Monolithic membrane material for purifying cosmetic emulsion wastewater and preparation method of monolithic membrane material

Abstract

The preparation method comprises the following steps: fixing a porous ceramic support body between an inlet and an outlet of a reactor, and putting the porous ceramic support body into a heating furnace; heating the reactor to a reaction temperature through a heating furnace under an inert protective atmosphere, then injecting a reaction liquid into the reactor to carry out a reaction for a period of time, and forming an airflow channel between an inlet and an outlet of the reactor; and cooling to room temperature after the reaction, taking out the porous ceramic support body, and stripping the carbon material attached to the outer surface of the porous ceramic support body to obtain the porous ceramic monolithic membrane material with the carbon material attached to the inner holes. According to the preparation method, the CNTs grow in the pore channels of the macroporous ceramic support body through an in-situ growth technology, so that the problems that the CNTs are easy to fall off and uneven in distribution and the like are effectively solved, the separation performance, the stability and the repeatability of the integral membrane material are improved, and a new solution is provided for efficient purification of cosmetic emulsion wastewater.

Description

Technical Field

[0001] The present invention relates to the technical field of membrane material separation, and particularly relates to an integral membrane material for purifying cosmetic emulsion wastewater and a preparation method thereof. Background Art

[0002] With the rapid development of the cosmetics industry, the discharge of cosmetic emulsion wastewater is increasing day by day. Its composition is complex, containing a large amount of refractory organic substances such as oils, surfactants, and fragrances, which are difficult to effectively remove by traditional treatment methods, causing serious environmental pollution. As an efficient and environmentally friendly water treatment technology, membrane separation technology shows great potential in the field of cosmetic emulsion wastewater treatment. However, traditional organic membrane materials have problems such as poor fouling resistance and short service life, while inorganic ceramic membrane materials face challenges such as high cost, low flux, and low separation accuracy.

[0003] Carbon nanotubes (CNTs) have received extensive attention in the field of membrane separation due to their unique structure and excellent properties. Introducing CNTs into membrane materials can effectively improve the separation performance of the membrane. However, existing technologies mostly use the post-loading method to modify CNTs on the membrane surface or fill them into the membrane pores. This method is suitable for the modification of organic supports or organic membrane materials, but there will be problems such as uneven distribution of carbon nanotubes and poor resistance to extreme conditions, resulting in unstable membrane performance, low membrane flux, and poor reusability. To address the above problems, some scholars have in-situ grown carbon nanotubes on ceramic supports to construct oil-water separation membranes: Dong Yingchao et al. [Journal of Membrane Science. 2019, 582: 140 - 150] grew carbon nanotubes on a mullite ceramic tube support with a pore size of 1 μm by chemical vapor deposition method, and prepared a composite membrane with an oil-water separation efficiency of 100% and a permeability of 6.5 L·m -2 ·h -1 ·bar -1 However, the binding force between the carbon nanotubes and the support is poor; in addition, Professor Teychene et al. [Separation and Purification Technology. 2021, 278: 119566] used a silicon carbide wafer with a membrane layer pore size of 0.1 μm and a support pore size of about 1.5 μm as a carrier to grow carbon nanotubes for oil-water separation, and the purification effect was good, but the electron microscopy results showed uneven growth of carbon nanotubes. Therefore, how to construct uniform and non-falling carbon nanotubes on a porous ceramic support is a technical problem that urgently needs to be solved. Summary of the Invention

[0004] The purpose of the present invention is to provide an integral membrane material for purifying cosmetic emulsion wastewater and a preparation method thereof to solve the above technical problems.

[0005] To achieve the above object, the technical solution provided by the present invention is as follows:

[0006] The first aspect of the present application provides a preparation method of an integrated membrane material for purifying cosmetic emulsion wastewater, comprising the following steps:

[0007] S1: Fix the porous ceramic support and place it in a closable reactor. One end of the reactor has an inlet and the other end has an outlet. The porous ceramic support is fixed between the inlet and the outlet of the reactor; close the reactor and confirm its airtightness except for the inlet and the outlet, and then place it in a heating furnace;

[0008] S2: Prepare the reaction solution, load the reaction solution into the liquid injection device, and connect the liquid injection device to the inlet of the reactor;

[0009] S3: Under an inert protective atmosphere, heat the reactor through the heating furnace to reach the reaction temperature, and then inject the reaction solution into the reactor through the liquid injection device for a period of reaction. After the reaction, cool it to room temperature; wherein, after the liquid injection device injects the reaction solution, it is removed from the inlet of the reactor, so that an air flow channel is formed between the inlet and the outlet of the reactor during the reaction process;

[0010] S4: Open the reactor, take out the porous ceramic support, and peel off the carbon material attached to its outer surface to obtain a porous ceramic integrated membrane material with carbon material attached to the inner pores.

[0011] To optimize the above technical solution, the specific measures taken also include:

[0012] The porous ceramic support is selected from silicon carbide, alumina or zirconia materials, with a porosity > 30% and a mechanical strength > 15 MPa.

[0013] Further, the thickness of the porous ceramic support is 2 - 5 mm, and the porous pore diameter is 15 - 50 μm.

[0014] The reaction solution is a ferrocene ethanol solution of 5 - 15 mg / ml; the rate of injecting the reaction solution into the reactor through the liquid injection device is 0.5 - 2 ml / min.

[0015] The reaction temperature is 600 - 700 °C; the reaction time is 3.5 - 4.5 h.

[0016] Further, the reactor includes a left part with an inlet and a right part with an outlet. The left part and the right part are an assemblable concave-convex fitting structure.

[0017] Fix the outer sidewall of the porous ceramic support through a graphite ring. By squeezing the graphite ring against the inner sidewall of the reaction chamber of the reactor, the porous ceramic support is made to stand in the reactor, and an air flow channel passing through the porous ceramic support is formed between the inlet and the outlet of the reactor.

[0018] Furthermore, the method for peeling off the carbon material attached to the outer surface of the support is to use tape to stick and peel off the carbon material attached to its outer surface.

[0019] The second aspect of the present application provides an integral membrane material for purifying cosmetic emulsion wastewater, which is prepared by the above method.

[0020] The porous ceramic integral membrane material described above has carbon nanotube-modified support pores and can be used for the oil-water separation of cosmetic emulsion wastewater.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The present invention prepares a porous ceramic integral membrane material for purifying cosmetic emulsion wastewater. By means of in-situ growth technology, CNTs (carbon nanotubes) are grown in the pores of the macroporous ceramic support. The carbon nanotubes are intertwined and firmly confined in the support pores and are difficult to be purged by the backwashing water flow, effectively solving the problems such as easy shedding and uneven distribution of carbon nanotubes, improving the separation performance, stability and repeatability of the integral membrane material, and providing a new solution for the efficient purification of cosmetic emulsion wastewater.

[0023] The present invention constructs uniform and non-falling carbon nanotubes on the porous ceramic support. Compared with the carbon nanotubes with poor bonding force grown on the surface of the ceramic carrier in the prior art, the carbon nanotubes in the pores of the present invention are more firmly fixed and will not fall off under water flow scouring, and it can be seen from the electron microscope photos that they are uniformly grown. By modifying the support pores with carbon nanotubes, the present invention can realize the preparation of membrane materials with different pore sizes; the carbon nanotubes are in-situ grown and intertwined in the pores and are confined in the tortuous pore structure of the ceramic support, which can avoid falling off during oil-water separation; and the good thermal stability of the carbon nanotubes is beneficial to the performance recovery of the membrane material, enabling the material to maintain good practical performance.

[0024] Based on an in - depth analysis of the laws of process changes such as crystal nucleation and crystal plane activity of catalyst particles (ferrocene), as well as the decomposition process of carbon precursors and the mechanism of dissolution, diffusion, and rearrangement of carbon atoms on catalyst particles, the optimal reaction scheme of the present invention was finally obtained after multiple theoretical calculations and experimental optimizations. Through the comprehensive application of knowledge based on confinement effects, theoretical calculations, reaction kinetics, environmental variable control, device and instrument structure design, fluidics, etc., the present invention has obtained an air - induced chemical vapor deposition technology for the preparation of porous ceramic monolithic membrane materials for oil - water separation of cosmetic emulsion wastewater, and has revealed the mass transfer mechanism of reaction materials in micron - scale non - straight channels through the action law of confinement effects on the growth of carbon nanotubes.

[0025] The process of the present invention is simple and pollution - free. The synthetic raw materials used are ethanol and ferrocene, which have great economic advantages in industrial production.

[0026] The technology of the present invention can realize the controllable preparation of a monolithic membrane material with carbon nanotubes modified ceramic pores for high - temperature regeneration, providing a technical reference for the development of oil - water separation membranes. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structural relationship setting of the reactor, graphite ring, and porous ceramic support in the preparation method of the present invention.

[0028] Figure 2 It is an electron micrograph of the monolithic membrane material prepared in Example 1: (a) Electron micrograph of the surface of the membrane material, (b) Electron micrograph of carbon nanotubes in the porous ceramic support.

[0029] Figure 3 It is the surface roughness of the porous ceramic support and the porous ceramic monolithic membrane material in Example 1: (a) Porous ceramic support, (b) Porous ceramic monolithic membrane material.

[0030] Figure 4 It is a parameter diagram of the porous ceramic monolithic membrane material prepared in Example 1: (a) Pore size distribution diagram and (b) Pure water flux.

[0031] Figure 5 It is the separation result of the porous ceramic monolithic membrane material prepared in Example 1 for an oil - water emulsion with a concentration of 500 ppm: (a) Flux change and filtration efficiency of the membrane material, (b) Photos of the initial emulsion and the filtrate after separation. DETAILED DESCRIPTION OF THE INVENTION

[0032] The above content of the present invention will be further described in detail below in the form of specific embodiments. However, it should not be understood that the scope of the above - mentioned subject matter of the present invention is limited to the following embodiments. All technologies implemented based on the above content of the present invention belong to the scope of the present invention.

[0033] The experimental methods used in the following examples are all conventional methods unless otherwise specified, and the reagents, methods, and equipment used are all conventional reagents, methods, and equipment in the technical field unless otherwise specified.

[0034] For the sake of brevity, only some numerical values and optional ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form a range not explicitly recited; and any lower limit can be combined with other lower limits to form a range not explicitly recited, and similarly any upper limit can be combined with any other upper limit to form a range not explicitly recited; the options within the optional range can also be combined arbitrarily.

[0035] The present invention provides a preparation method of an integral membrane material for purifying cosmetic emulsion wastewater, comprising the following steps:

[0036] (1): Fix the porous ceramic support and place it in a closable reactor. As Figure 1 shown, one end of the reactor has an inlet and the other end has an outlet, and the porous ceramic support is fixed between the inlet and the outlet of the reactor; close the reactor and confirm its airtightness except for the inlet and the outlet, and then place it in a heating furnace;

[0037] (2): Prepare the reaction solution, load the reaction solution into the liquid injection device, and connect the liquid injection device to the inlet of the reactor;

[0038] (3): Under an inert protective atmosphere, heat the reactor to the reaction temperature through the heating furnace, and then inject the reaction solution into the reactor through the liquid injection device for a period of reaction, and cool to room temperature after the reaction; wherein, after the liquid injection device injects the reaction solution, it is removed from the inlet of the reactor, so that an air flow channel is formed between the inlet and the outlet of the reactor during the reaction;

[0039] (4): Open the reactor, take out the porous ceramic support, and peel off the carbon material attached to its outer surface to obtain a porous ceramic integral membrane material with carbon material attached to the inner pores.

[0040] In some embodiments, the porous ceramic support is selected from silicon carbide, alumina or zirconia materials, the porosity > 30%, and the mechanical strength > 15 MPa.

[0041] In some embodiments, the thickness of the porous ceramic support is 2 - 5 mm, and the pore size is 15 - 50 μm.

[0042] In some embodiments, the reaction solution is a ferrocene ethanol solution of 5 - 15 mg / ml; the rate of injecting the reaction solution into the reactor through the liquid injection device is 0.5 - 2 ml / min.

[0043] In some embodiments, the reaction temperature is 600 - 700 °C; the reaction time is 3.5 - 4.5 h.

[0044] In some embodiments, the reactor includes a left part with an inlet and a right part with an outlet, and the left part and the right part are an assemblable concave-convex fitting structure.

[0045] In some embodiments, the outer sidewall of the porous ceramic support is fixed by a graphite ring. The porous ceramic support stands in the reactor by the extrusion of the graphite ring on the inner sidewall of the reaction chamber of the reactor, and an air flow channel passing through the porous ceramic support is formed between the inlet and the outlet of the reactor.

[0046] In some embodiments, the method for peeling off the carbon material attached to the outer surface of the support is to stick and peel off the carbon material attached to its outer surface with tape.

[0047] The following uses non-limiting examples to illustrate the size of the porous ceramic support fixed by the graphite ring, the size of the reactor, and the dosage of the reaction solution:

[0048] The porous ceramic support is a porous ceramic sheet, the thickness of the porous ceramic sheet is 2 - 5 mm, and the outer diameter of the porous ceramic sheet is 20 - 60 mm;

[0049] The graphite ring for fixing the porous ceramic support is one or two. The two graphite ring are respectively corresponding to both sides of the porous ceramic support; the wall thickness of the graphite ring is 2 - 10 mm. The inner diameter of the graphite ring can be the same as or slightly smaller than the outer diameter of the porous ceramic sheet, and a setting can be adopted such that the outer diameter of the graphite ring can be the same as the outer diameter of the porous ceramic sheet;

[0050] The diameter of the reaction chamber of the reactor matches the sizes of the graphite ring and the porous ceramic sheet, so that the graphite ring fixed with the porous ceramic support can make the porous ceramic support stand in the reactor by extruding the inner sidewall of the reaction chamber;

[0051] The dosage of the reaction solution is related to the size of the porous ceramic support and the size of the porous aperture. The larger the porous ceramic support and the larger the porous aperture, the more the dosage of the reaction solution. For example: when the diameter of the porous ceramic sheet is 30 mm, if the porous aperture is 15 - 25 μm, the dosage of the reaction solution is 60 ml; if the porous aperture is 26 - 35 μm, the dosage of the reaction solution is 70 ml; if the aperture is 36 - 50 μm, the dosage of the reaction solution is 80 ml.

[0052] The inert protective atmosphere during the reaction can specifically be nitrogen or argon with an air flow rate of 40 - 70 ml / min.

[0053] The second aspect of the present application provides an integral membrane material for purifying cosmetic emulsion wastewater, which is prepared by the above method.

[0054] The porous ceramic monolithic membrane material has carbon nanotube-modified support pores and can be used for the oil-water separation of cosmetic emulsion wastewater.

[0055] The technical solution of the present invention will be further described in detail with reference to specific embodiments as follows:

[0056] Example 1

[0057] Place a porous silicon carbide support with a porosity of 38%, a pore diameter of 45 μm, a mechanical strength of 18 MPa, a thickness of 3 mm, and a diameter of 30 mm between two graphite ring washers with a wall thickness of 2 mm, a height of 3 mm, and an outer diameter of 30 mm. Then, put them together into a reactor with an uneven fitting structure. After fixing the two parts of the reactor with screws, check the airtightness with soapy water to see if there is any air leakage at the connection of the reactor. After confirming no air leakage, place it into the furnace chamber of a tube furnace.

[0058] Prepare 80 ml of a ferrocene ethanol solution with a concentration of 10 mg / ml and pour it into a sample bottle. Connect it to the reactor inlet through a peristaltic pump for standby.

[0059] Introduce nitrogen into the reactor at a rate of 50 ml / min, and at the same time heat up the reaction furnace. When the temperature reaches 650 °C, start the peristaltic pump to let the mixed liquid enter the reactor at a feeding rate of 1 ml / min, and the reaction time is 4 h.

[0060] After the reaction is completed, let it cool naturally. Take out the ceramic support and repeatedly peel the carbon material on the surface of the support with transparent tape until no black substance remains after pressing with toilet paper, then the monolithic separation membrane material constructed with carbon nanotube-modified ceramic pores can be obtained.

[0061] The average pore diameter of the obtained membrane material is 1.0 μm, and the pure water flux is 265 L·m -2 ·h -1 ⁻²·h⁻¹. Under a transmembrane pressure difference of 1.5 bar, the separation efficiency for a 500 ppm water-in-oil emulsion is 99.99%.

[0062] Example 2

[0063] Place a porous silicon carbide support with a porosity of 32%, a pore diameter of 15 μm, a mechanical strength of 37 MPa, a thickness of 3 mm, and a diameter of 30 mm between two graphite ring washers with a wall thickness of 2 mm, a height of 3 mm, and an outer diameter of 30 mm. Then, put them together into a reactor with an uneven fitting structure. After fixing the two parts of the reactor with screws, check the airtightness with soapy water to see if there is any air leakage at the connection of the reactor. After confirming no air leakage, place it into the furnace chamber of a tube furnace.

[0064] Prepare 60 ml of a ferrocene ethanol solution with a concentration of 10 mg / ml and pour it into a sample bottle. Connect it to the reactor inlet through a peristaltic pump for standby.

[0065] Introduce nitrogen into the reactor at a rate of 50 ml / min, and at the same time heat up the reaction furnace; when the temperature reaches 650 °C, start the peristaltic pump to allow the mixed solution to reach the reactor at a feeding rate of 1 ml / min, and the reaction time is 4 h.

[0066] After the reaction is completed, let it cool naturally, take out the ceramic support, and repeatedly peel off the carbon material on the surface of the support with transparent tape until no black substance remains after pressing with toilet paper, then the monolithic separation membrane material constructed by carbon nanotube-modified ceramic pores can be obtained.

[0067] The average pore diameter of the obtained membrane material is 0.5 μm, and the pure water flux is 171 L·m -2 ·h -1 , and under a transmembrane pressure difference of 1.5 bar, the separation efficiency for 500 ppm water-in-oil emulsion is 100%.

[0068] Example 3

[0069] Place a porous silicon carbide support with a porosity of 42%, a pore diameter of 50 μm, a mechanical strength of 16 MPa, a thickness of 3 mm, and a diameter of 30 mm between two graphite ring rings with a wall thickness of 2 mm, a height of 3 mm, and an outer diameter of 30 mm. Then put them together into a reactor with an uneven fitting structure. After fixing the two parts of the reactor with screws, check the airtightness with soapy water to see if there is air leakage at the connection of the reactor. After confirming no air leakage, place it in the furnace chamber of a tube furnace.

[0070] Prepare 80 ml of a ferrocene ethanol solution with a concentration of 10 mg / ml and pour it into a sample bottle, and connect it to the reactor inlet through a peristaltic pump for standby.

[0071] Introduce nitrogen into the reactor at a rate of 50 ml / min, and at the same time heat up the reaction furnace; when the temperature reaches 650 °C, start the peristaltic pump to allow the mixed solution to reach the reactor at a feeding rate of 1 ml / min, and the reaction time is 4 h.

[0072] After the reaction is completed, let it cool naturally, take out the ceramic support, and repeatedly peel off the carbon material on the surface of the support with transparent tape until no black substance remains after pressing with toilet paper, then the monolithic separation membrane material constructed by carbon nanotube-modified ceramic pores can be obtained.

[0073] The average pore diameter of the obtained membrane material is 1.5 μm, and the pure water flux is 343 L·m -2 ·h -1 , and under a transmembrane pressure difference of 1.0 bar, the separation efficiency for 500 ppm water-in-oil emulsion is 98.58%.

[0074] Example 4

[0075] Place a porous zirconia support with a porosity of 35%, a pore size of 30 μm, a mechanical strength of 26 MPa, a thickness of 3 mm, and a diameter of 30 mm between two graphite ring annuli with a wall thickness of 2 mm, a height of 3 mm, and an outer diameter of 30 mm. Then, load them together into a reactor with a concave-convex fitting structure. After fixing the two parts of the reactor with screws, check the airtightness with soapy water to see if there is any air leakage at the reactor connection. After confirming no air leakage, place it into the furnace chamber of a tube furnace.

[0076] Prepare 70 ml of a ferrocene ethanol solution with a concentration of 10 mg / ml and pour it into a sample bottle. Connect it to the reactor inlet through a peristaltic pump for standby.

[0077] Pass nitrogen into the reactor at a rate of 50 ml / min while heating up the reaction furnace. When the temperature reaches 650 °C, start the peristaltic pump to allow the mixed solution to enter the reactor at a feeding rate of 1 ml / min for a reaction time of 4 h.

[0078] After the reaction is completed, let it cool naturally. Take out the ceramic support and repeatedly peel the carbon material on the surface of the support with transparent tape until no black substance remains after pressing with toilet paper, then an integral separation membrane material constructed by carbon nanotube-modified ceramic pores can be obtained.

[0079] The obtained membrane material has an average pore size of 0.8 μm and a pure water flux of 240 L·m -2 ·h -1 -1·h-1. Under a transmembrane pressure difference of 1.5 bar, the separation efficiency for a 500 ppm water-in-oil emulsion is 99.95%.

[0080] Example 5

[0081] Place a porous alumina support with a porosity of 38%, a pore size of 22 μm, a mechanical strength of 30 MPa, a thickness of 3 mm, and a diameter of 30 mm between two graphite ring annuli with a wall thickness of 2 mm, a height of 3 mm, and an outer diameter of 30 mm. Then, load them together into a reactor with a concave-convex fitting structure. After fixing the two parts of the reactor with screws, check the airtightness with soapy water to see if there is any air leakage at the reactor connection. After confirming no air leakage, place it into the furnace chamber of a tube furnace.

[0082] Prepare 60 ml of a ferrocene ethanol solution with a concentration of 10 mg / ml and pour it into a sample bottle. Connect it to the reactor inlet through a peristaltic pump for standby.

[0083] Pass nitrogen into the reactor at a rate of 50 ml / min while heating up the reaction furnace. When the temperature reaches 650 °C, start the peristaltic pump to allow the mixed solution to enter the reactor at a feeding rate of 1 ml / min for a reaction time of 4 h.

[0084] After the reaction is completed, it is naturally cooled, and the ceramic support is taken out. The carbon material on the surface of the support is repeatedly peeled off with transparent tape until no black substance remains after pressing with toilet paper, and then the monolithic separation membrane material constructed by carbon nanotube-modified ceramic pores can be obtained.

[0085] The average pore size of the obtained membrane material is 0.9 μm, and the pure water flux is 286 L·m -2 ·h -1 -1·h-1. Under a transmembrane pressure difference of 1.5 bar, the separation efficiency for a 500 ppm water-in-oil emulsion is 99.97%.

[0086] Comparative Example 1

[0087] This comparative example adopts the solution of Patent Publication No. CN107096393A (a thermally stable, superhydrophobic ceramic-carbon nanotube composite membrane and its application in membrane distillation water treatment).

[0088] The carrier used in this comparative example is a spinel hollow fiber ceramic membrane with a relatively small pore size (such as 1.7 μm). When the carbon source (methane) penetrates and diffuses into the pores of the ceramic particles during the CVD process, it faces greater resistance, resulting in difficulty in growing uniform and stable carbon nanotubes in the pores. The carbon nanotubes grow concentrated on the surface of the ceramic membrane. This solution still faces the key technical problem of carbon nanotube shedding during the separation process of oil-water emulsions.

[0089] On the other hand, the impregnation method is used for loading the nickel nitrate catalyst in this comparative example, and the growth of carbon nanotubes in the pores is not ideal. Through testing, when impregnating the carbon nanotube catalyst on a ceramic support with a pore size > 5 μm and growing carbon nanotubes under a reaction pressure of 1000 Pa, affected by the confinement effect, etc., the carbon nanotubes in the pores will damage the connection between ceramic particles during the growth process, resulting in damage to the support and ultimately failure in the preparation of the composite membrane. When impregnating the carbon nanotube catalyst in a ceramic support with a pore size of about 2 μm, the growth of carbon nanotubes in the pores is not ideal, and the growth of carbon nanotubes is less, making it difficult to effectively modify the support, resulting in no separation effect of the prepared catalytic membrane on the water emulsion.

[0090] Comparative Example 2

[0091] This comparative example adopts the solution of Patent Publication No. CN105289325A (a preparation method of a silver-loaded carbon nanotube ceramic composite membrane for air purification).

[0092] The carbon nanotube preparation technology used in this comparative example also involves ultrasonically mixing ferrocene and ethanol and then injecting them into the reactor. However, the treated ceramic membrane in this solution is placed in a quartz boat and then in a tubular furnace reactor. In this way, after ferrocene and ethanol enter the high-temperature reactor (quartz glass), they will migrate and naturally deposit along with the carrier gas flow;

[0093] Moreover, the alumina support used in this comparative example has a relatively small pore size (below 3.5 μm) and a pore structure of stacked pores. After repeated tests, under these experimental conditions, only a small amount of carbon nanotubes were found in the pores after peeling off the surface carbon nanotubes with transparent tape, and there was no ideal carbon nanotube modification as in the present invention.

[0094] Therefore, the silver-loaded carbon nanotubes prepared by this scheme do not have an ideal performance for cosmetic emulsion wastewater and cannot achieve the application effect of the present invention. The essential difference between the two lies in that the present invention regulates the generation process of carbon nanotube catalyst particles and the reaction kinetics of carbon atoms generated by the decomposition of carbon precursors by comprehensively considering three main factors: the reaction environment variables, the pore structure of the support, and the airflow directional induction, so as to generate a large number of carbon nanotubes in the pores of the ceramic support.

[0095] Comparative Example 3

[0096] This comparative example adopts the scheme (a method for preparing a carbon nanotube-based gas catalytic membrane with controllable morphology) with the patent publication number CN109967078A.

[0097] In this comparative example, since the main mass transfer paths of the catalyst particles and the carbon atoms generated by the decomposition of the carbon precursor are the macroscopic open space channels between the ceramic support and the reactor tube wall, the following problems all occur: the deposition of ferrocene and ethanol in the ceramic pores is affected by the resistance of the ceramic structure, and the deposition density on the surface of the ceramic membrane will be higher, resulting in a gradient deposition in the pores, which leads to a gradient growth of carbon nanotubes and affects the performance of the membrane material.

[0098] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention and based on the technical essence of the present invention, any simple modification, equivalent replacement, and improvement made to the above embodiments still fall within the protection scope of the technical solution of the present invention.

Claims

1. A preparation method of an integral membrane material for purifying cosmetic emulsion wastewater, characterized in that, It includes the following steps: S1: Fix the porous ceramic support and place it in a closable reactor. One end of the reactor has an inlet and the other end has an outlet. The porous ceramic support is fixed between the inlet and the outlet of the reactor; close the reactor and confirm its airtightness except for the inlet and the outlet, and then place it in a heating furnace; S2: Prepare the reaction solution, load the reaction solution into the liquid injection device, and connect the liquid injection device to the inlet of the reactor; S3: Under an inert protective atmosphere, heat the reactor to the reaction temperature through the heating of the heating furnace, and then inject the reaction solution into the reactor through the liquid injection device for a period of reaction, and cool it to room temperature after the reaction; wherein, after the liquid injection device injects the reaction solution, it is removed from the inlet of the reactor, so that an air flow channel is formed between the inlet and the outlet of the reactor during the reaction process; S4: Open the reactor, take out the porous ceramic support, and peel off the carbon material attached to its outer surface to obtain a porous ceramic monolithic membrane material with carbon material attached to the inner pores.

2. The preparation method of the monolithic membrane material for purifying cosmetic emulsion wastewater according to claim 1, characterized in that: The porous ceramic support is selected from silicon carbide, alumina or zirconia materials, with a porosity > 30% and a mechanical strength > 15 MPa.

3. The preparation method of the integral membrane material for purifying cosmetic emulsion wastewater according to claim 1, characterized in that: The thickness of the porous ceramic support is 2 - 5 mm, and the porous pore diameter is 15 - 50 μm.

4. The preparation method of the integral membrane material for purifying cosmetic emulsion wastewater according to claim 1, characterized in that: The reaction solution is a ferrocene ethanol solution with a concentration of 5 - 15 mg / ml; the rate of injecting the reaction solution into the reactor through the liquid injection device is 0.5 - 2 ml / min.

5. The preparation method of the monolithic membrane material for purifying cosmetic emulsion wastewater according to claim 1, characterized in that: The reaction temperature is 600 - 700 °C; the reaction time is 3.5 - 4.5 h.

6. The preparation method of the integral membrane material for purifying cosmetic emulsion wastewater according to claim 1, characterized in that: The reactor includes a left part with an inlet and a right part with an outlet. The left part and the right part are an assemblable concave-convex fitting structure.

7. The preparation method of the integral membrane material for purifying cosmetic emulsion wastewater according to claim 1, characterized in that: Fix the outer side wall of the porous ceramic support through a graphite ring, and make the porous ceramic support stand in the reactor by the extrusion of the graphite ring on the inner side wall of the reaction chamber of the reactor, and an air flow channel passing through the porous ceramic support is formed between the inlet and the outlet of the reactor.

8. The preparation method of the integral membrane material for purifying cosmetic emulsion wastewater according to claim 1, characterized in that: The method for peeling off the carbon material attached to the outer surface of the support is to use tape to stick and peel the carbon material attached to its outer surface.

9. An integral membrane material for purifying wastewater from cosmetic emulsions, characterized in that: It is prepared by the method described in any one of claims 1 - 9.

10. The monolithic membrane material for purifying cosmetic emulsion wastewater according to claim 9, characterized in that: The porous ceramic monolithic membrane material has carbon nanotube-modified support pores and can be used for the oil-water separation of cosmetic emulsion wastewater.

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