Polymer emulsion for biodegrading chlorine-containing volatile organic compounds, catalytic system and biodegradation method

Abstract

The invention discloses a polymer emulsion for biodegrading chlorine-containing volatile organic compounds, a catalytic system and a biodegradation method. The polymer emulsion is an emulsion system obtained by ultrasonically mixing amphiphilic block polymers in an insoluble C10-C14 carbon alkane solvent and an inorganic salt culture medium aqueous solution, the emulsion system is an oil-in-water system, and the block polymer is a polymer 1. The polymer emulsion prepared from the amphiphilic polymer 1 can effectively increase the contact surface between microorganisms and pollutants, so that the degradation rate can be greatly improved when the CVOCs are biodegraded in a water phase, and the polymer emulsion system is used for degrading the CVOCs in the water phase for the first time.

Description

Technical Field

[0001] The invention belongs to the technical field of treating chlorinated volatile organic pollutants, and specifically relates to a polymer emulsion, a catalytic system and a biodegradation method for biodegrading chlorinated volatile organic matter. Background Art

[0002] Volatile organic compounds (VOCs) refer to organic pollutants with a boiling point between 50 and 260°C at room temperature and atmospheric pressure. Chlorinated volatile organic compounds (CVOCs), as a typical representative of industrial source VOCs, have the characteristics of large emissions, high toxicity, and strict control. Their safe and low-carbon treatment is one of the difficult problems in air pollution control in the chemical industry.

[0003] At present, biological methods can use the metabolic activities of microorganisms to convert CVOCs into substances such as CO2, H2O, and HCl. They are suitable for treating large-flow, low-concentration CVOCs waste gas and have obvious comprehensive advantages in safety and economy. However, the hydrophobicity of CVOCs will greatly increase the mass transfer resistance in the system, and its high toxicity will also inhibit the activity of microorganisms.

[0004] Due to some problems that arise during the biological treatment process, current research is mainly focused on improving the driving force of CVOCs mass transfer by introducing a non-aqueous phase into the system as an absorption medium. According to the form of existence, the existing non-aqueous phase can be divided into liquid and solid non-aqueous phases. Liquid non-aqueous phases are represented by silicone oil and ionic liquids. Silicone oil only serves as a temporary storage reservoir and can effectively buffer the fluctuation of pollutant load. The use of silicone oil and ionic liquids to enhance mass transfer has problems such as difficult separation and recovery, high consumption, and easy foaming. Solid non-aqueous phases are represented by organic polymers such as silicone masterbatches. Although silicone masterbatches have the advantages of being cheap, easy to obtain, and having good biocompatibility, their mass transfer enhancement effect is still weaker than that of liquid non-aqueous phases. In summary, existing research only promotes the gas-liquid diffusion process of CVOCs by increasing their solubility in non-aqueous phases, and does not enhance the liquid-solid (biofilm) transfer process.

[0005] In the two-phase biocatalytic process, functional emulsifiers can emulsify the water and organic phases into a uniform emulsion, increase the interface area, and enhance the contact between the biocatalyst and the pollutant. In addition, the emulsifier is amphiphilic. The hydrophilic segment carries a positive charge that can electrostatically attract Gram-negative bacteria. The hydrophobic segment introduces pyridine groups that can bind to CVOCs through non-covalent bonds, shortening the mass transfer path. The formation of polymer emulsions can effectively increase the contact surface between microorganisms and CVOCs, thereby promoting the biodegradation of CVOCs. Therefore, this simple method can be used to increase the biodegradation rate of CVOCs. Summary of the invention

[0006] In view of the disadvantages of traditional single-phase biodegradable CVOCs, such as large mass transfer resistance, high toxicity to microorganisms, and large contact area between the two phases after the addition of a non-aqueous phase, the purpose of this application is to provide a polymer emulsion, a catalytic system and a biodegradation method for biodegrading chlorinated volatile organic compounds.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A polymer emulsion for biodegrading chlorinated volatile organic compounds, the polymer emulsion is an emulsion system obtained by ultrasonically mixing an amphiphilic block polymer in an immiscible C10-C14 carbon alkane solvent and an inorganic salt culture medium aqueous solution, the emulsion system is an oil-in-water system, and the block polymer is polymer 1. A product formed by a nucleophilic addition reaction of 4-pyridinemethylamine and methacryloyl chloride is used as monomer 1, the monomer 1 is first polymerized on a chain transfer agent RAFT-CTA, and then polymerized with NIPAM and methacrylamide propyltrimethylammonium chloride under the action of an initiator to obtain the polymer 1.

[0009] Furthermore, the C10-C14 alkane solvent is selected from n-dodecane, and its volume ratio to the inorganic salt culture medium aqueous solution is 0.5-2:1, preferably 1.5:1; the concentration of the block polymer in the polymer emulsion is 10-50 mg / mL, preferably 20 mg / mL.

[0010] Furthermore, the final concentration of the inorganic salt culture medium aqueous solution is as follows: KH2PO4 0.5 g / L, NaHPO4·12H2O 0.5 g / L, (NH4)2SO4 2 g / L, MgSO4·7H2O 0.1 g / L, K2HPO4 0.5 g / L, MnSO4·H2O 0.13 mg / L, CuSO4 0.03 mg / L, Na2MoO4·7H2O 0.2 mg / L, (NH4)6Mo7O 24 4H2O 0.347mg / L, the solvent is deionized water.

[0011] Furthermore, the preparation method of the block polymer is as follows, based on parts by weight:

[0012] 1) dissolving 2.5±0.5 parts of monomer 1, 0.02±0.005 parts of AIBN and 0.17±0.03 parts of chain transfer agent RAFT-CTA in DMF solvent, stirring under N2 atmosphere protection, stirring in an oil bath at 70-80° C. for 2-4 days, so that monomer 1 is first polymerized on the chain transfer agent RAFT-CTA; wherein the monomer 1 is prepared by a nucleophilic addition reaction of 4-pyridinemethylamine and methacryloyl chloride;

[0013] 3) Weigh 6.1±0.5 parts of NIPAM, 8±0.5 parts of methacrylamidopropyltrimethylammonium chloride (MAPTAC) and 0.1±0.05 parts of AIBN and dissolve them in DMF. Stir under N2 atmosphere and then transfer to the solution in step 1). Continue stirring in an oil bath at 70-80°C for 1-3 days. Finally, remove the solvent by suction to obtain polymer 1.

[0014] Furthermore, the preparation method of the monomer 1 comprises the following steps, in parts by weight: 4-pyridinemethylamine, triethylamine and methacryloyl chloride are stirred in ethyl acetate solvent under room temperature water bath conditions for reaction for 3-5 hours, after the reaction is completed, saturated saline is used as an extractant for extraction and separation, the organic layer is dried over anhydrous sodium sulfate to remove moisture, then filtered to remove the organic solvent, and finally the mixture is separated by column chromatography, and the monomer 1 is obtained after filtration. The volume ratio of the 4-pyridinemethylamine to triethylamine is 1:0.4-1.0, preferably 1:0.5-0.6; the volume ratio of the 4-pyridinemethylamine to methacryloyl chloride is 1:0.8-1.2, preferably 1:0.9-1.0.

[0015] The present invention also provides a catalytic system for biodegrading chlorinated volatile organic compounds, the catalytic system comprising the polymer emulsion and the catalyst of the present invention, and the bacterial body obtained by expanding the culture of Pseudomonas putida CB-Y is used as the catalyst. Pseudomonas putida CB-Y is deposited in China Center for Type Culture Collection, address: Wuhan University, China, 430072, deposit date: August 27, 2024, deposit number: CCTCC M 20241856, and classification name: Pseudomonas putida CB-Y. The nucleotide sequence of Pseudomonas putida CB-Y is shown in SEQ ID NO.1.

[0016] Furthermore, the concentration of the block polymer in the catalytic system is 10-50 mg / mL, preferably 20 mg / mL, and the OD of the catalyst bacteria is 600 Value = 0.5-4, preferably 1-2.

[0017] Furthermore, the method for preparing the catalyst cell comprises the following steps:

[0018] S1 solid culture: Pseudomonas putida CB-Y was inoculated into R2A solid culture medium and cultured at room temperature for 20-30 hours to obtain activated bacteria; the final concentration of the R2A solid culture medium was as follows: yeast powder 0.5 g / L, soluble starch 0.5 g / L, MgSO4 0.05 g / L, tryptone 0.5 g / L, glucose 0.5 g / L, sodium pyruvate 0.375 g / L, KH2PO4 0.45 g / L, agar 20 g / L, pH 7, and the solvent was deionized water;

[0019] S2 expansion culture: Use an inoculation loop to pick the bacteria obtained in step S1 and inoculate them into R2A liquid culture medium. Shake and culture at 100-200 rpm for 10-20 hours at room temperature. When entering the logarithmic growth phase, centrifuge, wash, and redisperse in an aqueous solution of an inorganic salt culture medium.

[0020] The invention also discloses a method for biodegrading chlorinated volatile organic compounds. Chlorinated volatile organic compounds are added to the catalytic system of the invention to form a catalytic degradation system. The chlorinated volatile organic compounds are cultured under shaking at 100-200 rpm at room temperature to degrade the chlorinated volatile organic compounds.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) The polymer emulsion droplets formed by ultrasonication of polymer 1 in n-dodecane and inorganic salt culture medium are relatively small, and the droplets are evenly and densely distributed. When the emulsion system is used for biodegradation of chlorobenzene, the degradation rate and dechlorination rate are improved.

[0023] 2) The polymer emulsion prepared by the amphiphilic polymer 1 of the present invention can effectively increase the contact surface between microorganisms and pollutants, thereby greatly improving the degradation rate when biodegrading CVOCs in an aqueous phase. It is the first time that a polymer emulsion system is used to degrade CVOCs in an aqueous phase. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Fluorescence microscope photograph of the emulsion system used.

[0025] Figure 2 This is a fluorescence microscope photograph of the emulsion system after staining with Nile red dye, where the red area is the organic phase.

[0026] Figure 3 The degradation rate of chlorobenzene after 10 hours of degradation by emulsion-microorganism coupling system with different oil-water ratios.

[0027] Figure 4 Chloride ion content in the aqueous phase after chlorobenzene degradation by emulsion-microorganism coupling system with different oil-water ratios for 10 hours.

[0028] Figure 5 The degradation rate of chlorobenzene after 10 hours of degradation by the emulsion-microorganism coupling system with different emulsion concentrations.

[0029] Figure 6 The chloride ion content in the aqueous phase after the emulsion-microorganism coupling system with different emulsion concentrations degraded chlorobenzene for 10 hours.

[0030] Figure 7The curves of the degradation of chlorobenzene by different catalytic degradation systems Emulsion 10-13 in Example 3 over time are shown.

[0031] Figure 8 It is the chloride ion content in the water phase after different catalytic degradation systems Emulsion 10-13 in Example 3 of the invention degraded chlorobenzene for 13 hours.

[0032] Fig. 9 The curves of the degradation of chlorobenzene by the emulsion-microorganism coupling system Emulsion 14 in Example 4 and the catalytic degradation system Emulsion 13 in Example 3 over time are shown.

[0033] Fig.10 It is the chloride ion content in the aqueous phase after the emulsion-microorganism coupling system Emulsion 14 in Example 4 and the catalytic degradation system Emulsion 13 in Example 3 degraded chlorobenzene for 13 hours.

[0034] Fig.11 The curves of the degradation of chlorobenzene by the emulsion-microorganism coupling system Emulsion 17 in Example 4 and the catalytic degradation system Emulsion 13 in Example 3 over time are shown.

[0035] Fig.12 It is the chloride ion content in the aqueous phase after the emulsion-microorganism coupling system Emulsion 17 in Example 4 and the catalytic degradation system Emulsion 13 in Example 3 degraded chlorobenzene for 13 hours.

[0036] Fig.13 The degradation rate of chlorobenzene after 10 hours of degradation by different organic phase emulsion-microorganism coupling systems.

[0037] Fig.14 Chloride ion content in the aqueous phase after chlorobenzene was degraded by different organic phase emulsion-microorganism coupling systems for 10 hours. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0039] Blank example 1:

[0040] The polymer 1 of the present invention is prepared according to the following method:

[0041] S1: In a room temperature water bath, 10.65 mL of 4-pyridinemethylamine, 6 ml of triethylamine and 15 ml of ethyl acetate were mixed evenly, and a solution of methyl methacryloyl chloride in ethyl acetate (prepared by dissolving 10 ml of methyl methacryloyl chloride in 20 ml of ethyl acetate) was slowly dripped into the mixture while stirring, and the reaction was continued with stirring for 4 hours. After the reaction was completed, saturated saline was used as an extractant for extraction twice, and the upper organic phase was retained. Anhydrous Na2SO4 was added to the upper organic phase to remove excess water, and then the organic solvent was removed by suction. Finally, the mixture was separated by column chromatography (the eluent was ethyl acetate- at a volume ratio of 200:1), and monomer 1 was obtained after suction filtration. The reaction equation is as follows:

[0042]

[0043] S2: Weigh 2.5g of monomer 1 prepared from S1, 0.0233g of azobisisobutyronitrile (AIBN) and 0.17g of chain transfer agent (RAFT-CTA) and dissolve them in 25ml of N,N-dimethylformamide (DMF). Stir the above solution under N2 atmosphere for 2h to remove the air in the bottle, then stir in an oil bath at 75°C for 3 days to polymerize the monomer 1 material on the chain transfer agent (RAFT-CTA). The reaction equation is as follows:

[0044]

[0045] Secondly, 6.1g of NIPAM, 8g of methacrylamide propyl trimethylammonium chloride (MAPTAC) and 0.1g of AIBN were weighed and dissolved in 15ml of DMF, stirred for 2h under N2 atmosphere, and then transferred to the above solution with a syringe, and continued to stir in an oil bath at 75°C for 2 days. Finally, the organic solvent was removed by filtration to obtain polymer 1. The reaction equation is as follows:

[0046]

[0047] The polymer 1 prepared in Blank Example 1 was dispersed in 400 μl of deionized water, and then 600 μl of n-dodecane was added and ultrasonicated to form an emulsion system. The fluorescence microscope photo of the emulsion system is shown in FIG. Figure 1 As shown in the figure, the fluorescence microscope photo of the emulsion system after being stained with Nile red dye is shown in Figure 2 shown. Figure 1 The emulsion is uniform in size and has regular circular shapes. The particle size formed is relatively small, about 20 microns in diameter, which can effectively increase the interfacial area of ​​the two phases. Figure 2 We can see that the emulsion is oil-in-water because the inside is red indicating that it contains Nile red dye, which is hydrophobic and soluble in the organic phase, and the outside is black indicating that it is the aqueous phase.

[0048] The inorganic salt medium used in the embodiment of the present invention has a final concentration composition of: KH2PO4 0.5 g / L, NaHPO4·12H2O 0.5 g / L, (NH4)2SO4 2 g / L, MgSO4·7H2O 0.1 g / L, K2HPO4 0.5 g / L, MnSO4·H2O 0.13 mg / L, CuSO4 0.03 mg / L, Na2MoO4·7H2O 0.2 mg / L, (NH4)6Mo7O 24 4H2O 0.347mg / L, the solvent is deionized water.

[0049] Example 1: Effect of different oil-water ratios on chlorobenzene degradation

[0050] The method for preparing the catalyst cell in the embodiment of the present invention comprises the following steps:

[0051] S1 solid culture: Pseudomonas putida CB-Y was inoculated into R2A solid culture medium and cultured at 30°C for 24 hours to obtain activated bacteria; the final concentration of the R2A solid culture medium was as follows: yeast powder 0.5 g / L, soluble starch 0.5 g / L, MgSO4 0.05 g / L, tryptone 0.5 g / L, glucose 0.5 g / L, sodium pyruvate 0.375 g / L, KH2PO4 0.45 g / L, agar 20 g / L, pH 7, and the solvent was deionized water;

[0052] S2 expansion culture: Use an inoculation loop to pick up the bacteria obtained in step S1, select a single colony and inoculate it into R2A liquid culture medium, and culture it at 30°C and 180 rpm for 12 hours. 600 = 1, enter the logarithmic growth phase, take 50 mL of the culture solution and centrifuge, wash twice with inorganic salt medium, add 12 ml of inorganic salt medium, disperse, and measure OD 600 =2, and the catalyst bacterial solution is obtained.

[0053] The steps for preparing the polymer emulsion are as follows: 20 mg of polymer 1 of blank example 1 is weighed and added to a 2 ml centrifuge tube, and then an inorganic salt medium is added. After the materials are dispersed, n-dodecane is added, and then ultrasonic (30 W, 30 Hz) treatment is performed for 5 seconds to prepare the polymer emulsion. According to this operation process, the polymer emulsions prepared under different conditions are marked as follows:

[0054] 1) The amount of inorganic salt culture medium used is 800 μl, the amount of n-dodecane used is 200 μl, and the corresponding product is marked as polymer emulsion 1.

[0055] 2) The amount of inorganic salt culture medium used is 600 μl, the amount of n-dodecane used is 400 μl, and the corresponding product is marked as polymer emulsion 2.

[0056] 3) The amount of inorganic salt culture medium used is 500 μl, the amount of n-dodecane used is 500 μl, and the corresponding product is marked as polymer emulsion 3.

[0057] 4) The amount of inorganic salt culture medium used is 400 μl, the amount of n-dodecane used is 600 μl, and the corresponding product is marked as polymer emulsion 4.

[0058] 5) The amount of inorganic salt culture medium used is 800 μl, the amount of n-dodecane used is 200 μl, and the corresponding product is marked as polymer emulsion 5.

[0059] 1 mL of the catalyst bacterial solution prepared above was centrifuged, the supernatant was removed and then mixed with 1 ml of polymer emulsion, chlorobenzene with a final concentration of 460 mg / L was added to form a catalytic degradation system, and the chlorobenzene was cultured at 30°C and 180 rpm with shaking to catalyze the degradation of chlorobenzene. When the polymer emulsions 1 to 5 were selected, the corresponding catalytic degradation systems were recorded as Emulsion 1, Emulsion 2, Emulsion 3, Emulsion 4 and Emulsion 5, respectively.

[0060] The degradation rate of chlorobenzene after 10 hours of degradation of chlorobenzene by emulsion-microorganism coupling system with different oil-water ratio (i.e. Emulsion 1-5) is as follows Figure 3 As shown in Figure 2, the chloride ion content in the aqueous phase after 10 hours of degradation of chlorobenzene is as follows: Figure 4 shown.

[0061] Example 2: Effect of different emulsion concentrations on chlorobenzene degradation

[0062] The steps for preparing the polymer emulsion are as follows: weigh polymer 1 and add it to a 2 ml centrifuge tube, then add 400 μl of inorganic salt culture medium, add 600 μl of n-dodecane after the materials are dispersed, and then ultrasonically treat (30 W, 30 Hz) for 5 seconds to prepare the polymer emulsion. According to this operation process, when the addition amount of polymer 1 is 10 mg, 30 mg, 40 mg and 50 mg, the corresponding products are marked as polymer emulsion 6, polymer emulsion 7, polymer emulsion 8 and polymer emulsion 9, respectively.

[0063] 1 mL of the catalyst bacterial solution prepared in Example 1 was centrifuged, the supernatant was removed and then mixed with 1 mL of the polymer emulsion, chlorobenzene with a final concentration of 460 mg / L was added to form a catalytic degradation system, and the chlorobenzene was cultured at 30° C. and 180 rpm with shaking to catalyze the degradation of chlorobenzene. When the polymer emulsions 6 to 9 were selected respectively, the corresponding catalytic degradation systems were recorded as Emulsion 6, Emulsion 7, Emulsion 8 and Emulsion 9, respectively.

[0064] The degradation rates of chlorobenzene after 10 h of degradation of chlorobenzene by emulsion-microorganism coupling systems with different emulsion concentrations (Emulsion 4, Emulsion 6-9) are as follows: Figure 5 As shown in Figure 2, the chloride ion content in the aqueous phase after 10 hours of degradation of chlorobenzene is as follows: Figure 6 shown.

[0065] Example 3: Degradation curve of chlorobenzene by emulsion-microorganism coupling system

[0066] 1) The catalytic degradation system Emulsion 4 of Example 1 was relabeled as Emulsion 10, and the degradation curve of chlorobenzene by the system over time and the chloride ion content in the aqueous phase after 13 hours of chlorobenzene degradation were recorded.

[0067] 2) Chlorobenzene with a final concentration of 460 mg / L was added to the polymer emulsion 4 of Example 1 to form a catalytic degradation system, and the chlorobenzene was catalytically degraded at 30° C. and 180 rpm. The catalytic degradation system was recorded as Emulsion 11. The time curve of the degradation of chlorobenzene by the system and the chloride ion content in the aqueous phase after 13 h of chlorobenzene degradation were recorded.

[0068] 3) 1 mL of the catalyst bacterial solution prepared in Example 1 was added to a 2 ml centrifuge tube, centrifuged first, and 20 mg of polymer 1 was added after removing the supernatant, and then 400 μl of inorganic salt culture medium, 600 μl of n-dodecane, and chlorobenzene with a final concentration of 460 mg / L were added to form a catalytic degradation system, and the catalytic degradation system was recorded as Emulsion 12 after static culture at 30°C. The degradation curve of chlorobenzene by the system over time and the chloride ion content in the aqueous phase after 13 h of chlorobenzene degradation were recorded.

[0069] 4) 1 mL of the catalyst bacterial solution prepared in Example 1 was centrifuged, and 1 ml of inorganic salt culture medium was added after removing the supernatant. Chlorobenzene with a final concentration of 460 mg / L was added to form a catalytic degradation system. The catalytic degradation system was recorded as Emulsion 13 at 30° C. and 180 rpm for catalytic degradation of chlorobenzene. The degradation curve of chlorobenzene by the system over time and the chloride ion content in the aqueous phase after 13 h of chlorobenzene degradation were recorded.

[0070] The change curve of chlorobenzene degradation over time by different catalytic degradation systems Emulsion 10-13 in Example 3 of the present invention can be found in Figure 7 As shown, the chloride ion content in the aqueous phase after 13 hours of degradation of chlorobenzene is shown in Figure 8 shown.

[0071] from Figure 7The chlorobenzene in the catalytic degradation system Emulsion 11 decreased slightly. The reason is that due to the amphiphilicity of the polymer, its hydrophobic segment can attract chlorobenzene through non-covalent bonding, reducing the free chlorobenzene content in the water. The subsequent chlorobenzene did not continue to decrease because there was no catalytic degradation of chlorobenzene. It can also be seen from the ion chromatography results that no chloride ions were detected in the water phase after 13 hours, indicating that chlorobenzene was not degraded.

[0072] from Figure 7 The chlorobenzene content of the medium catalytic degradation system Emulsion 12 decreased slightly. The reason is that since no emulsion was formed, the interface area between the two phases was smaller than that of Emulsion 10, so the chlorobenzene degradation effect was poor.

[0073] Example 4: Degradation curves of chlorobenzene by emulsion-microorganism coupling systems formed by different emulsifier materials

[0074] In this embodiment, the 4-pyridinemethylamine raw material in the above emulsifier material is replaced with 2-pyridinemethylamine and benzylamine, and the other raw materials and steps are the same.

[0075] The synthesis steps of polymer 2 were repeated as in blank example 1, with the only difference being that "4-pyridinemethylamine was replaced by 2-pyridinemethylamine of equal mass", and the other conditions remained unchanged.

[0076] The preparation steps of polymer 3 were repeated as in blank example 1, except that "4-pyridinemethylamine was replaced with an equal mass of benzylamine", and the other conditions remained unchanged.

[0077] 1) The preparation steps of polymer emulsion 14 are as follows: weigh 20 mg of polymer 2 and add it into a 2 ml centrifuge tube, then add 400 μl of inorganic salt culture medium, add 600 μl of n-dodecane after the material is dispersed, and then ultrasonically treat (30 W, 30 Hz) for 5 s to prepare polymer emulsion 14.

[0078] 1 mL of the catalyst bacterial solution prepared in Example 1 was centrifuged first, the supernatant was removed and then mixed with 1 mL of polymer emulsion 14, chlorobenzene with a final concentration of 460 mg / L was added to form a catalytic degradation system Emulsion 14, and the mixture was shaken and cultured at 30° C. and 180 rpm to catalyze the degradation of chlorobenzene.

[0079] The time-dependent degradation curves of chlorobenzene by the emulsion-microorganism coupling system Emulsion 14 formed by different emulsifier materials in Example 4 of the present invention and the catalytic degradation system Emulsion 13 in Example 3 are shown in FIG. Fig. 9 , the chloride ion content in the aqueous phase after 13h of degradation of chlorobenzene can be found in Fig.10 shown.

[0080] 2) The preparation steps of polymer emulsion 17 are as follows: weigh 20 mg of polymer 3 and add it into a 2 ml centrifuge tube, then add 400 μl of inorganic salt culture medium, add 600 μl of n-dodecane after the material is dispersed, and then ultrasonically treat (30 W, 30 Hz) for 5 s to prepare polymer emulsion 17.

[0081] 1 mL of the catalyst bacterial solution prepared in Example 1 was centrifuged first, the supernatant was removed and then mixed with 1 mL of polymer emulsion 17, and chlorobenzene with a final concentration of 460 mg / L was added to form a catalytic degradation system Emulsion 17, and cultured at 30° C. and 180 rpm with shaking to catalyze the degradation of chlorobenzene.

[0082] The time-dependent degradation curves of chlorobenzene by the emulsion-microorganism coupling system Emulsion 17 formed by different emulsifier materials in Example 4 of the present invention and the catalytic degradation system Emulsion 13 in Example 3 are shown in Fig.11 , the chloride ion content in the aqueous phase after 13h of degradation of chlorobenzene can be found in Fig.12 .

[0083] Example 5: Effects of different organic phases on the degradation of chlorobenzene

[0084] 1) Preparation steps of catalytic degradation system Emulsion 20 were repeated in the same manner as Emulsion 3 of Example 1, with the only difference being that "in the preparation process of the polymer emulsion, 500 μl of n-dodecane was replaced with an equal volume of n-decane", and the other conditions remained unchanged.

[0085] 2) The preparation steps of the catalytic degradation system Emulsion 21 were repeated in the same manner as in Emulsion 3 of Example 1, with the only difference being that “in the preparation process of the polymer emulsion, 500 μl of n-dodecane was replaced with an equal volume of n-tetradecane”, and the other conditions remained unchanged.

[0086] 3) The preparation steps of the catalytic degradation system Emulsion 22 were repeated in the same manner as Emulsion 3 of Example 1, with the only difference being that "in the preparation process of the polymer emulsion, 500 μl of n-dodecane was replaced with an equal volume of n-decanol", and the other conditions remained unchanged.

[0087] 4) Preparation steps of catalytic degradation system Emulsion 23 were repeated in the same manner as Emulsion 3 of Example 1, with the only difference being that “in the preparation of the polymer emulsion, 500 μl of n-dodecane was replaced with an equal volume of n-dodecyl alcohol”, and the other conditions remained unchanged.

[0088] The degradation rate of chlorobenzene after 10 h of degradation by different organic phase emulsion-microorganism coupling systems in Example 5 of the present invention is shown in Fig.13, the chloride ion content in the aqueous phase after 10 hours of degradation of chlorobenzene can be found in Fig.14 .

[0089] This application uses gas chromatography to detect the chlorobenzene content in water. The gas chromatograph model used in this experiment is ThermoScientific TRACE 1300, and the chromatographic column is SHIMADZU SH-Rxi-17 (30mm×0.32mm, 0.5μm). The injection port is 220℃. The column temperature is maintained at 45℃ for 1min, then increased to 100℃ at 100℃ / min, maintained for 2min, and finally increased to 180℃ at 100℃ / min, maintained for 1min. Detector: FID 250℃. Split flow rate is 20ml / min, split ratio is 10:1. Nitrogen is 35ml / min, air is 350ml / min, and hydrogen is 35ml / min. Injection volume is 0.8ml.

[0090] This application uses ion chromatography to detect the chloride ion content in water. The ion chromatograph model used in this experiment is ThermoScientific TM Dionex TM Aquion TM RFIC, chromatographic columns are Dionex IonPacAG 19 (4×50 mm), Dionex IonPacAS19 (4×250 mm). The suppressor current is 124 mA. The eluent is KOH, 20 mM for 5 min, then 50 mM for 5 min, and finally 20 mM for 5 min.

[0091] The contents described in this specification are merely an enumeration of implementation forms of the inventive concept, and the protection scope of the present invention should not be regarded as being limited to the specific forms described in the embodiments.

Claims

1. A polymer emulsion for biodegradation of chlorinated volatile organic compounds, characterized in that The polymer emulsion is an emulsion system obtained by ultrasonically mixing an amphiphilic block polymer in an immiscible C10-C14 carbon alkane solvent and an inorganic salt culture medium aqueous solution. The emulsion system is an oil-in-water system. The block polymer is polymer 1. A product formed by a nucleophilic addition reaction of 4-pyridinemethylamine and methacryloyl chloride is used as monomer 1. Monomer 1 is first polymerized on a chain transfer agent RAFT-CTA, and then polymerized with NIPAM and methacrylamide propyltrimethylammonium chloride under the action of an initiator to obtain polymer 1.

2. A polymer emulsion for biodegradation of chlorinated volatile organic compounds as claimed in claim 1, characterized in that The C10-C14 alkane solvent is selected from n-dodecane, and the volume ratio of the C10-C14 alkane solvent to the inorganic salt culture medium aqueous solution is 0.5-2:1, preferably 1.5:1; the concentration of the block polymer in the polymer emulsion is 10-50 mg / mL, preferably 20 mg / mL.

3. A polymer emulsion for biodegradation of chlorinated volatile organic compounds as claimed in claim 1, characterized in that The final concentration of the inorganic salt culture medium aqueous solution is as follows: KH2PO4 0.5 g / L, NaHPO4·12H2O 0.5 g / L, (NH4)2SO4 2 g / L, MgSO4·7H2O 0.1 g / L, K2HPO4 0.5 g / L, MnSO4·H2O 0.13 mg / L, CuSO4 0.03 mg / L, Na2MoO4·7H2O 0.2 mg / L, (NH4)6Mo7O 24 4H2O 0.347mg / L, the solvent is deionized water.

4. A polymer emulsion for biodegradation of chlorinated volatile organic compounds as claimed in claim 1, characterized in that According to parts by weight, the preparation method of the block polymer is: 1) 2.5±0.5 parts of monomer 1, 0.02±0.005 parts of AIBN and 0.17±0.03 parts of chain transfer agent RAFT-CTA were dissolved in DMF solvent, stirred under N2 atmosphere, and stirred in an oil bath at 70-80°C for 2-4 days to polymerize monomer 1 on the chain transfer agent RAFT-CTA; monomer 1 was prepared by nucleophilic addition reaction of 4-pyridinemethylamine and methacryloyl chloride; 2) Weigh 6.1±0.5 parts of NIPAM, 8±0.5 parts of methacrylamidopropyltrimethylammonium chloride (MAPTAC) and 0.1±0.05 parts of AIBN and dissolve them in DMF. Stir under N2 atmosphere and then transfer to the solution in step 1). Continue stirring in an oil bath at 70-80°C for 1-3 days. Finally, remove the solvent by suction to obtain polymer 1.

5. A polymer emulsion for biodegradation of chlorinated volatile organic compounds as claimed in claim 4, characterized in that In terms of weight parts, the preparation method of the monomer 1 comprises the following steps: 4-pyridinemethylamine, triethylamine and methacryloyl chloride are stirred in an ethyl acetate solvent under room temperature water bath conditions for 3-5 hours, and after the reaction is completed, saturated brine is used as an extractant for extraction and separation, the organic layer is dried over anhydrous sodium sulfate to remove moisture, and then the organic solvent is removed by filtration, and finally the mixture is separated by column chromatography to obtain monomer 1 after filtration.

6. A polymer emulsion for biodegradation of chlorinated volatile organic compounds as claimed in claim 5, characterized in that The volume ratio of the 4-pyridinemethylamine to triethylamine is 1:0.4-1.0, preferably 1:0.5-0.6; the volume ratio of the 4-pyridinemethylamine to methacryloyl chloride is 1:0.8-1.2, preferably 1:0.9-1.

0.

7. A catalytic system for biodegradation of chlorinated volatile organic compounds, characterized in that The catalytic system comprises the polymer emulsion according to claim 1 and a catalyst, and the bacterial body obtained by expanding the culture of Pseudomonas putida CB-Y is used as the catalyst, wherein Pseudomonas putida CB-Y is deposited in the China Center for Type Culture Collection, address: Wuhan University, China, 430072, deposit date: August 27, 2024, deposit number: CCTCC M 20241856, and classification name: Pseudomonasputida CB-Y.

8. A catalytic system for biodegradation of chlorinated volatile organic compounds as claimed in claim 7, characterized in that The concentration of the block polymer in the catalytic system is 10-50 mg / mL, preferably 20 mg / mL, and the OD of the catalyst bacteria is 600 Value = 0.5-4, preferably 1-2.

9. A catalytic system for biodegradation of chlorinated volatile organic compounds according to claim 7, characterized in that The method for preparing the catalyst cell comprises the following steps: S1 solid culture: Pseudomonas putida CB-Y was inoculated into R2A solid culture medium and cultured at room temperature for 20-30 hours to obtain activated bacteria; the final concentration of the R2A solid culture medium was as follows: yeast powder 0.5 g / L, soluble starch 0.5 g / L, MgSO4 0.05 g / L, tryptone 0.5 g / L, glucose 0.5 g / L, sodium pyruvate 0.375 g / L, KH2PO4 0.45 g / L, agar 20 g / L, pH 7, and the solvent was deionized water; S2 expansion culture: Use an inoculation loop to pick the bacteria obtained in step S1 and inoculate them into R2A liquid culture medium. Shake and culture at 100-200 rpm for 10-20 hours at room temperature. When entering the logarithmic growth phase, centrifuge, wash, and redisperse in an aqueous solution of an inorganic salt culture medium.

10. A method for biodegrading chlorinated volatile organic compounds, characterized in that Chlorinated volatile organic compounds are added to the catalytic system of claim 7 to form a catalytic degradation system, and the chlorinated volatile organic compounds are degraded by shaking at 100-200 rpm at room temperature.

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