A strain for degrading acrylic acid and its ester wastewater and its application

Abstract

The present invention relates to a degrading strain for acrylic acid and its ester wastewater and its application. The strain belongs to Pseudomonas monteilii, with the strain code of YJY22-19 and the preservation number of CGMCC No. 25096. Its 16S rDNA gene sequence is as shown in Seq ID No: 1. The microbial agent prepared by using the strain provided by the present invention is applied to the biological treatment of acrylic acid and its ester wastewater generated in the production of coatings. It is added into the aerobic system of the AO biological treatment system at a volume percentage of 0.01-10%. The effluent COD in the acrylic acid and its ester wastewater with an initial COD of 9000 mg·L<supgt;-1< / supgt; can be reduced to below 200 mg·L<supgt;-1< / supgt> in 8 hours. By using the strain and method of the present invention, the biochemical treatment efficiency of acrylic acid and its ester wastewater can be greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of biological treatment of environmental pollutants, and specifically relates to a bacterial strain for degrading acrylic acid and its ester wastewater and an application thereof. Background Art

[0002] Acrylic acid, as an unsaturated fatty acid, is an important fine chemical raw material and intermediate. Acrylic acid, as an important organic synthesis raw material and synthetic resin monomer, is used to manufacture acrylic acid ester polymers to synthesize resins, fibers, coatings and other industrial sectors. Its production wastewater is a typical toxic petrochemical wastewater, from which acrylic acid and its ester wastewater is produced. Acrylic acid and its ester wastewater mainly includes more than ten characteristic toxic substances such as acrylic acid, methyl acrylate, formaldehyde, acrolein, toluene, n-butanol, ethyl acetate, styrene, etc. Acrylic acid and its ester wastewater has high toxicity (biodegradability <0.01), high COD (tens of thousands to hundreds of thousands of mg / L), and a wide range of pH (3-9), so its treatment has become a difficult problem to be solved in the wastewater treatment industry.

[0003] At present, the main method for treating acrylic acid and its ester wastewater is incineration. However, the incineration method has the disadvantages of large investment, high treatment cost and secondary pollution. In recent years, researchers have continuously developed new methods including catalytic wet oxidation, ion exchange fiber method, supercritical water oxidation method, photoelectron wave technology, biological method, etc. The wet catalytic oxidation method is rarely used in industry because of its key catalyst, high cost of catalyst, high requirements on water quality, and must be carried out under high temperature and high pressure conditions. The ion exchange fiber method uses a fiber as an ion exchange material, but because the ion exchange fiber is expensive and difficult to regenerate, the purification effect on wastewater is more specific, and it is difficult to industrially use acrylic acid and its ester wastewater with complex components and high COD. The supercritical water oxidation method is a method that makes a liquid under high temperature and high pressure have extremely strong oxidation ability and extensive fusion ability, but its high temperature and high pressure environment has safety hazards. The research on this technology started late, the process is immature, and there has been no report on industrial application. The technical principle of photoelectron wave technology for treating industrial wastewater is quantum mechanics, which has the characteristics of simple process and fast speed, but it has not been used in industrial wastewater treatment due to its high investment cost, little research, and immature process. The biological method refers to a treatment method that uses the metabolism of microorganisms to degrade organic matter in wastewater. This method is pollution-free and highly controllable, so it can be applied to wastewater treatment.

[0004] Although acrylic acid and its ester wastewater has the characteristics of high pollutant concentration, complex composition, high toxicity, and poor biodegradability, through long-term domestication and cultivation, microbial strains suitable for the wastewater will gradually be cultivated. At present, the Chinese patent application No. 201910097792.1 discloses an acrylic acid-degrading bacterium and its application. Escherichia coli WX degrades acrylic acid with an initial concentration of 200-3000 mg·L within 5 days. -1 The acrylic acid degradation rate can reach 95%-99.6%; Chinese patent application No. 202111586413.9 discloses Rhodococcus etheriferus ZHC and its application in the degradation of methyl acrylate. The degradation concentration of methyl acrylate by Rhodococcus etheriferus ZHC is 95-475 mg·L -1 The above patent application scheme can only degrade one type of wastewater, and the degradation rate and concentration are low, and there is no report on the degradation of multiple pollutants such as acrylic acid and its lipids. Therefore, whether to obtain a better degradation strain of acrylic acid and its esters has become one of the important tasks of researchers. Summary of the invention

[0005] The purpose of the present invention is to provide a strain for degrading acrylic acid and its ester wastewater and its application, so as to solve the problem that the existing strains for degrading acrylic acid can only degrade single-component wastewater but cannot treat mixed wastewater, and the degradation rate and concentration are both low.

[0006] To achieve the above objectives, this application is implemented through the following technical solutions:

[0007] A strain for degrading acrylic acid and its ester wastewater belongs to Pseudomonas monteri, has a strain code of YJY22-19, a preservation number of CGMCC No.25096, and a 16S rDNA gene sequence as shown in Seq ID No:1.

[0008] Furthermore, acrylic acid and its ester wastewater refers to wastewater containing one or more of acrylic acid, methyl acrylate, formic acid, ethyl acrylate, ethyl acetate, isopropyl acrylate, formaldehyde, acetic acid, toluene, acetone, acrolein, benzene or acetaldehyde.

[0009] Furthermore, a method for producing a degradation bacterial agent using a bacterial strain that degrades acrylic acid and its ester wastewater comprises the following steps:

[0010] (1) Activation of bacterial strains: taking out the stored bacterial strains and activating them at room temperature for 1-3 hours; the bacterial strain is YJY22-19;

[0011] (2) Seed culture: In a clean bench, pick the strain from the slant of a test tube and directly inoculate it into 100 ml of sterile LB liquid culture medium. Culture at 160-190 rpm and 28-35° C. for 15-22 h to prepare a seed solution.

[0012] (3) Fermentation culture: Fermentation medium is added to the fermenter, sterilized at 121° C. for 0.5 hour, and seed liquid is added at a volume ratio of 0.3%. During the fermentation process, the temperature is controlled at 28-35° C., the tank pressure is 0.03-0.05 MPa, the initial rotation speed is 160-190 rpm, the dissolved oxygen is ≧20%, and the gas-liquid ratio is 1:1; when the dissolved oxygen drops below 20%, the pH rises to 8.5, the fermentation is completed.

[0013] Furthermore, the formula of the fermentation medium is as follows by weight percentage: 0.8-1.2% glucose, 0.3-0.6% corn starch, 2.8-4.0% soybean meal, 0.3-0.7% peptone, 0.2-0.5% ammonium sulfate, 0.3-0.8% yeast powder, 0.01-0.05% manganese sulfate, and the balance is deionized water.

[0014] The invention discloses an application of a bacterial strain for degrading wastewater containing acrylic acid and its esters. The bacterial degradation agent produced by the bacterial strain for degrading wastewater containing acrylic acid and its esters is applied to degrading wastewater containing acrylic acid and its esters.

[0015] Furthermore, the COD in wastewater containing acrylic acid and its esters is 20000-100000 mg·L -1 .

[0016] Furthermore, the degradation bacteria agent is directly added into the aerobic system of the AO biological treatment system.

[0017] Furthermore, the amount of the degradation bacteria agent added is 0.01-10% of the liquid volume in the aerobic system.

[0018] The beneficial effects of the present invention are:

[0019] The bacterial agent prepared by the strain provided by the present invention is applied to the biological treatment of acrylic acid and its ester wastewater generated by the production of coatings. The above dosage is added to the aerobic system of the AO biological treatment system, and the initial COD of 9000 mg·L -1 The effluent COD of acrylic acid and its esters wastewater was reduced to 200 mg·L -1 Next, the biochemical treatment efficiency of acrylic acid and its ester wastewater can be greatly improved by using the strain and method of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the mass spectrum of acrylic acid and its lipid wastewater (headspace sampling).

[0021] Figure 2 This is the mass spectrum (headspace sampling) of the sample after the degradation of acrylic acid and its lipid wastewater by the bacterial agent in Example 3.

[0022] Figure 3 This is the mass spectrum (headspace sampling) of the blank sample after degradation of acrylic acid and its lipid wastewater in Example 3.

[0023] Figure 4 Schematic diagram of the degradation of acrylic acid by the bacterial agent in Example 4. DETAILED DESCRIPTION

[0024] The technical solution of the present application is described in detail below in conjunction with the accompanying drawings. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solution of the present invention, but cannot be construed as limiting the technical solution of the present invention.

[0025] Deposit information of the strains involved in this application:

[0026] Deposit date: June 16, 2022;

[0027] Name of depository: China National Microbiological Culture Collection Committee General Microbiology Center;

[0028] Deposit number: CGMCC No.25096;

[0029] Address of the depository: Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Chaoyang District, Beijing;

[0030] Classification name: Pseudomonas monteilii.

[0031] The Pseudomonas monteritus of the present application has a strain code of YJY22-19 and a deposit number of CGMCC No. 25096; the strain has the ability to efficiently remove acrylic acid and its ester wastewater, solves the problems of acrylic acid and its ester wastewater being difficult to treat, high energy consumption, and long time, and turns it into environmentally harmless CO 2 and H 2 O, no secondary pollution will be generated during the treatment process.

[0032] The morphological characteristics of the strain are: the colony is a single colony, opaque, slightly yellow, smooth on the surface, and neat on the edge; its 16S rDNA gene sequence is shown in Seq ID No: 1, and the 16S rDNA sequence is subjected to BLAST comparison, and the result shows that the gene sequence of the 16S rDNA of the strain has greater than 99% homology with the gene sequences of different strains of the genus Pseudomonas, and has 100% homology with the strain clearly marked as Pseudomonas monteilii.

[0033] In order to industrialize the above-mentioned strains, the applicant has determined a method for producing a degradation bacterial agent using strains that degrade acrylic acid and its ester wastewater, which includes the following steps:

[0034] (1) Activation of bacterial strains: taking out the stored bacterial strains and activating them at room temperature for 1-3 hours; the bacterial strain is YJY22-19;

[0035] (2) Seed culture: In a clean bench, pick the strain from the slant of a test tube and directly inoculate it into 100 ml of sterile LB liquid culture medium. Culture at 160-190 rpm and 28-35° C. for 15-22 h to prepare a seed solution.

[0036] (3) Fermentation culture: Fermentation medium is added to the fermenter, sterilized at 121° C. for 0.5 hour, and seed liquid is added at a volume ratio of 0.3%. During the fermentation process, the temperature is controlled at 28-35° C., the tank pressure is 0.03-0.05 MPa, the initial speed is 160-190 rpm, the dissolved oxygen is ≧20%, and the gas-liquid ratio is 1:1; when the dissolved oxygen drops below 20% and the pH rises to 8.5, the fermentation is complete;

[0037] The formula of the fermentation medium is as follows by weight: 0.8-1.2% glucose, 0.3-0.6% corn starch, 2.8-4.0% soybean meal, 0.3-0.7% peptone, 0.2-0.5% ammonium sulfate, 0.3-0.8% yeast powder, 0.01-0.05% manganese sulfate, and the balance is deionized water.

[0038] In specific application, the bacterial agent obtained by the above fermentation is added into the aerobic system at 0.01-10% of the liquid volume.

[0039] The strain of the present invention can be used to treat bacteria with an initial concentration of 5000-30000 mg·L within 20 hours. -1 The degradation rate of propylene and its esters in wastewater is over 99.13-99.87%.

[0040] The acrylic acid and its wastewater include one or more of acrylic acid, methyl acrylate, formic acid, ethyl acrylate, ethyl acetate, n-butanol, formaldehyde, acetic acid, toluene, acetone, acrolein, styrene and acetaldehyde, and its COD is 20000-100000 mg·L -1 .

[0041] The bacterial agent prepared by the strain provided by the present invention is applied to the biological treatment of acrylic acid and its ester wastewater generated by the production of coatings. The above dosage is added to the aerobic system of the AO biological treatment system, and the initial COD of 9000 mg·L -1 The effluent COD of acrylic acid and its esters wastewater was reduced to 200 mg·L-1 Next, the biochemical treatment efficiency of acrylic acid and its ester wastewater can be greatly improved by using the strain and method of the present invention.

[0042] The culture medium used in the following examples is composed as follows:

[0043] LB medium composition: Tryptone 10g L -1 , yeast powder 5g·L -1 , sodium chloride 10g·L -1 , pH 7.2; LB solid medium is the above LB medium with 1.5 wt% agar added.

[0044] Inorganic salt culture medium composition: K 2 HPO 4 0.5g·L -1 , KH 2 PO 4 0.5g·L -1 , NaCl 0.1 g·L -1 , MgSO 4 0.03g·L -1 , CaCl 2 0.02g·L -1 , FeSO 4 0.002g·L -1 , MnSO 4 0.002g·L -1 , pH 7.2.

[0045] If acrylic acid and its ester wastewater need to be added to the above two, it can be added according to specific needs, and its content is generally controlled at 5000-30000mg·L -1 .

[0046] After the culture medium is prepared, it must be sterilized in a high-pressure steam sterilizer at 121°C for 20 minutes. For the inorganic salt culture medium, acrylic acid and its ester wastewater must be added after sterilization.

[0047] Example 1

[0048] The strain was sampled from a wastewater biochemical treatment device of a Shandong Agrochemical Co., Ltd., 1 g, added to 100 mL of physiological saline sterilized at 121 ° C for 20 min, and mixed on a shaker at 160 rpm. After 30 min, it was left to stand for 1.5 h, and the supernatant was aspirated and diluted to 10 with sterile water. -3 -10 -10 times, spread it on LB solid culture medium added with acrylic acid and its ester wastewater, and culture it in a biochemical incubator at 35°C for 18 hours.

[0049] Single colonies with obvious differences on the culture dishes were selected and purified and cultured by the plate streak separation method. After three consecutive purifications, a total of 6 single strains were obtained and preserved in slants and glycerol tubes. Subsequent acrylic acid and its ester degradation experiments were carried out on the 6 selected strains in inorganic salt liquid culture medium containing acrylic acid and its ester wastewater. Finally, a strain with high acrylic acid and its ester wastewater degradation efficiency, easy cultivation and stable subculture characteristics was screened out. Its morphological characteristics are: the colonies are opaque, slightly yellow, with a smooth surface and neat edges. It was named YJY22-19.

[0050] The inventors sequenced the 16S rDNA of the strain, and the nucleotide sequence is shown in Seq ID No: 1. The 16S rDNA sequence was compared by BLAST, and the results showed that the nucleotide sequence of the 16S rDNA of the strain had greater than 99% homology with the nucleotide sequences of different strains of the genus Pseudomonas, and had 100% homology with the strain clearly marked as Pseudomonas monteilii. The strain was deposited in the General Microbiological Center of the China Microbiological Culture Collection Committee, with the deposit number CGMCC No. 25096, and was found to be alive.

[0051] Example 2

[0052] Fermentation of strains:

[0053] (1) Activation of bacterial strains: Take out the test tube of the bacterial strain stored in the slant nutrient agar medium from a 4°C refrigerator and activate it at room temperature for 1 h to 3 h.

[0054] (2) Liquid seed preparation: In a clean bench, pick the strain from the slant of a test tube and directly inoculate it into 100 ml of sterile LB liquid culture medium. Culture it at 160 rpm and 33°C for 16 h to prepare the seed solution.

[0055] (3) Fermentation: Fermentation medium accounting for 1 / 2-2 / 3 of the volume of the fermenter is added to the fermenter. After sterilization, the seed liquid is inoculated at a volume ratio of 0.2%. During the fermentation process, the temperature is controlled at 33°C, the tank pressure is 0.05MPa, the initial speed is 160rpm, the dissolved oxygen is ≧20%, and the gas-liquid ratio is 1:1. When the dissolved oxygen drops to 20% and the pH rises to 8.5, the fermentation is completed and the bacterial agent is obtained. The number of viable bacteria in the obtained bacterial agent is about 10 8 cfu / ml;

[0056] The preferred sterilization method is 121°C for 0.5 hours;

[0057] The formula of the fermentation medium is: 1.0% glucose, 0.4% corn starch, 3.0% soybean meal, 0.5% peptone, 0.4% ammonium sulfate, 0.5% yeast powder, 0.03% manganese sulfate, and the balance is deionized water.

[0058] Example 3

[0059] Bacterial agent effect verification:

[0060] The YJY22-19 seed solution obtained in step (2) of Example 2 was directly added to a flask containing 25000 mg·L -1 Acrylic acid and its ester wastewater (COD is 90000mg·L -1 ) in an inorganic salt medium with an inoculation volume ratio of 1%, and cultured at 35°C and 180rpm. A blank control without inoculation of YJY22-19 was set up. According to gas chromatography-mass spectrometry at 16h, the acrylic acid and its ester wastewater in the culture medium were 100% degraded ( Figure 2 ), mass spectrum of the residual amount of acrylic acid and its esters in the blank control wastewater ( Figure 3 ) and mass spectra of acrylic acid and its lipids ( Figure 1 ) are basically consistent, indicating that the content of acrylic acid and its lipids in the blank control remains basically unchanged.

[0061] After mass spectrometry analysis, Figure 1 In chronological order, the wastewaters containing acrylic acid and its lipids are acetaldehyde, acetone, methyl acetate, acrolein, methacrolein, benzene, isopropyl acrylate, toluene, acetic acid and formic acid.

[0062] Example 4

[0063] The degradation effect of bacterial agents on high-concentration acrylic acid and its lipid wastewater:

[0064] The YJY22-19 seed solution obtained in step (2) of Example 2 was directly added to a flask containing 30000 mg·L -1 In the inorganic salt medium of acrylic acid and its lipids, the inoculation volume ratio was 1%, and the culture was carried out at 34°C and 180rpm. A blank control without inoculation of YJY22-19 was set up for follow-up detection. At 20h, the acrylic acid and its lipid wastewater in the culture medium was 1.91mg·L -1 The degradation rate was 99.99%, and the residual amount of acrylic acid and its lipids in the blank sample remained basically unchanged ( Figure 4 ), indicating that the strain YJY22-19 provided by the present invention has an effect on 30000mg·L -1 The degradation rate of acrylic acid and its lipids can reach more than 99% in 20 hours.

[0065] Example 5

[0066] Degradation effect of bacterial agents on single wastewater of acrylic acid and its lipids:

[0067] The YJY22-19 seed solution obtained in step (2) of Example 2 was directly added to a 5000 mg / L -1 In an inorganic salt culture medium of acrylic acid or its lipids (single wastewater of acrylic acid or its lipids includes 9 samples, namely, acrolein, acrylic acid, methyl acrylate, ethyl acrylate, toluene, acetic acid, formaldehyde, acetone and acetaldehyde), the inoculation volume ratio is 1%, and the culture is carried out at 34°C and 180rpm. At the same time, blank controls without inoculation of YJY22-19 for each target wastewater are set up for follow-up detection. When measured for 24 hours, the target wastewater is not detected in the culture medium, and the degradation rate reaches 100%. The remaining amount of the target wastewater in the blank sample does not change substantially, indicating that the strain YJY22-19 provided by the present invention can effectively degrade single wastewater of the acrylic acid and its lipid wastewater species listed in this article, and can completely degrade the target wastewater with an initial concentration of 5000 mg / L within 24 hours.

[0068] Example 6

[0069] Bacterial agents are used in the treatment of paint production wastewater:

[0070] A coating production wastewater biochemical treatment device was subjected to acrylic acid and its lipid wastewater (initial content 12000mg·L -1 ) caused the system to fail to operate normally, and its outlet COD was 2636.13 mg·L -1 , ammonia nitrogen at 326.72 mg·L -1 In order to verify the treatment effect of the strain, the inventors added the bacterial agent prepared in step (3) of Example 2 into the aerobic pool at a ratio of 0.5% of the liquid volume in the aerobic pool to verify the degradation effect of acrylic acid and its lipids. The aerobic pool temperature was 32°C and the dissolved oxygen was 3.8 mg·L -1 , pH 7.32, hydraulic retention time 24h, tracking detection of acrylic acid and its lipid content in the system; the results show that the acrylic acid and its lipid content in the system increased from the initial 12000mg·L -1 Degraded to 2.69 mg·L after 20 hours -1 , the system effluent index returned to stability, and the effluent COD was 100.27 mg·L -1 , ammonia nitrogen is 0.31 mg·L -1 It can be seen that the YJY22-19 strain greatly alleviated the impact of acrylic acid and its lipids on the sewage treatment system.

[0071] Comparative Example 1

[0072] When the coating production wastewater biochemical treatment device described in Example 6 does not add the bacterial agent described in this application, the treatment concentration is 500 mg·L -1 The system can operate normally when treating acrylic acid and its lipid wastewater, with a hydraulic retention time of 24h and an effluent COD of 439.65mg·L -1 , ammonia nitrogen is 2.98 mg·L -1 , the effluent index is qualified; when receiving wastewater with higher concentration of acrylic acid and its lipids (1000-15000mg·L -1 ), the effluent COD after 24h of hydraulic retention time was 2369.81mg·L -1 , ammonia nitrogen 398.37 mg·L -1 , seriously exceeded the standard.

[0073] In order to verify the function of the bacterial agent of the present invention, the wastewater containing acrylic acid and its lipids (1000-15000 mg·L) with the same conditions as above was treated. -1 ), the YJY22-19 bacterial agent prepared in step (3) of Example 2 was added to the biochemical treatment aerobic pool at a volume ratio of 0.6% of the liquid in the aerobic pool. The aerobic pool temperature was 32°C and the dissolved oxygen was 3.8 mg·L -1 , pH 7.32; after 20 hours of treatment, acrylic acid and its lipid wastewater were not detected after gas quality testing, and COD dropped to 108.27 mg·L -1 , ammonia nitrogen is 1.33 mg·L -1 , the water output indicators are qualified.

[0074] It can be seen that after being impacted by wastewater with higher concentrations of acrylic acid and its lipids, the YJY22-19 strain can maintain the treatment effect better than the original treatment strain in the aerobic pool, and can degrade acrylic acid and its lipid wastewater in a short time without affecting the treatment effect on other pollutants, thereby achieving efficient treatment of sewage in a short time.

[0075] Comparative Example 2

[0076] Chinese patent application No. 201910097792.1 discloses an acrylic acid-degrading bacterium and its application. The Escherichia coli WX degrades acrylic acid with an initial concentration of 200-3000 mg·L within 5 days. -1 The degradation rate of acrylic acid can reach 95%-99.6%; the YJY22-19 of the present invention can degrade acrylic acid with a concentration of 5000mg·L -1 The degradation of acrylic acid was completed within 24 hours. Compared with Escherichia coli WX, the degradation rate of acrylic acid by the YJY22-19 strain of the present invention was increased by 5 times, and the degradation concentration was increased by 1.6-25 times.

[0077] Comparative Example 3

[0078] Chinese patent application No. 202111586413.9 discloses Rhodococcus etheriferus ZHC and its application in degrading methyl acrylate. The degradation concentration of methyl acrylate by Rhodococcus etheriferus ZHC is 95-475 mg·L -1 , and the YJY22-19 strain of the present invention can treat the initial concentration of 5000 mg·L -1 The methyl acrylate can be completely degraded. Compared with Rhodococcus etheriferus ZHC, the YJY22-19 strain of the present invention increases the degradation concentration of methyl acrylate by 10 times.

[0079] Through the above comparison, it can be seen that the use of the strain and method of the present invention can not only greatly increase the degradation concentration of acrylic acid and its lipids, but also achieve the purpose of simultaneously degrading acrylic acid, acrolein, methyl acrylate, ethyl acrylate and other acrylic acid lipids produced in the production process of acrylic acid. This bacterial agent and method are applied to the industrial treatment of wastewater generated by acrylic acid production, which can greatly improve the treatment efficiency and treatment cost of industrial wastewater.

[0080] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A bacterial strain for degrading acrylic acid and its ester wastewater, characterized in that: This strain belongs to Pseudomonas monteri Pseudomonas monteilii ), the strain code is YJY22-19, the deposit number is CGMCC No.25096, and its 16S rDNA gene sequence is shown in Seq ID No:

1.

2. The use of the bacterial strain for degrading acrylic acid and its ester wastewater according to claim 1 or the degrading bacterial agent produced by the bacterial strain, characterized in that: The method is applied to degrading wastewater containing acrylic acid and its esters, wherein the esters are methyl acrylate, ethyl acrylate and isopropyl acrylate.

3. The use according to claim 2, characterized in that: The COD in wastewater containing acrylic acid and its esters is 20000-100000 mg·L -1 .

4. The use according to claim 2, characterized in that: The degradation bacteria agent is directly added into the aerobic system of the AO biological treatment system.

5. The use according to claim 4, characterized in that: The addition amount of the degradation bacteria agent is 0.01-10% of the liquid volume in the aerobic system.

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