A kind of phenol efficient degradation bacterial agent, preparation and application thereof

Abstract

The invention discloses a phenol efficient degradation bacterial agent, preparation and application thereof, belonging to the field of biotechnology. The main components of the microbial agent for treating phenol wastewater are Citrobacter freundii ( Citrobacter freundi. LBQ22-2), identified by 16S rDNA sequencing Citrobacter freundii. , has been deposited in the General Microbiological Center of China Microbiological Culture Collection Committee, with a deposit number of CGMCC NO.26094 and a deposit date of November 10, 2022. The phenol-degrading bacterial agent of the present invention can grow with phenol as the sole carbon source, and can degrade 4000 mg / L phenol to less than 2 mg / L in 72 hours, with a removal rate of more than 99.5%. The bacterial preparation prepared by the present invention is added to wastewater at a mass ratio of 0.5-5‰, and has a good degradation effect on phenol-contaminated water bodies, solving the problem of difficult biodegradation of high-concentration phenol.

Description

Technical Field

[0001] The invention belongs to the field of biological wastewater treatment, and specifically relates to the preparation and application of a composite bacterial agent for treating phenol wastewater. Background Art

[0002] Phenol is an important organic chemical raw material, mainly used in the manufacture of phenolic resin, bisphenol A, pesticide fungicide salicylic acid, herbicide 2,4-D, explosive picric acid, etc. In addition, phenol is also a raw material for the manufacture of nylon, epoxy resin, coatings, paints, fragrances, synthetic detergents and plasticizers. Phenol is the main pollutant in industrial wastewater such as dyes, explosives, papermaking, polymer resins, oil refining, coal gas, coking, pharmaceuticals and textiles. Phenol is a highly toxic organic pollutant and has been included in the "blacklist" of priority pollution control in China's water environment. The arbitrarily discharged phenolic wastewater without treatment not only pollutes the ecological environment, but also causes toxic and even fatal harm to animals and plants, affecting the survival and health of organisms and humans.

[0003] At present, the treatment of phenol wastewater mainly includes physical method, chemical method, biological method and various combined methods, among which biological treatment method is an ideal method that is economical and effective and has no secondary pollution. Although phenolic compounds are a kind of biological toxic substances, many microorganisms can use phenolic compounds to grow and reproduce. The BOD / COD of phenol is 0.462, and the biodegradability is good. Therefore, microorganisms can be used to treat phenolic wastewater. Domestic and foreign scholars have carried out a lot of research work on the microbial degradation of phenol. There are more than 50 genera and more than 200 kinds of phenol-degrading bacteria, mainly including bacteria and fungi. Among them, bacteria account for more than 75%. Among the phenol-degrading bacteria, the strain of Pseudomonas sp. is the largest, followed by Bacillus sp., Alcaligens sp. and Rhodococcus sp.

[0004] In recent years, domestic and foreign scholars have conducted a lot of research on how to use microorganisms to degrade phenol-contaminated wastewater, and screened out a variety of strains, including rhizobia, Acinetobacter such as Acinetobacter calcoaceticus and Acinetobacter sp.AQ5NOL 1, Rhodococcus such as Rhodococcus erythropolis and Rhodococcusspp.CM-HZX1, Alcaligenes sp., etc. Among them, there are many microorganisms that can degrade high-concentration phenol and have good tolerance. For example, Jiang et al. isolated Candida genus from a biological pool of a pharmaceutical factory in Hubei, which can degrade 800 mg / L phenol within 72 hours. Ochrobactrum sp. isolated from an artificial wetland in Beijing by Chen Xiaohua et al. can tolerate 1300 mg / L phenol and achieve a degradation rate of 82.2% for 1000 mg / L phenol within 48 hours. Acinetobacter isolated from contaminated soil of a coking plant by Wang Tujin et al. can completely degrade phenol with an initial concentration of 1200 mg / L within 60 hours. Pseudomonas sp. isolated from pharmaceutical wastewater by Shourian et al. can degrade 1000 mg / L phenol within 85 hours. Among the many phenol-degrading bacteria discovered so far, many studies have reported that Bacillus can effectively degrade phenol. Bacillus thuringiensis J20 has a degradation rate of 88.6% for 700 mg / L phenol within 120 hours, and Bacillus brevis takes 132 hours to degrade 1000 mg / L phenol. Among them, there are few studies on the degradation of phenol in wastewater by Bacillus cereus, and the phenol degradation efficiency is also low. The strain Bacillus cereus F6 could only degrade 100 mg / L of phenol within 8 hours, while Bacillus cereus B3 needed 72 hours to degrade 800 mg / L of phenol.

[0005] The results of many studies have shown that most phenol-degrading bacteria have a slow degradation rate for phenol, and the concentration of phenol that can be degraded is mostly within 1000mg / L. There are few strains that can degrade phenol at concentrations above 1500mg / L. Phenol is a highly toxic substance. Low concentrations can denature proteins, and high concentrations can precipitate proteins, so it has direct damage to microbial cells. There are few species of degrading bacteria that can tolerate and efficiently degrade higher concentrations of phenol, and there are fewer reports. Therefore, it is particularly important to isolate and culture strains that have high tolerance and efficient degradation capabilities for high concentrations of phenol of 1500mg / L and above, and apply them to the biological treatment of high-concentration phenol wastewater. Summary of the invention

[0006] The invention aims at the problems existing in the prior art and discloses a high-efficiency phenol degradation bacterial agent, preparation and application thereof. The microbial agent prepared by using Citrobacter freundii can reduce the phenol content in phenol wastewater with a phenol concentration within 4000 mg / L by more than 99.5% through aerobic biodegradation.

[0007] The present invention is achieved in that:

[0008] A method for preparing a phenol efficient degradation bacterial agent, characterized in that the method is specifically as follows:

[0009] Step 1: solid plate culture: transfer Citrobacter freundi.LBQ22-2 to solid culture medium and culture in a 25-35°C incubator for 36 hours to activate the strain;

[0010] Step 2: Seed liquid culture: inoculate the strain activated in step 1 into liquid culture medium, and culture at 25-35°C and 150-200 rpm with shaking for 24-36 hours until the strain is in the logarithmic growth phase;

[0011] Step 3: Fermentation and expansion of the strain: inoculate the culture solution described in step 2 into the fermentation medium at a ratio of 10% for fermentation culture; obtain a concentration of 1×10 9 ~1×10 11 CFU / mL fermentation product;

[0012] Step 4: Add 20% protective agent to the fermentation product obtained in step 4 to prepare a dry powdery bacterial agent.

[0013] Furthermore, the solid culture medium in step 1 is configured as follows: 3.0 g / L beef extract; 10.0 g / L peptone; 5.0 g / L NaCl; dissolved in deionized water, pH 7-8, sterilized at 115-121°C for 15-30 min.

[0014] Furthermore, the preparation method of the liquid culture medium in step 2 is as follows: yeast extract 1-10 g / L, peptone 5-10 g / L, glucose 5-10 g / L, NH4Cl1-10 g / L, K2HPO41-10 g / L, dissolved in deionized water, pH = 7.0-8.0, sterilized at 115-121°C for 15-30 min.

[0015] Further, the culture medium for expanding the fermentation of the strains in step three is as follows: 1-5 g / L yeast extract, 5-10 g / L peptone, 5-10 g / L glucose, 1-5 g / L NH4Cl, 1-5 g / L K2HPO4, 1-5 g / L KH2PO4, 1-5 g / L trace element solution, 0.2% defoaming agent, dissolved in distilled water, pH = 7.0-8.0, sterilized at 115-121°C for 15-30 min.

[0016] Furthermore, the fermentation culture conditions in step three are: tank temperature of 37° C., tank pressure of 0.01-0.1 MPa, ventilation volume of 1:0.6-1.2, stirring speed of 150 rpm, and fermentation time of 48-72 h.

[0017] Furthermore, the protective agent formula in step five is: 35% yeast powder; 35% fish protein; 30% trace elements.

[0018] Furthermore, the formula of the trace element liquid is: MgSO4 0.5g / L; MnSO4 0.1g / L; H3BO3 0.1g / L; ZnSO4·7H2O 0.1g / L; FeSO4·7H2O 0.3g / L; pH=7.

[0019] The present invention also discloses the application of a phenol efficient degradation bacterial agent, which is achieved by the following method:

[0020] The phenol-degrading high-efficiency bacterial agent produced in the above step was added in a mass ratio of 0.5-5‰, glucose 0.5-1.5g / L (or 0.5g / L glucose and 0.2g / L phenol), tap water, pH 7-8, and cultured in a bacterial culture expansion tank at 25-35℃ with aeration (DO 2-4mg / L) for 48h to activate the bacterial strain; further, after the bacterial strain activation was completed, the bacterial density was tested, and the microscopic examination showed that it reached 1×10 9 CFU / mL means that the activation culture is completed and the activated bacterial suspension of phenol-efficient degrading bacterial agent is formed.

[0021] Furthermore, the activated bacterial suspension of the high-efficiency degradation bacterial agent was added to an inorganic salt culture medium containing 4000 mg / L phenol at a mass ratio of 5-10‰. After 72 hours of aerobic degradation (25-35°C, DO 2-4 mg / L), the phenol concentration could be reduced to below 2 mg / L, and the phenol degradation rate was greater than 99.5%.

[0022] The activated bacterial suspension of the high-efficiency degradation bacterial agent was added at 5-10‰ to a pesticide production wastewater containing 4036 mg / L phenol. After 72 hours of aerobic degradation (25-35℃, DO 2-4 mg / L), the phenol concentration can be degraded to below 2 mg / L, and the phenol degradation rate is greater than 99.5%.

[0023] The beneficial effects of the present invention compared with the prior art are:

[0024] 1. The present invention provides a highly efficient phenol degradation bacterial agent that can treat high-concentration phenol wastewater in a fully biological manner with good effect, low cost and no secondary pollution.

[0025] 2. The present invention provides a highly efficient phenol-degrading bacterial agent, which has a strong tolerance to phenol and can rapidly degrade high-concentration phenol. When the phenol concentration is ≤4000 mg / L, the phenol degradation rate is above 99.5%.

[0026] Deposit of microorganisms for patent procedure:

[0027] Deposit date: November 10, 2022

[0028] Name of depository: China National Microbiological Culture Collection Administration General Microbiology Center

[0029] Deposit number: CGMCC NO.26094

[0030] Address of the depository: No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing

[0031] Classification name: Citrobacter freundii.LBQ22-2 BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the colony morphology of Citrobacter freundi.LBQ22-2 in Example 1 of the present invention.

[0033] Figure 2 The figure shows the degradation of phenol at different concentrations over time in Example 2 of the present invention.

[0034] Figure 3 The degradation of phenol in a pesticide production wastewater over time in Example 3 of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail by enumerating examples below. It should be noted that the specific implementation described here is only used to explain the present invention and is not used to limit the present invention.

[0036] The main component of the phenol-degrading bacterial agent of the present invention is Citrobacter freundi.LBQ22-2, and the effective viable bacteria count of the microbial preparation is ≥10 10 CFU / g. The preparation method of the phenol efficient degradation bacterial agent comprises the following sequence and steps:

[0037] Step 1: solid plate culture: transfer Citrobacter freundi.LBQ22-2 to solid culture medium and culture in a 25-35°C incubator for 36 hours to activate the strain;

[0038] Step 2: Seed liquid culture: inoculate the strain activated in step 1 into liquid culture medium, and culture at 25-35°C and 150-200 rpm with shaking for 24-36 hours until the strain is in the logarithmic growth phase;

[0039] Step 3: Fermentation and expansion of the strain: inoculate the culture solution described in step 2 into the fermentation medium at a ratio of 10% for fermentation culture; obtain a concentration of 1×10 9 ~1×10 11 CFU / mL fermentation product;

[0040] Step 4: Add 20% protective agent to the fermentation product obtained in step 4 to prepare a dry powdered bacterial agent. The protective agent formula is: 35% yeast powder; 35% fish protein; 30% trace elements. The formula of the trace element liquid is: MgSO4 0.5g / L; MnSO4 0.1g / L; H3BO 30.1g / L; ZnSO4·7H2O 0.1g / L;

[0041] FeSO4·7H2O0.3g / L; pH=7.

[0042] An application of a phenol-efficient degradation bacterial agent, characterized in that in the treatment method, the wastewater is sequentially activated and cultured by the phenol-efficient degradation bacterial agent → wastewater treatment, and the specific implementation scheme is as follows:

[0043] Add phenol efficient degradation bacteria agent with a mass ratio of 0.3-1‰, glucose 0.5-1.5g / L, tap water, pH 7-8, and culture in a culture tank at 25-35℃ with aeration (DO 2-4mg / L) for 48h to activate the bacteria. Further, after the activation of the bacteria, the bacterial density was tested, and the microscopic examination showed that the bacterial density reached 1×10 9 CFU / mL means that the activation culture is completed and the activated bacterial suspension of phenol-efficient degrading bacterial agent is formed.

[0044] Adjust the wastewater to pH=7-8.5, the system inlet phenol concentration is less than 1000mg / L (or COD is less than 2000mg / L, COD is preferred), and 500mg / L COD equivalent carbon source can be added;

[0045] The implementation method of the phenol efficient degradation bacterial agent and the polyurethane filler immobilization is as follows: the activated bacterial suspension of the phenol efficient degradation bacterial agent is added into a reaction tank filled with 70% polyurethane filler in 2-3 batches according to a dosage of 10% by mass, the residence time is controlled to be 24-72 hours, sampling is performed to determine indicators such as COD and phenol, and after the phenol degradation rate is greater than 90%, the removal effect is stable for 5-10 days, and the influent phenol concentration is gradually increased with a 500 mg / L phenol concentration gradient, and the water replacement volume of each batch is 50-80%, until the influent load is the target influent phenol concentration;

[0046] When using the phenol efficient degradation bacterial agent provided by the present invention to treat phenol wastewater, a suitable biochemical treatment process can be selected according to the phenol concentration of the wastewater and the actual situation on site: when the phenol concentration is ≤4000mg / L, an aerobic biochemical process can be used; when the phenol concentration is 3500-4000mg / L, it is recommended to use the A / O process, and both the aerobic reaction tank and the anaerobic reaction tank have been inoculated with the phenol efficient degradation bacterial agent and 70% polyurethane filler. The hydraulic retention time is: when the influent phenol concentration is ≤1500mg / L, HRT 24h; when the influent phenol concentration is 1500-3500mg / L, HRT 48h; when the influent phenol concentration is 3500-4000mg / L, HRT 72h.

[0047] The following are specific examples describing the application of the phenol efficient degradation bacterial agent:

[0048] Example 1

[0049] The steps for obtaining and identifying the strain are:

[0050] Step 1: Sample collection and strain domestication

[0051] The activated sludge from the sewage treatment biochemical pool of a pesticide production company in Zhejiang Province was added to an inorganic salt culture medium with 500 mg / L phenol as the sole carbon source, the inoculation amount of the activated sludge was 10% (V / V), and the culture was carried out in a constant temperature shaker at 30°C and 150 r / min for 5 days to obtain an acclimated culture solution 1; after the culture was completed, the acclimated culture solution 1 was inoculated in an inorganic salt culture medium containing 500 mg / L phenol, the inoculation amount of the acclimated culture solution 1 was 10% (V / V), and the culture was carried out for 5 days to obtain an acclimated culture solution 2; the above acclimation culture process was repeated for continuous culture until the phenol degradation rate was greater than 90%, and the phenol-degrading bacteria acclimated culture solution was obtained.

[0052] The inorganic salt culture medium formula is: NH4Cl 0.3g / L, KH2PO4 0.5g / L, MgSO4·7H2O 0.2g / L, FeSO4·7H2O 0.02g / L, MnSO4·H2O 0.02g / L, CaCl2·6H2O 0.01g / L, pH 7.0.

[0053] Step 2: Strain Isolation and Purification

[0054] Take 1 mL of the phenol-degrading bacteria acclimation culture solution and dilute it to 10% with deionized water sterilized by high-pressure steam. -1 , 10 -2 , 10 -3 , 10 -4 , 10 -5 , 10 -6 , 10 -7 , 10 -8 , 10 -9 The bacterial suspensions of different concentrations were spread on inorganic salt solid culture medium containing 500 mg / L phenol and cultured in a constant temperature incubator at 30°C for 2-3 days. After single colonies grew on the culture medium, the largest number of single colonies with the same morphology were picked and the strains were purified by streaking for three times to obtain the target strain LBQ22-2, which was stored in a refrigerator at 4°C.

[0055] Step 3: Identification of strain LBQ22-2

[0056] The strain LBQ22-2 was inoculated on beef extract peptone solid medium and cultured in a 30°C constant temperature incubator for 48 hours. The colonies of the strain LBQ22-2 were observed to be smooth, moist, translucent, and pale white. Figure 1 ; Gram-negative rods were found under a microscope after Gram staining. 16S rDNA sequencing of strain LBQ22-2 was performed by PCR technology, and the 16S rDNA gene sequence of strain LBQ22-2 is shown in the sequence table. Using BLAST comparative analysis in the NCBI gene library, the homology between strain LBQ22-2 and Citrobacter freundii strain in the database reached 99.93%. Combined with the physiological and biochemical identification of strain LBQ22-2, strain LBQ22-2 was determined to belong to Citrobacter freundi and was named Citrobacterfreundi.LBQ22-2.

[0057] The beef extract peptone solid culture medium is prepared by adding 20 g / L agar to the beef extract peptone culture medium; the beef extract peptone culture medium comprises: 3 g beef extract, 10 g peptone, 5 g NaCl, 1 L distilled water, the pH value is adjusted to 7.5±0.2, and the culture medium is sterilized by high pressure steam at 121° C. for 20 min.

[0058] Step 4: Deposit of strain Citrobacter freundi.LBQ22-2

[0059] The strain Citrobacter freundi.LBQ22-2 was deposited in the General Microbiology Center of China Microorganism Culture Collection Administration on November 10, 2022, with the deposit number CGMCC NO.26094.

[0060] Example 2

[0061] The phenol-degrading bacterial agent provided by the present invention was inoculated into an inorganic salt medium containing 200 mg / L phenol and 1 g / L glucose at a mass ratio of 1‰ to activate the cultured bacteria. After inoculation, the culture was placed in a shaking incubator at 30°C and 150 r / min for 24 to 48 hours until the bacterial density was greater than 1×10 9 CFU / mL, forming an activated suspension of phenol-efficient degrading bacterial agent.

[0062] The activated suspension of the above-mentioned phenol-degrading efficient bacterial agent was inoculated at a 5% (V / V) inoculum into inorganic salt culture medium containing phenol concentrations of 500 mg / L, 1000 mg / L, 1500 mg / L, 2000 mg / L, 2500 mg / L, 3000 mg / L, 3500, 4000 mg / L, respectively, and cultured in a shaking incubator at 37°C. Samples were taken at different time periods to determine the residual phenol content. The results are as follows: Figure 2 As shown, at a phenol concentration of 1500 mg / L, the phenol concentration can be reduced to below 2 mg / L in 24 hours; at a phenol concentration of 2000-3500 mg / L, it can be degraded to below 2 mg / L in 48 hours; at a phenol concentration of 4000 mg / L, it can be degraded to below 2 mg / L in 72 hours.

[0063] In some embodiments, the inorganic salt culture medium may include any one of (NH4)2SO4, NH4Cl, K2HPO4, KH2PO4, NaCl, Na2SO4, MgSO4·7H2O, MnSO4·H2O, FeSO4·7H2O or a combination thereof. In Example 2, the inorganic salt culture medium formula is: NH4Cl 0.3g / L, KH2PO4 0.5g / L, MgSO4·7H2O 0.2g / L, FeSO4·7H2O 0.02g / L, MnSO4·H2O 0.02g / L, CaCl2·6H2O0.01g / L, pH 7.0.

[0064] Example 3

[0065] The phenol-degrading bacterial agent provided by the present invention is added to wastewater containing phenol. The wastewater is taken from a pesticide production company in Zhejiang Province. The COD of the wastewater raw water is 10139 mg / L, the phenol is 4036 mg / L, the initial influent phenol concentration is 500 mg / L, the pH is adjusted to 7.5, 70% polyurethane filler is added, and the phenol-degrading bacterial agent with a mass ratio of 1‰ is added. The process is aerobic aeration culture (DO 2-4 mg / L) is carried out at 30°C, and samples are taken to measure indicators such as COD and phenol. The HRT is 48 hours, the batch water change volume is 80%, the HRT is maintained for 48 hours, and the removal effect is stable for 4-6 days after the phenol degradation rate is greater than 90%. The influent phenol concentration is gradually increased to 4036 mg / L of raw water phenol according to a 500 mg / L phenol concentration gradient, the batch water change volume is 95%, the HRT is extended to 72 hours, and after 3 batches of raw water phenol 4036 mg / L are treated and the effect is stable, samples are taken at different time periods after the water change to measure the residual phenol content. The results showed that the phenol concentration was 0.42 mg / L after 56 hours of reaction, the phenol concentration in the effluent was 0.17 mg / L after 64 hours, and the effluent COD was 178 mg / L after 64 hours. Figure 3 Shown is the phenol degradation effect diagram at different reaction times at an initial phenol concentration of 4036 mg / L.

[0066] The above description is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements without departing from the principle of the present invention, and these improvements should also be regarded as within the protection scope of the present invention.

Claims

1. A Citrobacter freundii ( Citrobacter freundi )LBQ22-2, characterized in that It is deposited in the General Microbiology Center of China Culture Collection Administration, with the deposit number: CGMCCNO.26094 and the deposit date of November 10, 2022.

2. A method for preparing a phenol-degrading bacterial agent, characterized in that: The preparation method is: Step 1: solid plate culture: the Citrobacter freundii described in claim 1 ( Citrobacter freundi )LBQ22-2 was transferred to solid culture medium and cultured in an incubator at 25-35°C for 36 h to activate the strain; Step 2: Seed liquid culture: inoculate the strain activated in step 1 into liquid culture medium, and culture at 25-35°C and 150-200 rpm with shaking for 24-36 hours until the strain is in the logarithmic growth phase; Step 3: Fermentation and expansion of the strain: inoculate the culture solution in step 2 into the fermentation medium at a ratio of 10% for fermentation; Step 4: After the fermentation in step 3 is completed, add 20% protective agent to prepare a dry powder bacterial agent.

3. The method for preparing a phenol-degrading bacterial agent according to claim 2, characterized in that: The solid culture medium in step 1 is prepared as follows: 3.0 g / L beef extract, 10.0 g / L peptone, NaCl 5.0 g / L, dissolved in deionized water, pH 7-8, sterilized at 115-121°C for 15-30 min.

4. The method for preparing a phenol-degrading bacterial agent according to claim 2, characterized in that: The preparation method of the liquid culture medium in the step 2 is: yeast extract 1-10 g / L, peptone 5-10 g / L, glucose 5-10 g / L, NH4Cl1-10 g / L, K2HPO41-10 g / L, dissolved in deionized water, pH = 7.0-8.0, sterilized at 115-121°C for 15-30 min.

5. The method for preparing a phenol-degrading bacterial agent according to claim 2, characterized in that: The fermentation medium in step 3 is: yeast extract 1-5 g / L, peptone 5-10 g / L, glucose 5-10 g / L, NH4Cl1-5 g / L, K2HPO41-5 g / L, KH2PO41-5 g / L, trace element solution 1-5 mL, defoamer 0.2%, dissolved in distilled water, pH = 7.0-8.0, sterilized at 115-121 ° C for 15-30 min; the trace elements The formula of the solution is: MgSO4 0.5 g / L, MnSO4 0.1 g / L, H3BO3 0.1 g / L, ZnSO4·7H2O 0.1 g / L, FeSO4·7H2O 0.3 g / L, pH = 7; the fermentation culture conditions are: tank temperature is 37°C, tank pressure is 0.01-0.1 MPa, ventilation volume is 1:0.6-1.2, stirring speed is 150 rpm, and fermentation time is 48-72 h.

6. The method for preparing a phenol-degrading bacterial agent according to claim 2, characterized in that: The protective agent formula in step 4 is: yeast powder 35%, fish peptone 35%; trace elements 30%, the formula of the trace elements is: MgSO4 0.5g / L, MnSO4 0.1g / L, H3BO 30.1g / L, ZnSO4·7H2O0.1g / L, FeSO4·7H2O0.3g / L, pH=7.

7. A phenol-degrading bacterial agent obtained by the preparation method according to any one of claims 1 to 6.

8. Use of a phenol-degrading bacterial agent as claimed in claim 7 in degrading phenol in chemical wastewater, characterized in that: When phenol-degrading bacterial agent is added at a ratio of 0.5-5‰ to pesticide production wastewater containing 4036 mg / L of phenol, phenol can be degraded to below 2 mg / L in 48 hours, and the removal rate exceeds 99.5%.

Images