A method for strengthening pyridine degradation and synchronous short-term denitrification by combining functional bacteria with MABR technology

Abstract

The present invention discloses a method for strengthening pyridine degradation and synchronous short-term denitrification by combining functional bacteria with MABR process. According to the ecological niche characteristics of biofilm in MABR process, the present invention sequentially forms biofilms with rhizobium NJUST18 inoculum of pyridine degradation functional strain, nitrifying sludge and denitrifying functional strain Paracoccus denitrifying NJUST53 inoculum. The rhizobium in the aerobic layer of the biofilm formed after biofilm formation uses pyridine as the only carbon source and nitrogen source for growth, and the nitrifying bacteria use the ammonia nitrogen produced by pyridine degradation to carry out the nitrification process. The denitrifying Paracoccus in the anoxic layer uses the nitrite nitrogen / nitrate nitrogen and pyridine produced in the nitrification process to carry out denitrification. In addition, the activity of nitrite oxidizing bacteria is suppressed by controlling the aeration pressure and the pH of the influent, thereby achieving the strengthening of pyridine degradation and synchronous short-term denitrification.

Description

Technical Field

[0001] The invention belongs to the technical field of biological treatment of environmental organic pollutants, and relates to a method for strengthening the simultaneous short-term denitrification of pyridine degradation by combining functional bacteria with a MABR process, and specifically relates to a method for strengthening the simultaneous short-term denitrification of volatile pyridine degradation by combining two functional strains with a MABR process. Background Art

[0002] As a typical nitrogen-containing heterocyclic compound, pyridine is widely used in industries such as pharmaceutical manufacturing, agriculture, printing and dyeing industry, coking industry and explosives production, generating a large amount of pyridine wastewater with low C / N specific point. Biological treatment is considered to be a low-cost and environmentally friendly wastewater treatment technology. Among them, anaerobic treatment is usually limited by its low removal rate and poor process stability, while the traditional aerobic treatment process for the treatment of volatile pyridine wastewater is not only energy-intensive, but also causes disgusting odor and serious air pollution. In addition, as pyridine degrades, the nitrogen on the pyridine ring will eventually be released into the water environment in the form of ammonia nitrogen, causing secondary pollution.

[0003] Membrane Aerated Biofilm Reactor (MABR) is a highly efficient sewage treatment technology that combines membrane technology and biofilm technology. The unique microbial hierarchical structure and electrochemical gradient formed by the biofilm in the MABR system can simultaneously exist in aerobic, anoxic and anaerobic zones, providing favorable conditions for synchronous short-range nitrification and denitrification. In addition, MABR has the advantages of bubble-free aeration and high oxygen utilization efficiency, thus solving the problem of volatile organic compounds being easily volatilized in traditional aerobic treatment processes.

[0004] In recent years, the application of MABR in wastewater treatment has received extensive attention. However, most MABRs are currently used in wastewater with high nitrogen characteristics and low toxicity (such as municipal wastewater, livestock wastewater, etc.). For example, Wang Biwei et al. used a membrane aerated biofilm reactor to treat domestic sewage (Wang Biwei. Research on the treatment of domestic sewage with a membrane aerated bioreactor [D]. Huazhong University of Science and Technology, 2018.), Zhang Han et al. used a membrane aerated biofilm reactor to treat anaerobic fermentation broth of cow dung (Zhang Han. Struvite crystallization combined with a membrane aerated biofilm reactor to treat anaerobic fermentation broth of cow dung [D]. Harbin Institute of Technology, 2018.), and Sun Qiuhui et al. used a membrane aerated biofilm reactor to treat black and smelly river water (Sun Qiuhui. Research on the effect of bubble MABR technology on oxygenation and quality improvement of black and smelly water bodies and its optimization design [D]. Tianjin University, 2018.). The application of MABR in highly toxic chemical wastewater is still limited. Summary of the invention

[0005] In view of the pollution of pyridine volatilization caused by aeration and oxygen supply in the pyridine aerobic biological treatment system and the difficulty in denitrification of low carbon-nitrogen ratio wastewater, the present invention provides a method for strengthening pyridine degradation and synchronous short-range denitrification by combining functional bacteria with MABR process.

[0006] The technical solution of the present invention is as follows:

[0007] The method of combining functional bacteria with MABR process to enhance pyridine degradation and synchronize short-range denitrification, the specific steps are:

[0008] (1) After the expansion of rhizobium NJUST18, the liquid bacteria are centrifuged, washed to remove residual nutrients, and centrifuged again to obtain the bacterial sediment as the bacterial inoculum. The bacterial sediment is then injected into the MABR reactor along with the pyridine wastewater influent. After maintaining the internal circulation for 3 to 4 days, continuous flow water is introduced. A dense biofilm is gradually formed on the fiber membrane in the reactor. Finally, the bacterial inoculum that settles at the bottom of the reactor is discharged from the system.

[0009] (2) After the pyridine removal rate of the reactor is stabilized, the nitrified sludge after acclimatization with ammonia nitrogen wastewater is injected into the MABR reactor. After maintaining the internal circulation for 3 to 4 days, continuous flow of water is carried out, and a new layer of biofilm is gradually covered on the biofilm. Finally, the nitrified sludge settled at the bottom of the reactor is discharged from the system;

[0010] (3) After the expansion of Paracoccus denitrificans NJUST53, the liquid bacteria were centrifuged, washed to remove residual nutrients, and centrifuged again to obtain bacterial sediment as bacterial inoculum. After the removal rate of pyridine and ammonia nitrogen in the reactor was stable, the bacterial sediment was injected into the MABR reactor along with the influent. After maintaining the internal circulation for 3 to 4 days, continuous flow of water was carried out, and a new layer of biofilm was gradually covered on the biofilm. Finally, the bacterial inoculum settled at the bottom of the reactor was discharged from the system;

[0011] (4) By controlling the aeration pressure and inlet pH value at 0.02±0.005MPa and 8.0-8.2 respectively, MABR was used to achieve simultaneous short-term denitrification and pyridine degradation.

[0012] In step (1), the rhizobium NJUST18 was deposited in China Center for Type Culture Collection (CCTCC) on March 28, 2013, with the deposit number of CCTCC NO: M 2013110, and the deposit address is Wuhan University, Wuhan City, Hubei Province, China, and has been fully disclosed in Chinese Patent ZL201310553435.4.

[0013] In step (3), the denitrifying Paracoccus NJUST53 has been deposited in the China Center for Type Culture Collection (CCTCC) on March 2, 2022, and the strain collection number is CCTCC NO: M 2022178. The storage address is Wuhan University, Wuhan City, Hubei Province, China, and has been fully disclosed in Chinese patent application 202210608230.0.

[0014] In a specific embodiment of the present invention, in step (1), the specific method for expanding the culture of rhizobium bacillus NJUST18 is: inoculating rhizobium bacillus NJUST18 into an inorganic salt medium MSM supplemented with 1 g / L pyridine, and culturing on a shaking table for more than 96 hours.

[0015] In a specific embodiment of the present invention, in step (3), the specific method for expanding the culture of Paracoccus denitrificans NJUST53 is: inoculating Paracoccus denitrificans NJUST53 into an inorganic salt medium MSM supplemented with 1 g / L glucose, and culturing on a shaking table for more than 96 hours.

[0016] In a specific embodiment of the present invention, the composition of the inorganic salt medium MSM is: Na2HPO4·2H2O 3.5g / L, KH2PO4 1g / L, (NH4)2SO4 500mg / L, MgCl2·6H2O 100mg / L, Ca(NO3)2·4H2O

[0017] 50mg / L, trace element SL-4 1.0ml / L; the composition of trace element SL-4 is: EDTA 0.5g / L, FeSO4·7H2O 0.2g / L, ZnSO4·7H2O 0.001g / L, MnCl2·4H2O 0.003g / L, H3BO4 0.03g / L, CoCl2·6H2O 0.02g / L, CuCl2·2H2O 0.001g / L, NiCl2·6H2O 0.002g / L, Na2MoO4·2H2O0.003g / L.

[0018] In a specific embodiment of the present invention, in step (1), (2) or (3), the centrifugal speed is 8000 rpm, the centrifugal time is 10 min, and the cleaning solution is a phosphate buffer solution.

[0019] The method of strengthening pyridine degradation and synchronous short-range denitrification by combining functional bacteria with MABR process of the present invention can strengthen pyridine degradation and nitrogen removal in a single reactor. Pyridine degradation functional strain rhizobium NJUST18, nitrifying sludge and denitrifying Paracoccus NJUST53 are used as inoculants, biofilm is formed according to the microbial niche, and the synergistic effect between pyridine degrading bacteria, nitrifying bacteria and denitrifying bacteria is utilized to achieve efficient degradation of pyridine and efficient removal of nitrogen.

[0020] Compared with the prior art, the present invention has the following significant advantages:

[0021] The present invention combines two functional strains with MABR for the first time. Each functional strain lives in its own ecological niche, which enhances the degradation of pyridine and the removal of nitrogen. -3 ·d -1 The pyridine can be completely removed, the TN removal rate is as high as 95.24%, and the TOC removal rate is as high as 94.88%. The invention also effectively solves the problems of pyridine volatility in traditional aerobic processes, difficulty in denitrification of low carbon ratio wastewater, and large footprint of traditional aerobic-anoxic processes, and has industrial practicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the effect of the symbiotic system of two functional strains and nitrifying sludge on the degradation and denitrification of pyridine when using the traditional oxygen supply mode. (a) is the change graph of pyridine concentration, (b) is the change graph of trinitrogen concentration, and (c) is the TN and TOC removal rates.

[0023] Figure 2 It is a schematic diagram of a special device for treating pyridine wastewater.

[0024] Figure 3 This is a diagram showing the removal effect of pyridine using two functional strains combined with the MABR process.

[0025] Figure 4 This is a graph showing the changes in the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the effluent of the MABR process combined with two functional strains.

[0026] Figure 5 This is a diagram showing the TOC removal effect of two functional strains combined with MABR technology.

[0027] Figure 6 This is a diagram showing the removal effect of TN using two functional strains combined with the MABR process.

[0028] Biological deposit information

[0029] The rhizobium NJUST18 described in the present invention was deposited in the China Center for Type Culture Collection (CCTCC) on March 28, 2013, with the deposit number of CCTCC NO: M 2013110, and the deposit address is Wuhan University, Wuhan City, Hubei Province, China, and has been fully disclosed in Chinese Patent ZL201310553435.4.

[0030] The denitrifying Paracoccus NJUST53 described in the present invention has been deposited in the China Center for Type Culture Collection (CCTCC) on March 2, 2022, and the strain preservation number is CCTCC NO: M 2022178. The preservation address is Wuhan University, Wuhan City, Hubei Province, China, and has been fully disclosed in Chinese patent application 202210608230.0. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with specific embodiments and drawings.

[0032] In the following examples and comparative examples, the compositions of the culture medium and simulated wastewater used are as follows:

[0033] The components of the inorganic salt medium MSM are: Na2HPO4·2H2O 3.5g / L, KH2PO4 1g / L, (NH4)2SO4500mg / L, MgCl2·6H2O 100mg / L, Ca(NO3)2·4H2O 50mg / L, trace elements SL-4

[0034] 1.0ml / L.

[0035] The components of pyridine simulated wastewater are: pyridine 300 mg / L, NaHCO3 2000 mg / L, MgSO4·7H2O0.8873 g / L, KCl 0.35 g / L, CaCl2 0.20 g / L, FeCl3 0.03 g / L, and trace element SL-4 10 mL / L.

[0036] Trace element SL-4 composition: EDTA 0.5g / L, FeSO4·7H2O 0.2g / L, ZnSO4·7H2O 0.001g / L, MnCl2·4H2O 0.003g / L, H3BO4 0.03g / L, CoCl2·6H2O 0.02g / L, CuCl2·2H2O 0.001g / L, NiCl2·6H2O 0.002g / L, Na2MoO4·2H2O 0.003g / L.

[0037] Example 1

[0038] Preparation of two functional strains and sludge inoculum

[0039] (1) Preparation of inoculum of rhizobium NJUST18: Rhizobium NJUST18 was inoculated into an inorganic salt medium MSM supplemented with 1 g / L pyridine. After shaking culture for 96 hours, the bacterial solution was centrifuged at 8000 × g for 10 minutes to obtain a bacterial sediment with a dry weight of about 2 g as the inoculum.

[0040] (2) Cultivation of nitrifying sludge: The sludge was taken from the SBR activated sludge reactor that treats ammonia nitrogen wastewater. After more than a year of operation, good results were achieved. The sludge was centrifuged at 8000×g for 10 minutes, and the sludge sediment with a dry weight of about 2g was used as the inoculum.

[0041] (3) Preparation of inoculum of Paracoccus denitrificans NJUST53: Paracoccus denitrificans NJUST53 was inoculated into an inorganic salt medium MSM supplemented with 1 g / L glucose. After shaking culture for 96 hours, the bacterial solution was centrifuged at 8000 × g for 10 minutes, and the bacterial sediment with a dry weight of about 2 g was obtained as the inoculum.

[0042] Comparative Example 1

[0043] Effect of the symbiotic system of two functional strains and nitrifying sludge on pyridine degradation and denitrification using traditional oxygen supply mode

[0044] The strain and sludge inoculum were prepared according to Example 1, and the obtained bacterial sediment and sludge sediment were resuspended in a sterile inorganic salt liquid culture medium, centrifuged, and washed three times. The bacterial cells and sludge were mixed and resuspended in a sterile liquid inorganic salt culture medium MSM to obtain bacterial sludge (control OD600 to be about 1.7).

[0045] Prepare pyridine simulated wastewater with pyridine as the only carbon and nitrogen source. Add the above-mentioned bacterial sludge into the pyridine simulated wastewater, with an inoculation amount of 5%, a hydraulic retention time of 48 hours, and conventional aeration at 35°C using an air compressor with a maximum aeration pressure of 0.05MPa and the same number of startups as MABR. Monitor the concentration changes of pyridine, total organic carbon (TOC) and trinitrogen during the culture process.

[0046] Figure 1 The symbiotic system of two functional strains and nitrifying sludge shows the effect of pyridine degradation and denitrification when using the traditional oxygen supply mode. (a) is the change of pyridine concentration, (b) is the change of tri-nitrogen concentration, and (c) is the TN and TOC removal rate. Figure 1 It can be seen that the symbiotic system of two functional strains and nitrifying sludge cannot achieve complete degradation of pyridine within 48 hours. The average removal rate of pyridine is only 68.23%, and the average removal rates of TN and TOC are 17.18% and 63.88%, respectively. In addition, a large amount of pyridine volatilizes during aeration, causing secondary pollution. The above results show that the symbiotic system of two functional strains and nitrifying sludge has poor effects on pyridine degradation and denitrification when using the traditional oxygen supply mode, and cannot meet the process requirements of pyridine wastewater treatment.

[0047] Example 2

[0048] 1. MABR startup process

[0049] The present invention combines the pyridine degradation strain rhizobium NJUST18 and the denitrifying bacteria Paracoccus denitrifying NJUST53 with the MABR process. The efficient removal ability of the functional bacterial agent combined with the ecological niche (aerobic zone and anoxic zone) of the MABR biofilm enables the process to achieve efficient removal of pyridine and the nitrogen released by it.

[0050] MABR reactor operation and design parameters: The reactor is a cylindrical MABR reactor made of organic glass with an effective volume of 2.0L. The membrane assembly in the MABR reactor is made of 850 hollow fiber membranes sealed by glue injection, with a total membrane area of ​​up to 0.93m 2 . The hollow fiber membrane is made of polydimethylsiloxane (PDMS), with a length of 0.35m, an outer diameter of 1.0mm and an inner diameter of 0.5mm. The air pressure inside the membrane is provided by an air compressor and controlled by an exhaust valve. The aeration pressure ranges from 0.01 to 0.05MPa, and the hydraulic retention time is maintained at 48 hours. Synthetic wastewater is injected into the bottom of the reactor through a peristaltic pump. The reactor is equipped with a circulation pump to achieve uniform mixing of pollutants in the MABR. In addition, the reactor is equipped with a jacketed circulating water bath for insulation, and the temperature is adjusted to 35±1℃.

[0051] like Figure 2 As shown, a special device for treating pyridine wastewater mainly includes: a bioreactor 1, a pyridine wastewater tank 2, an air compressor 8 and a water outlet tank 13; wherein the bioreactor 1 is composed of a bottom mud discharge area 5, a water inlet area 4, a membrane aeration component 7 and a top water outlet area 12; the pyridine wastewater tank 1 is connected to the water inlet area 4 of the bioreactor 1 through a water inlet pump 3, the air compressor 8 is connected to the membrane aeration component 7 of the bioreactor 1 through a ball valve 9 and a pressure gauge 10, and the water outlet tank 13 is connected to the top water outlet area 12 of the bioreactor 1. In addition, a circulating pump 14 is provided to form a circulation to enhance the mixing of the inlet water and the mass transfer efficiency of the pollutants, so as to improve the treatment effect of the bioreactor 1.

[0052] like Figure 2 As shown, the DO value of the bioreactor 1 is measured using a dissolved oxygen meter at the top of the membrane aeration assembly 7, and the dissolved oxygen of the bioreactor 1 is controlled by adjusting the air compressor 8 and the ball valve 9; the pH value of the bioreactor 1 is measured using a pH meter at the top of the membrane aeration assembly 7. The circulation and reflux of the bioreactor 1 are regulated by a reflux pump 14. The measurement samples of the bioreactor 1 are the inlet water in the inlet tank 1 and the outlet water in the outlet tank 13.

[0053] 2. Film forming process:

[0054] (1) Preparation of rhizobium NJUST18 inoculum: Rhizobium NJUST18 was inoculated into an inorganic salt medium MSM supplemented with 1 g / L pyridine. After 96 hours of shaking culture, the bacterial solution was centrifuged at 8000×g for 10 minutes to obtain a bacterial sediment with a dry weight of about 2 g as the inoculum. It was then injected into the MABR reactor along with the pyridine simulated wastewater influent. After maintaining the internal circulation for 3 days, continuous flow inflow was performed, and a dense biofilm was gradually formed on the fiber membrane. Finally, the bacterial inoculum that settled at the bottom of the reactor was discharged from the system.

[0055] (2) After the pyridine removal rate of the reactor is stabilized, the nitrified sludge that has been domesticated in Example 1 is injected into the reactor. After maintaining the internal circulation for 3 days, water is continuously introduced, and a new layer of biofilm is gradually covered on the biofilm. Finally, the nitrified sludge inoculum that has settled at the bottom of the reactor is discharged from the system.

[0056] (3) According to the method in Example 1, after the expansion of Paracoccus denitrificans NJUST53, the liquid bacteria were centrifuged, the residual nutrients were washed and removed, and the bacterial sediment obtained by centrifugation was used as the bacterial inoculum. After the removal rate of pyridine and ammonia nitrogen in the reactor was stable, the bacterial sediment was injected into the reactor along with the influent water. After the internal circulation was maintained for 3 days, the water was continuously inflowed, and a new biofilm was gradually covered on the biofilm. Finally, the bacterial inoculum settled at the bottom of the reactor was discharged from the system.

[0057] The startup status of the bioreactor is determined by taking water samples from the bioreactor inlet and outlet every day and conducting water quality tests; when the pyridine removal rate of the bioreactor reaches more than 80%, it is confirmed that the device has been successfully started.

[0058] 3. Reactor Operation

[0059] Pyridine simulated wastewater was prepared as the influent of the MABR reactor, and the initial concentration of pyridine was 300 mg / L. During the operation, the hydraulic retention time was 48 h and the temperature was 35±1°C. The reaction operation was divided into 5 stages. In the first stage, the aeration pressure was 0.01 MPa and the influent pH was 7; in the second stage, the aeration pressure was 0.03 MPa and the influent pH was 7; in the third stage, the aeration pressure was 0.02 MPa and the influent pH was 7; in the fourth stage, the aeration pressure was 0.02 MPa and the influent pH was 8; in the fifth stage, the aeration pressure was 0.05 MPa and the influent pH was 8.

[0060] The performance of MABR at different stages Figure 3-6As shown in the figure, when the aeration pressure is 0.01MPa, the removal rate of pyridine is maintained at 87-91%, the effluent ammonia nitrogen concentration is maintained at 24-28mg / L, and the concentrations of nitrite nitrogen and nitrate nitrogen are almost zero. When the aeration pressure is increased to 0.03MPa, the pyridine removal rate is 100%, the effluent ammonia nitrogen and nitrite nitrogen concentrations are almost zero, and the nitrate nitrogen concentration is maintained at 11-19mg / L. In order to achieve the simultaneous nitrification and denitrification process, the aeration pressure is reduced to 0.02Mpa. In this stage, the system still has a 100% removal rate for pyridine, the nitrate nitrogen concentration is significantly reduced, and the TN removal rate is 83.76±2.1%. In order to further improve the denitrification rate, the influent pH value is increased to 8 to achieve short-range denitrification. In this stage, the effluent ammonia nitrogen and nitrate nitrogen concentrations are further reduced, the TN removal rate is increased to 93.24±2.45%, and the TOC removal rate is as high as 94.88±0.39%. When the aeration pressure was increased to 0.05 MPa, the nitrate nitrogen concentration increased significantly during this stage and was maintained at 35-41 mg / L.

[0061] The results showed that too low aeration pressure made it difficult to completely remove pyridine, and the remaining pyridine was toxic to nitrifying bacteria, making it difficult for them to carry out the nitrification process. Too high aeration pressure would release more dissolved oxygen into the anoxic layer of the biofilm, thereby inhibiting the related enzyme activities of denitrifying bacteria in the anoxic layer. In stage IV, the higher influent pH inhibited the activity of NOB, allowing the ammonia nitrogen oxidation process to proceed further, while also saving carbon sources for the denitrification process, thereby achieving short-term nitrification and denitrification.

[0062] The mechanism of pyridine degradation and simultaneous short-range denitrification in MABR: pyridine diffuses into the aerobic layer of the biofilm and is degraded by pyridine-degrading bacteria to release ammonia nitrogen and small molecular organic matter. + -N produces NO2 under the action of ammonia-oxidizing bacteria and inhibited nitrite-oxidizing bacteria in the aerobic layer of the biofilm - / NO3 - The generated NO2 - / NO3 - And pyridine / small molecule organic matter produces N2 and CO2 under the action of denitrifying bacteria in the anoxic layer.

[0063] The present invention combines two functional strains with MABR, and each functional strain lives in its own ecological niche, which enhances the degradation of pyridine and the efficient removal of nitrogen. MABR can achieve complete degradation of pyridine, and the removal rates of TN and TOC are as high as 93.24% and 94.88%, respectively. However, the average removal rate of pyridine by the symbiotic system of two functional strains and nitrifying sludge is only 68.23%, and the average removal rates of TN and TOC are 17.18% and 63.88%, respectively. In addition, MABR effectively solves the problems of pyridine volatility, low oxygen utilization rate, difficulty in denitrification of low carbon ratio wastewater, and large footprint of traditional aerobic-anoxic processes in traditional aerobic processes, and has industrial practicality.

Claims

1. The method of strengthening pyridine degradation and synchronous short-range denitrification by combining functional bacteria with MABR technology. It is characterized in that The specific steps are: (1) After the expansion of rhizobium NJUST18, the liquid bacteria are centrifuged, washed to remove residual nutrients, and centrifuged again to obtain the bacterial sediment as the bacterial inoculum. The bacterial sediment is then injected into the MABR reactor along with the pyridine wastewater influent. After maintaining the internal circulation for 3 to 4 days, continuous flow water is introduced. A dense biofilm is gradually formed on the fiber membrane in the reactor. Finally, the bacterial inoculum that settles at the bottom of the reactor is discharged from the system. (2) After the pyridine removal rate of the reactor is stabilized, the nitrified sludge after acclimatization with ammonia nitrogen wastewater is injected into the MABR reactor. After maintaining the internal circulation for 3 to 4 days, continuous flow of water is carried out, and a new layer of biofilm is gradually covered on the biofilm. Finally, the nitrified sludge settled at the bottom of the reactor is discharged from the system; (3) After the expansion of Paracoccus denitrificans NJUST53, the liquid bacteria were centrifuged, washed to remove residual nutrients, and centrifuged again to obtain bacterial sediment as bacterial inoculum. After the removal rate of pyridine and ammonia nitrogen in the reactor was stable, the bacterial sediment was injected into the MABR reactor along with the influent. After maintaining the internal circulation for 3 to 4 days, continuous flow of water was carried out, and a new layer of biofilm was gradually covered on the biofilm. Finally, the bacterial inoculum settled at the bottom of the reactor was discharged from the system; (4) By controlling the aeration pressure and inlet pH value at 0.02±0.005MPa and 8.0-8.2 respectively, MABR was used to achieve simultaneous short-term denitrification and pyridine degradation.

2. The method according to claim 1, It is characterized in that In step (1), the rhizobium NJUST18 was deposited in China Center for Type Culture Collection on March 28, 2013, with the deposit number of CCTCC NO: M2013110.

3. The method according to claim 1, It is characterized in that In step (3), the denitrifying Paracoccus NJUST53 has been deposited in the China Center for Type Culture Collection on March 2, 2022, and the strain collection number is CCTCC NO: M2022178.

4. The method according to claim 1, It is characterized in that In step (1), the specific method for expanding the culture of rhizobium bacillus NJUST18 is: inoculating rhizobium bacillus NJUST18 into an inorganic salt medium MSM supplemented with 1 g / L pyridine, and culturing on a shaking table for more than 96 hours.

5. The method according to claim 1, It is characterized in that In step (3), the specific method for expanding the culture of Paracoccus denitrificans NJUST53 is: inoculating Paracoccus denitrificans NJUST53 into an inorganic salt culture medium MSM supplemented with 1 g / L glucose, and culturing on a shaking table for more than 96 hours.

6. The method according to claim 1, It is characterized in that The composition of inorganic salt medium MSM is: Na 2 HPO 4 ·2H 2 O3.5g / L, KH 2 PO 4 1g / L, (NH4) 2 SO 4 500mg / L, MgCl 2 6H 2 O 100mg / L, Ca(NO 3 ) 2 ·4H 2 O 50mg / L, trace element SL-4 1.0ml / L; the composition of trace element SL-4 is: EDTA 0.5g / L, FeSO 4 7H 2 O 0.2g / L, ZnSO 4 7H 2 O 0.001g / L, MnCl 2 ·4H 2 O 0.003g / L, H 3 BO 4 0.03g / L, CoCl 2 6H 2 O 0.02g / L, CuCl 2 ·2H 2 O 0.001g / L, NiCl 2 6H 2 O 0.002g / L, Na 2 MoO 4 ·2H 2 O0.003g / L.

7. The method according to claim 1, It is characterized in that In step (1), (2) or (3), the centrifugal speed is 8000 rpm, the centrifugal time is 10 min, and the cleaning solution is a phosphate buffer solution.

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