A confined catalytic ceramic membrane module and a preparation method thereof, and a confined catalytic ceramic membrane nanoreactor

Abstract

The application discloses a limited catalytic ceramic membrane assembly and a preparation method thereof, and a limited catalytic ceramic membrane nanoreactor. The limited catalytic ceramic membrane assembly comprises a limited catalytic ceramic membrane and a flat plate porous ceramic membrane support body, the limited catalytic ceramic membrane is stacked on the flat plate porous ceramic membrane support body, and the circumference of the limited catalytic ceramic membrane is sealingly fixed with the circumference of the flat plate porous ceramic membrane support body; the limited catalytic ceramic membrane comprises a double-pass porous alumina membrane and a catalyst, and the catalyst is loaded in the pores of the double-pass porous alumina membrane and on the surface thereof. The limited catalytic ceramic membrane nanoreactor comprises the limited catalytic ceramic membrane assembly. The application can improve the strength and stability of the limited catalytic ceramic membrane, solve the problem that the alumina membrane is prone to breakage in actual application, and can stably and efficiently catalyze a high-level oxidation reaction to remove various new pollutants in water in water treatment.

Description

Technical Field

[0001] This invention relates to the field of novel membrane filtration technology, and in particular to a confined catalytic ceramic membrane module and its preparation method, and a confined catalytic ceramic membrane nanoreactor. Background Technology

[0002] Due to the potential adverse effects of emerging pollutants (such as pharmaceuticals and personal care products, endocrine disruptors, etc.) on ecosystems and human health, there is an urgent need to achieve efficient removal of these pollutants in water treatment processes. However, traditional wastewater treatment methods are insufficient to effectively remove these trace amounts of emerging pollutants. Advanced oxidation processes (AOPs) can generate various highly reactive oxygen species, effectively removing emerging pollutants from water, making them a promising new pollutant treatment technology in the new era of water treatment. However, traditional AOPs suffer from numerous technical bottlenecks that urgently need to be overcome, including high oxidant dosage in homogeneous systems, low utilization rate of reactive oxygen species, poor oxidation selectivity, easy catalyst aggregation, and difficulties in recovery and regeneration.

[0003] In recent years, confined catalytic ceramic membrane technology, which constructs nanoscale confined spaces and couples them with membrane filtration, has provided a new direction for the efficient removal of new pollutants. The enrichment of reactive oxygen species and reactants, and the enhancement of mass transfer under confinement can significantly improve the utilization rate of reactive oxygen species and the removal rate of new pollutants. However, current confined catalytic ceramic membranes are still mainly porous membranes in a particle-packed state, which suffer from drawbacks such as poor pore uniformity, small confined space volume, easy membrane rupture, low catalytic efficiency, poor catalytic stability, and low flux variation, which urgently need to be overcome, making it difficult to fully realize the advantages of the confinement effect.

[0004] It should be noted that the information disclosed in the background section above is only for understanding the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a confined catalytic ceramic membrane module and its preparation method, as well as a confined catalytic ceramic membrane nanoreactor.

[0006] The present invention adopts the following technical solution:

[0007] In a first aspect, a confined catalytic ceramic membrane assembly is provided, comprising a confined catalytic ceramic membrane and a flat porous ceramic membrane support, wherein the confined catalytic ceramic membrane is stacked on the flat porous ceramic membrane support, and the circumferential direction of the confined catalytic ceramic membrane is sealed and fixed to the circumferential direction of the flat porous ceramic membrane support; the confined catalytic ceramic membrane comprises a dual-channel porous alumina membrane and a catalyst, wherein the catalyst is loaded in the pores of the dual-channel porous alumina membrane and on its surface.

[0008] In a second aspect, a method for preparing the confined catalytic ceramic membrane module described in the first aspect is provided, comprising the following steps:

[0009] S1. Clean the double-pass porous alumina membrane with pores perpendicular to the membrane surface and evenly distributed, and set it aside for later use.

[0010] S2. Prepare catalyst precursor solution. Immerse the double-pass porous alumina membrane from step S1 into the catalyst precursor solution so that the catalyst precursor solution is fully adsorbed onto the surface and pores of the double-pass porous alumina membrane. Then, treat it by hydrothermal method to obtain a confined catalytic ceramic membrane, clean and dry it for later use.

[0011] S3. The confined catalytic ceramic membrane obtained in step S2 is sealed and fixed to the flat porous ceramic membrane support in the circumferential direction.

[0012] Thirdly, a confined catalytic ceramic membrane nanoreactor is proposed, comprising the confined catalytic ceramic membrane assembly described in the first aspect, an upper shell, an inlet, a lower shell, and an outlet; the upper shell and the lower shell are fixed to form a closed reaction chamber, the confined catalytic ceramic membrane assembly is fixed in the central region of the reaction chamber, the inlet is located on the upper shell and above the confined catalytic ceramic membrane in the confined catalytic ceramic membrane assembly, and the outlet is located on the lower shell and below the flat porous ceramic membrane support in the confined catalytic ceramic membrane assembly; the inner wall of the upper shell has an oblique region that gradually narrows from the confined catalytic ceramic membrane to the inlet.

[0013] The present invention has the following beneficial effects:

[0014] In this invention, the dual-channel porous alumina membrane possesses highly regular, uniform, and adjustable pores, providing a uniform and precise nano-confined space to enhance mass transfer of reactive oxygen species and the transfer of reaction electrons, maximizing the utilization of the confinement effect. Simultaneously, the vertically elongated pores of the confined catalytic ceramic membrane allow water flow through the membrane layer with low resistance, achieving high membrane flux. Loading catalysts on the surface and within the pores can improve the reaction rate and removal rate of new pollutants in heterogeneous advanced oxidation processes. Combining the confined catalytic ceramic membrane of this invention with a flat porous ceramic membrane support significantly improves the strength and stability of the confined catalytic ceramic membrane, solving the problem of easy breakage of the dual-channel porous alumina membrane. The confined catalytic ceramic membrane module and confined catalytic ceramic membrane nanoreactor of this invention can be widely used in various water treatment applications such as drinking water and medical wastewater treatment, stably and efficiently removing various new pollutants from water bodies.

[0015] More specifically, the present invention has the following advantages:

[0016] (1) The confined catalytic ceramic membrane module and the confined catalytic ceramic membrane nanoreactor can maximize the utilization of the confinement effect. The confined catalytic ceramic membrane module and the confined catalytic ceramic membrane nanoreactor of the present invention are mainly prepared by a dual-channel porous alumina membrane. The confined catalytic ceramic membrane has uniform pore size, short-range ordered pore arrangement, and independent pores, which provides an ideal confinement space for confined catalytic reactions. By combining the inherent pore size of the alumina membrane and controlling the catalyst loading parameters, the confinement scale of the confined catalytic ceramic membrane module and the confined catalytic ceramic membrane nanoreactor can be precisely controlled, thereby maximizing the utilization of the confinement effect based on the scale dependence theory of the confinement effect, enhancing the mass transfer of free radicals and the transfer of reaction electrons, and improving the treatment effect of new pollutants. At the same time, the vertical long straight pores of the confined catalytic ceramic membrane allow water to pass through the membrane layer with low resistance, achieving a win-win situation for flux and treatment effect.

[0017] (2) Confined catalytic ceramic membranes have strong catalytic stability. Catalysts confined within the pores of a double-channel porous alumina membrane have stronger catalytic stability and advantages such as being less prone to dissolution and detachment.

[0018] (3) The confined catalytic ceramic membrane nanoreactor exhibits excellent stability. A flat porous ceramic membrane with high mechanical strength and chemical stability is used as the support for the confined catalytic ceramic membrane. Both are sealed and fixed circumferentially. The inner wall of the upper shell has an oblique region that gradually narrows from the confined catalytic ceramic membrane to the inlet (i.e., the inlet chamber expands from the inlet to the confined catalytic ceramic membrane). This oblique inlet chamber allows for uniform dispersion of incoming water, reducing the physical impact of water on the surface of the confined catalytic ceramic membrane. Under dead-end filtration, this overcomes the drawback of the confined catalytic ceramic membrane being prone to breakage. The confined catalytic ceramic membrane nanoreactor of this invention can increase the operating pressure of the confined catalytic ceramic membrane to above -40 kPa.

[0019] (4) High catalytic activity: In a preferred embodiment, the highly catalytically active mono- or multi-component transition metal oxide supported on the confined catalytic ceramic membrane can efficiently catalyze a variety of oxidants widely used in water treatment, such as ozone, hydrogen peroxide, and persulfate. The confined catalytic ceramic membrane has high catalytic activity for various advanced oxidation processes, but not limited to, such as hydrogen peroxide, ozone, persulfate, ozone / hydrogen peroxide, and hydrogen peroxide / persulfate, thereby achieving enhanced removal of new pollutants in actual water treatment during the coupling process with advanced oxidation reactions.

[0020] (5) In a preferred embodiment, the flat porous ceramic membrane support, the confined catalytic ceramic membrane, the upper shell and the lower shell are fixed by sealant, which can ensure that no leakage occurs during filtration and prevent membrane rupture caused by overtightening of bolts in traditional sealing methods. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the confined catalytic ceramic membrane nanoreactor in Example 1 of the present invention.

[0022] Figure 2a This is a scanning electron microscope (SEM) image of the cross-section of the confined catalytic ceramic membrane of Example 1 of the present invention.

[0023] Figure 2b This is a scanning electron microscope image of the surface of the confined catalytic ceramic membrane of Example 1 of the present invention.

[0024] Figure 3 This is a graph showing the results of removing ibuprofen from water using the confined catalytic ceramic membrane nanoreactor in Example 2 of this invention. Detailed Implementation

[0025] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope or application of the invention. Unless otherwise specified, the embodiments and features described in this application can be combined with each other. In this document, "room temperature" refers to 20-25°C.

[0026] This invention provides a confined catalytic ceramic membrane assembly, comprising a confined catalytic ceramic membrane and a flat porous ceramic membrane support. The confined catalytic ceramic membrane is stacked on the flat porous ceramic membrane support, and the circumferential direction of the confined catalytic ceramic membrane is sealed and fixed to the circumferential direction of the flat porous ceramic membrane support. The confined catalytic ceramic membrane comprises a dual-channel porous alumina membrane and a catalyst, wherein the catalyst is loaded in the pores of the dual-channel porous alumina membrane and on its surface.

[0027] By fixing the confined catalytic ceramic membrane to the flat porous ceramic membrane support in the circumferential direction, the gap between the confined catalytic ceramic membrane and the flat porous ceramic membrane support after fixing is less than 1mm. The unfixed area of ​​both allows water to flow through with low resistance. When the confined catalytic ceramic membrane module is applied to water treatment, it can be ensured that the confined catalytic ceramic membrane is not easily broken and can better exert its catalytic efficiency.

[0028] In some embodiments, the circumferential direction of the confined catalytic ceramic membrane is bonded and sealed to the circumferential direction of the flat porous ceramic membrane support by a sealant.

[0029] In some embodiments, the thickness of the dual-channel porous alumina film is 10-100 μm, and the pores on the dual-channel porous alumina film that are perpendicular to the film surface and uniformly distributed have a pore size of 10-100 nm (e.g., pore sizes of 10-20 nm, 20-30 nm, 40-70 nm, 80-100 nm, etc.) and a pore spacing of 10-100 nm.

[0030] In some embodiments, the catalyst is a mono- or multi-component transition metal oxide with high catalytic activity, and the catalyst loading in the confined catalytic ceramic membrane is 0.5 wt%-5 wt%. Preferably, the particle size of the catalyst is 5-20 nm. Preferably, the mono-component transition metal oxide is at least one of MnO, CuO, FeO, ZnO, and TiO; and the multi-component transition metal oxide is at least one of CuMnO, FeMnO, TiMnO, ZnMnO, CuFeMnO, CuZnMnO, CuTiMnO, and TiMnFeO.

[0031] In some embodiments, the thickness of the flat porous ceramic membrane support is 1-2 mm, and the average pore size is 1-3 μm; the material of the flat porous ceramic membrane support is alumina, or a mixture of alumina and silicon dioxide (silicon dioxide mass content ≤40%). The flat porous ceramic membrane support can be formed by stacking and sintering the above materials.

[0032] This invention also provides a method for preparing a confined catalytic ceramic membrane module, comprising the following steps:

[0033] S1. Clean the double-pass porous alumina membrane with pores perpendicular to the membrane surface and evenly distributed, and set it aside for later use.

[0034] S2. Prepare a catalyst precursor solution (preferably, the concentration ratio of each metal ion in the precursor solution conforms to the metal element ratio of spinel AB2O4 or perovskite ABO3 metal oxides). Immerse the double-pass porous alumina membrane from step S1 into the catalyst precursor solution, so that the catalyst precursor solution is fully adsorbed onto the surface and pores of the double-pass porous alumina membrane. Then, treat it by hydrothermal method to obtain a confined catalytic ceramic membrane, clean and dry it for later use.

[0035] S3. The confined catalytic ceramic membrane obtained in step S2 is sealed and fixed to the flat porous ceramic membrane support in the circumferential direction.

[0036] In some embodiments, the fixing mentioned in step S3 refers to bonding with sealant.

[0037] In some embodiments, in step S2: the precursor solution comprises 1 wt%-5 wt% of a catalyst precursor and 95 wt%-99 wt% of an organic solvent; preferably, the catalyst precursor is at least one of manganese nitrate, ferric nitrate, cobalt nitrate, copper nitrate, titanium nitrate, manganese sulfate, ferric sulfate, cobalt sulfate, copper sulfate, and titanium sulfate; the organic solvent is at least one of methanol, acetonitrile, ethanol, and ethylene glycol; the adsorption refers to: immersing the double-channel porous alumina membrane in the catalyst precursor solution at room temperature and continuously shaking it on a shaker for 1-20 hours, or immersing the double-channel porous alumina membrane in the catalyst precursor solution at room temperature and treating it under low-power ultrasound for 1-60 minutes, so that the catalyst precursor is loaded onto the surface and pores of the double-channel porous alumina membrane; the hydrothermal process is: heating to 100-200℃ at a heating rate of 1-5℃ / min and reacting for 3-5 hours.

[0038] A specific embodiment of the present invention also provides a confined catalytic ceramic membrane nanoreactor, comprising an upper shell, an inlet, a lower shell, and an outlet of the confined catalytic ceramic membrane assembly; the upper shell and the lower shell are fixed to form a closed reaction chamber, the confined catalytic ceramic membrane assembly is fixed in the central region of the reaction chamber, the inlet is located on the upper shell and above the confined catalytic ceramic membrane in the confined catalytic ceramic membrane assembly, and the outlet is located on the lower shell and below the flat porous ceramic membrane support in the confined catalytic ceramic membrane assembly; the inner wall of the upper shell has an oblique region that gradually narrows from the confined catalytic ceramic membrane to the inlet.

[0039] The dual-channel porous alumina membrane has long, straight nanopores along the vertical direction of the membrane sheet. The pores are short-range ordered and parallel to each other. This uniform and ordered nanopore structure is beneficial for fully utilizing the confinement effect, enhancing the mass transfer of free radicals and the transfer of reaction electrons, and improving the treatment effect of new pollutants. It is also beneficial for increasing membrane flux. However, the dual-channel porous alumina membrane is brittle and prone to breakage when applied to membrane reactors. To address this, the present invention designs the aforementioned confined catalytic ceramic membrane nanoreactor. During water filtration, the flat porous ceramic membrane support can effectively bear and disperse the stress applied to the confined catalytic ceramic membrane by the fluid, while the confined catalytic ceramic membrane can still directly contact the influent water first, thereby efficiently oxidizing and removing pollutants and exerting the confined catalytic effect. At the same time, during backwashing, the pressure is directly borne by the flat porous ceramic membrane support without affecting the confined catalytic ceramic membrane. The confined catalytic ceramic membrane nanoreactor of the present invention can ensure that the confined catalytic ceramic membrane is not easily broken during operation, thereby ensuring continuous, efficient and high-quality water treatment.

[0040] In some embodiments, the confined catalytic ceramic membrane assembly is circumferentially sealed and fixed to the central region of the reaction chamber by sealant, and the upper shell and the lower shell are fixed by sealant; the inclination angle of the inclined region is ≤45°; preferably, both the upper shell and the lower shell are funnel-shaped, the funnel neck of the upper shell serves as the water inlet, and the funnel neck of the lower shell serves as the water outlet.

[0041] The dual-channel porous alumina membrane used in the confined catalytic ceramic membrane nanoreactor of this invention has highly regular, uniform, and adjustable pores, which can provide a uniform and precise nano-confined space to enhance the mass transfer of free radicals and the transfer of reaction electrons, maximizing the utilization of the confinement effect. At the same time, the vertically elongated pores of the confined catalytic ceramic membrane allow water to flow through the membrane layer with low resistance, achieving high membrane flux. Furthermore, loading a catalyst within the pores can improve the reaction kinetics and new pollutant removal rate in heterogeneous advanced oxidation processes. Combining the confined catalytic ceramic membrane with a flat porous ceramic membrane support can greatly improve the strength and stability of the confined catalytic ceramic membrane, solving the problem of easy breakage of the confined catalytic ceramic membrane.

[0042] The confined catalytic ceramic membrane nanoreactor of this invention can be used for the efficient removal of pollutants, especially new pollutants, from water by coupling advanced oxidation processes. Specifically, the confined catalytic ceramic membrane nanoreactor, when used in conjunction with oxidants such as hydrogen peroxide, ozone, and persulfate, constructs an integrated system of advanced oxidation and confined catalytic ceramic membrane filtration. This system efficiently oxidizes and degrades conventional organic pollutants and new pollutants while separating them through membrane filtration, achieving efficient purification of various types of water and wastewater, including drinking water, municipal sewage, and medical wastewater. Preferably, the highly catalytically active metal oxide catalyst loaded in the confined catalytic ceramic membrane can more efficiently activate oxidants such as hydrogen peroxide, ozone, and persulfate to generate reactive oxygen species such as hydroxyl radicals, singlet oxygen, or superoxide radicals, thereby enhancing the removal of pollutants (especially new pollutants) from water. The confined catalytic ceramic membrane nanoreactor of the present invention has a uniformly distributed and tunably sized nanoscale confinement space. Based on the scale dependence theory of confinement effect, it can maximize the utilization of confinement effect, shorten the mass transfer distance between reactive oxygen species and target pollutants during the reaction process, enhance the mass transfer of free radicals and reactants and the transfer of reaction electrons, strengthen the confined catalytic effect, and is not easily broken during water treatment, thus ensuring continuous, efficient and high-quality water treatment.

[0043] In some water treatment examples, the following steps are included:

[0044] S1. A confined catalytic ceramic membrane nanoreactor is used to continuously filter the water to be treated using a constant flux dead-end filtration method; preferably, the membrane flux is 20-100 L / (m²). 2 ·h);

[0045] S2. During membrane filtration, an oxidant is added to the confined catalytic ceramic membrane nanoreactor to initiate an advanced oxidation reaction catalyzed by the confined catalytic ceramic membrane, thereby enhancing the removal of new pollutants (especially new pollutants) in the water. Preferably, the oxidant is at least one of dissolved ozone, hydrogen peroxide, and persulfate. Preferably, the ozone dosage is 0.5-20 mg / L, and the hydrogen peroxide or persulfate dosage is 0.01-20 mM.

[0046] The new pollutants include, but are not limited to, at least one of the following common new pollutants found in natural water bodies: ofloxacin, ciprofloxacin, tiamulin, acetaminophen, salicylic acid, ibuprofen, erythromycin, tetracycline, oxytetracycline, roxithromycin, clarithromycin, and azithromycin.

[0047] In a specific embodiment of the present invention, the removal rate of new pollutants in water can exceed 99%.

[0048] The following describes specific embodiments of the present invention.

[0049] Example 1

[0050] like Figure 1As shown, the confined catalytic ceramic membrane nanoreactor includes a confined catalytic ceramic membrane 1, a flat porous ceramic membrane support 2, an upper shell 3, an inlet 4, a lower shell 5, and an outlet 6. The confined catalytic ceramic membrane 1 and the flat porous ceramic membrane support 2 constitute a confined catalytic ceramic membrane assembly. The upper shell 3 and the lower shell 5 are fixed to form a closed reaction chamber 7 (the reaction chamber 7 includes an inlet chamber 71 and an outlet chamber 72). The inlet 4 is located on the upper shell 3 and above the confined catalytic ceramic membrane 1 (i.e., the confined catalytic ceramic membrane 1 faces the inlet 4). The outlet 6 is located on the lower shell 5 and below the flat porous ceramic membrane support 2 (i.e., the flat porous ceramic membrane support 2 faces the outlet 6). The confined catalytic ceramic membrane 1 includes a dual-channel porous alumina membrane and a catalyst. The catalyst is loaded in the pores and on the surface of the dual-channel porous alumina membrane. The circumferential direction of the confined catalytic ceramic membrane 1 is fixed to the circumferential direction of the flat porous ceramic membrane support 2 with sealant 8 and fixed in the central region of the reaction chamber 7. The inner wall of the upper shell 3 has an oblique region 31 that gradually narrows from the confined catalytic ceramic membrane 1 to the inlet 4. In this example, both the upper shell 3 and the lower shell 5 are funnel-shaped. The funnel neck of the upper shell 3 serves as the inlet 4, and the funnel neck of the lower shell 5 serves as the outlet 6. The bottom (larger side) of the upper shell 3 and the top (larger side) of the lower shell 5 are fixed with sealant when assembled and fixed to the confined catalytic ceramic membrane assembly. Therefore, the inlet cavity 71 between the confined catalytic ceramic membrane 1 and the inlet 4 expands from the inlet 4 to the confined catalytic ceramic membrane 1, while the outlet cavity 72 between the flat porous ceramic membrane support 2 and the outlet 6 narrows from the flat porous ceramic membrane support 2 to the outlet 6.

[0051] The preparation method of the confined catalytic ceramic membrane nanoreactor in this embodiment includes the following steps:

[0052] (1) Cut commercially available double-pass porous alumina membranes with a pore size of less than 20 nm to the required size, ultrasonically clean them in ultrapure water for 3 min, and then dry them at 60-80℃ for 5-10 h for later use.

[0053] (2) Dissolve 0.15M manganese acetate (II) in a solvent mixture containing 15 mL methanol and 5 mL acetonitrile, and sonicate for 10 min to prepare a catalyst precursor solution.

[0054] (3) Immerse the double-pass porous alumina membrane obtained in step (1) into the catalyst precursor solution obtained in step (2) and place it on a shaker and shake continuously for 20 hours so that the catalyst precursor is fully adsorbed onto the membrane surface and pores of the double-pass porous alumina membrane.

[0055] (4) Step 3: The mixture was transferred into a polytetrafluoroethylene liner and sealed in a hydrothermal reactor. It was reacted at 180°C for 4 hours at a rate of 5°C / min, and then naturally cooled to room temperature.

[0056] (5) The catalyst-loaded double-channel porous alumina membrane obtained in step (4) is washed three times with ethanol and deionized water and then dried to obtain a confined catalytic ceramic membrane.

[0057] (6) Fix the confined catalytic ceramic membrane obtained in step (5) and the flat porous ceramic membrane support in the circumferential direction with sealant 8 and control the gap between the confined catalytic ceramic membrane and the flat porous ceramic membrane support to be less than 1 mm. Then fix it together with the upper shell and the lower shell with sealant to form a confined catalytic ceramic membrane nanoreactor.

[0058] like Figure 2a and 2b As shown, the scanning electron microscope (SEM) image of the confined catalytic ceramic membrane reveals that the catalyst is uniformly distributed within the pores of the membrane. In this example, the diameter of the dual-channel porous alumina membrane used is 25 mm. The prepared confined catalytic ceramic membrane has long, straight nanopores perpendicular to the membrane direction, with a pore size of 20-30 nm. The pores are short-range ordered and parallel to each other. The Mn3O4 nanoparticles grown in the pores of the dual-channel porous alumina membrane have a diameter of approximately 15-17 nm. In this example, the average pore size of the confined catalytic ceramic membrane is approximately 3-5 nm.

[0059] Example 2

[0060] Water treatment was carried out using the confined catalytic ceramic membrane nanoreactor provided in Example 1, such as... Figure 3 As shown, a continuous membrane filtration experiment was conducted using dead-end filtration to treat water containing 200 μg / L ibuprofen. Ozone was provided by an ozone stock solution. By analyzing the residence time and the concentration of pollutants degraded, the first-order degradation kinetic constant of ibuprofen was found to be as high as 0.035 s⁻¹. -1 It can remove more than 99% of ibuprofen in a residence time of less than 130 seconds, which confirms that the confined catalytic ceramic membrane has a strong confined catalytic effect.

[0061] The confined catalytic ceramic membrane of this invention exhibits high reaction kinetics and novel pollutant removal rates in heterogeneous advanced oxidation processes. By combining the confined catalytic ceramic membrane with a flat porous ceramic membrane support in a specific manner, the strength and stability of the confined catalytic ceramic membrane can be significantly improved, solving the problem of its susceptibility to breakage. The confined catalytic ceramic membrane nanoreactor of this invention can be widely used in various water treatment processes, including drinking water and medical wastewater treatment, to stably and efficiently remove various novel pollutants from water bodies.

[0062] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A confined catalytic ceramic membrane module, characterized in that, The device includes a confined catalytic ceramic membrane and a flat porous ceramic membrane support. The confined catalytic ceramic membrane is stacked on the flat porous ceramic membrane support, and the circumferential direction of the confined catalytic ceramic membrane is sealed and fixed to the circumferential direction of the flat porous ceramic membrane support. After fixing, the gap between the confined catalytic ceramic membrane and the flat porous ceramic membrane support is less than 1 mm. The unfixed areas of both allow water to flow through with low resistance. The confined catalytic ceramic membrane includes a dual-channel porous alumina membrane and a catalyst. The dual-channel porous alumina membrane has long, straight nanopores along the vertical direction of the membrane, with short-range ordered pore distribution and independent pores. The catalyst is loaded in the pores and on the surface of the dual-channel porous alumina membrane.

2. The confined catalytic ceramic membrane module as described in claim 1, characterized in that, The confined catalytic ceramic membrane is circumferentially bonded and sealed to the circumferentially of the flat porous ceramic membrane support by a sealant.

3. The confined catalytic ceramic membrane module as described in claim 1, characterized in that, The thickness of the dual-channel porous alumina film is 10-100 μm, and the pores on the dual-channel porous alumina film that are perpendicular to the film surface and uniformly distributed have a diameter of 10-100 nm and a pore spacing of 10-100 nm.

4. The confined catalytic ceramic membrane module as described in claim 1, characterized in that, The catalyst is a mono- or multi-component transition metal oxide with high catalytic activity, and the catalyst loading in the confined catalytic ceramic membrane is 0.5 wt%-5 wt%; the particle size of the catalyst is 5-20 nm.

5. The confined catalytic ceramic membrane module as described in claim 4, characterized in that, The mono-transition metal oxide is at least one of MnO, CuO, FeO, ZnO, and TiO; the multi-transition metal oxide is at least one of CuMnO, FeMnO, TiMnO, ZnMnO, CuFeMnO, CuZnMnO, CuTiMnO, and TiMnFeO.

6. The confined catalytic ceramic membrane module as described in claim 1, characterized in that, The thickness of the flat porous ceramic membrane support is 1-2 mm, and the average pore size is 1-3 μm; the material of the flat porous ceramic membrane support is aluminum oxide, or a mixture of aluminum oxide and silicon dioxide.

7. A method for preparing a confined catalytic ceramic membrane module according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Clean the double-pass porous alumina membrane with pores perpendicular to the membrane surface and evenly distributed, and set it aside for later use. S2. Prepare catalyst precursor solution. Immerse the double-pass porous alumina membrane from step S1 into the catalyst precursor solution so that the catalyst precursor solution is fully adsorbed onto the surface and pores of the double-pass porous alumina membrane. Then, treat it by hydrothermal method to obtain a confined catalytic ceramic membrane, clean and dry it for later use. S3. The confined catalytic ceramic membrane obtained in step S2 is sealed and fixed to the flat porous ceramic membrane support in the circumferential direction.

8. The preparation method according to claim 7, characterized in that, The fixing mentioned in step S3 refers to bonding with sealant.

9. The preparation method according to claim 7, characterized in that, In step S2: The precursor solution comprises 1 wt%-5 wt% of a catalyst precursor and 95 wt%-99 wt% of an organic solvent; the catalyst precursor is at least one selected from manganese nitrate, ferric nitrate, cobalt nitrate, copper nitrate, titanium nitrate, manganese sulfate, ferric sulfate, cobalt sulfate, copper sulfate, and titanium sulfate; the organic solvent is at least one selected from methanol, acetonitrile, ethanol, and ethylene glycol. The adsorption refers to: immersing the dual-channel porous alumina membrane in the catalyst precursor solution at room temperature and shaking it continuously on a shaker for 1-20 h, or immersing the dual-channel porous alumina membrane in the catalyst precursor solution at room temperature and treating it under ultrasound for 1-60 min, so that the catalyst precursor is loaded onto the surface and pores of the dual-channel porous alumina membrane. The hydrothermal process is as follows: the temperature is increased to 100-200℃ at a heating rate of 1-5℃ / min and reacted for 3-5 hours.

10. A confined catalytic ceramic membrane nanoreactor, characterized in that, The device includes a confined catalytic ceramic membrane assembly as described in any one of claims 1-6, an upper shell, an inlet, a lower shell, and an outlet; the upper shell and the lower shell are fixed to form a sealed reaction chamber, the confined catalytic ceramic membrane assembly is fixed in the central region of the reaction chamber, the inlet is located on the upper shell and above the confined catalytic ceramic membrane in the confined catalytic ceramic membrane assembly, and the outlet is located on the lower shell and below the flat porous ceramic membrane support in the confined catalytic ceramic membrane assembly; the inner wall of the upper shell has an oblique region that gradually narrows from the confined catalytic ceramic membrane to the inlet.

11. The confined catalytic ceramic membrane nanoreactor as described in claim 10, characterized in that, The confined catalytic ceramic membrane assembly is circumferentially sealed and fixed in the central region of the reaction chamber by sealant, and the upper shell and the lower shell are fixed by sealant; the inclination angle of the inclined region is ≤45°; both the upper shell and the lower shell are funnel-shaped, the funnel neck of the upper shell serves as the water inlet, and the funnel neck of the lower shell serves as the water outlet.

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