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CN-116286781-B - Modified graphene oxide immobilized microorganism composite material and preparation method and application thereof

CN116286781BCN 116286781 BCN116286781 BCN 116286781BCN-116286781-B

Abstract

The invention discloses a modified graphene oxide immobilized microorganism composite material and a preparation method and application thereof, and belongs to the technical field of sewage treatment. According to the invention, graphene oxide is modified into a material with good biocompatibility through specific chemical modification treatment, and modified graphene oxide is adopted to fix functional microorganisms, so that the activity inhibition of the functional microorganisms is overcome, the biomass of denitrification and dephosphorization bacteria in a treatment reactor is greatly improved, and the efficient synchronous denitrification and dephosphorization treatment of garbage leachate is realized.

Inventors

  • JIANG BICUN
  • MA JUN
  • Tao Hujin
  • YANG JUN
  • WANG QIANG
  • LIU CHAO

Assignees

  • 南京环保产业创新中心有限公司

Dates

Publication Date
20260512
Application Date
20230424

Claims (10)

  1. 1. The preparation method of the modified graphene oxide immobilized microorganism composite material is characterized by comprising the following steps of: S10, graphene oxide pretreatment, namely adding graphene oxide, a dispersing agent, a biological compatibility improver and an enzyme cofactor into water, and carrying out ultrasonic treatment to obtain graphene oxide suspension, and then drying the graphene oxide suspension to obtain pretreated graphene oxide solid which is marked as GO1, wherein the dispersing agent is 1,3,6, 8-pyrene tetrasulfonic acid tetrasodium salt, the biological compatibility improver is a mixture of polylactic acid and polyethylene glycol, and the enzyme cofactor is magnesium ions; S20, modifying graphene oxide, namely dispersing the pretreated graphene oxide solid GO1 in an organic solvent, adding methacrylic acid, butyl methacrylate and azodiisobutyronitrile, performing polymerization grafting under the protection of nitrogen, and performing modification reaction on the graphene oxide solid GO1 to obtain a modified graphene oxide solid, namely GO2; S30, activating and culturing the modified graphene oxide immobilized microorganism to obtain bacterial liquid, uniformly mixing the bacterial liquid with the modified graphene oxide GO2, carrying out shaking culture and drying to obtain the modified graphene oxide immobilized microorganism composite material.
  2. 2. The preparation method of the modified graphene oxide immobilized microorganism composite material is characterized in that in the step S10, 1-1.2 g/L graphene oxide, 2-2.5 g/L1, 3,6, 8-pyrene tetrasulfonic acid tetrasodium salt, 0.5-0.7 g/L polylactic acid, 0.1-0.15 g/L polyethylene glycol and 0.1-0.2 g/L magnesium chloride are added into water, and ultrasonic treatment is carried out to obtain graphene oxide suspension.
  3. 3. The method of claim 1, wherein in the step S20, 200-250 mg of the pretreated graphene oxide solid GO1 is dispersed in 100-150 mL of N, N-dimethylformamide, 140-150 mu L of methacrylic acid, 770-790 mu L of butyl methacrylate and 15-18 mg of azobisisobutyronitrile are added for modification reaction, or In the step S20, the modification reaction is carried out under the protection of nitrogen for 10 hours under the condition of stirring at 70 ℃, after the reaction is finished, the mixture is cooled to room temperature, washed by acetone and dried at 60 ℃ to obtain the modified graphene oxide solid GO2.
  4. 4. The preparation method of the modified graphene oxide immobilized microorganism composite material according to claim 1, wherein in the step S30, the microorganism is a combination of the aureobasidium phosphate and the pseudomonas kunmingensis, and the volume ratio of the aureobasidium phosphate to the pseudomonas kunmingensis in the bacterial liquid is 1:3-1:3.5.
  5. 5. The preparation method of the modified graphene oxide immobilized microorganism composite material according to claim 1 is characterized in that in the step S30, the mass ratio of the modified graphene oxide GO2 to the bacterial liquid is 1:8-1:10.
  6. 6. The preparation method of the modified graphene oxide immobilized microorganism composite material is characterized in that in the step S30, the viable count of the phospho-ponifiable microzyme in the bacterial liquid is controlled to be 10 9 CFU/mL, the viable count of the pseudomonas kunming is controlled to be 10 10 CFU/mL, the bacterial liquid and the modified graphene oxide GO2 are uniformly mixed, and then subjected to shaking culture at 30 ℃ for 24-36 h, centrifuged at 4 ℃ and 5000rpm for 10min, and dried, so that the composite material is obtained.
  7. 7. The preparation method of the modified graphene oxide immobilized microorganism composite material according to any one of claims 1 to 6 is characterized in that in the step S30, the drying is freeze drying, the freeze drying method comprises the steps of pre-freezing at-45 ℃ to-50 ℃ for 2.7 to 3.0h, vacuumizing, starting to enter the next drying when the vacuum degree reaches below 0.15mbar, setting the vacuum degree to 0.28mbar, setting the temperature to 20 ℃ and the heating time to 3.0 to 3.5h, continuously heating to 30 ℃ after reaching, heating to 7.0 to 7.5h, slowly heating to 32 ℃ after reaching, heating to 13 to 15h, resolving and drying at 32 ℃ and drying for 20 to 22h, and obtaining the dried modified graphene oxide immobilized microorganism composite material.
  8. 8. A modified graphene oxide immobilized microorganism composite material is characterized by being prepared by adopting the preparation method of any one of claims 1-7, and the modified graphene oxide immobilized microorganism composite material comprises aureobasidium album and pseudomonas kunmingensis.
  9. 9. An application of the modified graphene oxide immobilized microorganism composite material in synchronous denitrification and dephosphorization of landfill leachate is characterized in that the modified graphene oxide immobilized microorganism composite material is inoculated into an SBR reactor according to the mass ratio of 20%, landfill leachate is filled for aeration activation, after activation is completed, the SBR reactor is controlled to perform circulation in aerobic and anoxic stages, aerobic and anoxic treatments are repeatedly performed, pH in the SBR reactor is controlled in the reaction process, and the content of ammonia nitrogen, total nitrogen and total phosphorus in the landfill leachate before and after the treatment is sampled and measured.
  10. 10. The application of the modified graphene oxide immobilized microorganism composite material in synchronous denitrification and dephosphorization of landfill leachate according to claim 9, wherein the maintenance time of an aerobic stage is 12h, the dissolved oxygen is controlled to be 3mg/L, the maintenance time of an anoxic stage is 6h, the dissolved oxygen is controlled to be 0.2mg/L, and the aerobic and anoxic treatments are repeatedly carried out for 5 days, or In the reaction process, controlling the pH value in the SBR reactor to be 7.5-8.2.

Description

Modified graphene oxide immobilized microorganism composite material and preparation method and application thereof Technical Field The invention belongs to the technical field of sewage treatment, and particularly relates to a modified graphene oxide immobilized microorganism composite material, and a preparation method and application thereof. Background The landfill leachate is high-concentration organic wastewater which is formed by deducting saturated water holding capacity of garbage and an overburden layer and passing through the garbage layer and the overburden layer from water contained in the garbage in a landfill, rain and snow water entering the landfill and other water. The landfill leachate has the characteristics of high organic pollutant content, high nitrogen and phosphorus content, complex components and the like, and if the landfill leachate is directly discharged into the environment without treatment, serious environmental pollution can be caused. The traditional activated sludge method has relatively low treatment efficiency on pollutants such as nitrogen and phosphorus in landfill leachate due to limited biomass of microorganisms in a reactor. The graphene oxide is a novel carbon material, has a high specific surface area, contains rich oxygen-containing functional groups such as hydroxyl, epoxy, carboxyl and carbonyl, is an ideal adsorption material, can be used as an adsorbent, and is applied to the field of wastewater treatment. For example, china patent application No. 201610476174.4, application No. 2016, 6 and 27 discloses an attapulgite and graphene oxide composite adsorbent and a preparation method thereof, wherein graphene oxide has a typical two-dimensional planar structure, has a large number of oxygen-containing functional groups such as hydroxyl groups, carboxyl groups and epoxy groups, hydrophilic molecules can be intercalated on the surface of graphene oxide through actions such as interlayer hydrogen bonds, ionic bonds and covalent bonds to form a composite, and the composite has the advantages of good hydrophilicity, strong adsorption capacity, low cost, easiness in separation from wastewater and high material recycling efficiency, and has practical application value in the field of water treatment. For another example, chinese patent application No. 201811277203.X, application day: 10 month 30 of 2018 discloses a microorganism composite preparation immobilized by graphene oxide nanocomposite, a preparation method and application thereof in coking wastewater. Firstly, preparing graphene oxide nano composite material, and secondly, preparing immobilized biological composite preparation. The graphene oxide nanocomposite is used for fixing the citric acid bacillus and the pseudomonas, so that the method can be better used for removing COD (chemical oxygen demand) of coking wastewater effluent. Nevertheless, graphene oxide also has a certain inhibition effect on the enzyme activity of certain microorganisms, such as urease and ammonia monooxygenase, so that the graphene oxide inhibits the activity of the microorganisms and reduces the biocompatibility. Disclosure of Invention 1. Problems to be solved Aiming at the problems that the existing graphene oxide immobilized microorganism treatment wastewater has poor treatment effect and the activity of the graphene oxide is inhibited, the invention provides a modified graphene oxide immobilized microorganism composite material and a preparation method and application thereof. The graphene oxide is subjected to specific chemical modification treatment, and the modified graphene oxide is adopted to fix the functional microorganisms, so that the active inhibition of the functional microorganisms is relieved, and the efficient synchronous denitrification and dephosphorization treatment of the landfill leachate is realized. 2. Technical proposal In order to solve the problems, the technical scheme adopted by the invention is as follows: the invention discloses a preparation method of a modified graphene oxide immobilized microorganism composite material, which comprises the following steps: S10, graphene oxide pretreatment, namely adding graphene oxide, a dispersing agent, a biocompatibility modifier and an enzyme cofactor into water, and performing ultrasonic treatment to obtain a graphene oxide suspension; S20, modifying graphene oxide, namely dispersing the pretreated graphene oxide solid GO1 in an organic solvent, adding methacrylic acid, butyl methacrylate and azodiisobutyronitrile, performing polymerization grafting under the protection of nitrogen, and performing modification reaction on the graphene oxide solid GO1 to obtain a modified graphene oxide solid, namely GO2; S30, activating and culturing the modified graphene oxide immobilized microorganism to obtain bacterial liquid, uniformly mixing the bacterial liquid with the modified graphene oxide GO2, carrying out shaking culture and drying to obtain the modified graphene