Method for realizing short-cut denitrification-anaerobic ammonia oxidation low-consumption deep denitrification based on MBBR (Moving Bed Biofilm Reactor)

Abstract

The invention discloses a method for realizing short-cut denitrification-anaerobic ammonia oxidation low-consumption deep denitrification based on an MBBR (Moving Bed Biofilm Reactor), and belongs to the technical field of water treatment. The technical problem that in the prior art, the dosage of a municipal tail water deep denitrification carbon source is large is solved. The method comprises the following steps: firstly, carrying out carrier biofilm culturing, introducing tail water subjected to biochemical treatment of a sewage plant into a pure membrane MBBR anoxic zone, adding a carbon source into the pure membrane MBBR anoxic zone to realize suspended carrier biofilm formation and denitrifying bacterium growth enrichment, and entering a short-cut denitrification domestication stage through C / N optimization after certain conditions are met; after the biological membrane domestication is completed, entering an anaerobic ammonia oxidation culture stage, and finally entering a stable operation stage. The limitation of low concentration of tail water bottom substances is overcome through the pure membrane MBBR, and conditions suitable for the Anammox reaction are created by tail water C / N regulation and raw water addition, so that high-standard low-consumption deep denitrification of the tail water is realized, and the requirement of an external carbon source is reduced.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to a low-consumption deep nitrogen removal method based on MBBR for short-cut denitrification-anaerobic ammonium oxidation. Background Technology

[0002] With increasingly stringent requirements for water environmental protection in my country and continuously raising the discharge standards of wastewater treatment plants, many localities have introduced local standards to control effluent indicators from wastewater treatment plants. As a result, the effluent quality of many existing urban wastewater treatment plants can no longer consistently meet the new discharge requirements. Among these challenges, the deep removal of total nitrogen (TN) is one of the core challenges facing the upgrading and renovation of wastewater treatment plants.

[0003] Upgrading existing wastewater treatment plants typically involves enhancing existing processes and constructing new post-treatment units. Compared to large-scale structural modifications to the existing biological treatment tanks, adding a separate "post-denitrification unit" after the biological treatment unit is considered a simpler, more flexible, and less impactful upgrade. This approach does not interfere with the operation of the main upstream processes, involves less engineering work, and has a shorter construction period, thus attracting widespread attention. However, post-denitrification processes (such as denitrification filters) are highly dependent on external carbon sources. Since readily biodegradable organic carbon sources are largely depleted in the effluent after complete upstream biological treatment, further advanced denitrification requires the addition of large amounts of external carbon sources. This not only significantly increases the operating costs of the wastewater treatment plant but also introduces risks associated with carbon source transportation, storage, precise dosing, and potential secondary pollution.

[0004] The rise of anaerobic ammonia oxidation (Anammox) technology has provided a new approach for low-consumption nitrogen removal. This technology requires no organic carbon source, directly oxidizing ammonia nitrogen using nitrite as an electron acceptor under anaerobic conditions, achieving direct nitrogen removal and theoretically saving 100% of the external carbon source. If the Anammox process can be applied to post-denitrification units, it can not only significantly reduce operating costs but also absorb a certain proportion of raw wastewater from the wastewater treatment plant (as a source of ammonia nitrogen) while treating effluent, thus sharing the treatment load of mainstream processes.

[0005] However, directly applying the Anammox process to the specific scenario of municipal wastewater treatment plant effluent presents a fundamental technical obstacle: Anammox bacteria are difficult to accumulate and maintain stably in effluent with extremely low substrate concentrations. Anammox bacteria grow slowly and are sensitive to the environment; their accumulation typically requires high concentrations of ammonia nitrogen and nitrite. Municipal effluent substrate concentrations are usually very low, leading to difficulties in their proliferation and long reactor start-up times.

[0006] This shows that the existing technology needs further improvement. Summary of the Invention

[0007] The purpose of this invention is to provide a low-consumption, deep nitrogen removal method based on MBBR for short-cut denitrification-anaerobic ammonium oxidation.

[0008] By overcoming the limitation of low substrate concentration in effluent through pure membrane MBBR, and by using effluent C / N regulation and raw water addition to create conditions suitable for Anammox reaction, high-standard, low-consumption deep denitrification of effluent is achieved, thereby reducing the demand for external carbon sources.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A low-consumption, deep nitrogen removal method based on MBBR for short-cut denitrification-anaerobic ammonium oxidation includes the following steps:

[0011] a. Carrier biofilm formation stage: The effluent from the biologically treated wastewater plant is introduced into the anoxic zone of the pure membrane MBBR. A carbon source is added to the anoxic zone to achieve suspended carrier biofilm formation and denitrifying bacteria growth and enrichment. The C / N ratio is 3-5. The effluent nitrate nitrogen concentration in the aerobic zone of the pure membrane MBBR after the anoxic zone is maintained at ≤10 mg / L until the biofilm thickness is >200 μm, the relative abundance of denitrifying bacteria is >20%, and the loading is greater than 0.8 kgN / m³. 3 / d, entering the short-cut denitrification acclimatization stage; the pollutant concentration in the effluent after biological treatment of the wastewater plant is 15~25mg / L;

[0012] b. Short-cut denitrification acclimatization stage: Add carbon source to the anoxic zone of the pure membrane MBBR to adjust and control the C / N ratio to 2-3, and maintain the effluent nitrate nitrogen concentration in the aerobic zone of the pure membrane MBBR ≤10mg / L until the nitrite nitrogen ratio in the effluent nitrate nitrogen is >80%, the biofilm thickness is >200μm, the relative abundance of denitrifying bacteria is >20%, and the short-cut denitrification load is >0.6kgN / m³. 3 / d, biofilm acclimatization is complete, and the culture enters the anaerobic ammonia oxidation stage;

[0013] c. Anaerobic ammonia oxidation cultivation stage: Municipal wastewater raw water and effluent from the wastewater treatment plant's biological treatment are introduced together into the anoxic zone of the pure membrane MBBR. The ammonia nitrogen concentration after mixing is controlled at 5-10 mg / L. Carbon sources are added to the anoxic zone of the pure membrane MBBR to provide nitrite for short-cut denitrification until the relative abundance of anaerobic ammonia oxidizing bacteria in the biofilm is >2% and the anaerobic ammonia oxidation load is greater than 0.4 kgN / m³. 3 / d, biofilm thickness >200μm, anaerobic ammonia oxidation culture completed, entered stable operation stage;

[0014] d. Stable operation phase: The municipal sewage raw water and the effluent from the sewage treatment plant after biological treatment are introduced into the anoxic zone of the pure membrane MBBR. The ammonia nitrogen concentration after mixing is controlled at 5~10mg / L. A carbon source is added to the anoxic zone of the pure membrane MBBR to provide nitrogenous residue for short-cut denitrification. Stable anaerobic ammonia oxidation denitrification is achieved in the anoxic zone of the pure membrane MBBR.

[0015] The above-mentioned method for low-consumption deep nitrogen removal based on MBBR for short-cut denitrification-anaerobic ammonia oxidation involves controlling the ammonia nitrogen concentration after mixing to 5-10 mg / L in step c. Then, considering the COD concentration of the municipal wastewater, the C / N ratio of the influent to the anoxic zone of the pure membrane MBBR is controlled by adjusting the carbon source dosage. Initially, the system operates at a C / N ratio of 2-3 for 4 hours, followed by a 2-hour cycle after stopping carbon source addition, until the anaerobic ammonia oxidation load exceeds 0.05 kgN / m³. 3 When the anaerobic ammonia oxidation load is greater than 0.1 kgN / m³, run the cycle for 5 hours with a C / N ratio of 2-3, then stop adding carbon source for 1 hour until the anaerobic ammonia oxidation load is greater than 0.1 kgN / m³. 3 At 1000 m³ / day, operate at a C / N ratio of 2-3 throughout the day; until the relative abundance of anaerobic ammonia-oxidizing bacteria in the biofilm is >2% and the anaerobic ammonia oxidation load is greater than 0.4 kgN / m³. 3 / d, biofilm thickness >200μm, anaerobic ammonia oxidation culture completed.

[0016] In the aforementioned method for low-consumption deep nitrogen removal via short-cut denitrification-anaerobic ammonia oxidation based on MBBR, in step d, after controlling the ammonia nitrogen concentration after mixing to 5~10 mg / L, and combining this with the COD concentration of the municipal wastewater, the C / N ratio of the influent to the anoxic zone of the pure membrane MBBR is controlled to be 2~3 by adjusting the carbon source dosage. This achieves stable anaerobic ammonia oxidation nitrogen removal in the anoxic zone of the pure membrane MBBR, while maintaining the nitrate nitrogen concentration in the effluent of the aerobic zone of the pure membrane MBBR ≤10 mg / L.

[0017] The above-mentioned method for low-consumption deep nitrogen removal based on MBBR to achieve short-cut denitrification-anaerobic ammonia oxidation can be implemented as follows: if the ammonia nitrogen in the effluent of the aerobic zone of the pure membrane MBBR is <1.5 mg / L and the COD is less than 40 mg / L, the DO in the aerobic zone of the pure membrane MBBR should be controlled at 1~2 mg / L; if the ammonia nitrogen in the effluent of the aerobic zone of the pure membrane MBBR is >1.5 mg / L or the COD is >40 mg / L, the DO in the aerobic zone of the pure membrane MBBR should be controlled at 2~4 mg / L.

[0018] The above-mentioned method for low-consumption deep nitrogen removal through short-cut denitrification-anaerobic ammonium oxidation based on MBBR involves adding suspended carriers to both the anoxic and aerobic zones of the pure membrane MBBR, with the filling rate of the suspended carriers being greater than 50%. In the aerobic zone of the pure membrane MBBR, the carriers attach to the membrane through aeration.

[0019] The aforementioned method for low-consumption, deep nitrogen removal via short-cut denitrification-anaerobic ammonium oxidation based on MBBR requires a pure membrane MBBR anoxic zone suspended carrier with an effective specific surface area ≥ 800 m². 2 / m 3 The specific gravity is 1.01–1.05; the effective specific surface area of ​​the suspended carrier in the aerobic zone of the pure membrane MBBR is ≥800 m². 2 / m 3 Its specific gravity is 0.94~0.97.

[0020] The above-mentioned method for low-consumption deep nitrogen removal based on MBBR to achieve short-cut denitrification-anaerobic ammonium oxidation has MLSS < 200 mg / L in the anoxic and aerobic zones of the pure membrane MBBR, and ORP ≤ -200 mV in the anoxic zone of the pure membrane MBBR.

[0021] The aforementioned method for low-consumption, deep nitrogen removal via short-cut denitrification-anaerobic ammonium oxidation based on MBBR involves installing a stirrer in the anoxic zone of the pure membrane MBBR, with a stirring power density of 5~15 W / m³. 3 Pool capacity.

[0022] Compared with the prior art, the present invention brings the following beneficial technical effects:

[0023] 1) Based on pure membrane MBBR, the problem of difficult enrichment of anaerobic ammonia oxidizing bacteria under low substrate conditions is solved, achieving a relative abundance of anaerobic ammonia oxidizing bacteria >2% and a denitrification load >0.4 kgN / m³. 3 / d;

[0024] 2) Reduce chemical consumption: Deep removal of TN is achieved through anaerobic ammonia oxidation, breaking the dilemma that deep denitrification of biological effluent relies entirely on carbon source addition, and chemical consumption can be reduced by more than 50%.

[0025] 3) Reduced operation and maintenance costs: While achieving low-consumption denitrification at the post-treatment stage, a certain proportion of raw water was also treated, reducing the energy and chemical consumption of the front-end nitrification and denitrification processes.

[0026] The method of this invention can significantly reduce the renovation and operation costs of wastewater treatment plants while meeting increasingly stringent environmental protection requirements. Attached Figure Description

[0027] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0028] This invention proposes a low-consumption, deep nitrogen removal method based on MBBR for short-cut denitrification-anaerobic ammonium oxidation. To make the advantages and technical solutions of this invention clearer and more explicit, the invention will be further described below with reference to specific embodiments.

[0029] The present invention introduces the effluent from the biochemical treatment of sewage treatment plants into the anoxic zone of a pure membrane MBBR. The difference between this invention and the raw water from sewage treatment plants in the prior art is that the low concentration of pollutants in the present invention makes it more difficult to enrich anaerobic ammonia oxidizing bacteria. To address this, the present invention proposes a method to match this.

[0030] like Figure 1 As shown, the system required by the present invention includes a sewage treatment plant biochemical treatment tank, a pure membrane MBBR anoxic zone, and a pure membrane MBBR aerobic zone. The pollutant concentration in the effluent after the sewage treatment plant biochemical treatment is 15~25mg / L. A portion of the raw sewage from the sewage treatment plant enters the pure membrane MBBR anoxic zone for simultaneous treatment.

[0031] A low-consumption, deep nitrogen removal method based on MBBR for short-cut denitrification-anaerobic ammonium oxidation includes the following steps:

[0032] Step 1: Carrier Biofilm Formation Stage: The effluent from the biologically treated wastewater plant is introduced into the anoxic zone of the pure membrane MBBR. A carbon source is added to the anoxic zone to achieve suspended carrier biofilm formation and denitrifying bacteria growth and enrichment. The C / N ratio is 3-5. The effluent nitrate nitrogen concentration in the aerobic zone of the pure membrane MBBR after the anoxic zone is maintained at ≤10 mg / L until the biofilm thickness is >200 μm, the relative abundance of denitrifying bacteria is >20%, and the loading is greater than 0.8 kgN / m³. 3 / d, entering the short-cut denitrification acclimatization stage; the pollutant concentration in the effluent after biological treatment of the wastewater plant is 15~25mg / L;

[0033] Step 2, Short-cut Denitrification Acclimation Stage: Add carbon source to the anoxic zone of the MBBR to adjust and control the C / N ratio to 2-3, maintaining the effluent nitrate nitrogen concentration in the aerobic zone of the pure membrane MBBR ≤10mg / L, until the nitrite nitrogen ratio in the effluent nitrate nitrogen is >80%, the biofilm thickness is >200μm, the relative abundance of denitrifying bacteria is >20%, and the short-cut denitrification load is >0.6kgN / m³. 3 / d, biofilm acclimatization is complete, and the culture enters the anaerobic ammonia oxidation stage;

[0034] Step 3: Anaerobic Ammonia Oxidation Cultivation Stage: Municipal wastewater raw water and effluent from the wastewater treatment plant's biochemical treatment are introduced together into the anoxic zone of the pure membrane MBBR. The ammonia nitrogen concentration after mixing is controlled between 5 and 10 mg / L. Combined with the raw water COD concentration, the influent C / N ratio is controlled by adjusting the external carbon source dosage. The system operates at a C / N ratio of 2-3 for 4 hours, followed by a 2-hour cycle after stopping carbon source addition, until the anaerobic ammonia oxidation load exceeds 0.05 kgN / m³. 3 When the anaerobic ammonia oxidation load is greater than 0.1 kgN / m³, run the cycle for 5 hours with a C / N ratio of 2-3, then stop adding carbon source for 1 hour until the anaerobic ammonia oxidation load is greater than 0.1 kgN / m³. 3At 10:00 AM / 10:00 PM, operate at a C / N ratio of 2-3 throughout the day until the relative abundance of anaerobic ammonia-oxidizing bacteria in the system biofilm is >2% and the anaerobic ammonia oxidation load is greater than 0.4 kgN / m³. 3 / d, biofilm thickness >200μm, anaerobic ammonia oxidation culture completed.

[0035] Step 4, Stable Operation Phase: Introduce municipal wastewater and effluent from the wastewater treatment plant's biological treatment process into the anoxic zone of the pure membrane MBBR. Control the ammonia nitrogen concentration after mixing to between 5 and 10 mg / L. Combined with the raw water COD concentration, adjust the influent C / N ratio to 2-3 by adjusting the external carbon source dosage. Achieve stable anaerobic ammonia oxidation denitrification in the pure membrane MBBR anoxic zone, maintaining the effluent nitrate nitrogen concentration ≤10 mg / L. If the effluent ammonia nitrogen in the pure membrane MBBR anoxic zone is <1.5 mg / L and COD is <40 mg / L, control the DO in the pure membrane MBBR aerobic zone to 1-2 mg / L. If the effluent ammonia nitrogen in the pure membrane MBBR anoxic zone is >1.5 mg / L or COD is >40 mg / L, control the DO in the pure membrane MBBR aerobic zone to 2-4 mg / L.

[0036] Furthermore, suspended carriers were added to both the anoxic and aerobic zones of the pure membrane MBBR, with a carrier loading rate greater than 50%. In the aerobic zone of the pure membrane MBBR, carrier attachment was achieved through aeration. The effective specific surface area of ​​the suspended carriers in the anoxic zone of the pure membrane MBBR was ≥800 m². 2 / m 3 The specific gravity is 1.01–1.05; the effective specific surface area of ​​the suspended carrier in the aerobic zone of the pure membrane MBBR is ≥800 m². 2 / m 3 The specific gravity is 0.94~0.97. The MLSS in the anoxic and aerobic regions of the pure membrane MBBR is <200mg / L, and the ORP in the anoxic region of the pure membrane MBBR is ≤-200mV.

[0037] Furthermore, the pure membrane MBBR is equipped with a stirrer in the anoxic zone, 5W / m 3 Tank volume ≤ stirring power density of stirrer ≤ 15W / m³ 3 Pool capacity.

[0038] Example 1:

[0039] A wastewater treatment plant has a designed treatment capacity of 40,000 m³. 3 The design influent TN is 70 mg / L / day, and the effluent TN is 15 mg / L. Upgrading is required to further control the effluent TN to below 10 mg / L. The project will be implemented by constructing a new post-denitrification unit, including a pure membrane MBBR anoxic zone and a pure membrane MBBR aerobic zone, with a total retention time of 1.5 hours and an effective specific surface area > 800 m². 2 / m 3The suspended carriers were all 50% filled, and the stirring power density in the anoxic zone of the pure membrane MBBR was 7.5 W / m³. 3 During the project's initial phase, with an added C / N ratio of 3-5, rapid biofilm formation was achieved on the carrier, resulting in a biofilm thickness of 218 μm, a relative abundance of denitrifying bacteria of 23.55%, and a denitrification load of 0.91 kgN / m³. 3 / d, biofilm formation is complete, C / N ratio decreases to 2-3. After acclimatization, biofilm thickness remains at 222 μm, relative abundance of denitrifying bacteria is 22.87%, and short-range denitrification loading is 0.63 kgN / m³. 3 / d, after short-cut denitrification acclimatization is completed, the system enters the anaerobic ammonia oxidation (ANOCO) cultivation stage. A portion of the wastewater from the wastewater treatment plant is introduced into the anoxic zone of the pure membrane MBBR, accounting for 15% of the total influent to the post-denitrification unit. The mixed ANOCO nitrogen level is 7.5 mg / L, and the C / N ratio is 1.5. The influent C / N ratio is controlled by adjusting the external carbon source dosage. The system operates at a C / N ratio of 2-3 for 4 hours, followed by a 2-hour cycle after stopping carbon source addition. The ANOCO load is gradually increased to 0.07 kgN / m³. 3 The anaerobic ammonia oxidation load was adjusted to a C / N ratio of 2-3 and run for 5 hours. Carbon source addition was stopped for 1 hour, and the cycle continued. Afterward, the anaerobic ammonia oxidation load was increased to 0.13 kgN / m³. 3 / d, changed to a C / N ratio of 2~3 throughout the day, the relative abundance of anaerobic ammonia oxidizing bacteria in the biofilm increased to 2.15%, and the anaerobic ammonia oxidation load was 0.43 kgN / m³. 3 / d, the biofilm thickness was maintained at 225μm, the anaerobic ammonia oxidation culture was completed, and stable operation began. During the stable operation phase, the effluent TN was ≤8mg / L, and the anaerobic ammonia oxidation denitrification rate reached more than 70%, saving 70% of carbon source compared with conventional deep denitrification processes.

[0040] Example 2:

[0041] A wastewater treatment plant has a designed treatment capacity of 20,000 m³. 3The design capacity is 80 mg / L for influent TN and 10 mg / L for effluent. The process flow is: pretreatment → activated sludge (AAO) → secondary sedimentation tank → denitrification filter → disinfection. The denitrification filter has an influent TN of approximately 15 mg / L and an effluent TN of 10 mg / L, resulting in a removal rate of approximately 5 mg / L. The C / N ratio is 5.5, and the carbon source cost is 0.12 yuan / ton of water. This project will be used to modify the denitrification filter into a pure membrane MBBR biological treatment tank. After carrier attachment, acclimatization, and debugging, the total nitrogen (TN) of the influent to the anoxic zone of the pure membrane MBBR is approximately 15 mg / L, and the effluent TN is controlled at 10 mg / L. The contribution rate of anaerobic ammonia oxidation (AAO) for nitrogen removal reaches 60%, and the carbon source cost per ton of water is reduced to 0.05 yuan / ton. Further, by reducing the carbon source dosage of the front-end activated sludge (AAO) and increasing the proportion of raw water in the pure membrane MBBR anoxic zone, the influent TN of the pure membrane MBBR anoxic zone is increased to 25 mg / L, and the effluent TN is controlled at 10 mg / L. At this point, the contribution rate of AAO for nitrogen removal is further increased to 65%, and the carbon source cost per ton of water is 0.12 yuan / ton. However, the carbon source cost of the front-end activated sludge (AAO) is reduced by 0.24 yuan / ton, resulting in an overall reduction of 0.12 yuan / ton compared to before the modification. Simultaneously, because some raw water directly enters the pure membrane MBBR anoxic zone for treatment, the front-end activated sludge (AAO) aeration rate is reduced by 11%, achieving energy saving and consumption reduction.

[0042] Those skilled in the art should recognize that the above embodiments are only used to illustrate this application and are not intended to limit this application. Any appropriate changes and variations made to the above embodiments within the essential spirit and scope of this application fall within the scope of protection claimed in this application.

Claims

1. A method for low-consumption, deep nitrogen removal based on MBBR (Medium-Medium-Density Bioreactor) denitrification-anaerobic ammonium oxidation, characterized in that... Includes the following steps: a. Carrier biofilm formation stage: The effluent from the biologically treated wastewater plant is introduced into the anoxic zone of the pure membrane MBBR. A carbon source is added to the anoxic zone to achieve suspended carrier biofilm formation and denitrifying bacteria growth and enrichment. The C / N ratio is 3-5. The effluent nitrate nitrogen concentration in the aerobic zone of the pure membrane MBBR after the anoxic zone is maintained at ≤10 mg / L until the biofilm thickness is >200 μm, the relative abundance of denitrifying bacteria is >20%, and the loading is greater than 0.8 kgN / m³. 3 / d, entering the short-cut denitrification acclimatization stage; the pollutant concentration in the effluent after biological treatment of the wastewater plant is 15~25mg / L; b. Short-cut denitrification acclimatization stage: Add carbon source to the anoxic zone of the pure membrane MBBR to adjust and control the C / N ratio to 2-3, and maintain the effluent nitrate nitrogen concentration in the aerobic zone of the pure membrane MBBR ≤10mg / L until the nitrite nitrogen ratio in the effluent nitrate nitrogen is >80%, the biofilm thickness is >200μm, the relative abundance of denitrifying bacteria is >20%, and the short-cut denitrification load is >0.6kgN / m³. 3 / d, biofilm acclimatization is complete, and the culture enters the anaerobic ammonia oxidation stage; c. Anaerobic ammonia oxidation cultivation stage: Municipal wastewater raw water and effluent from the wastewater treatment plant's biological treatment are introduced together into the anoxic zone of the pure membrane MBBR. The ammonia nitrogen concentration after mixing is controlled at 5-10 mg / L. Carbon sources are added to the anoxic zone of the pure membrane MBBR to provide nitrite for short-cut denitrification until the relative abundance of anaerobic ammonia oxidizing bacteria in the biofilm is >2% and the anaerobic ammonia oxidation load is greater than 0.4 kgN / m³. 3 / d, biofilm thickness >200μm, anaerobic ammonia oxidation culture completed, entered stable operation stage; d. Stable operation phase: The municipal sewage raw water and the effluent from the sewage treatment plant after biological treatment are introduced into the anoxic zone of the pure membrane MBBR. The ammonia nitrogen concentration after mixing is controlled at 5~10mg / L. A carbon source is added to the anoxic zone of the pure membrane MBBR to provide nitrogenous residue for short-cut denitrification. Stable anaerobic ammonia oxidation denitrification is achieved in the anoxic zone of the pure membrane MBBR.

2. The method for low-consumption deep nitrogen removal based on MBBR to achieve short-cut denitrification-anaerobic ammonium oxidation according to claim 1, characterized in that: After controlling the ammonia nitrogen concentration after mixing to 5-10 mg / L in step c, and considering the COD concentration of the municipal wastewater, the C / N ratio of the influent to the anoxic zone of the pure membrane MBBR is controlled by adjusting the carbon source dosage. Initially, the system is run at a C / N ratio of 2-3 for 4 hours, then the carbon source dosage is stopped for 2 hours, and the cycle continues until the anaerobic ammonia oxidation load exceeds 0.05 kgN / m³. 3 When the anaerobic ammonia oxidation load is greater than 0.1 kgN / m³, run the cycle for 5 hours with a C / N ratio of 2-3, then stop adding carbon source for 1 hour until the anaerobic ammonia oxidation load is greater than 0.1 kgN / m³. 3 When the biofilm contains anaerobic ammonia-oxidizing bacteria, it is operated at a C / N ratio of 2-3 throughout the day until the relative abundance of anaerobic ammonia-oxidizing bacteria in the biofilm is >2% and the anaerobic ammonia oxidation load is greater than 0.4 kgN / m³. 3 / d, biofilm thickness >200μm, anaerobic ammonia oxidation culture completed.

3. The method for low-consumption deep nitrogen removal based on MBBR to achieve short-cut denitrification-anaerobic ammonium oxidation according to claim 1, characterized in that: In step d, after controlling the ammonia nitrogen concentration after mixing to 5~10 mg / L, and in conjunction with the COD concentration of the municipal wastewater, the C / N ratio of the influent to the anoxic zone of the pure membrane MBBR is controlled to be 2~3 by adjusting the carbon source dosage. Stable anaerobic ammonia oxidation denitrification is achieved in the anoxic zone of the pure membrane MBBR, and the nitrate nitrogen concentration in the effluent of the aerobic zone of the pure membrane MBBR is kept ≤10 mg / L.

4. The method for low-consumption deep nitrogen removal based on MBBR to achieve short-cut denitrification-anaerobic ammonium oxidation according to claim 3, characterized in that: If the ammonia nitrogen in the aerobic zone of the pure membrane MBBR is <1.5 mg / L and the COD is less than 40 mg / L, the DO in the aerobic zone of the pure membrane MBBR should be controlled at 1~2 mg / L. If the ammonia nitrogen in the aerobic zone of the pure membrane MBBR is >1.5 mg / L or the COD is >40 mg / L, the DO in the aerobic zone of the pure membrane MBBR should be controlled at 2~4 mg / L.

5. The method for low-consumption deep nitrogen removal based on MBBR to achieve short-cut denitrification-anaerobic ammonium oxidation according to claim 1, characterized in that: Suspended carriers are added to both the anoxic zone and the aerobic zone of the pure membrane MBBR, with a filling rate of more than 50% for the suspended carriers; the aerobic zone of the pure membrane MBBR achieves biofilm formation through aeration.

6. The method for low-consumption deep nitrogen removal based on MBBR to achieve short-cut denitrification-anaerobic ammonium oxidation according to claim 5, characterized in that: The effective specific surface area of ​​the pure membrane MBBR anoxic zone suspension carrier is ≥800 m². 2 / m 3 The specific gravity is 1.01–1.05; the effective specific surface area of ​​the suspended carrier in the aerobic zone of the pure membrane MBBR is ≥800 m². 2 / m 3 Its specific gravity is 0.94~0.

97.

7. The method for low-consumption deep nitrogen removal based on MBBR to achieve short-cut denitrification-anaerobic ammonium oxidation according to claim 1, characterized in that: The MLSS in the anoxic and aerobic regions of the pure membrane MBBR is <200 mg / L, and the ORP in the anoxic region of the pure membrane MBBR is ≤-200 mV.

8. The method for low-consumption deep nitrogen removal based on MBBR to achieve short-cut denitrification-anaerobic ammonium oxidation according to claim 1, characterized in that: The anoxic zone of the pure membrane MBBR is equipped with a stirrer with a stirring power density of 5~15W / m³. 3 Pool capacity.

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