Reactor and culture method for anaerobic ammonia oxidation granular sludge

Abstract

The invention discloses a reactor and a culture method for anaerobic ammonia oxidation granular sludge, and relates to the technical field of sewage treatment engineering. The aeration device and the water distribution device are arranged at the bottom of the reactor tank body; the first precipitation separation module is arranged at the upper half part of the reactor tank body and is communicated with the lower part of the reactor tank body; and the second precipitation separation module is arranged outside the reactor tank body. Through a time-sharing aeration strategy and precise nutrition regulation and control, the granulation period is greatly shortened, and the average particle size and the structural density of the granular sludge are improved; the flow field design is optimized, the stability and impact resistance of the granular sludge are enhanced, and the strain activity and treatment capacity are improved; industrial operation parameters are clear, the method is suitable for treating different types of high-ammonia-nitrogen wastewater, and the universality is high; a precipitation separation module is arranged, particles are efficiently intercepted, biomass stability is maintained, long-term stable operation of the system is guaranteed, operation is easy and convenient, maintenance is easy, and the labor cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment engineering technology, and in particular relates to a reactor and cultivation method for anaerobic ammonia oxidation granular sludge. Background Technology

[0002] Anaerobic ammonia oxidation (AAO) technology, with its significant advantages such as low energy consumption, low sludge production, and no need for external carbon sources, has become one of the core technologies for denitrification treatment of high ammonia nitrogen wastewater. This technology is widely used in municipal and industrial wastewater treatment and is of great significance in solving the problem of high ammonia nitrogen wastewater pollution.

[0003] Despite the numerous advantages of anammox technology, its industrial application still faces several key challenges, primarily in the formation and stable growth of anammox granular sludge. Specifically, the success of granular sludge cultivation hinges on a uniform fluidization effect within the reactor, precise aeration control, and efficient particle retention capacity. However, existing aerated fluidized bed reactors exhibit the following significant drawbacks when used for anammox granular sludge cultivation:

[0004] Unreasonable aeration system design: Traditional reactors often use a single aeration pipe or uniformly distributed aeration heads, resulting in poor aeration uniformity, local flow field disturbances within the reactor, dead zones or excessive fluidization, which is not conducive to the aggregation and granulation of anaerobic ammonia oxidizing bacteria, resulting in low granulation efficiency.

[0005] Poor particle retention: The lack of targeted particle retention and recirculation structures makes it easy for granular sludge to be lost with the effluent, making it difficult to maintain the biomass concentration in the reactor and affecting the stability of the system; Although some reactors are equipped with interception devices, the pore size is fixed and cannot be adapted to the needs of different stages of granulation, thus limiting the retention effect.

[0006] Poor flow field adaptability: There is no dedicated flow field optimization structure inside the reactor, the water flow state is difficult to control, and the gas-liquid-solid three-phase contact is insufficient, which not only affects the metabolism of microorganisms and the granulation process, but also easily leads to the deposition or breakage of granular sludge.

[0007] Inconvenient maintenance and operation: Key components such as aerator heads and interception nets are mostly fixed installations, making disassembly, cleaning or replacement difficult. Long-term operation can easily lead to blockages, increasing maintenance costs and labor intensity.

[0008] Existing upflow packed bed reactors improve sludge retention by adding suspended packing material, but their fixed aeration mode prevents gradient aeration and lacks internal flow field optimization design, resulting in long granulation cycles and failing to meet the demands of high-efficiency industrial cultivation. Therefore, there is an urgent need to design an optimized, precisely aerated, highly efficient, and easily maintained aerated fluidized bed reactor suitable for the industrial cultivation of anaerobic ammonia oxidation granular sludge.

[0009] In addition, the slow growth rate of anaerobic ammonia oxidizing bacteria (doubling time as long as 10-14 days) and high sensitivity to environmental conditions (temperature, pH, dissolved oxygen, etc.) result in low granulation efficiency and insufficient stability in the reactor, which has become a key bottleneck restricting the large-scale industrial promotion of this technology.

[0010] The existing granular sludge cultivation process and related technologies have the following core defects:

[0011] Inappropriate aeration strategy: Traditional aerated aerobic beds mostly adopt a uniform aeration mode, which cannot dynamically adjust the aeration intensity according to the granulation process, resulting in turbulent flow field, poor bacterial aggregation effect, and a granulation cycle of 45-60 days, which is inefficient.

[0012] Inappropriate nutrient ratio: The lack of a dedicated nutrient system for granular anaerobic ammonia oxidizing bacteria and the absence of clear standards for the addition of trace elements result in insufficient bacterial activity, loose granular sludge structure, and weak shock resistance.

[0013] Poor industrial adaptability: Most existing technologies remain in the laboratory or pilot stage, and the key parameters for industrial operation (such as influent load gradient, hydraulic retention time control range, etc.) are not clearly defined. The scale-up effect is obvious, and the denitrification efficiency fluctuates greatly in actual applications (ammonia nitrogen removal rate is only 75-80%).

[0014] Poor particle retention: The internal flow field design of the reactor is unreasonable, and there is a lack of targeted particle return and retention mechanisms. Particle sludge is easily lost with the effluent, making it difficult to maintain a stable biomass concentration in the reactor.

[0015] Taking patent CN102432097B as an example, it discloses a method for rapid start-up of anaerobic ammonia oxidation in an upflow packed bed reactor. Although it improves sludge retention by adding suspended packing material, it does not involve dynamic optimization of the aeration strategy, the granulation cycle is still relatively long, and it does not specify the nutrient ratio and load enhancement scheme for industrial applications, making it difficult to meet the high-efficiency and stable requirements of large-scale wastewater treatment. Based on the above reasons, this application provides a method for cultivating granular sludge in anaerobic ammonia oxidation to solve the core problems of low granulation efficiency and long cycle in traditional processes. Summary of the Invention

[0016] The purpose of this invention is to provide a reactor and cultivation method for anaerobic ammonia oxidation granular sludge. By optimizing aeration strategies, flow field design, and particle retention mechanisms, the cultivation efficiency and stability of granular sludge are improved, providing an effective solution for the industrial treatment of high ammonia nitrogen wastewater.

[0017] In a first aspect, embodiments of this application provide a reactor for anaerobic ammonia oxidation of granular sludge, comprising a reactor tank, an aeration device and a water distribution device installed at the bottom of the reactor tank, a first sedimentation separation module installed in the upper half of the reactor tank and communicating with its lower half, and a second sedimentation separation module disposed outside the reactor tank; the first sedimentation separation module is installed and fixed by a fixed bracket fixed to the inner wall of the reactor tank; the first sedimentation separation module is connected to the second sedimentation separation module through a drainage pipe; the second sedimentation separation module is connected to the bottom of the reactor tank through a sludge return pipe, and a sludge pump is provided on the sludge return pipe; the first sedimentation separation module is provided with a first guide plate and a second guide plate to guide the water flow to form an up-and-down baffle.

[0018] As a preferred embodiment of the present invention, a water temperature heating control device is installed in the lower half of the reactor tank; the water temperature heating control device includes a thermocouple spiral coil installed in the lower half of the reactor tank, a temperature controller installed outside the reactor tank, and a temperature sensor installed through the reactor tank.

[0019] As a preferred embodiment of the present invention, the water distribution device includes a main water inlet pipe; the main water inlet pipe is connected to two branch water inlet pipes that penetrate into the interior of the reactor tank; the portion of the branch water inlet pipe located inside the reactor tank is provided with φ20 water distribution holes at intervals of 30cm; the two branch water inlet pipes extend out of the opposite tank walls of the reactor tank and are provided with rinsing ports.

[0020] As a preferred embodiment of the present invention, the lower end of the reactor tank is provided with a manhole, a lower outlet and a sludge inlet; the sludge inlet is connected to the sludge return pipe; and a level gauge is installed on the outer wall of the upper end of the reactor tank.

[0021] As a preferred embodiment of the present invention, the aeration device includes a first air-guiding annular pipe and a second air-guiding annular pipe coaxially installed at the bottom of the reactor tank; a plurality of aeration discs are respectively installed on the first air-guiding annular pipe and the second air-guiding annular pipe; the first air-guiding annular pipe is connected to a first air inlet pipe extending upward along the inner wall of the reactor tank and extending out from the upper end side wall of the reactor tank; the second air-guiding annular pipe is connected to a second air inlet pipe extending upward along the inner wall of the reactor tank and extending out from the upper end side wall of the reactor tank.

[0022] As a preferred embodiment of the present invention, the first guide plate is disposed at the inlet of the first sedimentation separation module for oblique downward flow; a conical hopper is disposed below the first guide plate; the lower end of the conical hopper is connected to a microbial reflux conduit leading to the bottom of the reactor tank; a second guide plate extending obliquely upward is disposed above the conical hopper; an outlet weir is disposed above the second guide plate; the outlet weir is connected to an upper outlet disposed on the outer wall of the reactor tank; and the upper end of the drainage pipe is connected to the upper outlet.

[0023] As a preferred embodiment of the present invention, the tilt angle of the first guide plate is in the range of 40-80°; the tilt angle of the second guide plate is in the range of 40-80°.

[0024] As a preferred embodiment of the present invention, the upper half of the second sedimentation separation module is provided with an intercepting screen and the lower half is provided with an intercepting trough; a separation water inlet is provided in communication with the water inlet end of the intercepting screen; the separation water inlet is connected to the lower end of the drainage pipe; a drain outlet is provided in communication with the drainage end of the intercepting screen; the intercepting screen intercepts the material and transports it to the intercepting trough below; the intercepting trough is connected to the sludge return pipe.

[0025] Secondly, embodiments of this application provide a method for cultivating anaerobic ammonia oxidation granular sludge, comprising the following stages:

[0026] Microbial enrichment stage: After the protein separation wastewater anaerobic unit, the wastewater is directionally enriched and cultured in a culture reactor. The total nitrogen concentration of the wastewater is 280-350 mg / L, the ammonia nitrogen concentration is 200-300 mg / L, the COD is <500 mg / L, the phosphate concentration is 10-20 mg / L, the pH value is 7-8.5, the temperature is 30-35℃, and the operation is continuous for 15-20 days. Through aeration strategy and load control, the hydraulic retention time is gradually shortened and the influent ammonia nitrogen load is increased to achieve the directional screening and enrichment of dominant microbial groups. During this period, the concentrations of total nitrogen, ammonia nitrogen and nitrite in the effluent are monitored regularly. The sludge morphology changes from flocculent to dense granular, and the enrichment stage is completed when the particle size reaches 0.8-2.0 mm.

[0027] Granular culture and enhancement stage:

[0028] The reactor is inoculated with enriched anaerobic ammonia-oxidizing bacteria at a rate of 15%-20% of the effective volume of the reactor, and the initial sludge concentration is controlled at 5-8 gVSS / L.

[0029] Granulation monitoring and control: During the cultivation process, the particle morphology is monitored in real time using an optical microscope. When the number of particles increases to 25% and the newly generated particle size reaches 0.5 mm or more, the particle enhancement program is started, the aeration strategy and hydraulic retention time are adjusted, and the sludge enters the large-scale growth period.

[0030] Flow field and retention optimization: The first guide plate and the second guide plate in the first sedimentation separation module inside the reactor guide the water flow to form an up-and-down baffle, change the local hydraulic velocity, and enhance the hydraulic shear force; the second sedimentation separation module forms a particle retention and reflux mechanism to reduce particle loss.

[0031] As a preferred technical solution of the present invention, the load regulation specifically involves initially setting the hydraulic residence time to 24h, and gradually shortening it to 12-18h as the granulation process progresses; the influent ammonia nitrogen load is gradually increased from 0.2kgN / (m³・d) to 0.6-0.8kgN / (m³・d), with each load increase not exceeding 20%.

[0032] The nutrient ratio for the enrichment stage is as follows: Fe, Co, Ni, and chloramine complex trace element mixture are added to the basic culture medium at concentrations of 5-15 mg / L, 2-5 μg / L, 2-5 μg / L, and 3-5 μg / L, respectively. The C / N ratio is dynamically adjusted to 1.0-1.5 according to the influent water quality to meet the requirements for strain growth and granulation.

[0033] The aeration strategy specifically employs a time-segmented aeration strategy, creating anaerobic and anoxic environments at different times to ensure that ammonia nitrogen nitrification is controlled at the nitrification stage. The time-segmented aeration system gradually increases the aeration time according to the influent ammonia nitrogen load, as detailed below:

[0034] Initial stage (1-15 days): Aeration time is controlled at 20 minutes, and non-aeration time is controlled at 40 minutes.

[0035] Mid-term (16-45 days): Aeration time should be controlled at 20-25 minutes, and non-aeration time should be controlled at 35-40 minutes.

[0036] Mid-to-late stage (46-70 days): Aeration time should be controlled at 30-35 minutes, and non-aeration time should be controlled at 45-50 minutes.

[0037] Later stage (71-90 days): Aeration time should be controlled at 30-35 minutes, and non-aeration time should be controlled at 55-65 minutes.

[0038] The present invention has the following beneficial effects:

[0039] 1. This invention optimizes aeration strategies, such as using time-segmented aeration and precisely adjusting the aeration and non-aeration times according to different cultivation stages, as well as rationally controlling the nutrient ratio, creating a more suitable growth and aggregation environment for anaerobic ammonia-oxidizing bacteria, significantly shortening the formation cycle of granular sludge, accelerating the cultivation process, and improving cultivation efficiency.

[0040] 2. This invention, through its unique design, promotes the continuous growth of granular sludge during the cultivation process, resulting in an increase in average particle size. Simultaneously, the optimized cultivation conditions facilitate the optimization of the internal structure of the granules, making them more compact and enhancing the stability and shock resistance of the granular sludge.

[0041] 3. Through reasonable flow field design and nutrient supply, this invention enables anaerobic ammonia-oxidizing bacteria to fully obtain nutrients and a suitable living environment in granular sludge, thereby improving the activity of the bacteria and thus enhancing the overall metabolic activity and treatment capacity of the granular sludge.

[0042] 4. This invention clarifies a complete set of industrial operating parameters and control processes, which can be flexibly applied to different types and concentrations of high ammonia nitrogen wastewater treatment scenarios. It has strong versatility and adaptability, and provides an effective solution for the treatment of various types of high ammonia nitrogen wastewater.

[0043] 5. This invention, by setting up a first sedimentation separation module and a second sedimentation separation module, forms a particle retention and recirculation mechanism, effectively reducing the loss of granular sludge. In particular, the retention screen design in the second sedimentation separation module can precisely retain granular sludge, allowing it to return to the bottom of the reactor through the recirculation mechanism, maintaining the stability of biomass within the reactor. This efficient particle retention and recirculation mechanism, combined with a reasonable aeration and flow field design, ensures that the sludge concentration within the reactor remains at a relatively stable level, avoiding the adverse effects of excessively high or low sludge concentrations on treatment efficiency and system operation, thus guaranteeing the long-term stable operation of the system.

[0044] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0045] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a front view of the overall layout of a reactor for anaerobic ammonia oxidation of granular sludge according to the present invention.

[0047] Figure 2 This is a side view showing the overall layout of the reactor.

[0048] Figure 3 This is a diagram showing the bottom layout of the reactor.

[0049] Figure 4 This is a structural layout diagram of the first precipitation separation module.

[0050] Figure 5 This diagram shows the connection arrangement of the first sedimentation separation module, the second sedimentation separation module, the sludge return pipeline, the sludge pump, and the bottom of the reactor.

[0051] Figure 6 This is a photograph of anaerobic ammonia oxidation granular sludge cultivation.

[0052] Figure 7 This is a photo of anaerobic ammonia oxidation granular sludge after cultivation.

[0053] The attached diagram lists the components represented by each number as follows:

[0054] 1-Reactor tank, 2-Aeration device, 3-Water distribution device, 4-First sedimentation separation module, 5-Second sedimentation separation module, 6-Sludge return pipe, 7-Sludge pump, 8-Drainage pipe, 9-Water temperature heating control device, 11-Manhole, 12-Lower outlet, 13-Sludge inlet, 14-Level gauge, 21-First air guide ring pipe, 22-Second air guide ring pipe, 23-Aeration disc, 24-First air inlet pipe, 25-Second air inlet pipe, 31-Main water inlet pipe, 32-Branch water inlet pipe, 33-Flushing port, 41-First guide plate, 42-Conical part, 43-Bacterial inoculum return pipe, 44-Second guide plate, 45-Effluent weir, 46-Upper outlet, 51-Intercepting screen, 52-Intercepting trough, 53-Separation inlet interface, 54-Drainage outlet. Detailed Implementation

[0055] 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. Specific Implementation

[0056] Firstly, please refer to Figure 1-5 As shown in the figure, the pointed end indicates the direction of water flow. The present invention is a reactor for anaerobic ammonia oxidation of granular sludge, including a reactor tank 1, an aeration device 2 and a water distribution device 3 installed at the bottom of the reactor tank 1, a first sedimentation separation module 4 installed in the upper part of the reactor tank 1 and connected to its lower part, and a second sedimentation separation module 5 disposed outside the reactor tank 1.

[0057] The first sedimentation separation module 4 is fixedly installed on the inner wall of the reactor tank 1 by a fixed bracket. The first sedimentation separation module 4 is connected to the second sedimentation separation module 5 through a drainage pipe 8. The second sedimentation separation module 5 is connected to the bottom of the reactor tank 1 through a sludge return pipe 6, and a sludge pump 7 is installed on the sludge return pipe 6.

[0058] The reactor tank 1 is equipped with a manhole 11, a lower outlet 12, and a sludge inlet 13 at its lower end. The sludge inlet 13 is connected to the sludge return pipe 6. A level gauge 14 is installed on the outer wall of the upper end of the reactor tank 1. The reactor tank 1 has a cylindrical design with a height-to-diameter ratio of 2-2.5:1 and an effective volume of 42 m³, ensuring sufficient reaction space.

[0059] The lower half of the reactor tank 1 is equipped with a water temperature heating control device 9. The water temperature heating control device 9 includes a thermocouple spiral coil installed in the lower half of the reactor tank 1, a temperature controller installed outside the reactor tank 1, and a temperature sensor installed through the reactor tank 1, which precisely controls the reaction temperature between 30-35℃.

[0060] The aeration device 2 includes a first air-guiding annular pipe 21 and a second air-guiding annular pipe 22 coaxially installed at the bottom of the reactor tank 1. Several aeration discs 23 are respectively installed on the first and second air-guiding annular pipes 21 and 22. The aeration discs 23 have a pore size of 50-100 μm, resulting in fine aeration bubbles and a large gas-liquid contact area, thus improving oxygen utilization. The first air-guiding annular pipe 21 is connected to a first air inlet pipe 24 extending upward along the inner wall of the reactor tank 1 and extending out from the upper side wall of the reactor tank 1. The second air-guiding annular pipe 22 is connected to a second air inlet pipe 25 extending upward along the inner wall of the reactor tank 1 and extending out from the upper side wall of the reactor tank 1. The first and second air inlet pipes 24 and 25 are respectively connected to an external air source to achieve time-sharing aeration control.

[0061] The water distribution device 3 includes a main inlet pipe 31. The main inlet pipe 31 connects to two branch inlet pipes 32 that extend into the reactor tank 1. The portion of the branch inlet pipes 32 located inside the reactor tank 1 has φ20 water distribution holes spaced 30cm apart to ensure uniform wastewater distribution, avoid localized flow disturbances, and provide a stable environment for bacterial aggregation. The two branch inlet pipes 32 extend out of the opposite walls of the reactor tank 1 and are equipped with flushing ports 33 for periodic flushing to prevent clogging.

[0062] The first sedimentation separation module 4 is equipped with a first guide plate 41 and a second guide plate 44 to guide the water flow into vertical deflection, enhancing hydraulic shear force and promoting particle formation. The first guide plate 41 is positioned at the inlet of the first sedimentation separation module 4 for downward oblique flow guidance. A conical section 42 is located below the first guide plate 41. The lower end of the conical section 42 is connected to a microbial reflux conduit 43 leading to the bottom of the reactor tank 1. A second guide plate 44 extends obliquely upward at the upper part of the conical section 42. An outlet weir 45 is located above the second guide plate 44. The outlet weir 45 is connected to an upper outlet 46 located on the outer wall of the reactor tank 1. The upper end of the drainage pipe 8 is connected to the upper outlet 46. The inclination angle of the first guide plate 41 ranges from 40° to 80°. The inclination angle of the second guide plate 44 also ranges from 40° to 80°.

[0063] The second sedimentation separation module 5 is equipped with an intercepting screen 51 in the upper part and an intercepting trough 52 in the lower part, forming a particle interception and return mechanism to reduce particle loss. A separation inlet interface 53 is provided, which is connected to the inlet end of the intercepting screen 51. The separation inlet interface is connected to the lower end of the drainage pipe 8. A drain outlet 54 is provided, which is connected to the drain end of the intercepting screen 51. The intercepted material from the intercepting screen 51 is transported to the lower intercepting trough 52. The intercepting trough 52 is connected to the sludge return pipe 6.

[0064] The specific process steps for cultivating anaerobic ammonia oxidation granular sludge in an optimized reactor are as follows:

[0065] 1. Wastewater Inlet and Distribution: Wastewater Source: Wastewater enters the system through the main inlet pipe 31. Distribution System: Wastewater enters the bottom of the culture reactor through the inlet branch pipe 32. φ20 water distribution holes are installed on the inlet branch pipe 32 every 30cm to ensure that the wastewater is evenly distributed at the bottom of the reactor. Periodic Flushing: The inlet branch pipe 32 extends towards the opposite tank wall and is equipped with a flushing port 22. The inlet branch pipe is periodically flushed to prevent the water distribution holes from becoming clogged.

[0066] 2. Inoculation and Mixing of Microbial Strains: Inoculation: The enriched anaerobic ammonia-oxidizing bacteria are inoculated into the reactor at a rate of 15%-20% of the effective reactor volume. The initial sludge concentration is controlled at 5-8 g VSS / L. Wastewater and Microbial Strain Mixing: After entering the reactor through the water distribution holes, the wastewater is thoroughly mixed with the inoculated ammonia-oxidizing bacteria. The ammonia nitrogen in the wastewater is converted into nitrogen gas by the ammonia-oxidizing bacteria.

[0067] 3. Aeration System: Aeration Device 2: Air enters the aeration disc 23 fixed at the bottom of the culture reactor through the first air guide annular pipe 21 and the second air guide annular pipe 22. Air Supply: Air is supplied by a blower. The blower's operating time is controlled by an external automatic control program, and the air volume is adjusted through valves on the aeration branch pipes. Time-Segmented Aeration Strategy: Initial Stage (1-15 days): Aeration time 20 min, non-aeration time 40 min, promoting bacterial adaptation and proliferation. Middle Stage (16-45 days): Aeration time 20-25 min, non-aeration time 35-40 min, promoting particle growth. Mid-to-Late Stage (46-70 days): Aeration time 30-35 min, non-aeration time 45-50 min, promoting rapid particle growth. Late Stage (71-90 days): Aeration time 30-35 min, non-aeration time 55-65 min, maintaining stable particle fluidization and stable operation.

[0068] 4. Formation of fluidized state: Mixing and movement: Wastewater, ammonia-oxidizing bacteria, and air are fully mixed in the reactor and move up and down along the height of the tank to form a fluidized state, which promotes the contact and reaction between the bacteria and the wastewater.

[0069] 5. Sedimentation and Separation: First Sedimentation Separation Module: Entering Module: The treated wastewater and ammonia-oxidizing bacteria enter the first sedimentation separation module 4 at the top of the reactor, entering through the first guide plate 41 of the sedimentation separator module; Separation of Bacteria and Water: The bacteria enter the conical section 42 along the 8 sets of channels, where they are separated from the water under gravity; Reflux and Effluent: After separation, water and a small amount of bacteria flow upwards along the second guide plate 44 and enter the effluent weir 45. The separated ammonia-oxidizing bacteria return to the bottom of the reactor along the bacteria reflux conduit 43. Second Sedimentation Separation Module: Entering Module Two: Water entering the effluent weir 45 enters the second sedimentation separation module 5 through the drainage pipe 8 and the separation inlet 53. Retention and Drainage: Water flows downwards along the retention screen 51, enters the separation module through the screen, and is discharged through the drain outlet 54. The bacteria retained on the surface of the retention screen 51 flow into the retention tank 52. Microbial inoculum return: The microbial inoculum in the interception tank 52 enters the sludge pump 7 through the sludge return pipe 6, is transported to the sludge inlet 13 of the culture reactor, and then enters the bottom of the reactor, forming a particle return mechanism.

[0070] 6. Granulation Monitoring and Control: Real-time Monitoring: Particle morphology is monitored in real time using an optical microscope during the cultivation process. Particle Enhancement: When the particle count increases to 25% and the newly generated particle size reaches 0.5 mm or larger, the particle enhancement program is activated, adjusting the aeration time, aeration intensity, and hydraulic retention time to initiate the sludge mass growth phase. Flow Field and Retention Optimization: Baffle Plate Design: The first guide plate 41 and the second guide plate 42 in the first sedimentation separation module 4 inside the reactor guide the water flow to form up-and-down baffles, changing the local hydraulic velocity, strengthening the hydraulic shear force, and promoting particle formation. Secondary Sludge-Water Separation: The second sedimentation separation module 5 forms a particle retention and recirculation mechanism, reducing particle loss and maintaining the stability of biomass within the reactor.

[0071] 7. Operating load control: Hydraulic retention time: initially set at 24h, gradually shortened to 12-18h as the granulation process progresses. Influent ammonia nitrogen load: gradually increased from 0.2kgN / (m³・d) to 0.6-0.8kgN / (m³・d), with each load increase not exceeding 20% ​​to ensure bacterial adaptation.

[0072] Based on the same inventive concept, please refer to Figure 6-7 As shown in the embodiment of this application, a method for cultivating anaerobic ammonia oxidation granular sludge is provided. The strain source is anaerobic ammonia oxidation functional strains screened from the anaerobic reactor sludge and aerobic activated sludge of Shandong Guohong Protein Separation Wastewater Treatment Plant to ensure the strains' resistance to pollution and environmental adaptability. The cultivation method includes the following stages:

[0073] Microbial enrichment stage: After the protein separation wastewater anaerobic unit, the wastewater is directionally enriched and cultured in a culture reactor. The total nitrogen concentration of the wastewater is 280-350 mg / L, the ammonia nitrogen concentration is 200-300 mg / L, the COD is <500 mg / L, the phosphate concentration is 10-20 mg / L, the pH value is 7-8.5, the temperature is 30-35℃, and the operation is continuous for 15-20 days. Through aeration strategy and load control, the hydraulic retention time is gradually shortened and the influent ammonia nitrogen load is increased to achieve the directional screening and enrichment of dominant microbial groups. During this period, the concentrations of total nitrogen, ammonia nitrogen and nitrite in the effluent are monitored regularly. The sludge morphology changes from flocculent to dense granular, and the enrichment stage is completed when the particle size reaches 0.8-2.0 mm.

[0074] Nutrient ratio optimization during the enrichment stage: Add a mixture of complex trace elements such as Fe, Co, Ni, and chloramine to the basic culture medium at concentrations of 5-15 mg / L, 2-5 μg / L, 2-5 μg / L, and 3-5 μg / L, respectively. Dynamically adjust the C / N ratio to 1.0-1.5 according to the influent water quality to meet the requirements for strain growth and granulation.

[0075] Granular culture and enhancement stage:

[0076] The reactor is inoculated with enriched anaerobic ammonia-oxidizing bacteria. The inoculation amount is 15%-20% of the effective volume of the reactor, and the initial sludge concentration is controlled at 5-8 gVSS / L.

[0077] Granulation monitoring and control: During the cultivation process, the particle morphology is monitored in real time using an optical microscope. When the number of particles increases to 25% and the newly generated particle size reaches 0.5 mm or more, the particle enhancement program is started, the aeration strategy and hydraulic retention time are adjusted, and the sludge enters the large-scale growth period.

[0078] Flow field and retention optimization: The first guide plate 41 and the second guide plate 44 in the first sedimentation separation module 4 inside the reactor guide the water flow to form an up-and-down baffle, changing the local hydraulic velocity and strengthening the hydraulic shear force. The second sedimentation separation module 5 forms a particle retention and reflux mechanism to reduce particle loss.

[0079] Specifically, the load regulation involves initially setting the hydraulic retention time to 24 hours, which is gradually shortened to 12-18 hours as the granulation process progresses. The influent ammonia nitrogen load is gradually increased from 0.2 kgN / (m³・d) to 0.6-0.8 kgN / (m³・d), with each load increase not exceeding 20%.

[0080] The aeration strategy specifically involves employing a time-segmented aeration approach. This creates anaerobic and anoxic environments at different times to ensure that ammonia nitrogen nitrification is controlled at the nitrification stage. The time-segmented aeration system gradually increases the aeration time based on the influent ammonia nitrogen load. The specific process is as follows:

[0081] Initial stage (1-15 days): Aeration time is controlled at 20 minutes, and non-aeration time is controlled at 40 minutes.

[0082] Mid-term (16-45 days): Aeration time should be controlled at 20-25 minutes, and non-aeration time should be controlled at 35-40 minutes.

[0083] Mid-to-late stage (46-70 days): Aeration time should be controlled at 30-35 minutes, and non-aeration time should be controlled at 45-50 minutes.

[0084] Later stage (71-90 days): Aeration time should be controlled at 30-35 minutes, and non-aeration time should be controlled at 55-65 minutes.

[0085] The table below compares the experimental data of this cultivation method with that of the traditional process:

[0086] index Traditional crafts Technical solution of the present invention Improvement effect Granulation cycle (days) 90-120 60-90 Shorten by 20%-30% Ammonia nitrogen removal rate (%) 75-80 85-90 Increase by 5-10 percentage points Nitrite nitrogen removal rate (%) 80-90 ≥95 Increase by 5-15 percentage points Average particle size (mm) 0.3-0.6 1-3 Increase by 67%-100% Operating energy consumption (kWh / m³ water) 0.8-1.0 0.6-0.8 Reduced by 15%-20% Particle retention rate (%) 70-80 ≥95 Increase by 15-25 percentage points Continuous stable operation time (months) ≤2 ≥4 Extend by more than 100%

[0087] Compared to traditional processes and technologies, this application has the following characteristics:

[0088] Significantly improved granulation efficiency: Through time-sharing aeration strategies and precise nutrient regulation, the rapid growth cycle of granules is shortened to 45-60 days, which is 20%-30% shorter than traditional processes. The average particle size of granular sludge can reach 1-3mm, with a dense structure and a settling velocity ≥10.0m / h.

[0089] Stable and efficient denitrification performance: ammonia nitrogen removal rate of granular sludge ≥90%, nitrite nitrogen removal rate ≥95%, which is 5-15 percentage points higher than traditional processes; when the influent ammonia nitrogen concentration fluctuates by ±30%, the treatment efficiency fluctuation does not exceed 5%, and the ability to resist shock loads is significantly enhanced.

[0090] Strong industrial applicability: The complete set of industrial operation parameters and control processes have been defined. No external carbon source is required. The energy consumption is reduced by 15%-20% compared with traditional processes (down to 0.6-0.8 kWh / m³ water). It can be directly applied to different types of high ammonia nitrogen wastewater treatment scenarios such as fermentation, chemical industry, aquaculture, and landfill leachate.

[0091] High system stability: Through the design of the second sedimentation and separation module 5, the granular sludge retention rate is ≥95%, the sludge concentration in the reactor is stable at 15-20gVSS / L, and there is no significant particle loss or efficiency decline after 3 months of continuous operation, meeting the requirements for long-term industrial operation.

[0092] Easy to operate and maintain: All parameters can be precisely controlled through the automated control system, eliminating the need for complex operations, reducing labor costs, and facilitating large-scale promotion and application.

[0093] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0094] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A reactor for anaerobic ammonia oxidation of granular sludge, characterized in that: It includes a reactor tank (1), an aeration device (2) and a water distribution device (3) installed at the bottom of the reactor tank (1), a first sedimentation separation module (4) installed in the upper half of the reactor tank (1) and connected to its lower half, and a second sedimentation separation module (5) set outside the reactor tank (1). The first sedimentation separation module (4) is installed and fixed by a fixed bracket fixed to the inner wall of the reactor tank (1); The first sedimentation separation module (4) is connected to the second sedimentation separation module (5) through a drainage pipe (8); The second sedimentation separation module (5) is connected to the bottom of the reactor tank (1) through a sludge return pipe (6), and a sludge pump (7) is installed on the sludge return pipe (6). The first sedimentation separation module (4) is provided with a first guide plate (41) and a second guide plate (44) to guide the water flow to form an up and down flow.

2. The reactor for anaerobic ammonia oxidation of granular sludge according to claim 1, characterized in that, The lower half of the reactor tank (1) is equipped with a water temperature heating control device (9); the water temperature heating control device (9) includes a thermocouple spiral coil installed in the lower half of the reactor tank (1), a temperature controller installed outside the reactor tank (1), and a temperature sensor installed through the reactor tank (1).

3. The reactor for anaerobic ammonia oxidation of granular sludge according to claim 1, characterized in that, The water distribution device (3) includes a main water inlet pipe (31); the main water inlet pipe (31) is connected to two branch water inlet pipes (32) that penetrate into the reactor tank (1); the branch water inlet pipes (32) located inside the reactor tank (1) are provided with φ20 water distribution holes every 30cm; the two branch water inlet pipes (32) extend out of the opposite tank walls of the reactor tank (1) and are provided with flushing ports (33).

4. The reactor for anaerobic ammonia oxidation of granular sludge according to claim 1, characterized in that, The reactor tank (1) is provided with a manhole (11), a lower outlet (12) and a sludge inlet (13) at the lower end; the sludge inlet (13) is connected to the sludge return pipe (6); a level gauge (14) is installed on the outer wall of the upper end of the reactor tank (1).

5. The reactor for anaerobic ammonia oxidation of granular sludge according to claim 1, characterized in that, The aeration device (2) includes a first air guide annular pipe (21) and a second air guide annular pipe (22) coaxially installed at the bottom of the reactor tank (1); a plurality of aeration discs (23) are respectively installed on the first air guide annular pipe (21) and the second air guide annular pipe (22); the first air guide annular pipe (21) is connected to a first air inlet pipe (24) extending upward along the inner wall of the reactor tank (1) and extending out from the upper end side wall of the reactor tank (1); the second air guide annular pipe (22) is connected to a second air inlet pipe (25) extending upward along the inner wall of the reactor tank (1) and extending out from the upper end side wall of the reactor tank (1).

6. The reactor for anaerobic ammonia oxidation of granular sludge according to claim 1, characterized in that, The first guide plate (41) is set at the inlet of the first sedimentation separation module (4) for diagonal downward flow guidance; a cone-shaped part (42) is set below the first guide plate (41); the lower end of the cone-shaped part (42) is connected to the microbial reflux conduit (43) leading to the bottom of the reactor tank (1); a second guide plate (44) extending diagonally upward is set on the upper part of the cone-shaped part (42); an outlet weir (45) is set above the second guide plate (44); the outlet weir (45) is connected to the upper outlet (46) set on the outer wall of the reactor tank (1); the upper end of the drainage pipe (8) is connected to the upper outlet (46).

7. The reactor for anaerobic ammonia oxidation of granular sludge according to claim 6, characterized in that, The tilt angle of the first guide vane (41) is 40-80°; the tilt angle of the second guide vane (44) is 40-80°.

8. The reactor for anaerobic ammonia oxidation of granular sludge according to claim 1, characterized in that, The second sedimentation separation module (5) is provided with an intercepting screen (51) in the upper half and an intercepting trough (52) in the lower half; a separation water inlet (53) is provided in connection with the water inlet end of the intercepting screen (51); the separation water inlet is connected to the lower end of the drainage pipe (8); a drain outlet (54) is provided in connection with the drain end of the intercepting screen (51); the intercepting screen (51) intercepts the material and transports it to the intercepting trough (52) below; the intercepting trough (52) is connected to the sludge return pipe (6).

9. The method for cultivating anaerobic ammonia oxidation granular sludge according to any one of claims 1-8, characterized in that, Includes the following stages: Microbial enrichment stage: After the protein separation wastewater anaerobic unit, the wastewater is directionally enriched and cultured in a culture reactor. The total nitrogen concentration of the wastewater is 280-350 mg / L, the ammonia nitrogen concentration is 200-300 mg / L, COD < 500 mg / L, phosphate concentration is 10-20 mg / L, pH value is 7-8.5, temperature is 30-35℃, and it is continuously operated for 15-20 days. Through aeration strategy and load control, the hydraulic retention time is gradually shortened and the influent ammonia nitrogen load is increased to achieve the directional screening and enrichment of dominant microbial groups. During this period, the concentrations of total nitrogen, ammonia nitrogen and nitrite in the effluent are monitored regularly. The sludge morphology changes from flocculent to dense granular. When the particle size reaches 0.8-2.0 mm, the enrichment stage is completed. Granular culture and enhancement stage: The reactor is inoculated with enriched anaerobic ammonia-oxidizing bacteria at a rate of 15%-20% of the effective volume of the reactor, and the initial sludge concentration is controlled at 5-8 gVSS / L. Granulation monitoring and control: During the cultivation process, the particle morphology is monitored in real time using an optical microscope. When the number of particles increases to 25% and the newly generated particle size reaches 0.5 mm or more, the particle enhancement program is started, the aeration strategy and hydraulic retention time are adjusted, and the sludge enters the large-scale growth period. Flow field and interception optimization: The first guide plate (41) and the second guide plate (44) in the first sedimentation separation module (4) set inside the reactor guide the water flow to form an up and down flow, change the local hydraulic velocity, and strengthen the hydraulic shear force; the second sedimentation separation module (5) set up forms a particle interception and reflux mechanism to reduce particle loss.

10. The method for cultivating anaerobic ammonia oxidation granular sludge according to claim 9, characterized in that, The nutrient ratio for the enrichment stage is as follows: Fe, Co, Ni, and chloramine complex trace element mixture are added to the basic culture medium at concentrations of 5-15 mg / L, 2-5 μg / L, 2-5 μg / L, and 3-5 μg / L, respectively. The C / N ratio is dynamically adjusted to 1.0-1.5 according to the influent water quality to meet the requirements for strain growth and granulation. The specific load control involves initially setting the hydraulic retention time to 24 hours, gradually shortening it to 12-18 hours as the granulation process progresses; and gradually increasing the influent ammonia nitrogen load from 0.2 kgN / (m³・d) to 0.6-0.8 kgN / (m³・d), with each load increase not exceeding 20%. The aeration strategy specifically employs a time-segmented aeration strategy, creating anaerobic and anoxic environments at different times to ensure that ammonia nitrogen nitrification is controlled at the nitrification stage. The time-segmented aeration system gradually increases the aeration time according to the influent ammonia nitrogen load, as detailed below: Initial stage (1-15 days): Aeration time should be controlled at 20 minutes, and non-aeration time should be controlled at 40 minutes; Mid-term (16-45 days): Aeration time should be controlled at 20-25 minutes, and non-aeration time should be controlled at 35-40 minutes; Mid-to-late stage (46-70 days): Aeration time should be controlled at 30-35 minutes, and non-aeration time should be controlled at 45-50 minutes; Later stage (71-90 days): Aeration time should be controlled at 30-35 minutes, and non-aeration time should be controlled at 55-65 minutes.

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