A film-forming microbial consortium with acrylonitrile degradation function, and a preparation method and application thereof

Abstract

This invention discloses a biofilm-forming microbial consortium with acrylonitrile degradation function, its preparation method, and its application. The microbial consortium consists of *Agrobacterium parakneissus*, *Burkholderia szechuanensis*, *Trichophyton spp.*, *Rhodococcus rubrum*, and *Mycobacterium tumefaciens*; the ratio of viable bacteria of *Burkholderia parakneissus*, *Burkholderia szechuanensis*, *Trichophyton spp.*, *Oligotrophomonas spp.*, and *Trichophyton spp.* is 3:1:1:1:1. This microbial consortium has a stable microbial community structure and can rapidly form a stable biofilm on the surface of biofilter packing material, exhibiting high acrylonitrile degradation efficiency. It is simple to operate, low in cost, and requires only a small amount of additional inorganic nutrients during treatment, without causing secondary pollution, making it an environmentally friendly technology. Its application prospects in the treatment of acrylonitrile-containing wastewater (gas) are broad.

Description

Technical Field

[0001] This invention belongs to the field of microbial remediation technology, and relates to a film-forming microbial alliance with acrylonitrile degradation function, its preparation method and application. Background Technology

[0002] Acrylonitrile is one of the most important monomers in the production of three major industrial synthetic materials. However, it is also a toxic substance with carcinogenic, mutagenic, and teratogenic properties. With the increasing demand and production of acrylonitrile in my country, the problem of acrylonitrile wastewater discharge is becoming increasingly serious. If not effectively treated, it will cause severe environmental pollution and seriously endanger human health. Acrylonitrile waste gas is a high-concentration, recalcitrant volatile organic compound, and how to effectively treat it has always been a challenge for acrylonitrile enterprises.

[0003] Acrylonitrile waste gas is typically treated using incineration, biological methods, and oxidation. Incineration is problematic because complete combustion of acrylonitrile wastewater is difficult, requiring large amounts of additional fuel for co-firing. This method is therefore too costly, consumes a lot of resources, and is very inefficient. Common oxidation methods include ozone catalytic oxidation, electrocatalytic oxidation, photocatalysis, and Fenton oxidation, but all are difficult to apply industrially due to secondary pollution and cost issues.

[0004] Compared to combustion and oxidation methods, biological treatment offers advantages such as milder reaction conditions, lower energy consumption, and less secondary pollution. However, the complex composition of acrylonitrile waste gas and the biotoxicity of many pollutants can significantly impact microorganisms. Furthermore, real-world operating conditions are complex, with significant fluctuations in microbial growth environments such as pH, temperature, and acrylonitrile concentration. These factors contribute to slow microbial growth and unstable treatment effectiveness.

[0005] CN101066802A relates to a novel biofilm carrier that can rapidly immobilize nitrifying bacteria, sulfate-reducing bacteria, and anaerobic methanogenic bacteria. It employs a two-phase anaerobic / anoxic-aerobic process to treat high-concentration acrylonitrile wastewater, reducing and removing sulfate, COD, and ammonia nitrogen. However, this method relies on the natural colonization of natural bacterial communities in the wastewater, where the functions of the bacterial species are unclear, functional bacteria grow and develop slowly, and the degradation rate is low and unstable.

[0006] Liu Tianlu et al. (Study on characteristic pollutants and biodegradation of wastewater from emulsion polymerization of acrylonitrile-butadiene-styrene copolymer, Petrochemical Technology and Application, 2019, 37(4): 278-282) used a laser particle size analyzer, a three-dimensional fluorescence spectrometer, a transmission electron microscope and a gas chromatography-mass spectrometry (CC-MS) instrument to analyze the particle size and composition of pollutants in ABS wastewater, identified the characteristic pollutants in the wastewater, and carried out biodegradation studies on the characteristic pollutants using the anoxic / aerobic (A / O) biofilm method. This method did not detect the bacterial strains, and the operation only used sludge for inoculation. Its bacterial community structure was relatively fragile, and the content of functional bacteria was low. It was weak in coping with changes in operating conditions and drastic fluctuations in acrylonitrile content in wastewater. The whole system was at risk of collapse when faced with drastic changes in operating conditions.

[0007] Jiang Junkang et al. (Study on Experimental Conditions for Acrylonitrile Biodegradation, Transportation Medicine, 2011, 25(6):552-554) screened and obtained acrylonitrile-degrading strains and studied their optimal degradation conditions. Topsoil samples from areas long-term contaminated with high-concentration acrylonitrile industrial wastewater were collected. After enrichment, acclimatization, and isolation, acrylonitrile-degrading strains were obtained. Factors affecting acrylonitrile degradation were investigated, and the acrylonitrile degradation rate or cell biomass was measured under corresponding conditions. The strain achieved an acrylonitrile degradation rate of 99.4%, and the strain grew well. The acrylonitrile content in the water after degradation was lower than the national emission standard. This study used a single nitrogen source method to screen single bacteria, which was cumbersome and time-consuming. Furthermore, the film-forming ability of the screened strains was not verified, and they may not be suitable for use in biofilters.

[0008] Currently, biological treatment methods are still insufficient to remove recalcitrant toxic and harmful substances, necessitating further advanced treatment measures. For example, CN102849838A discloses an advanced treatment system for acrylonitrile wastewater, comprising a vertical cylindrical fluidized bed with an aeration device and inlet pipe at the bottom, an outlet pipe at the top, suspended packing material within the fluidized bed, and an H2O2 dosing pipe and Fe2O3 dosing pipe at the bottom of the fluidized bed. 2+ The system includes a dosing line. It can further treat biologically treated wastewater to remove recalcitrant toxic and harmful substances, thereby reducing COD levels and improving effluent quality. The suspended packing material is a ring-shaped packing made primarily of polypropylene. Using this system to further treat acrylonitrile wastewater that has undergone ordinary biological treatment, the effluent COD value can be reduced to below 160 mg / L. However, this equipment still requires a dosing system; the addition of hydrogen peroxide and ferrous iron increases costs and may lead to secondary pollution.

[0009] CN108862590A describes a method that uses a complex of bacteria, including Rhodococcus, to synergistically remove acrylonitrile-containing wastewater. However, this method is limited to treating acrylonitrile-containing wastewater, and the operation involves an anaerobic biofilm reactor, requiring the construction of anaerobic equipment, resulting in high costs and complex procedures.

[0010] The complex and variable components of acrylonitrile waste gas and wastewater, along with their inherent biotoxicity, pose a severe challenge to microbial treatment systems, significantly disrupting the microbial growth environment. Therefore, the core technological challenge lies in accurately screening and cultivating highly efficient bacterial strains capable of synergistic effects under varying operating conditions, and finely adjusting their combination ratios to ensure the stability and high degradation activity of the microbial community. Furthermore, achieving efficient treatment while simultaneously considering cost-effectiveness and environmental friendliness, striving to reduce treatment costs while completely avoiding secondary pollution, is a critical technological bottleneck that urgently needs to be overcome. Summary of the Invention

[0011] To address the aforementioned technical challenges, this application proposes a composite microbial community technology for acrylonitrile-containing waste gas and wastewater. This technology achieves highly efficient biological treatment of acrylonitrile by constructing a synergistic composite microbial community. Furthermore, this technology eliminates the need for an anaerobic biofilm reactor in practical applications, offering ease of operation, low cost, and easy maintenance of microbial activity, making it particularly suitable for situations with significant fluctuations in operating conditions. This invention, using a specific carrier under real-world operating conditions, obtained a biofilm with a stable microbial community structure and high acrylonitrile degradation efficiency even under significant fluctuations in acrylonitrile concentration in the inlet gas. The main microbial species and their relative abundance were also obtained. Adding the main microorganisms, configured into a microbial alliance according to their relative abundance, to a biofilter rapidly forms a stable biofilm capable of degrading acrylonitrile on the surface of the biofilter packing material. The biofilm formed by this method exhibits stable microbial community structure and performance, high acrylonitrile degradation efficiency, and is simple to operate and low in cost. Only a small amount of inorganic nutrients need to be added during the treatment process, avoiding secondary pollution and making it an environmentally friendly technology. It has broad application prospects in the treatment of acrylonitrile-containing wastewater (gas).

[0012] One object of the present invention is to provide a film-forming microbial consortium with acrylonitrile degradation function.

[0013] Another object of the present invention is to provide a method for preparing the aforementioned microbial consortium.

[0014] Another object of the present invention is to provide the application of the aforementioned microbial consortium in the treatment of acrylonitrile-containing wastewater or acrylonitrile-containing waste gas.

[0015] To achieve the above objectives, the present invention provides a microbial consortium for the degradation of acrylonitrile, characterized in that the microbial consortium is composed of Pedobacter ginsengiterrae, Burkholderia zhejiangensis sp.nov., Commonas terrae., Rhodococcus ruber, and Mycobacterium phlei, and the ratio of their viable bacteria is 2:1:1:3:3.

[0016] The species *Pedobacter ginsengiterrae* has been deposited at the China Center for Type Culture Collection in Wuhan, China, with accession number CCTCC AB 2020352 and deposit date of December 17, 2020.

[0017] Burkholderia zhejiangensis, named Burkholderia zhejiangensis sp.nov., strain number OP-1T, is now deposited at the China Center for Type Culture Collection in Wuhan, China, with accession number CCTCC AB2010354T and deposit date of June 7, 2010.

[0018] The terrestrial tufted bacterium, named *Comamonas terrae*, strain number AS1P, is deposited at the China Center for Type Culture Collection (CCTCC) in Wuhan, China, with accession number CCTCC AB 2020304 and deposit date of November 23, 2020.

[0019] Rhodococcus ruber, strain number ZM07, is deposited at the China Center for Type Culture Collection in Wuhan, China, with accession number CCTCC AB 2019217 and deposit date of June 17, 2019.

[0020] Mycobacterium phlei, now deposited at the China Center for Type Culture Collection in Wuhan, China, with accession number CCTCC AB 2015128 and deposit date of March 30, 2015.

[0021] On the other hand, the present invention provides a method for preparing the aforementioned microbial consortium, the method comprising:

[0022] Agrobacterium tumefaciens, Burkholderia leuciscus, Trichomonas terrestris, Rhodococcus rubrum and Mycobacterium tumefaciens were inoculated into sterile LB liquid medium and cultured in shake flasks at 25℃~30℃ in the dark until the late logarithmic growth stage, and were used as seed culture.

[0023] The above seed liquid was inoculated into sterile nutrient fermentation medium at a volume ratio of 4-6%, and cultured at 25℃-30℃ until the bacterial OD600 reached 1.5 to obtain fermentation liquid.

[0024] The above fermentation broth is compounded, or further concentrated or dried as needed, to obtain a microbial consortium.

[0025] Further, the nutrient fermentation medium comprises 5.0 g / L yeast powder, 10.0 g / L sodium chloride, and 10.0 g / L peptone; or the nutrient fermentation medium comprises 5.0 g / L yeast powder, 10.0 g / L sodium sulfate, and 10.0 g / L peptone, with a pH of 7.2 to 7.6.

[0026] The microbial alliance of this invention mainly utilizes the synergistic effect of five degrading bacteria to remove acrylonitrile organic matter, thereby providing a highly efficient, economical, and environmentally friendly method for treating acrylonitrile waste gas.

[0027] In one specific embodiment of the present invention, the microbial consortium for acrylonitrile degradation is composed of fermentation broths of five strains: Agrobacterium tumefaciens, Burkholderia zedoaria OP-1T, Trichomonas terrestris AS1P, Rhodococcus rubrum ZM07, and Mycobacterium tumefaciens, mixed uniformly in a live cell ratio of 2:1:1:3:3, with the OD600 of the bacterial agent reaching 1.5.

[0028] On the other hand, the present invention also provides the application of the aforementioned microbial consortium in the degradation of acrylonitrile organic matter, including for the degradation of acrylonitrile-containing waste gas and / or wastewater in biofilters.

[0029] The present invention also provides a method for degrading acrylonitrile organic matter, the method comprising: inoculating the aforementioned microbial consortium into a sample to be treated containing acrylonitrile organic matter, and culturing it for a period of time, thereby achieving the degradation of acrylonitrile organic matter.

[0030] Furthermore, the microbial alliance is inoculated into the sample to be treated containing acrylonitrile organic matter in the form of a biofilm.

[0031] According to a specific embodiment of the present invention, the formation process of the biofilm includes: adding the microbial alliance into a biofilter containing packing material, and then flooding it with acrylonitrile-containing wastewater for a two-week aeration and biofilm formation operation; wherein the microbial alliance is a mixed bacterial agent, the bacterial agent has an OD600 of 1.5, and the amount of bacterial agent added is 4-6% of the wastewater volume.

[0032] The specific process of cultivation includes: observing the formation of obvious biofilm on the packing material, continuously running the biofilter for 1 week to 1 month with inorganic salt culture medium as the circulating liquid, a circulating liquid flow rate of 10 L / min, and a circulating liquid pH controlled at 5.0-9.0, to achieve the degradation of acrylonitrile organic matter.

[0033] Furthermore, when a significant biofilm formation was observed on the packing material, acrylonitrile-containing waste gas was introduced into the biofilter while using an inorganic salt culture medium as the circulating liquid.

[0034] In one specific embodiment of the present invention, the temperature of the circulating fluid is between 10 and 30°C.

[0035] Preferably, the acrylonitrile-containing waste gas uses air as the carrier gas, and the acrylonitrile concentration in the carrier gas is 5–200 mg / m³. 3 .

[0036] In one specific embodiment of the present invention, the residence time of the waste gas in the biological filter is 50s, and the gas flow rate is 1-100L / S.

[0037] In one specific embodiment of the present invention, the inorganic salt culture medium comprises 0.5 g / L K2HPO4 and 0.5 g / L MgSO4.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] (1) This invention constructs a microbial alliance through artificial means, creating a microbial alliance with high degradation efficiency, stable microbial community structure, and strong shock resistance, capable of operating normally under conditions of large fluctuations in pH, temperature, and acrylonitrile concentration. It can utilize acrylonitrile in waste gas and / or wastewater to meet its own needs, thereby achieving the purpose of degrading acrylonitrile without secondary pollution.

[0040] (2) This invention obtains microbial alliances in situ by sampling under real working conditions, reveals their community structure using bioinformatics, and artificially constructs microbial alliances based on this, so that the microbial alliances are adapted to real working conditions, have high degradation efficiency, and have simple processes. Microorganisms have broad prospects for engineering applications.

[0041] (3) The microbial consortium constructed in this invention is applicable to both acrylonitrile-containing waste gas and wastewater. In practical applications, it does not require an anaerobic biofilm reactor, the feeding process is simple, the cost is low, and the activity of the microorganisms is easy to maintain. Especially under fluctuating operating conditions, the microorganisms can still maintain a high growth rate and acrylonitrile treatment efficiency. Results from practical applications show that this microbial community has an acrylonitrile degradation efficiency of over 95%.

[0042] (4) This invention fully utilizes the life activities of microorganisms to degrade various pollutants, including acrylonitrile. Furthermore, acrylonitrile and other pollutants provide the carbon and nitrogen sources necessary for microbial growth, reproduction, and other life activities. No additional chemical reagents are required during the pollutant degradation process; other nutrients needed for microbial growth flow within the device in the form of a circulating liquid. The pollutant degradation process is simple, convenient, and highly effective. Examples demonstrate that the microbial alliance constructed in this invention has a high and stable degradation efficiency for wastewater and waste gas with fluctuating acrylonitrile concentrations. Detailed Implementation

[0043] To enable those skilled in the art to better understand the technical solutions in this application, the present invention will be further described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0044] Example 1

[0045] In this embodiment, the preferred composition and content of the LB liquid culture medium are: 5.0 g / L yeast extract, 10.0 g / L sodium sulfate, 10.0 g / L peptone, and pH = 7.2-7.6.

[0046] Step 1: Activate the members of the Microbial Alliance, namely Agrobacterium tumefaciens, Burkholderia zedoaria OP-1T, Trichophyton spp. AS1P, Rhodococcus rubrum ZM07, and Mycobacterium tumefaciens, on LB solid medium for 16-48 h. Then, transfer each strain to sterile LB liquid medium and activate them in a shake flask at 25℃~30℃ in the dark for 16-48 h until the late logarithmic growth stage. This is used as the initial seed culture.

[0047] Step 2: Place the initial seed culture of the above 5 strains into sterile LB liquid medium at an inoculation rate of 4-6%, and ferment at 25℃-30℃ and 150rpm until the OD600 of the bacterial culture reaches 1.5 to obtain the fermentation grade I seed culture.

[0048] Step 3: Centrifuge the bacterial solution obtained in Step 2, resuspend it in physiological saline to prepare a bacterial solution with OD600 = 1.5, and mix it with the viable counts of Agrobacterium tumefaciens, Burkholderia leptospira OP-1T, Trichophyton spp. AS1P, Rhodococcus rubrum ZM07 and Mycobacterium tumefaciens in a ratio of 2:1:1:3:3 to obtain a mixed bacterial solution, which is the microbial alliance;

[0049] Add the microbial consortium (4-6% by volume) to a biofilter filled with packing material, and then flood it with acrylonitrile-containing wastewater for a two-week aeration and biofilm formation operation.

[0050] Step 4: After Step 3, a significant biofilm formation was observed on the packing material. An inorganic salt culture medium was used as the circulating liquid, with the following composition: K₂HPO₄ 0.5 g / L, MgSO₄ 0.5 g / L. Acrylonitrile-containing waste gas mixed with air was used as the carrier gas, with an acrylonitrile concentration of 30.0 mg / m³. 3 The biofilter was operated continuously for one month under the following conditions: gas flow rate of 1-100 L / s, gas residence time in the biofilter of 50 s, circulating liquid flow rate of 10 L / min, and circulating liquid pH controlled at 5.0-9.0. During this period, the circulating liquid temperature was recorded every three days. The concentration of acrylonitrile in the inlet and outlet gas phases of the device was determined according to the gas chromatography method for the determination of acrylonitrile in exhaust gas from stationary pollution sources of the Ministry of Ecology and Environment of the People's Republic of China (standard number: HJ / T 37-1999). It was found that the circulating liquid temperature fluctuated between 10 and 30 ℃ during the month, and the acrylonitrile degradation and removal rate in the gas phase was not affected by the circulating liquid temperature, with an average removal rate of 95.3%.

[0051] Waste gas, wastewater, and circulating liquid come into contact with the packing surface in the circulating tank, and acrylonitrile is adsorbed and degraded by the microorganisms on the packing surface membrane.

[0052] Example 2

[0053] In this embodiment, the preferred composition and content of the LB liquid culture medium are: 5.0 g / L yeast extract, 10.0 g / L sodium sulfate, 10.0 g / L peptone, and pH = 7.2-7.6.

[0054] Step 1: Activate the members of the Microbial Alliance, namely Agrobacterium tumefaciens, Burkholderia zedoaria OP-1T, Trichophyton spp. AS1P, Rhodococcus rubrum ZM07, and Mycobacterium tumefaciens, on LB solid medium for 16-48 h. Then, transfer each strain to sterile LB liquid medium and activate them in a shake flask at 25℃~30℃ in the dark for 16-48 h until the late logarithmic growth stage. This is used as the initial seed culture.

[0055] Step 2: Place the initial seed culture of the above 5 strains into sterile LB liquid medium at an inoculation rate of 4-6%, and ferment at 25℃~30℃ and 150rpm until the OD600 of the bacterial culture reaches 1.5 to obtain the fermentation grade I seed culture.

[0056] Step 3: Centrifuge the bacterial solution obtained in Step 2, resuspend it in physiological saline to prepare a bacterial solution with OD600 = 1.5, and mix it with the viable counts of Agrobacterium tumefaciens, Burkholderia leptospira OP-1T, Trichophyton spp. AS1P, Rhodococcus rubrum ZM07 and Mycobacterium tumefaciens in a ratio of 2:1:1:3:3 to obtain a mixed bacterial solution, which is the microbial alliance;

[0057] Add the microbial consortium (4-6% by volume) to a biofilter filled with packing material, and then flood it with acrylonitrile-containing wastewater for a two-week aeration and biofilm formation operation.

[0058] Step 4: After Step 3, a significant biofilm formation was observed on the packing material. An inorganic salt culture medium was used as the circulating liquid, with the following inorganic salt concentrations: K₂HPO₄ 0.5 g / L, MgSO₄ 0.5 g / L. Acrylonitrile-containing waste gas was mixed with air as the carrier gas, with an acrylonitrile concentration of 5.0 mg / m³. 3 The biofilter was operated continuously for one week under the following conditions: gas flow rate of 1-100 L / s, gas residence time in the biofilter of 50 s, circulating liquid flow rate of 10 L / min, and circulating liquid pH controlled at 5.0-9.0. This simulated a low acrylonitrile inlet concentration. Based on the determination of acrylonitrile in the exhaust gas from stationary pollution sources by gas chromatography (standard number: HJ / T 37-1999) of the Ministry of Ecology and Environment of the People's Republic of China, the acrylonitrile concentration in the inlet and outlet gas phases of the device was determined. The acrylonitrile degradation and removal rate in the gas phase reached 97%. Step 5: After step 4, the acrylonitrile concentration in the carrier gas was increased to 200.0 mg / m³. 3 The biofilter was operated continuously for one week under the following conditions: gas flow rate of 1-100 L / s, gas residence time in the biofilter of 50 s, circulating liquid flow rate of 10 L / min, and circulating liquid pH controlled at 5.0-9.0. This simulated a high acrylonitrile inlet concentration after starvation. According to the determination of acrylonitrile in the exhaust gas of stationary pollution sources by gas chromatography (standard number: HJ / T37-1999) of the Ministry of Ecology and Environment of the People's Republic of China, the acrylonitrile concentration in the inlet and outlet gas phases of the device was determined. The acrylonitrile degradation and removal rate in the gas phase reached 99.3%.

[0059] In steps four and five, the waste gas, wastewater, and circulating liquid come into contact with the packing surface in the circulating tank, and the acrylonitrile is adsorbed and degraded by the microorganisms on the packing surface membrane.

Claims

1. A film-forming microbial consortium with acrylonitrile degradation function, wherein the microbial consortium is composed of Pedobacter ginsengiterrae, Burkholderia zhejiangensis sp.nov., Commonas terrae., Rhodococcus ruber, and Mycobacterium phlei; In the aforementioned microbial alliance, the ratio of viable counts of the *Agrobacterium tumefaciens*, *Burkholderia zedoaria*, *Trichophyton spp.*, *Rhodococcus rubrum*, and *Mycobacterium tumefaciens* is 2:1:1:3:

3. in, The *Gastrobacterium* species mentioned is *Gastrobacterium* with accession number CCTCC AB 2020352; The *Burkholderia leuciscus* strain mentioned is *Burkholderia leuciscus* with accession number CCTCC AB 2010354T. The *Teratomys teratomys* species is *Teratomys teratomys* with accession number CCTCC AB 2020304. The Rhodococcus species mentioned is the Rhodococcus species with accession number CCTCC AB 2019217; The *Mycobacterium tumefaciens* mentioned is the *Mycobacterium tumefaciens* with the accession number CCTCC AB 2015128.

2. The method for preparing the microbial consortium according to claim 1, the method comprising: Agrobacterium tumefaciens, Burkholderia leuciscus, Trichomonas terrestris, Rhodococcus rubrum and Mycobacterium tumefaciens were inoculated into sterile LB liquid medium and cultured in shake flasks at 25℃~30℃ in the dark until the late logarithmic growth stage, and were used as seed culture. The above seed liquid was inoculated into sterile nutrient fermentation medium at a volume ratio of 4-6%, and cultured at 25℃-30℃ until the bacterial OD600 reached 1.5 to obtain fermentation liquid. The above fermentation broth is compounded, or further concentrated or dried as needed, to obtain a microbial consortium.

3. The preparation method according to claim 2, characterized in that, The nutrient fermentation medium comprises 5.0 g / L yeast extract, 10.0 g / L sodium chloride, and 10.0 g / L peptone, with a pH of 7.2–7.6; or the nutrient fermentation medium comprises 5.0 g / L yeast extract, 10.0 g / L sodium sulfate, and 10.0 g / L peptone, with a pH of 7.2–7.

6.

4. The application of the microbial consortium of claim 1 in the degradation of acrylonitrile organic matter.

5. The application according to claim 4, characterized in that, This includes acrylonitrile used in biofilters to degrade acrylonitrile-containing waste gas and / or wastewater.

6. A method for degrading acrylonitrile organic matter, characterized in that, The method includes: inoculating the microbial consortium described in claim 1 into a sample to be treated containing acrylonitrile organic matter, and culturing it for a period of time to achieve the degradation of acrylonitrile organic matter.

7. The method according to claim 6, characterized in that, The method includes: adding the microbial consortium to a biofilter filled with packing material, and then flooding it with acrylonitrile-containing wastewater for a two-week aeration and biofilm formation operation; wherein the microbial consortium is a mixed bacterial agent with an OD600 of 1.5 and the amount of bacterial agent added is 4-6% of the wastewater volume. A significant biofilm formation was observed on the packing material. The biofilter was continuously operated for 1 week to 1 month with inorganic salt culture medium as the circulating liquid, a circulating liquid flow rate of 10 L / min, and the circulating liquid pH controlled at 5.0-9.0 to achieve the degradation of acrylonitrile organic matter.

8. The method according to claim 7, characterized in that, When a significant biofilm formation is observed on the packing material, acrylonitrile-containing waste gas is introduced into the biofilter while using an inorganic salt culture medium as the circulating liquid.

9. The method according to claim 7, characterized in that, The temperature of the circulating liquid is between 10 and 30°C, and the inorganic salt culture medium consists of K2HPO4 0.5 g / L and MgSO4 0.5 g / L.

10. The method according to claim 8, characterized in that, The residence time of the waste gas in the biological filter is 50 seconds, and the gas flow rate is 1-100 L / s.