An integrated conductive ceramic membrane and a preparation method and application thereof

Abstract

The application provides an integrated conductive ceramic membrane and a preparation method and application thereof, and belongs to the technical field of sewage treatment. The application uses a Sn source and a metal dopant as raw materials, adopts a co-precipitation-calcination-mixing ball milling-hydraulic pressing-calcination method, makes the ceramic membrane have a conductive capacity, directly prepares the integrated conductive ceramic membrane, and realizes the preparation of the integrated conductive ceramic membrane. The method makes the whole ceramic membrane have the conductive property, can not only avoid the problem of falling off of the conductive coating existing in the coating method, but also can simplify the preparation process, reduce the generation difficulty, and improve the membrane preparation efficiency.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to an integrated conductive ceramic membrane, its preparation method, and its application. Background Technology

[0002] Current conductive ceramic membranes are primarily prepared using coating methods, including but not limited to: directly spraying conductive materials onto ordinary ceramic membranes, immersing ordinary ceramic membranes in a conductive material solution, and inserting conductive materials into the pores of ordinary ceramic membranes. However, coating methods are typically complex, requiring treatment of both the conductive material and the ordinary ceramic membrane, resulting in low membrane-making efficiency. Importantly, the conductive portion of conductive ceramic membranes prepared using coating methods is separate from the membrane itself, leading to the problem of conductive coating or material easily detaching. If conductive material detaches during wastewater treatment, it not only reduces treatment effectiveness but also significantly shortens membrane lifespan, resulting in poor reliability for these types of conductive ceramic membranes. Summary of the Invention

[0003] The purpose of this invention is to provide an integrated conductive ceramic film, its preparation method, and its application. The integrated conductive ceramic film is conductive as a whole, which not only avoids the problem of conductive coating peeling in the coating method, but also simplifies the preparation process and reduces the difficulty of production.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a method for preparing an integral conductive ceramic film, comprising the following steps:

[0006] A tin source, a metal dopant, an alkaline reagent, and an organic solvent are mixed to carry out a co-precipitation reaction to obtain a precipitated product.

[0007] The precipitated product was subjected to a first calcination to obtain conductive powder.

[0008] The conductive powder, additives, and alcohol solvent are mixed and ball-milled to obtain nano-conductive powder;

[0009] The nano-conductive powder is hydraulically pressed to obtain a tablet;

[0010] The compressed sheet is subjected to a second calcination to obtain an integral conductive ceramic film;

[0011] The metal dopant may contain Sb, Co, Ni, La, Mn, Al, or Zn.

[0012] Preferably, the tin source includes SnCl4 or SnCl2; the alkaline reagent includes ammonia.

[0013] Preferably, the metal dopant includes SbCl3, CoCl2, NiCl2, LaCl3, MnCl2, AlCl3, or ZnCl2; the molar amount of the metal element in the metal dopant is 0 to 12% of the Sn element in the tin source and is not 0.

[0014] Preferably, the pH of the coprecipitation reaction is 8.0–10; the temperature is 60–100°C; and the time is 2–6 hours.

[0015] Preferably, the temperature of the first calcination is 500-800℃ and the time is 1-4h.

[0016] Preferably, the additives include alumina, zirconium oxide, or silicon carbide; the mass of the additives is 0-60% of the mass of the conductive powder; the mixing and ball milling time is 1-3 hours; the hydraulic pressing pressure is 3-9 MPa, and the stabilization time is 40-80 seconds.

[0017] Preferably, the second calcination temperature is 900–1200°C and the time is 1–4 hours.

[0018] The present invention provides an integrated conductive ceramic membrane prepared by the preparation method described above, which is used for wastewater treatment using a cross-flow electrochemical coupling membrane separation device.

[0019] Preferably, the cross-flow electrochemical coupling membrane separation device includes a raw water tank 1, a diaphragm pump 2, a power supply 3, an electrolysis-filtration reactor 4, a product water tank 5, a reflux water regulating valve 8, and a product water regulating valve 9. The raw water tank 1, diaphragm pump 2, electrolysis-filtration reactor 4, and product water tank 5 are connected sequentially. The power supply 3 is connected to the electrolysis-filtration reactor 4. The electrolysis-filtration reactor 4 is equipped with a conductive ceramic membrane 6 and a cathode 7. The reflux water regulating valve 8 is installed in the pipeline between the electrolysis-filtration reactor 4 and the raw water tank 1, and the product water regulating valve 9 is installed in the pipeline between the electrolysis-filtration reactor 4 and the product water tank 5. The conductive ceramic membrane 6 is the integrated conductive ceramic membrane described in the above technical solution. The integrated conductive ceramic membrane serves as the anode.

[0020] This invention provides the application of the integrated conductive ceramic membrane described above in wastewater treatment.

[0021] This invention provides a method for preparing an integrated conductive ceramic membrane using a co-firing method. Using a Sn source and a metal dopant as raw materials, this invention employs a co-precipitation-calcination-mixing ball milling-hydraulic pressing-calcination process to directly prepare an "integrated" conductive ceramic membrane, thereby achieving the preparation of an integrated conductive ceramic membrane and simultaneously endowing the membrane with both conductivity and membrane separation efficiency. The term "integrated" in this invention distinguishes it from coating methods where the conductive material is independent of the ceramic membrane body. "Integrated" here refers to the close bonding of conductive powder materials to form the entire conductive ceramic membrane, rather than a loaded modified conductive layer. This method ensures that the entire ceramic membrane is conductive, avoiding the problem of conductive coating peeling in coating methods, simplifying the preparation process, reducing the difficulty of formation, and improving membrane production efficiency.

[0022] This invention utilizes the integrated conductive ceramic membrane as both an anode and a separation membrane in the treatment of oily wastewater. The integrated conductive ceramic membrane as a whole exhibits electrocatalytic activity. In application, a cross-flow electrochemical coupling membrane separation device is employed, using the conductive ceramic membrane as the anode and Al (or Fe) as the cathode, with the membrane filtration process occurring simultaneously during energization. Through voltage-excited electro-oxidation, in-situ electrogenized ROS, electrostatic effects, and electrogenerated bubbles, the integrated conductive ceramic membrane effectively removes pollutants and surface fouling. Attached Figure Description

[0023] Figure 1 The images are SEM images of the integrated Sb-doped SnO2 conductive ceramic film prepared in Example 1. (a) to (d) are SEM images under magnification conditions of 0.5kx, 6kx, 50kx and 100kx, respectively.

[0024] Figure 2 This is a schematic diagram of the contact angle of the integrated Sb-doped SnO2 conductive ceramic film prepared in Example 1;

[0025] Figure 3 Cyclic voltammetry curve of the integrated Sb-doped SnO2 conductive ceramic film prepared in Example 1;

[0026] Figure 4 The image shows the XRD pattern of the monolithic Sb-doped SnO2 conductive ceramic film prepared in Example 1.

[0027] Figure 5 XPS image of the monolithic Sb-doped SnO2 conductive ceramic film prepared in Example 1;

[0028] Figure 6The diagram shows the electrochemical coupling membrane separation and treatment device used in the embodiment, wherein: 1-raw water tank; 2-diaphragm pump; 3-power supply; 4-electrolysis-filtration reactor; 5-product water tank; 6-conductive ceramic membrane; 7-cathode; 8-reflux water regulating valve; 9-product water regulating valve. Detailed Implementation

[0029] In this invention, unless otherwise specified, the raw materials or reagents required for preparation are all commercially available products well known to those skilled in the art.

[0030] This invention provides a method for preparing an integral conductive ceramic film, comprising the following steps:

[0031] A tin source, a metal dopant, an alkaline reagent, and an organic solvent are mixed to carry out a co-precipitation reaction to obtain a precipitated product.

[0032] The precipitated product was subjected to a first calcination to obtain conductive powder.

[0033] The conductive powder, additives, and alcohol solvent are mixed and ball-milled to obtain nano-conductive powder;

[0034] The nano-conductive powder is hydraulically pressed to obtain a tablet;

[0035] The compressed sheet is subjected to a second calcination to obtain an integral conductive ceramic film;

[0036] The metal dopant may contain Sb, Co, Ni, La, Mn, Al, or Zn.

[0037] In this invention, the tin source preferably includes SnCl4 or SnCl2; the alkaline reagent preferably includes ammonia (preferably with a mass concentration of 22-25%), and the pH value is adjusted to the desired value using the alkaline reagent; the organic solvent is preferably ethanol, methanol, or ethylene glycol; and the concentration of the tin source in the organic solvent is preferably 0.5 mol / L (calculated based on the Sn ion concentration).

[0038] In this invention, the metal dopant preferably includes SbCl3, CoCl2, NiCl2, LaCl3, MnCl2, AlCl3 or ZnCl2; the molar amount of the metal element in the metal dopant is preferably 0 to 12% of the Sn element in the tin source and not 0, more preferably 1 to 9%, and even more preferably 3 to 8%.

[0039] In this invention, the tin source is preferably placed in an organic solvent, a metal dopant is added, and after stirring and mixing, an alkaline reagent is added dropwise to reach the desired pH and a co-precipitation reaction is carried out.

[0040] In this invention, the pH of the co-precipitation reaction is preferably 8.0–10, more preferably 8.0; the temperature is preferably 60–100°C, more preferably 70–100°C; and the time is preferably 2–6 h, more preferably 4 h. The dissolved metal ions in the solution are co-precipitated as hydroxide precipitates.

[0041] After the coprecipitation reaction is completed, the present invention preferably uses a vacuum filter for filtration, washes with pure water 5 times, dries, grinds into powder to obtain the precipitated product, and calcines the precipitated product in a muffle furnace.

[0042] In this invention, the temperature of the first calcination is preferably 500–800°C, more preferably 600–700°C, and the time is preferably 1–4 h, more preferably 2–3 h; the heating rate to the first calcination temperature is preferably 5°C / min. This invention transforms the metal hydroxide precipitate formed by the co-precipitation reaction into the corresponding oxide through the first calcination. Simultaneously, during the oxide formation process, substitution doping occurs (Sb replaces the lattice positions of Sn), and the dopant element replaces certain atomic sites in the matrix material, changing the material's conductivity and band structure.

[0043] In this invention, the additives preferably include alumina, zirconium oxide, or silicon carbide; the mass of the additives is preferably 0-60% of the mass of the conductive powder, more preferably 20-50%; this invention utilizes additives to improve the mechanical strength of the integrated film and enhance its stability.

[0044] In this invention, the alcohol solvent is preferably ethanol, and the medium used for the mixed ball milling is preferably zirconia grinding beads. The mass ratio of the total mass of the conductive powder and the additives to the mass ratio of the zirconia grinding beads to the alcohol solvent is preferably 1:2:1; the mixed ball milling time is 1 to 3 hours, more preferably 2 hours.

[0045] After ball milling, the present invention preferably uses a centrifuge to remove the supernatant, and then dries the resulting mixture in an oven at 105°C for 12 hours to obtain nano-conductive powder.

[0046] The present invention preferably places the nano-conductive powder into a circular tableting mold and performs hydraulic pressing using a hydraulic powder tableting machine; the present invention does not have a special limitation on the size of the tablets obtained by hydraulic pressing, which can be adjusted according to actual needs. In the embodiments of the present invention, it is specifically pressed into a circular tablet with a diameter of 30 mm and a thickness of 3 mm.

[0047] In this invention, the hydraulic pressing pressure is preferably 3-9 MPa, more preferably 6-8 MPa, and the stabilization time is preferably 40-80 s, more preferably 60 s.

[0048] In this invention, the temperature of the second calcination is preferably 900–1200°C, more preferably 1000–1200°C, and the time is preferably 1–4 h, more preferably 2–3 h; the heating rate to the second calcination temperature is preferably 5°C / min. This invention achieves effective particle bonding and optimizes the microstructure of the material through the second calcination; it provides sufficient energy to promote particle bonding and interpenetration; and at high temperatures, the diffusion rate of atoms or molecules in the solid material increases, which helps to reverse the reduction of free energy during the sintering process and promote particle adhesion.

[0049] The present invention provides an integral conductive ceramic film prepared by the preparation method described in the above technical solution.

[0050] This invention provides the application of the integrated conductive ceramic membrane described above in wastewater treatment, using a cross-flow electrochemical coupling membrane separation device for wastewater treatment.

[0051] In this invention, such as Figure 6 As shown, the cross-flow electrochemical coupling membrane separation device includes a raw water tank 1, a diaphragm pump 2, a power supply 3, an electrolysis-filtration reactor 4, a product water tank 5, a reflux water regulating valve 8, and a product water regulating valve 9. The raw water tank 1, diaphragm pump 2, electrolysis-filtration reactor 4, and product water tank 5 are connected sequentially. The power supply 3 is connected to the electrolysis-filtration reactor 4. The electrolysis-filtration reactor 4 is equipped with a conductive ceramic membrane 6 and a cathode 7. The reflux water regulating valve 8 is installed in the pipeline between the electrolysis-filtration reactor 4 and the raw water tank 1, and the product water regulating valve 9 is installed in the pipeline between the electrolysis-filtration reactor 4 and the product water tank 5. The conductive ceramic membrane 6 is the integrated conductive ceramic membrane described in the above technical solution. The integrated conductive ceramic membrane serves as the anode.

[0052] The present invention does not have any special limitations on the process of assembling the conductive ceramic membrane 6 and the cathode 7 into the electrolysis-filtration reactor 4. The conductive ceramic membrane 6 and the cathode 7 can be installed in a conventional container to form the electrolysis-filtration reactor 4 in a manner known in the art.

[0053] In this invention, the cathode 7 is preferably an Fe electrode or an aluminum electrode.

[0054] The present invention does not impose any special limitations on the specific structure and connection process of each component in the cross-flow electrochemical coupling membrane separation device; the corresponding components and pipelines known in the art can be used for connection.

[0055] In the cross-flow electrochemical coupling membrane separation device of the present invention, the effluent of the raw water tank 1 is connected to the diaphragm pump 2. Under the pressure of the diaphragm pump 2, the wastewater flows to the electrolysis-filtration reactor 4 and is filtered out from the conductive ceramic membrane and enters the product water tank 5 under pressure. The water flow in the middle of the electrolysis-filtration reactor 4 is controlled by adjusting the return water regulating valve 8, and the return water flows from the electrolysis-filtration reactor 4 to the raw water tank 1.

[0056] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0057] Example 1

[0058] Weigh 13.02565 g (0.05 mol) of SnCl4 and dissolve it in 100 mL of ethylene glycol (i.e., Sn ion concentration of 0.5 mol / L). Add 0.9124 g (0.004 mol) of SbCl3 (Sb molar amount is 8% of Sn) and stir to mix. Add 25% ammonia water dropwise to make the pH of the mixture 8.0. Increase the temperature of the water bath and keep it at 70℃ for 4 hours. Filter the resulting mixture using a vacuum filter, wash it 5 times with pure water, dry it at 105℃ for 12 hours, and grind it into powder. Place the ground powder in a muffle furnace and calcine it at 700℃ for 2 hours with a heating rate of 5℃ / min. Let it cool naturally to obtain conductive powder.

[0059] The conductive powder and alumina were uniformly mixed to obtain a mixed powder, with the mass of alumina being 20% ​​of the mass of the conductive powder. The mixed powder, zirconium oxide ball milling beads, and ethanol were ball milled for 2 hours at a mass ratio of 1:2:1. The mixture was then centrifuged to remove the supernatant and dried in an oven at 105°C for 12 hours to obtain nano-conductive powder.

[0060] 5.0g of nano-conductive powder was placed in a circular tablet mold and stabilized for 60s under a pressure of 6MPa using a hydraulic powder tablet press to form a circular tablet with a diameter of 30mm and a thickness of 3mm. The tablet was then placed in a muffle furnace and heated at 5℃ / min, and calcined at 1200℃ for 2h. After natural cooling, an integrated Sb-doped SnO2 conductive ceramic film was obtained.

[0061] Example 2

[0062] Weigh 13.02565g of SnCl4 and dissolve it in 100mL of ethylene glycol (i.e., Sn ion concentration of 0.5mol / L). Add 0.06491g (0.00065mol) of CoCl2 (Co molar amount is 1% of Sn) and mix and stir. Add 25% ammonia water dropwise to make the pH of the mixture 8.0. Increase the temperature of the water bath and keep it at 70℃ for 4 hours. Filter the resulting mixture using a vacuum filter, wash it 5 times with pure water, dry it at 105℃ for 12 hours, and grind it into powder. Place the ground powder in a muffle furnace and calcine it at 700℃ for 2 hours with a heating rate of 5℃ / min. Let it cool naturally to obtain conductive powder.

[0063] The mass of alumina is 20% of the mass of the conductive powder. The conductive powder and alumina are uniformly mixed to obtain a mixed powder. The mixed powder:zirconia ball milling beads: ethanol mass ratio is 1:2:1. After ball milling for 2 hours, the mixture is centrifuged to remove the supernatant. The mixture is then dried in an oven at 105℃ for 12 hours to obtain nano-conductive powder.

[0064] 5.0g of nano-conductive powder was placed in a circular tablet mold and stabilized for 60s under a pressure of 6MPa using a hydraulic powder tablet press to form a circular tablet with a diameter of 30mm and a thickness of 3mm. The tablet was then placed in a muffle furnace and heated at 5℃ / min, and calcined at 1200℃ for 2h. After natural cooling, an integrated Co-doped SnO2 conductive ceramic film was obtained.

[0065] Example 3

[0066] 13.02565 g of SnCl4 was weighed and dissolved in 100 mL of ethylene glycol (i.e., Sn ion concentration of 0.5 mol / L). 0.50336 g (0.004 mol) of MnCl2 (Mn molar amount is 8% of Sn) was added and mixed. Ammonia solution with a mass concentration of 25% was added dropwise to make the pH of the mixture 8.0. The temperature of the water bath was increased and kept at a constant temperature of 70℃ for 4 hours. The resulting mixture was filtered using a vacuum filter, washed 5 times with pure water, dried at 105℃ for 12 hours, and ground into powder. The ground powder was placed in a muffle furnace and calcined at 700℃ for 2 hours with a heating rate of 5℃ / min. After natural cooling, conductive powder was obtained.

[0067] The conductive powder and alumina were mixed evenly according to the mass ratio of alumina to 20% of the mass of the conductive powder to obtain a mixed powder. The mixed powder, zirconia ball milling beads and ethanol were ball milled for 2 hours according to the mass ratio of mixed powder:zirconia ball milling beads: ethanol = 1:2:1. After that, the mixture was centrifuged to remove the supernatant. The mixture was then dried in an oven at 105℃ for 12 hours to obtain nano-conductive powder.

[0068] 5.0g of nano-conductive powder was placed in a circular tablet mold and stabilized for 60s under a pressure of 6MPa using a hydraulic powder tablet press to form a circular tablet with a diameter of 30mm and a thickness of 3mm. The tablet was then placed in a muffle furnace and heated at 5℃ / min, and calcined at 1200℃ for 2h. After natural cooling, an integrated Mn-doped SnO2 conductive ceramic film was obtained.

[0069] Comparative Example 1

[0070] Commercial porous alumina ceramic membrane (Anhui Tianling Technology Co., Ltd.; Model: pore size 500nm, thickness 4mm, diameter 38mm).

[0071] Comparative Example 2

[0072] 13.02565 g of SnCl4 was weighed and dissolved in 100 mL of ethylene glycol (i.e., Sn ion concentration of 0.5 mol / L) and mixed and stirred. 25% ammonia solution was added dropwise to adjust the pH of the mixture to 8.0. The water bath temperature was increased and kept at 70℃ for 4 hours. The resulting mixture was filtered using a vacuum filter, washed 5 times with pure water, dried at 105℃ for 12 hours, and ground into powder. The ground powder was placed in a muffle furnace and calcined at 700℃ for 2 hours with a heating rate of 5℃ / min, followed by natural cooling to obtain conductive powder.

[0073] The conductive powder and alumina were mixed evenly according to the mass ratio of alumina to 20% of the mass of the conductive powder to obtain a mixed powder. The mixed powder, zirconia ball milling beads and ethanol were ball milled for 2 hours according to the mass ratio of the mixed powder, zirconia ball milling beads and ethanol = 1:2:1. The mixture was then centrifuged to remove the supernatant. The mixture was dried in an oven at 105°C for 12 hours to obtain nano-conductive powder.

[0074] 5.0g of nano-conductive powder was placed in a circular tableting mold and pressed into a circular tablet with a diameter of 30mm and a thickness of 3mm by a hydraulic powder tableting machine under a pressure of 6MPa for 60s. The tablet was then placed in a muffle furnace and heated at 5℃ / min, and calcined at 1200℃ for 2h. After natural cooling, an integrated SnO2 conductive ceramic film was obtained.

[0075] Characterization and performance testing

[0076] Figure 1 The first image shows a SEM image of the integrated Sb-doped SnO2 conductive ceramic film prepared in Example 1; (a) to (d) are SEM images under magnification conditions of 0.5kx, 6kx, 50kx, and 100kx, respectively. The ceramic film is composed of interconnected and stacked spherical particles and has abundant porosity.

[0077] Figure 2This is a schematic diagram of the contact angle of the integrated Sb-doped SnO2 conductive ceramic film prepared in Example 1; it shows that the ceramic film has excellent hydrophilicity and the contact angle is 0°.

[0078] Figure 3 The cyclic voltammetry curve of the integrated Sb-doped SnO2 conductive ceramic film prepared in Example 1 shows that the ceramic film has excellent electrochemical performance.

[0079] Figure 4 The image shows the XRD pattern of the integrated Sb-doped SnO2 conductive ceramic film prepared in Example 1. It can be seen that the conductive ceramic film contains only Sb-doped SnO2 and alumina, and there are no other strong peaks, indicating that the sample has very few impurities and is relatively pure.

[0080] Figure 5 XPS image of the monolithic Sb-doped SnO2 conductive ceramic film prepared in Example 1; confirming the presence of Al, Sn and Sb elements.

[0081] Test case

[0082] 1) The conductivity of the non-ceramic film was tested using the four-point probe resistance method. The results are shown in Table 1.

[0083] Table 1. Conductivity properties of conductive ceramic film materials in Comparative Examples 1-2 and Examples 1-3

[0084]

[0085] As can be seen from Table 1, the modified conductive ceramic film material prepared by the present invention has excellent conductivity, which is significantly better than that of the undoped monolithic SnO2 ceramic film in Comparative Example 2.

[0086] 2) Conduct organic wastewater performance tests on conductive ceramic membrane materials in different cases:

[0087] A conductive ceramic membrane material was used as both the anode and the separation membrane, with Al as the cathode. The initial membrane flux was controlled at 400 LMH, the electrolyte at 10 mM Na₂SO₄, and the current density at 40 mA / cm². 2 Oily wastewater with an emulsified oil content of 2000 mg / L was treated. The results are shown in Table 2.

[0088] Table 2. Removal effect of different conductive ceramic membranes on emulsified oil in wastewater treatment.

[0089]

[0090] As shown in Table 2, the emulsified oil removal rates of the integrated Sb-doped SnO2 conductive ceramic film prepared in Example 1 at 20 min, 40 min, and 60 min were 95.03%, 94.99%, and 95.09%, respectively, and the membrane fluxes were 80.61%, 79.86%, and 79.24%, respectively. This is in contrast to the case without applied current (current density of 0 mA / cm²). 2 The electrochemically coupled membrane separation process significantly improves the removal rate of emulsified oil and the mitigation of membrane fouling.

[0091] As shown in Table 2, the doped conductive ceramic membranes prepared in Examples 1-3 exhibit excellent and stable water flux and high pollutant removal rate in the electrochemical coupling membrane separation reaction device, which are significantly better than the undoped integrated SnO2 ceramic membrane.

[0092] As can be seen from Tables 1-2, the integrated conductive ceramic membrane in Examples 1-3 of the present invention has significantly better conductivity and wastewater treatment efficiency than commercial porous alumina ceramic membrane and undoped integrated SnO2 ceramic membrane.

[0093] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An application of an integrated conductive ceramic membrane in wastewater treatment, characterized in that, Wastewater treatment is carried out using a cross-flow electrochemical coupling membrane separation device; The wastewater is oily wastewater; The cross-flow electrochemical coupling membrane separation device includes a raw water tank (1), a diaphragm pump (2), a power supply (3), an electrolysis-filtration reactor (4), a product water tank (5), a reflux water regulating valve (8), and a product water regulating valve (9). The raw water tank (1), diaphragm pump (2), electrolysis-filtration reactor (4), and product water tank (5) are connected in sequence. The power supply (3) is connected to the electrolysis-filtration reactor (4). The electrolysis-filtration reactor (4) is equipped with a conductive ceramic membrane (6) and a cathode (7). The reflux water regulating valve (8) is installed in the pipeline between the electrolysis-filtration reactor (4) and the raw water tank (1). The product water regulating valve (9) is installed in the pipeline between the electrolysis-filtration reactor (4) and the product water tank (5). The conductive ceramic membrane (6) is an integral conductive ceramic membrane. The method for preparing the integrated conductive ceramic film includes the following steps: A tin source, a metal dopant, an alkaline reagent, and an organic solvent are mixed to carry out a co-precipitation reaction to obtain a precipitated product. The precipitated product was subjected to a first calcination to obtain conductive powder. The conductive powder, additives, and alcohol solvent are mixed and ball-milled to obtain nano-conductive powder; The nano-conductive powder is hydraulically pressed to obtain a tablet; The compressed sheet is subjected to a second calcination to obtain an integral conductive ceramic film; The metal dopant may contain Sb, Co, Ni, La, Mn, Al, or Zn. The molar amount of the metal element in the metal dopant is 0 to 12% of the Sn element in the tin source and is not 0; The additive is aluminum oxide; The coprecipitation reaction is carried out at a pH of 8.0-10, a temperature of 60-100℃, and a time of 2-6 hours.

2. The application according to claim 1, characterized in that, The tin source includes SnCl4 or SnCl2; the alkaline reagent includes ammonia.

3. The application according to claim 1 or 2, characterized in that, The metal dopants include SbCl3, CoCl2, NiCl2, LaCl3, MnCl2, AlCl3, or ZnCl2.

4. The application according to claim 1, characterized in that, The first calcination temperature is 500~800℃, and the time is 1~4 h.

5. The application according to claim 1, characterized in that, The mass of the additive is 0-60% of the mass of the conductive powder and is not zero; the mixing and ball milling time is 1-3 hours; the hydraulic pressing pressure is 3-9 MPa and the stabilization time is 40-80 seconds.

6. The application according to claim 1, characterized in that, The second calcination temperature is 900~1200℃, and the time is 1~4 h.

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