CN115043491A - A system and method for maximizing denitrification of urban sewage Anammox - Google Patents

Abstract

A system and a method for realizing maximization of Anammox denitrification of municipal sewage belong to the field of biological sewage treatment, and provide a reaction substrate NO for Anammox through three ways of mainstream short-cut nitrification, side-stream short-cut nitrification and short-cut denitrification ₂ ^‑ -N. Municipal sewage firstly enters an organic matter capture reactor to remove COD, and effluent flows into a main flow short-cut nitrification reactor to oxidize partial NH ₄ ⁺ N, followed by high NO ₂ ^‑ The side flow short-cut nitrified effluent of the-N enters an Anammox reactor together for removal, the effluent and municipal sewage enter the short-cut denitrifying Anammox reactor together, and the organic matters in the municipal sewage are utilized to carry out NO treatment in the nitrification and Anammox processes ₃ ^‑ Conversion of-N to NO ₂ ^‑ N, by Anammox with NH in municipal sewage ₄ ⁺ -N is removed in situ. The invention utilizes high NH of side stream ₄ ⁺ Stable and high-efficient NO production by short-cut nitrification and short-cut denitrification of-N wastewater ₂ ^‑ The characteristic of-N, only needs to control a small amount of NH in the municipal sewage ₄ ⁺ Oxidation of-N achieves efficient Anammox denitrification.

Description

A system and method for maximizing denitrification of urban sewage Anammox

technical field

The invention belongs to the technical field of sewage biological treatment, and more particularly, relates to a system and method for realizing the maximization of Anammox denitrification of urban sewage, and belongs to the technical field of sewage biological denitrification.

Background technique

Water eutrophication is an important pollution problem facing the world's water environment and needs to be solved urgently. Water eutrophication will lead to the death of a large number of aquatic organisms such as algae and fish in the water environment, and will cause the water body to turn black and smelly. At present, the deep denitrification and dephosphorization of urban domestic sewage has become one of the important ways to curb the eutrophication of water bodies. Traditional nitrification/denitrification denitrification processes have been widely used in sewage treatment plants worldwide. However, considering that the nitrification/denitrification process has considerable energy consumption and organic carbon requirements, it goes against the theme of today's green, energy-saving and sustainable economic model. As my country's sewage discharge standards become more stringent, it is undoubtedly the key direction of sewage treatment research at this stage to further explore new biological denitrification processes with sustainable development prospects, reducing the addition of carbon sources and the consumption of aeration volume. profound practical significance.

Anammox is a new type of autotrophic denitrification technology. Under anoxic conditions, anammox bacteria use NO ₂ ^- as an electron acceptor to convert NH ₄ ⁺ into N ₂ . The advantages of gas and organic carbon sources, low sludge yield, and high denitrification load have become a research hotspot in the field of sewage denitrification. At present, anammox technology has been successfully applied to sludge digestion liquid, landfill leachate, pharmaceutical wastewater, aquaculture wastewater and other high ammonia nitrogen wastewater treatment projects. However, for urban sewage, due to the low concentration of NH ₄ ⁺ -N, it is difficult to achieve stable NO ₂ ^- -N accumulation during the short-range nitrification process, and NO ₃ ^- -N will inevitably be generated during the operation process, leading to anammox. The process treatment effect is poor, and the total nitrogen concentration in the effluent is high.

In recent years, Chinese scholars have put forward the new technology of short-range denitrification for the first time, which provides a new method to break through the bottleneck that Anammox process is difficult to obtain NO ₂ ^- -N stably in urban sewage treatment. The key problem of the current mainstream Anammox process is that the contribution rate of Anammox is low. If the denitrification of urban sewage Anammox can be maximized and the consumption of aeration and carbon sources during the operation process can be greatly reduced, it will be more in line with the concept of green and sustainable development.

Based on this, the present invention, on the basis of the existing technology, innovates the deep denitrification process with Anammox as the core, uses side-stream short-path nitrification to assist and enhance the mainstream Anammox denitrification process, combines the mainstream short-path nitrification and short-path denitrification processes, The characteristics of short-range nitrification and short-range denitrification of NO ₂ ^- -N in high-flow NH ₄ ⁺ -N wastewater can maximize the denitrification of urban sewage Anammox and provide a new route for deep denitrification of urban sewage.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned defects of the prior art and provide a system and method for maximizing the denitrification of urban sewage Anammox, and set up a side flow process to supplement the NO ₂ ^- -N produced by short-range nitrification to the mainstream Anammox reactor The mainstream short-path nitrification and short-path denitrification processes also provide the substrate NO ₂ ^- -N for the Anammox reactor, and the innovative use of the composite process maximizes the supply of NO ₂ ^- -N for Anammox; on the other hand, through the final link setting The short-range denitrification is coupled with the anaerobic ammonia oxidation process to remove nitrogen at the bottom, so as to maximize the denitrification of urban sewage, and greatly improve the process stability and urban sewage treatment efficiency.

In order to solve the above technical problems, the present invention provides a system for maximizing the denitrification of urban sewage Anammox, comprising: a raw urban sewage tank (1), an organic matter capture reactor (2), a mainstream short-path nitrification reactor (3), Anammox reactor (4), short-path denitrification coupled anammox reactor (5), sludge anaerobic digestion liquid storage tank (6), side-flow short-path nitrification reactor (7); among them, urban sewage The sewage in the raw water tank (1) enters the organic matter capture reactor (2) to capture and remove COD; the effluent of the organic matter capture reactor (2) flows through the mainstream short-path nitrification reactor (3); the sludge anaerobic digestion solution storage tank The sludge digested liquid in (6) enters the side-flow short-path nitrification reactor (6), and performs short-path nitrification to produce NO ₂ ^- -N; The effluent is transported to the anammox reactor (4) for nitrogen removal, and finally the effluent of the anammox reactor (4) and the municipal sewage together enter the short-path denitrification coupled anammox reactor (5) for nitrogen removal. Deep denitrification.

The urban sewage raw water tank (1) is a closed box body, and is provided with an overflow pipe I (1.1) and a vent pipe I (1.2);

The organic matter capture reactor (2) is provided with a stirrer I (2.1), an aeration head I (2.2), a gas flow meter I (2.3), an air pump I (2.4), and an inlet pump I (2.5);

The mainstream short-path nitrification reactor (3) is provided with a stirrer II (3.1), a DO/pH online measuring instrument I (3.2), an aeration head II (3.3), a gas flow meter II (3.4), an air pump II (3.5 ), inlet water pump II (3.6), sampling port I (3.7);

The anammox reactor (4) is provided with a sampling port II (4.1), an inlet pump III (4.2), a water outlet (4.3), a three-phase separator (4.4), a gas collecting bottle (4.5), and an inlet pump IV(4.6);

The short-path denitrification coupled anammox reactor (5) is provided with a stirrer III (5.1), a DO/pH online measuring instrument II (5.2), a sampling port III (5.3), an inlet pump V (5.4), an inlet Water pump VI (5.5);

The sludge anaerobic digestion liquid storage tank (6) is provided with an overflow pipe I (6.1) and a vent pipe I (6.2);

The side-flow short-path nitrification reactor (7) is provided with a stirrer IV (7.1), a DO/pH online measuring instrument III (7.2), an aeration head III (7.3), a gas flow meter III (7.4), an air pump III ( 7.5), inlet water pump VII (7.6), sampling port IV (7.7). A method for realizing the maximization of denitrification of urban sewage Anammox according to claim 1, it is characterized in that, specifically comprises the following steps:

1) Start-up system: Add the sludge with short-path nitrification activity to the mainstream short-path nitrification reactor (3) and the side-flow short-path nitrification reactor (6) respectively, so that the sludge concentration in the reactor is MLSS=3.0～4.0g /L; put the sludge with anammox activity into the anammox reactor (4), so that the sludge concentration in the reactor is MLSS=5.0～10.0g/L; will have high NO ₂ ^- - The N-accumulated short-path denitrification sludge and anammox activated sludge are added to the short-path denitrification coupled anammox reactor (5) according to the mass concentration ratio of 1:1 to 3, so that the sludge in the reactor Concentration MLSS=4～6.0g/L; the accumulation rate of NO ₂ ^- -N in the short-path nitrification sludge is greater than 90%, the activity of the anammox sludge is greater than 20mg N/g VSS/h, and the short-path denitrification sludge NO ₃ The ^- -N to NO ₂ ^- -N conversion rate is greater than 80%.

2) The adjustment operation at runtime is as follows

The urban sewage is introduced into the organic matter capture reactor, and the dissolved oxygen DO concentration of the reactor is controlled to be 1.0-4.0 mg/L, the hydraulic retention time is 2-6 h, the sludge retention time is 2-6 d, and the effluent COD concentration is 30-60 mg/L;

The effluent of the organic matter capture reactor is introduced into the mainstream short-path nitrification reactor, the dissolved oxygen concentration is controlled to be 0.1-0.5mg/L, and the sludge residence time is 8-15d;

The supernatant of sludge anaerobic digestion is introduced into the side-flow short-path nitrification reactor, the dissolved oxygen concentration is controlled to be 0.5-1.5mg/L, the sludge residence time is 8-20d, the NH ₄ ⁺ -N removal rate is greater than 90%, the NO ₂ ^- -N accumulation rate is greater than 80%;

The effluent of the main stream short-path nitrification reactor and the effluent of the side-flow short-path nitrification reactor are sent into the anammox reactor together, and the mass concentration ratio of NO ₂ ^- -N and NH ₄ ⁺ -N in the mixed influent is controlled to be 1.2 to 1.4, and the reactor The effluent NO ₂ ^- -N concentration is less than 3mg/L;

The anaerobic ammonium oxidation reactor effluent and urban sewage enter the short-range denitrification coupled anaerobic ammonium oxidation reactor together, and the mass concentration ratio of NO ₃ ^- -N and NH ₄ ⁺ -N in the mixed influent is controlled to be 1.2 to 1.5, and the COD and The NO ₃ ^- -N mass concentration ratio is 2.8-4.5, the sludge residence time is 8-20 d, and the particle size of the sludge discharged from the reactor is flocculent sludge less than 0.2 mm.

During the operation of the anammox reactor, when the mass concentration ratio of NO ₂ ^- -N and NH ₄ ⁺ -N in the influent water is less than 1.2, the removal rate of NH ₄ ⁺ -N in the mainstream short-path nitrification reactor is improved. When it is greater than 1.4, the removal rate of NH ₄ ⁺ -N in the mainstream short-path nitrification reactor is reduced;

During the operation of the anammox reactor, when the NO ₂ ^- -N concentration in the effluent is greater than 3 mg/L, the hydraulic retention time is appropriately extended;

In the operation process of the short-range denitrification coupled anammox reactor, when the mass concentration ratio of COD and NO ₃ ^- -N in the influent water is greater than 4.5, the effluent of the organic matter capture reactor is introduced to reduce COD and NO in the range of 2.8 to 4.5. ₃ ^- -N mass concentration ratio.

In summary, a system and method for maximizing the denitrification of urban sewage Anammox is provided. The process of treating urban sewage is as follows: the sewage in the urban sewage raw water tank enters the organic matter capture reactor to capture and remove COD; the organic matter capture reaction The effluent flows through the mainstream short-path nitrification reactor; the sludge digested liquid in the sludge anaerobic digestion solution storage tank enters the side-flow short-path nitrification reactor for short-path nitrification to produce NO ₂ ^- -N; the effluent of the side-flow short-path nitrification reactor Together with the effluent of the mainstream short-path nitrification reactor, it is transported to the anammox reactor for nitrogen removal, and finally the effluent of the anammox reactor and municipal sewage enter the short-path denitrification coupled anammox reactor for deep denitrification. .

Therefore, the present invention provides a system and method for maximizing the denitrification of urban sewage Anammox, which has the following advantages:

1. Utilize the lateral flow sludge anaerobic digestion liquid for short-range nitrification of NO ₂ ^- -N to provide partial substrates for mainstream Anammox, reduce the oxidation ratio of NH ₄ ⁺ -N in urban sewage, thereby reducing NO ₃ in the short-range nitrification process of urban sewage ^- Generation of -N;

2. The present invention can maximize the autotrophic denitrification ratio of the Anammox process in urban sewage, greatly reduce the aeration amount and carbon source consumption during operation, save energy, and also conform to the concept of sustainable development, and is suitable for engineering popularization and application;

3. On the other hand, by setting up short-range denitrification, the NO ₃ ^- -N produced by the nitrification process and the anammox reaction process is converted into NO ₂ ^- -N, and then removed through the Anammox pathway to further improve the denitrification ratio of Anammox, The total nitrogen concentration in the effluent can be greatly reduced, which can realize the ultra-deep removal of nitrogen in urban sewage, and can meet the stricter requirements for nitrogen in urban sewage treatment in the future.

Description of drawings

The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of the exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the exemplary embodiments of the present invention. same parts.

FIG. 1 is a schematic diagram of a system flow diagram of the present invention for maximizing the denitrification of urban sewage Anammox.

Figure 2 is a diagram of the conversion of C and N elements in the process flow of the method.

AOB: short-range nitrifying bacteria; Anammox: anaerobic ammonium oxidizing bacteria; NH ₄ ⁺ : ammonia nitrogen; NO ₂ ^- : nitrite nitrogen; NO ₃ ^- : nitrate nitrogen; COD: chemical oxygen demand; MW: mainstream urban sewage; DL: sludge anaerobic digestion effluent; HRAS: organic matter capture reactor; PDA: short-path denitrification coupled with anammox reactor; PN: short-path nitrification reactor.

Description of reference numbers:

In the figure, 1 is the urban sewage raw water tank, 2 is the organic matter capture reactor, 3 is the mainstream short-path nitrification reactor, 4 is the anammox reactor, 5 is the short-path denitrification coupled anammox reactor, and 6 is the sludge Anaerobic digestion liquid storage tank, 7 is the side-flow short-range nitrification reactor; 1.1 is the overflow pipe I, 1.2 is the vent pipe I; 2.1 is the agitator I, 2.2 is the aeration head I, 2.3 is the gas flow meter I, 2.4 is the air pump I, 2.5 is the inlet water pump I; 3.1 is the agitator II, 3.2 is the DO/pH online measuring instrument I, 3.3 is the aeration head II, 3.4 is the gas flow meter II, 3.5 is the air pump II, and 3.6 is the inlet water pump II and 3.7 are sampling port I; 4.1 is sampling port II, 4.2 is inlet pump III, 4.3 is water outlet, 4.4 is three-phase separator, 4.5 is gas cylinder, 4.6 is inlet pump IV; 5.1 is agitator III, 5.2 is DO/pH online measuring instrument II, 5.3 is sampling port III, 5.4 is inlet pump V, 5.5 is inlet pump VI; 6.1 is overflow pipe II, 6.2 is venting pipe II, 7.1 is agitator IV, and 7.2 is DO/pH online measuring instrument III, 7.3 is the aeration head III, 7.4 is the gas flow meter III, 7.5 is the air pump III, 7.6 is the inlet pump VII, and 7.7 is the sampling port IV.

Detailed ways

The above scheme will be further described below in conjunction with specific embodiments, and preferred embodiments of the present invention are described in detail as follows:

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments: as shown in Figure 1, a system and method for realizing the maximization of urban sewage Anammox denitrification, comprising:

The sewage in the urban sewage raw water tank enters the organic matter capture reactor for COD capture and removal; the effluent of the organic matter capture reactor flows through the mainstream short-path nitrification reactor; the sludge digested liquid in the sludge anaerobic digestion liquid storage tank enters the side-flow short-path The nitrification reactor is used for short-path nitrification to produce NO ₂ ^- -N; the effluent of the side-flow short-path nitrification reactor and the effluent of the mainstream short-path nitrification reactor are transported to the anammox reactor for nitrogen removal, and finally the anammox reaction The effluent and urban sewage enter the short-range denitrification coupled anammox reactor together for deep denitrification.

The specific test water is taken from the domestic sewage of a certain community, and its water quality is as follows: COD concentration is 348.6mg/L; NH ₄ ⁺ -N concentration is 52.8mg/L, NO ₂ ^- -N≤0.5mg/L, NO ₃ ^- -N ≤0.5mg/L. The water quality of anaerobic sludge digestion solution is as follows: NH ₄ ⁺ -N concentration is 439.6mg/L, COD concentration is 338.8mg/L The test system is shown in Figure 1, the effective volume of the organic matter capture reactor is 8L, and the mainstream short-path nitrification reactor is The effective volume is 12L, the effective volume of the side-stream short-path nitrification reactor is 1L, the effective volume of the anammox reactor is 3L, and the effective volume of the short-path denitrification coupled anammox reactor is 5L. The aeration device is installed at the bottom of the short-path nitrification reactor and the organic matter capture reactor, and the constant dissolved oxygen can be controlled by adjusting the flow meter and DO online feedback.

The specific operation is as follows:

1. Start-up system: Add the sludge with short-path nitrification activity to the mainstream short-path nitrification reactor and the side-flow short-path nitrification reactor respectively, so that the sludge concentration in the reactor is MLSS=3.0g/L; The oxidatively active sludge is fed into the anammox reactor, so that the sludge concentration in the reactor is MLSS=6.0g/L; the short-range denitrification sludge with high NO ₂ ^- -N accumulation and anammox The activated sludge was added to the short-range denitrification coupled anammox reactor at a mass concentration ratio of 1:3, so that the sludge concentration in the reactor was MLSS=4.0g/L. The accumulation rate of NO ₂ ^- -N in the short-range nitrification sludge reaction process is greater than 90%, and the conversion rate of NO ₃ ^- -N to NO ₂ ^- -N during the short-range denitrification sludge reaction process is greater than 80%.

2. The adjustment operation at runtime is as follows:

Urban sewage (48L/d) was introduced into the organic matter capture reactor. When the dissolved oxygen DO concentration in the reactor was 1.0-1.2mg/L, the hydraulic retention time was 4h, and the sludge retention time was 3d, the average NH ₄ ⁺ -N concentration in the effluent was obtained. The value is 49.3mg/L, and the average COD concentration is 42.6mg/L;

The effluent of the organic matter capture reactor is introduced into the mainstream short-path nitrification reactor. When the dissolved oxygen concentration is about 0.3mg/L, the sludge residence time is 12d, 8 cycles are run every day (aerobic 2h per cycle), and the drainage ratio is 50%. , the average concentrations of NH ₄ ⁺ -N, NO ₃ ^- -N and NO ₂ ^- -N in the effluent are 18.3mg/L, 12.4mg/L and 17.2mg/L, respectively;

The supernatant of sludge anaerobic digestion (1L/d) was introduced into the side-flow short-path nitrification reactor. When the dissolved oxygen concentration was about 1.0mg/L, the sludge residence time was 16d, and it ran for 2 cycles per day (each cycle aerobic 1h), when the drainage ratio is 50%, the average concentration of NH ₄ ⁺ -N in the effluent is 38.8mg/L, the average concentration of NO ₂ ^- -N is 345.6mg/L, and the average concentration of NO ₃ ^- -N is 35.5mg /L;

The main stream short-path nitrification reactor effluent (48L/d) and the side-stream short-path nitrification reactor effluent (1.0L/d) were entered into the anammox reactor together, the hydraulic retention time was 1.5h, and the reactor effluent NO ₂ ^- - The average value of N concentration is 0.8mg/L, the average value of NH ₄ ⁺ -N concentration is 1.2mg/L, and the average value of NO ₃ ^- -N concentration is 17.5mg/L;

The effluent of the anammox reactor and the municipal sewage (11L/d) enter the short-range denitrification coupled anammox reactor together. The hydraulic retention time is 2h, and the flocculent sludge (particle size less than 0.2 h) is discharged from the reactor. mm) under the condition that the sludge residence time is controlled to be 16d, the average concentration of NH ₄ ⁺ -N in the effluent is 1.3mg/L, the average concentration of NO ₃ ^- -N is 3.4mg/L, and the concentration of NO ₂ ^- -N is almost 0mg /L.

After long-term stable operation, the final effluent COD concentration of the combined system is 46.7 mg/L, the TN concentration is 4.7 mg/L, and the total nitrogen removal rate in urban sewage is as high as 91.0%.

Claims (2)

1. a system that realizes urban sewage Anammox denitrification maximization is characterized in that: be provided with urban sewage raw water tank (1), organic matter capture reactor (2), mainstream short-range nitrification reactor (3), anaerobic ammonia oxidation A reactor (4), a short-path denitrification coupled anammox reactor (5), a sludge anaerobic digestion solution storage tank (6), and a side-stream short-path nitrification reactor (7); wherein, the urban sewage raw water tank (1) ) into the organic matter capture reactor (2) to capture and remove COD; the effluent from the organic matter capture reactor (2) flows through the mainstream short-range nitrification reactor (3); the sludge anaerobic digestion solution storage tank (6) The sludge digested liquid enters the side-flow short-path nitrification reactor (6) for short-path nitrification to produce NO ₂ ^- -N; the effluent of the side-flow short-path nitrification reactor (6) is transported together with the effluent of the mainstream short-path nitrification reactor (3) Nitrogen removal is carried out in the anammox reactor (4), and finally the effluent of the anammox reactor (4) and the municipal sewage enter the short-path denitrification coupled anammox reactor (5) together for deep denitrification; The urban sewage raw water tank (1) is a closed box body, and is provided with an overflow pipe I (1.1) and a vent pipe I (1.2); The organic matter capture reactor (2) is provided with a stirrer I (2.1), an aeration head I (2.2), a gas flow meter I (2.3), an air pump I (2.4), and an inlet pump I (2.5); The mainstream short-path nitrification reactor (3) is provided with a stirrer II (3.1), a DO/pH online measuring instrument I (3.2), an aeration head II (3.3), a gas flow meter II (3.4), an air pump II (3.5 ), inlet water pump II (3.6), sampling port I (3.7); The anammox reactor (4) is provided with a sampling port II (4.1), an inlet pump III (4.2), a water outlet (4.3), a three-phase separator (4.4), a gas collecting bottle (4.5), and an inlet pump IV(4.6); The short-path denitrification coupled anammox reactor (5) is provided with a stirrer III (5.1), a DO/pH online measuring instrument II (5.2), a sampling port III (5.3), an inlet pump V (5.4), an inlet Water pump VI (5.5); The sludge anaerobic digestion liquid storage tank (6) is provided with an overflow pipe I (6.1) and a vent pipe I (6.2); The side-flow short-path nitrification reactor (7) is provided with a stirrer IV (7.1), a DO/pH online measuring instrument III (7.2), an aeration head III (7.3), a gas flow meter III (7.4), an air pump III ( 7.5), inlet water pump VII (7.6), sampling port IV (7.7). 2. a method for realizing the maximization of urban sewage Anammox denitrification by the system according to claim 1, is characterized by comprising the following steps: 1) Start-up system: Add the sludge with short-path nitrification activity to the mainstream short-path nitrification reactor and the side-flow short-path nitrification reactor respectively, so that the sludge concentration in the reactor is MLSS=3.0～4.0g/L; The sludge with oxyammonium oxidation activity is added to the anammox reactor, so that the sludge concentration in the reactor is MLSS=5.0～10.0g/L; The ratio of 1:1-3 is added to the short-path denitrification coupled anammox reactor, so that the sludge concentration in the reactor is MLSS=4-6.0g/L; the short-path nitrification sludge reaction process NO ₂ ^- - The N accumulation rate is greater than 90%, and the conversion rate of NO ₃ ^- -N to NO ₂ ^- -N in the short-range denitrification sludge reaction process is greater than 80%; 2) The adjustment operation at runtime is as follows The urban sewage is introduced into the organic matter capture reactor, and the dissolved oxygen DO concentration of the reactor is controlled to be 1.0-4.0 mg/L, the hydraulic retention time is 2-6 h, the sludge retention time is 2-6 d, and the effluent COD concentration is 30-60 mg/L; The effluent of the organic matter capture reactor is introduced into the mainstream short-path nitrification reactor, the dissolved oxygen concentration is controlled to be 0.1-0.5mg/L, and the sludge residence time is 8-15d; The supernatant of sludge anaerobic digestion is introduced into the side-flow short-path nitrification reactor, the dissolved oxygen concentration is controlled to be 0.5-1.5mg/L, the sludge residence time is 8-20d, the NH ₄ ⁺ -N removal rate is greater than 90%, the NO ₂ ^- -N accumulation rate is greater than 80%; The effluent of the main stream short-path nitrification reactor and the effluent of the side-flow short-path nitrification reactor are sent into the anammox reactor together, and the mass concentration ratio of NO ₂ ^- -N and NH ₄ ⁺ -N in the mixed influent is controlled to be 1.2 to 1.4, and the reactor The effluent NO ₂ ^- -N concentration is less than 3mg/L; The anaerobic ammonium oxidation reactor effluent and urban sewage enter the short-range denitrification coupled anaerobic ammonium oxidation reactor together, and the mass concentration ratio of NO ₃ ^- -N and NH ₄ ⁺ -N in the mixed influent is controlled to be 1.2 to 1.5, and the COD and The NO ₃ ^- -N mass concentration ratio is 2.8 to 4.5, the sludge residence time is 8 to 20 d, and the particle size of the sludge discharged from the reactor is flocculent sludge less than 0.2 mm; During the operation of the anammox reactor, when the mass concentration ratio of NO ₂ ^- -N and NH ₄ ⁺ -N in the influent water is less than 1.2, the removal rate of NH ₄ ⁺ -N in the mainstream short-path nitrification reactor is improved. When it is greater than 1.4, the removal rate of NH ₄ ⁺ -N in the mainstream short-path nitrification reactor is reduced; During the operation of the anammox reactor, when the NO ₂ ^- -N concentration in the effluent is greater than 3 mg/L, the hydraulic retention time is appropriately extended; In the operation process of the short-range denitrification coupled anammox reactor, when the mass concentration ratio of COD and NO ₃ ^- -N in the influent water is greater than 4.5, the effluent of the organic matter capture reactor is introduced to reduce COD and NO in the range of 2.8 to 4.5. ₃ ^- -N mass concentration ratio.

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