An oil-resistant immobilized carrier and a synthesis method and application thereof

Abstract

The application relates to an oil-resistant immobilized carrier and a synthesis method and application thereof, which comprises the following steps: (1) placing aerogel in an acetic acid solution to react, and washing to neutral after taking out; (2) dissolving humic acid in a Fe(OH)3 solution, adding the aerogel, reacting at 50-70 DEG C, and washing to weak alkaline; obtaining modified aerogel; (3) loading active metal on the modified aerogel; (4) adsorbing sugar ester-producing microorganisms on the metal-loaded carrier, and drying to obtain the immobilized carrier. The immobilized carrier provided by the application has persistent oil resistance, can enhance the bonding force between the metal and the aerogel in the carrier, and improves the adsorbability and long-acting property of the carrier.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wastewater treatment, and particularly relates to an oil-resistant immobilized carrier and a synthesis method and application thereof. BACKGROUND

[0002] A large amount of oily sewage is produced in the process of oil exploitation, refining and processing, and the oil in the sewage exists in the form of floating oil, dispersed oil, emulsified oil and dissolved oil. The sewage is generally treated by a combined process due to the characteristics of large discharge amount, complex composition and large water quality fluctuation. The floating oil and dispersed oil can be removed by oil separation flotation, and the dissolved oil and part of the emulsified oil that is not easy to remove often enters the end biochemical unit with the wastewater. In order to meet the more stringent discharge standard, a three-stage biochemical treatment unit mainly using a biofilm reactor such as MBBR, BAF and FCBR is added. However, for oily sewage, the biofilm reactor cannot achieve ideal treatment effect after long-period operation.

[0003] Yang Qiu Yue (MBBR Process Treatment of Refinery Sewage Operation Analysis, China and Foreign Energy, 2020, 25(1)) increases the nutrients and high-quality carbon source at the inlet of the MBBR tank to promote the normal growth and reproduction of microorganisms, thereby improving the problem of biofilm formation. Sang Junqiang et al. (Study on the treatment of high-salinity refinery wastewater by fluidized composite carrier biofilm process, Petroleum Processing and Petrochemical Technology, 2017, 48(8)) use a new biofilm biochemical treatment process (FCBR) of a patented composite carrier, one carrier of which is attached to the microorganisms to reproduce and grow, forming a dense biofilm to improve the treatment efficiency, and the other carrier is uniformly dispersed in water to fix the pollutants, improving the impact resistance. The flow state of the carrier further strengthens the biological treatment capacity and improves the treatment efficiency.

[0004] At present, researchers mostly carry out a lot of work from the aspects of selection, ratio, modification of carrier materials and immobilization methods.

[0005] CN201610595544.6 discloses a method for treating ammonia-nitrogen wastewater by using porous cellulose aerogel immobilized microorganism bacteria, mainly preparing porous cellulose aerogel, and using carrier combination method to adsorb and immobilize nitrifying bacteria and denitrifying bacteria on the porous cellulose aerogel, so as to treat ammonia-nitrogen wastewater by immobilizing microorganism bacteria on the porous cellulose aerogel, which is beneficial to the simultaneous nitrification and denitrification reaction, has good ammonia-nitrogen removal capacity, high reaction efficiency and strong stability. The immobilized microorganism bacteria is added into 50-100 L of 100-500 mg / L ammonia-nitrogen wastewater at 20-30 g / L, the hydraulic retention time is 30-40 h, and the ammonia-nitrogen removal rate is 68-89% after treatment. However, the method uses cellulose aerogel to adsorb and immobilize bacteria, which belongs to surface adsorption. Since the binding force between the bacteria and the cellulose aerogel is not strong, the bacteria will fall off in long-term treatment. Especially when used for treating oil-containing wastewater, the adsorption capacity is poor due to the blockage of the pores by oil pollution, and the biological activity is poor, so the long-term stable operation effect cannot be achieved.

[0006] CN201210246151.6 discloses a coupling treatment method for oil-containing wastewater in an oil field. The oil-containing wastewater is subjected to two-stage biological contact oxidation treatment in a biochemical tank to obtain water to be filtered, and then the water to be filtered is filtered. In the biological contact oxidation treatment, aeration is adopted at the lower bottom of the biochemical tank, and a hydrophilic fiber filler with adsorbed bacillus is adopted above the aeration, oil-containing wastewater is introduced into the biochemical tank, and the volume ratio of the gas for aeration to the oil-containing wastewater, the pH value in the biochemical tank, the content ratio of C, N and P, and the dissolved oxygen content are controlled. The patent can completely remove the residual emulsified oil in the front-end wastewater system, improve the efficiency of the biochemical treatment system, and shorten the residence time of the wastewater in the biochemical system from more than 12 h to about 8 h. However, the invention uses the hydrophilic fiber filler with adsorbed bacillus to remove oil and fat, which requires matching of specific bacteria and materials, and the filler and the bacteria are combined only by adsorption, and the binding force needs to be further improved. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application provides an oil-resistant immobilized carrier and a synthesis method and application thereof. The immobilized carrier provided by the present application has persistent oil resistance, can enhance the binding force between the metal and the aerogel in the carrier, and improves the adsorption and long-acting properties of the carrier.

[0008] The first aspect of the present application provides a synthesis method of an oil-resistant immobilized carrier, comprising the following steps:

[0009] (1) reacting the aerogel in an acetic acid solution, and washing to neutral after taking out;

[0010] (2) humic acid is dissolved in Fe(OH)3 solution, aerogel is added, after reaction at 50-70 DEG C, washing to weak alkaline to obtain modified aerogel;

[0011] (3) active metal is loaded on the modified aerogel to obtain metal-loaded carrier;

[0012] (4) saccharide ester-producing microorganism is adsorbed on the metal-loaded carrier, after adsorption, drying is carried out to obtain immobilized carrier.

[0013] The aerogel in step (1) is at least one of carbon aerogel, silicon aerogel, cellulose aerogel and the like, preferably carbon aerogel. It is usually obtained by self-preparation or commercial purchase, and the specific surface area of the aerogel is 600-1100 m 2 / g, and the porosity is 80%-98%.

[0014] The concentration of the acetic acid solution in step (1) is 1.0-2.0 mol / L. The aerogel is immersed in the acetic acid solution for reaction, the reaction temperature is 30-50 DEG C, and the reaction time is 1.0-2.0 h. It can be directly heated or heated by water bath, and the water bath heating to 30-50 DEG C is preferred. After the aerogel is taken out, it is washed to neutral pH, generally 6.5-7.5.

[0015] The concentration of the Fe(OH)3 solution in step (2) is 0.5-0.8 mol / L, and the mass ratio of the Fe(OH)3 solution to humic acid is 1:1-3:1.

[0016] In step (2), the aerogel is immersed in the mixed system of humic acid and Fe(OH)3 solution, and is shaken and reacted in water bath at 50-70 DEG C for 3-5 h. After taking out, it is washed to weak alkaline pH, generally 7.6-8.0.

[0017] The active metal in step (3) is at least one of Cu 2+ , Fe 2+ , Mg 2+ and the like, preferably Fe 2+ . The active metal can be loaded by impregnation method commonly used in the art, for example, isometric volume, excessive impregnation and the like. Generally, soluble salt solution of the active metal is used, and the concentration of metal ions is 1-4 mol / L. For example, the modified aerogel can be immersed in the active metal solution, and is immersed at 60-70 DEG C for 6-10 h.

[0018] Further, in step (3), an auxiliary agent is added in the active metal solution, including (NH4)6Mo7O2·4H2O and CoCl2, and the molar ratio of the two is 1:3-5, and the amount is 0.5-1.0 mg / L. The addition of the auxiliary agent is helpful for the adsorption and growth of the saccharide ester-producing microorganism.

[0019] The step (4) of the present application is to immerse the metal-loaded carrier into the fermentation liquor of the sugar ester-producing microorganism for adsorption growth of the microorganism, and the volume ratio of the metal-loaded carrier to the fermentation liquor is 1:1-3. The adsorption growth conditions are as follows: temperature 20-38℃, preferably 20-30℃, pH 6.0-8.5, preferably 6.0-7.0, and reaction time 12-36h.

[0020] The sugar ester-producing microorganism in the step (4) of the present application is at least one of the microorganisms for producing at least one of rhamnose ester, trehalose lipid, sophorose lipid and sucrose ester by fermentation, such as at least one of Pseudomonas aeruginosa for producing rhamnose ester, Pseudomonas aeruginosa for producing trehalose lipid, etc. The preparation method of the fermentation liquor of the sugar ester-producing microorganism is conventional in the art.

[0021] The drying in the step (4) of the present application is carried out at 35-50℃ for 24-48h to obtain the immobilized carrier. The synthesized immobilized carrier needs to be stored in vacuum before use, and the storage time is generally 1-3 months.

[0022] The second aspect of the present application provides an oil-resistant immobilized carrier prepared by the method of the present application. In the prepared immobilized carrier, the metal content accounts for 1%-20% of the mass of the modified aerogel in terms of oxide, humic acid accounts for 0.1%-10% of the mass of the modified aerogel, and the sugar ester-producing microorganism accounts for 5%-50%, preferably 10%-30% of the mass of the modified aerogel.

[0023] The third aspect of the present application provides the application of the synthesized immobilized carrier in an oil-containing sewage treatment system. Specifically, the immobilized carrier is directly added into the oil-containing sewage treatment system or is loaded when the oil-containing sewage treatment system is newly started, and the active microorganisms in the oil-containing sewage treatment system are any one of decarburization bacteria, dephosphorization bacteria, denitrification bacteria, etc. These microorganisms generally do not have the ability to degrade oil, or the system generally does not contain microorganisms with the ability to degrade oil.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] (1) The present inventors found in research that, on the basis of aerogel pretreatment-humic acid modification-loading active metal, adding rhamnolipid can avoid the loss of active metal, but in the process of treating oily wastewater, the effect is unstable and shows a downward trend after long-term treatment. Analysis shows that the main reason is that part of the rhamnolipid is lost, which leads to a decrease in the binding force between the active metal and the carrier, and thus the treatment effect is unstable. To solve this problem, the present inventors load active metal on modified aerogel, and then adsorb microorganisms that produce rhamnolipid, thereby synthesizing a fixed carrier. The synthesized fixed carrier has persistent oil resistance in use, especially can avoid the loss of active metal, and does not affect the long-term stability of the wastewater treatment effect and system operation.

[0026] (2) The use of humic acid modified aerogel, and then loading active metal on the modified aerogel to synthesize an adsorption front carrier, is helpful to the adsorption of rhamnolipid-producing microorganisms, and through the synergistic effect between the three, the substances are tightly combined and have strong binding force, and will not be lost during long-term use.

[0027] (3) The synthesized fixed carrier has a pore structure suitable for the adsorption and reproduction of functional microorganisms in the treatment system, can ensure the adsorption amount of decarburization and denitrification microorganisms, and can avoid the loss of metal ions in the carrier during long-term treatment, thereby ensuring the treatment effect.

[0028] (4) The fixed carrier provided by the present application has good oil resistance, and can maintain the long-term effectiveness of the carrier application when used in the treatment of oily wastewater, and avoid the blockage and pollution of the carrier pore by oil substances. DETAILED DESCRIPTION

[0029] The method and effect of the present application will be further described in detail by the following examples. The examples are implemented on the premise of the technical scheme of the present application, and detailed implementation modes and specific operation processes are given, but the protection scope of the present application is not limited to the following examples.

[0030] In the following examples, the experimental methods are conventional methods in the art unless otherwise specified. The experimental materials used in the following examples are purchased from conventional biochemical reagent stores unless otherwise specified.

[0031] In the examples of the present application, the ammonia nitrogen concentration is determined by GB7478-87 "Determination of Ammonium in Water- Evaporation and Titration Method"; the metal ion is determined by inductively coupled plasma mass spectrometry; and the suspended solids in effluent are determined by GB11901-89 "Determination of Suspended Solids in Water-Gravimetric Method".

[0032] Example 1

[0033] (1) Carbon aerogel (specific surface area 800 m 2(1) Carbon aerogel (specific surface area 800 m2 / g, porosity 80%) was immersed in 1.5 mol / L acetic acid solution for water bath reaction, the reaction temperature was 40°C, and the shaking time was 1.5 h. After being taken out, the carbon aerogel was washed with deionized water until the pH was 7.0 to obtain the pretreated carbon aerogel.

[0034] (2) Humic acid was dissolved in 0.6 mol / L Fe(OH)3 solution according to the mass ratio of Fe(OH)3 solution to humic acid of 2:1, and then the pretreated carbon aerogel was added. The mixture was shaken in a water bath at 60°C for 4 h. After being taken out, the mixture was washed with deionized water until the pH was 8.0 to obtain the modified aerogel.

[0035] (3) A ferrous sulfate solution with a ferrous ion concentration of 1 mol / L was prepared, and the modified aerogel was added. The mixture was immersed under stirring at 65°C for 8 h to obtain the carrier loaded with active metals.

[0036] (4) The carrier loaded with active metals was mixed with the rhamnolipid-producing Pseudomonas aeruginosa fermentation broth, and the volume ratio of the carrier to the fermentation broth was 1:1. The mixture was adsorbed at a temperature of 30°C and a pH of 6.5 for 12 h to obtain the carrier adsorbed with Pseudomonas aeruginosa. The carrier adsorbed with the microorganism was taken out and dried at 45°C for 24 h to obtain the immobilized carrier.

[0037] The rhamnolipid-producing Pseudomonas aeruginosa used in this example was obtained according to the method provided in the literature "Screening of Biosurfactant-producing Bacteria" (Pan Bingfeng, Acta Microbiologica Sinica, June 1996, 39(3)). After enrichment culture and screening using blood plates, the strain with stable genetic traits and producing rhamnolipids was obtained by shake flask fermentation rescreening, and was identified as Pseudomonas aeruginosa by 16S rRNA and the like.

[0038] The preparation method of the Pseudomonas aeruginosa fermentation broth was as follows: colonies on the slant were inoculated into LB medium, and seed liquid was obtained by culturing at 37°C and 200 rpm for 24 h. Then, the seed liquid was inoculated into fermentation medium at 5%, the pH was 6.5, the culture was carried out at 35°C and 200 rpm for 7 days to obtain the fermentation broth. The formula of the fermentation medium was as follows (by mass fraction): glucose 5.0%, yeast extract 0.5%, KH2PO4, MgSO4, FeSO4·7H2O and CaCl2·2H2O were all 0.02%.

[0039] Example 2

[0040] (1) Carbon aerogel (specific surface area 800 m 2 / g, porosity 80%) was immersed in 1 mol / L acetic acid solution for water bath reaction, the reaction temperature was 30°C, and the shaking time was 1 h. After being taken out, the carbon aerogel was washed with deionized water until the pH was 6.5 to obtain the pretreated carbon aerogel.

[0041] (2) humic acid was added into 0.5 mol / L Fe(OH)3 solution according to the mass ratio of Fe(OH)3 solution to humic acid being 1:1, then the pretreated carbon aerogel was added, and the mixture was shaken in a water bath at 50℃ for 3h, and then removed and washed with deionized water until pH 7.6 was reached to obtain the modified aerogel.

[0042] (3) a ferrous sulfate solution with a concentration of 2 mol / L was prepared, and the modified aerogel was added into the solution, and then immersed in the solution under stirring at 60℃ for 6h to obtain a metal-loaded carrier.

[0043] (4) the metal-loaded carrier was mixed with a fermentation broth of a trehalose lipid-producing Pseudomonas aeruginosa, and the volume ratio of the carrier to the fermentation broth was 1:3. The mixture was adsorbed at 25℃ and pH 7.0 for 24h to obtain a carrier with adsorbed microorganisms. The carrier with adsorbed microorganisms was removed and dried at 35℃ for 48h to obtain a final immobilized carrier.

[0044] The Pseudomonas aeruginosa used in the example for producing trehalose ester was obtained according to the method provided in the literature "Screening of Bacterial Strains Producing Biosurfactants" (Pan Bingfeng, Acta Microbiologica Sinica, June 1996, 39(3)). After enrichment culture and screening using blood plates, a strain with stable genetic traits and producing trehalose ester was obtained by shake flask fermentation rescreening, and was identified as Pseudomonas aeruginosa by 16S rRNA and the like.

[0045] The preparation method of the fermentation broth of Pseudomonas aeruginosa was as follows: colonies on the slant were inoculated into LB medium, and seed liquid was obtained by culturing at 37℃ and 200 rpm for 24h, then the seed liquid was inoculated into fermentation medium at 5%, and the fermentation medium was cultured at 37℃ and 200 rpm for 7 days to obtain the fermentation broth. The formula of the fermentation medium was as follows (by mass fraction): glucose 2.0%, yeast extract 0.5%, peptone 1.0%, KH2PO4, MgSO4, FeSO4·7H2O and CaCl2·2H2O, each being 0.02%.

[0046] Example 3

[0047] (1) carbon aerogel (specific surface area 800 m 2 / g, porosity 80%) was immersed in 2.0 mol / L acetic acid solution for water bath reaction, the reaction temperature was 50℃, and the shaking time was 2h, then the product was removed and washed with deionized water until pH 7.4 was reached to obtain pretreated carbon aerogel.

[0048] (2) humic acid was added into 0.8 mol / L Fe(OH)3 solution according to the mass ratio of Fe(OH)3 solution to humic acid being 3:1, then the pretreated aerogel was added, and the mixture was shaken in a water bath at 70℃ for 5h, and then removed and washed with deionized water until pH 7.8 was reached to obtain modified aerogel.

[0049] (3) Prepare ferrous sulfate solution with iron ion concentration of 2 mol / L, and add the modified aerogel into the solution, and stir and immerse at 70℃ for 10 hours to obtain the metal-loaded carrier.

[0050] (4) The metal-loaded carrier and the rhamnose-producing Pseudomonas aeruginosa are mixed at a volume ratio of 1:2, and adsorption is carried out at 25℃ and pH 6.0 for 36 hours to obtain the carrier with adsorbed microorganisms, and the carrier with adsorbed microorganisms is taken out and dried at 40℃ for 36 hours to obtain the immobilized carrier.

[0051] Example 4

[0052] The same as in Example 1, except that the silica aerogel is used instead of the carbon aerogel, and the specific surface area of the silica aerogel is 1000 m 2 / g and the porosity is 85%. The immobilized carrier is finally obtained.

[0053] Example 5

[0054] The same as in Example 1, except that the cellulose aerogel is used instead of the carbon aerogel, and the specific surface area of the cellulose aerogel is 900 m 2 / g and the porosity is 95%. The immobilized carrier is finally obtained.

[0055] Example 6

[0056] The same as in Example 1, except that the metal ion is Cu 2+ , and 3 mol / L copper chloride solution is prepared instead of the iron sulfate solution. The immobilized carrier is finally obtained.

[0057] Example 7

[0058] The same as in Example 1, except that the metal ion is Mg 2+ , and 4 mol / L magnesium sulfate solution is prepared instead of the iron sulfate solution. The immobilized carrier is finally obtained.

[0059] Example 8

[0060] The same as in Example 1, except that (NH4)6Mo7O2·4H2O and CoCl2 are added in the active metal ion solution at 0.5 mg / L, and the molar ratio of (NH4)6Mo7O2·4H2O to CoCl2 is 1:4. The immobilized carrier is finally obtained.

[0061] Comparative Example 1

[0062] The same as in Example 1, except that the aerogel is not subjected to the pretreatment process in step (1), and is directly subjected to the humic acid modification in step (2). The immobilized carrier is finally obtained.

[0063] Comparative Example 2

[0064] The same as Example 1, except that in step (2), the humic acid was not used, only Fe(OH)3 solution was used. The immobilized carrier was finally prepared.

[0065] Comparative Example 3

[0066] The same as Example 1, except that in step (2), the humic acid was dissolved in water, i.e. Fe(OH)3 solution was not used. The immobilized carrier was finally prepared.

[0067] Comparative Example 4

[0068] The same as Example 1, except that in step (2), aerogel was added, and the reaction was carried out at 35°C. The immobilized carrier was finally prepared.

[0069] Comparative Example 5

[0070] The same as Example 1, except that in step (2), after the reaction, the washing was carried out to neutral, instead of weak alkaline. The immobilized carrier was finally prepared.

[0071] Comparative Example 6

[0072] The same as Example 1, except that in step (3), the modified aerogel was not loaded with metal ions. The immobilized carrier was finally prepared.

[0073] Comparative Example 7

[0074] The same as Example 1, except that in step (4), rhamnolipid was used instead of the fermentation broth of Pseudomonas aeruginosa producing rhamnolipid. The immobilized carrier was finally prepared.

[0075] Test Example

[0076] The immobilized carriers prepared in Examples 1-8 and Comparative Examples 1-7 were mixed with the suspension of nitrifying bacteria at a solid-liquid ratio of 1:5, and the immobilization reaction was carried out. When the ammonia nitrogen concentration reached 30 mg / L, and the effluent ammonia nitrogen concentration was less than 2 mg / L within 6 h, the immobilization of nitrifying bacteria was completed.

[0077] The above immobilized nitrifying bacteria were used for deep denitrification treatment of oil-containing wastewater. The ammonia nitrogen concentration in the wastewater was 30 mg / L, the petroleum was 10.0 mg / L, and no other metal ions were detected in the influent. After the test was continuously carried out for 3 months, the treatment effect was investigated, and the content of metal elements was detected. The specific results are shown in Table 1.

[0078] Table 1

[0079]

[0080] From Table 1, it can be seen that the oil-resistant immobilized carrier prepared according to the method of the present application has good ammonia-nitrogen removal effect after running for three months, the suspended solid concentration of the effluent is low, and almost no metal ions are detected in the effluent. The immobilized carriers prepared according to Comparative Examples 1-7 not according to the synthesis method of the present application have the phenomenon of metal ions falling off from the immobilized material, and the carriers are contaminated, which all result in poor ammonia-nitrogen treatment effect.

Claims

1. A method for synthesizing an oil-resistant immobilized carrier, characterized in that... Includes the following steps: (1) The aerogel is placed in an acetic acid solution for reaction, and then washed until the pH value is 6.5 to 7.5; the concentration of the acetic acid solution is 1.0 to 2.0 mol / L, the reaction temperature is 30 to 50℃, and the reaction time is 1.0 to 2.0 h; (2) Dissolve humic acid in Fe(OH)3 solution, add aerogel, and react in a water bath at 50-70℃ for 3-5 hours. Wash until the pH value is 7.6-8.0 to obtain modified aerogel. The concentration of Fe(OH)3 solution is 0.5-0.8 mol / L, and the mass ratio of Fe(OH)3 solution to humic acid is 1:1-3:

1. (3) Loading an active metal onto the modified aerogel to obtain a metal-loaded support; the active metal is Cu. 2+ Fe 2+ Mg 2+ At least one of them; (4) Adsorb the ester-producing microorganisms on the metal-loaded carrier, and obtain the immobilized carrier by drying after adsorption; the ester-producing microorganisms are at least one of Pseudomonas aeruginosa producing rhamnosyl esters and Pseudomonas aeruginosa producing phycolipids.

2. The method according to claim 1, characterized in that: The aerogel in step (1) is at least one of carbon aerogel, silica aerogel, and cellulose aerogel.

3. The method according to claim 2, characterized in that: The aerogel in step (1) is a carbon aerogel.

4. The method according to claim 1, 2, or 3, characterized in that: The specific surface area of ​​the aerogel in step (1) is 600–1100 m². 2 / g, porosity 80%~98%.

5. The method according to claim 1, characterized in that: Step (1) Heat directly or in a water bath to 30-50°C for reaction.

6. The method according to claim 5, characterized in that: Step (1) Heat in a water bath to 30-50°C for reaction.

7. The method according to claim 1, characterized in that: The active metal mentioned in step (3) is Fe. 2+ .

8. The method according to claim 1 or 7, characterized in that: Step (3) involves immersing the active metal in a soluble salt solution with a metal ion concentration of 1-4 mol / L at 60-70℃ for 6-10 hours.

9. The method according to claim 1 or 7, characterized in that: Step (3) Add an auxiliary agent to the solution of the active metal, including (NH4)6Mo7O2·4H2O and CoCl2, with a molar ratio of 1:3-5 and an amount of 0.5-1.0 mg / L.

10. The method according to claim 1, characterized in that: Step (4) involves immersing the metal-loaded carrier in the fermentation broth of the sugar-ester-producing microorganisms for cell adsorption and growth, with the volume ratio of the metal-loaded carrier to the fermentation broth being 1:1-3.

11. The method according to claim 1 or 10, characterized in that: The adsorption growth conditions for step (4) are: temperature 20-38℃, pH 6.0-8.5, and reaction time 12-36h.

12. The method according to claim 11, characterized in that: The temperature is 20-30℃, and the pH is 6.0-7.

0.

13. The method according to claim 1, characterized in that: The drying process described in step (4) involves drying at 35–50°C for 24–48 hours to obtain an immobilized carrier.

14. The method according to claim 1, characterized in that: The immobilized carrier synthesized in step (4) needs to be vacuum preserved before use for 1-3 months.

15. An oil-resistant immobilization carrier, characterized in that... It is synthesized by the method described in any one of claims 1-14.

16. The application of the immobilized carrier according to claim 15, characterized in that... The carrier was mixed with a nitrifying bacteria suspension for immobilization and then used in an oily wastewater treatment system.

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