Electrospun composite membrane for slow release of bacterial quorum-sensing signal molecules and preparation method and application thereof

Abstract

The application discloses an electrospun composite membrane for slow release of bacterial population response signal molecules and a preparation method and application thereof, and belongs to the field of sewage biological treatment. The application provides an electrospun composite membrane for slow release of bacterial population response signal molecules and a preparation method and application thereof. The composite membrane comprises a base membrane obtained by electrospinning and a functional layer, the functional layer is a fiber with a core-shell structure, the shell layer is a polymer, the core layer is a polymer containing bacterial population response signal molecule material, the base membrane is obtained by uniaxial electrospinning technology, and the functional layer is obtained by uniaxial emulsion electrospinning or coaxial electrospinning technology. The obtained composite membrane has good air permeability, high oxygen transfer rate, large specific surface area and high roughness, which provides favorable conditions for microbial adhesion, and when the composite membrane is used for assembling a flat membrane module and applied to an MABR process, an excellent ammonia nitrogen removal rate can be obtained.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of sewage biological treatment, and particularly relates to an electrospun composite membrane for slow release of bacterial population response signal molecules and a preparation method and application thereof. BACKGROUND

[0002] The total amount of sewage treatment in China is large, and the content of nitrogen source pollution such as ammonia nitrogen and total nitrogen is high, so the difficulty of sewage treatment is great. The nitrogen source pollution in sewage is generally removed through the nitrification-denitrification pathway. As the executor of the nitrification reaction, nitrifying bacteria have the characteristics of long generation time and difficulty in enrichment. How to quickly domesticate the biological bacterial population of sewage treatment and shorten the cycle of forming nitrification function is a problem worth studying.

[0003] The carrier commonly used in sewage biological treatment is generally an inert high polymer material, which only passively provides attachment space for microorganisms and cannot actively regulate the population activity of microorganisms. Although there have been some experimental works of loading bacterial population response signal molecules on the surface of the carrier, the loading method is relatively simple, which often causes burst release of the bacterial population response signal molecules, and the effective period of the bacterial population response signal molecules in the material to function is short. The form of embedding the bacterial population response signal molecules in the carrier in the prior art can play a certain slow release effect, but it is restricted by the diameter of the electrospun fibers, and the embedded bacterial population response signal molecules are not easy to release. SUMMARY

[0004] In view of the above defects and deficiencies, the present application provides an electrospun composite membrane for slow release of bacterial population response signal molecules and a preparation method and application thereof.

[0005] The technical scheme of the present application is as follows:

[0006] One of the purposes of the present application is to provide an electrospun composite membrane for slow release of bacterial population response signal molecules, which comprises a base membrane obtained by electrospinning and a functional layer. The functional layer is a fiber with a core-shell structure, the shell layer is a polymer, and the core layer is a polymer containing bacterial population response signal molecule material.

[0007] Further limited, the base membrane material is one or a mixture of several of polyethylene (PE), polypropylene (PP), polyurethane (PU), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), and polydimethylsiloxane (PDMS) in any ratio.

[0008] Further limited, the polymer is one or several of poly-lactic acid (PLA), polyethylene oxide (PEO), polycaprolactone (PCL), polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), poly-lactic acid-glycolic acid copolymer (PLGA), poly-lactic acid-polyethylene glycol (PLA-PEG), poly(caprolactone ethyl ethylene phosphate) (PCLEEP) in any ratio mixture.

[0009] Further limited, the bacterial population response signal molecule material is one or several of caproyl-L-homoserine lactone (C6-HSL), octanoyl-L-homoserine lactone (C8-HSL), dodecanoyl-L-homoserine lactone (C12-HSL), N-3-oxododecanoyl-L-homoserine lactone (3-O-C12-HSL) in any ratio mixture.

[0010] Further limited, the mass ratio of the polymer to the bacterial population quorum sensing signal molecule material in the core layer is (1-25):(0.1-5).

[0011] The second object of the present application is to provide a preparation method of an electrospun composite membrane for slow release of bacterial population response signal molecules, which is carried out according to the following steps:

[0012] S1: configure the base film material into a first polymer solution, and prepare a base film by uniaxial electrospinning;

[0013] S2: configure the functional layer polymer into a second polymer solution containing bacterial population response signal molecule material, and prepare a functional layer with core-shell structure fibers by uniaxial emulsion electrospinning to obtain a composite membrane.

[0014] Further limited, the mass concentration of the first polymer solution in S1 is 8-20%.

[0015] Further limited, the uniaxial electrospinning parameters in S1 are: temperature 20-25℃, humidity 40-60%, voltage 15-30KV, push injection speed 5-50μL / min, nozzle diameter 0.1-1mm.

[0016] Further limited, the mass concentration of the polymer in the second polymer solution in S2 is 1-25%, and the mass concentration of the bacterial population response signal molecule material is 0.1-5%.

[0017] Further limited, the uniaxial emulsion electrospinning parameters in S2 are: temperature 20-25℃, humidity 40-60%, voltage 15-30KV, push injection speed 5-50μL / min, nozzle diameter 0.1-1mm.

[0018] The third object of the present application is to provide a preparation method of the electrospun composite membrane for slow release of bacterial quorum sensing signal molecules, which is carried out according to the following steps:

[0019] S1: configuring a base film material into a first polymer solution and preparing a base film by uniaxial electrospinning;

[0020] S2: configuring a functional layer polymer into a second polymer solution and a third polymer solution containing bacterial quorum sensing signal molecule material respectively, and preparing a functional layer with a core-shell structure fiber by coaxial electrospinning to obtain a composite membrane.

[0021] Further limitation, the mass concentration of the first polymer solution in S1 is 8-20%.

[0022] Further limitation, the uniaxial electrospinning parameters in S1 are: temperature 20-25℃, humidity 40-60%, voltage 15-30KV, push injection speed 5-50μL / min, and nozzle diameter 0.1-1mm.

[0023] Further limitation, the mass concentration of the second polymer solution in S2 is 10-25%.

[0024] Further limitation, the mass concentration of the polymer in the third polymer solution in S2 is 1-25%, and the mass concentration of the bacterial quorum sensing signal molecule material is 0.1-5%.

[0025] Further limitation, the coaxial electrospinning parameters in S2 are: temperature 20-25℃, humidity 40-60%, voltage 15-30KV, push injection speed 5-50μL / min, inner diameter of nozzle 0.1-0.8mm, and outer diameter of nozzle 0.2-1mm.

[0026] The fourth object of the present application is to provide an application of the electrospun composite membrane for slow release of bacterial quorum sensing signal molecules in MABR process.

[0027] The fifth object of the present application is to provide a flat sheet membrane module, which comprises the electrospun composite membrane for slow release of bacterial quorum sensing signal molecules.

[0028] Compared with the prior art, the present application has the following advantages:

[0029] (1) The present application adopts the design of core-shell structure fiber, the shell layer adopts biodegradable polymer material, the core layer is bacterial population response signal molecule, along with the process of shell layer biodegradation, the bacterial population response signal molecule is gradually released, which plays a slow-release role of core-shell fiber. Since the electrospun functional layer is formed by the core-shell fiber interlaced in three-dimensional space, and the degradation of the shell layer only occurs at the interface in contact with the biofilm, the sustainability and stability of the slow-release effect are further ensured.

[0030] (2) The electrospun composite membrane prepared by the present application has large specific surface area and high roughness, which provides favorable conditions for microbial adhesion.

[0031] (3) The electrospun composite membrane prepared by the present application has the function of slow-releasing bacterial population response signal molecules, which can release bacterial population response signal molecules in a long time span compared with burst release carriers.

[0032] (4) The bacterial population response signal molecules released by the electrospun composite membrane prepared by the present application help to enrich nitrifying bacteria in the early stage of startup, and can strengthen the metabolism of nitrifying bacteria in the stable period, thereby improving the removal rate of ammonia nitrogen. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a scanning electron microscope photo of the electrospun base film in Example 1;

[0034] Figure 2 is a transmission electron microscope photo of the core-shell fiber of the electrospun functional layer in Example 1;

[0035] Figure 3 Application Example Influent and effluent ammonia nitrogen concentration;

[0036] Figure 4 Application Example Bacterial quorum sensing information molecule concentration in effluent. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below in combination with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0038] The first specific embodiment of the present application provides a preparation method of an electrospun composite membrane for slow-releasing bacterial population response signal molecules, which is carried out according to the following steps:

[0039] (1) configure the base film material into a first polymer solution; wherein the base film material is one or more of polyethylene (PE), polypropylene (PP), polyurethane (PU), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), and polydimethylsiloxane (PDMS), and the concentration of the first polymer solution is 8-20wt%.

[0040] (2) install the first polymer solution on an electrospinning device, and prepare a base film by uniaxial electrospinning; wherein the uniaxial electrospinning parameters are: a voltage of 15-30KV, a push injection speed of 5-50μL / min, and a nozzle diameter of 0.1-1mm.

[0041] (3) configure the functional layer polymer into a second polymer solution containing bacterial population response signal molecule materials; wherein the functional layer polymer is one or more of polylactic acid (PLA), polyethylene oxide (PEO), polycaprolactone (PCL), polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polylactic acid-glycolic acid copolymer (PLGA), polylactic acid-polyethylene glycol (PLA-PEG), and poly(caprolactone ethyl ethylene phosphate) (PCLEEP), the bacterial population response signal molecule materials are one or more of caproyl-L-homoserine lactone (C6-HSL), octanoyl-L-homoserine lactone (C8-HSL), dodecanoyl-L-homoserine lactone (C12-HSL), and N-3-oxododecanoyl-L-homoserine lactone (3-O-C12-HSL), the concentration of the functional layer polymer in the second polymer solution is 1-25wt%, and the concentration of the bacterial population response signal molecule materials is 0.1-5wt%.

[0042] (4) prepare a functional layer with a core-shell structure fiber by uniaxial emulsion electrospinning of the second polymer solution containing bacterial population response signal molecule materials, to obtain a composite film; wherein the uniaxial emulsion electrospinning parameters are: a voltage of 15-30KV, a push injection speed of 5-50μL / min, and a nozzle diameter of 0.1-1mm.

[0043] The second specific embodiment of the present application provides a preparation method of an electrospinning composite film for slow release of bacterial population response signal molecules, which is performed according to the following steps:

[0044] (1) configure the base film material into a first polymer solution; wherein the base film material is one or more of polyethylene (PE), polypropylene (PP), polyurethane (PU), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), and polydimethylsiloxane (PDMS), and the concentration of the first polymer solution is 8-20wt%.

[0045] (2) install the first polymer solution on the electrospinning device, and prepare the base film by uniaxial electrospinning; wherein the uniaxial electrospinning parameters are: voltage 15-30KV, push injection speed 5-50μL / min, and nozzle diameter 0.1-1mm.

[0046] (3) configure the functional layer polymer into a second polymer solution respectively; wherein the functional layer polymer is one or several of polylactic acid (PLA), polyethylene oxide (PEO), polycaprolactone (PCL), polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polylactic acid-glycolic acid copolymer (PLGA), polylactic acid-polyethylene glycol (PLA-PEG), and poly(caprolactone ethyl ethylene phosphate) (PCLEEP), and the concentration of the second polymer solution is 10-25wt%.

[0047] (4) configure the functional layer polymer into a third polymer solution containing bacterial population response signal molecule material respectively; wherein the functional layer polymer is one or several of polylactic acid (PLA), polyethylene oxide (PEO), polycaprolactone (PCL), polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polylactic acid-glycolic acid copolymer (PLGA), polylactic acid-polyethylene glycol (PLA-PEG), and poly(caprolactone ethyl ethylene phosphate) (PCLEEP), the bacterial population response signal molecule material is one or several of caproyl-L-homoserine lactone (C6-HSL), octanoyl-L-homoserine lactone (C8-HSL), dodecanoyl-L-homoserine lactone (C12-HSL), and N-3-oxododecanoyl-L-homoserine lactone (3-O-C12-HSL), the concentration of the polymer in the third polymer solution is 1-25wt%, and the concentration of the bacterial population response signal molecule material is 0.1-5wt%.

[0048] (5) install the second polymer solution and the third polymer solution containing bacterial population response signal molecule material on the electrospinning device respectively, and prepare the functional layer with core-shell structure fiber by coaxial electrospinning to obtain the composite film; wherein the coaxial electrospinning parameters are: voltage 15-30KV, push injection speed 5-50μL / min, inner diameter of nozzle 0.1-0.8mm, and outer diameter of nozzle 0.2-1mm.

[0049] The third embodiment of the present application provides an electrospun composite membrane of the slow-released bacterial population response signal molecule obtained by the preparation method according to the first and second embodiments, the electrospun composite membrane comprising a base membrane obtained by electrospinning and a functional layer, the functional layer being a fiber with a core-shell structure, the shell layer being a polymer, and the core layer being a polymer containing the bacterial population response signal molecule material, wherein the base membrane fibers are crosslinked with each other in three-dimensional space to form a crosslinked channel structure.

[0050] The fourth embodiment of the present application provides an application of the electrospun composite membrane obtained by the preparation method according to the first and second embodiments in a MABR process.

[0051] The fifth embodiment of the present application provides a flat membrane module comprising the electrospun composite membrane of the slow-released bacterial population response signal molecule obtained by the preparation method according to the first and second embodiments.

[0052] Hereinafter, the present application will be further described in detail with reference to examples.

[0053] In the following examples, the experimental methods used are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained by commercial channels by those skilled in the art.

[0054] In the following examples, the term "comprising", "including", "having", "containing" or any other variant thereof is intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but can include other elements not expressly listed or inherent to such composition, step, method, article, or apparatus.

[0055] When a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values for an equivalent, concentration, or other value or parameter is expressed, it should be understood that all ranges formed by any pairings of an upper limit or preferred value of any range with a lower limit or preferred value of any range, whether or not the range is expressly disclosed, are specifically disclosed. For example, when a range "1 to 5" is disclosed, the described range should be interpreted to include ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include the end values and all integers and fractions within that range. In the specification and claims of the present application, range definitions can be combined and / or interchanged, unless otherwise stated, and these ranges include all sub-ranges contained therein.

[0056] The indefinite articles "a" and "an," as used herein in the specification, unless clearly indicated to the contrary, along with the use of "comprising" or "containing" to describe one embodiment of the application, allow for various embodiments of the application to include, but not be limited to, one or more elements, features, structures, and / or characteristics. Furthermore, unless otherwise specified, the use of the indefinite article "a" or "an" can refer to one or more than one, and the singular can also include the plural (for example, a can mean one, or one or more, or one or more than one). The indefinite article "a" or "an" thus, is used herein in the specification to include one or more than one, and the singular form is intended to mean the plural unless the number clearly indicates only the singular.

[0057] Example 1

[0058] The preparation method of the electrospun composite membrane of the slow-release bacterial population response signal molecule of the present embodiment is carried out according to the following steps:

[0059] (1) A PVDF solution with a concentration of 12wt% is prepared as a first polymer solution.

[0060] (2) The first polymer solution is installed on an electrospinning device, and a PVDF base film is prepared by uniaxial electrospinning under the conditions of a temperature of 25°C, a humidity of 60% RH, a voltage of 15KV, a push injection speed of 8μL / min, and a nozzle diameter of 0.5mm. The scanning electron microscope (SEM) image of the obtained PVDF base film is shown in FIG. 1, from which it can be seen that the average diameter of the electrospun fibers is 280nm, and the fibers intersect with each other in three-dimensional space to form an intersecting and interconnected pore structure. Figure 1

[0061] (3) A PLA solution with a concentration of 15wt% is prepared as a second polymer solution.

[0062] (4) A PLA / C6-HSL solution with a PLA concentration of 10wt% and a C6-HSL concentration of 2wt% is prepared as a third polymer solution containing a bacterial population response signal molecule material.

[0063] (5) The second polymer solution and the third polymer solution containing the bacterial population response signal molecule material are respectively installed on an electrospinning device, and a PLA / C6-HSL functional layer with a core-shell structure fiber is prepared on the basis of the base film by coaxial electrospinning under the conditions of a temperature of 25°C, a humidity of 45% RH, a voltage of 15KV, a push injection speed of 8μL / min, an inner diameter of the nozzle of 0.3mm, and an outer diameter of the nozzle of 0.6mm, to obtain a PVDF-PLA / C6-HSL composite membrane. The transmission electron microscope (TEM) image of the core-shell fiber of the obtained PLA / C6-HSL functional layer is shown in FIG. 2, from which it can be seen that the diameter of the shell layer is 538nm, and the diameter of the core layer is 458nm. Figure 2

[0064] Example 2

[0065] The preparation method of the electrospun composite membrane of the slow-release bacterial population response signal molecule of the present embodiment is carried out according to the following steps:

[0066] ​​(1) Prepare a PTFE solution with a concentration of 10wt% as a first polymer solution.

[0067] (2) Install the first polymer solution on an electrospinning device, and prepare a PTFE base film by uniaxial electrospinning under the conditions of a temperature of 25°C, a humidity of 50% RH, a voltage of 18KV, a push injection speed of 8μL / min, and a nozzle diameter of 0.5mm.

[0068] (3) Prepare a PEO solution with a concentration of 15wt% as a second polymer solution.

[0069] (4) Prepare a PEO / C12-HSL solution with a PEO concentration of 12wt% and a C12-HSL concentration of 1.5wt% as a third polymer solution containing a bacterial population response signal molecule material.

[0070] (5) Install the second polymer solution and the third polymer solution containing a bacterial population response signal molecule material on an electrospinning device, and prepare a PEO / C12-HSL functional layer with a core-shell structure fiber on the basis of the base film by coaxial electrospinning under the conditions of a temperature of 25°C, a humidity of 45% RH, a voltage of 15KV, a push injection speed of 8μL / min, an inner diameter of the nozzle of 0.3mm, and an outer diameter of the nozzle of 0.6mm, to obtain a PTFE-PEO / C12-HSL composite membrane.

[0071] Control Example: In this control example, a PVDF hollow fiber membrane produced by a certain company is used.

[0072] Application Example:

[0073] The specific application parameters of the membrane materials in the pilot plant equipment in Example 1, Example 2, and the control example are shown in the following table.

[0074] Table 1. Operation parameters of the pilot plant equipment

[0075] Item Parameter Membrane material Example 1 or Example 2 or Control Membrane module packing area 96.8 m 2 / m 3 ]]> Operating gas pressure 20 kPa Gas flow rate 400 ml / min Reactor effective volume 15L

[0076] The PVDF-PLA / C6-HSL composite membrane of Example 1 and the PTFE-PEO / C12-HSL composite membrane of Example 2 are respectively assembled into flat sheet membrane modules, and the hollow fiber membrane of the control example is assembled into a hollow fiber membrane module, which are applied in a sewage biological treatment pilot plant equipment. The specific water inlet composition is: chemical oxygen demand (COD) of 300mg / L, ammonia nitrogen of 30mg / L, and total phosphorus of 5mg / L. The ammonia nitrogen concentrations of the water inlet and outlet are as follows: Figure 3As shown in the table, it can be seen that the water quality of the water of the examples 1 and 2 reaches stability on the 14th day, while the water quality of the water of the control example reaches stability on the 15th day, and the average ammonia nitrogen of the water of the examples 1 and 2 is 0.33 mg / L and 0.36 mg / L respectively in the 25-40 days after stability, while the average ammonia nitrogen of the water of the control example is 5.28 mg / L.

[0077] The bacterial quorum sensing information molecules in the water of the pilot plant of the examples 1 and 2 are detected, and the concentration in the water is shown in the table. Figure 4 As shown in the table, the bacterial quorum sensing information molecules released from the membrane material gradually increase with the operation of the pilot plant, and the concentration of the water of the examples 1 and 2 reaches the peak on the 26th day and the 28th day respectively, and then gradually decreases, and it can be seen that a better slow-release effect is achieved within 40 days.

[0078] The above is only the preferred specific embodiments of the present application, these specific embodiments are different implementations based on the overall concept of the present application, and the protection scope of the present application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An electrospun composite membrane that releases a bacterial quorum-sensing signal molecule at a controlled rate, characterized in that, It comprises a base film obtained by electrospinning and a functional layer, the functional layer is a fiber with a core-shell structure, the shell layer is a polymer, the core layer is a polymer containing a bacterial quorum sensing signal molecule, the base film material is one or more of PE, PP, PU, PVDF, PTFE, PDMS, the polymer is one or more of PLA, PEO, PCL, PEG, PVA, PVP, PLGA, PLA-PEG, PCLEEP, the bacterial quorum sensing signal molecule is one or more of C6-HSL, C8-HSL, C12-HSL, 3-O-C12-HSL, and the electrospun composite membrane for slow release of bacterial quorum sensing signal molecules is applied in the MABR process.

2. The composite film according to claim 1, characterized by, The mass ratio of the polymer in the core layer to the bacterial quorum sensing signal molecule is (1-25):(0.1-5).

3. The method of producing an electrospun composite membrane according to any one of claims 1 to 2, characterized in that, The following steps are performed: S1: configure the base film material into a first polymer solution, and prepare the base film by uniaxial electrospinning; S2: configure the functional layer polymer into a second polymer solution containing a bacterial quorum sensing signal molecule, and prepare the functional layer with core-shell structure fibers by uniaxial emulsion electrospinning to obtain the composite membrane.

4. The method of claim 3, wherein, The concentration of the first polymer solution in S1 is 8-20wt%, the uniaxial electrospinning parameters are: voltage 15-30KV, push injection speed 5-50μL / min, nozzle diameter 0.1-1mm, the concentration of the polymer in the second polymer solution in S2 is 1-25wt%, the concentration of the bacterial quorum sensing signal molecule is 0.1-5wt%, and the uniaxial emulsion electrospinning parameters are: voltage 15-30KV, push injection speed 5-50μL / min, nozzle diameter 0.1-1mm.

5. The method of producing an electrospun composite membrane according to any one of claims 1 to 2, characterized in that, The following steps are performed: S1: configure the base film material into a first polymer solution, and prepare the base film by uniaxial electrospinning; S2: configure the functional layer polymer into a second polymer solution and a third polymer solution containing a bacterial quorum sensing signal molecule, and prepare the functional layer with core-shell structure fibers by coaxial electrospinning to obtain the composite membrane.

6. The method of claim 5, wherein, The concentration of the first polymer solution in S1 is 8-20wt%, the uniaxial electrospinning parameters are: voltage 15-30KV, push injection speed 5-50μL / min, nozzle diameter 0.1-1mm, the concentration of the second polymer solution in S2 is 10-25wt%, the concentration of the polymer in the third polymer solution is 1-25wt%, the concentration of the bacterial quorum sensing signal molecule is 0.1-5wt%, and the coaxial electrospinning parameters in S2 are: voltage 15-30KV, push injection speed 5-50μL / min, inner diameter of the nozzle 0.1-0.8mm, outer diameter of the nozzle 0.2-1mm.

7. The electrospun composite membrane for slow release of bacterial quorum sensing signal molecules according to any one of claims 1-2 is applied in the MABR process.

8. A flat sheet membrane module characterized by, It comprises the electrospun composite membrane for slow release of bacterial quorum sensing signal molecules according to any one of claims 1-2.

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