Direct ammonia oxidation denitrification unit and its wastewater treatment method

Abstract

The application belongs to the technical field of sewage treatment, and provides a direct ammonia oxidation denitrification device, which comprises biological filler, an aerobic reaction tank, a stirrer, aeration stones, a first water outlet, a second water inlet, a backflow water outlet, a sludge backflow pump, a backflow water inlet, a membrane tank and an MBR membrane assembly; the aerobic reaction tank is internally provided with biological filler and a stirrer; the bottom of the aerobic reaction tank is provided with aeration stones; the aeration stones are connected with an air pump; the top of the membrane tank is provided with a water inlet; the bottom of the membrane tank is provided with a backflow water outlet; the middle of the membrane tank is provided with an MBR membrane assembly; the biological filler is provided with a biological membrane of Alcaligenes sp. HO-1; and the filter diameter of the MBR membrane assembly is not greater than 0.20 microns. The sewage / wastewater biological denitrification device and process based on direct ammonia oxidation provided by the application have high denitrification efficiency and simple denitrification process.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology. Background Technology

[0002] Biological denitrification is currently the mainstream wastewater denitrification technology. It refers to the process by which microorganisms convert organic nitrogen in wastewater into ammonia nitrogen, and then gradually convert the ammonia nitrogen into gaseous nitrogen compounds (nitrogen gas, nitrous oxide, etc.), thus removing nitrogen from wastewater. This technology mainly includes nitrification, denitrification, and anaerobic ammonia oxidation. During nitrification, autotrophic or heterotrophic nitrifying bacteria are needed to oxidize ammonia nitrogen into nitrite or nitrate (NH4+). + -N→NO2 - -N→NO3 - This process (-N) takes place under aerobic conditions and affects NH4+. + Environmental factors such as nitrogen (NO3) and COD are relatively sensitive. During denitrification, denitrifying bacteria reduce nitrate or nitrite nitrogen to nitrogen gas (NO3). - -N→NO2 - The process of nitrogen removal (NO2 → N2O) occurs under anaerobic or anoxic conditions and requires a sufficient carbon source. Therefore, nitrification and denitrification require the synergistic action of multiple bacteria. Anaerobic ammonia oxidation (ANAO) is a highly efficient and low-carbon biological nitrogen removal technology for wastewater treatment. It is carried out under anaerobic conditions, using anaerobic ammonia-oxidizing bacteria to remove nitrite nitrogen (NO2). - -N) acts as an electron acceptor, converting ammonia nitrogen (NH4) into electrons. + -N) is further converted to N2H4 after being converted to N2. Anaerobic ammonia oxidation (ANAO) processes also face many challenges in practical applications. Currently, most global biological nitrogen removal processes for wastewater are developed and constructed based on nitrification, denitrification, and ANAO processes. These processes require the coordinated work of different types of bacteria, including nitrifying bacteria, denitrifying bacteria, and ANAO bacteria. Different types of nitrogen-removing microorganisms have different requirements for nitrogen content, form, dissolved oxygen, and organic matter. Treatment processes need to consider the different dissolved oxygen requirements of microorganisms and design different aerobic-anaerobic oxygen supply units or different aeration strategies. Related processes include autotrophic nitrification-anaerobic-denitrification coupling (AO) processes, short-cut nitrification-denitrification (SHARON) processes, and ANAO-coupled nitrogen removal processes, such as SHARON-ANAMMOX, CANON, and SPDA. Wastewater treatment plants need to carefully design the reactor structure and operating procedures and implement aerobic-anaerobic condition switching to achieve ammonia nitrogen removal.

[0003] Therefore, researching and developing new denitrification technologies and constructing new denitrification processes are of great significance for improving denitrification efficiency, simplifying reactor processes, and reducing energy consumption. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a simple and efficient biological denitrification device based on alkali-producing bacteria strains with direct ammonia oxidation denitrification function. Compared with conventional denitrification devices, it operates under aerobic conditions throughout the process, which not only achieves efficient nitrogen removal, but also reduces the chemical oxygen demand (COD) in wastewater. This device has the advantages of short start-up time, simple structure, and easy operation and management.

[0005] The biological nitrogen removal device for wastewater based on direct ammonia oxidation provided by this invention has a wide range of applications and is green and pollution-free. This invention is suitable for urban domestic wastewater with low influent ammonia nitrogen concentration, and also for aquaculture wastewater with high ammonia nitrogen and high organic matter content.

[0006] This invention provides a direct ammonia oxidation denitrification device, comprising: biological packing material, an aerobic reaction tank, a stirrer, aeration stones, a first outlet, a second inlet, a return outlet, a sludge return pump, a return inlet, a membrane tank, and an MBR membrane module; the aerobic reaction tank has a first outlet at its top; the aerobic reaction tank has a return inlet at its bottom; the aerobic reaction tank contains biological packing material and a stirrer; the bottom of the aerobic reaction tank contains aeration stones; the aeration stones and... An air pump is connected; an inlet is provided at the top of the membrane tank; a return outlet is provided at the bottom of the membrane tank; an MBR membrane module is provided in the middle of the membrane tank; the first outlet and the second inlet are connected by a pipe; the return inlet and the return outlet are connected by a pipe; a sludge return pump is provided on the pipe connecting the return inlet and the return outlet; alkali-producing bacteria are provided in the biological packing material; the filter diameter of the MBR membrane module is no greater than 0.20 μm.

[0007] In the direct ammonia oxidation denitrification unit, during the microbial biofilm formation stage, artificial wastewater is used. The alkali-producing bacteria strain is cultured in shake flasks to the late logarithmic growth phase, with an OD value > 2.0. It is then added to the artificial wastewater at a 5% inoculum rate. The artificial wastewater has an ammonia nitrogen concentration of 600 mg / L and a COD load of 1400 mg / L. During the microbial biofilm formation stage, 0.5 mM hydroxylamine hydrochloride is added daily for 3-5 consecutive days. Once a visible biofilm forms on the immobilized packing material, the immobilization is considered complete.

[0008] In a specific embodiment of the present invention, it further includes a first water inlet, a water pump, and a water inlet pool; the first water inlet is located at the bottom of the aerobic reaction tank; the first water inlet, the water pump, and the water inlet pool are connected in sequence by pipes.

[0009] In a specific embodiment of the present invention, an outlet pump and an outlet pool are also included; the MBR membrane module, the outlet pump and the outlet pool are connected in sequence through pipelines.

[0010] In a specific embodiment of the present invention, the MBR membrane module is a PVDF hollow fiber membrane.

[0011] This invention also provides a method for treating wastewater using a direct ammonia oxidation denitrification device, comprising the following steps: wastewater enters an aerobic reaction tank through a first inlet under the action of an inlet pump; an aeration pump and a stirring device are turned on, and the wastewater is mixed with biological packing material; the fermentation environment of the alkali-producing bacteria on the biological packing material is set as follows: carbon-nitrogen ratio of 2-20, pH value of 5-10, temperature of 15-45℃, and dissolved oxygen of 2-8 mg / L; the treated sludge-wastewater mixture overflows from the aerobic reaction tank through a first outlet, and then flows into a membrane tank through a second inlet; the sludge-wastewater mixture is separated by the MBR membrane module, with the sludge remaining in the membrane tank, and the treated wastewater flows out of the membrane tank through the MBR membrane module under the action of an outlet pump; the remaining sludge in the membrane tank flows out of the membrane tank through a return outlet under the action of a sludge return pump, and then flows back into the aerobic reaction tank through a return inlet. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a direct ammonia oxidation denitrification unit.

[0013] Among them, 1 is the inlet tank, 2 is the inlet pump, 1,1 is the first inlet, 1,2 is the first outlet, 3 is the biological packing material, 4 is the aerobic reaction tank, 5 is the agitator, 6 is the aeration stone, 1.5 is the return inlet, 1.3 is the second inlet, 1.4 is the return outlet, 7 is the sludge return pump, 8 is the MBR membrane module, 9 is the membrane tank, 10 is the effluent pump, and 11 is the effluent tank.

[0014] Figure 2 This is a diagram of biofilm formation on biological packing material.

[0015] Figure 3 This is an enlarged view of a single biological packing material with attached biofilm.

[0016] Figure 4 This is a picture showing an unsuccessful biofilm formation on the biological packing material.

[0017] Figure 5 This is a magnified image showing a single biological packing material failing to attach to a biofilm.

[0018] Figure 6 This is a Gram staining image of a surface biofilm.

[0019] Figure 7 This is an electron microscope image of a surface biofilm. Detailed Implementation

[0020] Example

[0021] This invention provides a direct ammonia oxidation denitrification device, comprising: an inlet pump, an inlet pool, a first inlet, biological packing material, an aerobic reaction tank, a stirrer, an aeration stone, a first outlet, a second inlet, a return outlet, a return inlet, a membrane tank, an MBR membrane module, an outlet pump, an outlet pool, and a sludge return pump.

[0022] The top of the aerobic reaction tank is provided with a first water outlet;

[0023] The bottom of the aerobic reaction tank is provided with a first inlet and a return inlet;

[0024] The aerobic reaction tank contains biological packing material; the biological packing material is permeated with a biofilm of Alcaligenes sp. HO-1CGMCC No.16549; the biological packing material is shaped like a multifaceted hollow sphere, with a reinforcing ring along the circumference of the sphere's center. The upper and lower parts of the reinforcing ring each have 12 ball valves arranged radially along the central axis. The sphere has a diameter of 25 mm and a specific surface area of ​​385 m². 2 / m 3 The biological seasoning is made of polypropylene with a specific gravity of ≈1. Alkali-producing bacteria can be physically adsorbed onto the surface of the filler and grow and reproduce to form a biofilm, thereby achieving immobilization and performing direct ammonia oxidation function.

[0025] Alcaligenes sp. HO-1, CGMCC No. 16549, was deposited at the China General Microbiological Culture Collection Center on September 28, 2018, with accession number CGMCC No. 16549. The strain HO-1 has been described in CN 201811423813.6.

[0026] The bottom of the aerobic reaction tank is equipped with aeration stones, which are connected to an air pump to provide aeration for the aerobic reaction tank.

[0027] The aerobic reaction tank is also equipped with a stirrer.

[0028] The biological filler consists of Φ25 polypropylene microspheres with a specific gravity of approximately 1 and a specific surface area of ​​385 m². 2 / m 3 When direct ammonia-oxidizing bacteria are added to the aerobic reaction tank, they can grow on the biological packing material and form a visible biofilm. The direct ammonia-oxidizing bacteria are strains of the genus *Alcaligenes*.

[0029] The direct ammonia-oxidizing bacteria are added to the bioreactor. During the microbial biofilm formation stage of the direct ammonia oxidation denitrification device, artificial wastewater is used. The alkali-producing bacteria (Alcaligenes sp.) HO-1 are cultured in shake flasks to the late logarithmic growth phase, with an OD value > 2.0. They are then added to the artificial wastewater at a 5% inoculum level. The artificial wastewater has an ammonia nitrogen concentration of 600 mg / L and a COD load of 1400 mg / L. During the microbial biofilm formation stage, 0.5 mM hydroxylamine hydrochloride is added daily for 3-5 consecutive days. Once a visible biofilm forms on the biological packing material, the immobilization is considered complete.

[0030] The aeration tank is used to provide oxygen for the direct ammonia-oxidizing bacteria in the aerobic reaction tank to grow and to help them colonize in the aerobic reaction tank; the aeration tank is also connected to an aeration pump. The aeration pump is used to supply oxygen to the aerobic reaction tank.

[0031] The first water inlet, the water pump, and the water inlet pool are connected in sequence through pipes.

[0032] The membrane tank is provided with an inlet at the top;

[0033] The bottom of the membrane tank is provided with a return outlet;

[0034] An MBR membrane module is installed in the middle of the membrane tank.

[0035] The MBR membrane module is a PVDF hollow fiber membrane with a filter diameter of no more than 0.20 μm. The MBR membrane module effectively intercepts microorganisms and other particulate matter while allowing liquid molecules to pass through, thereby achieving the separation of sludge and water.

[0036] The MBR membrane module, the effluent pump, and the effluent tank are connected in sequence via pipelines.

[0037] The first outlet and the second inlet are connected by a pipe. The sludge / sewage mixture in the aerobic reaction tank flows out of the reaction tank through the first outlet and flows into the membrane tank through the second inlet.

[0038] The return inlet and return outlet are connected by a pipe, and a sludge return pump is installed on the pipe connecting the return inlet and return outlet.

[0039] The sludge / sewage mixture in the membrane tank is separated by the MBR membrane module. The sludge remains in the membrane tank, while the treated wastewater flows into the effluent tank through the MBR membrane module under the action of the effluent pump. The remaining sludge in the membrane tank flows out of the membrane tank through the return outlet under the action of the sludge return pump, and flows into the aerobic reaction tank through the return inlet.

[0040] The present invention also provides a method for treating wastewater using a direct ammonia oxidation denitrification device, comprising the following steps:

[0041] Microbial strains with direct ammonia oxidation function are artificially cultured and propagated before being added to an aerobic reactor. In this reactor, a single reactor is sufficient to effectively remove ammonia nitrogen. The aerobic reactor is equipped with an aeration device and contains biological packing material. Within a specific carbon-to-nitrogen ratio, pH, temperature, and dissolved oxygen range, the functional bacteria can grow in the aerobic reactor, attaching to and forming a biofilm on the biological packing material. After a period of operation, the functional microorganisms become immobilized and exert their direct ammonia oxidation function, achieving highly efficient ammonia nitrogen removal.

[0042] 1. Wastewater enters the aerobic reaction tank through the first inlet under the action of the inlet pump;

[0043] 2. Turn on the aeration pump and the mixing device to mix the sewage with the biological packing material that has been installed.

[0044] In the aerobic reactor, Alcaligenes sp. HO-1 was colonized on the biological packing material. The fermentation environment for the Alcaligenes sp. was set as follows: carbon-to-nitrogen ratio of 2-20, pH of 5-10, temperature of 15-45℃, and dissolved oxygen of 2-8 mg / L. The copy number of the functional gene dnfA of the Alcaligenes sp. was 10. 6 The above or for NH4 + -N removal rate of 80-90% indicates that one-step denitrification has been completed;

[0045] 3. The treated sludge-sewage mixture overflows from the first outlet of the aerobic reaction tank and then flows into the membrane tank through the second inlet.

[0046] 4. After the sludge-sewage mixture is separated by the MBR membrane module, the sludge remains in the membrane tank, and the treated wastewater flows out of the membrane tank through the MBR membrane module under the action of the effluent pump.

[0047] 5. The excess sludge in the membrane tank is discharged from the membrane tank through the return outlet by the sludge return pump and then returned to the aerobic reaction tank through the return inlet.

[0048] Example 1: Treatment effect on artificial wastewater with an ammonia nitrogen load of 200 mg / L:

[0049] Alcaligenes sp. HO-1 was used as the test strain. The influent NH4 in the aerobic reactor was... + With an -N value of 200 mg / L and a COD value of 1400 mg / L, the reactor operated under the conditions of a 20-hour water retention time in the aerobic reaction tank and dissolved oxygen controlled at 1.0-3.0 mg / L. After the reactor reached stability, the NH4+ was then... + -N removal rate was 99.11%, effluent NH4 +-N was 1.77 mg / L; COD removal rate was 94.83%, effluent COD was 157.50 mg / L; TN removal rate was 89.83%, effluent NO2 was... - -N and NO3 - -N concentrations were 3.27 mg / L and 3.73 mg / L, respectively. In the aerobic reactor sludge, the relative abundance of alkali-producing bacteria was 4.73%, and the copy number of the dnfA gene was 5.37 × 10⁻⁶. 9 / mg dry sludge, the amoA gene copy number is 2.65×10 9 / mg dry sludge, the nirS gene copy number is 2.31×10. 8 / mg dry sludge.

[0050] Example 2: Treatment effect on artificial wastewater with an ammonia nitrogen load of 400 mg / L:

[0051] Alcaligenes sp. HO-1 was used as the test strain. The influent NH4 in the aerobic reactor was... + With an -N concentration of 400 mg / L, a COD value of 5600 mg / L, and a water retention time of 20 h in the aerobic reactor, dissolved oxygen was controlled at 1.0-3.0 mg / L. After the reactor reached stability, the NH4+ concentration was... + -N removal rate was 99.11%, effluent NH4 + -N was 4.35 mg / L; COD removal rate was 92.33%, effluent COD was 214.81 mg / L; TN removal rate was 88.21%, effluent NO2 - -N and NO3 - -N concentrations were 16.97 mg / L and 1.60 mg / L, respectively. In the aerobic reactor sludge, the relative abundance of alkali-producing bacteria was 14.47%, and the copy number of the dnfA gene was 1.64 × 10⁻⁶. 10 / mg dry sludge, the amoA gene copy number is 2.36×10 8 / mg dry sludge, the nirS gene copy number is 2.29×10 7 / mg dry sludge.

[0052] Example 3: Treatment effect on artificial wastewater with an ammonia nitrogen load of 600 mg / L and a COD of 7800 mg / L:

[0053] Alcaligenes sp. HO-1 was used as the test strain. The influent NH4 in the aerobic reactor was... +With -N at 600 mg / L, COD at 7800 mg / L, and operating under conditions of 40 h water retention time in the aerobic reactor and dissolved oxygen greater than 5 mg / L, the reactor will stabilize after the NH4+ concentration is reduced. + -N removal rate was 95.25%, effluent NH4 + -N was 28.48 mg / L; COD removal rate was 95.01%, effluent COD was 389.61 mg / L; TN removal rate was 88.11%, effluent NO2 - -N and NO3 - -N concentrations were 1.87 mg / L and 0.41 mg / L, respectively. In the aerobic reactor sludge, the relative abundance of alkali-producing bacteria was 5.70%, and the dnfA gene copy number was 2.23 × 10⁻⁶. 10 / mg dry sludge, the amoA gene copy number is 1.67×10 4 / mg dry sludge, the nirS gene copy number is 2.32×10 8 / mg dry sludge.

[0054] Example 4: Treatment effect on artificial wastewater with an ammonia nitrogen load of 600 mg / L and a COD of 9600 mg / L:

[0055] Using Alcaligenes sp. HO-1 as the test strain, the influent NH4 in the aerobic reactor was tested. + With -N at 600 mg / L, COD at 9600 mg / L, and operating under conditions of 40 h water retention time in the aerobic reactor and dissolved oxygen greater than 5 mg / L, the reactor will stabilize after the NH4+ concentration is reduced. + -N removal rate was 95.55%, effluent NH4 + -N was 26.69 mg / L; COD removal rate was 94.21%, effluent COD was 556.42 mg / L; TN removal rate was 88.10%, effluent NO2 - -N and NO3 - -N concentrations were 0.14 mg / L and 0.12 mg / L, respectively. In the aerobic reactor sludge, the relative abundance of alkali-producing bacteria was 13.95%, and the dnfA gene copy number was 7.59 × 10⁻⁶. 9 / mg dry sludge, the amoA gene copy number is 4.32×10 4 / mg dry sludge, the nirS gene copy number is 2.23×10 4 / mg dry sludge.

[0056] Example 5. Effect of hydroxylamine on the biofilm formation ability of alkali-producing bacteria on packing material surface.

[0057] Two aerobic aeration tanks (Rs and Rc) were constructed using 1L graduated cylinders. 400 mL of synthetic wastewater with an ammonia nitrogen concentration of 600 mg / L and a COD concentration of 9600 mg / L was added to each tank. Alcaligenes sp. HO-1, a cultured bacterium, was added to the aeration tank at a volume ratio of 25% for aeration (aeration rate of 0.4 L / min) at 30℃, and 12 packing materials were added. Simultaneously, 1 mM hydroxylamine hydrochloride was added to aeration tank Rs as the experimental group; no hydroxylamine hydrochloride was added to Rc as the control group. The effect of hydroxylamine pressure on the biofilm formation ability of alkaligenes on the packing material surface was studied. Data obtained after 108 h of culture are shown in Table 1. A clear biofilm structure appeared on the surface of the packing material in the experimental group Rs. Figure 2 and 3 In contrast, no obvious biofilm structure was found on the surface of the Rc packing material in the control group. Figure 4 and 5 Three packing materials were randomly selected from two aeration tanks, and the biofilm weight on their surfaces was measured using a gravimetric method. The biofilm weight on the surface of the experimental group (Rs packing material) was 3.667 ± 0.577 mg biofilm / packing material (dry weight), while the biofilm weight on the surface of the control group (Rc packing material) was 0.667 ± 0.577 mg biofilm / packing material (dry weight). The biofilm weight in the experimental group was significantly higher than that in the control group. The results indicate that the addition of hydroxylamine is beneficial for the formation of biofilms by alkali-producing bacteria on the packing material surface. Gram staining was used to observe (…). Figure 6 ) and electron microscopy observation ( Figure 7 It was found that obvious biofilm structures could only be seen on the surface of the packing material.

[0058] Table 1. Comparison of experimental data on the addition of hydroxylamine hydrochloride

[0059]

[0060] The biological nitrogen removal device and process for wastewater based on direct ammonia oxidation provided by this invention is a type of biological nitrogen removal process with high nitrogen removal efficiency, simple process, low technical threshold, wide applicability, and green and pollution-free characteristics. This invention is suitable for urban domestic sewage with low influent ammonia nitrogen concentration, and also for aquaculture wastewater with high ammonia nitrogen and high organic matter content.

Claims

1. A direct ammonia oxidation denitrification apparatus, characterized by comprising: Biological filler, aerobic reaction tank, agitator, aeration stone; The aerobic reaction tank is internally provided with biological fillers and an agitator; The bottom of the aerobic reaction tank is provided with aeration stones, which are connected with air pumps; The biological packing material is colonized with alkali-producing bacteria ( Alcaligenes sp. ) HO-1 biofilm, the alkali-producing bacteria ( Alcaligenes sp. The accession number for HO-1 is CGMCC No. 16549.

2. The direct ammonia oxidation denitrification device according to claim 1, characterized by The biological filler is a multi-faceted hollow sphere, and a reinforcing ring is arranged at the middle of the sphere along the circumference.

3. The apparatus for direct ammonia oxidation denitrification according to claim 1, characterized in that, The biological filler is made of polypropylene.

4. The apparatus for direct ammonia oxidation denitrification according to claim 1, characterized by, Further comprising a first water outlet, an MBR membrane assembly; The first water outlet is arranged at the top of the aerobic reaction tank; The MBR membrane assembly is arranged at the first water outlet or is connected with the first water outlet through a pipeline; and the filter diameter of the MBR membrane assembly is not greater than 0.20 μm.

5. The apparatus for direct ammonia oxidation denitrification according to claim 1, characterized in that, Further comprising a first water outlet, a second water inlet, a backflow water outlet, a sludge backflow pump, a backflow water inlet, a membrane tank, and an MBR membrane assembly; The first water outlet is arranged at the top of the aerobic reaction tank; and the backflow water inlet is arranged at the bottom of the aerobic reaction tank; The top of the membrane tank is provided with the second water inlet; The bottom of the membrane tank is provided with the backflow water outlet; The middle of the membrane tank is provided with the MBR membrane assembly; the filter diameter of the MBR membrane assembly is not greater than 0.20 μm; and the MBR membrane assembly is connected with the membrane tank water outlet pipeline; The first water outlet and the second water inlet are connected through a pipeline; The backflow water inlet and the backflow water outlet are connected through a pipeline; and the sludge backflow pump is arranged on the pipeline connecting the backflow water inlet and the backflow water outlet.

6. The apparatus for direct ammonia oxidation denitrification according to claim 1, characterized by, Further comprising a first water inlet, a water inlet pump, and a water inlet tank; The first water inlet is arranged at the bottom of the aerobic reaction tank; The first water inlet, the water inlet pump, and the water inlet tank are sequentially connected through pipelines.

7. The apparatus for direct ammonia oxidation denitrification according to claim 4, characterized by Further comprising a water outlet pump and a water outlet tank; The MBR membrane assembly, the water outlet pump, and the water outlet tank are sequentially connected through pipelines.

8. The apparatus for direct ammonia oxidation denitrification according to claim 4, characterized by, The MBR membrane assembly is a PVDF hollow fiber membrane.

9. The method for treating sewage by using the direct ammonia oxidation denitrification device according to any one of claims 1 to 8, characterized in that, comprising the following steps: Sewage enters the aerobic reaction tank from the first water inlet under the action of the water inlet pump; Turn on the aeration pump and the mixing device. The wastewater mixes with the alkali-producing bacteria that have colonized it. Alcaligenes sp. The biofilm of HO-1 is mixed with biological packing material; the alkali-producing bacteria ( Alcaligenes sp. The fermentation environment for HO-1 was set as follows: carbon-to-nitrogen ratio of 2-20, pH of 5-10, temperature of 15-45℃, and dissolved oxygen of 2-8 mg / L. The treated sludge and sewage mixture flows out of the aerobic reaction tank from the first water outlet, and then flows into the membrane tank from the second water inlet; The sludge and sewage mixture is separated by the MBR membrane assembly, the sludge remains in the membrane tank, and the treated sewage flows out of the membrane tank from the MBR membrane assembly under the action of the water outlet pump; The remaining sludge in the membrane tank flows out of the membrane tank from the backflow water outlet under the action of the sludge backflow pump, and then flows back into the aerobic reaction tank from the backflow water inlet.

10. The method for treating sewage by using the direct ammonia oxidation denitrification device according to claim 9, characterized in that, The said biofiller of biofilm of HO-1 is prepared by the following steps: Alcaligenes sp. ) A method for preparing a biofiller of biofilm of HO-1, comprising the following steps: Alcaligenes sp. Alcaligenes sp. ) HO-1 shake flask culture to the late logarithmic growth phase, the amount of growth OD > 2.0, according to 5% inoculation amount to artificial wastewater, artificial wastewater ammonia nitrogen concentration of 600 mg / L, COD load 1400 mg / L, 0.5 mM of hydrochloric acid hydroxylamine was added every day, continuous addition of 3-5 days, until the formation of visible biofilm on the immobilized filler.

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