Continuous nitrifying bacteria enrichment culture method and device

Abstract

The invention relates to a continuous nitrifying bacteria enrichment culture method and device, and belongs to the technical field of wastewater biological treatment. The device comprises a reactor and a sedimentation tank, a first gallery and a plurality of second galleries are sequentially arranged in the reactor; a water inlet and an alkali adding opening are formed in the side wall, far away from the sedimentation tank, in the reactor; a mixed liquid inlet is further formed in the side wall, provided with the water inlet, of the reactor, a mixed liquid outlet is formed in the position, close to the sedimentation tank, of the top wall of the reactor, the mixed liquid inlet and the mixed liquid outlet are communicated through a mixed liquid circulating pipeline, and a mixed liquid pump is arranged on the mixed liquid circulating pipeline. The continuous plug flow reaction container is adopted as a reactor for enrichment culture of the nitrifying bacteria, the mixed liquid inlet and the mixed liquid outlet are formed in the reactor to form circulation of the mixed liquid, the nitrifying bacteria are subjected to enrichment culture, after 30 days of culture, the nitrification rate of the nitrifying bacteria is increased by 2.4 times, and the ammonia nitrogen removal efficiency is increased to 93% from 75%.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater biological treatment, and particularly relates to a continuous nitrifying bacteria enrichment and cultivation method and device. Background Art

[0002] In the process of wastewater biochemical treatment, the removal of ammonia nitrogen mainly relies on nitrifying bacteria, which are autotrophic microorganisms with long generation time, slow reproduction rate, sensitivity to water temperature, dissolved oxygen, and toxic substances, and weak impact resistance, resulting in unstable nitrification function of the biochemical system. Therefore, the stable and standard discharge of ammonia nitrogen is a major problem faced by sewage treatment plants.

[0003] Adding nitrifying bacteria is an effective way to quickly restore nitrification function. The sources of nitrifying bacteria are pure culture on the one hand and activated sludge enrichment culture on the other. Both methods have their own advantages and disadvantages. Overall, the use of activated sludge enrichment culture of nitrifying bacteria has the advantages of rich strains, high environmental adaptability and low cost, so it has greater advantages in practical applications.

[0004] The device for enriching and culturing nitrifying bacteria with activated sludge generally adopts a sequencing batch reactor, which is easy to operate and the parameters are easy to control. However, since there is only nitrification in the system, nitrate nitrogen will continue to accumulate, thereby inhibiting the growth of nitrifying bacteria. Like the existing nitrifying bacteria enrichment and cultivation methods, Zhejiang University has disclosed a sequencing batch full-process nitrifying bacteria enrichment device and method based on soft fillers. The reactor body is a cylindrical tank body, and the inside of the tank body is filled with soft fillers. A reflux port is set at the bottom of the reactor. The reflux liquid is continuously lifted from the bottom of the reactor to the top through a reflux pump to realize the internal circulation of the reactor, increase the contact between the activated sludge and the soft filler, and the culture agent formula is composed of 12 reagents such as ammonium chloride. After 210 days of cultivation, the relative abundance of comammox increased by 16 times. Considering the needs of nitrifying bacteria for the growth environment, it is necessary to provide a continuous nitrifying bacteria enrichment and cultivation method and device. Summary of the invention

[0005] In view of the above problems, the present invention provides a continuous nitrifying bacteria enrichment and cultivation method and device, which adopts a continuous reactor and fixes fillers in the reactor to overcome the shortcomings of nitrate nitrogen accumulation and biomass loss in traditional enrichment devices and provide a suitable environment for the survival of nitrifying bacteria.

[0006] The first object of the present invention is to provide a continuous nitrifying bacteria enrichment and cultivation device.

[0007] The culture device comprises a reactor and a sedimentation tank connected to the reactor, the reactor adopts a continuous plug flow container, and the reactor is used for enrichment culture of nitrifying bacteria;

[0008] In the plug flow direction, a first gallery and a plurality of second galleries are sequentially arranged in the reactor;

[0009] A stirrer is provided on the top wall of the reactor, an output end of the stirrer penetrates the top wall of the reactor and extends into the first gallery and is connected with a stirring blade, a filler is suspended in the second gallery, and an aerator is provided at the bottom of the second gallery;

[0010] A water inlet and an alkali adding port are provided on the side wall of the reactor away from the sedimentation tank;

[0011] The side wall of the reactor with the water inlet is also provided with a mixed liquid inlet, and the top wall of the reactor is provided with a mixed liquid outlet near the settling tank. The mixed liquid inlet and the mixed liquid outlet are connected through a mixed liquid circulation pipeline, and a mixed liquid pump is provided on the mixed liquid circulation pipeline.

[0012] In an embodiment of the present invention, a water outlet is provided at the top of the side wall of the sedimentation tank away from the reactor.

[0013] In the embodiment of the present invention, the water outlet is connected to a water outlet bucket.

[0014] In an embodiment of the present invention, a return sludge inlet is also provided on the side wall of the reactor where the water inlet is provided, a return sludge outlet is provided at the bottom of the sedimentation tank, the return sludge inlet is connected to the return sludge outlet through a return sludge pipeline, and a return sludge pump is provided on the return sludge pipeline.

[0015] In the embodiment of the present invention, the water inlet is connected to a water adding bucket, and the alkali adding port is connected to an alkali adding bucket.

[0016] In an embodiment of the present invention, the aerator is connected to an aerator via an aeration pipeline.

[0017] In an embodiment of the present invention, a flow meter is provided on the aeration pipeline.

[0018] The present invention provides a continuous nitrifying bacteria enrichment and culture method, which is implemented in the above-mentioned continuous nitrifying bacteria enrichment and culture device, and includes:

[0019] Adding activated sludge into a first gallery and a plurality of second pipes sequentially arranged in the reactor;

[0020] suspending fillers in a plurality of said second pipes;

[0021] The wastewater rich in nutrient solution and the alkali solution are added from the water inlet and the alkali adding port of the reactor respectively;

[0022] Turning on the agitator on the top wall of the reactor to drive the agitator blades in the first gallery to rotate, agitating the wastewater rich in nutrient solution and the activated sludge to form a mixed solution;

[0023] opening the aerator at the bottom of the second pipe;

[0024] Connecting the mixed liquid inlet on the side wall of the reactor provided with the water inlet and the mixed liquid outlet on the side wall of the reactor away from the water inlet through a mixed liquid circulation pipeline, and turning on the mixed liquid pump on the mixed liquid circulation pipeline;

[0025] After the mixed liquid reacts in the reactor, it enters the sedimentation tank connected to the reactor. After sedimentation, the supernatant is discharged from the outlet of the sedimentation tank.

[0026] In an embodiment of the present invention, the activated sludge concentration is 8-9 g / L, the activated sludge inoculation amount accounts for 50-55% of the effective volume of the reactor, the wastewater rich in nutrient solution is prepared by adding ammonium chloride to industrial wastewater, and the components of the industrial wastewater are: COD is 400 mg / L-500 mg / L, ammonia nitrogen is 20 mg / L-30 mg / L, and the amount of ammonium chloride added is 110-120 mg / L industrial wastewater.

[0027] In an embodiment of the present invention, the dissolved oxygen in the first gallery is controlled to be below 0.5 mg / L, and the dissolved oxygen in the second gallery is controlled to be above 2 mg / L.

[0028] In the embodiment of the present invention, the filler is a combination of soft fiber material and plastic in an annular structure.

[0029] In the embodiment of the present invention, the internal circulation ratio of the mixed liquid is 300% to 400%.

[0030] In an embodiment of the present invention, the culture method is characterized in that it also includes a return sludge return step, specifically:

[0031] Connecting the return sludge inlet and the return sludge outlet through a return sludge pipeline;

[0032] Turn on the return sludge pump on the return sludge line.

[0033] In the embodiment of the present invention, the return ratio of the return sludge is 100%.

[0034] Beneficial effects of the present invention:

[0035] The present invention provides a continuous nitrifying bacteria enrichment culture method and device. A continuous plug flow reaction container is used as a reactor for nitrifying bacteria enrichment culture, and a mixed liquid inlet and a mixed liquid outlet are arranged on the reactor to form a mixed liquid circulation, so as to enrich and culture the nitrifying bacteria. After 30 days of culture, the nitrification rate of the nitrifying bacteria is increased by 2.4 times, and the ammonia nitrogen removal efficiency is increased from 75% to 93%. After 210 days of culture, the nitrification rate of the nitrifying bacteria is increased by 16.8 times, which can effectively reduce the accumulation of nitrate nitrogen in the system.

[0036] The present invention adopts a hanging filler carrier to facilitate the attached growth of nitrifying bacteria and avoid biomass loss.

[0037] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A schematic structural diagram of a continuous nitrifying bacteria enrichment and cultivation device according to an embodiment of the present invention is shown;

[0040] In the figure: 10, water adding bucket; 20, alkali barrel; 30, reactor; 310, first gallery; 311, agitator; 320, second gallery; 321, aerator; 322, filler; 33, mixed liquid inlet; 34, mixed liquid outlet; 35, discharge outlet; 36, return sludge inlet; 40, sedimentation tank; 41, mud intake port; 42, return sludge outlet; 50, water outlet bucket; 60, aerator; 61, flow meter. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] like Figure 1 As shown, a continuous nitrifying bacteria enrichment and cultivation device according to an embodiment of the present invention includes a reactor 30 and a sedimentation tank 40 connected to the reactor 30;

[0043] The reactor 30 adopts a continuous plug flow container, and the reaction container 30 is used for enrichment and cultivation of nitrifying bacteria;

[0044] In the push flow direction, the reactor 30 is provided with a first gallery 310 and a plurality of second galleries 320 in sequence;

[0045] A stirrer 311 is provided on the top wall of the reactor 30, and the output end of the stirrer 311 passes through the top wall of the reactor 30 and extends into the first gallery 310, and is connected with a stirring blade;

[0046] A filler 322 is suspended in the second gallery 320 , and an aerator 321 is provided at the bottom of the second gallery 320 ;

[0047] A water inlet and an alkali addition port are provided on the side wall of the reactor 30 away from the sedimentation tank 40;

[0048] The reactor 30 is provided with a mixed liquid inlet 33 on the side wall where the water inlet is provided, and a mixed liquid outlet 34 is provided on the top wall of the reactor 30 near the settling tank 40. The mixed liquid inlet 33 and the mixed liquid outlet 34 are connected through a mixed liquid circulation pipeline. A mixed liquid pump is provided on the mixed liquid circulation pipeline so that the mixed liquid in the reactor 30 can circulate internally and fully react in the reactor 30. Under the action of the mixed liquid, the nitrate nitrogen (same as the mixed liquid) produced during the nitrifying bacteria enrichment process returns to the first gallery 310, and the nitrate nitrogen is converted into nitrogen gas and released in the anoxic environment of the first gallery 310, thereby reducing the accumulation of nitrate nitrogen in the system.

[0049] A water outlet is provided at the top of the side wall of the sedimentation tank 40 away from the reactor 30 .

[0050] In the embodiment of the present invention, the connection point between the reactor 30 and the sedimentation tank 40 is a discharge port 35 .

[0051] In the embodiment of the present invention, the number of the second corridors 320 can be set according to the comprehensive consideration of the nitrification rate of nitrifying bacteria, ammonia nitrogen removal efficiency and production cost in the specific implementation. Preferably, the number of the second corridors 320 is 6;

[0052] The present invention does not limit the size of the first corridor 310 and the second corridor 320. For the convenience of manufacturing the device, in the present embodiment, the first corridor 310 and several second corridors 320 are of the same size. The length, width and height of each corridor are 300mm×200mm×300mm, and the total volume is 18L. The effective volume of the reactor 30 is 15L.

[0053] A return sludge inlet 36 is also provided on the side wall of the reactor 30 where the water inlet is provided. A return sludge outlet 42 is provided at the bottom of the sedimentation tank 40. The return sludge inlet 36 is connected to the return sludge outlet 42 through a return sludge pipeline. A return sludge pump is provided on the return sludge pipeline so that the sludge in the sedimentation tank can flow back to the reactor 30 for further denitrification, thereby improving the utilization rate of the reaction raw materials.

[0054] In certain embodiments of the present invention, the water inlet is connected to a water adding bucket 10, which is used to hold wastewater that has been configured with nutrient solution to facilitate the continuity of nitrifying bacteria enrichment culture. The alkali adding port is connected to an alkali adding bucket 20, which is used to hold the alkali solution required for nitrifying bacteria enrichment culture. The connecting pipeline between the water inlet and the water adding bucket 10 and the connecting pipeline between the alkali adding port and the alkali adding bucket 20 are both provided with water pumps.

[0055] In some embodiments of the present invention, the aerator 321 is connected to the aerator 60 via an aeration pipeline, and a flow meter 61 is provided on the aeration pipeline, and the flow meter 61 is used to control the aeration amount.

[0056] In some embodiments of the present invention, the water outlet is connected to a water outlet bucket 50, and the water outlet bucket 50 is used to collect or store water after nitrifying bacteria enrichment.

[0057] In some embodiments of the present invention, the bottom of the sedimentation tank 40 is conical, and a mud intake port 41 is provided on the conical outer wall of the sedimentation tank 40 . The mud intake port 41 is provided to facilitate cleaning of the silt deposited at the bottom of the sedimentation tank 40 .

[0058] In some other embodiments of the present invention, a continuous nitrifying bacteria enrichment culture method is provided, which is implemented in the continuous nitrifying bacteria enrichment culture device described in the above embodiments, comprising:

[0059] Adding activated sludge into the first gallery 310 and a plurality of second pipes sequentially provided in the reactor 30;

[0060] Suspending fillers 322 in a plurality of said second pipes;

[0061] Adding nutrient solution-rich wastewater and alkali solution from the water inlet and alkali adding port of the reactor 30, respectively;

[0062] Turning on the agitator 311 on the top wall of the reactor 30 to drive the agitator blades in the first gallery 310 to rotate, agitating the wastewater rich in nutrient solution and the activated sludge to form a mixed solution;

[0063] Open the aerator 321 at the bottom of the second pipeline;

[0064] After the mixed liquid reacts in the reactor 30 , it enters the sedimentation tank connected to the reactor 30 . After sedimentation, the supernatant is discharged from the outlet of the sedimentation tank 40 .

[0065] In the embodiment of the present invention, the activated sludge concentration is 8-9 g / L, and the activated sludge inoculum accounts for 50-55% of the effective volume of the reactor 30 . Preferably, the activated sludge inoculum accounts for 50% of the effective volume of the reactor 30 .

[0066] In an embodiment of the present invention, the pH value of the alkali solution is controlled at 7.5-8.5, the alkali in the alkali solution is sodium carbonate or sodium bicarbonate, and when sodium carbonate is added, the amount of sodium carbonate added is 480-500 mg / L industrial wastewater, preferably, the amount of sodium carbonate added is 500 mg / L.

[0067] In an embodiment of the present invention, the wastewater rich in nutrient solution is prepared by adding ammonium chloride to industrial wastewater, the components of the industrial wastewater: COD is 400mg / L-500mg / L, ammonia nitrogen is 20mg / L-30mg / L, the amount of ammonium chloride added is 110-120mg / L industrial wastewater, preferably, the amount of ammonium chloride added is 115mg / L industrial wastewater;

[0068] In the embodiment of the present invention, the flow rate of the wastewater rich in nutrient solution entering the reactor 30 is 4-6 L / h, preferably 4 L / h.

[0069] In the embodiment of the present invention, the dissolved oxygen in the first corridor 310 is controlled below 0.5 mg / L, and the dissolved oxygen in the second corridor 320 is controlled above 2 mg / L.

[0070] In the embodiment of the present invention, the filler 322 is a combination of soft fiber material and plastic in an annular structure.

[0071] In certain embodiments of the present invention, the culture method further comprises an internal circulation step of the mixed solution in the reactor 30, specifically:

[0072] A mixed liquid inlet 33 on the side wall of the reactor 30 provided with a water inlet and a mixed liquid outlet 34 on the side wall of the reactor 30 away from the water inlet are connected through a mixed liquid circulation pipeline;

[0073] Turn on the mixed liquid pump on the mixed liquid circulation line.

[0074] In the embodiment of the present invention, the internal circulation ratio of the mixed liquid is 300% to 400%.

[0075] In an embodiment of the present invention, the culture method further comprises a return step of return sludge, specifically:

[0076] The return sludge inlet 36 on the side wall of the reactor 30 provided with the water inlet is connected with the return sludge outlet 42 at the bottom of the sedimentation tank 40 through a return sludge pipeline;

[0077] Turn on the return sludge pump on the return sludge line.

[0078] In the embodiment of the present invention, the return ratio of the return sludge is 100%.

[0079] Example 1

[0080] The nitrifying bacteria enrichment culture method includes:

[0081] Step 1: Add activated sludge into the first gallery 310 and a plurality of second pipes sequentially provided in the reactor 30, wherein the activated sludge concentration is 8-9 g / L, and the activated sludge inoculum accounts for 50% of the effective volume of the reactor 30;

[0082] Step 2: Hang fillers 322 in a plurality of the second pipes, wherein the fillers 322 are a combination of a soft fiber material and a plastic structure in an annular structure;

[0083] Step 3, adding nutrient solution-rich wastewater and alkali solution from the water inlet and alkali addition port of the reactor 30, respectively, wherein the nutrient solution-rich wastewater is prepared by adding ammonium chloride to industrial wastewater, the industrial wastewater composition: COD is 400 mg / L, ammonia nitrogen is 20 mg / L, the amount of ammonium chloride added is 115 mg / L, the alkali solution is sodium carbonate solution, the pH value of the sodium carbonate solution is controlled at 7.5-8.5, and the amount of sodium carbonate added is 500 mg / L industrial wastewater;

[0084] Step 4: turning on the agitator 311 on the top wall of the reactor 30 to drive the agitator blades in the first gallery 310 to rotate, stirring the wastewater rich in nutrient solution and the activated sludge to form a mixed solution;

[0085] Step 5: Open the aerator 321 at the bottom of the second pipeline, wherein the dissolved oxygen in the first gallery 310 is controlled to be below 0.5 mg / L, and the dissolved oxygen in the second gallery 320 is controlled to be above 2 mg / L;

[0086] Step 6: connect the mixed liquid inlet 33 on the side wall of the reactor 30 with the water inlet and the mixed liquid outlet 34 on the side wall of the reactor 30 away from the water inlet through the mixed liquid circulation pipeline, turn on the mixed liquid pump on the mixed liquid circulation pipeline, and ensure that the internal circulation ratio of the mixed liquid is 300%. Under the action of the mixed liquid, the nitrate nitrogen (same as the mixed liquid) produced in the process of nitrifying bacteria enrichment returns to the first gallery 310, and the nitrate nitrogen is converted into nitrogen gas and released in the anoxic environment of the first gallery 310, thereby reducing the accumulation of nitrate nitrogen in the system;

[0087] Step 7: Connect the return sludge inlet 36 on the side wall of the reactor 30 with the water inlet and the return sludge outlet 42 at the bottom of the sedimentation tank 40 through the return sludge pipeline, and turn on the return sludge pump on the return sludge pipeline to ensure that the return ratio of the return sludge is 100%;

[0088] Step eight, under the action of water plugging, the mixed liquid passes through the first gallery 310 and the remaining five second galleries 320 in sequence, and flows to the sedimentation tank 40 through the discharge port 35 of the reactor 30 and the pipeline. The mixed liquid settles by gravity in the sedimentation tank 40, and the sludge and water are layered. The upper layer of liquid is the supernatant, which flows into the water outlet bucket 50 through the outlet and pipeline of the sedimentation tank 40. The lower layer of liquid is the return sludge, which is pumped into the return sludge inlet 36 through the return sludge outlet 42 and the return sludge pipeline under the action of the return sludge pump, and then returns to the reactor 30.

[0089] After 30 days of cultivation, the nitrification rate of the nitrifying bacteria in the reactor 30 increased by 2.4 times (compared with the nitrification rate of the initial nitrifying bacteria enrichment culture), and the ammonia nitrogen removal efficiency increased from 75% to 93%.

[0090] After 210 days of cultivation, the nitrification rate of nitrifying bacteria increased by 16.8 times (compared with the nitrification rate of the initial nitrifying bacteria enrichment culture), and the ammonia nitrogen removal efficiency increased from 75% to 96%.

[0091] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A continuous nitrifying bacteria enrichment and culture device, comprising a reactor (30) and a sedimentation tank (40) connected to the reactor (30), characterized in that: The reactor (30) is a continuous plug flow container, and the reactor (30) is used for enrichment and cultivation of nitrifying bacteria; In the push flow direction, a first gallery (310) and a plurality of second galleries (320) are sequentially arranged in the reactor (30); A stirrer (311) is provided on the top wall of the reactor (30); an output end of the stirrer (311) penetrates the top wall of the reactor (30) and extends into the first gallery (310) and is connected to a stirring blade; a filler (322) is suspended in the second gallery (320); and an aerator (321) is provided at the bottom of the second gallery (320); A water inlet and an alkali addition port are provided on the side wall of the reactor (30) away from the sedimentation tank (40); The side wall of the reactor (30) having the water inlet is also provided with a mixed liquid inlet (33), and the top wall of the reactor (30) is provided with a mixed liquid outlet (34) near the settling tank (40). The mixed liquid inlet (33) and the mixed liquid outlet (34) are connected through a mixed liquid circulation pipeline, and a mixed liquid pump is provided on the mixed liquid circulation pipeline.

2. The continuous nitrifying bacteria enrichment and cultivation device according to claim 1, characterized in that: A water outlet is provided at the top of the side wall of the sedimentation tank (40) away from the reactor (30).

3. The continuous nitrifying bacteria enrichment and cultivation device according to claim 1, characterized in that: The water outlet is connected to a water outlet bucket (50).

4. The continuous nitrifying bacteria enrichment and cultivation device according to claim 1, characterized in that: A return sludge inlet (36) is also provided on the side wall of the reactor (30) where the water inlet is provided, and a return sludge outlet (42) is provided at the bottom of the sedimentation tank (40). The return sludge inlet (36) is connected to the return sludge outlet (42) via a return sludge pipeline, and a return sludge pump is provided on the return sludge pipeline.

5. The continuous nitrifying bacteria enrichment and cultivation device according to claim 1, characterized in that: The water inlet is connected to a water adding bucket, and the alkali adding port is connected to an alkali adding bucket (20).

6. The continuous nitrifying bacteria enrichment and culture device according to any one of claims 1 to 5, characterized in that: The aerator (321) is connected to an aerator (60) via an aeration pipeline.

7. The continuous nitrifying bacteria enrichment and cultivation device according to claim 6, characterized in that: A flow meter (61) is provided on the aeration pipeline.

8. A continuous nitrifying bacteria enrichment and cultivation method, characterized in that: The method is implemented in the continuous nitrifying bacteria enrichment culture device according to any one of claims 1 to 6, comprising: Adding activated sludge into a first gallery (310) and a plurality of second pipes sequentially arranged in a reactor (30); Suspending fillers (322) in a plurality of said second pipes; Adding wastewater rich in nutrient solution and alkali solution from the water inlet and alkali adding port of the reactor (30) respectively; Turning on the agitator (311) on the top wall of the reactor (30) to drive the agitator blades in the first gallery (310) to rotate, agitating the wastewater rich in nutrient solution and the activated sludge to form a mixed solution; Opening the aerator (321) at the bottom of the second pipeline; Connecting a mixed liquid inlet (33) on the side wall of the reactor (30) provided with a water inlet and a mixed liquid outlet (34) on the side wall of the reactor (30) away from the water inlet through a mixed liquid circulation pipeline, and turning on a mixed liquid pump on the mixed liquid circulation pipeline; After the mixed liquid reacts in the reactor (30), it enters the sedimentation tank (7) connected to the reactor (30). After sedimentation, the supernatant is discharged from the outlet of the sedimentation tank (40).

9. The continuous nitrifying bacteria enrichment and cultivation method according to claim 8, characterized in that: The activated sludge concentration is 8-9 g / L, the activated sludge inoculation amount accounts for 50-55% of the effective volume of the reactor (30), the wastewater rich in nutrient solution is prepared by adding ammonium chloride to industrial wastewater, the components of the industrial wastewater are: COD is 400 mg / L-500 mg / L, ammonia nitrogen is 20 mg / L-30 mg / L, and the amount of ammonium chloride added is 110-120 mg / L industrial wastewater.

10. The continuous nitrifying bacteria enrichment and cultivation method according to claim 8, characterized in that: The dissolved oxygen in the first corridor (310) is controlled to be below 0.5 mg / L, and the dissolved oxygen in the second corridor (320) is controlled to be above 2 mg / L.

11. The continuous nitrifying bacteria enrichment and cultivation method according to claim 8, characterized in that: The filler (322) is composed of a soft fiber material and a plastic with an annular structure.

12. The continuous nitrifying bacteria enrichment and cultivation method according to claim 8, characterized in that: The internal circulation ratio of the mixed liquid is 300% to 400%.

13. The continuous nitrifying bacteria enrichment and culture method according to any one of claims 8 to 12, characterized in that: It also includes the return step of the return sludge, specifically: Connecting the return sludge inlet (36) and the return sludge outlet (42) via a return sludge pipeline; Turn on the return sludge pump on the return sludge line.

14. The continuous nitrifying bacteria enrichment and cultivation method according to claim 13, characterized in that: The return ratio of the return sludge is 100%.

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