CN114772725A - Device and method for enhancing nitrogen and phosphorus removal of domestic sewage by coupling sulfur autotrophic short-cut denitrification with anaerobic ammonia oxidation - Google Patents

Abstract

A device and a method for strengthening nitrogen and phosphorus removal of domestic sewage by coupling sulfur autotrophic short-cut denitrification and anaerobic ammonia oxidation belong to the field of activated sludge process urban domestic sewage treatment. The device comprises a water tank, a Sequencing Batch Reactor (SBR), a sulfur autotrophic denitrification anaerobic ammonium oxidation biological filter, an air compressor, a water inlet pump and the like. The method is that low C/N domestic sewage is treated through anaerobic and aerobic stages in a sequencing batch reactor to eliminate organic matter and phosphorus in the sewage. The secondary treatment effluent of a town sewage treatment plant taking nitrate nitrogen as a main pollutant and the effluent of SBR are pumped into a sulfur autotrophic short-cut denitrification anaerobic ammonia oxidation biological filter in proportion, and elemental sulfur of a sulfur particle filter material (consisting of sulfur and siderite) is taken as an electron donor to carry out autotrophic nitrogen removal through a sulfur autotrophic short-cut denitrification coupling anaerobic ammonia oxidation path. The invention can further remove nitrate nitrogen in secondary treatment effluent of the urban sewage treatment plant, and realize the limit denitrification of domestic sewage under the condition of no external carbon source.

Description

A kind of device and method for sulfur autotrophic short-range denitrification coupled with anaerobic ammonia oxidation to strengthen the denitrification and phosphorus removal of domestic sewage

Technical field:

The invention relates to a device and a method for strengthening the denitrification and phosphorus removal of domestic sewage by sulfur autotrophic short-range denitrification coupled with anaerobic ammonia oxidation, and belongs to the field of urban domestic sewage treatment by an activated sludge method. The method is suitable for the high-efficiency and energy-saving denitrification and phosphorus removal process of urban domestic sewage.

Background technique:

With the rapid development of my country's national economy and the continuous growth of the population, the problem of water pollution is becoming more and more serious. Due to the gradual increase of nitrogen and phosphorus pollution, the water body presents a state of eutrophication, which seriously affects the environment and human health. Biological nitrogen and phosphorus removal is widely used in sewage treatment plants as a cost-effective method. The traditional biological denitrification process is that nitrifying bacteria convert ammonia nitrogen into nitrate nitrogen under aerobic conditions, and heterotrophic denitrifying bacteria convert nitrate nitrogen into nitrogen nitrogen under anoxic conditions to achieve nitrogen removal in water. The traditional biological phosphorus removal refers to the use of the characteristics of aerobic excess phosphorus absorption by phosphorus accumulating bacteria under anaerobic and aerobic operating conditions to remove phosphate in the water body. The above two processes use organic matter as the carbon source. However, due to the low C/N characteristics of urban sewage, it is often difficult to meet the requirements of nitrogen and phosphorus removal at the same time. Therefore, it is very important to upgrade the traditional biological nitrogen and phosphorus removal process.

In recent years, anaerobic ammonium oxidation (Anammox), as a new bioautotrophic nitrogen removal process, has received extensive attention from researchers. In this process, ammonia nitrogen reacts directly with nitrite nitrogen under anoxic conditions to generate nitrogen gas. A stable supply of nitrous nitrogen is crucial to the implementation of the Anammox process. Short-range denitrification refers to controlling the traditional whole-process denitrification process in the production stage of nitrous nitrogen to avoid the further reduction of nitrite nitrogen to nitrogen, which can provide Anammox with nitrous nitrogen as a reaction substrate. At present, studies have reported sulfur autotrophic denitrification technology. Autotrophic denitrifying sulfur oxidizing bacteria (SOB) can utilize reduced sulfur (such as S ^2- , S ⁰ , S ₂ O ₃ ^2- ) as electron donors , reducing nitrate or nitrite to nitrogen, this technology can achieve autotrophic denitrification and denitrification without carbon source, and the accumulation of nitrite nitrogen is often observed in sulfur-driven autotrophic denitrification systems, which Provides an opportunity to provide nitrite nitrogen to anammox bacteria.

Therefore, we propose a device method of sulfur autotrophic short-range denitrification coupled with anaerobic ammonia oxidation to enhance the denitrification and phosphorus removal of domestic sewage. The domestic sewage passes through the anaerobic and aerobic stages of SBR to achieve the purpose of removing organic matter and biological phosphorus removal. The pollutants in the secondary treatment effluent of the urban sewage treatment plant are mainly nitrate nitrogen, which is pumped in proportion to the effluent of SBR into the sulfur autotrophic short-range denitrification anammox biological filter, and the sulfur particles filter material. The elemental sulfur is the electron donor, and the sulfur autotrophic short-range denitrification is combined with the anammox denitrification process for biological denitrification. As an advanced treatment technology, the device and method can further remove nitrate nitrogen from the secondary treatment effluent of the urban sewage treatment plant, and realize the ultimate denitrification of domestic sewage without an external carbon source.

SUMMARY OF THE INVENTION

The device for strengthening the denitrification and phosphorus removal of domestic sewage by utilizing sulfur autotrophic short-range denitrification coupled with anaerobic ammonia oxidation is characterized in that: the domestic sewage water tank (1) is connected to the SBR (3) through the first inlet pump (2), and the SBR (3) ), a stirrer (4) and a dissolved oxygen monitoring device (6) are installed; the aeration plate (7) in the SBR (3) is connected to the first air compressor (5); the SBR (3) passes through the first water outlet valve ( 8) Connect with the intermediate water tank (9); the intermediate water tank (9) and the secondary treatment outlet water tank (10) of the urban sewage treatment plant are connected to the sulfur autotrophy through the third inlet water pump (12) and the second inlet water pump (11) respectively. The short-range denitrification anammox biological filter (13) is connected; the sulfur autotrophic short-range denitrification anammox biological filter (13) is connected with the emptying valve (20), and is carried out by the second air compressor (17) Backwashing; the sulfur autotrophic short-range denitrification anammox biological filter (13) is the supporting layer (such as pebbles) and the sulfur particle filter material in order from bottom to top, and the effluent passes through the second water outlet valve (18) and the outlet. The water tank (14) is connected; the water outlet tank (14) is connected with the sulfur autotrophic short-range denitrification anammox biological filter (13) through the return pump (15) for backflow; the effluent in the water outlet tank (14) can be used as a backwash The water backwashes the filter material in the reaction device through the backwash pump (16), and the waste water is discharged through the third water outlet valve (19) after backwashing.

The device for strengthening the denitrification and phosphorus removal of domestic sewage by using sulfur autotrophic short-range denitrification coupled with anaerobic ammonia oxidation includes the following steps: injecting SBR with nitrified sludge in the whole process of sewage treatment plant as inoculated sludge, and maintaining the sludge concentration at 3000~ 3500mg/L, low C/N (<3) actual domestic sewage as raw water enters SBR through the first inlet pump to realize high-load activated sludge process, and the reactor operates in anaerobic/aerobic (A/O) mode, It runs for 5 to 6 cycles every day, each cycle includes 10 minutes of water inflow, 0.5 to 1.5 hours of anaerobic stirring, 0.5 to 1.5 hours of aeration, 0.5 hours of sedimentation, 10 minutes of drainage, and 60 to 230 minutes of idle time, maintaining aerobic conditions through real-time control devices The dissolved oxygen in the first stage is maintained at 2-2.5mg/L, the drainage ratio is maintained at 50%, and the removal of organic matter and phosphorus in the raw water is realized in the SBR. The pollutants in the SBR effluent are mainly ammonia nitrogen, and the pollutants in the secondary treatment effluent of the urban sewage treatment plant are mainly nitrate nitrogen. In the short-range denitrification anammox biological filter, the sulfur autotrophic denitrification bacteria use the elemental sulfur in the sulfur granular filter material as an electron donor to carry out sulfur autotrophic short-range denitrification, and provide the reaction substrate nitrous for anammox. The hydraulic retention time is 1 to 3 hours, and the simultaneous removal of nitrate nitrogen and ammonia nitrogen in the effluent of the secondary treatment of the urban sewage treatment plant is completed, and the effluent is discharged up to the standard.

The present invention realizes through the following technical solutions:

1) System startup

1.1) Start-up of SBR: The nitrified sludge of the sewage treatment plant is injected into SBR (3) as the inoculated sludge. After inoculation, the sludge concentration is maintained at 3000-3500 mg/L, and the sludge is discharged every two days to control the sludge residence time. 25d, the hydraulic retention time is 3-6h, and the operation is at room temperature; the actual domestic sewage is injected into the domestic sewage tank (1) as raw water, and then injected into the SBR (3) through the first inlet pump (2), and it runs for 5-6 cycles per day. Each cycle includes 10 minutes of water inflow, 0.5 to 1.5 hours of anaerobic stirring, 0.5 to 1.5 hours of aeration, 0.5 hours of sedimentation, 10 minutes of drainage, 60 to 230 minutes of idle time, and the drainage ratio is maintained at 50%. When the pollutants in the effluent are mainly ammonia nitrogen, the removal rate of phosphate and COD reaches more than 90%, and the SBR has been operated stably for 15 days or more, it is considered that the SBR has been successfully started.

1.2) Start-up of sulfur autotrophic short-range denitrification anammox biological filter: at room temperature, add sulfur granular filter material to the filter tank to keep the filter material layer height at 1-1.2m, and use the shortage of sewage treatment plant. The activated sludge in the oxygen tank and the anammox floc sludge are used as inoculated sludge, and they are mixed according to the volume ratio of 1:1. The nitrifying bacteria are injected into the sulfur autotrophic short-range denitrification anammox biological filter (13), the ammonia nitrogen and nitrate nitrogen are mixed with water as a mixed nutrient solution, and the mixed nutrient solution is pumped from the water inlet to the bottom of the reactor by a pump , the mixed nutrient solution flows out from the water outlet and then enters the water outlet tank (14), and then is pumped into the reactor from the water inlet, and is pumped in circularly, and the biological filter tank is subjected to microbial domestication and film formation until the nitrate nitrogen removal rate is basically stable at 80% That is, the film hanging is successful, and the start-up of the sulfur autotrophic short-range denitrification anammox biological filter (13) is completed. The composition and content of the nutrient solution in the step (2) are: ammonium chloride (NH ₄ Cl, 30mg/L), potassium nitrate (KNO ₃ , 40mg/L), sodium bicarbonate (NaHCO ₃ , 2g/L) ), magnesium sulfate (MgSO ₄ ·7H ₂ O, 0.14g/L), calcium chloride (CaCl ₂ ·2H ₂ O, 0.14g/L), potassium dihydrogen phosphate (KH ₂ PO ₄ , 0.03g/L) As well as the trace element stock solution required for the growth of microorganisms, the start-up treatment time of the biological filter is 30-50 days.

2) Operation of the system

2.1) Operation of SBR:

SBR runs 5 to 6 cycles per day, anaerobic/aerobic operation, each cycle includes 6 processes of water intake, anaerobic stirring, aeration stirring, sedimentation, drainage and idle, and sludge control is carried out every two days. The mud retention time is 25d.

1. The water inlet setting is 50% of the effective volume of the reactor, and the water inlet switch is controlled by the time-controlled switch. After the system is started, the domestic sewage in the domestic sewage tank (1) is pumped into the SBR through the first inlet pump (2). (3) in;

II Anaerobic stirring: start anaerobic stirring after the water inflow is completed, and set the stirring time to 0.5-1.5h;

III Aeration and stirring: turn on the first air compressor (5), aerate the SBR, supply oxygen, maintain the dissolved oxygen at 2-2.5mg/L through the real-time control device, and set the aeration time at 0.5-1.5h .

IV precipitation: set the precipitation time to 0.5h, and separate the mud and water;

V Drainage: Set the drainage time to 10min and the drainage ratio to 50%; the SBR effluent mainly containing ammonia nitrogen is directly pumped into the sulfur autotrophic short-range denitrification biological filter through the peristaltic pump;

VI Idle: Set the idle time to 60~230min;

2.2) Operation of the sulfur autotrophic short-range denitrification anammox biological filter: when the sulfur autotrophic short-range denitrification anammox biological filter (13) is started up, the secondary treated effluent of the urban sewage treatment plant and the The effluent of the SBR is pumped through the water inlet at a ratio of 1:4 into the sulfur autotrophic short-range denitrification anammox biological filter (13) that has been started in step 1.2), and the hydraulic retention time is adjusted to 1 to 3 hours. The nitrate nitrogen in the secondary treatment effluent of the sewage treatment plant is removed simultaneously with the ammonia nitrogen in the domestic sewage, and the effluent is discharged up to the standard. A part of the effluent in the effluent tank (14) is connected to the sulfur autotrophic short-range denitrification anammox biological filter (13) through a return pump (15) for return flow, and the return flow ratio is 100% to 300%.

2.3) Backwashing process of sulfur autotrophic short-range denitrification anammox biological filter: After the biological filter runs stably for a period of time, the biofilm on the filter material thickens to a certain extent and begins to fall off to a certain extent, microbial activity and The denitrification efficiency of the effluent begins to decline. When the denitrification efficiency of the effluent drops by 5% or more, the operation should be stopped and backwashing should be carried out. The effluent from the water outlet tank (14) can be used as backwashing water to backwash the filter material in the reaction device through the backwashing pump (16). When backwashing is performed, the duration of the gas flushing is 3min and the gas flushing intensity is 10-15L. /(m ² ·s), and then carry out combined air-water flushing for 5 minutes, the water flushing intensity is 7~10L/(m ² ·s), and the last water flushing duration is 3 minutes, and the waste water after backwashing passes through the third outlet valve. (19) to discharge.

To sum up, the present invention provides a method and device for deep nitrogen and phosphorus removal with sulfur autotrophic short-range denitrification coupled with anaerobic ammonia oxidation. Taking urban domestic sewage and secondary treatment effluent of urban sewage treatment plants as the research objects, the domestic sewage with low C/N (<3) is pumped into SBR, and the phosphorus accumulating bacteria firstly release phosphorus in the anaerobic section, and then release the phosphorus in the anaerobic section. The aeration is carried out in the section, the phosphorus accumulating bacteria carry out aerobic excess phosphorus absorption, and the heterotrophic bacteria remove the organic matter in the domestic sewage, so as to achieve the purpose of removing the organic matter and phosphorus in the domestic sewage, and the effluent pollutants are mainly ammonia nitrogen. The pollutants in the secondary treatment effluent of the urban sewage treatment plant are mainly nitrate nitrogen, which and the effluent of SBR are pumped into the sulfur autotrophic short-range denitrification anammox biological filter in proportion to the sulfur autotrophic short-range anammox biological filter. The combination of denitrification and anammox denitrification process for biological denitrification has a good total nitrogen removal effect on low C/N (<3) domestic sewage, and provides a biological denitrification without additional organic carbon source. Nitrogen and phosphorus removal treatment device and method.

Description of drawings:

Figure 1 is a schematic diagram of the structure of the device for the enhanced denitrification and phosphorus removal of domestic sewage by sulfur autotrophic short-range denitrification coupled with anaerobic ammonia oxidation.

(1) is the domestic sewage water tank, (2) is the first inlet pump, (3) is the SBR, (4) is the agitator, (5) is the first air compressor, (6) is the dissolved oxygen monitoring device, ( 7) is the aeration plate, (8) is the first outlet valve, (9) is the intermediate water tank, (10) is the secondary treatment outlet water tank of the urban sewage treatment plant, (11) is the second inlet pump, (12) is the third inlet pump, (13) is the sulfur autotrophic short-range denitrification anammox biological filter, (14) is the outlet tank, (15) is the return pump, (16) is the backwash pump, and (17) is the For the second air compressor, (18) is a second water outlet valve, (19) is a third water outlet valve, and (20) is an emptying valve.

Figure 2 shows the operating mode of the sequencing reactor.

Detailed ways:

The experimental system is shown in Figure 1, each reactor is made of plexiglass, the total volume of the SBR reactor (3) is 11L, and the effective volume is 10L; Volume 12L, effective volume 7.8L.

During the test, the specific water quality of the secondary treatment effluent of the urban sewage treatment plant is as follows: COD concentration is 25-30 mg/L, NO ₃ ^- -N concentration is 15-20 mg/L, NH ₄ ⁺ -N concentration is less than 1 mg/L, NO ₂ ^- -N concentration <1mg/L; the specific water quality of domestic sewage is as follows: COD concentration is 80～200mg/L, NH ₄ ⁺ -N concentration is 45～70mg/L, NO ₂ ^- -N concentration is less than 1mg/L, NO ₃ ^- -N concentration 15～20mg/L.

The present invention will be further described below in conjunction with the accompanying drawings and implementation: the device and method for integrating sulfur autotrophic short-range denitrification coupled with anaerobic ammonium oxidation to strengthen the denitrification and phosphorus removal of domestic sewage, it is characterized in that: the domestic sewage tank (1) passes through the first The inlet water pump (2) is connected to the SBR (3), and the agitator (4) and the dissolved oxygen monitoring device (6) are installed in the SBR (3); the aeration plate (7) in the SBR (3) is connected to the first air compressor (5) Connection; SBR (3) is connected to the intermediate water tank (9) through the first water outlet valve (8); the intermediate water tank (9) and the secondary treatment outlet water tank (10) of the urban sewage treatment plant respectively pass through the third inlet pump (12) and the second feed water pump (11) are connected to the sulfur autotrophic short-range denitrification anammox biological filter (13); the sulfur autotrophic short-range denitrification anammox biological filter (13) is connected to the emptying valve (20) Connected, and backwashed by the second air compressor (17); the sulfur autotrophic short-range denitrification anammox biological filter (13) is the supporting layer (such as pebbles) and sulfur in order from bottom to top. Granular filter material, the effluent is connected to the water outlet tank (14) through the second water outlet valve (18); Backflow is carried out; the effluent in the water outlet tank (14) can be used as backwash water to backwash the filter material in the reaction device through the backwash pump (16), and the waste water after backwashing is discharged through the third water outlet valve (19).

The specific implementation steps are as follows:

1) System startup

1.1) Start-up of SBR: The nitrified sludge of the sewage treatment plant is injected into SBR (3) as the inoculated sludge. After inoculation, the sludge concentration is maintained at 3000-3500 mg/L, and the sludge is discharged every two days to control the sludge residence time. 25d, the hydraulic retention time is 3-6h, and the operation is at room temperature; the actual domestic sewage is injected into the domestic sewage tank (1) as raw water, and then injected into the SBR (3) through the first inlet pump (2), and it runs for 5-6 cycles per day. Each cycle includes 10 minutes of water inflow, 0.5 to 1.5 hours of anaerobic stirring, 0.5 to 1.5 hours of aeration, 0.5 hours of sedimentation, 10 minutes of drainage, 60 to 230 minutes of idle time, and the drainage ratio is maintained at 50%. When the pollutants in the effluent are mainly ammonia nitrogen, the removal rate of phosphate and COD reaches more than 90%, and the SBR has been operated stably for 15 days or more, it is considered that the SBR has been successfully started.

1.2) Start-up of sulfur autotrophic short-range denitrification anammox biological filter: at room temperature, add sulfur granular filter material to the filter tank to keep the filter material layer height at 1-1.2m, and use the shortage of sewage treatment plant. The activated sludge in the oxygen tank and the anammox floc sludge are used as inoculated sludge, and they are mixed according to the volume ratio of 1:1. The nitrifying bacteria are injected into the sulfur autotrophic short-range denitrification anammox biological filter (13), the ammonia nitrogen and nitrate nitrogen are mixed with water as a mixed nutrient solution, and the mixed nutrient solution is pumped from the water inlet to the bottom of the reactor by a pump , the mixed nutrient solution flows out from the water outlet and then enters the water outlet tank (14), and then is pumped into the reactor from the water inlet, and is pumped in circularly, and the biological filter tank is subjected to microbial domestication and film formation until the nitrate nitrogen removal rate is basically stable at 80% That is, the film hanging is successful, and the start-up of the sulfur autotrophic short-range denitrification anammox biological filter (13) is completed. The composition and content of the nutrient solution in the step (2) are: ammonium chloride (NH ₄ Cl, 30mg/L), potassium nitrate (KNO ₃ , 40mg/L), sodium bicarbonate (NaHCO ₃ , 2g/L) ), magnesium sulfate (MgSO ₄ ·7H ₂ O, 0.14g/L), calcium chloride (CaCl ₂ ·2H ₂ O, 0.14g/L), potassium dihydrogen phosphate (KH ₂ PO ₄ , 0.03g/L) As well as the trace element stock solution required for the growth of microorganisms, the start-up treatment time of the biological filter is 30-50 days.

2) Operation of the system

2.1) Operation of SBR:

SBR runs 5 to 6 cycles per day, anaerobic/aerobic operation, each cycle includes 6 processes of water intake, anaerobic stirring, aeration stirring, sedimentation, drainage and idle, and sludge control is carried out every two days. The mud retention time is 25d.

1. The water inlet setting is 50% of the effective volume of the reactor, and the water inlet switch is controlled by the time-controlled switch. After the system is started, the domestic sewage in the domestic sewage tank (1) is pumped into the SBR through the first inlet pump (2). (3) in;

II Anaerobic stirring: start anaerobic stirring after the water inflow is completed, and set the stirring time to 0.5-1.5h;

III Aeration and stirring: turn on the first air compressor (5), aerate the SBR, supply oxygen, maintain the dissolved oxygen at 2-2.5mg/L through the real-time control device, and set the aeration time at 0.5-1.5h .

IV precipitation: set the precipitation time to 0.5h, and separate the mud and water;

V Drainage: Set the drainage time to 10min and the drainage ratio to 50%; the SBR effluent mainly containing ammonia nitrogen is directly pumped into the sulfur autotrophic short-range denitrification biological filter through the peristaltic pump;

VI Idle: Set the idle time to 60~230min;

2.2) Operation of the sulfur autotrophic short-range denitrification anammox biological filter: when the sulfur autotrophic short-range denitrification anammox biological filter (13) is started up, the secondary treated effluent of the urban sewage treatment plant and the The effluent of the SBR is pumped through the water inlet at a ratio of 1:4 into the sulfur autotrophic short-range denitrification anammox biological filter (13) that has been started in step 1.2), and the hydraulic retention time is adjusted to 1 to 3 hours. The nitrate nitrogen in the secondary treatment effluent of the sewage treatment plant is removed simultaneously with the ammonia nitrogen in the domestic sewage, and the effluent is discharged up to the standard. A part of the effluent in the effluent tank (14) is connected to the sulfur autotrophic short-range denitrification anammox biological filter (13) through a return pump (15) for return flow, and the return flow ratio is 100% to 300%.

2.3) Backwashing process of sulfur autotrophic short-range denitrification anammox biological filter: After the biological filter runs stably for a period of time, the biofilm on the filter material thickens to a certain extent and begins to fall off to a certain extent, microbial activity and The denitrification efficiency of the effluent begins to decline. When the denitrification efficiency of the effluent drops by 5% or more, the operation should be stopped and backwashing should be carried out. The effluent from the water outlet tank (14) can be used as backwashing water to backwash the filter material in the reaction device through the backwashing pump (16). When backwashing is performed, the duration of the gas flushing is 3min and the gas flushing intensity is 10-15L. /(m ² ·s), and then carry out combined air-water flushing for 5 minutes, the water flushing intensity is 7~10L/(m ² ·s), and the last water flushing duration is 3 minutes, and the waste water after backwashing passes through the third outlet valve. (19) to discharge.

Claims (2)

1. Utilize the device of the autotrophic short distance denitrification of sulphur coupling anaerobic ammonia oxidation enhanced domestic sewage nitrogen and phosphorus removal, its characterized in that: the domestic sewage water tank (1) is connected with an SBR (sequencing batch reactor) (3) through a first water inlet pump (2), and a stirrer (4) and a dissolved oxygen monitoring device (6) are installed in the SBR (3); an aeration disc (7) in the SBR (3) is connected with a first air compressor (5); the SBR (3) is connected with the middle water tank (9) through a first water outlet valve (8); the intermediate water tank (9) and a secondary treatment water outlet tank (10) of a town sewage treatment plant are respectively connected with a sulfur autotrophic short-cut denitrification anaerobic ammonia oxidation biological filter (13) through a third water inlet pump (12) and a second water inlet pump (11); the sulfur autotrophic short-cut denitrification anaerobic ammonium oxidation biological filter (13) is connected with an exhaust valve (20) and is subjected to reverse air washing by a second air compressor (17); the sulfur autotrophic short-cut denitrification anaerobic ammonium oxidation biological filter (13) is sequentially provided with a supporting layer (such as cobblestones) and a sulfur particle filter material from bottom to top, and effluent is connected with an effluent tank (14) through a second effluent valve (18); the water outlet tank (14) is connected with the sulfur autotrophic short-cut denitrification anaerobic ammonia oxidation biological filter (13) through a reflux pump (15) for reflux; the effluent in the water outlet tank (14) can be used as backwash water to backwash the filter material in the reaction device through a backwash pump (16), and the wastewater after backwashing is discharged through a third water outlet valve (19).

2. Method for applying the device according to claim 1, characterized in that it comprises the following steps:

injecting whole course nitrified sludge of a sewage treatment plant into SBR as inoculated sludge, keeping the sludge concentration at 3000-3500 mg/L after inoculation, enabling actual domestic sewage with C/N less than 3 to enter the SBR as raw water through a first water inlet pump to realize a high-load activated sludge method, operating a reactor in an anaerobic/aerobic mode for 5-6 periods each day, wherein each period comprises water inlet for 10min, anaerobic stirring for 0.5-1.5 h, aeration for 0.5-1.5 h, sedimentation for 0.5h, water drainage for 10min, idling for 60-230 min, keeping dissolved oxygen in an aerobic section at 2-2.5 mg/L through a real-time control device, keeping the water drainage ratio at 50%, and removing organic matters and phosphorus in the raw water in the SBR;

the pollutants in the SBR effluent mainly comprise ammonia nitrogen, the pollutants in the secondary treatment effluent of the urban sewage treatment plant mainly comprise nitrate nitrogen, the nitrate nitrogen and the sulfur are pumped into a sulfur autotrophic short-range denitrification anaerobic ammonium oxidation biological filter through a water inlet according to the volume ratio of 1:4, sulfur autotrophic denitrification bacteria use elemental sulfur in a sulfur particle filter material as an electron donor to perform sulfur autotrophic short-range denitrification so as to provide reaction substrate nitrite nitrogen for anaerobic ammonium oxidation, the hydraulic retention time is 1-3 h, the synchronous removal of the nitrate nitrogen in the secondary treatment effluent of the urban sewage treatment plant and the ammonia nitrogen in domestic sewage is completed, and the effluent is discharged after reaching the standard; the effluent water tank is connected with the sulfur autotrophic short-cut denitrification anaerobic ammonium oxidation biological filter through a reflux pump for reflux, and the reflux ratio is 100-300%; after the biological filter tank is operated for a period of time, when the denitrification efficiency of the outlet water is reduced by 5 percent or more, the impurities retained in the filter material layer need to be removed by back washing, the outlet water in the outlet water tank can be used as back washing water to back wash the filler in the reaction device by a back washing pump, and when the back washing is carried out, the method of air-water combined washing is adopted, and the waste water after the back washing is directly discharged by a drain valve.

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