A method for preparing a water-stable MOF-808 membrane and its application in the removal of organic pollutants from saline wastewater.

Abstract

This invention provides a method for preparing a water-stable MOF-808 membrane and its application in the removal of organic pollutants from saline wastewater. The preparation steps of the MOF-808 membrane are as follows: a polymer-modified or seed-coated porous support is subjected to a solvothermal reaction with a precursor solution; after the reaction, the membrane is washed and dried to obtain a polycrystalline MOF-808 membrane. The MOF-808 membrane prepared by this invention has good intergrowth properties and uniform membrane thickness. When used for dye desalination, the obtained MOF-808 membrane has a thickness of 4.37 μm. ‑2 h ‑1 bar ‑1 The membrane exhibits high permeation flux and a salt / dye separation coefficient of 287.3, demonstrating excellent long-term operational stability. It is characterized by low cost / energy consumption and high separation efficiency. Even under acid, alkali, salt, and heating conditions, the MOF-808 membrane remains stable. Based on these characteristics, this membrane material demonstrates excellent separation performance for organic pollutants in high-salt environments, providing a feasible solution for the removal of organic pollutants from saline wastewater.

Description

Technical Field

[0001] This invention belongs to the field of membrane separation, specifically relating to the preparation of a water-stable MOF-808 membrane and its application in the removal of organic pollutants from saline wastewater. Technical Background

[0002] Separation and purification of mixtures has always been one of the most challenging yet crucial aspects of global chemical production. Traditional energy-intensive separation methods, including distillation, adsorption, and crystallization, are often cumbersome, energy-intensive, polluting, and require large land areas. Therefore, the development of novel separation methods is urgently needed. Membrane separation technology is considered a more energy-efficient and environmentally friendly method, offering high separation efficiency and strong continuous operation capabilities, making it a promising new direction for future separation and purification. Metal-organic frameworks (MOFs) are a unique class of porous materials. Thanks to their well-defined pore structure, inherent porosity, high specific surface area, and flexibly tunable functional groups, significant research has been conducted on developing high-performance MOF membranes. However, many MOF materials (such as MOF-177, DMOF-1, UMCM-1, and MOF-5) almost completely lose their crystallinity upon contact with water, severely hindering their application in water treatment. Furthermore, most current MOF membranes exhibit poor operational / hydrothermal stability and are susceptible to problems related to acids, alkalis, salts, and heat, posing significant challenges to practical applications, particularly in water treatment. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a method for preparing a water-stable MOF-808 membrane and its application in the removal of organic pollutants from saline wastewater. By modifying a porous support with a polymer, the polar groups in the polymer chains interact with the Zr in the MOF-808 framework. 4+ Strong ion affinity increases heterogeneous nucleation density, enabling in-situ growth of MOF-808 membranes on porous supports. Simultaneously, a dense MOF-808 membrane is prepared by secondary growth under the same conditions using a support coated with MOF-808 seed crystals. The resulting MOF-808 membrane exhibits excellent separation performance and outstanding hydrothermal / chemical stability. The above process is simple, highly operable, and shows promising prospects for industrial applications.

[0004] The suitable pore size of MOF-808 not only ensures high diffusivity for smaller ions but also effectively intercepts larger solute molecules. Therefore, MOF-808 exhibits more advantages than other materials in precise and rapid membrane separation. Furthermore, combining its contrasting retention effects on simple salts (such as NaCl) and large dyes with the inherent structural stability of its framework in aqueous environments, MOF-808 membranes achieve highly efficient and selective separation of dye molecules from simple metal ions through size sieving.

[0005] The technical solution of this invention is:

[0006] A method for preparing a MOF-808 membrane with excellent water stability includes the following steps:

[0007] (1) Dry the polymer-modified or seed-coated porous carrier to obtain the modified porous carrier.

[0008] (2) Mix the reaction solvent, regulator, 1,3,5-pyromellitic acid and zirconium source evenly to form a precursor solution;

[0009] (3) The modified porous support and precursor solution were loaded into a reaction vessel and reacted at 20-200℃ for 1-168h.

[0010] (4) After the reaction is completed, the MOF-808 polycrystalline film with good intergrowth properties is obtained by washing and drying.

[0011] When the polymer is preferably modified, the solvent for dissolving the polymer includes water, ethanol, toluene, N,N-dimethylformamide, N-methylformamide, methanol, chloroform, dichloroethane, or tetrachloromethane.

[0012] The preferred polymer used to modify the porous support in step (1) includes 3-aminopropyltriethoxysilane, polydopamine, polyvinylpyrrolidone, or polyaniline.

[0013] The preferred method for modifying the polymer precursor in step (1) includes solvothermal method, impregnation method, liquid phase growth method or simple spin coating process.

[0014] The porous carrier in preferred step (1) includes one or more of porous metals, porous metal oxides, porous non-metal oxides, carbides and porous polymers; the porous carrier structure includes tubular structure, flat plate structure, hollow fiber structure or spiral structure.

[0015] The preferred reaction solvent in step (2) includes one or more of formamide, N,N-dimethylacetamide, N,N-dimethylformamide, diethylacetamide, and acetone; the zirconium source includes zirconium chloride, zirconium disulfide, zirconium propoxide, zirconium oxychloride, zirconium sulfate, zirconium nitrate, zirconium sulfide, or zirconium acetate; the regulator includes acetic acid, formic acid, hydrochloric acid, sulfuric acid, trifluoroacetic acid, or benzoic acid.

[0016] The preferred molar ratio of 1,3,5-pyromellitic acid, zirconium source and regulator in the precursor solution in step (2) is 0.1-10:1:0-1100.

[0017] The preferred method for heating the reaction in step (3) is oven heating or microwave heating.

[0018] The preferred reagent for washing the membrane in step (4) is at least one of water, ethanol, methanol, N,N-dimethylformamide and acetone.

[0019] The MOF-808 film prepared by the above method provided by the present invention has high crystallinity and excellent intergrowth, with a grain size of 0.2-5 μm and a film thickness of 0.5-10 μm.

[0020] The present invention also provides an application of MOF-808 membrane in the removal of organic pollutants from saline wastewater.

[0021] Furthermore, the aforementioned MOF-808 membrane was used for the removal of organic pollutants from saline wastewater. This material was first investigated for the separation of a simple salt (NaCl) at a salt solution concentration of 2 g / L, and ion sieving tests were conducted under a pressure difference of 0.1 MPa. + The rejection rate was only 6.3%. The tested membrane was used to separate various organic pollutants and dyes. The material was then applied to the removal of organic pollutants from saline wastewater, given MOF-808's effectiveness against Na+. + In stark contrast to the high rejection rates of various dyes, the MOF-808 membrane was tested for dye desalination (removal of organic pollutants from saline wastewater). Experimental results demonstrated that the obtained MOF-808 membrane exhibited a rejection rate of 4.37 μm. -2 h -1 bar -1 The membrane exhibits high permeation flux and a salt / dye separation coefficient of 287.3, demonstrating excellent application prospects for the removal of organic pollutants from saline wastewater.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] This invention first employs a polymer-modified support in-situ growth and seed coating for epitaxial growth under solvothermal conditions to prepare a high-performance membrane with uniform growth, uniform thickness, and relatively complete structure. The two methods provided by this invention have low preparation costs and strong universality. The pores of the MOF-808 membrane material can be used to achieve precise sieving of simple salts and organic pollutants. The MOF-808 membrane prepared by this method has the following characteristics: (1) good hydrothermal stability, membrane structure, and the inherent pore diameter of the material itself. Its characteristic of being exactly between hydrated ions and dye molecules not only ensures efficient retention of large-sized dye molecules, but also ensures effective permeation of small-sized hydrated metal ions, while minimizing the impact on water permeation flux; (2) Under different operating pressures (0.1-0.5MPa), the well-dense MOF-808 membrane for Na + (2) It maintains relatively stable separation performance of various dye molecules; (3) It has excellent dye / salt separation performance, with a selectivity of up to 287.3 and a water permeation flux of 4.37 Lm. -2 h -1 bar -1 (4) It exhibits good stability. When immersed in 0.2wt% NaCl, pH=1, pH=4 and pH=10 environments for a long time, the MOF-808 membrane can still remain stable and no cracks or pinholes were observed. Attached Figure Description

[0024] Figure 1 XRD of the MOF-808 film prepared on the porous alumina support surface modified with 3-aminopropyltriethoxysilane in Example 2;

[0025] Figure 2 Scanning electron microscope (SEM) image of the MOF-808 film prepared in Example 2;

[0026] Figure 3 XRD of MOF-808 film prepared on the surface of polydopamine-modified porous alumina support in Example 4;

[0027] Figure 4 SEM image of the MOF-808 membrane prepared in Example 4;

[0028] Figure 5 The XRD patterns of MOF-808 films synthesized at different time periods of 12–48h in Example 4 are shown. The diffraction peaks of MOF-808 and α-Al2O3 phases are marked as black and white triangles, respectively.

[0029] Figure 6 SEM image of the MOF-808 membrane prepared in Example 6;

[0030] Figure 7XRD patterns of MOF-808 seed crystals and MOF-808 films prepared for Examples 7 and 8;

[0031] Figure 8 SEM image of MOF-808 seed crystals prepared for Example 7;

[0032] Figure 9 SEM image of the MOF-808 membrane prepared in Example 8;

[0033] Figure 10 The permeation flux and rejection rate of the prepared MOF-808 membrane for different dye molecules were determined.

[0034] Figure 11 Long-term stability test of the MOF-808 membrane prepared in Example 2 after 48 hours of reaction with CR solution;

[0035] Figure 12 The permeation flux and rejection rate of the prepared MOF-808 membrane to various NaCl / dye mixed solutions were determined.

[0036] Figure 13 SEM images of the prepared MOF-808 membrane after soaking in 0.2 wt% NaCl (pH=7) solution for 72 h;

[0037] Figure 14 SEM images of the prepared MOF-808 membrane after soaking in a solution at pH = 1 for 72 h;

[0038] Figure 15 SEM images of the prepared MOF-808 membrane after soaking in a solution at pH 4 for 72 h;

[0039] Figure 16 SEM images of the prepared MOF-808 membrane after soaking in a solution at pH = 10 for 72 h.

[0040] Figure 17 SEM image of the prepared MOF-808 membrane after heat treatment in water at 70℃ for 72 h;

[0041] Figure 18 XRD of the prepared MOF-808 membrane after heat treatment at pH = 1, 4, 7, 10 and 70 °C;

[0042] Figure 19 SEM image of MOF-808 film prepared by direct in-situ growth in Comparative Example 1;

[0043] Figure 20 SEM image of the MOF-808 membrane prepared by reacting for 12 hours in Comparative Example 2;

[0044] Figure 21For comparison, SEM images of the MOF-808 membrane prepared after 24 hours of reaction in Example 3 were used.

[0045] Figure 22 SEM image of the MOF-808 membrane prepared by reacting for 36 hours in Comparative Example 4. Detailed Implementation

[0046] The present invention will be further illustrated below with specific examples. These examples will help researchers and technicians in the art to further understand the present invention. Once those skilled in the art understand the concept of the present invention, they can make changes, modifications, or even improvements to the following examples. Therefore, these should all fall within the protection scope of the present invention.

[0047] Example 1: 3-Aminopropyl-triethoxysilane modified porous alumina support

[0048] (1) Dissolve 0.5 mL of polymer 3-aminopropyl-triethoxysilane in 40 mL of toluene by ultrasonication, then place the porous tubular alumina carrier with both ends sealed into it and heat it in a solvothermal oven at 110 °C for 3 h.

[0049] (2) After the reaction is complete, remove the carrier and let it air dry for later use.

[0050] Example 2: In-situ preparation of MOF-808 membranes using a solvothermal method

[0051] (1) Mix 15 mL of N,N-dimethylformamide and 15 mL of formic acid in equal volumes, and sonicate 0.083 g of ZrOCl2·8H2O and 0.121 g of 1,3,5-pyromellitic acid into the above binary solution;

[0052] (2) The modified porous alumina support (both ends sealed with Teflon rubber stoppers and tape) in Example 1 was vertically placed into a reaction vessel containing the above precursor solution and reacted in a convection oven at 140°C for 48 hours.

[0053] (3) After the reaction is complete, cool to room temperature, take out the synthesized membrane, wash it with N,N-dimethylformamide and ethanol in sequence, and dry it at room temperature.

[0054] XRD spectrum ( Figure 1 The characteristic diffraction peaks of MOF-808 were observed, confirming the formation of the MOF-808 phase on the 3-aminopropyl-triethoxysilane-modified alumina support. Combined with SEM (…), the characteristic diffraction peaks of MOF-808 were observed. Figure 2 Further evidence shows that under these conditions, MOF-808 films with grain size of 2-3 μm, film thickness of ~2.5 μm, good intergranular intergrowth, continuous and dense film layers without obvious defects can be generated.

[0055] Example 3: Polydopamine-modified porous alumina carrier

[0056] (1) Dissolve 0.316g of dopamine hydrochloride in 60mL of water by ultrasonication, and then put the porous aluminum carrier with both ends sealed into it and soak for 24h.

[0057] (2) Dissolve 0.423g of hydroxymethylaminomethane in 45mL of water, soak the above carrier for 36h, then take it out and wash it with a lot of deionized water, and let it air dry for later use.

[0058] Example 4: In-situ preparation of MOF-808 membrane using a solvothermal method

[0059] The specific implementation steps are the same as in Example 2, except that the carrier is replaced with the polydopamine-modified carrier in Example 3.

[0060] XRD Figure 3 The spectrum shows characteristic diffraction peaks of MOF-808, confirming the formation of the MOF-808 phase on the polydopamine-modified alumina support. Combined with SEM... Figure 4 Further evidence shows that under these conditions, MOF-808 films with a grain size of ~4μm, a film thickness of ~2.2μm, good intergranular intergrowth, continuous and dense film layers without obvious defects can be generated.

[0061] Example 5: Polyvinylpyrrolidone modified porous alumina carrier

[0062] (1) Dissolve 0.4g of polymer polyvinylpyrrolidone in 40mL of ethanol by ultrasonication, then place the porous alumina carrier with sealed ends into it and heat it in an oven at 120℃ for 4h.

[0063] (2) After the reaction is complete, the carrier is removed and placed in a 70°C oven to dry for later use.

[0064] Example 6: In-situ preparation of MOF-808 membrane using a solvothermal method

[0065] The specific implementation steps are the same as in Example 2, except that the carrier is the polyvinylpyrrolidone modified carrier in Example 5.

[0066] XRD Figure 5 d) The spectrum shows characteristic diffraction peaks of MOF-808, proving the formation of the MOF-808 phase on the polyvinylpyrrolidone-modified alumina support. Combined with SEM (… Figure 6 Further evidence shows that under these conditions, MOF-808 films with a grain size of ~3μm, a film thickness of ~3.4μm, good intergranular intergrowth, continuous and dense film layers without obvious defects can be generated.

[0067] Example 7: Preparation of MOF-808 seed crystals

[0068] (1) Dissolve 0.356g of zirconium salt in a mixture of N,N-dimethylformamide / formic acid, and then add 1.361g of 1,3,5-pyromellitic acid and dissolve by sonication;

[0069] (2) MOF-808 seed crystals were generated by standing the precursor solution in an oven at 130°C for 12 hours. The seed crystals were then washed with N,N-dimethylformamide / ethanol alternately, centrifuged, and dried overnight in a vacuum oven at 70°C.

[0070] MOF-808 seed crystal SEM ( Figure 7 This indicates that the prepared seed crystals are uniform in size, with a dimension of 500 nm. The corresponding XRD diffraction peaks ( Figure 8 It was confirmed to be a pure phase MOF-808.

[0071] Example 8: Preparation of MOF-808 film by epitaxial growth

[0072] The specific implementation steps are the same as in Example 2, except that the carrier is the alumina carrier coated with MOF-808 seed crystals in Example 7, and the reaction temperature is reduced to 70°C and the reaction time is extended to 96 hours.

[0073] XRD Figure 8 The spectrum shows characteristic diffraction peaks of MOF-808, proving the formation of the MOF-808 phase on the coated alumina support. Combined with SEM... Figure 9 Further evidence shows that under these conditions, MOF-808 films with a grain size of 3-4 μm, a film thickness of ~2.2 μm, good intergranular intergrowth, continuous and dense film layers without obvious defects can be generated.

[0074] Example 9: Test of MOF-808 membrane's retention performance for simple salt (NaCl)

[0075] The MOF-808 membranes prepared in Examples 6 and 8 were subjected to simple salt (NaCl) rejection performance tests under the following conditions: at room temperature (20±1℃), transmembrane pressure difference of 0.1MPa, membrane surface flow rate of 1.7m / s, and salt concentration of 2g / L, cross-flow separation tests were conducted.

[0076] The ion separation performance of the corresponding MOF-808 membranes is shown in Table 1. The MOF-808 membranes prepared by in-situ growth have good ion separation performance for Na+. + The rejection rate was 6.3%, and the permeation flux was 6.03 L / m³. -2 h -1 bar -1 MOF-808 films prepared by spin-coating seed epitaxial growth for Na + The rejection rate was 13.4%, and the permeation flux was 2.67 L / m³. -2 h-1 bar -1 The above results indicate that the MOF-808 film prepared using polymer-modified alumina support and seed-assisted epitaxial growth effectively resists Na+. + Its low rejection rate lays the foundation for the subsequent use of MOF-808 in dye desalination (intercepting large molecular dyes while allowing smaller hydrated ions to permeate).

[0077] Table 1. Separation performance of MOF-808 membrane for simple salt solutions

[0078]

[0079] Example 10: Dye Retention Test of MOF-808 Membrane

[0080] Following the NaCl separation test, the MOF-808 membrane prepared in Example 6 was further tested for dye rejection performance. Four dyes were used: malachite green (MG), methylene blue (MB), Congo red (CR), and calcein (CC), with a concentration of 0.5 g / L for each. The test conditions were as follows: cross-flow separation test was conducted at room temperature (20 ± 1 °C), transmembrane pressure difference of 0.1 MPa, and membrane surface flow velocity of 1.7 m / s.

[0081] Test results show ( Figure 10 The MOF-808 membrane exhibits a high rejection rate of 99.8% for various dyes, with a permeation flux of 4.79 L / m³. -2 h -1 bar -1 Taking CR as an example, the long-term stability of the prepared membrane was examined. Figure 11 After 96 hours of continuous flow rejection testing, the membrane's permeation flux and rejection rate did not show significant decrease, fully demonstrating the membrane's excellent operational stability.

[0082] Example 11: Salt dye rejection test of MOF-808 membrane

[0083] After the organic matter separation test, the MOF-808 membrane prepared in Example 6 was further subjected to salt dye retention test. The test conditions were as follows: at room temperature (20±1℃), transmembrane pressure difference was 0.1MPa, membrane surface flow rate was 1.7m / s, salt concentration was 2g / L, and dye concentration was 0.5g / L for cross-flow separation test.

[0084] When both salt and dye are present in the feed solution, the water permeation flux decreases. Figure 12 One plausible reason is that dye molecules may partially adhere to the membrane surface, or even clog the pores of the MOF-808 membrane, leading to a reduction in the flux of the salt / dye mixture (4.37 L m). -2 h -1 bar-1 ), and Na + The ion rejection rate increased (from 6.3% to 23%). Nevertheless, the MOF-808 membrane still showed a high rejection rate for dyes (rejection rate of >99.0% for various dyes) and a salt / dye separation coefficient as high as 287.3.

[0085] Example 12: Stability test of MOF-808 membrane

[0086] The MOF-808 membrane prepared in Example 6 was immersed in harsh aqueous solutions of salt (0.2 wt% NaCl), acid (pH = 1 and 4), and alkali (pH = 10) for 72 hours. Figure 13-16 Meanwhile, the film was treated at 70°C for 24 hours to examine its thermal stability. Figure 17 The results showed that the MOF-808 film surface had almost no cracks or pinholes. Slight differences in peak intensity could be observed in the XRD patterns of the MOF-808 films. Figure 18 However, its characteristic diffraction peaks remain unchanged, indicating that the membrane can withstand long-term exposure to harsh environments and exhibits good chemical / thermal stability.

[0087] Comparative Example 1: MOF-808 membrane prepared in situ using a solvothermal method on an unmodified support.

[0088] The specific implementation steps are the same as in Example 2, except that the alumina support used in step (2) is replaced with an alumina support that is not modified by polymer.

[0089] SEM Figure 19 The results showed that only a few scattered grains were scattered on the surface of the carrier and the vast majority of the carrier remained exposed, proving that the carrier without PVP modification is not easy to form a dense MOF-808 film.

[0090] Comparative Example 2: In-situ preparation of MOF-808 membranes using a solvothermal method with single controlled reaction time

[0091] The specific implementation steps are the same as in Examples 1 and 2, except that the solvothermal reaction time in step (2) of Example 2 is changed to 12h.

[0092] XRD Figure 5 a) No characteristic peaks of MOF-808 were observed in the spectrum; SEM ( Figure 20 It can be observed that the surface of the carrier is discretely covered with an amorphous gel layer, indicating that MOF-808 has undergone heterogeneous nucleation.

[0093] Comparative Example 3: In-situ preparation of MOF-808 membranes using a solvothermal method with single controlled reaction time

[0094] The specific implementation steps are the same as in Examples 1 and 2, except that the solvothermal reaction time in step (2) of Example 2 is changed to 24h.

[0095] When the reaction time was extended from 12 h in Comparative Example 1 to 24 h, XRD ( Figure 5 b) The MOF-808 phase was still not observed in the spectrum; similarly, the corresponding SEM ( Figure 21 After 24 hours of reaction, gel sedimentation continues, and the surface of the carrier is basically completely covered by the gel.

[0096] Comparative Example 4: In-situ preparation of MOF-808 membranes using a solvothermal method with single controlled reaction time

[0097] The specific implementation steps are the same as in Examples 1 and 2, except that the solvothermal reaction time in step (2) of Example 2 is changed to 36h.

[0098] The XRD (5c) spectrum begins to show the diffraction characteristic peaks of the MOF-808 phase, and the SEM (5c) spectrum also shows these characteristics. Figure 22 Crystalline phase formation can also be observed in the reaction. Therefore, by examining different reaction times, controlling the reaction time under optimal formulation and reaction conditions is an effective means to prepare high-performance MOF-808 films.

[0099] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0100] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. Use of MOF-808 membranes in the removal of organic pollutants from salt-containing wastewater, characterized in that: The MOF-808 film is prepared by the following steps: (1) drying the polymer-modified porous carrier to obtain a modified porous carrier; (2) mixing a reaction solvent, a regulator, 1,3,5-benzenetricarboxylic acid and a zirconium source to form a precursor solution; (3) loading the modified porous carrier and the precursor solution into a reaction kettle and reacting at 20-200 ℃ for 1-168 h; (4) after the reaction, washing and drying to obtain a MOF-808 film with good intergrowth; In step (2), the molar ratio of 1,3,5-benzenetricarboxylic acid, the zirconium source and the regulator in the precursor solution is 0.1-10:1:0-1100; the polymer includes 3-aminopropyl-triethoxysilane, polydopamine, polyvinylpyrrolidone or polyaniline.

2. Use of a MOF-808 membrane according to claim 1 for the removal of organic pollutants from salt-containing wastewater, characterized in that: When the polymer is modified, solvents for dissolving the polymer include: water, ethanol, toluene, N,N dimethylformamide, N- methylformamide, methanol, chloroform, dichloroethane, or tetrachloromethane.

3. Use of a MOF-808 membrane according to claim 1 for the removal of organic pollutants from salt-containing wastewater, characterized in that: In step (1), the polymer modification method includes a solvothermal method, an immersion method, a liquid phase growth method or a spin coating process.

4. Use of a MOF-808 membrane according to claim 1 for the removal of organic pollutants from salt-containing wastewater, characterized in that: In step (1), the porous carrier includes one or more of a porous metal, a porous metal oxide, a porous non-metal oxide, a carbide and a porous polymer; the structure of the porous carrier includes a tubular structure, a flat plate structure, a hollow fiber structure or a roll structure.

5. Use of a MOF-808 membrane according to claim 1 for the removal of organic pollutants from salt containing wastewater, characterized in that: The reaction solvent in Step (2) includes formamide, N,N - dimethylacetamide, N,N - one or more of dimethylformamide, diethylacetamide and acetone.

6. Use of a MOF-808 membrane according to claim 1 for the removal of organic pollutants from salt containing wastewater, characterized in that: In step (2), the zirconium source includes zirconium chloride, zirconium disulfide, zirconium n-propylate, zirconium oxychloride, zirconium sulfate, zirconium nitrate, zirconium sulfide or zirconium acetate; the regulator includes acetic acid, formic acid, hydrochloric acid, sulfuric acid, trifluoroacetic acid or benzoic acid.

7. Use of a MOF-808 membrane as claimed in claim 1 for the removal of organic pollutants from salt containing wastewater, characterized in that: The MOF-808 film has high crystallinity and good intergrowth, with a grain size of 0.2-5 μm and a film thickness of 0.5-10 μm.

8. Use of MOF-808 membrane as claimed in claim 1 for removal of organic pollutants from salt containing wastewater characterized by: The MOF-808 film is used for removing organic pollutants from salt-containing wastewater.

Images