A method for achieving long-term stable short-range nitrification and denitrification phosphorus removal based on sludge side stream treatment

Abstract

The present invention discloses a method for achieving long-term and stable short-term nitrification, denitrification and phosphorus removal based on sludge side stream treatment, which belongs to the field of biological treatment of sewage. After the sewage in the reactor completes the short-term nitrification process, denitrification process, phosphorus removal process and carbon removal process, the activated sludge is divided into three directions, one part is discharged to maintain the sludge age, the other part continues to undergo the denitrification and phosphorus removal process in the reactor, and a small part of the sludge with excellent denitrification and phosphorus removal performance is retained and returned to a separate storage tank. In the later stage of operation, when the high concentration of nitrite nitrogen accumulates and causes the cell activity in the activated sludge to be damaged, the activated sludge retained in the early stage is returned to the reactor, thereby enhancing the denitrification and phosphorus removal performance of the sludge and achieving efficient and stable denitrification and phosphorus removal. The present invention realizes the synchronous and deep removal of nitrogen and phosphorus in sewage, is suitable for automated operation, and is convenient for realizing precise control and optimized management of the process.

Description

Technical Field

[0001] The present invention belongs to the field of biological sewage treatment, relates to biological denitrification and phosphorus removal of municipal sewage, and specifically relates to a method for achieving long-term stable short-range nitrification and denitrification phosphorus removal based on sludge side stream treatment. Background Art

[0002] Currently, most wastewater treatment plants use the A² / O process, which treats municipal wastewater through a complete nitrification and denitrification process. However, ensuring effluent meets standards requires extensive aeration and carbon sources, significantly increasing operating costs. Furthermore, while total nitrogen levels in wastewater after secondary treatment meet standards, phosphorus removal often requires chemical methods, further increasing costs. Coupled with increasingly stringent emission standards, deep denitrification and phosphorus removal have become a major challenge. Traditional biological denitrification and phosphorus removal processes suffer from slow proliferation of nitrifying bacteria, long hydraulic retention times, and low treatment efficiency. Especially for municipal wastewater with a low carbon / nitrogen ratio, the addition of an external carbon source increases capital and operating costs. Therefore, the development of efficient and energy-saving denitrification and phosphorus removal processes is of great significance to the wastewater treatment industry.

[0003] Traditional, integrated nitrification and denitrification processes face challenges in the application of municipal wastewater treatment. While effective, these traditional processes are plagued by high energy consumption, large sludge production, and high greenhouse gas emissions. In recent years, new technologies such as denitrification and denitrification have attracted widespread attention. These technologies have shown great potential in reducing energy consumption, sludge production, and greenhouse gas production. In particular, denitrification-coupled denitrification and phosphorus removal, by more efficiently utilizing carbon and nitrogen sources in municipal wastewater, significantly reduces aeration energy and organic carbon sources while also reducing sludge production. Therefore, this technology is considered a highly promising biological denitrification technology for advanced treatment of low-carbon-nitrogen ratio wastewater. Denitrification-coupled denitrification and phosphorus removal not only improves wastewater treatment efficiency but also effectively reduces energy consumption and sludge production during the treatment process, meeting the sustainable development goals of modern wastewater treatment. However, the accumulation of nitrite nitrogen generated during the denitrification process can be toxic to microorganisms, leading to "phosphate solubilization" and impairing phosphorus removal effectiveness. Therefore, the cytotoxic effect caused by the accumulation of high-concentration nitrite nitrogen is a bottleneck problem that needs to be solved urgently to achieve stable and efficient operation of the short-range nitrification and denitrification phosphorus removal process. Summary of the Invention

[0004] In order to solve the problem that the high concentration of nitrite nitrogen accumulated in the short-term nitrification of sewage treatment inhibits the phosphorus absorption capacity of the sludge, resulting in substandard phosphorus in the effluent, the present invention proposes a method for achieving long-term and stable short-term nitrification and denitrification phosphorus removal based on sludge side stream treatment, thereby achieving stable and efficient denitrification and phosphorus removal in sewage.

[0005] A method for achieving long-term stable short-range nitrification and denitrification phosphorus removal based on sludge side stream treatment. The specific process is as follows:

[0006] Phase 1: Construction of a short-cut nitrification and denitrification phosphorus removal system based on sludge side stream treatment;

[0007] The main body of the short-range nitrification, denitrification and phosphorus removal system is a reactor. The water inlet valve of the reactor is connected to the water inlet peristaltic pump, and the sewage is input into the reactor through the water inlet peristaltic pump; the drain valve on the side of the reactor and the mud discharge valve at the bottom are connected to the drainage peristaltic pump and the mud discharge peristaltic pump respectively, and the treated sewage is discharged into the drainage tank by the drainage peristaltic pump, and the treated sludge is discharged into the mud discharge tank and the mud storage tank respectively by the mud discharge peristaltic pump; an aeration head is installed at the bottom of the reactor, and oxygen is transported to the aeration head through the air inlet valve and then released into the reactor; an agitator is installed on the top of the reactor, and the stirring paddle extends into the sewage;

[0008] Furthermore, the DO and pH values ​​of the wastewater in the reactor were monitored by a DO sensor and a pH sensor.

[0009] Phase 2: System startup phase;

[0010] In step 201 , sewage is pumped into the main reactor through an inlet peristaltic pump to make the MLSS (mixed liquor suspended solids) of the activated sludge in the reactor 3000-3500 mg / L.

[0011] Step 202, acclimatizing the sewage in the reactor into sludge using oxygen as an electron acceptor for phosphorus removal in an anaerobic-aerobic operation mode, specifically:

[0012] Anaerobic stirring was performed for 120 min while water was being introduced, and then the reactor was aerated aerobically for 300 min, and finally settled for 30 min, drained for 10 min, with a drainage ratio of 50%, and left idle for 20 min after drainage;

[0013] Under anaerobic stirring conditions, polyphosphate-accumulating bacteria (PAOs and DPAOs), polyglycogen-accumulating bacteria (GAOs) and denitrifying polyglycogen-accumulating bacteria (DGAOs) absorb organic carbon sources in sewage and synthesize internal carbon sources PHA (PolyHydroxyAlkanoates) and store them in their bodies. At the same time, polyphosphate-accumulating bacteria will release phosphate particles in their bodies into the water under anaerobic conditions.

[0014] During aerobic aeration, the dissolved oxygen in the reactor was controlled at 2.0 ± 0.3 mg / L by a gas rotor flowmeter;

[0015] Step 203: Run three cycles per day in an anaerobic-aerobic mode. When the indicators meet the requirements and remain stable for 15 days, it indicates that the enrichment and domestication of polyphosphate bacteria using oxygen as an electron acceptor is complete, and enter the next stage;

[0016] The indicators include: NH4 in the effluent of the reactor + -N is 2-4 mg / L, NO3 - -N is 0-0.5mg / L, NO2 - -N is 0-0.5 mg / L, PO4 3- -P is 0-0.5 mg / L.

[0017] The third stage: sewage stabilization treatment stage;

[0018] Step 301, acclimatizing the short-cut nitrification and denitrification phosphorus removal sludge in an anaerobic-anoxic-aerobic operation mode, specifically as follows:

[0019] The sewage enters the reactor through the water inlet peristaltic pump and is anaerobically stirred for 120 minutes while the water is entering; then it is anaerobically stirred for 180 minutes, and at the initial stage of anoxic conditions, the required amount of sodium nitrite is calculated in accordance with the effective volume of the reactor, and a prepared 100 mg / L high-concentration sodium nitrite solution is added to simulate the accumulation of nitrite nitrogen in the sewage in the reactor to be 10 mg / L, and the sludge is acclimated to denitrification and phosphorus removal using nitrite as an electron acceptor; aerobic aeration is carried out for 120 minutes, and the dissolved oxygen in the reactor is controlled at 2 mg / L; then it is settled for 30 minutes, drained for 10 minutes, with a drainage ratio of 50%, and left idle for 20 minutes after drainage, with three cycles per day.

[0020] Step 302: When the system indicators meet the requirements and remain stable, the sludge in the reactor is discharged into the sludge discharge box, and the MLSS of the sludge in the reactor is maintained at 3500±200 mg / L. At the same time, 20% of the sludge in the effective volume of the reactor is discharged into the sludge storage box for standby use. The sludge age in the reactor is controlled at 20 to 25 days.

[0021] The indicators are: NH4 in the system outlet water + -N concentration is lower than 5 mg / L, the nitrite nitrogen accumulation rate reaches more than 80%, the total nitrogen removal rate reaches more than 50%, and the total phosphorus removal rate reaches more than 80%.

[0022] The fourth stage: based on the side-flow treatment to eliminate the toxicity of nitrite nitrogen accumulation;

[0023] Sewage enters the reactor via an inlet peristaltic pump, and anaerobic agitation begins simultaneously with water inflow, lasting 120 minutes. Prior to anoxic agitation, a 100 mg / L high-concentration sodium nitrite solution is added to the reactor, simulating short-term nitrification and producing high-concentration nitrite-nitrogen accumulation. During the anoxic period, nitrite-nitrogen accumulation in the reactor is maintained at 25 mg / L. Anoxic agitation is continued for 180 minutes, followed by aerobic aeration for 120 minutes. Dissolved oxygen in the reactor is controlled at 2.0 mg / L using a gas rotor flowmeter. The reactor then settles for 30 minutes, drains for 10 minutes, and is idle for 20 minutes after drainage, before the next cycle begins. Anaerobic agitation, anoxic agitation, aerobic aeration, sedimentation, drainage, and idle time are repeated three times daily.

[0024] After 60 days of operation, observe the water quality. If PO4 3- -P was higher than 2 mg / L for 7 consecutive days, indicating that the activated sludge had been subjected to toxic stress from nitrite nitrogen. At this time, the sludge in the sludge storage tank was added to the reactor at a ratio of 20% of the effective volume of the reactor, and the operation was continued. After a period of time, the phosphorus removal rate recovered to more than 80%.

[0025] The present invention has the following advantages:

[0026] 1) Easy-to-operate SBR reactor: The present invention adopts a sequencing batch reactor (SBR), which has the characteristics of easy operation, stable operation, and excellent precipitation effect. It is suitable for automated operation and facilitates precise control and optimized management of the process.

[0027] 2) Innovative denitrification and phosphorus removal technology: This invention introduces denitrification and phosphorus removal technology into the short-range nitrification process, fully leveraging its "one carbon, two uses" advantage. It effectively solves problems such as underutilized organic carbon sources, high nitrate nitrogen content in the effluent, and inability to remove phosphorus, achieving the simultaneous and deep removal of nitrogen and phosphorus in municipal wastewater.

[0028] 3) Highly efficient functional bacteria reserve: Under good operating conditions, the stored activated sludge contains a large number of highly functional denitrification and phosphorus removal bacteria. These functional bacteria can effectively alleviate the toxic effects of high nitrite nitrogen accumulation on the activated sludge during the short-range nitrification process, maintaining the system's efficient denitrification and phosphorus removal performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the device structure for achieving long-term short-term nitrification, denitrification and phosphorus removal for sludge side treatment.

[0030] In the picture:

[0031] 1- Municipal sewage raw water, 2- Short-range nitrification and denitrification sequencing batch reactor, 2.1- Water inlet peristaltic pump, 2.2- Water inlet valve, 2.3- SBR reactor, 2.4- Agitator, 2.5- Stirring paddle, 2.6- DO sensor, 2.7- pH sensor, 2.8- DO / pH meter, 2.9- Drain valve, 2.10- Mud discharge valve, 2.11- Aeration head, 2.12- Gas flow meter, 2.13- Air inlet valve, 2.14- Air pump, 2.15- Mud discharge peristaltic pump, 3- Mud discharge tank, 4- Mud storage tank; 5- Drain tank. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] The present invention proposes a new process for stable short-term nitrification, denitrification and phosphorus removal using sidestream sludge treatment. Short-term nitrification coupled with denitrification and phosphorus removal. After the activated sludge completes the short-term nitrification, denitrification, phosphorus removal and carbon removal processes, the activated sludge is divided into three directions: one portion is discharged to maintain the sludge age, the other portion continues to undergo denitrification and phosphorus removal in the reactor, and a small portion of sludge with excellent denitrification and phosphorus removal performance is retained and returned to a separate storage tank. In the later stages of operation, when high concentrations of nitrite nitrogen accumulate and damage the cell activity in the activated sludge, this portion of activated sludge retained in the early stages is returned to the beginning of the biological tank, thereby enhancing the denitrification and phosphorus removal performance of the sludge and achieving efficient and stable denitrification and phosphorus removal.

[0034] The present invention provides a method for achieving long-term, stable, and short-term nitrification and denitrification phosphorus removal using sludge sidestream treatment. By using a short-term nitrification and denitrification phosphorus removal process, sludge with good short-term nitrification and denitrification phosphorus removal efficiency is retained, allowing for timely replenishment of sludge whose performance deteriorates due to high nitrite nitrogen stress, thereby achieving long-term, stable, and efficient short-term nitrification and denitrification phosphorus removal. This method has the advantages of being green, economical, and easy to operate.

[0035] First, municipal sewage is pumped into the main reactor through a peristaltic pump. Under anaerobic stirring conditions, functional bacteria such as polyphosphate bacteria (PAOs and DPAOs), polyglycogenotrophs (GAOs) and denitrifying polyglycogenotrophs (DGAOs) will absorb the organic carbon source in the sewage and synthesize the internal carbon source PHA (PolyHydroxyAlkanoates) and store it in the body. At the same time, polyphosphate bacteria will release the phosphate particles in the body into the water body under anaerobic conditions, and the organic matter in the municipal sewage will be stored as an internal carbon source.

[0036] Set up intermittent aeration, and use time-controlled aeration and stop to achieve synchronous short-term nitrification, denitrification and phosphorus removal. Nitrification occurs during aeration, and when there is no aeration, the environment is converted to anoxic and denitrification and phosphorus removal is carried out.

[0037] Finally, part of the sludge is discharged, part is stored in the sludge side device for standby use, and the remaining part undergoes the main reaction in the reactor.

[0038] The present invention does not require an external organic carbon source, intermittent aeration can reduce the aeration volume, and synchronous deep denitrification and phosphorus removal are achieved through synchronous short-range nitrification and denitrification. The sludge side stream treatment can enhance the phosphorus removal effect and achieve stable denitrification and phosphorus removal in sewage.

[0039] like Figure 1 As shown, the device of the municipal sewage short-cut nitrification and denitrification phosphorus removal process includes a municipal sewage raw water tank (1), a short-cut nitrification and denitrification phosphorus removal reactor (2), a sludge discharge tank (3), a sludge storage tank (4), and a drainage tank (5). The actual domestic sewage is connected to the short-range nitrification, denitrification and phosphorus removal reactor (2) through an inlet peristaltic pump (2.1); the short-range nitrification, denitrification and phosphorus removal reactor (2) is provided with an inlet valve (2.2), a reactor body (2.3), an agitator (2.4) connected to a stirring paddle (2.5), a DO (Dissolved Oxygen) sensor (2.6), a pH sensor (2.7), a DO / pH meter (2.8), a drain valve (2.9), a mud discharge valve (2.10) and an aeration head (2.11) at the bottom. The system is oxygenated by connecting the aeration head (2.11) through an air pump (2.14), and the aeration volume is adjusted and controlled by an air inlet valve (2.13) and a gas flow meter (2.12). The effluent from the short-range nitrification, denitrification and phosphorus removal reactor (2) is discharged into the drainage tank (5) via a drainage peristaltic pump (2.16), and the sludge is discharged into the sludge tank (3) and the sludge storage tank (4) via a sludge discharge peristaltic pump (2.15). The effective volume of the sludge storage tank (4) for sludge side treatment is 3L, and the effective volume of the reactor body (2.3) is 10L. The reactor is made of organic glass.

[0040] The specific operations are as follows:

[0041] Start-up phase of the short-cut nitrification and denitrification phosphorus removal system: The short-cut nitrification and denitrification phosphorus removal reactor SBR (2) was inoculated with flocculent sludge from the secondary sedimentation tank of an actual sewage treatment plant, and the sludge concentration was maintained at 3000-3500 mg / L.

[0042] The sludge was acclimated to remove phosphorus using oxygen as an electron acceptor using an anaerobic-aerobic operation mode. Domestic sewage was introduced via the inlet peristaltic pump (2.1) and anaerobically stirred for 120 minutes; aerobically aerated for 300 minutes. The dissolved oxygen in the reactor was controlled at 2.0 ± 0.3 mg / L using a gas rotor flowmeter (2.3). The reactor was allowed to settle for 30 minutes and drain for 10 minutes, with a drainage ratio of 50%. The reactor was then left idle for 20 minutes. Three cycles were run daily.

[0043] NH4 in the effluent of SBR reactor (2)+ -N is 2-4 mg / L, NO3 - -N is 0-0.5mg / L, NO2 - -N is 0-0.5 mg / L, PO4 3- -P is 0-0.5 mg / L. After the above indicators are achieved and maintained stably for 15 days, it shows that the enrichment and domestication of polyphosphate bacteria using oxygen as electron acceptor are completed.

[0044] Then, the short-range nitrification, denitrification and phosphorus removal sludge is acclimated in the anaerobic-anoxic-aerobic operation mode. The sewage in the urban sewage raw water tank (1) enters the SBR reactor (2.3) through the peristaltic pump (2.1), and is stirred anaerobically for 120 minutes; anoxic stirring for 180 minutes, aerobic aeration for 120 minutes, and the dissolved oxygen in the reactor is controlled at 2 mg / L by the gas rotor flowmeter (2.3); then it is settled for 30 minutes, drained for 10 minutes, and the drainage ratio is 50%. After drainage, it is idle for 20 minutes, and operated three times a day. When the SBR reactor (2) is in operation, part of the activated sludge is discharged into the sludge box through the sludge pump to maintain the floc sludge concentration in the reactor at 3500±200 mg / L. When the operating conditions are good, a small amount of sludge is discharged into the sludge storage box (4) for standby use, and the sludge age is controlled at 20 to 25 days. When the NH4 + -N concentration is lower than 5 mg / L, nitrite accumulation rate reaches more than 80%, total nitrogen removal rate reaches more than 50%, total phosphorus removal rate reaches more than 80%, and the startup of the short-cut nitrification and denitrification phosphorus removal reactor (2) is completed.

[0045] Short-term nitrification and denitrification phosphorus removal stabilization stage: By adding nitrite nitrogen to the anoxic stage, the nitrite nitrogen accumulation in the anoxic stage is maintained at about 10 mg / L, the growth of bacteria that use nitrite nitrogen as an electron acceptor for denitrification and phosphorus accumulation is enhanced, and the nitrite nitrogen type denitrification and phosphorus accumulation bacteria are gradually acclimated and enriched. The SRT (Sludge Retention Time, sludge age) is controlled at 20-30 days. This stage lasts for 60 days. Every 7 days, about 5% of the effective volume of the reactor is discharged into the sludge storage tank (4) through the sludge discharge peristaltic pump (2.15). The nitrite nitrogen load in the anoxic stage is gradually increased so that the nitrite nitrogen accumulation in the anoxic stage is maintained at about 25 mg / L to test the performance of the sludge under high nitrite nitrogen stress and the effect of sludge side phosphorus removal. At this time, sludge is no longer collected. After about 60 days of operation, when the total phosphorus removal rate of the system is lower than 50%, all the sludge in the sludge storage tank is returned to the short-cut nitrification and denitrification phosphorus removal reactor (2.1), and the nitrite nitrogen concentration during the anoxic period is reduced to 10 mg / L. After a period of operation, if the total phosphorus removal rate recovers to more than 80%, it can be considered that the sludge side phosphorus removal method for maintaining long-term and efficient short-cut nitrification and denitrification phosphorus removal has been successfully started.

[0046] After the reactor is successfully started, the influent is actual domestic sewage, and the NH4 + -N concentration is 50-60 mg / L, NO2 - -N and NO3 - -N concentration is less than 1 mg / L, COD (Chemical Oxygen Demand) is about 200-300 mg / L, and total phosphorus concentration is about 3-8 mg / L. The data of treating domestic sewage after the reactor is in stable operation shows that the total nitrogen in the effluent is less than 10 mg / L, of which NH4 + -N concentration is less than 4 mg / L, NO2 - -N concentration is less than 1 mg / L, NO3 - -N concentration is less than 5 mg / L, COD removal rate is about 75-85%, and total phosphorus concentration is less than 1 mg / L, which can meet the Class A standard.

Claims

1. A method for achieving long-term stable short-range nitrification and denitrification phosphorus removal based on sludge side stream treatment, characterized in that: The specific implementation process is as follows: Phase 1: Construction of a short-cut nitrification and denitrification phosphorus removal system based on sludge side stream treatment; The main body of the short-range nitrification, denitrification and phosphorus removal system is a reactor. The water inlet valve of the reactor is connected to the water inlet peristaltic pump, and the sewage is input into the reactor through the water inlet peristaltic pump; the drain valve on the side of the reactor and the mud discharge valve at the bottom are connected to the drainage peristaltic pump and the mud discharge peristaltic pump respectively, and the treated sewage is discharged into the drainage tank by the drainage peristaltic pump, and the treated sludge is discharged into the mud discharge tank and the mud storage tank respectively by the mud discharge peristaltic pump; an aeration head is installed at the bottom of the reactor, and oxygen is transported to the aeration head through the air inlet valve and then released into the reactor; an agitator is installed on the top of the reactor, and the stirring paddle extends into the sewage; Phase 2: System startup phase; Step 201: Pump sewage into the main reactor through the water inlet peristaltic pump to make the MLSS of the activated sludge in the reactor 3000-3500 mg / L; Step 202: acclimatizing the sewage in the reactor into sludge using oxygen as an electron acceptor for phosphorus removal in an anaerobic-aerobic operation mode; Step 203: Run three cycles per day in an anaerobic-aerobic mode. When the indicators meet the requirements and remain stable for 15 days, it indicates that the enrichment and domestication of polyphosphate bacteria using oxygen as an electron acceptor is complete, and enter the next stage; The third stage: sewage stabilization treatment stage; Step 301: acclimating the short-cut nitrification and denitrification phosphorus removal sludge in an anaerobic-anoxic-aerobic operation mode. During the initial anoxic stirring period, the required sodium nitrite dosage is calculated based on the effective volume of the reactor, and a prepared 100 mg / L high-concentration sodium nitrite solution is added to the reactor to simulate the accumulation of nitrite-nitrogen in the wastewater of 10 mg / L. The sludge is acclimated to denitrification and phosphorus removal using nitrite as an electron acceptor, and three cycles are operated per day. Step 302: When the system indicators meet the requirements and remain stable, the sludge in the reactor is discharged into the sludge discharge tank, and the MLSS of the sludge in the reactor is maintained at 3500±200 mg / L. At the same time, 20% of the effective volume of the reactor is discharged into the sludge storage tank for standby use. The sludge age in the reactor is controlled at 20-25 days. Phase 4: Detoxification of nitrite nitrogen accumulation based on lateral flow treatment; The reactor was operated in an anaerobic-anoxic-aerobic cycle to treat wastewater. Before the anoxic stirring, a 100 mg / L high-concentration sodium nitrite solution was added to the reactor in the amount of sodium nitrite required for the effective volume of the reactor to simulate short-range nitrification and produce high-concentration nitrite nitrogen accumulation. The nitrite nitrogen accumulation in the reactor during the anoxic period was maintained at 25 mg / L. The reactor was operated for three cycles per day. Run for 60 days and observe the water quality. If PO4 3- If -P is higher than 2 mg / L for 7 consecutive days, it means that the activated sludge has been subjected to toxic stress of nitrite nitrogen. At this time, the sludge in the sludge storage tank is added to the reactor at a ratio of 20% of the effective volume of the reactor and the operation is continued; The anaerobic-aerobic operation mode is specifically as follows: anaerobic stirring is performed for 120 minutes while water is fed in, followed by aerobic aeration of the reactor for 300 minutes, followed by sedimentation for 30 minutes, drainage for 10 minutes, with a drainage ratio of 50%, and 20 minutes of idle time after drainage; The anaerobic-anoxic-aerobic operation mode is specifically as follows: while water is being fed in, anaerobic stirring is performed for 120 minutes, followed by anoxic stirring for 180 minutes, and aerobic aeration for 120 minutes; then sedimentation is performed for 30 minutes, drainage is performed for 10 minutes, the drainage ratio is 50%, and after drainage, the reactor is left idle for 20 minutes; The indicators in step 203 include: NH4 in the reactor outlet water + -N is 2-4 mg / L, NO3 - -N is 0-0.5mg / L, NO2 - -N is 0-0.5 mg / L, PO4 3- -P is 0-0.5 mg / L; The indicator in step 302 is: NH4 + -N concentration is lower than 5 mg / L, the nitrite nitrogen accumulation rate reaches more than 80%, the total nitrogen removal rate reaches more than 50%, and the total phosphorus removal rate reaches more than 80%.

2. The method for achieving long-term stable short-range nitrification and denitrification phosphorus removal based on sludge side stream treatment according to claim 1, characterized in that: The short-cut nitrification and denitrification phosphorus removal system monitors the DO and pH values ​​of the sewage in the reactor through a DO sensor and a pH sensor.

3. The method for achieving long-term stable short-range nitrification and denitrification phosphorus removal based on sludge side stream treatment according to claim 1, characterized in that: Under anaerobic stirring conditions, functional bacteria absorb organic carbon sources in sewage and synthesize internal carbon sources PHA and store them in their bodies. At the same time, polyphosphate bacteria will release phosphate particles in their bodies into the water under anaerobic conditions.

4. The method for achieving long-term stable short-range nitrification and denitrification phosphorus removal based on sludge side stream treatment according to claim 3, characterized in that: The functional bacteria include phosphate accumulating bacteria PAOs and DPAOs, glycogen accumulating bacteria GAOs and denitrifying glycogen accumulating bacteria DGAOs.

5. The method for achieving long-term stable short-range nitrification and denitrification phosphorus removal based on sludge side stream treatment according to claim 1, characterized in that: During aerobic aeration, the dissolved oxygen in the reactor was controlled at 2.0 ± 0.3 mg / L by a gas rotor flowmeter.

6. The method for achieving long-term stable short-range nitrification and denitrification phosphorus removal based on sludge side stream treatment according to claim 1, characterized in that: The side stream treatment eliminates the toxicity of nitrite nitrogen accumulation, ensures the activity of sludge in the reactor, and maintains the phosphorus removal rate of the short-range nitrification and denitrification phosphorus removal system at above 80%.

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