CN117023811A - Degradable slow-release microsphere for water treatment and preparation method thereof - Google Patents
Degradable slow-release microsphere for water treatment and preparation method thereof Download PDFInfo
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- CN117023811A CN117023811A CN202310937866.4A CN202310937866A CN117023811A CN 117023811 A CN117023811 A CN 117023811A CN 202310937866 A CN202310937866 A CN 202310937866A CN 117023811 A CN117023811 A CN 117023811A
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 65
- 239000004005 microsphere Substances 0.000 title claims abstract description 50
- 238000002360 preparation method Methods 0.000 title claims abstract description 17
- 239000004642 Polyimide Substances 0.000 claims abstract description 26
- 229920001721 polyimide Polymers 0.000 claims abstract description 26
- 238000002156 mixing Methods 0.000 claims abstract description 19
- 238000001035 drying Methods 0.000 claims abstract description 17
- 238000011068 loading method Methods 0.000 claims abstract description 10
- 239000011248 coating agent Substances 0.000 claims abstract description 9
- 238000000576 coating method Methods 0.000 claims abstract description 9
- 238000002791 soaking Methods 0.000 claims abstract description 6
- 239000000178 monomer Substances 0.000 claims description 80
- WFDIJRYMOXRFFG-UHFFFAOYSA-N Acetic anhydride Chemical compound CC(=O)OC(C)=O WFDIJRYMOXRFFG-UHFFFAOYSA-N 0.000 claims description 51
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims description 42
- 241000894006 Bacteria Species 0.000 claims description 28
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 claims description 26
- GTDPSWPPOUPBNX-UHFFFAOYSA-N ac1mqpva Chemical compound CC12C(=O)OC(=O)C1(C)C1(C)C2(C)C(=O)OC1=O GTDPSWPPOUPBNX-UHFFFAOYSA-N 0.000 claims description 26
- 239000002202 Polyethylene glycol Substances 0.000 claims description 24
- 150000004985 diamines Chemical class 0.000 claims description 24
- 229920001223 polyethylene glycol Polymers 0.000 claims description 24
- 229920000159 gelatin Polymers 0.000 claims description 22
- 108010010803 Gelatin Proteins 0.000 claims description 19
- 239000008273 gelatin Substances 0.000 claims description 19
- 235000019322 gelatine Nutrition 0.000 claims description 19
- 235000011852 gelatine desserts Nutrition 0.000 claims description 19
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 18
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 18
- 239000000203 mixture Substances 0.000 claims description 17
- 238000010438 heat treatment Methods 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 15
- 230000001546 nitrifying effect Effects 0.000 claims description 14
- 239000003054 catalyst Substances 0.000 claims description 13
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 claims description 13
- UENRXLSRMCSUSN-UHFFFAOYSA-N 3,5-diaminobenzoic acid Chemical group NC1=CC(N)=CC(C(O)=O)=C1 UENRXLSRMCSUSN-UHFFFAOYSA-N 0.000 claims description 12
- 229920000642 polymer Polymers 0.000 claims description 12
- 239000000126 substance Substances 0.000 claims description 12
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 claims description 11
- IXPNQXFRVYWDDI-UHFFFAOYSA-N 1-methyl-2,4-dioxo-1,3-diazinane-5-carboximidamide Chemical compound CN1CC(C(N)=N)C(=O)NC1=O IXPNQXFRVYWDDI-UHFFFAOYSA-N 0.000 claims description 10
- 239000002244 precipitate Substances 0.000 claims description 10
- 235000010413 sodium alginate Nutrition 0.000 claims description 10
- 229940005550 sodium alginate Drugs 0.000 claims description 10
- 239000000661 sodium alginate Substances 0.000 claims description 10
- 239000002736 nonionic surfactant Substances 0.000 claims description 9
- 238000003756 stirring Methods 0.000 claims description 9
- 244000063299 Bacillus subtilis Species 0.000 claims description 7
- 235000014469 Bacillus subtilis Nutrition 0.000 claims description 7
- 125000006160 pyromellitic dianhydride group Chemical group 0.000 claims description 6
- HLBLWEWZXPIGSM-UHFFFAOYSA-N 4-Aminophenyl ether Chemical compound C1=CC(N)=CC=C1OC1=CC=C(N)C=C1 HLBLWEWZXPIGSM-UHFFFAOYSA-N 0.000 claims description 5
- 239000012298 atmosphere Substances 0.000 claims description 5
- 239000012043 crude product Substances 0.000 claims description 5
- 239000000839 emulsion Substances 0.000 claims description 5
- 229940057995 liquid paraffin Drugs 0.000 claims description 5
- 230000001681 protective effect Effects 0.000 claims description 5
- 238000005406 washing Methods 0.000 claims description 5
- 241000193830 Bacillus <bacterium> Species 0.000 claims description 2
- 230000003009 desulfurizing effect Effects 0.000 claims description 2
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 abstract description 21
- 230000000694 effects Effects 0.000 abstract description 21
- 238000000746 purification Methods 0.000 abstract description 11
- 230000007774 longterm Effects 0.000 abstract description 3
- 239000010865 sewage Substances 0.000 abstract description 3
- 239000002351 wastewater Substances 0.000 description 13
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 9
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Natural products CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 8
- PRXRUNOAOLTIEF-ADSICKODSA-N Sorbitan trioleate Chemical compound CCCCCCCC\C=C/CCCCCCCC(=O)OC[C@@H](OC(=O)CCCCCCC\C=C/CCCCCCCC)[C@H]1OC[C@H](O)[C@H]1OC(=O)CCCCCCC\C=C/CCCCCCCC PRXRUNOAOLTIEF-ADSICKODSA-N 0.000 description 7
- 230000000813 microbial effect Effects 0.000 description 7
- 235000010482 polyoxyethylene sorbitan monooleate Nutrition 0.000 description 7
- 229920000053 polysorbate 80 Polymers 0.000 description 7
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 6
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 6
- 230000001580 bacterial effect Effects 0.000 description 5
- 238000006116 polymerization reaction Methods 0.000 description 5
- XVMSFILGAMDHEY-UHFFFAOYSA-N 6-(4-aminophenyl)sulfonylpyridin-3-amine Chemical compound C1=CC(N)=CC=C1S(=O)(=O)C1=CC=C(N)C=N1 XVMSFILGAMDHEY-UHFFFAOYSA-N 0.000 description 4
- 241000589755 Pseudomonas mendocina Species 0.000 description 4
- 238000006136 alcoholysis reaction Methods 0.000 description 4
- 230000015556 catabolic process Effects 0.000 description 4
- 238000006731 degradation reaction Methods 0.000 description 4
- 239000009519 fu-yuan Substances 0.000 description 4
- JOXIMZWYDAKGHI-UHFFFAOYSA-N p-toluenesulfonic acid Substances CC1=CC=C(S(O)(=O)=O)C=C1 JOXIMZWYDAKGHI-UHFFFAOYSA-N 0.000 description 4
- 125000005489 p-toluenesulfonic acid group Chemical group 0.000 description 4
- 239000011148 porous material Substances 0.000 description 4
- 125000003944 tolyl group Chemical group 0.000 description 4
- 239000004952 Polyamide Substances 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 229910000019 calcium carbonate Inorganic materials 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 238000004821 distillation Methods 0.000 description 3
- 239000012467 final product Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 244000005700 microbiome Species 0.000 description 3
- 229920002647 polyamide Polymers 0.000 description 3
- 238000010992 reflux Methods 0.000 description 3
- 239000011780 sodium chloride Substances 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 241000894007 species Species 0.000 description 2
- 238000013268 sustained release Methods 0.000 description 2
- 239000012730 sustained-release form Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- VLDPXPPHXDGHEW-UHFFFAOYSA-N 1-chloro-2-dichlorophosphoryloxybenzene Chemical compound ClC1=CC=CC=C1OP(Cl)(Cl)=O VLDPXPPHXDGHEW-UHFFFAOYSA-N 0.000 description 1
- 241000251468 Actinopterygii Species 0.000 description 1
- 241000588813 Alcaligenes faecalis Species 0.000 description 1
- 241000195493 Cryptophyta Species 0.000 description 1
- 241000238557 Decapoda Species 0.000 description 1
- 208000012868 Overgrowth Diseases 0.000 description 1
- 241000589614 Pseudomonas stutzeri Species 0.000 description 1
- 229940005347 alcaligenes faecalis Drugs 0.000 description 1
- 150000008064 anhydrides Chemical class 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006065 biodegradation reaction Methods 0.000 description 1
- 230000008033 biological extinction Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- -1 dihydroxypropyl PABA Chemical compound 0.000 description 1
- 238000012851 eutrophication Methods 0.000 description 1
- 239000003337 fertilizer Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000012010 growth Effects 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000029553 photosynthesis Effects 0.000 description 1
- 238000010672 photosynthesis Methods 0.000 description 1
- 230000008635 plant growth Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/34—Biological treatment of water, waste water, or sewage characterised by the microorganisms used
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
- B01J13/02—Making microcapsules or microballoons
- B01J13/06—Making microcapsules or microballoons by phase separation
- B01J13/14—Polymerisation; cross-linking
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/10—Inorganic compounds
- C02F2101/16—Nitrogen compounds, e.g. ammonia
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/10—Biological treatment of water, waste water, or sewage
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Organic Chemistry (AREA)
- Microbiology (AREA)
- Water Supply & Treatment (AREA)
- Environmental & Geological Engineering (AREA)
- Engineering & Computer Science (AREA)
- Hydrology & Water Resources (AREA)
- Biodiversity & Conservation Biology (AREA)
- Dispersion Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Abstract
The application relates to the technical field of water treatment, in particular to a degradable slow-release microsphere for water treatment and a preparation method thereof, comprising the following steps: s1, preparing a modified polyimide porous carrier; s2, strain loading of the porous carrier: adding the modified polyimide porous carrier prepared in the step S1 into a strain solution, soaking for 2-3h, taking out, and drying to obtain microspheres loaded with strains; s3, coating a degradable slow-release film: and (3) adding the microspheres loaded with the strain obtained in the step (S2) into a slow-release film solution, uniformly mixing, and drying to obtain the degradable slow-release microspheres. The slow release microsphere can slowly release strains in water, effectively reduce ammonia nitrogen content in water, has long-term continuous purification effect on water, and reduces sewage treatment cost.
Description
Technical Field
The application relates to the technical field of water treatment, in particular to a degradable slow-release microsphere for water treatment and a preparation method thereof.
Background
The sources of the ammonia nitrogen wastewater mainly comprise a landfill site, chemical fertilizers, pharmacy, petrochemical industry and the like, if the ammonia nitrogen wastewater is not treated to reach the standard and is directly discharged into water, serious threat is caused to the ecological environment, the ammonia nitrogen wastewater is the primary reason for forming water eutrophication, the higher concentration ammonia nitrogen wastewater can slow down the growth of fish and shrimp in water, even can lead to extinction, and causes overgrowth of aquatic plants, the barrier growth of plants on the water surface can prevent algae in the water from photosynthesis, and in addition, the biodegradation of ammonia nitrogen in the water environment also needs to consume a large amount of oxygen, the ammonia nitrogen wastewater can generate competition relationship with aquatic organisms, and the balance and stability of water ecology are further threatened.
In the prior art, a certain microbial agent is often added into a water body for multiple times to achieve a purification effect aiming at the treatment of ammonia nitrogen wastewater, but microorganisms which are directly added into the water body exist in a free mode, so that the microorganisms are seriously lost, cannot be used in the water body for a long time, the purification effect on the ammonia nitrogen wastewater is seriously limited, and the labor cost is greatly increased due to multiple times of addition, so that the resource waste is caused.
Disclosure of Invention
In order to overcome the defects of the prior art, the application provides a preparation method of the degradable slow-release microsphere for water treatment, which can slowly release strains in water, effectively reduce the ammonia nitrogen content in water, achieve the effect of long-term continuous purification on the water, and reduce the cost of sewage treatment.
In order to achieve the above purpose, the technical scheme adopted by the application is as follows:
the application provides a preparation method of a degradable slow-release microsphere for water treatment, which comprises the following steps:
s1, preparation of modified polyimide porous carrier
Dissolving diamine monomer and grafting monomer in N, N-dimethylformamide to obtain a phase A, dispersing nonionic surfactant in liquid paraffin to obtain a phase B, mixing the phase A and the phase B for 1h under stirring to form a nonaqueous emulsion system, adding dianhydride monomer to react for 4-6h to obtain a polymer, adding a mixture of acetic anhydride and pyridine to perform chemical imidization to obtain a precipitate, washing and drying the precipitate, performing thermal imidization to obtain a modified polyimide polymer, and performing heat treatment on the modified polyimide polymer to obtain a modified polyimide porous carrier;
s2, strain loading of porous carrier
Adding the modified polyimide porous carrier prepared in the step S1 into a strain solution, soaking for 2-3h, taking out, and drying to obtain microspheres loaded with strains;
s3, coating of degradable slow-release film
And (3) adding the microspheres loaded with the strain obtained in the step (S2) into a slow-release film solution, uniformly mixing, and drying to obtain the degradable slow-release microspheres.
In some embodiments, the diamine monomer is 3, 5-diaminobenzoic acid or 4,4' -diaminodiphenyl ether and the dianhydride monomer is pyromellitic dianhydride.
Preferably, the diamine monomer is 4,4' -diaminodiphenyl ether and the dianhydride monomer is pyromellitic dianhydride.
In some embodiments, the molar ratio of diamine monomer to dianhydride monomer is 1: (1-1.1).
In some embodiments, the grafting monomer is added in an amount of 25 to 35 weight percent of the dianhydride monomer.
In some embodiments, the grafting monomer is obtained by: polyethylene glycol, 3, 5-diaminobenzoic acid, a catalyst and an entrainer are added into a reactor to react under a protective atmosphere, and crude products are obtained and then extracted and distilled under reduced pressure to obtain grafted monomers.
In some embodiments, the molar ratio of polyethylene glycol to 3, 5-diaminobenzoic acid is 1: (1.25-1.38).
Preferably, the molar ratio of the polyethylene glycol to the 3, 5-diaminobenzoic acid is 1:1.32.
In some embodiments, the polyethylene glycol has an average molecular weight of 400 to 700.
Preferably, the polyethylene glycol has an average molecular weight of 600.
The source of the polyethylene glycol is not particularly limited and can be purchased commercially, including but not limited to, polyethylene glycol from Shanghai, chemical technology, inc.
In some embodiments, the catalyst is p-toluene sulfonic acid.
In some embodiments, the catalyst is used in an amount of 4 to 5.5wt%, preferably 4.8wt% of polyethylene glycol.
In some embodiments, the entrainer is toluene.
Preferably, the entrainer is added in an amount of 120 to 130wt% of polyethylene glycol.
More preferably, the entrainer is added in an amount of 125wt% of polyethylene glycol.
In some embodiments, the nonionic surfactant comprises span 85 and tween 80 in a weight ratio of (1.5-2): 1, preferably 1.8:1.
in some embodiments, the mixture of acetic anhydride and pyridine is added in an amount of 12% by volume of N, N-dimethylformamide and the volume ratio of acetic anhydride to pyridine in the mixture of acetic anhydride and pyridine is 2:1.
In some embodiments, the temperature of the heat treatment in step S1 is 180-195 ℃.
The applicant found in the study that the types and the amounts of diamine monomer, diacid monomer and grafting monomer can have important influence on the quality and pore structure of the prepared porous carrier, and further related to the capability of accommodating strains, the application selects diamine monomer as 4,4' -diaminodiphenyl ether and dianhydride monomer as pyromellitic dianhydride, and the weight ratio of the diamine monomer to the diacid anhydride is 1: (1-1.1), the porous carrier synthesized by combining a specific method has better quality, a larger number of micropore structures and clear pore structures, is more favorable for fixing strains in pores, has larger specific surface area, can keep the strains intact, has excellent ammonia nitrogen removal effect after slow release, probably because the types and the proportions of diamine monomers, dianhydride monomers and grafting monomers can lead more grafting chains to be coated in N, N-dimethylformamide liquid drops in the polymerization process, groups on the grafting monomers can be entangled and adsorbed on the polyamide acid main chain with groups in a polyamide acid structure through hydrogen bonds, increases the volume of the N, N-dimethylformamide liquid drops, can be cured into polyamide acid particles in the chemical imidization process, can lead the particle size of the final modified polyimide carrier to be increased rapidly through chemical imidization small liquid, can not be mutually adhered, can lead the grafting structures to be decomposed through the heat treatment of specific temperature, and can form more modified polyimide carrier structures, thereby being favorable for long-term and clear loading of the strains.
In some embodiments, the bacterial species solution comprises at least one of nitrifying bacteria, denitrifying bacteria, bacillus subtilis, and desulfurizing bacillus.
Preferably, the strain solution comprises a mixture of nitrifying bacteria, denitrifying bacteria and bacillus subtilis, and the ratio of the living bacteria to the bacillus subtilis is 1: (0.8-1.2): (1-1.5).
The nitrifying bacteria are nitrifying bacteria, and the denitrifying bacteria comprise at least one of Pseudomonas mendocina, alcaligenes faecalis and Pseudomonas stutzeri.
In some embodiments, the live bacterial count of the bacterial species solution is 10 10 CFU/g。
In some embodiments, the slow release film solution comprises, in mass percent: 5-10% of sodium alginate, 5-10% of gelatin, 3-7% of polyvinyl alcohol, 0.8-1.5% of methyl-pentapolyethylene glycol-succinimidyl acrylate, 0.5-1.5% of dihydroxypropyl PABA ethyl ester and the balance of water.
Preferably, the slow-release film solution comprises the following components in percentage by mass: 8% of sodium alginate, 8% of gelatin, 5% of polyvinyl alcohol, 1.1% of methyl-pentapolyethylene glycol-succinimidyl acrylate, 1% of dihydroxypropyl PABA ethyl ester and the balance of water.
In some embodiments, the slow release film solution is obtained by the steps of: mixing sodium alginate and water, dissolving in water bath at 50deg.C, adding gelatin, heating to 85deg.C to dissolve, adding polyvinyl alcohol under stirring to dissolve, adding methyl-pentapolyethylene glycol-succinimidyl acrylate and dihydroxypropyl PABA ethyl ester, and mixing uniformly to obtain the slow-release membrane solution.
Methyl-pentapolyethylene glycol-succinimidyl acrylate has a CAS number of 1449390-12-8 and dihydroxypropyl PABA ethyl ester has a CAS number of 58882-17-0.
In some embodiments, the polyvinyl alcohol has a degree of polymerization of 1799, an alcoholysis degree of 98-98, and an average molecular weight of 44.05.
The source of the polyvinyl alcohol is not particularly limited and can be purchased commercially, including but not limited to, polyvinyl alcohol from Shanghai Hengfi Biotech Co.
In some embodiments, the gelatin is an industrial gelatin, commercially available, including but not limited to, commercially available from Shangshui county Fuyuan gelatin Inc.
In order to ensure that the microbial strains can be slowly released in the water body to achieve the effect of long-acting treatment on sewage, a layer of slow-release film is formed on the surface of the porous carrier for loading the microbial strains, so that the microspheres have excellent slow-release performance after being added into the water, and the slow-release film for water treatment in the prior art is generally excessively fast in degradation speed and not easy to degrade, so that the slow-release film for releasing the microbial strains is slow in water purification effect, and the applicant finds that the slow-release film formed by adopting specific components is used for coating the porous carrier for loading the microbial strains after a large amount of researches, so that the slow-release microspheres formed by adopting the slow-release film for coating the porous carrier for loading the microbial strains have moderate degradation speed in the water body, excellent slow-release performance, and the effect of long-acting purification can be achieved on the basis of ensuring better ammonia nitrogen removal effect, and the interaction between the slow-release film and a molecular chain generated by methyl-pentapolyethylene glycol-succinyl ester and dihydroxypropyl PABA in the slow-release film solution system under the heating condition can weaken the degradation speed to a certain extent, so that the slow-release speed of the slow-release microspheres can be relatively slow in the water body and have relatively long-acting effect.
The application also provides the degradable slow-release microsphere for water treatment obtained by the preparation method.
Compared with the prior art, the application has the beneficial effects that:
(1) According to the application, the types and the proportions of diamine monomers and dianhydride monomers are regulated, and the grafting monomers synthesized by a specific method and heat treatment are combined, so that the obtained porous carrier has better quality, more micropore structures and clear pore channel structures, bacterial fixing in holes is facilitated, the bacterial can be kept intact due to larger specific surface area, and the porous carrier has excellent ammonia nitrogen removal effect after slow release;
(2) The slow-release membrane formed by adopting the specific components is used for coating the porous carrier loaded with the microbial strains, so that the slow-release microsphere formed by the specific components has moderate degradation speed in water, excellent slow-release performance and long-acting purification effect on the basis of ensuring better ammonia nitrogen removal effect.
Detailed Description
The technical solutions of the present application will be clearly and completely described in connection with the embodiments, and it is obvious that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
Example 1
The preparation method of the degradable slow-release microsphere for water treatment comprises the following steps:
s1, preparation of modified polyimide porous carrier
Dissolving diamine monomer and grafting monomer in N, N-dimethylformamide to obtain phase A, dispersing nonionic surfactant in liquid paraffin to obtain phase B, mixing the phase A and the phase B under stirring to form a nonaqueous emulsion system, adding dianhydride monomer to react for 5 hours to obtain a polymer, adding a mixture of acetic anhydride and pyridine to perform chemical imidization to obtain a precipitate, washing and drying the precipitate, performing thermal imidization at the temperature of 300 ℃ to obtain a modified polyimide polymer, and performing heat treatment at the temperature of 190 ℃ for 1 hour to obtain a modified polyimide porous carrier;
the molar ratio of the diamine monomer to the dianhydride monomer is 1:1.07, the diamine monomer is 4,4' -diaminodiphenyl ether, the dianhydride monomer is pyromellitic dianhydride, and the addition amount of the grafting monomer is 30wt% of the dianhydride monomer;
the grafting monomer is obtained by the following steps: adding polyethylene glycol, 3, 5-diaminobenzoic acid, a catalyst and an entrainer in a molar ratio of 1:32 into a reactor, carrying out reflux reaction at 120 ℃ for 6.5 hours under a protective atmosphere to obtain a crude product, adding calcium carbonate to adjust pH to neutrality, extracting for 3 times by using dichloromethane and sodium chloride solution, and finally distilling off the solvent by reduced pressure distillation to obtain a grafted monomer;
polyethylene glycol was purchased from Shanghai, meter Hui chemical technology Co., ltd, and had an average molecular weight of 600; the catalyst is p-toluenesulfonic acid, and the dosage of the catalyst is 4.8wt% of polyethylene glycol; the entrainer is toluene, and the addition amount of the entrainer is 125wt% of polyethylene glycol;
the ratio of the amount of N, N-dimethylformamide added to the amount of diamine monomer added was 12.5ml:1g;
the nonionic surfactant comprises span 85 and tween 80, and the weight ratio of the span 85 to the tween 80 is 1.8:1, a step of;
the addition amount of the mixture of the acetic anhydride and the pyridine is 12 percent of the volume of the N, N-dimethylformamide, and the volume ratio of the acetic anhydride to the pyridine in the mixture of the acetic anhydride and the pyridine is 2:1;
s2, strain loading of porous carrier
Adding the modified polyimide porous carrier prepared in the step S1 into a strain solution, soaking for 2.5 hours, taking out, and drying to obtain microspheres loaded with strains;
the viable count of the strain solution is 10 10 CFU/g；
The strain solution is a mixture of nitrifying bacteria, denitrifying bacteria and bacillus subtilis, and the ratio of the viable bacteria to the strain solution is 1:1:1.25; the nitrifying bacteria are nitrifying bacteria, and the denitrifying bacteria are Pseudomonas mendocina;
s3, coating of degradable slow-release film
And (3) adding the microspheres loaded with the strain obtained in the step (S2) into a slow-release film solution, uniformly mixing, and drying to obtain the degradable slow-release microspheres.
The slow-release film solution comprises the following components in percentage by mass: 8% of sodium alginate, 8% of gelatin, 5% of polyvinyl alcohol, 1.1% of methyl-pentapolyethylene glycol-succinimidyl acrylate, 1% of dihydroxypropyl PABA ethyl ester and the balance of water.
The slow release film solution is obtained by the following steps: mixing sodium alginate and water, dissolving in water bath at 50deg.C, adding gelatin, heating to 85deg.C to dissolve, adding polyvinyl alcohol under stirring to dissolve, adding methyl-pentapolyethylene glycol-succinimidyl acrylate and dihydroxypropyl PABA ethyl ester, mixing, standing, and cooling below 30deg.C to obtain the final product.
The polyvinyl alcohol has a polymerization degree of 1799, an alcoholysis degree of 98-98%, an average molecular weight of 44.05, and is purchased from Shanghai Hengfi Biotechnology Co., ltd; gelatin is industrial gelatin, purchased from Shangshui county Fuyuan gelatin Co.
Example 2
The preparation method of the degradable slow-release microsphere for water treatment comprises the following steps:
s1, preparation of modified polyimide porous carrier
Dissolving diamine monomer and grafting monomer in N, N-dimethylformamide to obtain phase A, dispersing nonionic surfactant in liquid paraffin to obtain phase B, mixing the phase A and the phase B under stirring to form a nonaqueous emulsion system, adding dianhydride monomer to react for 5 hours to obtain a polymer, adding a mixture of acetic anhydride and pyridine to perform chemical imidization to obtain a precipitate, washing and drying the precipitate, performing thermal imidization at the temperature of 300 ℃ to obtain a modified polyimide polymer, and performing heat treatment at the temperature of 190 ℃ for 1 hour to obtain a modified polyimide porous carrier;
the molar ratio of the diamine monomer to the dianhydride monomer is 1:1, the diamine monomer is 3, 5-diaminobenzoic acid, the dianhydride monomer is pyromellitic dianhydride, and the addition amount of the grafting monomer is 25wt% of the dianhydride monomer;
the grafting monomer is obtained by the following steps: adding polyethylene glycol, 3, 5-diaminobenzoic acid, a catalyst and an entrainer in a molar ratio of 1:1.32 into a reactor, carrying out reflux reaction at 120 ℃ for 6.5 hours under a protective atmosphere to obtain a crude product, adding calcium carbonate to adjust pH to neutrality, extracting for 3 times with dichloromethane and sodium chloride solution, and finally distilling off the solvent by reduced pressure distillation to obtain a grafted monomer;
polyethylene glycol was purchased from Shanghai, meter Hui chemical technology Co., ltd, and had an average molecular weight of 600; the catalyst is p-toluenesulfonic acid, and the dosage of the catalyst is 4wt% of polyethylene glycol; the entrainer is toluene, and the addition amount of the entrainer is 120wt% of polyethylene glycol;
the ratio of the amount of N, N-dimethylformamide added to the amount of diamine monomer added was 12.5ml:1g;
the nonionic surfactant comprises span 85 and tween 80, and the weight ratio of the span 85 to the tween 80 is 1.8:1, a step of;
the addition amount of the mixture of the acetic anhydride and the pyridine is 12 percent of the volume of the N, N-dimethylformamide, and the volume ratio of the acetic anhydride to the pyridine in the mixture of the acetic anhydride and the pyridine is 2:1;
s2, strain loading of porous carrier
Adding the modified polyimide porous carrier prepared in the step S1 into a strain solution, soaking for 2.5 hours, taking out, and drying to obtain microspheres loaded with strains;
the viable count of the strain solution is 10 10 CFU/g；
The strain solution is a mixture of nitrifying bacteria, denitrifying bacteria and bacillus subtilis, and the ratio of the viable bacteria to the strain solution is 1:1:1.25; the nitrifying bacteria are nitrifying bacteria, and the denitrifying bacteria are Pseudomonas mendocina;
s3, coating of degradable slow-release film
And (3) adding the microspheres loaded with the strain obtained in the step (S2) into a slow-release film solution, uniformly mixing, and drying to obtain the degradable slow-release microspheres.
The slow-release film solution comprises the following components in percentage by mass: 10% of sodium alginate, 5% of gelatin, 3% of polyvinyl alcohol, 1.5% of methyl-pentapolyethylene glycol-succinimidyl acrylate, 0.5% of dihydroxypropyl PABA ethyl ester and the balance of water.
The slow release film solution is obtained by the following steps: mixing sodium alginate and water, dissolving in water bath at 50deg.C, adding gelatin, heating to 85deg.C to dissolve, adding polyvinyl alcohol under stirring to dissolve, adding methyl-pentapolyethylene glycol-succinimidyl acrylate and dihydroxypropyl PABA ethyl ester, mixing, standing, and cooling below 30deg.C to obtain the final product.
The polyvinyl alcohol has a polymerization degree of 1799, an alcoholysis degree of 98-98%, an average molecular weight of 44.05, and is purchased from Shanghai Hengfi Biotechnology Co., ltd; gelatin is industrial gelatin, purchased from Shangshui county Fuyuan gelatin Co.
Example 3
The preparation method of the degradable slow-release microsphere for water treatment comprises the following steps:
s1, preparation of modified polyimide porous carrier
Dissolving diamine monomer and grafting monomer in N, N-dimethylformamide to obtain phase A, dispersing nonionic surfactant in liquid paraffin to obtain phase B, mixing the phase A and the phase B under stirring to form a nonaqueous emulsion system, adding dianhydride monomer to react for 5 hours to obtain a polymer, adding a mixture of acetic anhydride and pyridine to perform chemical imidization to obtain a precipitate, washing and drying the precipitate, performing thermal imidization at the temperature of 300 ℃ to obtain a modified polyimide polymer, and performing heat treatment at the temperature of 190 ℃ for 1 hour to obtain a modified polyimide porous carrier;
the molar ratio of the diamine monomer to the dianhydride monomer is 1:1.1, the diamine monomer is 3, 5-diaminobenzoic acid, the dianhydride monomer is pyromellitic dianhydride, and the addition amount of the grafting monomer is 35wt% of the dianhydride monomer;
the grafting monomer is obtained by the following steps: adding polyethylene glycol, 3, 5-diaminobenzoic acid, a catalyst and an entrainer in a molar ratio of 1:1.38 into a reactor, carrying out reflux reaction at 120 ℃ for 6.5 hours under a protective atmosphere to obtain a crude product, adding calcium carbonate to adjust pH to neutrality, extracting for 3 times with dichloromethane and sodium chloride solution, and finally distilling off the solvent by reduced pressure distillation to obtain a grafted monomer;
polyethylene glycol was purchased from Shanghai, meter Hui chemical technology Co., ltd, and had an average molecular weight of 600; the catalyst is p-toluenesulfonic acid, and the dosage of the catalyst is 5.5wt% of polyethylene glycol; the entrainer is toluene, and the addition amount of the entrainer is 130wt% of polyethylene glycol;
the ratio of the amount of N, N-dimethylformamide added to the amount of diamine monomer added was 12.5ml:1g;
the nonionic surfactant comprises span 85 and tween 80, and the weight ratio of the span 85 to the tween 80 is 1.8:1, a step of;
the addition amount of the mixture of the acetic anhydride and the pyridine is 12 percent of the volume of the N, N-dimethylformamide, and the volume ratio of the acetic anhydride to the pyridine in the mixture of the acetic anhydride and the pyridine is 2:1;
s2, strain loading of porous carrier
Adding the modified polyimide porous carrier prepared in the step S1 into a strain solution, soaking for 2.5 hours, taking out, and drying to obtain microspheres loaded with strains;
the viable count of the strain solution is 10 10 CFU/g；
The strain solution is a mixture of nitrifying bacteria, denitrifying bacteria and bacillus subtilis, and the ratio of the viable bacteria to the strain solution is 1:1:1.25; the nitrifying bacteria are nitrifying bacteria, and the denitrifying bacteria are Pseudomonas mendocina;
s3, coating of degradable slow-release film
And (3) adding the microspheres loaded with the strain obtained in the step (S2) into a slow-release film solution, uniformly mixing, and drying to obtain the degradable slow-release microspheres.
The slow-release film solution comprises the following components in percentage by mass: sodium alginate 5%, gelatin 10%, polyvinyl alcohol 7%, methyl-pentapolyethylene glycol-succinimidyl acrylate 0.8%, dihydroxypropyl PABA ethyl ester 1.5%, and water the rest.
The slow release film solution is obtained by the following steps: mixing sodium alginate and water, dissolving in water bath at 50deg.C, adding gelatin, heating to 85deg.C to dissolve, adding polyvinyl alcohol under stirring to dissolve, adding methyl-pentapolyethylene glycol-succinimidyl acrylate and dihydroxypropyl PABA ethyl ester, mixing, standing, and cooling below 30deg.C to obtain the final product.
The polyvinyl alcohol has a polymerization degree of 1799, an alcoholysis degree of 98-98%, an average molecular weight of 44.05, and is purchased from Shanghai Hengfi Biotechnology Co., ltd; gelatin is industrial gelatin, purchased from Shangshui county Fuyuan gelatin Co.
Example 4
The present example provides a method for preparing a degradable sustained release microsphere for water treatment, and the specific embodiment is the same as example 1, except that the grafting monomer is added in an amount of 40wt% of the dianhydride monomer.
Example 5
The present example provides a method for preparing a degradable sustained release microsphere for water treatment, and the specific embodiment is the same as example 1, except that the grafting monomer is added in an amount of 20wt% of the dianhydride monomer.
Example 6
This example provides a method for preparing a degradable slow release microsphere for water treatment, and the specific embodiment is the same as example 1, except that the temperature of the heat treatment is 200 ℃.
Example 7
The present example provides a method for preparing a degradable slow-release microsphere for water treatment, and the specific embodiment is the same as example 1, except that polyvinyl alcohol is not added into the slow-release film solution.
Performance testing
1. Water purifying effect
The degradable slow-release microspheres prepared in the examples 1-7 are used for treating wastewater of a landfill, wherein the ammonia nitrogen concentration in the wastewater is 600mg/L, and the COD value is 2000mg/L.
The testing method comprises the following steps: 7 groups of wastewater are respectively added into a glass container with the specification of 0.5mX0.4mX0.5m, the circulating flow state of the water body is maintained, the slow release microspheres are respectively added into each group, the adding amount is 1% of the weight of the wastewater, the ammonia nitrogen concentration and the COD value in the wastewater at the same time period after 1 day, 14 days and 30 days are respectively recorded, and the results are recorded in table 1.
TABLE 1
As can be seen from the data of table 1, the slow release microspheres of examples 1 to 3 have better ammonia nitrogen removal and COD reduction effects, and are known to have excellent slow release properties according to the ammonia nitrogen concentration and COD content on days 1, 14 and 30, and examples 4 and 5 have a certain influence on slow release properties and wastewater purification effects due to the change of the addition amount of the graft monomer, and the addition amount of the graft monomer of example 4 is increased, so that a large amount of microorganisms are released in the early stage, and the purification effects on days 1 and 14 are better, while the purification effects on day 30 are relatively poor, and the addition amount of the graft monomer of example 5 is reduced, so that the slow release properties are poor, further affecting the ammonia nitrogen removal and COD reduction effects thereof; in example 6, the porous structure of the porous carrier is changed due to the change of the heat treatment temperature, so that the slow release performance is further influenced, but the influence on the final purification effect is not great according to the ammonia nitrogen concentration and COD content on the 30 th day; example 7 the slow release performance was relatively deteriorated due to the absence of polyvinyl alcohol added to the slow release film solution, and further the effect of removing ammonia nitrogen and reducing COD was deteriorated.
Finally, it should be noted that the above-mentioned embodiments are only for illustrating the technical solution of the present application, and not for limiting the same, and although the present application has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications and equivalents may be made to the technical solution of the present application without departing from the spirit and scope of the technical solution of the present application, and all such modifications and equivalents are intended to be encompassed in the scope of the claims of the present application.
Claims (10)
1. The preparation method of the degradable slow-release microsphere for water treatment is characterized by comprising the following steps of:
s1, preparation of modified polyimide porous carrier
Dissolving diamine monomer and grafting monomer in N, N-dimethylformamide to obtain a phase A, dispersing nonionic surfactant in liquid paraffin to obtain a phase B, mixing the phase A and the phase B under stirring to form a nonaqueous emulsion system, adding dianhydride monomer to react for 4-6 hours to obtain a polymer, adding a mixture of acetic anhydride and pyridine to perform chemical imidization to obtain a precipitate, washing and drying the precipitate, performing thermal imidization to obtain a modified polyimide polymer, and performing heat treatment on the modified polyimide polymer to obtain a modified polyimide porous carrier;
s2, strain loading of porous carrier
Adding the modified polyimide porous carrier prepared in the step S1 into a strain solution, soaking for 2-3h, taking out, and drying to obtain microspheres loaded with strains;
s3, coating of degradable slow-release film
And (3) adding the microspheres loaded with the strain obtained in the step (S2) into a slow-release film solution, uniformly mixing, and drying to obtain the degradable slow-release microspheres.
2. The method for preparing the degradable slow release microspheres for water treatment according to claim 1, wherein the diamine monomer is 3, 5-diaminobenzoic acid or 4,4' -diaminodiphenyl ether, and the dianhydride monomer is pyromellitic dianhydride.
3. The method for preparing the degradable slow release microspheres for water treatment according to claim 2, wherein the molar ratio of the diamine monomer to the dianhydride monomer is 1: (1-1.1).
4. The method for preparing the degradable slow release microspheres for water treatment according to claim 2, wherein the grafting monomer is added in an amount of 25-35wt% of the dianhydride monomer.
5. The method for preparing the degradable slow release microspheres for water treatment according to claim 1, wherein the grafting monomer is obtained by the following steps: polyethylene glycol, 3, 5-diaminobenzoic acid, a catalyst and an entrainer are added into a reactor to react under a protective atmosphere, and crude products are obtained and then extracted and distilled under reduced pressure to obtain grafted monomers.
6. The method for preparing the degradable slow release microsphere for water treatment according to claim 5, wherein the molar ratio of polyethylene glycol to 3, 5-diaminobenzoic acid is 1: (1.25-1.38).
7. The method for preparing the degradable slow release microsphere for water treatment according to claim 1, wherein the temperature of the heat treatment in the step S1 is 180-195 ℃.
8. The method for preparing the degradable slow-release microspheres for water treatment according to claim 1, wherein the strain solution comprises at least one of nitrifying bacteria, denitrifying bacteria, bacillus subtilis and desulfurizing bacillus.
9. The method for preparing the degradable slow release microsphere for water treatment according to claim 1, wherein the slow release film solution comprises the following components in percentage by mass: 5-10% of sodium alginate, 5-10% of gelatin, 3-7% of polyvinyl alcohol, 0.8-1.5% of methyl-pentapolyethylene glycol-succinimidyl acrylate, 0.5-1.5% of dihydroxypropyl PABA ethyl ester and the balance of water.
10. A degradable slow release microsphere for water treatment obtained by the preparation method according to any one of claims 1 to 9.
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