A deep denitrification device based on full-ammonia oxidation coupled with sulfur autotrophic denitrification and a starting method thereof

Abstract

This invention discloses a deep denitrification device and its start-up method based on full-process ammonia oxidation coupled with sulfur autotrophic denitrification, belonging to the field of wastewater biological treatment technology. First, sludge containing full-process ammonia oxidizing bacteria is inoculated into the reactor; then, wastewater containing ammonia nitrogen is continuously introduced, gradually increasing the ammonia nitrogen concentration to enrich the full-process ammonia oxidizing bacteria; finally, sulfide is added to the influent, gradually increasing the sulfide concentration to enrich sulfur autotrophic denitrifying bacteria. The full-process ammonia oxidizing bacteria convert ammonia nitrogen into nitrate nitrogen, and the sulfur autotrophic denitrifying bacteria further convert nitrate nitrogen into nitrogen gas. Both work synergistically in the same reactor to achieve deep denitrification. This invention requires no aeration and no external carbon source during operation, significantly reducing energy consumption and operating costs.

Description

Technical Field

[0001] This invention belongs to the field of wastewater biological treatment technology, specifically relating to a deep denitrification device based on full-process ammonia oxidation coupled with sulfur autotrophic denitrification and its start-up method. Background Technology

[0002] The discharge of nitrogen-containing wastewater is a significant factor contributing to eutrophication of water bodies. Currently, wastewater treatment plants widely employ traditional nitrification-denitrification biological nitrogen removal processes. However, this process requires substantial aeration and, under low C / N ratio conditions, necessitates the addition of an additional carbon source, thus increasing energy consumption and operating costs. In recent years, to overcome these problems, new biological nitrogen removal technologies have emerged, such as anaerobic ammonium oxidation (ANAO). However, a stable supply of nitrite nitrogen remains a bottleneck for ANAO, making it difficult to maintain stable performance over long periods.

[0003] Since its report in 2015, total ammonia oxidation (Comammox) has overturned the traditional understanding that nitrification requires two steps. Comammox bacteria can directly oxidize ammonia nitrogen to nitrate nitrogen and have a very high affinity for oxygen, making it a promising application in low-oxygen environments. Currently, sulfur autotrophic denitrification technology has been reported in some studies; sulfur autotrophic denitrifying bacteria can utilize reduced sulfur, such as sulfur (S...). 2- S 0 This technology uses nitrates or nitrites as electron donors to reduce them to nitrogen gas. It enables autotrophic denitrification without the need for an external carbon source.

[0004] Full-process ammonia oxidation can convert ammonia nitrogen into nitrate nitrogen, while sulfur autotrophic denitrification can convert nitrate nitrogen into nitrogen gas. The coupling of these two processes holds promise for achieving deep nitrogen removal while avoiding the high energy consumption and external carbon source requirements associated with aeration. However, coupling these processes faces numerous technical challenges, and a mature solution is currently lacking. Summary of the Invention

[0005] 1. Purpose of the invention

[0006] The purpose of this invention is to provide a deep denitrification device and its start-up method based on full-process ammonia oxidation coupled with sulfur autotrophic denitrification, which can achieve deep denitrification of wastewater in a reactor without the need for external carbon sources and aeration.

[0007] 2. Technical Solution

[0008] To achieve the objective of this invention, the technical solution adopted by this invention is as follows:

[0009] This invention provides a deep denitrification device based on full-process ammonia oxidation coupled with sulfur autotrophic denitrification. The device includes an anaerobic expanded granular sludge bed reactor containing acclimated sludge, which is enriched with both full-process ammonia oxidizing bacteria and sulfur autotrophic denitrifying bacteria.

[0010] Furthermore, the aforementioned anaerobic expanded granular sludge bed reactor is equipped with an internal circulation system.

[0011] Furthermore, the above-mentioned sludge contained both ammonia-oxidizing bacteria and sulfur-autotrophic denitrifying bacteria, with the abundance of both bacteria exceeding 5%.

[0012] Furthermore, the above-mentioned sludge contained both ammonia-oxidizing bacteria and sulfur-autotrophic denitrifying bacteria, with the abundance of both bacteria exceeding 10%.

[0013] This invention also provides a start-up method for a deep denitrification unit based on full-process ammonia oxidation coupled with sulfur autotrophic denitrification, comprising the following steps:

[0014] S1: Inoculate the reactor with sludge containing ammonia-oxidizing bacteria throughout the process, with a sludge concentration of 2000-2500 mg / L;

[0015] S2: Simulated wastewater containing ammonia nitrogen is introduced into the reactor. The initial influent ammonia nitrogen concentration is 50-60 mg / L, the hydraulic retention time is 16-24 hours, the pH in the reactor is controlled at 6.5-7.5, and the dissolved oxygen concentration is 0.1-0.5 mg / L.

[0016] S3: When the ammonia nitrogen removal rate reaches 95% or more and the nitrate nitrogen conversion rate reaches 95% or more and stabilizes, gradually increase the concentration of ammonia nitrogen in the reactor influent to 100-150 mg / L.

[0017] S4: When the reactor contains ammonia-oxidizing bacteria throughout the entire process Nitrospira The abundance of the genus reaches more than 10%, the ammonia nitrogen concentration of the influent to the reactor is kept constant at 100-150 mg / L, and sulfide is added to the influent at a concentration of 40-60 mg / L. The pH in the reactor is controlled at 7.5-8.0.

[0018] S5: As the total nitrogen removal rate gradually increases, the sulfide concentration in the reactor influent is gradually increased to 160-240 mg / L.

[0019] S6: When the removal rate of ammonia nitrogen is greater than 95% and the removal rate of total nitrogen is greater than 90%, it indicates that the ammonia oxidizing bacteria and sulfur autotrophic denitrifying bacteria have been successfully coupled and domesticated in the same reactor.

[0020] Furthermore, the above-mentioned reactor is an anaerobic expanded granular sludge bed reactor.

[0021] Furthermore, the dissolved oxygen concentration mentioned above is 0.15-0.3 mg / L.

[0022] Furthermore, the stepwise increase in step S3 above refers to increasing the ammonia nitrogen concentration in the reactor influent by 20-30 mg / L whenever the ammonia nitrogen removal rate reaches 95% or more and the nitrate nitrogen conversion rate reaches 95% or more and remains stable for 15 days.

[0023] Furthermore, after the ammonia nitrogen removal rate reaches over 95% and the nitrate nitrogen conversion rate reaches over 95% and remains stable for 15 days, the ammonia nitrogen concentration in the reactor influent is increased by 25-30 mg / L.

[0024] Furthermore, the stepwise increase in step S5 above refers to increasing the influent sulfide concentration to above 80 mg / L after the total nitrogen removal rate reaches 25% ± 5% and is maintained for more than 15 days; increasing the influent sulfide concentration to above 120 mg / L after the total nitrogen removal rate reaches 50% ± 5% and is maintained for more than 15 days; and increasing the influent sulfide concentration to above 160 mg / L after the total nitrogen removal rate reaches 75% ± 5% and is maintained for more than 15 days.

[0025] Furthermore, the stepwise increase in step S5 above refers to increasing the influent sulfide concentration to 80-120 mg / L after the total nitrogen removal rate reaches 25%±5% and is maintained for more than 15 days; increasing the influent sulfide concentration to 120-180 mg / L after the total nitrogen removal rate reaches 50%±5% and is maintained for more than 15 days; and increasing the influent sulfide concentration to 160-240 mg / L after the total nitrogen removal rate reaches 75%±5% and is maintained for more than 15 days.

[0026] 3. Beneficial effects

[0027] Compared with the prior art, the advantages of this invention are as follows:

[0028] (1) The present invention provides a deep denitrification device based on full-process ammonia oxidation coupled with sulfur autotrophic denitrification, which couples full-process ammonia oxidation and sulfur autotrophic denitrification, and can convert ammonia nitrogen into nitrogen gas without aeration, saving aeration energy consumption compared with the traditional aerobic nitrification-denitrification process.

[0029] (2) The present invention provides a deep denitrification device based on full-process ammonia oxidation coupled with sulfur autotrophic denitrification. The ammonia nitrogen is converted into nitrate nitrogen by full-process ammonia oxidation bacteria, and then the nitrate nitrogen is reduced to nitrogen gas by sulfur autotrophic denitrification bacteria to complete the denitrification. Compared with the short-process nitrification-anaerobic ammonia oxidation process, which requires control of the ratio of nitrite nitrogen and ammonia nitrogen, the operating conditions of this process are simpler.

[0030] (3) The present invention provides a deep denitrification device based on full-process ammonia oxidation coupled with sulfur autotrophic denitrification, which is suitable for denitrification treatment of wastewater with low C / N ratio. It does not require the addition of carbon source, and the electron donor is cheap and readily available sulfide. It can directly utilize the gas hydrogen sulfide or effluent sulfide generated by the reduction of sulfate by the anaerobic or hydrolysis acidification module of the wastewater treatment plant.

[0031] (4) The present invention provides a deep denitrification device based on full-process ammonia oxidation coupled with sulfur autotrophic denitrification, which couples full-process ammonia oxidation and sulfur autotrophic denitrification in one reactor. Compared with other complete denitrification processes, it saves floor space and the system has a very long sludge age, eliminating the need for sludge discharge.

[0032] (5) It is difficult for ammonia oxidizing bacteria and sulfur autotrophic denitrifying bacteria to coexist stably in a reactor. The present invention provides a start-up method for a deep denitrification device based on ammonia oxidation coupled with sulfur autotrophic denitrification. By gradually increasing the ammonia nitrogen concentration in the device, the ammonia oxidizing bacteria are enriched first, and then the sulfur concentration is added and gradually increased to enrich the sulfur autotrophic denitrifying bacteria. This achieves the synergistic effect of ammonia oxidizing bacteria and sulfur autotrophic denitrifying bacteria, and completes the deep denitrification of wastewater in a reactor. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a deep denitrification device based on full-process ammonia oxidation coupled with sulfur autotrophic denitrification. Wherein: 1 is a wastewater tank, 2 is a wastewater inlet pump, 3 is a reactor internal circulation pump, 4 is a full-process ammonia oxidation coupled with sulfur autotrophic denitrification EGSB reactor, 401 is a reactor internal circulation outlet, 402 is a constant temperature water inlet, 403 is a wastewater inlet, 404 is a gaseous hydrogen sulfide inlet, 405 is a pH / DO real-time monitoring instrument connection port, 406 is a reactor internal circulation inlet, 407 is a constant temperature water outlet, 408 is a reactor outlet, 409 is a three-phase separator, 5 is a pH / DO real-time measuring instrument, and 6 is a constant temperature circulating water bath.

[0034] Figure 2 The graph shows the total nitrogen content of the nitrogen removal process in Example 2, which involves ammonia oxidation coupled with sulfur autotrophic denitrification.

[0035] Figure 3 The graph shows the removal performance of ammonia nitrogen and total nitrogen in Example 2.

[0036] Figure 4 The graph shows the total nitrogen content of the nitrogen removal process in Example 3, which involves ammonia oxidation coupled with sulfur autotrophic denitrification.

[0037] Figure 5 The graph shows the removal performance of ammonia nitrogen and total nitrogen in Example 3. Detailed Implementation

[0038] The present invention will be further described below with reference to specific embodiments.

[0039] It should be noted that terms such as "upper", "lower", "left", "right", and "middle" used in this specification are only for clarity of description and are not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of this application.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0041] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0042] As used herein, the term “about” is used to provide for the flexibility and imprecision associated with a given term, measure, or value. Those skilled in the art can readily determine the degree of flexibility for a particular variable.

[0043] As used herein, the term “at least one of…” is intended to be synonymous with “one or more of…”. For example, “at least one of A, B, and C” explicitly includes only A, only B, only C, and combinations thereof.

[0044] Concentration, amount, and other numerical data may be presented in range format herein. It should be understood that such range format is used solely for convenience and brevity and should be flexibly interpreted to include not only the values ​​explicitly stated as the limits of the range, but also all individual values ​​or subranges encompassed within the range, as if each value and subrange were explicitly stated. For example, a range of values ​​from about 1 to about 4.5 should be interpreted to include not only the explicitly stated limits of 1 to 4.5, but also individual numbers (such as 2, 3, 4) and subranges (such as 1 to 3, 2 to 4, etc.). The same principle applies to ranges that describe only a single value, such as "less than about 4.5," which should be interpreted to include all the values ​​and ranges described above. Furthermore, this interpretation should apply regardless of the breadth of the range or characteristic described.

[0045] It should be noted that the embodiments are only used to help understand the present invention and its core principles; at the same time, for those skilled in the art, any changes made to the specific implementation methods and applications based on the ideas of the present invention are also considered to be within the scope of protection of the present invention.

[0046] In this invention, the determination of nitrite nitrogen follows GB / T 7493-1987; the determination of total nitrogen follows HJ636-2012; the determination of ammonia nitrogen follows HJ535-2009; the determination of nitrate nitrogen follows HJ / T346-2007; and 16S rDNA sequencing follows [the relevant standard / standard / etc.]. Li J , Feng Y, Wang D, Cai M, Tian Y, Pan Y, Zhang Q, Li A, Li Y, Chen X. Optimization of sulfate reduction and methanogenesis via phase separation in a two-phase internal circulation reactor for the treatment of high-sulfate organic wastewater[J]. Water research: A journal of the international water association, 2024, 260(Aug.15):1.1-1.11.

[0047] Example 1

[0048] This embodiment provides a deep denitrification device based on full-process ammonia oxidation coupled with sulfur autotrophic denitrification.

[0049] like Figure 1 As shown, the wastewater tank 1 is connected to the wastewater inlet 403 of the full-process ammonia oxidation coupled sulfur autotrophic denitrification EGSB reactor 4 via the wastewater inlet pump 2. The full-process ammonia oxidation coupled sulfur autotrophic denitrification EGSB reactor 4 is equipped with an internal circulation system. The internal circulation outlet 401 and the internal circulation inlet 406 are connected by the internal circulation pump 3 to circulate the mud-water mixture inside the reactor, ensuring uniform distribution of the microorganisms. The full-process ammonia oxidation coupled sulfur autotrophic denitrification EGSB reactor 4 is equipped with an insulation layer and a heat preservation system, which is connected to a constant temperature water inlet 402 and a constant temperature water outlet 407. The circulating water bath 6 controls the internal temperature of the reactor; the full-process ammonia oxidation coupled sulfur autotrophic denitrification EGSB reactor 4 is connected to the pH / DO real-time measuring instrument 5 through the pH / DO real-time monitoring port 405 to monitor the pH and DO (dissolved oxygen) of the full-process ammonia oxidation coupled sulfur autotrophic denitrification EGSB reactor 4 in real time; the full-process ammonia oxidation coupled sulfur autotrophic denitrification EGSB reactor 4 is equipped with a gaseous hydrogen sulfide inlet 404, which can introduce gaseous hydrogen sulfide; the top of the full-process ammonia oxidation coupled sulfur autotrophic denitrification EGSB reactor 4 is equipped with a three-phase separator 409, and the water is discharged through the reactor outlet 408.

[0050] Sulfides can be added directly to the wastewater tank 1, or gaseous hydrogen sulfide can be introduced into the full-process ammonia oxidation coupled sulfur autotrophic denitrification EGSB reactor 4 through the gaseous hydrogen sulfide inlet 404.

[0051] Example 2

[0052] This embodiment provides a start-up method for a deep denitrification device based on full-process ammonia oxidation coupled with sulfur autotrophic denitrification.

[0053] Using the apparatus described in Example 1, the EGSB reactor for full-process ammonia oxidation coupled with sulfur autotrophic denitrification is made of plexiglass and has an effective reaction zone volume of 1L.

[0054] S1: Sludge from the anoxic tank of a wastewater treatment plant of a chemical enterprise in Jiangsu Province ( Nitrospira Sludge with an abundance greater than 1% was injected into the EGSB reactor for full-process ammonia oxidation coupled with sulfur autotrophic denitrification, and the sludge concentration (MLSS) was 2000 mg / L. The time starting point was the inoculated sludge (day 0).

[0055] S2: Simulated wastewater is added to the wastewater tank. The wastewater uses ammonium chloride as the ammonia nitrogen source, with an ammonia nitrogen concentration of 50 mg / L, sodium bicarbonate concentration of 0.5 g / L, dipotassium hydrogen phosphate concentration of 0.1 g / L, calcium chloride concentration of 0.05 g / L, and magnesium chloride concentration of 0.05 g / L. The simulated wastewater is then fed into an EGSB reactor for full-process ammonia oxidation coupled with sulfur autotrophic denitrification. The hydraulic retention time (HRT) is 24 hours, the pH is maintained at 6.5-7.5, the dissolved oxygen concentration is 0.1-0.5 mg / L, the upflow velocity is 3 m / h, and the temperature is set at 30℃.

[0056] S3: After 10 days of continuous water intake, the heterotrophic bacteria almost completely disintegrated, and ammonia nitrogen removal became apparent. When the ammonia nitrogen removal rate reached over 95% and the nitrate nitrogen conversion rate reached over 95%, the influent ammonia nitrogen concentration was increased in increments of 25 mg / L to 100 mg / L. The concentration increase was achieved when the ammonia nitrogen removal rate and nitrate nitrogen conversion rate reached over 95% and remained stable for 15 days. In this example, the influent ammonia nitrogen concentration was increased to 75 mg / L on day 39 and to 100 mg / L on day 56.

[0057] S4: After 15 days of stable operation with an influent ammonia nitrogen concentration of 100 mg / L, 16S rDNA sequencing results showed that the reactor contained ammonia-oxidizing bacteria throughout the entire process. Nitrospira When the abundance of the genus reaches 10% or more, it indicates that the entire ammonia oxidation process has been successfully started. At this point, the concentration of ammonia nitrogen in the wastewater fed into the reactor is kept constant at 100 mg / L, and sodium sulfide is added to the influent. 2- The concentration was 40 mg / L, and the pH was 7.5-8.0. In this example, sodium sulfide was added on day 76.

[0058] S5: When the ammonia nitrogen removal rate remains above 95% and total nitrogen begins to be removed, it indicates that sulfur autotrophic denitrification has gradually occurred inside the reactor. When the total nitrogen removal rate reaches 25% ± 5% and is maintained for more than 15 days, the influent S... 2- The concentration was increased to 80 mg / L; after the total nitrogen removal rate reached 50% ± 5% and remained at that level for more than 15 days, the influent sulfur concentration was increased. 2- The concentration was increased to 120 mg / L; after the total nitrogen removal rate reached 75% ± 5% and remained at that level for more than 15 days, the influent sulfur concentration was increased. 2- The concentration was increased to 160 mg / L. In this example, the influent sulfur concentration was increased on days 103, 123, and 141, respectively.2- concentration.

[0059] S6: Under the conditions of an influent ammonia nitrogen concentration of 100 mg / L and a sulfide concentration of 160 mg / L, after 15 days of stable operation with an ammonia nitrogen removal rate greater than 95% and a total nitrogen removal rate greater than 90%, the acclimation of the coupled ammonia oxidation and sulfur autotrophic denitrification processes in the same reactor was completed. In this example, the acclimation was completed on day 155.

[0060] 16S rDNA sequencing was performed on sludge samples from a successfully acclimatized full-process ammonia oxidation coupled with sulfur autotrophic denitrification reactor to identify full-process ammonia oxidizing bacteria. Nitrospira Genus and sulfur autotrophic denitrifying bacteria Thiobacillus The abundances of the genera were 12.37% and 22.34%, respectively.

[0061] Starting from day 156, after 45 days of continuous flow operation, the final effluent ammonia nitrogen concentration was 0-0.53 mg / L, nitrite nitrogen concentration was 0-2.13 mg / L, and nitrate nitrogen concentration was 3.33-11.58 mg / L (e.g., ...). Figure 2 The system's ammonia nitrogen removal rate is >95%, and the average total nitrogen removal rate is >90% (e.g., Figure 3 ).

[0062] Example 3

[0063] This embodiment provides a start-up method for a deep denitrification device based on full-process ammonia oxidation coupled with sulfur autotrophic denitrification to treat wastewater with a higher concentration (higher than in Example 2).

[0064] Using the apparatus described in Example 1, the EGSB reactor for full-process ammonia oxidation coupled with sulfur autotrophic denitrification is made of plexiglass and has an effective volume of 1L.

[0065] S1: The inoculation sludge, sludge inoculation concentration, and starting point of time are all the same as in Example 2.

[0066] S2: Except for the ammonia nitrogen concentration of 60 mg / L, the composition of the simulated wastewater is the same as in Example 2.

[0067] S3: After 10 days of continuous water intake, the heterotrophic bacteria almost completely disintegrated, and ammonia nitrogen removal became apparent. When the ammonia nitrogen removal rate reached over 95% and the nitrate nitrogen conversion rate reached over 95%, the influent ammonia nitrogen concentration was increased in increments of 30 mg / L to 150 mg / L. The concentration increases were initiated when the ammonia nitrogen removal rate and nitrate nitrogen conversion rate reached over 95% and remained stable for 15 days. In this example, the influent ammonia nitrogen concentration was increased to 90 mg / L on day 38, to 120 mg / L on day 61, and to 150 mg / L on day 80.

[0068] S4: After 15 days of stable operation with an influent ammonia nitrogen concentration of 100 mg / L, 16S rDNA sequencing results showed that the reactor contained ammonia-oxidizing bacteria throughout the entire process. Nitrospira When the abundance of the genus reaches 10% or more, it indicates that the entire ammonia oxidation process has been successfully started. At this point, the concentration of ammonia nitrogen in the wastewater fed into the reactor is kept constant at 150 mg / L, and sodium sulfide is added to the influent. 2- The concentration was 60 mg / L, and the pH was 7.5-8.0. In this example, sodium sulfide was added on day 99.

[0069] S5: When the ammonia nitrogen removal rate remains above 95% and total nitrogen begins to be removed, it indicates that sulfur autotrophic denitrification has gradually occurred inside the reactor. When the total nitrogen removal rate reaches 25% ± 5% and is maintained for more than 15 days, the influent S... 2- The concentration was increased to 120 mg / L; after the total nitrogen removal rate reached 50% ± 5% and remained at that level for more than 15 days, the influent sulfur concentration was increased. 2- The concentration was increased to 180 mg / L; after the total nitrogen removal rate reached 75% ± 5% and remained at that level for more than 15 days, the influent sulfur concentration was increased. 2- The concentration was increased to 240 mg / L. In this example, the influent sulfur concentration was increased on days 122, 146, and 168, respectively. 2- concentration.

[0070] S6: Under the conditions of an influent ammonia nitrogen concentration of 150 mg / L and a sulfide concentration of 240 mg / L, after 15 days of stable operation with an ammonia nitrogen removal rate greater than 95% and a total nitrogen removal rate greater than 90%, the acclimation of the coupled ammonia oxidation and sulfur autotrophic denitrification processes in the same reactor was completed. In this example, the acclimation was completed on day 190.

[0071] 16S rDNA sequencing was performed on sludge samples from a successfully acclimatized full-process ammonia oxidation coupled with sulfur autotrophic denitrification reactor to identify full-process ammonia oxidizing bacteria. Nitrospira Genus and sulfur autotrophic denitrifying bacteria Thiobacillus The abundances of the genera were 18.19% and 16.62%, respectively.

[0072] Starting from day 178, the final effluent ammonia nitrogen concentration during continuous flow operation was 0.17-1.16 mg / L, nitrite nitrogen concentration was 0-1.27 mg / L, and nitrate nitrogen concentration was 6.15-16.11 mg / L (e.g., ...). Figure 4 The system's ammonia nitrogen removal rate is >95%, and the average total nitrogen removal rate is >90% (e.g., Figure 5 ).

Claims

1. A starting method of a deep denitrification device based on full-range ammonia oxidation coupled with sulfur autotrophic denitrification, characterized in that, The deep denitrification device includes an anaerobic expanded granular sludge bed reactor containing acclimated sludge, which is enriched with both ammonia-oxidizing bacteria and sulfur-autotrophic denitrifying bacteria. The start-up method includes the following steps: S1: Inoculate the reactor with sludge containing ammonia-oxidizing bacteria throughout the process, with a sludge concentration of 2000-2500 mg / L; S2: Simulated wastewater containing ammonia nitrogen is introduced into the reactor. The initial influent ammonia nitrogen concentration is 50-60 mg / L, the hydraulic retention time is 16-24 hours, the pH in the reactor is controlled at 6.5-7.5, and the dissolved oxygen concentration is 0.1-0.5 mg / L. S3: When the ammonia nitrogen removal rate reaches 95% or more and the nitrate nitrogen conversion rate reaches 95% or more and stabilizes, gradually increase the concentration of ammonia nitrogen in the reactor influent to 100-150 mg / L. S4: When the ammonia-oxidizing bacteria in the reactor oxidize ammonia throughout the whole process Nitrospira The abundance of the genus reached more than 10%, the ammonia nitrogen concentration of the influent water into the reactor was kept unchanged at 100-150 mg / L, sulfide was additionally added to the influent water, the sulfide concentration was 40-60 mg / L, and the pH in the reactor was controlled at 7.5-8.0; S5: As the total nitrogen removal rate gradually increases, the sulfide concentration in the reactor influent is gradually increased to 160-240 mg / L. S6: When the removal rate of ammonia nitrogen is greater than 95% and the removal rate of total nitrogen is greater than 90%, it indicates that the ammonia oxidizing bacteria and sulfur autotrophic denitrifying bacteria have been successfully coupled and domesticated in the same reactor.

2. The deep denitrification device according to claim 1, characterized in that, The anaerobic expanded granular sludge bed reactor is equipped with an internal circulation system.

3. The deep denitrification device according to claim 2, characterized in that, The sludge contained both ammonia-oxidizing bacteria and sulfur-autotrophic denitrifying bacteria, with both types of bacteria having an abundance of over 10%.

4. The startup method according to claim 3, characterized in that, The dissolved oxygen concentration is 0.15-0.3 mg / L.

5. The startup method according to claim 4, characterized in that, The stepwise increase mentioned in step S3 refers to increasing the ammonia nitrogen concentration in the reactor influent by 20-30 mg / L whenever the ammonia nitrogen removal rate reaches 95% or more and the nitrate nitrogen conversion rate reaches 95% or more and remains stable for 15 days.

6. The startup method according to claim 5, characterized in that, Once the ammonia nitrogen removal rate reaches over 95% and the nitrate nitrogen conversion rate reaches over 95% and remains stable for 15 days, increase the ammonia nitrogen concentration in the reactor influent by 25-30 mg / L.

7. The startup method according to claim 6, characterized in that, The stepwise increase mentioned in step S5 refers to increasing the influent sulfide concentration to 80-120 mg / L after the total nitrogen removal rate reaches 25%±5% and is maintained for more than 15 days; increasing the influent sulfide concentration to 120-180 mg / L after the total nitrogen removal rate reaches 50%±5% and is maintained for more than 15 days; and increasing the influent sulfide concentration to 160-240 mg / L after the total nitrogen removal rate reaches 75%±5% and is maintained for more than 15 days.

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