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CN-121975785-A - Preparation method of oxidized tannic acid cross-linked enzyme-loaded membrane material and application of oxidized tannic acid cross-linked enzyme-loaded membrane material in membrane pollution prevention and control

CN121975785ACN 121975785 ACN121975785 ACN 121975785ACN-121975785-A

Abstract

The invention discloses a preparation method of an oxidized tannic acid cross-linked enzyme-loaded membrane material and application of the oxidized tannic acid cross-linked enzyme-loaded membrane material in membrane pollution prevention and control. The invention develops a method for immobilized quorum sensing quenching enzyme (AiiA enzyme) based on oxidized tannic acid modified cellulose acetate membrane. Compared with natural tannic acid, oxidized tannic acid has richer reactive sites on modification sites due to the introduction of quinone groups, can be combined with target substances more accurately and efficiently, and has the advantages of reaction selectivity and modification efficiency. The method uses oxidized tannic acid as a green cross-linking agent to replace toxic glutaraldehyde, fixes AiiA enzyme on the surface of the membrane through mild reaction, not only maintains high enzyme activity, but also generates synergistic effect with the quorum sensing quenching function of the enzyme by means of the antibacterial activity of tannic acid, so that the membrane flux attenuation rate in 24h simulated filtration is reduced by 40% -50%, and the technology has low cost and simple operation, is suitable for large-scale production, and provides a sustainable solution for MBR biological pollution resistance.

Inventors

  • SUN XIAOHUI
  • ZHANG LIANGLIANG
  • YAN YING
  • XU JINGXIN
  • YANG SUPING
  • ZHAO CHUNGUI

Assignees

  • 华侨大学
  • 厦门萤星海科技有限公司

Dates

Publication Date
20260505
Application Date
20260121

Claims (7)

  1. 1. The preparation method of the oxidized tannic acid cross-linked enzyme-carrying membrane material is characterized by comprising the following steps of: S1, preparing a cellulose acetate film by a phase inversion method: S1-1, slowly adding 5-25% of cellulose acetate into 45-70% of dimethylacetamide after preheating, sequentially adding 0.1-1.4% of Tween 80 and 1-10% of polyethylene alcohol, slowly dropwise adding 12-38.7% of deionized water, continuously stirring until the solution is in a completely transparent uniform state, and defoaming to prepare the casting solution; S1-2, mechanically scraping a film on a glass plate by using the film casting solution prepared in the step S1-1, immediately immersing the coated solution into water or a water-ethanol mixed solution with the concentration of 10% -30%, treating 5 min-30 min, taking out the film after the film is completely solidified, cleaning and solidifying to obtain a cellulose acetate film; S2, oxidizing the cellulose acetate film by oxidized tannic acid: S2-1, preparing oxidized tannic acid, namely dissolving tannic acid in 50 mL phosphate buffer solution, preparing an initial reaction mixture with tannic acid concentration of 0.5% -2%, regulating the pH value of the initial reaction mixture to 7.2, introducing laccase into the tannic acid solution, and initiating oxidative self-polymerization to obtain the oxidized tannic acid; S2-2, oxidizing the cellulose acetate film, namely soaking the cellulose acetate film prepared in the step S1-2 in PBS overnight, then washing with deionized water, drying, soaking the pretreated cellulose acetate film in an oxidized tannic acid solution prepared in the step S2-1, carrying out oscillation reaction at 20-40 ℃ and 20-80 r/min for 8 h-14 h, washing with the PBS solution, and storing in the PBS solution; s3, preparing the oxidized tannic acid cross-linked enzyme-carrying membrane material, namely immersing the cellulose acetate membrane treated in the step S2-2 into a quorum sensing quenching enzyme AiiA solution, and carrying out oscillation reaction at 4-37 ℃ and 20-80 r/min for 1 h-5 h to obtain the oxidized tannic acid cross-linked enzyme-carrying membrane material.
  2. 2. The method of claim 1, wherein the defoaming in step S1-1 is performed by one or more of vacuum standing, ultrasonic or centrifugation.
  3. 3. The method according to claim 1, wherein the conditions for the film scraping in step S1-2 are that the temperature is maintained at 25 ℃ and the relative humidity is 50% -70%.
  4. 4. The method according to claim 1, wherein the doctor blade thickness in step S1-2 is set to 0.1-0.5 mm, the doctor blade gap of the doctor blade apparatus is adjusted to 0.1-0.5 mm, and the mechanical doctor blade is performed at a steady speed of 10 cm/S.
  5. 5. The method of claim 1, wherein the laccase in step 2-1 is present in a concentration of 0.25-1 mg/mL.
  6. 6. The method according to claim 1, wherein the concentration of the quorum-quenching enzyme AiiA solution in step S3 is 0.83-3.33 g/m 3 .
  7. 7. Use of the oxidized tannic acid cross-linked enzyme-carrying membrane material prepared by the preparation method of any one of claims 1 to 6 in membrane pollution prevention and control.

Description

Preparation method of oxidized tannic acid cross-linked enzyme-loaded membrane material and application of oxidized tannic acid cross-linked enzyme-loaded membrane material in membrane pollution prevention and control Technical Field The invention relates to the technical field of sewage treatment biological membranes, in particular to a preparation method of an oxidized tannic acid cross-linked enzyme-loaded membrane material and application of the oxidized tannic acid cross-linked enzyme-loaded membrane material in membrane pollution prevention and control. Background The Membrane Bioreactor (MBR) is used as a high-efficiency sewage treatment technology, and is widely applied in the field of water treatment by virtue of the advantages of small occupied area, good treatment effect and the like. However, the membrane pollution problem, especially the biological pollution caused by the adhesion of microorganisms to form a biological membrane and the combined pollution of inorganic matters and organic matters formed by coupling, severely restrict the operation stability and the service life of MBR, increase the operation cost and become the main bottleneck for popularization and application of the technology. The quorum sensing quenching enzyme (such as AiiA enzyme) can degrade signal molecules in a bacterial quorum sensing system, inhibit the formation of a biological film, and provide a new thought for decoupling of membrane biological pollution and composite pollution, but the free quorum sensing quenching enzyme has the defects of easy inactivation and difficult recovery. The enzyme immobilization method commonly used at present mainly adopts Glutaraldehyde (GA) as a cross-linking agent, and realizes enzyme immobilization by activating a membrane surface group, but glutaraldehyde has certain toxicity, and the activity loss of the enzyme is easy to cause in the immobilization process, and meanwhile, the pollution resistance and the long-acting property of the glutaraldehyde are to be improved. Therefore, developing a novel enzyme-carrying membrane material which can solve the problems of toxicity and enzyme activity loss existing in the existing enzyme immobilization method and can improve the anti-pollution performance of the membrane becomes a technical problem to be solved urgently by the technicians in the field. Disclosure of Invention Aiming at the technical bottleneck of biological pollution of a membrane interface caused by bacterial biofilm formation in a membrane process, the invention provides an innovative solution, and develops a cellulose acetate membrane immobilized quorum sensing quenching enzyme (AiiA enzyme) method based on oxidized tannic acid modification. Compared with natural tannic acid, oxidized tannic acid has richer reactive sites on modification sites due to the introduction of quinone groups, can be combined with target substances more accurately and efficiently, and has the advantages of reaction selectivity and modification efficiency. The method uses oxidized tannic acid as a green cross-linking agent to replace toxic glutaraldehyde, fixes AiiA enzyme on the surface of the membrane through mild reaction, not only maintains high enzyme activity, but also generates synergistic effect with the quorum sensing quenching function of the enzyme by means of the antibacterial activity of tannic acid, so that the membrane flux attenuation rate in 24 h simulated filtration is reduced by 40% -50%, and the technology has low cost and simple operation, is suitable for large-scale production, and provides a sustainable solution for MBR biological pollution resistance. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: A preparation method of an oxidized tannic acid cross-linked enzyme-carrying membrane material comprises the following steps: S1, preparing a cellulose acetate film by a phase inversion method: S1-1, slowly adding 5-25% of cellulose acetate into 45-70% of dimethylacetamide after preheating, sequentially adding 0.1-1.4% of Tween 80 and 1-10% of polyethylene alcohol, slowly dropwise adding 12-38.7% of deionized water, continuously stirring until the solution is in a completely transparent uniform state, and defoaming to prepare the casting solution; S1-2, mechanically scraping a film on a glass plate by using the film casting solution prepared in the step S1-1, immediately immersing the coated solution into water or a water-ethanol mixed solution with the concentration of 10% -30%, treating 5 min-30 min, taking out the film after the film is completely solidified, cleaning and solidifying to obtain a cellulose acetate film; S2, oxidizing the cellulose acetate film by oxidized tannic acid: S2-1, preparing oxidized tannic acid, namely dissolving tannic acid in 50 mL phosphate buffer solution, preparing an initial reaction mixture with tannic acid concentration of 0.5% -2%, regulating the pH value of the initial reaction mixture to 7