MABR hollow fiber composite membrane as well as preparation method and application thereof

Abstract

The invention relates to the technical field of sewage treatment, in particular to an MABR hollow fiber composite membrane and a preparation method and application thereof.The preparation method comprises the following steps that raw materials, a reinforcing agent and a dispersing agent are put into a kneading machine to be kneaded for 1-2 hours, a modifying agent is put into the kneading machine, the mixture is heated to 80-120 DEG C and kneaded for 4 hours, and a modified material is obtained; the preparation method comprises the following steps: uniformly mixing a modified material, a catalyst, a cross-linking agent and a solution to prepare mixed slurry with the solid content of 5-40%, coating the slurry on the surface of a hollow fiber tube, and curing to obtain the MABR hollow fiber membrane, so that the mechanical strength of a basic raw material is improved through a reinforcing agent, the membrane is not easy to damage, and the service life of the membrane is prolonged. According to the present invention, the reinforcing agent and other auxiliary agents are uniformly dispersed in the basic raw material through the dispersant so as to reduce defects, the raw material end-capping group is modified through the modifier so as to provide the product with characteristics of aging resistance and good biocompatibility, and the reaction speed is changed during the molding process through the catalyst so as to form the stable membrane structure through the molding cross-linking of the cross-linking agent and the raw material;

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a MABR hollow fiber composite membrane and a preparation method and application thereof. Background Art

[0002] Membrane Aeration Bio-film Reactor (MABR) is a new type of efficient sewage treatment process that combines the traditional biofilm reactor process with gas membrane separation technology. MABR technology has the advantages of high oxygen transmission efficiency, low process energy consumption, good operational flexibility, modular and easy integration, etc., and has received more and more attention in the fields of sewage treatment and water body remediation.

[0003] The MABR process is different from the traditional bubbling aeration method. It uses gas membrane for bubble-free aeration. After oxygen passes through the membrane, it is directly utilized by the microorganisms covering the membrane surface. While keeping the gas pressure lower than the membrane bubble point pressure, air or pure oxygen can enter the water body in the form of molecules. Therefore, the efficiency of microorganisms in utilizing oxygen is much higher than that of traditional aeration processes.

[0004] The gas membrane plays two main roles in the MABR process, namely, providing a carrier for the growth of microorganisms and providing a source of oxygen for the microorganisms attached to the membrane surface. Therefore, the MABR hollow fiber membrane must have the following basic properties: low mass transfer resistance and high oxygen permeability, good mechanical properties and bioaffinity.

[0005] At present, there are two main types of membranes actually used in the MABR process:

[0006] (1) Hydrophobic microporous membranes, represented by PTFE hollow fiber membranes and polypropylene (PP) hollow fiber membranes. Due to the hydrophobicity, the membrane pores are not wetted by water, that is, water cannot spontaneously enter the membrane pores of the hydrophobic microporous membrane, but the oxygen in the gas phase can directly diffuse into the biofilm and be used by microorganisms. Hydrophobic microporous membranes have the advantages of low mass transfer resistance and high oxygen transfer efficiency, but the disadvantages are that the bubble point range is small and the control is difficult. In addition, as the use time increases, the micropores may be clogged by the secretions of microorganisms, causing the membrane pores to be wetted and contaminated, and the gas mass transfer resistance increases dramatically, thereby affecting the efficient conduct of the MABR process;

[0007] (2) Homogeneous dense membrane. Dense membranes are generally made of selectively permeable materials. Since the dense membrane structure has no micropores, there is no need to worry about pollution and clogging. However, its fatal weakness is that the transfer of oxygen is completely controlled by the dissolution diffusion coefficient of the membrane material, and the oxygen mass transfer efficiency is low. In addition, this type of material also has the disadvantages of high cost, poor mechanical strength, and easy wire breakage during use, which limits its large-scale practical application.

[0008] In view of the above problems, people have tried to develop a composite membrane by combining the structures of the above two membranes, that is, a selectively permeable membrane with high permeability composed of a selectively permeable skin layer and a porous support layer. Theoretically, the composite membrane is the most suitable membrane for the MABR process, but due to improper material selection, the cross-linked product has a large number of defects and it is difficult to form a dense structure. Summary of the invention

[0009] In order to overcome the deficiencies of the prior art, one of the objects of the present invention is to provide a MABR hollow fiber composite membrane and a preparation method and application thereof.

[0010] One of the purposes of the present invention is achieved by the following technical solution:

[0011] A method for preparing a MABR hollow fiber composite membrane comprises the following steps:

[0012] S1: Put the raw materials, reinforcing agent and dispersant into a kneader and knead for 1-2 hours, add the modifier, heat to 80-120°C, and knead for 4 hours to obtain the modified material;

[0013] S2: uniformly mixing the modified material, catalyst, cross-linking agent and solution to prepare a mixed slurry with a solid content of 5% to 40%;

[0014] S3: coating the slurry on the surface of the hollow fiber tube and curing it to obtain the MABR hollow fiber membrane.

[0015] Furthermore, the raw materials in step S1 include at least one of the following: methyl silicone oil, vinyl silicone oil, phenyl silicone oil, fluorosilicone rubber;

[0016] Further, the reinforcing agent includes at least one of the following: white carbon black, kaolin, diatomaceous earth, and silicon powder;

[0017] Further, the dispersant includes: KH530, KH550, titanate;

[0018] Further, the modifier includes: polyurethane, epoxy resin, silicone resin;

[0019] Further, the catalyst is at least one of the following: platinum catalyst, bis 2-4, bis 2-5;

[0020] Further, the cross-linking agent is at least one of the following: hydrogen-containing silicone oil, octamethylcyclotetrasiloxane;

[0021] Further, the cross-linking agent is at least one of the following: toluene, xylene, cyclohexane, hexane;

[0022] Furthermore, the hollow fiber tube is at least one of the following: PET, PTFE, PES, PVDF, PP, PI.

[0023] Furthermore, in step S3, the curing is performed by keeping the temperature at 60-100° C. for 60-120 minutes, or by heating at 180-280° C. for 3-10 minutes.

[0024] According to another aspect of the present invention, a MABR hollow fiber composite membrane is provided, which is prepared by the above-mentioned preparation method.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] An application of a MABR hollow fiber composite membrane in MABR sewage treatment, wherein the MABR hollow fiber composite membrane is applied to MABR sewage treatment to achieve aerobic and anaerobic microbial degradation;

[0027] The mechanical strength of the basic raw materials is increased by reinforcing agents, making the membrane less likely to break;

[0028] Dispersants are used to make reinforcing agents and other additives more evenly dispersed in the basic raw materials to reduce defects;

[0029] Modify the end groups of raw materials through modifiers to make the products more resistant to aging and have better bioaffinity;

[0030] Change the reaction rate through the catalyst during the forming process;

[0031] A stable membrane structure is formed by cross-linking the cross-linking agent and the raw materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a formula table of an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] See also Figure 1 , the present invention provides the following technical solutions:

[0035] Embodiment 1:

[0036] A method for preparing a MABR hollow fiber composite membrane comprises the following steps:

[0037] S1: Put the raw material, reinforcing agent and dispersing agent into a kneading machine and knead for 1-2 hours, add the modifier, heat to 80-120°C, and knead for 4 hours to obtain a modified material, wherein the raw material is 60% methyl silicone oil, the reinforcing agent is 25% white carbon black and 5% silicon powder, and the dispersing agent is 2% KH550;

[0038] S2: The modifier, catalyst, crosslinking agent and solution are uniformly mixed to prepare a mixed slurry with a solid content of 5%-40%, wherein the modifier is 5% epoxy resin, the catalyst is 1% platinum catalyst, the crosslinking agent is 2% hydrogenated silicone oil, and the solution is toluene (solid content 30 WT%);

[0039] S3: The slurry is coated on the surface of the hollow fiber tube and cured to obtain a MABR hollow fiber membrane, wherein the hollow fiber tube is PP0.5 / / 0.8mm, the curing temperature is 70°C, and the curing time is 100 minutes.

[0040] The MABR hollow fiber composite membrane prepared by the above method has a membrane thickness of 100-150 μm, an inner diameter of 0.5 mm, and an outer diameter of 1.0 mm.

[0041] Embodiment 2:

[0042] A method for preparing a MABR hollow fiber composite membrane comprises the following steps:

[0043] S1: Put the raw material, reinforcing agent and dispersing agent into a kneading machine and knead for 1-2 hours, add the modifier, heat to 80-120°C, and knead for 4 hours to obtain a modified material, wherein the raw material is 55% methyl silicone oil, the reinforcing agent is 30% white carbon black and 3% diatomaceous earth, and the dispersing agent is 2.5% KH550;

[0044] S2: The modifier, catalyst, crosslinking agent and solution are uniformly mixed to form a mixed slurry with a solid content of 5%-40%, wherein the modifier is 5% silicone resin and 2% polyurethane, the catalyst is 0.5% platinum catalyst, the crosslinking agent is 2.5% hydrogenated silicone oil, and the solution is xylene (solid content 15 WT%);

[0045] S3: The slurry is coated on the surface of the hollow fiber tube and cured to obtain a MABR hollow fiber membrane, wherein the hollow fiber tube is PET1.0 / 1.8mm, the curing temperature is 90°C, and the curing time is 60 minutes.

[0046] The MABR hollow fiber composite membrane prepared by the above method has a membrane thickness of 20-50 μm, an inner diameter of 1.0 mm, and an outer diameter of 1.9 mm.

[0047] Embodiment 3:

[0048] A method for preparing a MABR hollow fiber composite membrane comprises the following steps:

[0049] S1: Put the raw material, reinforcing agent and dispersing agent into a kneading machine and knead for 1-2 hours, add the modifier, heat to 80-120°C, and knead for 4 hours to obtain a modified material, wherein the raw material is 62% vinyl silicone oil, the reinforcing agent is 25% white carbon black and 3% kaolin, and the dispersing agent is 2.5% KH550;

[0050] S2: The modifier, catalyst, crosslinking agent and solution are uniformly mixed to form a mixed slurry with a solid content of 5%-40%, wherein the modifier is 5% silicone resin, the catalyst is 2% di-pentane catalyst, the crosslinking agent is 1% octamethylcyclotetrasiloxane, and the solution is xylene (solid content 25 WT%);

[0051] S3: The slurry is coated on the surface of the hollow fiber tube and cured to obtain a MABR hollow fiber membrane, wherein the hollow fiber tube is PET1.0 / 1.8mm, the curing temperature is 145°C, and the curing time is 30 minutes.

[0052] The MABR hollow fiber composite membrane prepared by the above method has a membrane thickness of 50-80 μm, an inner diameter of 1.0 mm, and an outer diameter of 2.0 mm.

[0053] Embodiment 4:

[0054] A method for preparing a MABR hollow fiber composite membrane comprises the following steps:

[0055] S1: Put the raw material, reinforcing agent and dispersing agent into a kneading machine and knead for 1-2 hours, add the modifier, heat to 80-120°C, and knead for 4 hours to obtain a modified material, wherein the raw material is 58% phenyl silicone oil, the reinforcing agent is 25% white carbon black and 5% silicon powder, and the dispersing agent is 2% titanate;

[0056] S2: The modifier, catalyst, crosslinking agent and solution are uniformly mixed to form a mixed slurry with a solid content of 5%-40%, wherein the modifier is 3% epoxy resin and 3% silicone resin, the catalyst is 2.5% di-2-5 catalyst, the crosslinking agent is 1.5% hydrogenated silicone oil, and the solution is cyclohexane (solid content 12%);

[0057] S3: The slurry is coated on the surface of the hollow fiber tube and cured to obtain a MABR hollow fiber membrane, wherein the hollow fiber tube is PTFE1.0 / 1.3mm, the curing temperature is 160°C, and the curing time is 20 minutes.

[0058] The MABR hollow fiber composite membrane prepared by the above method has a membrane thickness of 20-40 μm, an inner diameter of 1.0 mm, and an outer diameter of 1.4 mm.

[0059] Embodiment 5:

[0060] A method for preparing a MABR hollow fiber composite membrane comprises the following steps:

[0061] S1: Put the raw material, reinforcing agent and dispersing agent into a kneading machine and knead for 1-2 hours, add the modifier, heat to 80-120°C, and knead for 4 hours to obtain a modified material, wherein the raw material is 58% phenyl silicone oil, the reinforcing agent is 25% white carbon black and 5% silicon powder, and the dispersing agent is 2% titanate;

[0062] S2: The modifier, catalyst, crosslinking agent and solution are uniformly mixed to form a mixed slurry with a solid content of 5%-40%, wherein the modifier is 3% epoxy resin and 3% silicone resin, the catalyst is 2.5% di-2-5 catalyst, the crosslinking agent is 1.5% hydrogenated silicone oil, and the solution is xylene (solid content 20%);

[0063] S3: The slurry is coated on the surface of the hollow fiber tube and cured to obtain a MABR hollow fiber membrane, wherein the hollow fiber tube is PI2.4 / 3.0 mm, the curing temperature is 260° C., and the curing time is 10 minutes.

[0064] The MABR hollow fiber composite membrane prepared by the above method has a membrane thickness of 60-90 μm, an inner diameter of 2.4 mm, and an outer diameter of 3.4 mm.

[0065] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0066] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0067] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0069] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0070] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a MABR hollow fiber composite membrane, characterized in that: The steps include: S1: Put the raw materials, reinforcing agent and dispersant into a kneader and knead for 1-2 hours, add the modifier, heat to 80-120°C, and knead for 4 hours to obtain the modified material; S2: uniformly mix the modified material, catalyst, cross-linking agent and solution to prepare a mixed slurry with a solid content of 5%-40%; S3: coating the slurry on the surface of the hollow fiber tube and curing it to obtain the MABR hollow fiber membrane.

2. The method for preparing a MABR hollow fiber composite membrane according to claim 1, characterized in that: The raw materials in step S1 include at least one of the following: methyl silicone oil, vinyl silicone oil, phenyl silicone oil, and fluorosilicone rubber.

3. The method for preparing a MABR hollow fiber composite membrane according to claim 1, characterized in that: The reinforcing agent includes at least one of the following: white carbon black, kaolin, diatomaceous earth, and silicon powder; The dispersants include: KH530, KH550, and titanate; The modifier includes: polyurethane, epoxy resin, silicone resin; The catalyst is at least one of the following: platinum catalyst, bis 2-4, bis 2-5; The cross-linking agent is at least one of the following: hydrogen-containing silicone oil, octamethylcyclotetrasiloxane; The cross-linking agent is at least one of the following: toluene, xylene, cyclohexane, hexane; The hollow fiber tube is at least one of the following: PET, PTFE, PES, PVDF, PP, and PI.

4. The method for preparing a MABR hollow fiber composite membrane according to claim 1, characterized in that: In step S3, the curing is carried out by keeping the temperature at 60-100° C. for 60-120 minutes, or by heating at 180-280° C. for 3-10 minutes.

5. A MABR hollow fiber composite membrane, characterized in that: The MABR hollow fiber composite membrane is prepared by the preparation method of a MABR hollow fiber composite membrane according to any one of claims 1 to 4, and the inner diameter of the MABR hollow fiber composite membrane is 300 to 3000 μm and the wall thickness is 10 to 300 μm.

6. Use of the MABR hollow fiber composite membrane as claimed in claim 5 in sewage treatment.

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