Confined-range catalytic ceramic membrane assembly, preparation method thereof and confined-range catalytic ceramic membrane nanoreactor

Abstract

The invention discloses a confined catalytic ceramic membrane assembly, a preparation method thereof and a confined catalytic ceramic membrane nano reactor. The confinement catalytic ceramic membrane assembly comprises a confinement catalytic ceramic membrane and a flat porous ceramic membrane support body, the confinement catalytic ceramic membrane is stacked on the flat porous ceramic membrane support body, and the circumferential direction of the confinement catalytic ceramic membrane and the circumferential direction of the flat porous ceramic membrane support body are sealed and fixed; the confinement catalytic ceramic membrane comprises a bi-pass porous alumina membrane and a catalyst, and the catalyst is loaded in pores and on the surface of the bi-pass porous alumina membrane. The confined catalytic ceramic membrane nanoreactor comprises the confined catalytic ceramic membrane assembly, the strength and stability of the confined catalytic ceramic membrane can be improved, the problem that an aluminum oxide membrane is prone to breakage in practical application is solved, and the confined catalytic ceramic membrane nanoreactor can stably and efficiently catalyze an advanced oxidation reaction in water treatment to remove multiple new pollutants in water.

Description

Technical Field

[0001] The present invention relates to the field of novel membrane filtration technology, and in particular to a confined catalytic ceramic membrane assembly and a preparation method thereof, and a confined catalytic ceramic membrane nanoreactor. Background Art

[0002] Due to the potential adverse effects of new 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 new pollutants during water treatment. However, traditional wastewater treatment methods are difficult to effectively remove these trace amounts of new pollutants. Treatment methods based on advanced oxidation processes can produce a variety of strong oxidizing active oxygen species, effectively remove new pollutants in water, and become a new pollutant control technology with great application prospects in the new water treatment era. However, traditional advanced oxidation processes have many technical bottlenecks that need to be overcome, such as high oxidant dosage in homogeneous systems, low utilization of active oxygen species, poor oxidation selectivity, easy catalyst agglomeration, and difficulty 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 enhanced 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-stacked state. These membranes suffer from shortcomings such as poor pore uniformity, small confined space volume, easy membrane rupture, low catalytic efficiency, catalytic stability, and low flux, which urgently need to be overcome, making it difficult to fully utilize the advantages of the confinement effect.

[0004] It should be noted that the information disclosed in the above background technology section is only used to understand the background of this application, and therefore may include information that does not constitute prior art known to ordinary technicians in this field. Summary of the Invention

[0005] In order to make up for the deficiencies of the prior art, the present invention provides a confined catalytic ceramic membrane assembly and a preparation method thereof, and a confined catalytic ceramic membrane nanoreactor.

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

[0007] In a first aspect, a confined catalytic ceramic membrane assembly is provided, which includes a confined catalytic ceramic membrane and a flat porous ceramic membrane support body, the confined catalytic ceramic membrane is stacked on the flat porous ceramic membrane support body, and the circumference of the confined catalytic ceramic membrane is sealed and fixed to the circumference of the flat porous ceramic membrane support body, the confined catalytic ceramic membrane includes a double-pass porous alumina membrane and a catalyst, and the catalyst is loaded in the pores and on the surface of the double-pass porous alumina membrane.

[0008] In a second aspect, a method for preparing the confined catalytic ceramic membrane assembly according to the first aspect is provided, comprising the following steps:

[0009] S1. Wash a double-pass porous alumina membrane having pores perpendicular to the membrane surface and evenly distributed for later use;

[0010] S2. Prepare a catalyst precursor solution, immerse the double-pass porous alumina membrane prepared in 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, and then treat it hydrothermally to obtain a confined catalytic ceramic membrane, which is then washed and dried for later use;

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

[0012] In the third aspect, a confined catalytic ceramic membrane nanoreactor is proposed, comprising the confined catalytic ceramic membrane assembly, an upper shell, a water inlet, a lower shell and a water outlet described in the first aspect; 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 middle area of the reaction chamber, the water inlet is located on the upper shell and above the confined catalytic ceramic membrane in the confined catalytic ceramic membrane assembly, and the water 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 area that gradually narrows from the confined catalytic ceramic membrane to the water inlet.

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

[0014] In the present invention, the double-pass porous alumina membrane used has highly regular, uniform and adjustable pores, which can provide uniform and precise nano-confined space to enhance the mass transfer of active oxygen species and the transfer of reaction electrons, and maximize the use of the confinement effect. At the same time, the vertical long straight pores of the confined catalytic ceramic membrane allow water to flow through the membrane layer at low resistance, achieving high membrane flux, loading catalysts on the surface and in the pores, and can improve the reaction rate and new pollutant removal rate in the heterogeneous advanced oxidation process. Combining the confined catalytic ceramic membrane of the present invention with a flat porous ceramic membrane support can greatly improve the strength and stability of the confined catalytic ceramic membrane, and solve the problem that the double-pass porous alumina membrane is easy to rupture. The confined catalytic ceramic membrane assembly and the confined catalytic ceramic membrane nanoreactor of the present invention can be widely used in various water treatments such as drinking water and medical wastewater, and can stably and efficiently remove a variety of new pollutants in water bodies.

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

[0016] (1) The confined catalytic ceramic membrane assembly and the confined catalytic ceramic membrane nanoreactor have the ability to maximize the use of the confinement effect. The confined catalytic ceramic membrane assembly and the confined catalytic ceramic membrane nanoreactor of the present invention are mainly prepared from a double-pass porous alumina membrane. The pore size of the confined catalytic ceramic membrane is uniform, the pore arrangement is short-range orderly, and the pores are independent, which provides an ideal confined space for confined catalytic reactions. Combined with the inherent pore size of the alumina membrane and controlling the catalyst loading parameters, the confinement scale of the confined catalytic ceramic membrane assembly and the confined catalytic ceramic membrane nanoreactor can be precisely regulated, thereby maximizing the use 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 flow through the membrane layer at low resistance, achieving a win-win situation in terms of flux and treatment effect.

[0017] (2) The confined catalytic ceramic membrane has strong catalytic stability. The catalyst confined in the pores of the double-pass porous alumina membrane has stronger catalytic stability and is not easily dissolved or detached.

[0018] (3) The confined catalytic ceramic membrane nanoreactor has good stability. A flat porous ceramic membrane with high mechanical strength and chemical stability is used as the support of the confined catalytic ceramic membrane. The two are sealed and fixed in the circumferential direction. The inner wall of the upper shell has an oblique area that gradually narrows from the confined catalytic ceramic membrane to the water inlet (that is, the water inlet chamber is in an expanded state from the water inlet to the confined catalytic ceramic membrane). Such an oblique water inlet chamber allows the water inlet chamber to evenly disperse the incoming water, reducing the physical impact of water on the surface of the confined catalytic ceramic membrane. Under dead-end filtration, the disadvantage that the confined catalytic ceramic membrane is easy to rupture is overcome. The confined catalytic ceramic membrane nanoreactor of the present invention can increase the operating pressure of the confined catalytic ceramic membrane to above -40kPa.

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

[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 not only ensure that no leakage occurs during filtration, but also prevent the membrane from rupturing due to over-tightening of the bolts in the traditional sealing method. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 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 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 membrane 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 the present invention. DETAILED DESCRIPTION

[0025] The following describes the embodiments of the present invention in detail. It should be emphasized that the following description is merely illustrative and is not intended to limit the scope and application of the present invention. The embodiments and features in the embodiments of this application may be combined with each other unless there is a conflict. In this article, "room temperature" refers to 20-25°C.

[0026] A specific embodiment of the present invention provides a confined catalytic ceramic membrane assembly, which includes a confined catalytic ceramic membrane and a flat porous ceramic membrane support body. The confined catalytic ceramic membrane is stacked on the flat porous ceramic membrane support body, and the circumference of the confined catalytic ceramic membrane is sealed and fixed to the circumference of the flat porous ceramic membrane support body. The confined catalytic ceramic membrane includes a double-pass porous alumina membrane and a catalyst. The catalyst is loaded in the pores and on the surface of the double-pass porous alumina membrane.

[0027] By fixing the confined catalytic ceramic membrane and the flat porous ceramic membrane support in the circumferential direction, after fixation, the gap between the confined catalytic ceramic membrane and the flat porous ceramic membrane support is less than 1 mm, and the unfixed area between the two allows water to flow through with low resistance. When the confined catalytic ceramic membrane assembly is applied to water treatment, it can ensure that the confined catalytic ceramic membrane is not easy to break and can better exert its catalytic efficiency.

[0028] In some embodiments, the circumference of the confined catalytic ceramic membrane and the circumference of the flat porous ceramic membrane support are sealed and fixed by bonding with a sealant.

[0029] In some embodiments, the thickness of the double-pass porous alumina membrane is 10-100 μm, the pore size of the pores perpendicular to the membrane surface and uniformly distributed on the double-pass porous alumina membrane is 10-100 nm (for example, the pore size is 10-20 nm, 20-30 nm, 40-70 nm, 80-100 nm, etc.), and the pore spacing is 10-100 nm.

[0030] In some embodiments, the catalyst is a mono- or multi-element transition metal oxide with high catalytic activity, and the loading amount of the catalyst 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-transition metal oxide is at least one of MnO, CuO, FeO, ZnO, and TiO; the multi-element transition metal oxide is at least one of CuMnO, FeMnO, TiMnO, ZnMnO, CuFeMnO, CuZnMnO, CuTiMnO, and TiMnFeO.

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

[0032] The specific embodiment of the present invention also provides a method for preparing a confined catalytic ceramic membrane assembly, comprising the following steps:

[0033] S1. Wash a double-pass porous alumina membrane having pores perpendicular to the membrane surface and evenly distributed 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 oxide), immerse the double-pass porous alumina membrane of 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, and then treat it by a hydrothermal method to obtain a confined catalytic ceramic membrane, which is washed and dried for standby use;

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

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

[0037] In some embodiments, in step S2: the precursor solution includes 1wt%-5wt% of a catalyst precursor and 95wt%-99wt% 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: at room temperature, immersing the double-pass porous alumina membrane in the catalyst precursor solution and continuously shaking it on a shaker for 1-20 hours, or at room temperature, immersing the double-pass porous alumina membrane in the catalyst precursor solution 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-pass porous alumina membrane; the hydrothermal method is: heating to 100-200°C at a heating rate of 1-5°C / min and reacting for 3-5 hours.

[0038] A specific embodiment of the present invention also provides a confined catalytic ceramic membrane nanoreactor, comprising the upper shell, water inlet, lower shell and water 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 middle area of the reaction chamber, the water inlet is located on the upper shell and above the confined catalytic ceramic membrane in the confined catalytic ceramic membrane assembly, and the water 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 area that gradually narrows from the confined catalytic ceramic membrane to the water inlet.

[0039] Double-pass porous alumina membrane has long straight nanopores along the vertical direction of the diaphragm, and the pore distribution is short-range and ordered, parallel to each other. This uniform and ordered nanopore structure feature is conducive to giving full play to the confinement effect, enhancing the mass transfer of free radicals and the transfer of reaction electrons, improving the treatment effect of new pollutants, and is beneficial to the improvement of membrane flux. However, the double-pass porous alumina membrane is very brittle and is easily broken when actually applied to a membrane reactor. To this end, the present invention designs the above-mentioned confined catalytic ceramic membrane nanoreactor. When filtering water, the flat porous ceramic membrane support can effectively carry and disperse the stress of the fluid on the confined catalytic ceramic membrane, and the confined catalytic ceramic membrane can still directly contact the water inlet 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 during its operation, the confined catalytic ceramic membrane is not easy to break, thereby ensuring the continuous, efficient and high-quality water treatment.

[0040] In some embodiments, the confined catalytic ceramic membrane assembly is fixed to the central area of the reaction chamber by circumferential sealing with sealant, and the upper shell and the lower shell are fixed by sealant; the inclination angle of the oblique area is ≤45°; preferably, the upper shell and the lower shell are both funnel-shaped, and 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 double-pass porous alumina membrane used in the confined catalytic ceramic membrane nanoreactor of the present invention has highly regular, uniform and adjustable pores, which can provide uniform and precise nano-confined space to enhance the mass transfer of free radicals and the transfer of reaction electrons, and maximize the use of the confinement effect. At the same time, the vertical long straight pores of the confined catalytic ceramic membrane allow water to flow through the membrane layer under low resistance, achieving high membrane flux. Further loading the catalyst in the pores can improve the reaction kinetics and new pollutant removal rate in the heterogeneous advanced oxidation process. 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, and solve the problem that the confined catalytic ceramic membrane is easy to rupture.

[0042] The confined catalytic ceramic membrane nanoreactor of the present invention can be used to efficiently remove pollutants in water, especially new pollutants, by coupling advanced oxidation treatment. Specifically, the confined catalytic ceramic membrane nanoreactor is used in conjunction with oxidants such as hydrogen peroxide, ozone, and persulfate to construct an integrated system of advanced oxidation and confined catalytic ceramic membrane filtration. While membrane filtration separates pollutants, it efficiently oxidizes and degrades conventional organic pollutants and new pollutants, thereby achieving efficient purification of various waters and sewage such as drinking water, urban domestic sewage, and medical waste water. Specifically preferably, the metal oxide catalyst with high catalytic activity loaded in the confined catalytic ceramic membrane can more efficiently activate oxidants such as hydrogen peroxide, ozone, and persulfate to produce reactive oxygen species such as hydroxyl radicals, singlet oxygen, or superoxide radicals, thereby enhancing the removal of pollutants (especially new pollutants) in water. The confined catalytic ceramic membrane in the confined catalytic ceramic membrane nanoreactor of the present invention has a uniformly distributed, uniformly sized and adjustable nano-confined space. It can maximize the utilization of the confinement effect based on the scale-dependence theory of the confinement effect, shorten the mass transfer distance between the active oxygen species and the 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 easy to break during the water treatment process, thereby ensuring continuous, efficient and high-quality treatment of water.

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

[0044] S1. Use confined catalytic ceramic membrane nanoreactor to continuously filter the water to be treated by constant flux dead-end filtration; preferably, the membrane flux is 20-100 L / (m 2 h);

[0045] S2. During the membrane filtration process, an oxidant is added to the confined catalytic ceramic membrane nanoreactor to initiate the advanced oxidation reaction catalyzed by the confined catalytic ceramic membrane and enhance 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 gas 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 the following new pollutants commonly found in natural water bodies: at least one of 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] Specific embodiments of the present invention are further described below.

[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, a water inlet 4, a lower shell 5 and a water 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 a water inlet chamber 71 and a water outlet chamber 72), the water inlet 4 is located on the upper shell 3 and above the confined catalytic ceramic membrane 1 (that is, the confined catalytic ceramic membrane 1 faces the water inlet 4), the water outlet 6 is located on the lower shell 5 and below the flat porous ceramic membrane support 2 (that is, the flat porous ceramic membrane support 2 faces the water outlet 6); the The confined catalytic ceramic membrane 1 includes a double-pass porous alumina membrane and a catalyst, and the catalyst is loaded in the pores and on the surface of the double-pass porous alumina membrane. The circumference of the confined catalytic ceramic membrane 1 and the circumference of the flat porous ceramic membrane support body 2 are fixed with sealant 8 and fixed to the middle area of the reaction chamber 7; the inner wall of the upper shell 3 has an oblique area 31 that gradually narrows from the confined catalytic ceramic membrane 1 to the water inlet 4. In this example, the upper shell 3 and the lower shell 5 are both funnel-shaped, the funnel neck of the upper shell 3 serves as the water inlet 4, and the funnel neck of the lower shell 5 serves as the water 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 water inlet cavity 71 between the confined catalytic ceramic membrane 1 and the water inlet 4 expands from the water inlet 4 to the confined catalytic ceramic membrane 1, and the water outlet cavity 72 between the flat porous ceramic membrane support 2 and the water outlet 6 narrows from the flat porous ceramic membrane support 2 to the water outlet 6.

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

[0052] (1) A commercial double-pass porous alumina membrane with a pore size of less than 20 nm was cut into the required size, ultrasonically cleaned in ultrapure water for 3 minutes, and then dried at 60-80°C for 5-10 hours for use.

[0053] (2) 0.15 M manganese (II) acetate was dissolved in a solvent mixture containing 15 mL of methanol and 5 mL of acetonitrile, and ultrasonically vibrated for 10 minutes 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 it continuously for 20 hours to allow the catalyst precursor to be fully adsorbed onto the membrane surface and pores of the double-pass porous alumina membrane.

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

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

[0057] (6) The confined catalytic ceramic membrane obtained in step (5) is fixed to the flat porous ceramic membrane support body with a sealant 8 in the circumferential direction and the gap between the confined catalytic ceramic membrane and the flat porous ceramic membrane support body is controlled to be less than 1 mm, and then fixed together with the upper shell and the lower shell with the sealant to form a confined catalytic ceramic membrane nanoreactor.

[0058] like Figure 2a and 2b As shown, a scanning electron microscope image of the confined catalytic ceramic membrane shows that the catalyst is evenly distributed in the pores of the confined catalytic ceramic membrane. The diameter of the double-pass porous alumina membrane used in this example is 25 mm. The prepared confined catalytic ceramic membrane has long straight nanopores with pore diameters of 20-30 nm along the vertical direction of the membrane. The pore distribution is short-range ordered and parallel to each other. The diameter of the Mn3O4 nanoparticles grown in the pores of the double-pass porous alumina membrane is approximately 15-17 nm. The average pore size of the confined catalytic ceramic membrane in this example is approximately 3-5 nm.

[0059] Example 2

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

[0061] The confined catalytic ceramic membrane of the present invention exhibits high reaction kinetics and new 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 membrane's strength and stability are significantly improved, addressing the membrane's susceptibility to rupture. The confined catalytic ceramic membrane nanoreactor of the present invention can be widely used in various water treatment processes, including drinking water and medical wastewater, to stably and efficiently remove a variety of new pollutants from water bodies.

[0062] The above description further details the present invention in conjunction with specific / preferred embodiments, and the specific implementation of the present invention should not be construed as being limited to these descriptions. Persons skilled in the art will appreciate that, without departing from the spirit of the present invention, they may make various substitutions or modifications to the described embodiments, and these substitutions or modifications should be considered to fall within the scope of protection of the present invention. Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "preferred embodiments," "examples," "specific examples," or "some examples" indicates that the specific features, structures, materials, or characteristics described in conjunction with such embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Persons skilled in the art may combine and assemble the different embodiments or examples described in this specification, as well as features of different embodiments or examples, without conflicting opinions. 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 may be made herein without departing from the scope of protection of the patent application.

Claims

1. A confined catalytic ceramic membrane assembly, characterized in that: It includes a confined catalytic ceramic membrane and a flat porous ceramic membrane support body, the confined catalytic ceramic membrane is stacked on the flat porous ceramic membrane support body, and the circumference of the confined catalytic ceramic membrane is sealed and fixed to the circumference of the flat porous ceramic membrane support body, the confined catalytic ceramic membrane includes a double-pass porous alumina membrane and a catalyst, and the catalyst is loaded in the pores and on the surface of the double-pass porous alumina membrane.

2. The confined catalytic ceramic membrane assembly according to claim 1, characterized in that: The circumference of the confined catalytic ceramic membrane and the circumference of the flat porous ceramic membrane support are sealed and fixed by bonding with sealant.

3. The confined catalytic ceramic membrane assembly according to claim 1, characterized in that: The thickness of the double-pass porous alumina membrane is 10-100 μm, the diameter of the pores on the double-pass porous alumina membrane that are perpendicular to the membrane surface and uniformly distributed is 10-100 nm, and the pore spacing is 10-100 nm.

4. The confined catalytic ceramic membrane assembly according to claim 1, characterized in that: The catalyst is a mono- or poly-transition metal oxide with high catalytic activity, and the loading amount of the catalyst in the confined catalytic ceramic membrane is 0.5wt%-5wt%; preferably, the particle size of the catalyst is 5-20nm; preferably, the mono-transition metal oxide is at least one of MnO, CuO, FeO, ZnO, and TiO; the poly-transition metal oxide is at least one of CuMnO, FeMnO, TiMnO, ZnMnO, CuFeMnO, CuZnMnO, CuTiMnO, and TiMnFeO.

5. The confined catalytic ceramic membrane assembly according to 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.

6. A method for preparing a confined catalytic ceramic membrane assembly according to any one of claims 1 to 5, characterized in that: The steps include: S1. Wash a double-pass porous alumina membrane having pores perpendicular to the membrane surface and evenly distributed for later use; S2. Prepare a catalyst precursor solution, immerse the double-pass porous alumina membrane prepared in 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, and then treat it hydrothermally to obtain a confined catalytic ceramic membrane, which is then washed and dried for later use; S3. The confined catalytic ceramic membrane prepared in step S2 is sealed and fixed to the flat porous ceramic membrane support in the circumferential direction.

7. The preparation method according to claim 6, wherein The fixing described in step S3 refers to bonding with a sealant.

8. The preparation method according to claim 6, wherein In step S2: The precursor solution comprises 1 wt% to 5 wt% of a catalyst precursor and 95 wt% to 99 wt% of an organic solvent; preferably, the catalyst precursor is at least one of manganese nitrate, iron nitrate, cobalt nitrate, copper nitrate, titanium nitrate, manganese sulfate, iron sulfate, cobalt sulfate, copper sulfate, and titanium sulfate; and the organic solvent is at least one of methanol, acetonitrile, ethanol, and ethylene glycol; The adsorption refers to: immersing the double-pass porous alumina membrane in the catalyst precursor solution and continuously shaking it on a shaker for 1-20 hours at room temperature, or immersing the double-pass porous alumina membrane in the catalyst precursor solution and treating it under ultrasound for 1-60 minutes at room temperature, so that the catalyst precursor is loaded on the surface and pores of the double-pass porous alumina membrane; The hydrothermal process is as follows: heating to 100-200° C. at a heating rate of 1-5° C. / min and reacting for 3-5 hours.

9. A confined catalytic ceramic membrane nanoreactor, characterized in that: It comprises the confined catalytic ceramic membrane assembly, upper shell, water inlet, lower shell and water outlet as described in any one of claims 1 to 5; 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 middle area of the reaction chamber, the water inlet is located on the upper shell and above the confined catalytic ceramic membrane in the confined catalytic ceramic membrane assembly, and the water 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 area that gradually narrows from the confined catalytic ceramic membrane to the water inlet.

10. The confined catalytic ceramic membrane nanoreactor according to claim 9, characterized in that: The confined catalytic ceramic membrane assembly is fixed to the central area of the reaction chamber by circumferential sealing with sealant, and the upper shell and the lower shell are fixed by sealant; the inclination angle of the oblique area is ≤45°; preferably, the upper shell and the lower shell are both 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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