

[0021] S16, resetting the electric cylinder assembly in area D and injecting clean water into area D. At this time, the clean water cannot flow out through the fourth through hole;

[0022] S17, sequentially moving the sturgeons in area C to area D and cleaning area C, moving the sturgeons in area B to area C and cleaning area B, and moving the sturgeons in area A to area B and cleaning area A at preset time intervals;

[0023] The water recycling method S2 comprises the following steps:

[0024] S21, the wastewater in the anaerobic tank is denitrified, further purified through the biological filler layer, and then pumped into the disinfection tank;

[0025] S22, the water in the disinfection tank is neutralized and then disinfected, and the clean water after disinfection flows into the clean water tank;

[0026] S23, aerating the water in the clean water tank to increase the oxygen content of the clean water and provide a water source for the fry rearing component;

[0027] The water level in the clean water tank is automatically controlled by the liquid level sensor and PLC control system;

[0028] The method S3 for maintaining the water level in the clear water tank comprises the following steps:

[0029] S31, when the water level in the clean water tank is higher than the high value set by the first liquid level sensor, the first liquid level sensor feeds back a signal to the PLC control system, which opens the second solenoid valve, and the clean water in the clean water tank flows into the standby tank. When the water level in the clean water tank drops and falls below the high value set by the first liquid level sensor, the second solenoid valve is closed;

[0030] S32, when the water level in the clear water tank is lower than the low value set by the first liquid level sensor, the first liquid level sensor feeds back a signal to the PLC control system, and the liquid level of the second liquid level sensor is judged at this time;

[0031] S321, if the liquid level in the standby tank is higher than the low value set by the second liquid level sensor, start the second water pump to pump the clean water from the standby tank into the clean water tank. When the water level in the clean water tank rises and is higher than the low value set by the first liquid level sensor, stop the second water pump.

[0032] S322, if the liquid level in the standby tank is lower than the low value set by the second liquid level sensor, open the first solenoid valve and replenish water into the clean water tank through the water replenishment pipe. When the water level in the clean water tank rises and is higher than the low value set by the first liquid level sensor, close the first solenoid valve.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention provides a device for short-range denitrification treatment of sewage in a circulating aquaculture system. By configuring an anaerobic tank, a disinfection tank, a clean water tank, a standby tank, a clean water inlet pipe, a fry rearing component, and a PLC control system, the device recycles wastewater from the artificial breeding process of sturgeons, thereby saving water resources and preventing the entire process from being affected by the outside world.

[0035] The present invention provides a device for short-range denitrification treatment of sewage in a recirculating aquaculture system. During the aquaculture process, the water inlet flow rate V1 is greater than the discharge flow rate V2 through the fourth through hole alone. The continuous inflow of fresh water and discharge of wastewater ensure the water quality of the sturgeon area, which is conducive to the healthy growth of the sturgeons and improves the aquaculture efficiency. At the same time, food residues (including uneaten feed) and sturgeon feces generated during the aquaculture process are centrally cleaned, reducing the ammonia nitrogen content of the wastewater entering the anaerobic tank and the difficulty of denitrification treatment. In addition, a biological filler layer is provided in the anaerobic tank to ensure the effluent water quality.

[0036] The present invention provides a device for short-range denitrification treatment of wastewater in a recirculating aquaculture system. This device breaks the traditional sturgeon cage culture method in which fry to adult fish are kept in a fixed area. A transfer area with a non-fixed location is set up, which can timely clean the fry feeding components, so that the sturgeons can always live in a high-quality breeding environment.

[0037] The present invention provides a device for short-range denitrification treatment of sewage in a circulating aquaculture system. The water level in the clear water tank can be automatically maintained within a reasonable range, ensuring sufficient water supply in the fry breeding component. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is an overall schematic diagram of the present invention;

[0039] Figure 2 It is a schematic diagram of an anaerobic tank of the present invention;

[0040] Figure 3 It is a schematic diagram of a clear water tank of the present invention;

[0041] Figure 4 It is a structural schematic diagram of the clean water inlet pipe of the present invention;

[0042] Figure 5 This invention Figure 1 E-direction view;

[0043] Figure 6 is a three-dimensional schematic diagram of the fry rearing assembly of the present invention;

[0044] Figure 7 It is a schematic structural diagram of the breeding box assembly of the present invention;

[0045] Figure 8 It is a schematic structural diagram of the card board assembly of the present invention;

[0046] Figure 9 It is a schematic structural diagram of the plugging tube assembly of the present invention;

[0047] Figure 10 It is a schematic structural diagram of the lifting assembly of the present invention;

[0048] Figure 11 This is a schematic diagram of the drainage pipe structure of the aquaculture box of the present invention;

[0049] Figure 12 This is a schematic diagram of the internal structure of the fry rearing assembly of the present invention under normal rearing conditions;

[0050] Figure 13 This is a schematic diagram of the internal structure of the fry rearing assembly D region of the present invention when the movable box and the connecting end plate abut against each other;

[0051] Figure 14 1. It is a schematic diagram of the internal structure of the fry rearing assembly of the present invention when the connecting plate assembly in area D and area A is lifted;

[0052] Figure 15 This is a schematic diagram of the internal structure of the fry rearing assembly D area when the blocking pipe assembly is completely separated from the drainage pipe of the breeding box.

[0053] In the figure: 100, anaerobic tank; 110, anaerobic tank body; 120, anaerobic tank water inlet pipe; 130, support layer; 140, biological filler layer; 150, anaerobic tank drainage pipe; 151, first water pump; 200, disinfection tank; 201, first stop valve; 300, clean water tank; 310, clean water tank body; 320, first liquid level sensor; 330, water supply pipe; 331, first solenoid valve; 340, bypass pipe; 341 , second solenoid valve; 350, clean water tank drainage pipe; 351, second stop valve; 400, spare tank; 410, spare tank body; 420, second liquid level sensor; 430, spare tank drainage pipe; 431, second water pump; 432, spare tank one-way valve; 500, clean water inlet pipe; 510, U-shaped main inlet pipe; 520, first branch inlet pipe; 521, third stop valve; 530, second branch inlet pipe; 531, fourth cut-off valve Check valve; 540, third branch water inlet pipe; 541, fifth stop valve; 550, fourth branch water inlet pipe; 551, sixth stop valve; 600, breeding box assembly; 610, breeding box shell; 611, first through hole; 612, second through hole; 620, partition plate; 621, partition opening; 622, first groove; 630, card plate assembly; 631, pull-out plate; 632, pull-out boss; 633, handle; 700, plugging pipe assembly; 7 01, third through hole; 710, blocking tube; 711, fourth through hole; 712, second groove; 713, tapered end; 720, connecting end plate; 800, lifting assembly; 810, electric cylinder assembly; 820, moving box; 821, fifth through hole; 822, sixth through hole; 900, aquaculture box drainage pipe; 910, fixing box; 911, seventh through hole; 912, eighth through hole; 920, U-shaped main outlet pipe; 921, tapered mouth. DETAILED DESCRIPTION

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0055] It should be pointed out that the terms "upper", "lower", "left", "right", "top", "bottom", "inside", "outside" and the like indicating directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0056] It should be understood that, in the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense.

[0057] Example 1

[0058] See attached Figure 1 To the attached Figure 15 This embodiment provides a device for short-range denitrification treatment of sewage in a recirculating aquaculture system, including sturgeons to be raised, an anaerobic tank 100, a disinfection tank 200, a clean water tank 300, a spare tank 400, a clean water inlet pipe 500, a fry rearing component and a PLC control system.

[0059] The anaerobic tank 100 includes an anaerobic tank body 110, an anaerobic tank water inlet pipe 120, a supporting layer 130, a biological filler layer 140 and an anaerobic tank drainage pipe 150. The anaerobic tank water inlet pipe 120 and the anaerobic tank drainage pipe 150 are both connected to the anaerobic tank body 110. The anaerobic tank water inlet pipe 120 is located on one side of the anaerobic tank body 110, and the anaerobic tank drainage pipe 150 is located on the other side of the anaerobic tank body 110. The supporting layer 130 and the biological filler layer 140 are both located inside the anaerobic tank body 110, and the biological filler layer 140 is located on the top of the supporting layer 130. A first water pump 151 is provided on the anaerobic tank drainage pipe 150.

[0060] During the sturgeon breeding process, water is recycled and denitrified in the anaerobic tank 100 to remove nitrate and nitrite pollution from the water. Sturgeon breeding produces a large amount of wastewater containing high concentrations of nitrogen compounds (such as ammonia nitrogen, nitrate, and nitrite). Direct discharge of wastewater can lead to eutrophication of the water body and seriously disrupt the aquatic ecological balance. During the denitrification treatment in the anaerobic tank 100, anaerobic bacteria can reduce nitrates to nitrogen gas, thereby effectively removing excess nitrogen compounds from the water body, improving water quality, and avoiding eutrophication. Simultaneously, a biological filler layer 140 is provided in the anaerobic tank 100 to further improve the effluent quality. During sturgeon breeding, a large amount of high concentrations of nitrogen compounds is produced, mainly from sludge. The sludge is mainly composed of food residues (including uneaten feed) and sturgeon feces. Therefore, it is necessary to minimize the amount of sludge entering the anaerobic tank 100.

[0061] The outlet end of the anaerobic tank 100 is connected to the disinfection tank 200. A first stop valve 201 is provided on the outlet pipe of the disinfection tank 200. The outlet end of the disinfection tank 200 is connected to the clean water tank 300. After the water in the anaerobic tank 100 enters the disinfection tank 200, a neutralizer is first added to neutralize it so that its pH value is close to 7, and then a disinfectant is added for sterilization.

[0062] The clear water tank 300 includes a clear water tank body 310, a first liquid level sensor 320, a water supply pipe 330, a bypass pipe 340 and a clear water tank drainage pipe 350. The first liquid level sensor 320 is located on the front of the clear water tank body 310. The water supply pipe 330 and the clear water tank drainage pipe 350 are both connected to the clear water tank body 310. The water supply pipe 330 is located at the top of the clear water tank drainage pipe 350. The bypass pipe 340 is located at the bottom of the clear water tank body 310 and is connected thereto. A first solenoid valve 331 is provided on the water supply pipe 330, a second solenoid valve 341 is provided on the bypass pipe 340, and a second stop valve 351 is provided on the clear water tank drainage pipe 350. An aeration device (not shown in the figure) is usually provided in the clear water tank 300. The backup tank 400 is connected to the clean water tank 300. The backup tank 400 includes a backup tank body 410, a second liquid level sensor 420 and a backup tank drainage pipe 430. The second liquid level sensor 420 is located on the front of the backup tank body 410. The backup tank drainage pipe 430 is provided with a second water pump 431 and a backup tank one-way valve 432.

[0063] That is to say, the clean water in the clean water tank 300 flows into the fry breeding assembly through the clean water inlet pipe 500, replenishes the dissolved oxygen in the fry breeding assembly, dilutes metabolic waste, and the wastewater in the fry breeding assembly is discharged into the anaerobic tank 100 for denitrification treatment to reduce its nitrate and nitrite components. The treated wastewater enters the disinfection tank 200, is first neutralized and then disinfected. The clean water after disinfection flows into the clean water tank 300 for aeration to increase the oxygen content of the clean water, thereby completing the water recycling.

[0064] The clean water inlet pipe 500 includes a U-shaped main water inlet pipe 510, a first branch water inlet pipe 520, a second branch water inlet pipe 530, a third branch water inlet pipe 540 and a fourth branch water inlet pipe 550. The first branch water inlet pipe 520, the second branch water inlet pipe 530, the third branch water inlet pipe 540 and the fourth branch water inlet pipe 550 are all connected to the U-shaped main water inlet pipe 510, the third stop valve 521 is on the first branch water inlet pipe 520, the fourth stop valve 531 is on the second branch water inlet pipe 530, the fifth stop valve 541 is on the third branch water inlet pipe 540, and the sixth stop valve 551 is on the fourth branch water inlet pipe 550.

[0065] The fry breeding assembly includes a breeding box assembly 600, a sealing pipe assembly 700, a lifting assembly 800 and a breeding box drainage pipe 900. The movable box 820 on the top of the lifting assembly 800 is located inside the breeding box assembly 600, the fixed box 910 on the top of the breeding box drainage pipe 900 is located inside the breeding box assembly 600, the sealing pipe assembly 700 is located inside the breeding box assembly 600, and the movable box 820 is located on the top of the fixed box 910.

[0066] The breeding box assembly 600 includes a breeding box shell 610, a partition plate 620 and a card assembly 630. The main body of the partition plate 620 is a cross-shaped structure. The breeding box shell 610 is fixedly connected by a support (not shown in the figure). The partition plate 620 is located inside the breeding box shell 610. A first through hole 611 and a second through hole 612 are provided on the bottom plate of the breeding box shell 610. A partition opening 621 is provided on the partition plate 620. The three sides of the partition opening 621 are provided with a first groove 622. The card assembly 630 is engaged in the partition opening 621. The card assembly 630 includes a pull-out plate 631 and a handle 633. The three sides of the pull-out plate 631 are provided with a pull-out boss 632 corresponding to the first groove 622. The handle 633 is located at the top of the pull-out plate 631 and fixedly connected thereto; the partition plate 620, the mobile box 820 and the breeding box shell 610 divide the fry breeding assembly into four areas: A, B, C and D.

[0067] A third through hole 701 is provided at the center of the blocking tube assembly 700. The blocking tube assembly 700 includes a blocking tube 710 and a connecting end plate 720. The connecting end plate 720 is located at the top of the blocking tube 710 and is fixedly connected thereto. A fourth through hole 711 and a second groove 712 are provided on the connecting end plate 720. The second groove 712 is located at the bottom of the fourth through hole 711. The end of the blocking tube 710 away from the connecting end plate 720 is a tapered end 713. In order to better separate food residues and sturgeon feces in the sturgeon breeding area, a filter net is usually provided on the top surface of the third through hole 701, and a filter hole can also be provided on the side of the connecting end plate 720.

[0068] It should be pointed out that the flow rate V1 of water passing through a single branch inlet pipe of the clean water inlet pipe 500, the discharge flow rate V2 of water passing only through the fourth through hole 711 of the two blocking pipe assemblies 700, and the discharge flow rate V3 of water passing through the fourth through hole 711 and the third through hole 701 of the two blocking pipe assemblies 700 at the same time have the following relationship: V2<V1<V3.

[0069] The lifting assembly 800 also includes an electric cylinder assembly 810. The moving box 820 is located on the top of the electric cylinder assembly 810 and is fixedly connected to it. The moving box 820 is a square box body. A fifth through hole 821 is provided around the box body of the moving box 820. A sealing structure is provided between the protruding shaft of the electric cylinder assembly 810 and the moving box 820. A sixth through hole 822 is provided on the bottom plate of the moving box 820.

[0070] The drainage pipe 900 of the breeding box also includes a U-shaped main water outlet pipe 920. The fixing box 910 is a square box body. The bottom plate of the fixing box 910 is provided with a seventh through hole 911 and an eighth through hole 912. A sealing structure is provided between the protruding shaft of the electric cylinder assembly 810 and the eighth through hole 912. A tapered mouth 921 corresponding to the tapered end 713 is provided on the pipe of the U-shaped main water outlet pipe 920. When the sealing pipe assembly 700 is in working state, the sealing pipe assembly 700 passes through the sixth through hole 822 and the seventh through hole 911, and the sealing pipe assembly 700 is fixed by the cooperation of the tapered end 713 and the tapered mouth 921. The outer diameter of the protruding shaft of the electric cylinder assembly 810 is smaller than the aperture of the second through hole 612, and the U-shaped main water outlet pipe 920 passes through the first through hole 611.

[0071] The present invention also provides a method for using the lifting device, which includes a sturgeon transfer method S1, a water circulation method S2, and a method for maintaining the water level in a clear water tank S3;

[0072] The sturgeon transfer method S1 includes the following steps:

[0073] S11, clean water is placed in the four areas A, B, C, and D of the fry rearing assembly. At this time, the clean water cannot flow out through the fourth through hole 711. Sturgeons to be reared are placed in areas D, C, and B of the fry rearing assembly at preset time intervals. When a sturgeon is placed in each area, the stop valve at the top of the corresponding area is opened to allow clean water to flow in. Since V2 < V1 < V3, the water level in the area containing the sturgeons is maintained within a certain height range;

[0074] S12, feeding is placed in the area where the sturgeons are present, wherein undigested food residues (including uneaten feed) and sturgeon feces will sink to the bottom of the mobile box 820 in the corresponding area;

[0075] S13: After a preset time, the third stop valve 521 on area A of the fry rearing assembly is opened and the sixth stop valve 551 on area D is closed. The electric cylinder assembly 810 below area D of the fry rearing assembly is lifted until the movable box 820 in that area abuts against the connecting end plate 720. The water level in area D then drops and is discharged through the third through-hole 701. A portion of the water enters the anaerobic tank 100 directly through the drainage pipe 900 of the breeding tank, and a portion of the water falls into the area between the movable box 820 and the fixed box 910 through the fourth through-hole 711. When the water level in area D drops to a preset value, the clamping plate assembly 630 between area D and area A is raised, and the sturgeons and a small amount of water enter area A.

[0076] S14, when no liquid is discharged from the mobile box 820 in step S12, the card assembly 630 between the D area and the A area is reset, and the food residue (including uneaten feed) and sturgeon feces in the mobile box 820 are pumped into a designated location for composting by a mud pump (not shown);

[0077] S15, continue to lift the electric cylinder assembly 810 below the D area to completely separate the blocking pipe assembly 700 from the aquaculture tank drainage pipe 900, and the water between the movable box 820 and the fixed box 910 enters the anaerobic tank 100 through the aquaculture tank drainage pipe 900;

[0078] S16, when no liquid is discharged between the movable box 820 and the fixed box 910, the electric cylinder assembly 810 in area D is reset, and clean water is injected into area D. At this time, the clean water cannot flow out through the fourth through hole 711;

[0079] S17, sequentially moving the sturgeons in area C to area D and cleaning area C at preset time intervals, moving the sturgeons in area B to area C and cleaning area B, and moving the sturgeons in area A to area B and cleaning area A.

[0080] It should be noted that in order to reduce the possible damage to the sturgeons during the transfer process, the plugging pipe assembly 700 and the moving box 820 are usually made of non-metallic materials. In step S14, the mud pump is generally configured as a lifting mechanism, and its connecting platform can be rotated. As needed, the sludge in the area can be extracted to the designated location for mud storage by lifting and moving the connecting platform. Figure 14 In step S13, the card board assembly 630 can be completely separated from the partition plate 620 or partially separated.

[0081] The water recycling method S2 comprises the following steps:

[0082] S21, the wastewater in the anaerobic tank 100 is denitrified by anaerobic bacteria, further purified by the biological filler layer 140, and then pumped into the disinfection tank 200;

[0083] S22, the water in the disinfection tank 200 is neutralized and then disinfected, and the disinfected clean water flows into the clean water tank 300;

[0084] S23, aerating the water in the clean water tank 300 to increase the oxygen content of the clean water and provide a water source for the fry breeding assembly.

[0085] The water level in the clear water tank 300 is automatically controlled by a liquid level sensor and a PLC control system.

[0086] The method S3 for maintaining the water level in the clear water tank comprises the following steps:

[0087] S31, when the water level in the clean water tank 300 is higher than the high value set by the first liquid level sensor 320, the first liquid level sensor 320 feeds back a signal to the PLC control system, which opens the second solenoid valve 341, and the clean water in the clean water tank 300 flows into the backup tank 400. When the water level in the clean water tank 300 drops and falls below the high value set by the first liquid level sensor 320, the second solenoid valve 341 is closed;

[0088] S32, when the water level in the clear water tank 300 is lower than the low value set by the first liquid level sensor 320, the first liquid level sensor 320 feeds back a signal to the PLC control system, and the liquid level of the second liquid level sensor 420 is judged at this time;

[0089] S321, if the liquid level in the backup tank 400 is higher than the low value set by the second liquid level sensor 420, the second pump 431 is started to pump the clean water in the backup tank 400 into the clean water tank 300. When the water level in the clean water tank 300 rises and exceeds the low value set by the first liquid level sensor 320, the second pump 431 is turned off;

[0090] S322, if the liquid level in the backup tank 400 is lower than the low value set by the second liquid level sensor 420, open the first solenoid valve 331 and replenish water into the clean water tank 300 through the water replenishment pipe 330. When the water level in the clean water tank 300 rises and is higher than the low value set by the first liquid level sensor 320, close the first solenoid valve 331.

[0091] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A device for treating wastewater by short-range denitrification in a circulating aquaculture system, comprising an anaerobic tank (100), a disinfection tank (200), and sturgeons to be reared, characterized in that: It also includes a clean water tank (300), a standby tank (400), a clean water inlet pipe (500), a fry rearing component and a PLC control system; The outlet end of the anaerobic tank (100) is connected to the disinfection tank (200); The outlet end of the disinfection tank (200) is connected to the clean water tank (300); The standby tank (400) is connected to the clean water tank (300); The clean water in the clean water tank (300) flows into the fry rearing assembly through the clean water inlet pipe (500), replenishes the dissolved oxygen in the fry rearing assembly, and dilutes metabolic waste. The wastewater in the fry rearing assembly is discharged into the anaerobic tank (100) for denitrification treatment. The treated wastewater enters the disinfection tank (200), is neutralized first and then disinfected. The disinfected clean water flows into the clean water tank (300) for aeration, increases the oxygen content of the clean water, and completes the water recycling. The fry rearing assembly comprises a breeding box assembly (600), a blocking pipe assembly (700), a lifting assembly (800) and a breeding box drainage pipe (900); the movable box (820) on the top of the lifting assembly (800) is located inside the breeding box assembly (600); the fixed box (910) on the top of the breeding box drainage pipe (900) is located inside the breeding box assembly (600); the blocking pipe assembly (700) is located inside the breeding box assembly (600); and the movable box (820) is located on the top of the fixed box (910); The blocking tube assembly (700) is provided with a third through hole (701) at its center. The blocking tube assembly (700) comprises a blocking tube (710) and a connecting end plate (720). The connecting end plate (720) is provided with a fourth through hole (711) and a second groove (712). The end of the blocking tube (710) away from the connecting end plate (720) is a tapered end (713). The lifting assembly (800) further includes an electric cylinder assembly (810), the moving box (820) is located on the top of the electric cylinder assembly (810) and is fixedly connected thereto, the box body of the moving box (820) is provided with a fifth through hole (821) around it, and the bottom plate of the moving box (820) is provided with a sixth through hole (822), the aquaculture tank drainage pipe (900) further includes a U-shaped main water outlet pipe (920), the bottom plate of the fixed box (910) is provided with a seventh through hole (911) and an eighth through hole (912), and the pipe of the U-shaped main water outlet pipe (920) is provided with a tapered opening (921) corresponding to the tapered end (713).

2. The device for treating sewage by short-range denitrification in a circulating aquaculture system according to claim 1, characterized in that: The anaerobic tank (100) comprises an anaerobic tank body (110), an anaerobic tank water inlet pipe (120), a supporting layer (130), a biological filler layer (140) and an anaerobic tank drainage pipe (150). The anaerobic tank water inlet pipe (120) and the anaerobic tank drainage pipe (150) are both connected to the anaerobic tank body (110). The supporting layer (130) and the biological filler layer (140) are both located inside the anaerobic tank body (110). The biological filler layer (140) is located on the top of the supporting layer (130). A first water pump (151) is provided on the anaerobic tank drainage pipe (150). A first stop valve (201) is provided on the outlet pipe of the disinfection tank (200).

3. The device for treating sewage by short-range denitrification in a circulating aquaculture system according to claim 2, characterized in that: The clean water tank (300) comprises a clean water tank body (310), a first liquid level sensor (320), a water supply pipe (330), a bypass pipe (340) and a clean water tank drainage pipe (350), wherein the first liquid level sensor (320) is located on the front of the clean water tank body (310), the water supply pipe (330) and the clean water tank drainage pipe (350) are both connected to the clean water tank body (310), the bypass pipe (340) is located at the bottom of the clean water tank body (310) and is connected thereto, and the water supply pipe (330) is connected to the bypass pipe (340). A first solenoid valve (331) is provided, a second solenoid valve (341) is provided on the bypass pipe (340), a second stop valve (351) is provided on the clean water tank drainage pipe (350), the standby tank (400) comprises a standby tank body (410), a second liquid level sensor (420) and a standby tank drainage pipe (430), the second liquid level sensor (420) is located on the front of the standby tank body (410), and a second water pump (431) and a standby tank one-way valve (432) are provided on the standby tank drainage pipe (430).

4. The device for treating sewage by short-range denitrification in a circulating aquaculture system according to claim 3, characterized in that: The clean water inlet pipe (500) comprises a U-shaped main water inlet pipe (510), a first branch water inlet pipe (520), a second branch water inlet pipe (530), a third branch water inlet pipe (540) and a fourth branch water inlet pipe (550). The first branch water inlet pipe (520), the second branch water inlet pipe (530), the third branch water inlet pipe (540) and the fourth branch water inlet pipe (550) are all connected to the U-shaped main water inlet pipe (510). The first branch water inlet pipe (520) is provided with a third stop valve (521), the second branch water inlet pipe (530) is provided with a fourth stop valve (531), the third branch water inlet pipe (540) is provided with a fifth stop valve (541), and the fourth branch water inlet pipe (550) is provided with a sixth stop valve (551).

5. The device for treating sewage by short-range denitrification in a circulating aquaculture system according to claim 4, characterized in that: The breeding box assembly (600) comprises a breeding box shell (610), a partition plate (620) and a card plate assembly (630), wherein the partition plate (620) is located inside the breeding box shell (610), a first through hole (611) and a second through hole (612) are provided on the bottom plate of the breeding box shell (610), a partition opening (621) is provided on the partition plate (620), and three sides of the partition opening (621) are provided with first grooves (622), and the card plate assembly (630) is engaged in the partition opening (621), and the card plate assembly (630) comprises a pull-out plate (631) and a handle (633), wherein the handle (633) is located on the top of the pull-out plate (631) and is fixedly connected thereto; the partition plate (620), the movable box (820) and the breeding box shell (610) divide the fry breeding assembly into four areas A, B, C and D.

6. The device for treating sewage by short-range denitrification in a circulating aquaculture system according to claim 5, characterized in that: The flow rate V1 of water passing through a single branch water inlet pipe of the clean water inlet pipe (500), the discharge flow rate V2 of water passing only through the fourth through holes (711) of the two blocking pipe assemblies (700), and the discharge flow rate V3 of water passing simultaneously through the fourth through holes (711) and the third through holes (701) of the two blocking pipe assemblies (700) have the following relationship: V2 < V1 < V3.

7. The method for using the device for treating sewage by short-range denitrification in a circulating aquaculture system according to claim 6, characterized in that: The method of use includes a sturgeon transfer method S1, a water circulation method S2, and a method of maintaining the water level in a clear water tank S3; The sturgeon transfer method S1 includes the following steps: S11, putting clean water into the four areas A, B, C, and D of the fry rearing component, at which point the clean water cannot flow out through the fourth through hole (711), and placing sturgeons to be reared into the D area, C area, and B area of ​​the fry rearing component in sequence at preset time intervals; S12, placing feed in the area where the sturgeons are present, wherein the undigested food residues and sturgeon feces will sink to the bottom of the mobile box (820) in the corresponding area; S13, after a preset time, the third stop valve (521) above the A area of ​​the fry rearing assembly is opened and the sixth stop valve (551) above the D area is closed, and the electric cylinder assembly (810) below the D area of ​​the fry rearing assembly is lifted to the point where the movable box (820) of the area abuts against the connecting end plate (720), and the water level in the D area drops and is discharged through the third through hole (701), with a portion of the water directly entering the anaerobic tank (100) through the drainage pipe (900) of the breeding tank, and a portion of the water falling into the area between the movable box (820) and the fixed box (910) through the fourth through hole (711). When the water level in the D area drops to a preset value, the card plate assembly (630) between the D area and the A area is lifted, and the sturgeons and a small amount of water enter the A area; S14, resetting the card plate assembly (630) between the D area and the A area, and pumping the food residue and sturgeon feces in the mobile box (820) into a designated location for composting by using a mud pump; S15, continue to lift the electric cylinder assembly (810) below the D area, so that the blocking pipe assembly (700) is completely separated from the drainage pipe (900) of the aquaculture tank, and the water between the movable box (820) and the fixed box (910) enters the anaerobic tank (100) through the drainage pipe (900) of the aquaculture tank; S16, resetting the electric cylinder assembly (810) in the D region, and injecting clean water into the D region, so that the clean water cannot flow out through the fourth through hole (711); S17, sequentially moving the sturgeons in area C to area D and cleaning area C, moving the sturgeons in area B to area C and cleaning area B, and moving the sturgeons in area A to area B and cleaning area A at preset time intervals; The water recycling method S2 comprises the following steps: S21, the wastewater in the anaerobic tank (100) is subjected to denitrification treatment, further purified by the biological filler layer (140), and then pumped into the disinfection tank (200); S22, the water in the disinfection tank (200) is first neutralized and then disinfected, and the clean water after disinfection flows into the clean water tank (300); S23, aerating the water in the clean water tank (300) to increase the oxygen content of the clean water and provide a water source for the fry rearing assembly; The water level in the clear water tank (300) is automatically controlled by a liquid level sensor and a PLC control system; The method S3 for maintaining the water level in the clear water tank comprises the following steps: S31, when the water level in the clear water tank (300) is higher than the high value set by the first liquid level sensor (320), the first liquid level sensor (320) feeds back a signal to the PLC control system, and the second solenoid valve (341) is opened, and the clear water in the clear water tank (300) flows into the standby tank (400); when the water level in the clear water tank (300) drops and is lower than the high value set by the first liquid level sensor (320), the second solenoid valve (341) is closed; S32, when the water level in the clear water tank (300) is lower than the low value set by the first liquid level sensor (320), the first liquid level sensor (320) feeds back a signal to the PLC control system, and at this time the liquid level of the second liquid level sensor (420) is judged; S321, if the liquid level in the standby tank (400) is higher than the low value set by the second liquid level sensor (420), the second water pump (431) is started to pump the clean water in the standby tank (400) into the clean water tank (300); when the water level in the clean water tank (300) rises and is higher than the low value set by the first liquid level sensor (320), the second water pump (431) is turned off; S322, if the liquid level in the standby tank (400) is lower than the low value set by the second liquid level sensor (420), the first solenoid valve (331) is opened, and water is replenished into the clean water tank (300) through the water replenishment pipe (330). When the water level in the clean water tank (300) rises and is higher than the low value set by the first liquid level sensor (320), the first solenoid valve (331) is closed.

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