Salt-tolerant granular sludge and application thereof
By modifying the Fe3O4 nanoparticles of Aspergillus Tabin mycelia balls and combining flocculent activated sludge and powder activated charcoal, it cultivated in a high-salt environment, the problem of poor salt resistance in high-salt wastewater treatment was solved, and efficient pollution removal effect was achieved.
Patent Information
- Application Number
- CN202510142814.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-10
- Publication Date
- 2025-05-13
AI Technical Summary
The existing granular sludge has poor salt resistance and poor results when dealing with high salinity sewage.
Modified Fe3O4 nanoparticles were used to modify Aspergillus Tabin mycelium, combined with floc-shaped activated sludge and powder activated charcoal, and cultured in a high-salt environment to form salt-resistant granular sludge with a particle size of 2-3.5mm.
It significantly improves the bioactivity and salt resistance of the granular sludge, has excellent pollution removal ability, and is suitable for the treatment of high-salt wastewater.
Smart Images
Figure BDA0005265421020000091 
Figure BDA0005265421020000101
Abstract
Description
Technical Field
[0001] The invention relates to the field of granular sludge, and in particular to salt-resistant granular sludge and application thereof. Background Art
[0002] The formation of granular sludge is actually a form of microbial immobilization, and its appearance is relatively regular spherical or elliptical black particles. The particle size of granular sludge is generally 0.1-3mm, and some large ones are 5mm, with a density of 1.04-1.08g / cm 3 , slightly heavier than water, with good sedimentation performance and methanogenic activity for degrading organic matter in water. Observed under an optical microscope, granular sludge has a porous structure with a layer of transparent colloid on the surface, on which bacteria are attached. The cell density of the granular sludge close to the outer surface is relatively high, the internal structure is loose and the cell density is relatively low. Granular sludge with larger particle size often has a cavity, which is caused by the autolysis of cells due to insufficient nutrition inside the granular sludge. Large and empty granular sludge is easy to break, and its broken fragments become the core of new granular sludge. Some large granular sludge will also float easily because the gas generated inside is not easy to release. In addition, the existing granular sludge has poor salt tolerance and is less effective in treating high-salinity sewage. Therefore, it is necessary to further develop a salt-tolerant granular sludge. Summary of the invention
[0003] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a salt-tolerant granular sludge and its application.
[0004] The technical solution of the present invention is as follows:
[0005] A salt-tolerant granular sludge is prepared by modifying Aspergillus tubingensis hyphae with modified Fe3O4 nanoparticles to obtain modified Aspergillus tubingensis hyphae, and then inoculating flocculent activated sludge, powdered activated carbon and the modified Aspergillus tubingensis hyphae into a first synthetic wastewater, culturing for 3-5 days, separating and transferring the sludge into a second synthetic wastewater and culturing for 6-8 days to obtain granular sludge with a particle size of 2-3.5 mm.
[0006] As a preferred embodiment of the present invention, the preparation method of the modified Fe3O4 nanoparticles is as follows:
[0007] The sodium silicate solution is added dropwise to the Fe3O4 suspension, and the pH is adjusted to 5-6 to obtain Fe3O4 nanoparticles coated with silica. The Fe3O4 nanoparticles coated with silica are further dissolved in toluene, and aminopropyltriethylsilane is added to obtain secondary coated Fe3O4 nanoparticles. The secondary coated Fe3O4 nanoparticles are then added to a glutaraldehyde aqueous solution and immersed for 4-6 hours, and then dispersed in a quaternary ammonium chitosan aqueous solution to obtain modified Fe3O4 nanoparticles.
[0008] As a preferred embodiment of the present invention, the preparation method of the modified Aspergillus tubingensis mycelium pellet is as follows:
[0009] Aspergillus tubingensis spores were transferred to potato dextrose agar plates and cultured at 25-30°C for 6-8 days for strain activation. The spores were collected and added to sterile distilled water to prepare a concentration of 8-10×10 5 spore / ml spore suspension was inoculated into a culture medium containing modified Fe3O4 nanoparticles and cultured at 145-155 rpm and 25-30°C for 1-3 days to obtain modified Aspergillus tubingensis mycelium pellets.
[0010] As a preferred embodiment of the present invention, the salt concentration of the first synthetic wastewater is 2000-3500 mg / L, and the salt concentration of the second synthetic wastewater is 3500-4000 mg / L.
[0011] As a preferred embodiment of the present invention, the dry weight ratio of the flocculent activated sludge, powdered activated carbon and modified Aspergillus tubingensis mycelium pellets is 3-5:1-2:1.
[0012] As a preferred embodiment of the present invention, the culture conditions are: 20-35°C, 4-6 minutes of sedimentation, 4-6 minutes of decantation and drainage, 90-110 minutes of standing, 4-6 minutes of filling with water, and 350-400 minutes of aeration.
[0013] As a preferred embodiment of the present invention, the oxygen concentration during aeration is controlled to be 3-5 mg / L.
[0014] The present invention also discloses an application of the salt-tolerant granular sludge as described above in high-salt wastewater, wherein the sodium chloride content of the high-salt wastewater is 40-60 g / L.
[0015] The beneficial effects of the present invention are:
[0016] The present invention modifies the surface of Aspergillus tubingensis hyphae so that the surface has cations, which helps it to attract sludge microorganisms with negative charges on the cell surface, is more conducive to nucleation and agglomeration to form granular sludge, and further improves the biological activity of the granular sludge; the activity of β-galactosidase of Aspergillus tubingensis is significantly activated in a high-salt environment, and it can continuously accumulate salt and stimulate the secretion of a large amount of extracellular polysaccharides, thereby having significant salt resistance and excellent pollution removal properties. DETAILED DESCRIPTION
[0017] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. If no specific techniques or conditions are specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used that do not specify the manufacturer are all conventional products that can be obtained commercially.
[0018] The Aspergillus tubingensis used in the examples was purchased from the General Microbiology Center of China Culture Collection Administration (No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing); the collection number is CGMCC10022, and those skilled in the art can purchase it through public channels.
[0019] Example 1
[0020] A salt-tolerant granular sludge is prepared by modifying Aspergillus tubingensis hyphae with modified Fe3O4 nanoparticles to obtain modified Aspergillus tubingensis hyphae, and then inoculating flocculent activated sludge, powdered activated carbon and the modified Aspergillus tubingensis hyphae into a first synthetic wastewater, culturing for 3 days, separating and transferring the sludge into a second synthetic wastewater and culturing for 6 days to obtain granular sludge with a particle size of 2-3.5 mm.
[0021] The preparation method of the modified Fe3O4 nanoparticles is as follows:
[0022] Sodium silicate solution is added dropwise to the Fe3O4 suspension and the pH is adjusted to 6 to obtain silica-coated Fe3O4 nanoparticles. The silica-coated Fe3O4 nanoparticles are further dissolved in toluene and aminopropyltriethylsilane is added to obtain secondary-coated Fe3O4 nanoparticles. The secondary-coated Fe3O4 nanoparticles are then added to a glutaraldehyde aqueous solution and immersed for 4 hours, and then dispersed in a quaternary ammonium chitosan aqueous solution to obtain modified Fe3O4 nanoparticles.
[0023] The preparation method of the modified Aspergillus tubingensis mycelium pellet is as follows:
[0024] Aspergillus tubingensis spores were transferred to potato dextrose agar plates and cultured at 28 °C for 7 days for strain activation. Spores were collected and added to sterile distilled water to prepare a concentration of 9 × 10 5 spore / ml spore suspension was inoculated into a culture medium containing modified Fe3O4 nanoparticles and cultured at 150 rpm and 28°C for 2 days to obtain modified Aspergillus tubingensis mycelial pellets.
[0025] The salt concentration of the first synthetic wastewater is 2000 mg / L, and the salt concentration of the second synthetic wastewater is 3500 mg / L.
[0026] The dry weight ratio of the flocculent activated sludge, powdered activated carbon and modified Aspergillus tubingensis mycelium pellets is 3:1:1.
[0027] The culture conditions are: 30°C, 5 minutes of sedimentation, 5 minutes of decantation drainage (50vt% exchange rate), 100 minutes of standing, 5 minutes of filling with water, and 350 minutes of aeration.
[0028] The oxygen concentration during aeration is controlled to be 4 mg / L.
[0029] Example 2
[0030] A salt-tolerant granular sludge is prepared by modifying Aspergillus tubingensis hyphae with modified Fe3O4 nanoparticles to obtain modified Aspergillus tubingensis hyphae, and then inoculating flocculent activated sludge, powdered activated carbon and the modified Aspergillus tubingensis hyphae into a first synthetic wastewater, culturing for 4 days, separating and transferring the sludge into a second synthetic wastewater and culturing for 7 days to obtain granular sludge with a particle size of 2-3.5 mm.
[0031] The preparation method of the modified Fe3O4 nanoparticles is as follows:
[0032] Sodium silicate solution is added dropwise to the Fe3O4 suspension and the pH is adjusted to 6 to obtain silica-coated Fe3O4 nanoparticles. The silica-coated Fe3O4 nanoparticles are further dissolved in toluene and aminopropyltriethylsilane is added to obtain secondary-coated Fe3O4 nanoparticles. The secondary-coated Fe3O4 nanoparticles are then added to a glutaraldehyde aqueous solution and immersed for 5 hours, and then dispersed in a quaternary ammonium chitosan aqueous solution to obtain modified Fe3O4 nanoparticles.
[0033] The preparation method of the modified Aspergillus tubingensis mycelium pellet is as follows:
[0034] Aspergillus tubingensis spores were transferred to potato dextrose agar plates and cultured at 28 °C for 6-8 days for strain activation. Spores were collected and added to sterile distilled water to prepare a concentration of 9 × 10 5 spore / ml spore suspension was inoculated into a culture medium containing modified Fe3O4 nanoparticles and cultured at 140 rpm and 28°C for 2 days to obtain modified Aspergillus tubingensis mycelial pellets.
[0035] The salt concentration of the first synthetic wastewater is 3000 mg / L, and the salt concentration of the second synthetic wastewater is 4000 mg / L.
[0036] The dry weight ratio of the flocculent activated sludge, powdered activated carbon and modified Aspergillus tubingensis mycelium pellets is 3:1:1.
[0037] The culture conditions are: 30°C, 5 minutes of sedimentation, 5 minutes of decantation drainage, 100 minutes of standing, 5 minutes of filling with water, and 350 minutes of aeration.
[0038] The oxygen concentration during aeration is controlled to be 4 mg / L.
[0039] Example 3
[0040] A salt-tolerant granular sludge is prepared by modifying Aspergillus tubingensis hyphae with modified Fe3O4 nanoparticles to obtain modified Aspergillus tubingensis hyphae, and then inoculating flocculent activated sludge, powdered activated carbon and the modified Aspergillus tubingensis hyphae into a first synthetic wastewater, culturing for 4 days, separating and transferring the sludge into a second synthetic wastewater and culturing for 7 days to obtain granular sludge with a particle size of 2-3.5 mm.
[0041] The preparation method of the modified Fe3O4 nanoparticles is as follows:
[0042] Sodium silicate solution is added dropwise to the Fe3O4 suspension and the pH is adjusted to 5 to obtain silica-coated Fe3O4 nanoparticles. The silica-coated Fe3O4 nanoparticles are further dissolved in toluene and aminopropyltriethylsilane is added to obtain secondary-coated Fe3O4 nanoparticles. The secondary-coated Fe3O4 nanoparticles are then added to a glutaraldehyde aqueous solution and immersed for 4 hours, and then dispersed in a quaternary ammonium chitosan aqueous solution to obtain modified Fe3O4 nanoparticles.
[0043] The preparation method of the modified Aspergillus tubingensis mycelium pellet is as follows:
[0044] Aspergillus tubingensis spores were transferred to potato dextrose agar plates and cultured at 30 °C for 6 days for strain activation. Spores were collected and added to sterile distilled water to prepare a concentration of 9 × 10 5 spore / ml spore suspension was inoculated into a culture medium containing modified Fe3O4 nanoparticles and cultured at 145-155 rpm and 30°C for 1 day to obtain modified Aspergillus tubingensis mycelial pellets.
[0045] The salt concentration of the first synthetic wastewater is 3500 mg / L, and the salt concentration of the second synthetic wastewater is 4000 mg / L.
[0046] The dry weight ratio of the flocculent activated sludge, powdered activated carbon and modified Aspergillus tubingensis mycelium pellets is 3:1:1.
[0047] The culture conditions are: 30°C, 5 minutes of sedimentation, 5 minutes of decantation and drainage, 100 minutes of standing, 5 minutes of filling with water, and 400 minutes of aeration.
[0048] The oxygen concentration during aeration is controlled to be 4 mg / L.
[0049] Example 4
[0050] A salt-tolerant granular sludge is prepared by modifying Aspergillus tubingensis hyphae with modified Fe3O4 nanoparticles to obtain modified Aspergillus tubingensis hyphae, and then inoculating flocculent activated sludge, powdered activated carbon and the modified Aspergillus tubingensis hyphae into a first synthetic wastewater, culturing for 5 days, separating and transferring the sludge into a second synthetic wastewater and culturing for 7 days to obtain granular sludge with a particle size of 2-3.5 mm.
[0051] The preparation method of the modified Fe3O4 nanoparticles is as follows:
[0052] The sodium silicate solution is added dropwise to the Fe3O4 suspension, and the pH is adjusted to 5-6 to obtain silica-coated Fe3O4 nanoparticles. The silica-coated Fe3O4 nanoparticles are further dissolved in toluene, and aminopropyltriethylsilane is added to obtain secondary-coated Fe3O4 nanoparticles. The secondary-coated Fe3O4 nanoparticles are then added to a glutaraldehyde aqueous solution and immersed for 5 hours, and then dispersed in a quaternary ammonium chitosan aqueous solution to obtain modified Fe3O4 nanoparticles.
[0053] The preparation method of the modified Aspergillus tubingensis mycelium pellet is as follows:
[0054] Aspergillus tubingensis spores were transferred to potato dextrose agar plates and cultured at 28 °C for 8 days for strain activation. Spores were collected and added to sterile distilled water to prepare a concentration of 10 × 10 5 spore / ml spore suspension was inoculated into a culture medium containing modified Fe3O4 nanoparticles and cultured at 155 rpm and 28°C for 2 days to obtain modified Aspergillus tubingensis mycelial pellets.
[0055] The salt concentration of the first synthetic wastewater is 2800 mg / L, and the salt concentration of the second synthetic wastewater is 3800 mg / L.
[0056] The dry weight ratio of the flocculent activated sludge, the powdered activated carbon and the modified Aspergillus tubingensis mycelium pellet is 4:1:1.
[0057] The culture conditions are: 30°C, 5 minutes of sedimentation, 5 minutes of decantation and drainage, 100 minutes of standing, 5 minutes of filling with water, and 400 minutes of aeration.
[0058] The oxygen concentration during aeration is controlled to be 4 mg / L.
[0059] Example 5
[0060] A salt-tolerant granular sludge is prepared by modifying Aspergillus tubingensis hyphae with modified Fe3O4 nanoparticles to obtain modified Aspergillus tubingensis hyphae, and then inoculating flocculent activated sludge, powdered activated carbon and the modified Aspergillus tubingensis hyphae into a first synthetic wastewater, culturing for 4 days, separating and transferring the sludge into a second synthetic wastewater and culturing for 8 days to obtain granular sludge with a particle size of 2-3.5 mm.
[0061] The preparation method of the modified Fe3O4 nanoparticles is as follows:
[0062] The sodium silicate solution is added dropwise to the Fe3O4 suspension, and the pH is adjusted to 5-6 to obtain silica-coated Fe3O4 nanoparticles. The silica-coated Fe3O4 nanoparticles are further dissolved in toluene, and aminopropyltriethylsilane is added to obtain secondary-coated Fe3O4 nanoparticles. The secondary-coated Fe3O4 nanoparticles are then added to a glutaraldehyde aqueous solution and immersed for 5 hours, and then dispersed in a quaternary ammonium chitosan aqueous solution to obtain modified Fe3O4 nanoparticles.
[0063] The preparation method of the modified Aspergillus tubingensis mycelium pellet is as follows:
[0064] Aspergillus tubingensis spores were transferred to potato dextrose agar plates and cultured at 28 °C for 7 days for strain activation. Spores were collected and added to sterile distilled water to prepare a concentration of 9 × 10 5 spore / ml spore suspension was inoculated into a culture medium containing modified Fe3O4 nanoparticles and cultured at 145-155rpm and 28°C for 2 days to obtain modified Aspergillus tubingensis mycelial pellets.
[0065] The salt concentration of the first synthetic wastewater is 2500 mg / L, and the salt concentration of the second synthetic wastewater is 4000 mg / L.
[0066] The dry weight ratio of the flocculent activated sludge, powdered activated carbon and modified Aspergillus tubingensis mycelium pellets is 5:2:1.
[0067] The culture conditions are: 30°C, 5 minutes of sedimentation, 5 minutes of decantation and drainage, 100 minutes of standing, 5 minutes of filling with water, and 400 minutes of aeration.
[0068] The oxygen concentration during aeration is controlled to be 5 mg / L.
[0069] Comparative Example 1 (flocculent sludge)
[0070] This comparative example uses flocculent sludge for comparison.
[0071] Comparative Example 2 (Fe3O4 nanoparticles are not modified)
[0072] In this comparative example, Fe3O4 nanoparticles are directly used to modify the Aspergillus tubingensis mycelium pellets.
[0073] Comparative Example 3 (Aspergillus tubingensis mycelium pellets are not modified)
[0074] In this comparative example, Aspergillus tubingensis mycelium pellets were directly used without modification.
[0075] The wastewater of the above examples and comparative examples was tested for COD and total nitrogen removal capabilities in a high-salt environment (50 g / L sodium chloride).
[0076] Table 1 Performance test results of embodiments and comparative examples
[0077]
[0078]
[0079] It can be seen from the above table that the performance of the embodiment is better than that of the comparative example, the main reason for which may be that, in the embodiment, the surface of the Aspergillus tubingensis mycelium pellet is surface modified so that the surface has cations, which helps it to attract negatively charged sludge microorganisms on the cell surface, is more conducive to flocculation sludge nucleation and agglomeration to form granular sludge, and further improves the biological activity of the granular sludge; in addition, the modified Aspergillus tubingensis mycelium pellet is more conducive to the significant activation of the activity of β-galactosidase of Aspergillus tubingensis in a high-salt environment, can continuously accumulate salt, and stimulate the secretion of a large amount of extracellular polysaccharides, thereby having significant salt resistance and excellent dirt removal properties.
[0080] The above-mentioned embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all these changes and deformations should fall within the scope of protection of the claims of the present invention.
Claims
1. A salt-tolerant granular sludge, characterized in that: Modified Fe3O4 nanoparticles are used to modify the Aspergillus tubingensis mycelium pellets to obtain modified Aspergillus tubingensis mycelium pellets, and then flocculent activated sludge, powdered activated carbon and the modified Aspergillus tubingensis mycelium pellets are inoculated into the first synthetic wastewater, cultured for 3-5 days, separated and transferred to the second synthetic wastewater for culture for 6-8 days, and granular sludge with a particle size of 2-3.5 mm is obtained.
2. The salt-tolerant granular sludge according to claim 1, characterized in that: The preparation method of the modified Fe3O4 nanoparticles is as follows: The sodium silicate solution is added dropwise to the Fe3O4 suspension, and the pH is adjusted to 5-6 to obtain Fe3O4 nanoparticles coated with silica. The Fe3O4 nanoparticles coated with silica are further dissolved in toluene, and aminopropyltriethylsilane is added to obtain secondary coated Fe3O4 nanoparticles. The secondary coated Fe3O4 nanoparticles are then added to a glutaraldehyde aqueous solution and immersed for 4-6 hours, and then dispersed in a quaternary ammonium chitosan aqueous solution to obtain modified Fe3O4 nanoparticles.
3. The salt-tolerant granular sludge according to claim 1, characterized in that: The preparation method of the modified Aspergillus tubingensis mycelium pellet is as follows: Aspergillus tubingensis spores were transferred to potato dextrose agar plates and cultured at 25-30°C for 6-8 days for strain activation. The spores were collected and added to sterile distilled water to prepare a concentration of 8-10×10 5 spore / ml spore suspension was inoculated into a culture medium containing modified Fe3O4 nanoparticles and cultured at 145-155 rpm and 25-30°C for 1-3 days to obtain modified Aspergillus tubingensis mycelium pellets.
4. The salt-tolerant granular sludge according to claim 1, characterized in that: The salt concentration of the first synthetic wastewater is 2000-3500 mg / L, and the salt concentration of the second synthetic wastewater is 3500-4000 mg / L.
5. The salt-tolerant granular sludge according to claim 1, characterized in that: The dry weight ratio of the flocculent activated sludge, powdered activated carbon and modified Aspergillus tubingensis mycelium pellets is 3-5:1-2:
1.
6. The salt-tolerant granular sludge according to claim 1, characterized in that: The culture conditions are: 20-35° C., 4-6 minutes of sedimentation, 4-6 minutes of decantation drainage, 90-110 minutes of standing, 4-6 minutes of filling with water, and 350-400 minutes of aeration.
7. The salt-tolerant granular sludge according to claim 6, characterized in that: The oxygen concentration during aeration is controlled to be 3-5 mg / L.
8. Use of the salt-tolerant granular sludge according to any one of claims 1 to 7 in high-salinity wastewater, characterized in that: The sodium chloride content of the high-salt wastewater is 40-60 g / L.