Biochemical denitrification reactor
By synergistically implementing short-cut nitrification-denitrification and anaerobic ammonia oxidation in a biochemical denitrification reactor, the problems of low efficiency and high energy consumption in the treatment of high-concentration nitrogen-containing wastewater by traditional nitrification-denitrification processes have been solved, achieving efficient and economical denitrification.
Patent Information
- Application Number
- CN202423033730.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-11-14
- Estimated Expiration
- 2034-12-10
AI Technical Summary
Traditional nitrification-denitrification processes are inefficient, energy-intensive, and require large carbon sources when treating high-concentration nitrogen-containing organic wastewater, and are prone to causing secondary pollution. Short-cut nitrification-denitrification technology has unsatisfactory denitrification effects in the treatment of high-concentration nitrogen-containing wastewater, while anaerobic ammonia oxidation technology has problems such as difficulty in enriching functional bacteria and harsh reaction conditions.
A biochemical denitrification reactor is designed to achieve synergistic short-cut nitrification-denitrification and anaerobic ammonia oxidation within the same reactor. By combining a liquid hydrocyclone to screen functional bacteria and recover active bacteria, the reaction conditions are optimized, and components such as a water distributor, packing material, and hydrocyclone are used to achieve multi-path denitrification.
It achieves efficient and economical deep treatment of high-concentration nitrogen-containing organic wastewater, reduces carbon source consumption and energy consumption, avoids secondary pollution, and improves denitrification efficiency.
Smart Images
Figure CN223547842U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of sewage treatment equipment, specifically a biochemical denitrification reactor. Background Technology
[0002] Currently, traditional nitrification-denitrification processes dominate the wastewater treatment field, but they have significant drawbacks, such as low treatment efficiency, high energy consumption, high carbon source requirements, and a tendency to cause secondary pollution. With the acceleration of industrialization and urbanization, the discharge of high-concentration nitrogen-containing organic wastewater is constantly increasing. How to efficiently and economically treat this type of wastewater has become an urgent problem to be solved in the field of environmental engineering.
[0003] To meet the requirements of efficient and economical treatment of high-concentration nitrogen-containing organic wastewater, short-cut nitrification-denitrification technology has emerged. This technology controls reaction conditions to keep the ammonia nitrogen oxidation process at the nitrite stage, avoiding the formation of nitrates in traditional nitrification, thereby reducing the carbon source required for subsequent denitrification and lowering treatment costs. However, simple short-cut nitrification-denitrification technology still struggles to achieve ideal nitrogen removal efficiency when treating high-concentration nitrogen-containing wastewater.
[0004] Meanwhile, the discovery of anammox technology has revolutionized wastewater nitrogen removal. Anammox bacteria can directly generate nitrogen gas from ammonia nitrogen and nitrite under anaerobic conditions, achieving complete nitrogen removal. This technology not only avoids the consumption of large amounts of alkali and carbon sources in traditional nitrification and denitrification processes, but also significantly reduces energy consumption and greenhouse gas emissions, making it a disruptive technology in wastewater treatment.
[0005] The short-cut nitrification-denitrification coupled with anaerobic ammonia oxidation (ANAO) nitrogen removal process has emerged. Corresponding short-cut nitrification-denitrification coupled with ANAO nitrogen removal equipment overcomes the difficulties in enriching functional bacteria and the harshness of reaction conditions by optimizing the structure and reaction conditions. This allows short-cut nitrification and autotrophic denitrification to proceed synergistically within the same reactor, achieving highly efficient nitrogen removal through multiple pathways. This short-cut nitrification-denitrification coupled with ANAO nitrogen removal equipment not only overcomes the shortcomings of traditional nitrification-denitrification technologies but also fully leverages the advantages of autotrophic denitrification technology, providing a novel solution for the deep treatment of high-concentration nitrogen-containing organic wastewater. Utility Model Content
[0006] The purpose of this invention is to provide a biochemical denitrification reactor. This biochemical denitrification reactor, through its design, enables simultaneous or separate short-cut nitrification-denitrification coupled with anaerobic ammonia oxidation for denitrification. Simultaneously, a liquid cyclone separator is used to screen functional bacteria and recover overflowing active bacteria, thereby achieving selective biochemical denitrification under various operating conditions.
[0007] The objective of this utility model is achieved through the following technical solution:
[0008] This utility model includes an inlet pipe, a reactor tank, a gas-liquid separator, a circulating water pump, a hydrocyclone, a high-pressure water pump, a gas-liquid mixer, and a bridging inlet pipe. A water distributor is installed at the bottom of the reactor tank, and the gas-liquid separator is located at the top of the reactor tank. The reactor tank is filled with packing material. An inlet pipe and a bridging inlet pipe are connected in parallel between the high-pressure water pump and the reactor tank. An inlet valve and a gas-liquid mixer are installed on the inlet pipe, and an inlet valve is installed on the bridging inlet pipe. The circulating water pump and the hydrocyclone are located outside the reactor tank. The hydrocyclone is connected to the reactor tank via a circulation pipeline, and the circulating water pump is installed on the circulation pipeline. A dosing port for adding nutrient agents is provided on the circulation pipeline. The reactor tank has a sampling port and a sludge inlet / outlet, and probes for monitoring different parameters are installed on it.
[0009] Wherein: there are one or more packing materials, each packing material includes a packing brush and a packing ring, the packing ring is fixed on the inner wall of the reactor tank, there are multiple packing brushes arranged circumferentially, one end of each packing brush is connected to the packing ring, and the other end of each packing brush is a free end. During the operation of the reactor, the other end of each packing brush is suspended in the water.
[0010] The packing material is located between the liquid surface at the top of the reactor tank and the center plane of the reactor tank. The packing ring is fixed by a clip embedded in the inner wall of the reactor tank. The length of the packing brush is 50% to 90% of the radius of the radial cross-section of the reactor tank. The arrangement density of the packing brush accounts for 50% to 95% of the radial cross-section area of the reactor tank. The distance between the uppermost packing material and the liquid surface at the top of the reactor tank is 800 mm to 1500 mm.
[0011] The water distributor includes coils, main pipes, inclined pipes, and risers. Multiple coils are arranged concentrically. Each coil is connected to the inlet pipe from the center by the main pipe. Multiple inclined pipes with the same inclination direction are arranged in the circumferential shear direction of each coil and are connected to the inside of the coil. Multiple risers are evenly arranged circumferentially on the upper surface of each coil. The lower end of each riser is connected to the inside of the coil, and the upper end of each riser is equipped with a float valve.
[0012] The gas-liquid separator has a gas collection pipe and a liquid discharge pipe, and both ends of the gas collection pipe are funnel-shaped; the gas-liquid separator is provided with a waste gas discharge pipe that is connected to the centralized waste gas collection pipe at the rear end.
[0013] The upper end of the gas collection pipe is located inside the gas-liquid separator, and the lower end of the gas collection pipe is located above the liquid level at the top of the reactor tank; the upper end of the liquid discharge pipe is connected to the bottom of the gas-liquid separator, and the lower end of the liquid discharge pipe is located above the liquid level at the top of the reactor tank.
[0014] The inlet of the circulating water pump is connected to the reactor tank through the circulating pipeline B, the outlet of the circulating water pump is connected to the inlet of the hydrocyclone, the outlet of the hydrocyclone is connected to the reactor tank through the circulating pipeline A, and the dosing port is set on the circulating pipeline A; the hydrocyclone is provided with a tail end outlet pipe.
[0015] The connection point between circulation pipeline B and the reactor tank is located between the top liquid level and the uppermost packing layer inside the reactor tank, while the connection point between circulation pipeline A and the reactor tank is located above the water distributor.
[0016] The probes include a pH probe, an ORP probe, a temperature probe, and a DO probe. The ORP probe and the temperature probe are located at the middle position of the upper part of the effective liquid level of the reactor tank. There are two DO probes, located at the middle position of the upper part and the middle position of the lower part of the effective liquid level of the reactor tank, respectively. The pH probe is located at the middle position of the lower part of the effective liquid level of the reactor tank, and together with the DO probe below it, they are located on the left and right sides of the cross section in the height direction of the reactor tank.
[0017] The reactor tank has a diameter-to-height ratio of 1:1 to 5 and an upward flow velocity of 1 to 6 m / h.
[0018] The advantages and positive effects of this utility model are as follows:
[0019] This invention enables short-cut nitrification, denitrification, and anaerobic ammonium oxidation to be carried out synergistically in the same reactor through the action of water distributor, packing material, and hydrocyclone. It can also achieve anaerobic ammonium oxidation denitrification process alone, achieving flexible practicality. It avoids the phenomenon of dead sludge accumulation due to incomplete biochemical reaction. It achieves the goals of reducing carbon sources, carbon emissions, and high energy consumption, providing a brand-new solution for the deep treatment of high-concentration nitrogen-containing organic wastewater. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the structure of this utility model;
[0021] Figure 2 This is a schematic diagram of the structure of the water distributor of this utility model;
[0022] Figure 3 This is a schematic diagram of the structure of the packing material of this utility model;
[0023] Wherein: 1 is the inlet pipe, 2 is the water distributor, 3 is the reaction tank, 4 is the packing, 5 is the gas-liquid separator, 6 is the circulating water pump, 7 is the hydrocyclone, 8 is the dosing port, 9 is the pH probe, 10 is the ORP (oxidation-reduction potential) probe, 11 is the temperature probe, 12 is the sampling port, 13 is the circulation pipe A, 14 is the tail end outlet pipe, 15 is the waste gas outlet pipe, 16 is the inlet high-pressure water pump, 17 is the sludge dosing / discharging port, 18 is the gas-liquid mixer, 19 is the inlet bridging pipe, 20 is the DO (dissolved oxygen) probe, 21 is the inlet valve, 22 is the gas collection pipe, 23 is the liquid discharge pipe, 24 is the inclined pipe, 25 is the riser, 26 is the coil, 27 is the packing brush, 28 is the clip, 29 is the packing ring, 30 is the main pipe, 31 is the top liquid level, and 32 is the circulation pipe B. Detailed Implementation
[0024] The present invention will now be described in further detail with reference to the accompanying drawings.
[0025] Example 1
[0026] like Figure 1 As shown, this utility model includes an inlet pipe 1, a reactor tank 3, a gas-liquid separator 5, a circulating water pump 6, a hydrocyclone 7, a high-pressure water pump 16, a gas-liquid mixer 18, and a bridging inlet pipe 19. A water distributor 2 is installed at the bottom of the reactor tank 3, and the gas-liquid separator 5 is located at the top of the reactor tank 3 to separate the gas and liquid for processing. The reactor tank 3 is internally equipped with packing 4. The high-pressure water pump 16 is connected in parallel to the reactor tank 3 via the inlet pipe 1 and the bridging inlet pipe 19. An inlet valve 21 and a gas inlet valve 22 are installed on the inlet pipe 1. The liquid mixer 18 is connected to the inlet pipe 19 and is equipped with an inlet valve 21; the circulating water pump 6 and the hydrocyclone 7 are located outside the reactor tank 3 to separate the activated sludge and the old sludge, and to circulate and enrich the target bacterial sludge. The hydrocyclone 7 is connected to the reactor tank 3 through the circulation pipeline. The circulating water pump 6 is installed on the circulation pipeline, and the circulation pipeline has an inlet 8 for adding nutrient agents; the reactor tank 3 is equipped with a sampling port 12 and a sludge feeding / discharging port 17, and is equipped with probes for monitoring different parameters.
[0027] In this embodiment, one end of the bridging inlet pipe 19 is connected between the high-pressure water pump 16 and the inlet valve 21 on the inlet pipe 1, and the other end of the bridging inlet pipe 19 is connected between the gas-liquid mixer 18 and the reactor tank 3.
[0028] The packing material 4 can be one or more, such as Figure 1 and Figure 3As shown, in this embodiment, there are three packing materials 4 arranged vertically and parallel to each other. The three packing materials 4 are located between the top liquid surface 31 and the center plane of the reactor tank 3. Each packing material 4 includes a packing brush 27 and a packing ring 29. The packing ring 29 is fixed to the inner wall of the reactor tank 3 by a clip 28 pre-embedded in the inner wall of the reactor tank 3. The number of clips 28 can be set as needed. There are multiple packing brushes 27 arranged circumferentially. One end of each packing brush 27 is respectively attached to the packing ring 29, and the other end of each packing brush 27 is a free end. During the operation of the reactor, the other end of each packing brush 27 is suspended in the water and can rise and fall with the rise and fall of the water, which plays a role in intercepting sludge and cultivating bacteria. The length of the packing brush 27 is 50% to 90% of the radial cross-sectional radius of the reactor tank 3. The arrangement density of the packing brush 27 accounts for 50% to 95% of the radial cross-sectional area of the reactor tank 3. The distance between the uppermost packing material 4 and the top liquid surface of the reactor tank 3 is 800mm to 1500mm. In this embodiment, the materials of the packing brush 27 and the packing ring 29 are both corrosion-resistant and non-toxic materials, which can be PE, PP, PVC or polyester fiber.
[0029] like Figure 1 , Figure 2 As shown, the water distributor 2 in this embodiment includes a coil 26, a main pipe 30, an inclined pipe 24, and a riser 25. The function of the coil 26 is to distribute water. Multiple coils arranged concentrically achieve uniform water distribution. The area of the coil 26 occupies 30% to 80% of the bottom area of the reactor tank 3. Each coil 26 is connected to the inlet pipe 1 from the center by the main pipe 30. The connection between the main pipe 30 and each coil 26 is at an arc of 30 to 60°. Each coil 26 has multiple inclined pipes with the same circumferential shear direction. The inclined tube 24 is used to purge the bottom of the reactor tank 3, and the uniform agitation reduces the accumulation of sludge at the bottom of the reactor tank 3. The inclined tube 24 is connected to the inside of the coil 26. Multiple risers 25 are evenly arranged circumferentially on the upper surface of each coil 26. The lower end of each riser 25 is connected to the inside of the coil 26, and the upper end of each riser 25 is equipped with a float valve. The riser 26 with its own float valve structure is existing technology. Its function is to allow water to flow upward, reduce pipe blockage, and ensure stable operation.
[0030] like Figure 1As shown, in this embodiment, the gas-liquid separator 5 is located at the top of the reactor tank 3, under a slight negative pressure. It has a gas collection pipe 22 and a liquid discharge pipe 23. Both ends of the gas collection pipe 22 are funnel-shaped. The upper end of the gas collection pipe 22 is located in the middle of the gas-liquid separator 5, penetrating its center, while the lower end is above the liquid surface 31 at the top of the reactor tank 3. There are two liquid discharge pipes 23, symmetrically located on the left and right sides of the gas collection pipe 22. The upper end of each liquid discharge pipe is connected to the bottom of the gas-liquid separator 5, and the lower end of each liquid discharge pipe 23 is above the liquid surface 31 at the top of the reactor tank 3. The top of the gas-liquid separator 5 is equipped with a waste gas discharge pipe 15, which is connected to a centralized waste gas collection pipe at the rear. When water momentarily enters the gas-liquid separator 5 through the gas collection pipe 22, the overflowing water returns to the reactor tank 3 through the liquid discharge pipe 23, achieving gas-liquid separation.
[0031] The hydrocyclone separator is powered by a circulating water pump. In this embodiment, the inlet of the circulating water pump 6 is connected to the reactor tank 3 via a circulating pipe B32, and the outlet of the circulating water pump 6 is connected to the inlet of the hydrocyclone 7. The connection point between the circulating pipe B32 and the reactor tank 3 is located between the top liquid level 31 and the uppermost packing 4 inside the reactor tank 3. The outlet of the hydrocyclone 7 is connected to the reactor tank 3 via a circulating pipe A13. The connection point between the circulating pipe A13 and the reactor tank 3 is located 500mm to 700mm above the water distributor 2. The dosing port 8 is located on the circulating pipe A13, through which nutrient agents are added into the circulating pipe B13. In this embodiment, the nutrient agent can be one or more of the following: sulfide, dipotassium hydrogen phosphate, disodium hydrogen phosphate, alkali solution, dilute acid solution, and trace elements (in this case, dipotassium hydrogen phosphate). The hydrocyclone 7 is equipped with a tail-end outlet pipe 14. The hydrocyclone 7 separates old sludge and light component bacteria, retaining surviving sludge and AnAOB bacteria, allowing activated sludge and AnAOB bacteria to circulate back into the reaction tank, while old sludge and light component bacteria are discharged into the rear end. At the same time, the circulating water pump 6 increases the upward flow velocity in the reactor tank 3, allowing the wastewater and activated sludge to fully contact and achieve a highly efficient denitrification reaction.
[0032] The diameter-to-height ratio of reactor tank 3 is 1:1 to 5, and the upward flow velocity is 1 to 6 m / h. In this embodiment, the diameter-to-height ratio of reactor tank 3 is 1:2 to 3, and the upward flow velocity is 2 to 4 m / h, thereby achieving efficient denitrification under low carbon-to-nitrogen ratio conditions and reducing operating costs.
[0033] The probes in this embodiment include a pH probe 9, an ORP probe 10, a temperature probe 11, and a DO probe 20. Each probe detects changes in water quality and adjusts the reaction environment conditions online. The ORP probe 10 and the temperature probe 11 are located at the middle of the upper part of the effective liquid level in the reactor tank 3. There are two DO probes 20, located at the middle of the upper part and the middle of the lower part of the effective liquid level in the reactor tank 3, respectively. The pH probe 9 is located at the middle of the lower part of the effective liquid level in the reactor tank 3, and together with the DO probe 20 below it, they are located on the left and right sides of the cross section in the height direction of the reactor tank 3, respectively.
[0034] In this embodiment, the sampling port 12 and the sludge feeding / discharging port 17 are both located at the bottom of the reactor tank 3. Activated sludge can be manually fed into the reactor tank 3 through the sludge feeding / discharging port 17.
[0035] The hydrocyclone 7, pH probe 9, ORP probe 10, temperature probe 11, gas-liquid mixer 18, and DO probe 20 of this utility model are all existing technologies and will not be described in detail here.
[0036] The working principle of this embodiment is as follows:
[0037] The gas-liquid mixer 18 selects the desired reaction system by controlling the air volume. The inlet valve 21 on the inlet pipe 1 is open, and the inlet valve 21 on the bridging inlet pipe 19 is closed. The water entering the reactor tank 3 is brought in by the high-pressure water pump 16 through the gas-liquid mixer 18 and the set amount of air into the water distributor 2, making the entire reaction system a short-cut nitrification-denitrification coupled anaerobic ammonia oxidation denitrification reaction system. With the center plane of the reactor tank 3 as the boundary, the DO in the lower part is 1ppm±0.5, and the DO in the upper part is <0.2ppm.
[0038] High-concentration (300-1500ppm) nitrogen-containing wastewater enters the distributor 2 through the high-pressure water pump 16. The wastewater flows through the main pipe 30 of the distributor 2 into each ring coil 26. The bottom sludge is disturbed by the inclined pipe 24, and the upward flow velocity is generated by the riser pipe 25, so that the wastewater is evenly distributed and flows upward, avoiding dead corners where sludge accumulates and incomplete reactions occur.
[0039] Wastewater is brought into full contact with activated sludge at a certain upward flow velocity to carry out biochemical reactions. The entire tank system is regulated online through DO probe 20, temperature probe 11, ORP probe 10, pH probe 9, sampling port 12, and dosing port 8 to provide a good living environment. The activated sludge is ultimately blocked and enriched by the packing material 4 to obtain the required autotrophic bacteria. Other bacteria are not suitable for long-term survival under these conditions and are deflocculated and discharged from the system.
[0040] Nitrogen and water vapor produced by the biochemical reaction enter the gas-liquid separator 5. When water enters the gas-liquid separator 5 through the gas collection pipe 22, the overflowing water returns to the reactor tank 3 through the liquid discharge pipe 23, thus achieving the purpose of gas-liquid separation. The waste gas discharge pipe 15 is connected to the centralized waste gas collection pipe at the back end.
[0041] The hydrocyclone 7 is powered by the circulating water pump 6. The function of the hydrocyclone separator is to separate old sludge and light component bacteria, while retaining surviving sludge and heavy component autotrophic bacteria. The activated sludge autotrophic bacteria are circulated back into the reactor tank 3, while the old sludge and light component bacteria are discharged from the system through the tail outlet pipe 14 and flow into the rear end. At the same time, the circulating water pump 6 increases the upward flow velocity in the reaction tank, so that the sewage and activated sludge can fully contact each other to achieve efficient denitrification reaction.
[0042] Example 2
[0043] The structure of this embodiment is the same as that of Embodiment 1. The difference is that when the required reaction system only requires an anaerobic ammonia oxidation denitrification system, and both the upper and lower DO concentrations are <0.2 ppm, the inlet valve 21 on the inlet pipe 1 is closed, and the inlet valve 21 on the bridging inlet pipe 19 is opened, allowing the inlet water to enter the distributor 2 through the bridging inlet pipe 19 for denitrification reaction. The rest is the same as in Embodiment 1.
Claims
1. A biochemical denitrification reactor, characterized in that: The reactor includes an inlet pipe (1), a reactor tank (3), a gas-liquid separator (5), a circulating water pump (6), a hydrocyclone (7), a high-pressure water pump (16), a gas-liquid mixer (18), and a bridging inlet pipe (19). A water distributor (2) is installed at the bottom of the reactor tank (3). The gas-liquid separator (5) is located at the top of the reactor tank (3). The reactor tank (3) is filled with packing material (4). The high-pressure water pump (16) is connected in parallel to the reactor tank (3) via an inlet pipe (1) and a bridging inlet pipe (19). An inlet pipe (1) is equipped with… The inlet valve (21) and gas-liquid mixer (18) are installed on the bridging inlet pipe (19); the circulating water pump (6) and hydrocyclone (7) are located outside the reactor tank (3); the hydrocyclone (7) is connected to the reactor tank (3) through the circulating pipeline; the circulating water pump (6) is installed on the circulating pipeline; the circulating pipeline has an addition port (8) for adding nutrient agents; the reactor tank (3) has a sampling port (12) and a mud feeding / discharging port (17) respectively, and is equipped with probes for monitoring different parameters.
2. The biochemical denitrification reactor according to claim 1, characterized in that: The packing material (4) is one or more, and each packing material (4) includes a packing brush (27) and a packing ring (29). The packing ring (29) is fixed on the inner wall of the reactor tank (3). There are multiple packing brushes (27) arranged circumferentially. One end of each packing brush (27) is connected to the packing ring (29), and the other end of each packing brush (27) is a free end. During the operation of the reactor, the other end of each packing brush (27) is suspended in the water.
3. The biochemical denitrification reactor according to claim 2, characterized in that: The packing (4) is located between the top liquid surface (31) inside the reactor tank (3) and the center plane of the reactor tank (3). The packing ring (29) is fixed by a buckle (28) pre-embedded in the inner wall of the reactor tank (3). The length of the packing brush (27) is 50% to 90% of the radius of the radial section circle of the reactor tank (3). The arrangement density of the packing brush (27) accounts for 50% to 95% of the radial section circle area of the reactor tank (3). The distance between the uppermost packing (4) and the top liquid surface inside the reactor tank (3) is 800 mm to 1500 mm.
4. The biochemical denitrification reactor according to claim 1, characterized in that: The water distributor (2) includes a coil (26), a main pipe (30), inclined pipes (24), and a riser (25). The coil (26) consists of multiple coils arranged concentrically. Each coil (26) is connected to the inlet pipe (1) from the center by the main pipe (30). Each coil (26) has multiple inclined pipes (24) with the same inclination direction in the circumferential shear direction. The inclined pipes (24) are connected to the inside of the coil (26). Each coil (26) has multiple risers (25) evenly arranged circumferentially on the upper surface of the upper surface of the coil (26). The lower end of each riser (25) is connected to the inside of the coil (26). Each riser (25) is provided with a float valve at the upper end.
5. The biochemical denitrification reactor according to claim 1, characterized in that: The gas-liquid separator (5) has a gas collection pipe (22) and a liquid discharge pipe (23). Both ends of the gas collection pipe (22) are funnel-shaped. The gas-liquid separator (5) is provided with a waste gas discharge pipe (15) that is connected to the centralized waste gas collection pipe at the rear end.
6. The biochemical denitrification reactor according to claim 5, characterized in that: The upper end of the gas collection pipe (22) is located inside the gas-liquid separator (5), and the lower end of the gas collection pipe (22) is located above the top liquid surface (31) inside the reactor tank (3); the upper end of the liquid discharge pipe (23) is connected to the bottom of the gas-liquid separator (5), and the lower end of the liquid discharge pipe (23) is located above the top liquid surface (31) inside the reactor tank (3).
7. The biochemical denitrification reactor according to claim 1, characterized in that: The inlet of the circulating water pump (6) is connected to the reactor tank (3) through the circulating pipeline B (32), the outlet of the circulating water pump (6) is connected to the inlet of the hydrocyclone (7), the outlet of the hydrocyclone (7) is connected to the reactor tank (3) through the circulating pipeline A (13), the dosing port (8) is set on the circulating pipeline A (13), and the hydrocyclone (7) is provided with a tail end outlet pipe (14).
8. The biochemical denitrification reactor according to claim 7, characterized in that: The connection point between the circulation pipeline B (32) and the reactor tank (3) is located between the top liquid surface (31) and the uppermost packing (4) inside the reactor tank (3), and the connection point between the circulation pipeline A (13) and the reactor tank (3) is located above the water distributor (2).
9. The biochemical denitrification reactor according to claim 1, characterized in that: The probes include a pH probe (9), an ORP probe (10), a temperature probe (11), and a DO probe (20). The ORP probe (10) and the temperature probe (11) are located at the middle position of the upper part of the effective liquid level of the reactor tank (3). There are two DO probes (20), located at the middle position of the upper part and the middle position of the lower part of the effective liquid level of the reactor tank (3), respectively. The pH probe (9) is located at the middle position of the lower part of the effective liquid level of the reactor tank (3), and together with the DO probe (20) below it, they are located on the left and right sides of the cross section in the height direction of the reactor tank (3).
10. The biochemical denitrification reactor according to claim 1, characterized in that: The reactor tank (3) has a diameter-to-height ratio of 1:1 to 5 and an upward flow velocity of 1 to 6 m / h.