A montmorillonite membrane catalytic material with ion intercalation and a preparation method thereof, a flow membrane reactor and application thereof

Abstract

The application relates to a montmorillonite film catalytic material with ion intercalation and a preparation method thereof, a flow film reactor and application thereof. The preparation method comprises the following steps: (1) a montmorillonite nanosheet dispersion liquid is sequentially subjected to vacuum film preparation and vacuum-assisted assembly treatment to obtain a montmorillonite two-dimensional film; and (2) the montmorillonite two-dimensional film in step (1) is sequentially subjected to ion solution treatment and heat treatment to obtain the montmorillonite film catalytic material with ion intercalation. When the montmorillonite film catalytic material with ion intercalation prepared by the preparation method is applied to the flow film reactor, phenolic compounds can be rapidly oxidatively degraded at room temperature, and the montmorillonite film catalytic material is suitable for oxidative degradation of phenolic compounds with different reaction activities and molecular weights.

Description

Technical Field

[0001] This application relates to the field of catalytic materials technology, and in particular to a montmorillonite membrane catalytic material with ion intercalation, its preparation method, a flow membrane reactor, and its application in the oxidative degradation of phenolic compounds. Background Technology

[0002] Phenolic compounds are a general term for organic compounds in which hydroxyl groups are directly attached to the carbon atoms of aromatic rings (such as benzene, naphthalene, and anthracene rings). They mainly include phenol, cresol, xylenol, chlorophenol, and nitrophenol. These substances are widely used in coking, pharmaceutical, petrochemical, pesticide manufacturing, and plastics industries, and are typical emerging pollutants. Due to the stability of their aromatic ring structures, phenolic compounds are more difficult to rapidly degrade through microbial action in the natural environment.

[0003] Currently, the treatment of phenol-containing wastewater faces significant challenges. Traditional biological treatment methods are often inefficient for high-concentration or highly toxic phenolic wastewater, and can even lead to microbial poisoning. Although advanced oxidation technologies (AOPs) such as Fenton oxidation and photocatalytic oxidation have demonstrated high degradation efficiency in laboratory studies, they still face problems such as high cost and difficulty in catalyst recovery in practical engineering applications. The main bottleneck of traditional homogeneous Fenton technology lies in its stringent requirements for reaction conditions and the high cost of subsequent treatment. Traditional processes typically require operation in a strongly acidic environment (pH 2.0-3.0) to maintain the dissolved state of iron ions and prevent their precipitation and deactivation. However, actual industrial wastewater is often neutral or alkaline, which necessitates the consumption of large amounts of acid and alkali reagents for pH adjustment in practical applications, increasing treatment costs and generating large amounts of saline wastewater. Furthermore, residual iron ions need to be removed through neutralization and precipitation, a process that generates large amounts of iron sludge, not only wasting iron resources but also creating serious secondary solid waste pollution and disposal problems. While existing heterogeneous catalysis has addressed the iron sludge problem to some extent, it still faces challenges in practical applications, including mass transfer limitations and low utilization of active sites. Traditional powdered heterogeneous catalysts require separation by sedimentation or filtration after the reaction, a time-consuming process that easily leads to catalyst loss. Furthermore, powdered catalysts tend to agglomerate in static reaction systems, reducing their specific surface area and hindering the contact of internal active sites with reactants, thus lowering catalytic efficiency. In addition, static batch processing modes are insufficient for continuous large-scale wastewater treatment, limiting their application potential in industrial settings.

[0004] Therefore, there is an urgent need in this field to develop a method for the rapid oxidative degradation of phenolic compounds in order to solve the problems of low efficiency and high cost in existing phenolic compound degradation processes. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides an ion-intercalated montmorillonite membrane catalytic material, its preparation method, a flow membrane reactor, and its application. The preparation method of the ion-intercalated montmorillonite membrane catalytic material is simple, convenient, and uses readily available raw materials. The resulting ion-intercalated montmorillonite membrane catalytic material exhibits excellent catalytic effects on the oxidative degradation of phenolic compounds. The flow membrane reactor containing the ion-intercalated montmorillonite membrane catalytic material can achieve rapid (≤50 s) oxidative degradation of phenolic compounds at room temperature, and is suitable for the oxidative degradation of phenolic compounds with different reactivity and molecular weights.

[0006] To achieve this objective, the following technical solution is adopted in this application: In a first aspect, this application provides a method for preparing a montmorillonite membrane catalytic material with ion intercalation, the method comprising the following steps: (1) Montmorillonite nanosheet dispersion was subjected to vacuum film formation and vacuum-assisted assembly treatment in sequence to obtain a two-dimensional montmorillonite film; (2) The montmorillonite two-dimensional membrane described in step (1) is subjected to ion solution treatment and heat treatment in sequence to obtain montmorillonite membrane catalyst material with ion intercalation.

[0007] The preparation method provided in this application is simple and convenient, and the raw materials are readily available. It involves vacuum-forming montmorillonite nanosheets and then regularly stacking them under negative pressure to form a montmorillonite membrane with uniform two-dimensional channels. Subsequently, through ion solution treatment, the enrichment effect of the two-dimensional channels is utilized to achieve the purpose of ion insertion into the two-dimensional interlayer channels of montmorillonite. Finally, after heat treatment, a montmorillonite membrane catalytic material with ion intercalation that has excellent catalytic effect on the oxidative degradation reaction of phenolic compounds is obtained.

[0008] A flow membrane reactor containing the ion-intercalated montmorillonite membrane catalyst can effectively achieve dynamic catalysis for the oxidative degradation of phenolic compounds through continuous phase cascade reactions. This enables rapid (≤50 s) and efficient (reaction conversion rate up to 90%) oxidative degradation of phenolic compounds at room temperature. It is suitable for the oxidative degradation of phenolic compounds with different reactivity and molecular weights, effectively solving the problems of low efficiency and high cost in existing static batch treatment of phenolic compounds, and thus well meeting the demand for efficient and low-cost treatment of phenol-containing industrial wastewater.

[0009] In some embodiments, the montmorillonite nanosheet dispersion in step (1) is prepared by mixing montmorillonite with a solvent and then subjecting it to a freeze-heat cycle.

[0010] In this application, during a freeze-heat cycle, the movement of water molecules during the cycle causes the montmorillonite layered structure to expand, thereby producing montmorillonite nanosheets.

[0011] In some embodiments, the solvent includes water.

[0012] In some embodiments, the mixing method includes ultrasound and / or stirring.

[0013] In some embodiments, the mixing method is a combination of ultrasound and stirring.

[0014] In some embodiments, the mixing time is 1-20 h, for example, it can be 1 h, 3 h, 5 h, 7 h, 10 h, 12 h, 14 h, 16 h, 18 h or 20 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0015] In some embodiments, the concentration of montmorillonite in the system after mixing with the solvent is 0.5-10 mg / mL, for example, it can be 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, 8 mg / mL or 10 mg / mL, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0016] In some embodiments, the mixing includes ultrasonic treatment at 200-800 W for 1-5 min followed by stirring for 10-15 h; wherein, 1-5 min can be, for example, 1 min, 1.5 min, 2 min, 2.5 min, 3 min, 3.5 min, 4 min, 4.5 min, or 5 min, and 10-15 h can be, for example, 10 h, 10.5 h, 11 h, 11.5 h, 12 h, 12.5 h, 13 h, 13.5 h, 14 h, 14.5 h, or 15 h, and specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0017] In some embodiments, the freezing temperature in the freezing-heating cycle is -78°C to 0°C, for example, it can be -78°C, -70°C, -60°C, -50°C, -45°C, -40°C, -30°C, -20°C, -10°C, -4°C or 0°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0018] In some embodiments, the freezing temperature in the freezing-heating cycle is -45°C to -10°C, for example, it can be -45°C, -40°C, -35°C, -30°C, -25°C, -20°C, -15°C or -10°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0019] In some embodiments, the freezing time in the freeze-heat cycle is 1-48 h, for example, it can be 1 h, 5 h, 10 h, 15 h, 20 h, 25 h, 30 h, 35 h, 40 h, 45 h or 48 h, as well as specific point values ​​between the above points. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0020] In some embodiments, the freezing time in the freezing-heating cycle is 5-25 h, for example, it can be 5 h, 8 h, 10 h, 12 h, 15 h, 18 h, 20 h, 22 h or 25 h, as well as specific point values ​​between the above points. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0021] In some embodiments, the heating temperature in the freezing-heating cycle is 25-90°C, for example, it can be 25°C, 30°C, 40°C, 450°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0022] In some embodiments, the heating temperature in the freezing-heating cycle is 60-90°C, for example, it can be 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0023] In some embodiments, the heating time in the freezing-heating cycle is 1-24 h, for example, it can be 1 h, 3 h, 5 h, 7 h, 10 h, 12 h, 15 h, 17 h, 20 h, 22 h or 24 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0024] In some embodiments, the heating time in the freeze-heat cycle is 1-10 h, for example, it can be 1 h, 3 h, 5 h, 7 h or 10 h, and specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0025] In some implementations, the number of freezing-heating cycles is 1 to 5 times, for example, 1 time, 2 times, 3 times, 4 times or 5 times.

[0026] In some implementations, a dispersive step is also included between two adjacent freeze-heat cycles.

[0027] In some embodiments, the dispersion method includes stirring at 20-30°C for 1-144 h, wherein 20-30°C can be, for example, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, or 30°C, and 1-144 h can be, for example, 1 h, 5 h, 10 h, 12 h, 15 h, 17 h, 20 h, 30 h, 50 h, 100 h, or 144 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0028] In some embodiments, the freeze-heat cycle is followed by a centrifugation step.

[0029] In some embodiments, the supernatant is collected by centrifugation to obtain the montmorillonite nanosheet dispersion.

[0030] It should be noted that there is no special limitation on the centrifugation speed in this application; conventional speeds in the art are applicable, including but not limited to 4000 rpm.

[0031] In some embodiments, the montmorillonite nanosheet dispersion is obtained by collecting the supernatant after centrifugation.

[0032] In some embodiments, the minimum length (diameter) of the montmorillonite nanosheets in the montmorillonite nanosheet dispersion in step (1) is ≥60 nm, for example, it can be 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm or 120 nm, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0033] In some embodiments, the average thickness of the montmorillonite nanosheets in the montmorillonite nanosheet dispersion in step (1) is 1.2-5 nm, for example, it can be 1.2 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm or 5 nm, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0034] In some embodiments, the vacuum film formation in step (1) includes diluting the montmorillonite nanosheet dispersion and then vacuum filtering it until the solvent is dried to obtain an initial film.

[0035] In some embodiments, the dilution process includes diluting the montmorillonite nanosheet dispersion with a solvent to a ratio of 3-5 times, for example, 3 times, 4 times or 5 times.

[0036] In some embodiments, the relative vacuum degree of the vacuum filtration is -0.6 to -0.9 atm, for example, it can be -0.6 atm, -0.65 atm, -0.7 atm, -0.75 atm, -0.8 atm, -0.85 atm or -0.9 atm, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0037] In some embodiments, the relative vacuum degree of the vacuum-assisted assembly process in step (1) is -0.6 to -0.9 atm, for example, it can be -0.6 atm, -0.65 atm, -0.7 atm, -0.75 atm, -0.8 atm, -0.85 atm or -0.9 atm, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0038] In some embodiments, the vacuum-assisted assembly process in step (1) takes 10-16 hours, for example, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours or 16 hours, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0039] In some implementations, the vacuum-assisted assembly process in step (1) is performed by vacuum filtration.

[0040] In some embodiments, the ionic solution in step (2) is a salt solution.

[0041] In some embodiments, the cations in the ionic solution include any one or a combination of at least two of nickel ions, cobalt ions, ferric ions, or ferrous ions.

[0042] In some embodiments, the anions in the ionic solution include any one or a combination of at least two of halide ions, sulfate ions, or nitrate ions.

[0043] In some embodiments, the ionic solution in step (2) includes any one or a combination of at least two of the following: NiCl2 solution, CoCl2 solution, Fe2(SO4)3 solution, Fe(NO3)3 solution, FeCl3 solution, FeSO4 solution, Fe(NO3)2 solution, or FeCl2 solution.

[0044] In some embodiments, the concentration of cations in the ionic solution in step (2) is 10. -5 -10 -1 mol / L, for example, can be 1×10 -5 mol / L, 5×10 -5 mol / L, 1.0×10 -4 mol / L, 5×10 -4 mol / L, 1×10 -3 mol / L, 5×10 -3 mol / L, 1×10 -2 mol / L, 5×10 -2 mol / L or 1×10 -1 The specific point values ​​between the above-mentioned mol / L values ​​are not exhaustively listed here due to space limitations and for the sake of brevity.

[0045] In some embodiments, the concentration of cations in the ionic solution in step (2) is 10. -4 -10 -2 mol / L, for example, could be 1.0 × 10⁻⁶. -4 mol / L, 5×10 -4 mol / L, 1×10 -3 mol / L, 5×10 -3 mol / L or 1×10 -2 The specific point values ​​between the above-mentioned mol / L values ​​are not exhaustively listed here due to space limitations and for the sake of brevity.

[0046] In this application, by optimizing the cation concentration in the ion solution, the intercalated ions can achieve a suitable loading and active site distribution within the montmorillonite interlayer, thereby resulting in a superior catalytic effect for the ion-intercalated montmorillonite membrane catalyst. Simultaneously, while maintaining low economic cost, it avoids ion release, preventing spillover pollution and cost waste. At low concentrations, the cation content in the intercalated montmorillonite membrane catalyst is insufficient, resulting in insufficient binding sites with the oxidant and poor catalytic efficiency. This leads to a deterioration in the oxidative degradation of phenolic compounds within the two-dimensional confined channel, thus inhibiting the reaction kinetics of phenolic compounds within the channel. At high concentrations, the catalytic efficiency no longer shows significant improvement, and economic costs increase. Furthermore, excessively high ion solution concentrations easily cause cation spillover, flowing out with the mobile phase, resulting in secondary pollution, and the presence of released ions increases the cost of subsequent treatment.

[0047] In some embodiments, the ionic solution treatment in step (2) includes immersion.

[0048] In some embodiments, the treatment time of the ion solution in step (2) is 6-48 h, for example, it can be 6 h, 10 h, 15 h, 20 h, 25 h, 30 h, 35 h, 40 h, 44 h or 48 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0049] In some embodiments, the ionic solution treatment in step (2) further includes a cleaning step.

[0050] In some embodiments, the cleaning method includes rinsing the membrane treated with the ionic solution with water 1 to 3 times, for example, once, twice or three times.

[0051] In some embodiments, the temperature of the heat treatment in step (2) is 30-120°C, for example, it can be 30°C, 40°C, 50°C, 60°C, 65°C, 70°C, 75°C, 80°C, 90°C, 100°C or 120°C, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0052] In some embodiments, the temperature of the heat treatment in step (2) is 60-80°C, for example, it can be 60°C, 62°C, 65°C, 68°C, 70°C, 72°C, 75°C, 78°C or 80°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0053] In this application, by optimizing the heat treatment temperature, free water between membrane layers can be effectively removed, thereby reducing the interlayer spacing, making the membrane structure more regular, and thus improving its catalytic effect. When the heat treatment temperature is too low, free water cannot be completely removed, and the catalytic effect deteriorates; when the heat treatment temperature is too high, the crystal structure of montmorillonite will be destroyed, thus affecting the catalytic effect.

[0054] In some embodiments, the heat treatment time in step (2) is 12-36 h, for example, it can be 12 h, 15 h, 18 h, 20 h, 22 h, 25 h, 27 h, 30 h, 33 h or 36 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0055] In some embodiments, the heat treatment time in step (2) is 24-30 h, for example, it can be 24 h, 25 h, 26 h, 27 h, 28 h, 29 h or 30 h, and specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0056] In some embodiments, the preparation method of the ion-intercalated montmorillonite membrane catalytic material specifically includes the following steps: (1) Sonicate and / or stir montmorillonite with solvent for 1-20 h, and after freezing-heating cycle, centrifuge to collect the supernatant to obtain a montmorillonite nanosheet dispersion with a concentration of 0.5-10 mg / mL; wherein, the freezing temperature in the freezing-heating cycle is -78℃~0℃ and the time is 1-48 h; the heating temperature in the freezing-heating cycle is 25-90℃ and the time is 1-24 h; the number of freezing-heating cycles is 1-5 times; between two adjacent freezing-heating cycles, there is also a dispersion step of stirring at 20-30℃ for 1-144 h; The montmorillonite nanosheet dispersion was diluted with solvent to a ratio of 3-5 times, and then vacuum filtered under a relative vacuum of -0.6 to -0.9 atm until the solvent was dried to obtain an initial membrane. After vacuum filtration under a relative vacuum of -0.6 to -0.9 atm for 10-16 h, a vacuum-assisted assembly process was performed to obtain a two-dimensional montmorillonite membrane. (2) The montmorillonite two-dimensional membrane described in step (1) is subjected to a cation concentration of 10 -5 -10 -1 The montmorillonite membrane catalyst with ion intercalation is obtained by soaking in a mol / L ion solution for 6-48 h, rinsing with water 1-3 times, and then heat-treating at 30-120℃ for 12-36 h.

[0057] Secondly, this application provides a montmorillonite membrane catalyst with ion intercalation prepared by the preparation method of the montmorillonite membrane catalyst with ion intercalation as described in the first aspect.

[0058] In some embodiments, the thickness of the ion-intercalated montmorillonite membrane catalyst is 2-10 μm, and the interlayer spacing is 12-16 Å. The 2-10 μm can be, for example, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm; the 12-16 Å can be, for example, 12 Å, 12.5 Å, 13 Å, 13.5 Å, 14 Å, 14.5 Å, 15 Å, 15.5 Å, or 16 Å, as well as specific values ​​between these ranges. Due to space limitations and for the sake of brevity, this application will not exhaustively list all the specific values ​​included in the range.

[0059] Thirdly, this application provides a flow membrane reactor comprising a montmorillonite membrane catalyst material with ion intercalation as described in the second aspect.

[0060] Fourthly, this application provides a method for the oxidative degradation of phenolic compounds, the method comprising the following steps: A membrane reaction solution is obtained by mixing phenolic compounds and aqueous solutions of oxidants. Driven by a pressure difference, the membrane reaction solution is passed through a flow membrane reactor as described in the third aspect for a flow oxidative degradation reaction.

[0061] In some embodiments, the phenolic compound includes any one or a combination of at least two of phenol, cresol, nitrophenol, chlorophenol, or hydroquinone.

[0062] In some embodiments, the aqueous oxidant includes an aqueous solution of hydrogen peroxide and / or an aqueous solution of tert-butyl hydrogen peroxide.

[0063] In some embodiments, the concentration of the oxidant aqueous solution is 0.1-2 mol / L, for example, it can be 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 1 mol / L, 1.5 mol / L or 2 mol / L, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0064] In some embodiments, the concentration of the oxidant aqueous solution is 0.2-0.6 mol / L, for example, it can be 0.2 mol / L, 0.25 mol / L, 0.3 mol / L, 0.35 mol / L, 0.4 mol / L, 0.45 mol / L, 0.5 mol / L, 0.55 mol / L, or 0.6 mol / L, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0065] In some embodiments, the molar ratio of the phenolic compound to the oxidant in the aqueous oxidant solution is 1:(1-100), where (1-100) can be, for example, 1, 3, 5, 8, 10, 20, 30, 40, 50, 80 or 100, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0066] In some embodiments, the molar ratio of the phenolic compound to the oxidant in the aqueous oxidant solution is 1:(1-30), where (1-30) can be, for example, 1, 5, 10, 15, 20, 25 or 30, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0067] In some embodiments, the molar ratio of the phenolic compound to the oxidant in the aqueous oxidant solution is 1:(1-10), where (1-10) can be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0068] In some embodiments, the pressure difference is ≥0.65 atm, for example, it can be 0.65 atm, 0.68 atm, 0.7 atm, 0.75 atm, 0.8 atm, 0.82 atm, 0.85 atm, 0.88 atm or 0.9 atm, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0069] In some embodiments, the temperature of the flow oxidation degradation reaction is 20-35°C, and the time is ≤50 s. The temperature can be, for example, 20°C, 22°C, 24°C, 25°C, 26°C, 28°C, 30°C, 32°C, 34°C, or 35°C, and the time can be, for example, 5 s, 10 s, 15 s, 20 s, 25 s, 30 s, 35 s, 40 s, 42 s, 45 s, or 50 s, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0070] In some embodiments, the pretreatment solution is pretreated by passing it through the flow membrane reactor under pressure differential before the membrane reaction solution passes through the flow membrane reactor.

[0071] The pretreatment process removes air from the flow membrane reactor, which is then introduced into the permeate reaction solution, thus affecting the catalytic efficiency.

[0072] In some embodiments, the pressure difference in the pretreatment is ≥0.65 atm, for example, it can be 0.65 atm, 0.68 atm, 0.7 atm, 0.75 atm, 0.8 atm, 0.82 atm, 0.85 atm, 0.88 atm or 0.9 atm, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0073] In some embodiments, the pretreatment solution comprises water or an aqueous solution of an oxidant.

[0074] In some embodiments, the volume ratio of the pretreatment solution to the membrane reaction solution is 1:(10-40), where (10-40) can be, for example, 10, 15, 20, 25, 30, 35 or 40, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific values ​​included in the range.

[0075] Compared with the prior art, this application has at least the following beneficial effects: (1) The preparation method provided in this application is simple and convenient and the raw materials are readily available. The synthesized montmorillonite nanosheets are vacuum-formed and then regularly stacked under negative pressure to form a montmorillonite membrane with uniform two-dimensional channels. Then, through ion solution treatment, the enrichment effect of the two-dimensional channels is utilized to achieve the purpose of ion insertion into the two-dimensional interlayer channels of montmorillonite. Finally, after heat treatment, a montmorillonite membrane catalytic material with ion intercalation with excellent catalytic effect on the oxidative degradation reaction of phenolic compounds is obtained.

[0076] (2) The flow membrane reactor provided in this application, which uses montmorillonite membrane catalyst with ion intercalation, can achieve dynamic catalysis of oxidative degradation of phenolic compounds through continuous phase cascade reaction. This enables phenolic compounds to achieve rapid (≤50 s) and efficient (conversion rate ≥45%, up to 90%) oxidative degradation at room temperature. It is suitable for the oxidative degradation of phenolic compounds with different reactivity and molecular weight, effectively solving the problem of low efficiency and high cost of existing static batch treatment of phenolic compounds, and thus well meeting the demand for efficient and low-cost treatment of phenolic industrial wastewater. Attached Figure Description

[0077] Figure 1 An atomic force microscope image of the montmorillonite nanosheets in the montmorillonite nanosheet dispersion obtained in Example 1. Figure 2 This is an atomic force microscopy height curve of montmorillonite nanosheets in the montmorillonite nanosheet dispersion obtained in Example 1; Figure 3 The X-ray diffraction pattern of montmorillonite nanosheet powder after drying the montmorillonite nanosheet dispersion obtained in Example 1 is shown. Figure 4 The X-ray diffraction pattern of the montmorillonite two-dimensional film obtained in Example 1; Figure 5 The X-ray diffraction pattern of the montmorillonite membrane catalyst with ion intercalation obtained in Example 1 is shown below. Figure 6 A scanning electron microscope cross-sectional view of the montmorillonite membrane catalytic material with ion intercalation obtained in Example 1; Figure 7 The structural assembly diagram of the flow membrane reactor provided in this application is shown; wherein: 1-filter cup, 2-montmorillonite membrane catalyst material with ion intercalation, 3-filter element, 4-filter bottle, 5-pressure difference; Figure 8 This is the liquid chromatography elution chromatogram of phenol in Example 1; Figure 9 This is a liquid chromatography elution diagram of the product after the mobile oxidation degradation of phenol in Example 1. Detailed Implementation

[0078] To facilitate understanding of this application, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of this application.

[0079] Unless otherwise specified, the materials and equipment involved in the following detailed embodiments are all conventional materials and equipment in the art and will not affect the technical effects of this application. Unless otherwise specified, the reagents and raw materials in the following examples and comparative examples are all commercially available products. Some raw material and equipment information is shown below: Montmorillonite powder: purchased from San Ding Technology, grade SD1014; Atomic force microscope: Manufacturer: Bruker; Model: Dimension Icon; X-ray diffractometer: Manufacturer: Rigaku, Model: SmartLab; Scanning electron microscope: Manufacturer: Thermo Fisher Scientific; Model: Quattro S; Liquid chromatograph: Manufacturer: Shimadzu, Model: LC-40B.

[0080] Example 1 This embodiment provides a montmorillonite membrane catalytic material with ion intercalation and its preparation method, the preparation method comprising the following steps: (1) Add 200 mg of montmorillonite powder to 200 mL of deionized water, sonicate at 500 W for 2 min, stir for 12 h to mix evenly, freeze at -20℃ for 12 h, then heat to 80℃ and keep warm for 3 h, then stir at 25℃ for 3 h, repeat the freeze-heat cycle once, then centrifuge (centrifuge speed of 4000 rpm) and collect the supernatant to obtain montmorillonite nanosheet dispersion (MMT dispersion). The MMT dispersion was tested using atomic force microscopy, and its morphology and height curves are shown in the figures below. Figure 1 and Figure 2 As shown in the figure, the montmorillonite nanosheets are few-layered montmorillonite nanosheets with a diameter > 60 nm and a thickness of 1.2 nm. X-ray diffraction analysis was performed on the montmorillonite nanosheet powder obtained after drying the MMT dispersion, and the results are as follows. Figure 3 As shown in the figure, montmorillonite nanosheets exhibit good crystallinity. Take 30 mL of the MMT dispersion and dilute it with deionized water to 4 times. Then, vacuum filter it under a relative vacuum of -0.9 atm until the deionized water is dried to obtain the initial membrane. Without disassembling the filtration device, vacuum filter it directly under this state (relative vacuum of -0.9 atm) for 12 h and perform vacuum-assisted assembly to obtain the montmorillonite two-dimensional membrane. X-ray diffraction testing was performed on the montmorillonite two-dimensional film, and the test results are as follows: Figure 4 As shown in the figure, the interlayer spacing of the montmorillonite two-dimensional film is 15.14 Å. (2) The montmorillonite two-dimensional film described in step (1) is subjected to 10 -3 The montmorillonite membrane catalyst (MMT-Fe) with ion intercalation was soaked in a mol / L FeCl3 solution for 24 h, rinsed twice with water, and then transferred to an oven for heat treatment at 80 °C for 24 h to obtain the montmorillonite membrane catalyst with ion intercalation (MMT-Fe).3+ membrane).

[0081] For the MMT-Fe 3+ The membrane was subjected to X-ray diffraction testing, and the test results are as follows: Figure 5 As shown in the figure, the MMT-Fe 3+ The interlayer spacing of the membrane was 14.18 Å; the MMT-Fe was examined using a scanning electron microscope. 3+ The cross-sectional thickness of the membrane is measured, such as... Figure 6 As shown, MMT-Fe 3+ The membrane has a cross-sectional thickness of 3.4 μm.

[0082] This embodiment provides a flow membrane reactor, the flow membrane reactor comprising a sealed MMT-Fe 3+ Microfiltration device for membranes (channel cross-sectional area 78.5 mm) 2 ), which is in accordance with Figure 7 The structure is assembled from the provided assembly diagram.

[0083] This embodiment provides a method for the oxidative degradation of phenolic compounds, the method comprising the following steps: The membrane reaction solution was obtained by mixing 188 mg of phenol and 10 mL of 0.2 mol / L hydrogen peroxide solution. The flow membrane reactor was fixed on an iron stand. 200 µL of 0.2 mol / L hydrogen peroxide solution was added to a graduated cylinder above it. The hydrogen peroxide solution was pretreated by passing through the flow membrane reactor under a pressure difference (0.8 atm). Then, 5 mL of the membrane reaction solution was added. Under the same pressure difference (0.8 atm), the membrane reaction solution passed through the MMT-Fe... 3+ The membrane has a two-dimensional confined channel in which reactants undergo a flowing oxidative degradation reaction, and the products flow out of the system with the mobile phase.

[0084] In this embodiment, the liquid chromatography elution chromatogram of phenol is as follows: Figure 8 As shown, the liquid chromatography elution chromatogram of the products after the mobile oxidation degradation of phenol is as follows. Figure 9 As shown, this indicates the presence of MMT-Fe. 3+ Membrane flow reactors can achieve rapid oxidative degradation of phenol.

[0085] Example 2 This embodiment provides a montmorillonite membrane catalytic material with ion intercalation and its preparation method, the preparation method comprising the following steps: (1) Add 200 mg of montmorillonite powder to 400 mL of deionized water, sonicate at 200 W for 5 min, stir for 15 h to mix evenly, freeze at -10℃ for 24 h, then heat to 60℃ and keep warm for 10 h, then stir at 20℃ for 20 h. Repeat this freeze-heat cycle 3 times, then centrifuge (centrifuge speed of 4000 rpm) and collect the supernatant to obtain montmorillonite nanosheet dispersion (MMT dispersion). Take 30 mL of the MMT dispersion and dilute it with deionized water to 3 times. Then, vacuum filter it under a relative vacuum of -0.8 atm until the deionized water is dried to obtain the initial membrane. Without disassembling the filtration device, vacuum filter it directly under this state (relative vacuum of -0.8 atm) for 14 h and perform vacuum-assisted assembly to obtain the montmorillonite two-dimensional membrane. (2) The montmorillonite two-dimensional film described in step (1) is subjected to 10 -2 The montmorillonite membrane catalyst (MMT-NiCl2) was soaked in a mol / L NiCl2 solution for 48 h, rinsed three times with water, and then transferred to an oven for heat treatment at 60 °C for 30 h to obtain the ion-intercalated montmorillonite membrane catalyst. 2+ (membrane). For the MMT-Ni 2+ X-ray diffraction analysis of the film revealed an interlayer spacing of 14.35 Å; scanning electron microscopy was used to analyze the MMT-Ni... 2+ The cross-sectional thickness of the membrane was measured and found to be 3.4 μm.

[0086] This embodiment provides a flow membrane reactor, the flow membrane reactor comprising a sealed MMT-Ni 2+ Microfiltration device for membranes (channel cross-sectional area 78.5 mm) 2 ), which is in accordance with Figure 7 The structure is assembled from the provided assembly diagram.

[0087] This embodiment provides a method for the oxidative degradation of phenolic compounds, the method comprising the following steps: The membrane reaction solution was obtained by mixing 188 mg of phenol and 25 mL of 0.4 mol / L tert-butyl hydrogen peroxide solution. The flow membrane reactor was fixed on an iron stand. 500 µL of 0.4 mol / L tert-butyl hydrogen peroxide solution was added to a graduated cylinder above it. The hydrogen peroxide solution was pretreated by passing through the flow membrane reactor under a pressure difference (0.65 atm). Then, 5 mL of the membrane reaction solution was added. Under the same pressure difference (0.65 atm), the membrane reaction solution passed through the MMT-Ni... 2+The membrane has a two-dimensional confined channel in which reactants undergo a flowing oxidative degradation reaction, and the products flow out of the system with the mobile phase.

[0088] Example 3 This embodiment provides a montmorillonite membrane catalytic material with ion intercalation and its preparation method, the preparation method comprising the following steps: (1) Add 200 mg of montmorillonite powder to 100 mL of deionized water, sonicate at 800 W for 1 min, stir for 10 h to mix evenly, freeze at -45℃ for 6 h, then heat to 90℃ and keep warm for 1 h, then stir at 30℃ for 1 h, repeat the freeze-heat cycle once, then centrifuge (centrifuge speed of 4000 rpm) and collect the supernatant to obtain montmorillonite nanosheet dispersion (MMT dispersion). Take 30 mL of the MMT dispersion and dilute it with deionized water to 5 times. Then, vacuum filter it under a relative vacuum of -0.7 atm until the deionized water is dried to obtain the initial membrane. Without disassembling the filtration device, vacuum filter it directly under this state (relative vacuum of -0.7 atm) for 16 h and perform vacuum-assisted assembly to obtain the montmorillonite two-dimensional membrane. (2) The montmorillonite two-dimensional film described in step (1) is subjected to 10 -2 The montmorillonite membrane catalyst (MMT-Co) with ion intercalation was soaked in a mol / L CoCl2 solution for 6 h, rinsed once with water, and then transferred to an oven for heat treatment at 70 °C for 26 h to obtain the montmorillonite membrane catalyst with ion intercalation (MMT-Co). 2+ (Membrane). Regarding the MMT-Co 2+ X-ray diffraction analysis of the membrane revealed an interlayer spacing of 14.47 Å; scanning electron microscopy was used to analyze the MMT-Co... 2+ The cross-sectional thickness of the membrane was measured and found to be 3.3 μm.

[0089] This embodiment provides a flow membrane reactor, the flow membrane reactor comprising a sealed MMT-Co 2+ Microfiltration device for membranes (channel cross-sectional area 78.5 mm) 2 ), which is in accordance with Figure 7 The structure is assembled from the provided assembly diagram.

[0090] This embodiment provides a method for the oxidative degradation of phenolic compounds, the method comprising the following steps: The membrane reaction solution was obtained by mixing 188 mg of phenol and 30 mL of 0.6 mol / L hydrogen peroxide solution. The flow membrane reactor was fixed on an iron stand. 125 µL of 0.6 mol / L hydrogen peroxide solution was added to a graduated cylinder above it. The hydrogen peroxide solution was pretreated by passing through the flow membrane reactor under a pressure difference (0.9 atm). Then, 5 mL of the membrane reaction solution was added. Under the same pressure difference (0.9 atm), the membrane reaction solution passed through the MMT-Co... 2+ The membrane has a two-dimensional confined channel in which reactants undergo a flowing oxidative degradation reaction, and the products flow out of the system with the mobile phase.

[0091] Example 4 This embodiment provides a method for oxidative degradation of phenolic compounds. The only difference between this method and Example 1 is that 188 mg of phenol is replaced with 216 mg of p-cresol. All other raw materials, contents, and operating methods are the same as in Example 1.

[0092] Example 5 This embodiment provides a method for oxidative degradation of phenolic compounds. The only difference between this method and Example 1 is that 188 mg of phenol is replaced with 278 mg of p-nitrophenol. All other raw materials, contents, and operating methods are the same as in Example 1.

[0093] Example 6 This embodiment provides a montmorillonite membrane catalytic material with ion intercalation and its preparation method. The difference between this embodiment and Example 1 is that the concentration of the FeCl3 solution in step (2) is changed from 10... -3 Adjust mol / L to 10 -2 The montmorillonite membrane catalytic material with ion intercalation was obtained by using the same raw materials, contents, and preparation methods as in Example 1, with a concentration of mol / L.

[0094] This embodiment provides a flow membrane reactor, which includes a microfiltration device (channel cross-sectional area of ​​78.5 mm) sealed with ion-intercalated montmorillonite membrane catalyst material prepared in this embodiment. 2 ), which is in accordance with Figure 7 The structure is assembled from the provided assembly diagram.

[0095] This embodiment provides a method for oxidative degradation of phenolic compounds, which differs from Example 1 only in that the method uses the flow membrane reactor of this embodiment.

[0096] Example 7 This embodiment provides a montmorillonite membrane catalytic material with ion intercalation and its preparation method. The difference between this embodiment and Example 1 is that the concentration of the FeCl3 solution in step (2) is changed from 10... -3 Adjust mol / L to 10-1 The montmorillonite membrane catalytic material with ion intercalation was obtained by using the same raw materials, contents, and preparation methods as in Example 1, with a concentration of mol / L.

[0097] This embodiment provides a flow membrane reactor, which includes a microfiltration device (channel cross-sectional area of ​​78.5 mm) sealed with ion-intercalated montmorillonite membrane catalyst material prepared in this embodiment. 2 ), which is in accordance with Figure 7 The structure is assembled from the provided assembly diagram.

[0098] This embodiment provides a method for oxidative degradation of phenolic compounds, which differs from Embodiment 1 in that the method uses the flow membrane reactor described in this embodiment.

[0099] Example 8 This embodiment provides a montmorillonite membrane catalytic material with ion intercalation and its preparation method. The difference between this embodiment and Example 1 is that the concentration of the FeCl3 solution in step (2) is changed from 10... -3 Adjust mol / L to 10 -4 The montmorillonite membrane catalytic material with ion intercalation was obtained by using the same raw materials, contents, and preparation methods as in Example 1, with a concentration of mol / L.

[0100] This embodiment provides a flow membrane reactor, which includes a microfiltration device (channel cross-sectional area of ​​78.5 mm) sealed with ion-intercalated montmorillonite membrane catalyst material prepared in this embodiment. 2 ), which is in accordance with Figure 7 The structure is assembled from the provided assembly diagram.

[0101] This embodiment provides a method for oxidative degradation of phenolic compounds, which differs from Embodiment 1 in that the method uses the flow membrane reactor described in this embodiment.

[0102] Example 9 This embodiment provides a montmorillonite membrane catalytic material with ion intercalation and its preparation method. The difference between this embodiment and Example 1 is that the concentration of the FeCl3 solution in step (2) is changed from 10... -3 Adjust mol / L to 10 -5 The montmorillonite membrane catalytic material with ion intercalation was obtained by using the same raw materials, contents, and preparation methods as in Example 1, with a concentration of mol / L.

[0103] This embodiment provides a flow membrane reactor, which includes a microfiltration device (channel cross-sectional area of ​​78.5 mm) sealed with ion-intercalated montmorillonite membrane catalyst material prepared in this embodiment.2 ), which is in accordance with Figure 7 The structure is assembled from the provided assembly diagram.

[0104] This embodiment provides a method for oxidative degradation of phenolic compounds, which differs from Embodiment 1 in that the method uses the flow membrane reactor described in this embodiment.

[0105] Example 10 This embodiment provides an ion-intercalated montmorillonite membrane catalytic material and its preparation method. The difference between this embodiment and Example 1 is that the FeCl3 solution in step (2) is adjusted to an equimolar concentration of FeCl2 solution. All other raw materials, contents, and preparation methods are the same as in Example 1, resulting in the ion-intercalated montmorillonite membrane catalytic material (MMT-FeCl2). 2+ membrane).

[0106] This embodiment provides a flow membrane reactor, which includes a microfiltration device (channel cross-sectional area of ​​78.5 mm) sealed with ion-intercalated montmorillonite membrane catalyst material prepared in this embodiment. 2 ), which is in accordance with Figure 7 The structure is assembled from the provided assembly diagram.

[0107] This embodiment provides a method for oxidative degradation of phenolic compounds, which differs from Embodiment 1 in that the method uses the flow membrane reactor described in this embodiment.

[0108] Example 11 This embodiment provides a montmorillonite membrane catalytic material with ion intercalation and its preparation method. The difference between this embodiment and Embodiment 1 is that the temperature of the heat treatment in step (2) is adjusted from 80°C to 90°C. Other raw materials, contents and preparation methods are the same as in Embodiment 1, and the montmorillonite membrane catalytic material with ion intercalation is obtained.

[0109] This embodiment provides a flow membrane reactor, which includes a microfiltration device (channel cross-sectional area of ​​78.5 mm) sealed with ion-intercalated montmorillonite membrane catalyst material prepared in this embodiment. 2 ), which is in accordance with Figure 7 The structure is assembled from the provided assembly diagram.

[0110] This embodiment provides a method for oxidative degradation of phenolic compounds, which differs from Embodiment 1 in that the method uses the flow membrane reactor described in this embodiment.

[0111] Example 12 This embodiment provides a montmorillonite membrane catalytic material with ion intercalation and its preparation method. The difference between this embodiment and Embodiment 1 is that the temperature of the heat treatment in step (2) is adjusted from 80°C to 50°C and the time is adjusted from 24 h to 36 h. Other raw materials, contents and preparation methods are the same as in Embodiment 1, and the montmorillonite membrane catalytic material with ion intercalation is obtained.

[0112] This embodiment provides a flow membrane reactor, which includes a microfiltration device (channel cross-sectional area of ​​78.5 mm) sealed with ion-intercalated montmorillonite membrane catalyst material prepared in this embodiment. 2 ), which is in accordance with Figure 7 The structure is assembled from the provided assembly diagram.

[0113] This embodiment provides a method for oxidative degradation of phenolic compounds, which differs from Embodiment 1 in that the method uses the flow membrane reactor described in this embodiment.

[0114] Comparative Example 1 This comparative example provides a method for the oxidative degradation of phenolic compounds, the method comprising the following steps: The membrane reaction solution was obtained by mixing 188 mg of phenol and 10 mL of 0.2 mol / L hydrogen peroxide solution. The montmorillonite membrane catalytic material with ion intercalation (Example 1) was ball-milled at 100 r / min for 10 min to obtain a powder catalytic material with a particle size of 200-600 nm. 1 mL of the membrane reaction solution and 3.0 mg of the powdered catalyst were reacted at 30 °C for 60 s.

[0115] Comparative Example 2 This comparative example provides a method for the oxidative degradation of phenolic compounds. The only difference between this method and Comparative Example 1 is that 188 mg of phenol is replaced with 216 mg of p-cresol. All other raw materials, contents, and operating methods are the same as those in Comparative Example 1.

[0116] Comparative Example 3 This comparative example provides a method for the oxidative degradation of phenolic compounds. The only difference between this method and Comparative Example 1 is that 188 mg of phenol is replaced with 278 mg of p-nitrophenol. All other raw materials, contents, and operating methods are the same as those in Comparative Example 1.

[0117] Comparative Example 4 This comparative example provides a method for the oxidative degradation of phenolic compounds, the method comprising the following steps: The membrane reaction solution was obtained by mixing 188 mg of phenol and 10 mL of 0.2 mol / L hydrogen peroxide solution. 1 mL of the membrane reaction solution and 3.0 mg of ferrous chloride (Aladdin-I106504) were reacted at 30 °C for 60 s.

[0118] The flux and residence time of molecules in the membrane were calculated for the different monomer reaction solutions in Examples 1-12, and the calculation formulas are as follows: A = D 2 Equation 1: ×π / 4; In Equation 1, A is the cross-sectional area of ​​the channel in the microfiltration device, and D is the diameter of the filter cup above the membrane. In the standard experiment, D = 10 mm, resulting in A = 78.5 mm. 2 .

[0119] tR=V M / k=A×h / k Equation 2; In Equation 2, V M denoted as , where is the total volume of the ion-intercalated montmorillonite membrane catalyst used in the flow membrane reactor; h is the thickness of the ion-intercalated montmorillonite membrane catalyst; and k is the slope of the reaction solution flow rate over time. tR represents the molecular residence time, which is essentially the time required for the reaction solution to fill the total volume of the ion-intercalated montmorillonite membrane catalyst. The calculation results are shown in Table 1.

[0120] The components of the phenolic compounds obtained in Examples 1-12 and Comparative Examples 1-4 after oxidative degradation were analyzed by liquid chromatography, and the conversion rate was determined by the ratio of the characteristic peaks of the reactants to the characteristic peaks of the products. The calculation results are shown in Table 1.

[0121] Table 1 According to the test results in Table 1: (1) As can be seen from Examples 1 to 12, the montmorillonite membrane catalyst material with ion intercalation prepared in this application can rapidly oxidize and degrade phenolic compounds at room temperature (tR≤50s) when applied to a flow membrane reactor. It is suitable for the efficient oxidative degradation of phenolic compounds with different reactivity and molecular weight (conversion rate of phenolic compounds ≥45%).

[0122] (2) As can be seen from the comparison between Examples 1, 6, and 8 and Examples 7 and 9, this application achieves the effect of adjusting the concentration of cations in the ionic solution to 10. -4 -10 -2At this concentration, the catalytic effect of the ion-intercalated montmorillonite membrane catalyst material can be significantly improved, thereby achieving the purpose of rapid and efficient removal of phenolic compounds. However, below this concentration range (Example 9), the catalytic effect of the ion-intercalated montmorillonite membrane catalyst material deteriorates, and the measured conversion rate of phenolic compounds in oxidative degradation is significantly reduced. Above this concentration range (Example 7), the economic cost increases, and although the measured conversion rate of phenolic compounds in oxidative degradation increases slightly, the excessively high cation concentration in the ion-intercalated montmorillonite membrane catalyst material easily causes spillover pollution.

[0123] (3) By comparing Example 1 with Examples 11 and 12, it can be seen that by optimizing the heat treatment temperature, this application can better remove free water between membrane layers, thereby reducing the interlayer spacing, making the membrane structure more regular, and thus improving its catalytic effect. When the heat treatment temperature is higher (Example 11) / lower (Example 12), the catalytic effect of the obtained montmorillonite membrane catalytic material with ion intercalation will be worse.

[0124] (4) By comparing Examples 1-12 with Comparative Examples 1-4, it can be seen that compared with the method of reacting powder catalysts in a static reaction system in the prior art (Comparative Examples 1-4), this application can better achieve the purpose of rapid and efficient removal of phenolic compounds by using montmorillonite membrane catalyst material with ion intercalation that confines ions in the montmorillonite membrane channel to a flow membrane reactor, thereby well meeting the needs of continuous large-scale phenolic wastewater treatment.

[0125] In summary, by optimizing the selection of ionic solutions and process conditions such as heat treatment temperature in the preparation method, this application enables the obtained montmorillonite membrane catalytic material with ion intercalation to have better catalytic effect. When applied to a flow membrane reactor, it can make the time for oxidative degradation of phenolic compounds at room temperature ≤42 s, and is better suited for the oxidative degradation of phenolic compounds with different reactivity and molecular weight (the conversion rate of phenolic compounds ≥80%, and can reach more than 90%).

[0126] The above description is only a specific embodiment of this application, but the protection scope of this application is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application fall within the protection and disclosure scope of this application.

Claims

1. A method for preparing a montmorillonite membrane catalytic material with ion intercalation, characterized in that, The preparation method includes the following steps: (1) Montmorillonite nanosheet dispersion was subjected to vacuum film formation and vacuum-assisted assembly treatment in sequence to obtain a two-dimensional montmorillonite film; (2) The montmorillonite two-dimensional membrane described in step (1) is subjected to ion solution treatment and heat treatment in sequence to obtain montmorillonite membrane catalyst material with ion intercalation.

2. The method for preparing the montmorillonite membrane catalytic material with ion intercalation according to claim 1, characterized in that, The montmorillonite nanosheet dispersion in step (1) is prepared by mixing montmorillonite with a solvent and then subjecting it to a freeze-heat cycle. The solvent includes water; The mixing method includes ultrasound and / or stirring; The mixing time is 1-20 h; The concentration of montmorillonite in the system after mixing with the solvent is 0.5-10 mg / mL; The freezing-heating cycle is performed at a freezing temperature of -78℃ to 0℃ for a duration of 1-48 hours. The heating temperature in the freezing-heating cycle is 25-90℃, and the time is 1-24 h; The number of freezing-heating cycles is 1-5 times; A dispersion step is also included between two adjacent freeze-heat cycles; The dispersion method includes stirring at 20-30°C for 1-144 h; The freeze-heat cycle is followed by a centrifugation step. The montmorillonite nanosheet dispersion was obtained by collecting the supernatant through centrifugation. And / or, the minimum length of the montmorillonite nanosheets in the montmorillonite nanosheet dispersion in step (1) is ≥60 nm, and the average thickness is 1.2-5 nm.

3. The method for preparing the montmorillonite membrane catalytic material with ion intercalation according to claim 1 or 2, characterized in that, The vacuum membrane formation in step (1) includes diluting the montmorillonite nanosheet dispersion and then vacuum filtering it until the solvent is dried to obtain the initial membrane; The dilution process includes diluting the montmorillonite nanosheet dispersion with a solvent to a ratio of 3-5 times. The relative vacuum degree of the vacuum filtration is -0.6 to -0.9 atm; And / or, the relative vacuum degree of the vacuum-assisted assembly process in step (1) is -0.6 to -0.9 atm, and the time is 10-16h; And / or, the vacuum-assisted assembly process described in step (1) is vacuum filtration.

4. The method for preparing the montmorillonite membrane catalytic material with ion intercalation according to any one of claims 1-3, characterized in that, The ionic solution in step (2) is a salt solution; The cations in the ionic solution include any one or a combination of at least two of nickel ions, cobalt ions, ferric ions, or ferrous ions. The anions in the ionic solution include any one or a combination of at least two of the following: halide ions, sulfate ions, or nitrate ions. The concentration of cations in the ionic solution in step (2) is 10. -5 -10 -1 mol / L; And / or, the ionic solution treatment in step (2) may be performed by immersion; And / or, the ion solution treatment time in step (2) is 6-48 h; And / or, the ionic solution treatment in step (2) further includes a cleaning step; The cleaning method includes rinsing the membrane treated with ion solution with water 1-3 times; And / or, the heat treatment in step (2) is performed at a temperature of 30-120°C for a time of 12-36 h.

5. The method for preparing the montmorillonite membrane catalytic material with ion intercalation according to claim 4, characterized in that, The ionic solution in step (2) includes any one or a combination of at least two of the following: NiCl2 solution, CoCl2 solution, Fe2(SO4)3 solution, Fe(NO3)3 solution, FeCl3 solution, FeSO4 solution, Fe(NO3)2 solution, or FeCl2 solution; And / or, the cation concentration in the ionic solution of step (2) is 10. -4 -10 -2 mol / L; And / or, the heat treatment in step (2) is performed at a temperature of 60-80°C for a time of 24-30 h.

6. A montmorillonite membrane catalyst with ion intercalation prepared by the preparation method of the montmorillonite membrane catalyst with ion intercalation as described in any one of claims 1-5; The thickness of the montmorillonite membrane catalyst with ion intercalation is 2-10 μm, and the interlayer spacing is 12-16 Å.

7. A flow membrane reactor, characterized in that, The flow membrane reactor includes the montmorillonite membrane catalyst material with ion intercalation as described in claim 6.

8. A method for oxidative degradation of phenolic compounds, characterized in that, The method includes the following steps: A membrane reaction solution is obtained by mixing phenolic compounds and aqueous solutions of oxidants. Driven by a pressure difference, the membrane reaction solution is passed through the flow membrane reactor as described in claim 7 for a flow oxidative degradation reaction.

9. The method for oxidative degradation of phenolic compounds according to claim 8, characterized in that, The phenolic compounds include any one or a combination of at least two of phenol, cresol, nitrophenol, chlorophenol, or hydroquinone; And / or, the aqueous oxidant comprises an aqueous solution of hydrogen peroxide and / or an aqueous solution of tert-butyl hydrogen peroxide; And / or, the concentration of the aqueous oxidant solution is 0.1-2 mol / L; And / or, the molar ratio of the phenolic compound to the oxidant in the aqueous solution of the oxidant is 1:(1-100); And / or, the pressure difference is ≥0.65 atm; And / or, the temperature of the flow oxidative degradation reaction is 20-35℃ and the time is ≤50 s.

10. The method for oxidative degradation of phenolic compounds according to claim 8 or 9, characterized in that, Before the membrane reaction solution passes through the flow membrane reactor, the pretreatment solution is pretreated by passing it through the flow membrane reactor under pressure difference. The pressure difference during the pretreatment is ≥0.65 atm; The pretreatment solution includes water or an aqueous solution of an oxidant; The volume ratio of the pretreatment solution to the membrane reaction solution is 1:(10-40).

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