Biological denitrification device and method for breeding tail water

Abstract

The invention relates to the technical field of sewage treatment, and discloses an aquaculture tail water biological denitrification device and method.The aquaculture tail water biological denitrification device comprises a tank body and a ring body connected with the tank body, a filler assembly is arranged on the ring body, a lifting assembly is arranged on the tank body, an adjusting assembly is arranged on the lifting assembly, and the adjusting assembly comprises a second guide rail arranged on the lifting assembly; the second sliding block is connected to the second guide rail in a sliding mode, a submersible stirrer is arranged on the second sliding block, the second sliding block slides along the second guide rail, and after the second sliding block is aligned with one set of filler in the filler assembly, the second sliding block is lifted out of the tank body through the lifting assembly; dissolved oxygen in tail water can be effectively reduced in the mixing area, and good conditions are created for follow-up reaction; in the reaction zone, the tail water and the denitrifying sulfur autotrophic particle filler can be fully contacted and reacted, and nitrite is efficiently converted into nitrogen; the settling zone can realize solid-liquid separation, so that the treated water is clearer, and the biological nitrogen removal effect and efficiency of the culture tail water are greatly improved.

Description

Technical Field

[0001] This invention relates to the technical field of wastewater treatment, specifically to a biological denitrification device and method for aquaculture wastewater. Background Technology

[0002] Biological denitrification devices for aquaculture wastewater are a core component of aquaculture wastewater treatment. Their purpose is to efficiently remove harmful ammonia nitrogen and nitrite pollutants from uneaten feed, feces, and other waste, thereby preventing eutrophication. The core principle of this device is based on the metabolic activities of specific microorganisms (mainly nitrifying and denitrifying bacteria): nitrifying bacteria gradually oxidize ammonia nitrogen to nitrate in an aerobic environment, while denitrifying bacteria, in an anaerobic / hypoxic environment, utilize organic matter to ultimately reduce nitrate to harmless nitrogen gas, which is then released.

[0003] Biological denitrification devices for aquaculture wastewater (such as sulfur autotrophic denitrification filters) efficiently utilize microorganisms (nitrifying / denitrifying bacteria) to convert ammonia nitrogen and nitrite into nitrogen gas, representing a core technology for achieving green aquaculture. However, in practical applications, especially with sulfur autotrophic denitrification filters, there are significant shortcomings: after air or water flushing, the actual loss of sulfur autotrophic filter media far exceeds the manufacturer's claimed annual loss of <10%, often exceeding 40%. Simultaneously, dissolved oxygen levels at the downstream end of the aquaculture wastewater often exceed 4 mg / L, and this high dissolved oxygen environment accelerates the oxidation and consumption of sulfur media, leading to common problems such as media breakage and a sharp increase in loss rates during the mid-term operation. This not only significantly increases the need for media replenishment. Summary of the Invention

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a biological denitrification device and method for aquaculture wastewater. This significantly reduces the loss rate of sulfur-autotrophic filter media, effectively solves the problem of filter media breakage and a sharp increase in loss rate under high dissolved oxygen conditions, reduces filter media replenishment costs, and improves the stability and economy of the aquaculture wastewater biological denitrification device. It also solves the problem of accelerated oxidation and consumption of sulfur-containing filter media in high dissolved oxygen environments, leading to widespread filter media breakage and a sharp increase in loss rate during the mid-term operation.

[0005] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: a biological denitrification device for aquaculture wastewater, comprising a tank, an annular body connected to the tank, a packing assembly disposed on the annular body, a lifting assembly disposed on the tank, and an adjusting assembly disposed on the lifting assembly. The adjusting assembly includes: a second guide rail disposed on the lifting assembly; and a second slider slidably connected to the second guide rail, on which a submersible mixer is disposed. The second slider slides along the second guide rail, and after aligning with a set of packing material in the packing assembly, it is lifted out of the tank by the lifting assembly.

[0006] Furthermore, the packing assembly includes: a second rod body, which is disposed at the top of the ring body, and a first rod body is fixed to the bottom of the second rod body; a third rod body, which is disposed on the second rod body; and a packing ball, which is connected to the third rod body by a rope. The third rod body has a hollow structure and contains denitrifying sulfur autotrophic particles inside.

[0007] Furthermore, the lifting assembly includes: a column, which is disposed inside the tank; a support plate, which is fixed to the outer wall of the tank, and a winder is provided on the top of the support plate, on which a rope is wound, and one end of the rope is connected to the second slider.

[0008] Furthermore, a driving component is provided on the column, which is used to drive the position of the second slider on the second guide rail, so that the second slider can connect with different groups of packing.

[0009] Furthermore, the driving assembly includes: a guide rail, which is fixed to one side of the column; a motor, which is fixed to one side of the guide rail, and the output shaft of the motor is fixed with a screw, which is rotatably connected to the guide rail. A slider is threadedly connected to the outer side wall of the screw, and the slider is slidably connected to the guide rail. The rope passes through the slider.

[0010] Furthermore, a pressure sensor is provided on the second slider.

[0011] Furthermore, a buffer section is provided between the ring body and the second rod body, and a transmission component is provided inside the tank body. After the submersible mixer is connected to the transmission component, its rotational motion is converted into linear motion, thereby driving the transmission mechanism to move the first rod body up and down, causing the biofilm on the multiple packing balls to fall off.

[0012] Furthermore, the buffer section is a shock absorber.

[0013] Furthermore, the transmission mechanism includes: a support frame fixed inside the tank; a shaft rotatably connected to the support frame; an eccentric wheel fixed to the outer wall of the shaft; a rod four fixed to the bottom of the rod one; a gear two fixed to one end of the shaft; and a gear one meshing with the gear two fixed to the impeller end of the submersible mixer.

[0014] A method for biological nitrogen removal from aquaculture wastewater includes the following steps: The wastewater is introduced into a mixing zone at the bottom of the tank for pretreatment to reduce dissolved oxygen in the wastewater. The effluent passes through the sulfur autotrophic denitrification zone, where it reacts with the denitrifying sulfur autotrophic granular packing material, converting the nitrite in the effluent into nitrogen gas. The wastewater after the reaction passes through a sedimentation zone to achieve solid-liquid separation.

[0015] (III) Beneficial Effects Compared with the prior art, the present invention provides a biological denitrification device and method for aquaculture wastewater, which has the following beneficial effects: 1. This biological denitrification device for aquaculture wastewater divides the tank into three zones: a mixing zone, a reaction zone, and a sedimentation zone. This makes the function of each zone more clearly defined and independent, enabling targeted treatment of aquaculture wastewater at different stages. The mixing zone effectively reduces dissolved oxygen in the wastewater, creating favorable conditions for subsequent reactions. The reaction zone allows the wastewater to fully contact and react with the denitrifying autotrophic granular packing material, efficiently converting nitrite into nitrogen. The sedimentation zone achieves solid-liquid separation, resulting in clearer water and significantly improving the effectiveness and efficiency of biological denitrification of aquaculture wastewater.

[0016] 2. This aquaculture wastewater biological denitrification device divides the packing material into multiple packing groups by setting up multiple rods (or "three-section rods"). After a certain operating cycle, the rods (or "three-section rods") can be directly replaced, allowing the removal of some worn-out packing material. This not only facilitates the maintenance and replacement of the packing material but also ensures that the packing material in the reaction zone maintains good reactivity. When some packing material becomes worn or ineffective due to prolonged use, it is not necessary to remove the entire packing material from the reaction zone. Only the corresponding rods (or "three-section rods") and their corresponding packing groups need to be replaced to quickly restore the normal operation of the reaction zone, thereby significantly reducing maintenance costs.

[0017] 3. When the aquaculture wastewater biological denitrification device needs to replace worn-out packing material, the submersible mixer's lifting assembly can be used to raise the packing material on rod three, making the replacement process more convenient and efficient, eliminating the need for additional large hoisting equipment or complicated operating procedures. Operators only need to operate the lifting assembly to easily lift the worn-out packing material above the water surface for quick replacement.

[0018] 4. In this biological denitrification device for aquaculture wastewater, the operator can control the drive component to change the position of slider two, aligning it with different rods three, and thus with different packing groups. Then, by controlling the lifting component, the packing group that needs to be replaced can be raised for replacement. This makes packing replacement more targeted, further improving replacement efficiency, while also reducing the impact on other normal packing groups in the reaction zone.

[0019] 5. After a period of use, a biofilm will form on the outer wall of the packing balls in this aquaculture wastewater biological denitrification device. At this time, the user can connect the submersible mixer to the transmission mechanism. When the submersible mixer is running, its rotational force is transmitted to the transmission mechanism, which converts the rotational motion into linear motion, causing the entire packing assembly to move up and down, thereby shaking off the biofilm on the packing and ensuring that the packing particles inside the packing balls work properly. This process not only effectively cleans the packing and avoids packing blockage or performance degradation caused by excessive biofilm accumulation, but also significantly reduces maintenance workload and downtime. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of the present invention. Figure 2 ; Figure 3 This is a partial cross-sectional view of the present invention; Figure 4 This is a schematic diagram of the connection between the adjustment component and the vibration component in this invention. Figure 1 ; Figure 5 This is a schematic diagram of the connection between the adjustment component and the vibration component in this invention. Figure 2 ; Figure 6 For the present invention Figure 4 A magnified structural diagram at point A in the diagram.

[0021] In the picture: 100. Tank body; 110. pH sensor; 120. Overflow trough; 130. Ring body; 200. Lifting assembly; 210. Column; 220. Support plate; 230. Winder; 240. Rope; 300. Adjustment component; 310. Guide rail one; 320. Motor; 330. Screw; 340. Slider one; 350. Guide rail two; 360. Slider two; 370. Pressure sensor; 400. Packing assembly; 410. Packing ball; 420. Rod body one; 430. Rod body two; 440. Rod body three; 500. Submersible mixer; 510. Gear 1; 610. Support frame; 620. Eccentric wheel; 630. Rod four; 640. Buffer part; 650. Shaft; 660. Gear two. 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] Biological denitrification devices for aquaculture wastewater are a core component of aquaculture wastewater treatment. Their purpose is to efficiently remove harmful ammonia nitrogen and nitrite pollutants from uneaten feed, feces, and other waste, thereby preventing eutrophication. The core principle of this device is based on the metabolic activities of specific microorganisms (mainly nitrifying and denitrifying bacteria): nitrifying bacteria gradually oxidize ammonia nitrogen to nitrate in an aerobic environment, while denitrifying bacteria, in an anaerobic / hypoxic environment, utilize organic matter to ultimately reduce nitrate to harmless nitrogen gas, which is then released.

[0024] Biological denitrification devices for aquaculture wastewater (such as sulfur autotrophic denitrification filters) can efficiently utilize microorganisms (nitrifying / denitrifying bacteria) to convert ammonia nitrogen and nitrite into nitrogen gas, which is a core technology for achieving green aquaculture. However, in practical applications, especially in the form of sulfur autotrophic denitrification filters, there are obvious shortcomings: after air or water flushing, the actual loss of sulfur autotrophic filter media far exceeds the manufacturer's claimed annual loss of <10%, often exceeding 40%; at the same time, the dissolved oxygen at the downstream end of the aquaculture wastewater is often higher than 4 mg / L, and the high dissolved oxygen environment accelerates the oxidation and consumption of sulfur packing, resulting in problems such as filter media breakage and a sharp increase in loss rate during the middle of operation. This not only greatly increases the need for filter media replenishment. This application proposes to divide the packing into multiple packing groups by setting multiple rods. After a certain period of operation, the rods can be directly replaced, thereby removing some of the worn-out packing. This not only facilitates the maintenance and replacement of the packing, but also ensures that the packing in the reaction zone always maintains good reactivity. When some of the packing material is worn out or fails due to prolonged use, it is not necessary to remove the entire packing material from the reaction zone. Instead, the corresponding rod and the packing assembly on it need to be replaced in a targeted manner to quickly restore the normal operation of the reaction zone, thereby significantly reducing maintenance costs.

[0025] As attached Figure 1-6 As shown, this embodiment provides a biological denitrification device for aquaculture wastewater, including a tank 100, an annular body 130 connected to the tank 100, an inlet pipe and an outlet pipe on the tank 100, a pH sensor 110 on the tank 100, an overflow trough 120 fixed to the inner wall of the tank 100, and a packing assembly 400 on the annular body 130. The interior of the tank 100 is divided into three areas: a mixing zone at the bottom, equipped with a submersible mixer 500; a reaction zone in the middle; and a sedimentation zone at the top.

[0026] A lifting assembly 200 is installed on the tank body 100, and an adjusting assembly 300 is installed on the lifting assembly 200. The adjusting assembly 300 includes: a second guide rail 350, which is installed on the lifting assembly 200; and a second slider 360, which is slidably connected to the second guide rail 350. A submersible mixer 500 is installed on the second slider 360. The second slider 360 slides along the second guide rail 350. After aligning with a set of packing material in the packing assembly 400, it is lifted out of the tank body 100 by the lifting assembly 200. The power of the submersible mixer 500 is configured according to the volume of the influent mixing layer × 5W. It achieves thorough mixing of mud and water through mechanical agitation, utilizing the naturally present COD and NO3 in the influent to undergo heterotrophic denitrification reaction, while consuming dissolved oxygen in the water. The packing assembly 400 uses denitrifying sulfur autotrophic granular packing material to convert nitrite in the effluent into nitrogen gas. When the packing particles undergo natural loss due to microbial action, the broken particles can fall into the influent mixing zone with the water flow and continue to participate in the sulfur autotrophic denitrification reaction there. Solid-liquid separation in the clear water zone is mainly achieved through sedimentation. The overflow trough 120 ensures a stable discharge of clear water.

[0027] Specifically, the pH of the reaction system needs to be maintained between 7.8 and 8.0. When the monitored value is lower than 7.8, sodium hydroxide is added for adjustment. The denitrification load capacity of the device is designed to be 0.4 kg NO3- / m³·d. Through stratified reaction and parameter control, the source control of interference factors such as dissolved oxygen and COD is achieved to ensure the continuous and stable denitrification efficiency.

[0028] As attached Figure 3-6 As shown, the packing assembly 400 includes: rod 2 430, rod 3 440, and packing ball 410. Rod 2 430 is located at the top of the ring 130. Two rods 2 430 are provided and arranged in parallel. Rod 1 420 is fixed to the bottom of rod 2 430; rod 1 420 is used to connect the two rods 2 430. Rod 3 440 is located on rod 2 430; multiple grooves are formed on rod 2 430, and rod 3 440 can be engaged into these grooves. The packing ball 410 is connected to rod 3 440 by a rope. Rod 3 440 has a hollow structure (not shown in the attached figure) and contains denitrifying sulfur autotrophic particles inside. The rope passes through multiple packing balls 410 and is knotted after passing through one ball to ensure the position of the packing ball 410. The connection method between the packing ball 410 and the rope is prior art and will not be described further here.

[0029] Specifically, the denitrifying sulfur autotrophic granular packing material is made by mixing sulfur, calcium hydroxide, shell powder, and nano-sodium carbonate in a ratio of 9.5:0.3:0.2:0.1. Sulfur provides the necessary sulfur element for sulfur autotrophic denitrification, calcium hydroxide serves as an alkalinity supplement to maintain the stability of the reaction system, shell powder increases the structural hardness of the packing material to reduce breakage, and nano-sodium carbonate constructs a hydrophilic contact surface to promote microbial attachment and colonization. Furthermore, this packing material is a reinstallable type.

[0030] As attached Figure 1-6 As shown, the lifting assembly 200 includes: a column 210 and a support plate 220. The column 210 is disposed inside the tank body 100; the support plate 220 is fixed to the outer wall of the tank body 100, and a winder 230 is disposed on the top of the support plate 220. A rope 240 is wound on the winder 230, and one end of the rope 240 is connected to the slider 360.

[0031] Specifically, the winding device 230 mainly consists of a support arm and a winch. The support arm supports the winch. The winch works as follows: a power source (such as an electric motor, hydraulic motor, or manual power) provides initial energy and generates rotational motion; this motion is transmitted and converted through a transmission system (mainly including a reducer and a clutch). The reducer lowers the high speed and significantly increases the torque to meet traction requirements, while the clutch controls the on / off state of power transmission. The increased torque drives the drum to rotate, generating strong tension by winding or releasing the wire rope (or chain, rope) on it, thereby achieving the lifting, traction, or lowering of heavy objects controlled by the load's own weight / reverse traction force. This is existing technology and will not be elaborated further here. A through hole is provided on the slider 2 360, through which the entire submersible mixer 500 can pass. When overhauling the submersible mixer 500, the retractor 230 is controlled to wind up the rope 240, which in turn pulls the slider 360 upward, raising the submersible mixer 500 to the outside of the tank 100. This allows operators to perform comprehensive overhaul and maintenance without needing to enter the tank, greatly improving the safety and convenience of the maintenance work. The rope 240 can be a steel wire rope.

[0032] As attached Figure 3-6 As shown, a drive assembly is provided on the column 210. The drive assembly is used to drive the slider 360 to position on the guide rail 350, so that the slider 360 can dock with different groups of packing. The drive assembly includes: a guide rail 310 and a motor 320. The guide rail 310 is fixed to one side of the column 210; the motor 320 is fixed to one side of the guide rail 310. The output shaft of the motor 320 is fixed with a screw 330, which is rotatably connected to the guide rail 310. A slider 340 is threadedly connected to the outer wall of the screw 330, and the slider 340 is slidably connected to the guide rail 310. A rope 240 passes through the slider 340.

[0033] Specifically, the drive assembly changes the Z-axis direction of the rope 240 (the long side of rod 430). The motor 320 drives the screw 330 to rotate. The rotation of the screw 330 causes the slider 340, connected to its thread (not shown in the attached diagram), to slide on the guide rail 310. This sliding of the slider 340, in turn, moves the rope 240 in the Z-axis direction. Since one end of the rope 240 is connected to the slider 360, the movement of the rope 240 causes the slider 360 to slide on the guide rail 350, achieving precise control of the slider 360's position. The guide rail 350 limits the swing of the rope 240 to some extent. Thus, the operator can move the slider 360 to the position corresponding to a specific set of filler (corresponding to rod 440) as needed for subsequent filler replacement or maintenance.

[0034] As attached Figure 6 As shown, a pressure sensor 370 is installed on slider 2 360. When rod 3 440 is on both sliders 2 360, it is lifted by rope 240 until it separates from rod 2 430. The pressure sensor 370 can measure the weight of the packing on rod 3 440, allowing the operator to determine the degree of wear of the packing. When the pressure reading is lower than a preset threshold, the packing needs to be replaced to avoid a decrease in denitrification efficiency due to excessive packing wear. Compared to traditional manual visual inspection or periodic replacement, this dynamic management strategy based on gravity monitoring significantly improves the accuracy and economy of maintenance, further reducing operating costs. When multiple packing groups are subjected to gravity testing, the entire tank 100 is empty, reducing the error caused by water affecting the pressure sensor 370 reading and ensuring the accuracy and reliability of the measurement data.

[0035] As attached Figure 3-6 As shown, a buffer section 640 is provided between the ring body 130 and the second rod body 430. A transmission assembly is installed inside the tank body 100. After the submersible mixer 500 is connected to the transmission assembly, its rotational motion is converted into linear motion, which in turn drives the transmission mechanism to move the first rod body 420 up and down, causing the biofilm on the multiple packing balls 410 to detach. The buffer section 640 is a shock absorber, mainly composed of shock-absorbing pads. It absorbs impact energy through the deformation of elastic materials (such as rubber and polyurethane), while relying on a sealing structure or hydrophobic materials to isolate moisture, ensuring that the up-and-down shaking amplitude of the entire packing assembly 400 is uniform and stable, avoiding damage to the packing balls 410 or uneven biofilm detachment due to excessive local impact. Furthermore, the shock absorber extends the service life of the packing assembly 400.

[0036] Specifically, the rotational motion of the submersible mixer 500 is converted into the linear up-and-down motion of the rod 420 via a transmission component. Utilizing the principle of mechanical energy conversion, this enables the periodic and efficient cleaning of the biofilm on the packing balls 410. The timely removal of the biofilm not only promotes its renewal and maintains its high denitrification activity but also prevents clogging caused by excessive biofilm thickness, ensuring the continuous and stable operation of the aquaculture wastewater treatment system. Furthermore, it reduces the frequency and difficulty of manual cleaning, lowers maintenance costs, and improves overall treatment efficiency.

[0037] As attached Figure 3-6 As shown, the transmission mechanism includes: a support frame 610, a rod 630, a shaft 650, and an eccentric wheel 620. The support frame 610 is fixed inside the tank 100; the shaft 650 is rotatably connected to the support frame 610; the eccentric wheel 620 is fixed to the outer wall of the shaft 650; the rod 630 is fixed to the bottom of the rod 620; a gear 660 is fixed to one end of the shaft 650; and a gear 510 meshing with the gear 660 is fixed to the impeller end of the submersible mixer 500.

[0038] Specifically, when the biofilm needs to be cleaned after the equipment has been used for a period of time, the submersible mixer 500 is lowered to the point of docking with the transmission mechanism via the lifting component 200. The submersible mixer 500 is then started, and the shaft 650 and eccentric wheel 620 are driven to rotate through the meshing transmission of gear 1 510 and gear 2 660. The rotation of eccentric wheel 620 further drives rod 430 and rod 1 420 to move linearly up and down, thereby shaking off and cleaning the biofilm on the packing ball 410.

[0039] As attached Figure 6 As shown, in this embodiment, the pH of the reaction system needs to be maintained between 7.8 and 8.0. When the monitored value is lower than 7.8, sodium hydroxide is added for adjustment. A flexible tube is installed on the second slider 360, and a sodium hydroxide flow channel is opened on the second slider 360. A one-way valve is installed at the outlet of the flow channel. When sodium hydroxide needs to be added, the operator only needs to inject it into the flexible tube and discharge it through the flow channel. At this time, the stirring action of the submersible mixer 500 can make the sodium hydroxide quickly and evenly dispersed in the reaction system, thereby quickly and effectively adjusting the pH value of the reaction system and ensuring that the reaction system is always maintained within a suitable range of 7.8-8.0, providing a stable environment for the metabolic activities of microorganisms and ensuring the efficient progress of the denitrification reaction.

[0040] A method for biological nitrogen removal from aquaculture wastewater includes the following steps: The effluent is introduced into the mixing zone at the bottom of the tank 100 for pretreatment to reduce the dissolved oxygen in the effluent; The effluent passes through the sulfur autotrophic denitrification zone, where it reacts with the denitrifying sulfur autotrophic granular packing material, converting the nitrite in the effluent into nitrogen gas. The wastewater after the reaction passes through a sedimentation zone to achieve solid-liquid separation.

[0041] Application examples: Case 1: Freshwater Fishpond Wastewater Treatment Project A freshwater fishpond discharges approximately 500 m³ of wastewater daily, with a COD of about 80 mg / L, ammonia nitrogen concentration of 15-20 mg / L, and an average dissolved oxygen of 4.5 mg / L. Using a traditional sulfur-autotrophic denitrification filter, the monthly filter media replenishment is approximately 1.2 tons. After 6 months of operation, the filter media is severely damaged and needs to be completely replaced, with total material costs exceeding 80,000 yuan.

[0042] After using the device of this invention: The influent mixing zone reduces dissolved oxygen to below 1.2 mg / L through heterotrophic denitrification, thereby reducing the oxidation loss of the packing material. Sulfur-based slow-release packing requires less annual replenishment, and the lost particles continue to play a role in the influent mixing zone; After 12 months of operation, there is still no need to replace the entire packing material, the cumulative material cost is reduced, the denitrification efficiency is stably maintained at over 85%, and the effluent meets the discharge standards.

[0043] Case Study 2: Factory-Scale Shrimp Pond Circulating Water Treatment System A certain factory-scale shrimp pond uses a recirculating aquaculture system with a daily circulating water volume of 2000 m³. The nitrate concentration in the effluent is 25 mg / L, and the dissolved oxygen fluctuates between 4 and 6 mg / L. Due to excessively high dissolved oxygen levels, the original treatment system experienced a monthly loss rate of 15% for the sulfur-based autotrophic packing material and frequently produced an unpleasant hydrogen sulfide odor.

[0044] After using this device: Submersible mixers ensure sufficient reaction in the influent mixing zone, increasing COD utilization by 40% and keeping dissolved oxygen stably controlled below 1 mg / L. Due to the optimization of alkalinity and hardness, sulfur-based fillers have improved resistance to breakage, and the monthly loss rate has been reduced to below 3%. The pH online monitoring and automatic alkali adjustment system completely avoids the generation of hydrogen sulfide. There have been no complaints about odors after 6 months of operation. The cost of replenishing the packing material has been reduced by 70% compared to before, and the recycling rate of circulating water has increased from 60% to 85%.

[0045] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for biological denitrification of aquaculture tail water, comprising a tank body (100), a ring body (130) connected with the tank body (100), characterized in that, The ring body (130) is provided with a filler assembly (400), the tank body (100) is provided with a lifting assembly (200), the lifting assembly (200) is provided with an adjusting assembly (300), the adjusting assembly (300) comprises: The guide rail two (350) is arranged on the lifting assembly (200); The slider two (360) is slidingly connected to the guide rail two (350), the slider two (360) is provided with a diving mixer (500), the slider two (360) slides along the guide rail two (350), and after being aligned with a group of fillers in the filler assembly (400), it is lifted out of the tank body (100) by the lifting assembly (200).

2. The device and method for denitrification of aquaculture tail water according to claim 1, characterized in that: The filler assembly (400) comprises: The rod body two (430) is arranged at the top of the ring body (130), and the bottom of the rod body two (430) is fixed with a rod body one (420); The rod body three (440) is arranged on the rod body two (430); The filler ball (410) is connected to the rod body three (440) by a rope body, the rod body three (440) is a hollow structure, and the inside is provided with a denitrification sulfur autotrophic particle.

3. The device for denitrification of aquaculture tail water according to claim 2, characterized in that: The lifting assembly (200) comprises: The stand column (210) is arranged in the inside of the tank body (100); The support plate (220) is fixed to the outer side wall of the tank body (100), and the top of the support plate (220) is provided with a winder (230), the winder (230) is wound with a rope body (240), and one end of the rope body (240) is connected with the slider two (360).

4. The device for denitrification of aquaculture tail water according to claim 3, characterized in that: The stand column (210) is provided with a driving assembly, the driving assembly is used for driving the position of the slider two (360) on the guide rail two (350), so that the slider two (360) is connected with different groups of fillers.

5. The device for denitrification of aquaculture tail water according to claim 4, characterized in that: The driving assembly comprises: The guide rail one (310) is fixed to one side of the stand column (210); The motor (320) is fixed to one side of the guide rail one (310), the output shaft of the motor (320) is fixed with a screw rod (330), the screw rod (330) is rotatably connected with the guide rail one (310), the outer side wall of the screw rod (330) is threadedly connected with a slider one (340), the slider one (340) is slidingly connected with the guide rail one (310), and the rope body (240) penetrates through the slider one (340).

6. The device for denitrification of tail water from aquaculture according to any of claims 2-5, characterized in that: The slider two (360) is provided with a pressure sensor (370).

7. The device for denitrification of aquaculture tail water according to claim 6, characterized in that: The buffer part (640) is arranged between the ring body (130) and the rod body two (430), the inside of the tank body (100) is provided with a transmission assembly, after the submersible mixer (500) and the transmission assembly complete butt joint, the rotary motion is converted into linear motion, and then drives the transmission mechanism to drive the rod body one (420) to move up and down, so as to make the biofilm on the plurality of filler balls (410) shake off.

8. The device for denitrification of aquaculture tail water according to claim 7, characterized in that: The buffer part (640) is a shock absorber.

9. The device for denitrification of aquaculture tail water according to claim 7, characterized in that: The transmission mechanism comprises: A support frame (610) is fixed to the inside of the tank body (100); An axle body (650) is rotatably connected to the support frame (610); An eccentric wheel (620) is fixed to the outer side wall of the axle body (650); A rod body four (630) is fixed to the bottom of the rod body one (420), one end of the axle body (650) is fixed with a gear two (660), and the impeller end of the submersible mixer (500) is fixed with a gear one (510) matched with the gear two (660).

10. The method of claim 9, wherein the device is used for biological denitrification of aquaculture tail water. The method comprises the following steps: The tail water is introduced into the mixing area at the bottom of the tank body (100) for pretreatment, so as to reduce the dissolved oxygen in the tail water; The tail water passes through the sulfur autotrophic denitrification area and reacts with the denitrifying sulfur autotrophic granular filler, so as to convert nitrite in the tail water into nitrogen gas; The reacted tail water passes through the precipitation of the clear water area to realize solid-liquid separation.

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