Enzyme-like catalytic separation membrane as well as preparation method and application thereof
By forming a polyamide catalytic active layer on the supporting base membrane and modifying the peroxide enzyme catalytic molecules, the problem that nanofiltration and reverse osmosis membranes cannot effectively remove small molecular organic matter is solved, and efficient water treatment effects and improved membrane separation performance are achieved.
Patent Information
- Application Number
- CN202510925986.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-04
- Publication Date
- 2025-09-12
AI Technical Summary
Existing nanofiltration and reverse osmosis membranes cannot effectively intercept small molecular organic matter when treating water, resulting in water safety risks and membrane pollution problems. At the same time, the catalyst stability and selectivity of the catalytic membrane are limited, affecting its application value.
By adopting enzyme-like catalytic separation membrane, forming a polyamide catalytic active layer on the supporting base membrane, and modifying it with peroxide enzyme-like catalytic active molecules, combining membrane separation technology with catalytic advanced oxidation technology, efficient removal of pollutants in water can be achieved.
It achieves a high removal rate of pollutants in water (greater than 98%), reduces the risk of membrane fouling, improves water quality safety and separation efficiency, and the preparation method is simple and low-cost.
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Figure CN120618281A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of membrane separation, and in particular relates to an enzyme-like catalytic separation membrane and a preparation method and application thereof. Background Art
[0002] Thin-film composite membranes, such as nanofiltration and reverse osmosis membranes, face numerous challenges in treating organic matter in water. Some organic compounds have a small molecular weight and can permeate the membrane, reducing membrane selectivity and threatening effluent water quality. For example, pollutants such as 1,4-dioxane and dimethylnitrosamine are not effectively retained by both nanofiltration and reverse osmosis membranes, leaving them in the effluent and posing additional health risks. While nanofiltration and reverse osmosis membranes can effectively retain large organic molecules in water, organic matter trapped on the membrane surface can cause clogging and increased flow resistance, leading to severe membrane fouling and reduced separation efficiency. Furthermore, organic matter trapped on the brine side cannot be effectively treated. For example, when using reverse osmosis membranes to concentrate high-salinity industrial wastewater, high concentrations of organic matter can remain on the brine side, unable to separate from the salt. This results in a reduced purity of the crystallized salt, making it uneconomical and potentially requiring disposal as solid waste. Therefore, the development of new functional membranes that can simultaneously separate and purify organic matter is urgently needed.
[0003] In recent years, catalytic membranes have demonstrated many unique advantages in the field of water treatment. Through the action of catalysts on the membrane surface, catalytic membranes effectively catalyze and oxidize organic matter, enhancing membrane separation performance and pollutant removal efficiency while also improving the membrane's anti-fouling properties. Furthermore, catalytic membranes complete these reactions at lower temperatures and in shorter reaction times, resulting in lower energy consumption and reduced chemical usage, significantly saving energy and offering a more environmentally friendly solution. However, catalytic membranes also have some disadvantages. First, the catalytic activity of catalytic membranes depends on the performance of the catalyst. The long-term stability and durability of the catalyst are significant issues, especially in harsh operating environments, where catalyst deactivation or contamination may occur, leading to decreased membrane performance. The selectivity and reaction rate of catalytic membranes may also be limited by the membrane structure and pore size distribution. Therefore, some membranes may not be able to effectively treat complex pollutants or maintain stable performance over extended periods of operation. Therefore, while catalytic membranes hold significant potential in many applications, further addressing issues such as catalyst stability, cost, and membrane material optimization is crucial to further enhance their application value. Summary of the Invention
[0004] In view of this, the object of the present invention is to provide an enzyme-like catalytic separation membrane and its preparation method and application. The enzyme-like catalytic separation membrane provided by the present invention has good separation function, peroxide catalytic activity and catalytic stability.
[0005] The present invention provides an enzyme-like catalytic separation membrane, comprising: a supporting base membrane, and a polyamide catalytic active layer composited on a single-side surface of the supporting base membrane; the polyamide catalytic active layer is formed by interfacial polymerization reaction between an aqueous phase solution and an oil phase solution, and then modified with peroxide-like enzyme catalytic active molecules; the aqueous phase solution contains amine monomers, the oil phase solution contains acyl chloride monomers, and the peroxide-like enzyme catalytic active molecules have N-containing groups.
[0006] Preferably, the amine monomer is one or more of m-phenylenediamine, piperazine, p-phenylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine and ethylenediamine.
[0007] Preferably, the acyl chloride monomer is one or more of trimesoyl chloride, terephthaloyl chloride and phthaloyl chloride.
[0008] Preferably, the peroxidase catalytically active molecule is one or more of hemin, hemin hydrate, hemocyanin, hemocyanin hydrate, tetrakis(4-aminophenyl)porphyrin iron, tetrakis(4-aminophenyl)porphyrin iron hydrate, tetrakis(4-aminophenyl)porphyrin copper and tetrakis(4-aminophenyl)porphyrin copper hydrate.
[0009] Preferably, the supporting base membrane is made of polysulfone, polyethersulfone or polyvinylidene fluoride.
[0010] Preferably, the average membrane pore size of the enzyme-catalyzed separation membrane is less than 0.6 nm, and the molecular weight cut-off is 200 to 400 Da.
[0011] The present invention provides a method for preparing the enzyme-like catalytic separation membrane described in the above technical solution, comprising the following steps:
[0012] a) contacting one side surface of the supporting base film with an aqueous solution to obtain a base film with an aqueous monomer attached thereto;
[0013] b) immersing the base membrane with the aqueous phase monomer attached thereto in an oil phase solution to perform interfacial polymerization to form a polyamide layer, thereby obtaining an unmodified polyamide separation membrane;
[0014] c) soaking the unmodified polyamide separation membrane in a peroxide-like enzyme catalytic active molecule solution to form a polyamide catalytic active layer, thereby obtaining an enzyme-like catalytic separation membrane.
[0015] Preferably, in step a), the content of the amine monomer in the aqueous solution is 0.2 to 4 wt%; the contact temperature is 10 to 40° C., and the contact time is 10 to 300 s;
[0016] In step b), the content of the acyl chloride monomer in the oil phase solution is 0.05-0.5 wt %; the temperature of the interfacial polymerization reaction is 10-40° C., and the time is 10-300 s.
[0017] Preferably, in step c), the content of peroxidase catalytically active molecules in the peroxidase catalytically active molecule solution is 10-100 mg / L; the soaking temperature is 10-40° C., and the soaking time is 0.1-1 h.
[0018] The present invention provides a water treatment method, wherein the separation membrane used in the water treatment process comprises the enzyme-like catalytic separation membrane described in the above technical solution or the enzyme-like catalytic separation membrane prepared by the preparation method described in the above technical solution.
[0019] Compared with the prior art, the present invention provides an enzyme-like catalytic separation membrane and its preparation method and application. The enzyme-like catalytic separation membrane provided by the present invention comprises: a supporting base membrane, and a polyamide catalytic active layer composited on a single-side surface of the supporting base membrane; the polyamide catalytic active layer is formed by interfacial polymerization of an aqueous phase solution and an oil phase solution, and then modified with peroxide-like enzyme catalytic active molecules; the aqueous phase solution contains an amine monomer, the oil phase solution contains an acyl chloride monomer, and the peroxide-like enzyme catalytic active molecule has an N-containing group. The present invention fixes molecules with peroxide-like enzyme catalytic activity on the polyamide separation membrane, giving the separation membrane peroxide catalytic properties, which can catalyze various peroxides to oxidize and remove pollutants and organic matter in water, greatly improving the safety of water. Experimental results show that the enzyme-like catalytic separation membrane provided by the present invention has a removal rate of more than 98% for pollutants in water in the presence of peroxides, and a removal rate of more than 75% for residual chemical oxygen demand in industrial wastewater.
[0020] More specifically, the technical solution provided by the present invention has at least the following beneficial effects:
[0021] 1. The present invention utilizes the reaction between the N-containing group of the peroxidase-catalyzed active molecule and the residual acyl chloride on the polyamide separation membrane, and connects the active molecule with a structure similar to the active center of the natural enzyme to the polyamide molecule, thereby giving the polyamide separation membrane catalytic activity at the molecular level.
[0022] 2. The present invention combines membrane separation technology with catalytic advanced oxidation technology. The two technologies complement each other to improve the performance of removing organic matter in water bodies, which can make up for the insufficient removal performance of separation membranes for small molecular pollutants and alleviate the problems of material pollution and membrane pollution caused by large molecular organic matter.
[0023] 3. The preparation method of the separation membrane provided by the present invention is simple, has low raw material cost, and can be produced on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.
[0025] Figure 1 Schematic diagram of the structure of the enzyme-like catalytic separation membrane provided by the present invention;
[0026] Figure 2 This is a transmission electron micrograph of a cross section of the enzyme-catalyzed separation membrane of Example 1 provided by the present invention;
[0027] Figure 3 It is a bar graph of water flux of the separation membranes of Examples 1 to 9 and Comparative Example 1 provided by the present invention;
[0028] Figure 4 It is a bar graph of the salt rejection performance of the separation membranes of Examples 1 to 9 and Comparative Example 1 provided by the present invention;
[0029] Figure 5 This is a bar graph showing the pollutant 1,4-dioxane removal performance of the separation membranes of Examples 1 to 9 and Comparative Example 1 provided by the present invention;
[0030] Figure 6 It is a bar chart showing the residual chemical oxygen demand removal effect of the separation membranes of Examples 1 to 9 and Comparative Example 1 provided by the present invention.
[0031] Attachment Figures 1-2 Marking instructions: 1 is the supporting base membrane, 2 is the polyamide catalytic active layer. DETAILED DESCRIPTION
[0032] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.
[0033] The present invention provides an enzyme-like catalytic separation membrane, comprising: a supporting base membrane, and a polyamide catalytic active layer composited on a single-side surface of the supporting base membrane; the polyamide catalytic active layer is formed by interfacial polymerization reaction between an aqueous phase solution and an oil phase solution, and then modified with peroxide-like enzyme catalytic active molecules; the aqueous phase solution contains amine monomers, the oil phase solution contains acyl chloride monomers, and the peroxide-like enzyme catalytic active molecules have N-containing groups.
[0034] In the enzyme-like catalytic separation membrane provided by the present invention, the material of the supporting base membrane includes but is not limited to polysulfone, polyethersulfone or polyvinylidene fluoride; the molecular weight cutoff of the supporting base membrane is preferably 20-200kDa, specifically 20kDa, 50kDa, 100kDa or 200kDa.
[0035] In the enzyme-catalyzed separation membrane provided by the present invention, the amine monomer in the aqueous solution has at least two N-containing groups that can participate in the interfacial polymerization reaction, and the amine monomer is preferably one or more of m-phenylenediamine, piperazine, p-phenylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine and ethylenediamine; the content of the amine monomer in the aqueous solution is preferably 0.2-4wt%, specifically 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1 wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2wt%, 2.1wt%, 2.2wt%, 2.3wt%, 2.4wt%, 2.5wt%, 2.6wt%, 2.7wt%, 2.8wt%, 2.9wt%, 3wt%, 3.1wt%, 3.2wt%, 3.3wt%, 3.4wt%, 3.5wt%, 3.6wt%, 3.7wt%, 3.8wt%, 3.9wt% or 4wt%.
[0036] In the enzyme-like catalytic separation membrane provided by the present invention, the aqueous phase solution is in contact with a single surface of the supporting base membrane. The contact temperature is preferably 10 to 40°C, specifically 10°C, 15°C, 20°C, 25°C (room temperature), 30°C, 35°C or 40°C; the contact time is preferably 10 to 300s, specifically 10s, 20s, 30s, 40s, 50s, 60s, 70s, 80s, 90s, 100s, 110s, 120s, 130s, 140s, 150s, 160s, 170s, 180s, 190s, 200s, 210s, 220s, 230s, 240s, 250s, 260s, 270s, 280s, 290s or 300s.
[0037] In the enzyme-catalyzed separation membrane provided by the present invention, the acyl chloride monomer in the oil phase solution has at least two acyl chloride groups that can participate in the interfacial polymerization reaction, and the acyl chloride monomer is preferably one or more of trimesoyl chloride, terephthaloyl chloride and phthaloyl chloride; the content of the acyl chloride monomer in the oil phase solution is preferably 0.05-0.5wt%, specifically 0.05wt%, 0.07wt%, 0.1wt%, 0.12wt%, 0.15wt%, 0.17wt%, 0.2wt%, 0.23wt%, 0.25wt%, 0.27wt%, 0.3wt%, 0.32wt%, 0.35wt%, 0.37wt%, 0.4wt%, 0.42wt%, 0.45wt%, 0.47wt% or 0.5wt%.
[0038] In the enzyme-like catalytic separation membrane provided by the present invention, the organic solvent in the oil phase solution includes, but is not limited to, one or more of n-hexane, isoparaffins and n-nonane.
[0039] In the enzyme-catalyzed separation membrane provided by the present invention, the temperature for carrying out the interfacial polymerization reaction is preferably 10-40°C, specifically 10°C, 15°C, 20°C, 25°C (room temperature), 30°C, 35°C or 40°C; the time for carrying out the interfacial polymerization reaction is preferably 10-300s, specifically 10s, 20s, 30s, 40s, 50s, 60s, 70s, 80s, 90s, 100s, 110s, 120s, 130s, 140s, 150s, 160s, 170s, 180s, 190s, 200s, 210s, 220s, 230s, 240s, 250s, 260s, 270s, 280s, 290s or 300s.
[0040] In the enzyme-catalytic separation membrane provided by the present invention, the peroxidase-catalytically active molecule is preferably one or more of hemin, hemin hydrate, hemocyanin, hemocyanin hydrate, tetrakis(4-aminophenyl)porphyrin iron, tetrakis(4-aminophenyl)porphyrin iron hydrate, tetrakis(4-aminophenyl)porphyrin copper and tetrakis(4-aminophenyl)porphyrin copper hydrate.
[0041] In the enzyme-like catalytic separation membrane provided by the present invention, the method of modifying the peroxidase catalytic active molecules is preferably to soak them in a peroxidase catalytic active molecule solution. Wherein, the content of the peroxidase catalytic active molecules in the peroxidase catalytic active molecule solution is preferably 10 to 100 mg / L, specifically 10 mg / L, 15 mg / L, 20 mg / L, 25 mg / L, 30 mg / L, 35 mg / L, 40 mg / L, 45 mg / L, 50 mg / L, 55 mg / L, 60 mg / L, 65 mg / L, 70 mg / L, 75 mg / L, 80 mg / L, g / L, 85mg / L, 90mg / L, 95mg / L or 100mg / L; the soaking temperature is preferably 10-40°C, specifically 10°C, 15°C, 20°C, 25°C (room temperature), 30°C, 35°C or 40°C; the soaking time is preferably 0.1-1h, specifically 0.1h, 0.2h, 0.3h, 0.4h, 0.5h, 0.6h, 0.7h, 0.8h, 0.9h or 1h.
[0042] In the enzyme-like catalytic separation membrane provided by the present invention, the average membrane pore size of the enzyme-like catalytic separation membrane is preferably less than 0.6 nm; and the molecular weight cut-off of the enzyme-like catalytic separation membrane is preferably 200 to 400 Da.
[0043] The present invention also provides a method for preparing an enzyme-like catalytic separation membrane, which is characterized by comprising the following steps:
[0044] a) contacting one side surface of the supporting base film with an aqueous solution to obtain a base film with an aqueous monomer attached thereto;
[0045] b) immersing the base membrane with the aqueous phase monomer attached thereto in an oil phase solution to perform interfacial polymerization to form a polyamide layer, thereby obtaining an unmodified polyamide separation membrane;
[0046] c) soaking the unmodified polyamide separation membrane in a peroxide-like enzyme catalytic active molecule solution to form a polyamide catalytic active layer, thereby obtaining an enzyme-like catalytic separation membrane.
[0047] In the preparation method provided by the present invention, in step a), the material of the supporting base membrane includes but is not limited to polysulfone, polyethersulfone or polyvinylidene fluoride.
[0048] In the preparation method provided by the present invention, in step a), the aqueous phase solution contains amine monomers and water.
[0049] In the preparation method provided by the present invention, in step a), the amine monomer in the aqueous solution has at least two N-containing groups that can participate in the interfacial polymerization reaction, and the amine monomer is preferably one or more of m-phenylenediamine, piperazine, p-phenylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine and ethylenediamine; the content of the amine monomer in the aqueous solution is preferably 0.2-4wt%, specifically 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1 .1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2wt%, 2.1wt%, 2.2wt%, 2.3wt%, 2.4wt%, 2.5wt%, 2.6wt%, 2.7wt%, 2.8wt%, 2.9wt%, 3wt%, 3.1wt%, 3.2wt%, 3.3wt%, 3.4wt%, 3.5wt%, 3.6wt%, 3.7wt%, 3.8wt%, 3.9wt% or 4wt%.
[0050] In the preparation method provided by the present invention, in step a), the contact temperature is preferably 10-40°C, specifically 10°C, 15°C, 20°C, 25°C (room temperature), 30°C, 35°C or 40°C; the contact time is preferably 10-300s, specifically 10s, 20s, 30s, 40s, 50s, 60s, 70s, 80s, 90s, 100s, 110s, 120s, 130s, 140s, 150s, 160s, 170s, 180s, 190s, 200s, 210s, 220s, 230s, 240s, 250s, 260s, 270s, 280s, 290s or 300s.
[0051] In the preparation method provided by the present invention, in step b), the oil phase solution contains acyl chloride monomers and an organic solvent.
[0052] In the preparation method provided by the present invention, in step b), the acyl chloride monomer in the oil phase solution has at least two acyl chloride groups that can participate in the interfacial polymerization reaction, and the acyl chloride monomer is preferably one or more of trimesoyl chloride, terephthaloyl chloride and phthaloyl chloride; the content of the acyl chloride monomer in the oil phase solution is preferably 0.05-0.5wt%, specifically 0.05wt%, 0.07wt%, 0.1wt%, 0.12wt%, 0.15wt%, 0.17wt%, 0.2wt%, 0.23wt%, 0.25wt%, 0.27wt%, 0.3wt%, 0.32wt%, 0.35wt%, 0.37wt%, 0.4wt%, 0.42wt%, 0.45wt%, 0.47wt% or 0.5wt%.
[0053] In the preparation method provided by the present invention, in step b), the organic solvent in the oil phase solution includes but is not limited to one or more of n-hexane, isoparaffins and n-nonane.
[0054] In the preparation method provided by the present invention, in step b), the temperature for carrying out the interfacial polymerization reaction is preferably 10-40°C, specifically 10°C, 15°C, 20°C, 25°C (room temperature), 30°C, 35°C or 40°C; the time for carrying out the interfacial polymerization reaction is preferably 10-300s, specifically 10s, 20s, 30s, 40s, 50s, 60s, 70s, 80s, 90s, 100s, 110s, 120s, 130s, 140s, 150s, 160s, 170s, 180s, 190s, 200s, 210s, 220s, 230s, 240s, 250s, 260s, 270s, 280s, 290s or 300s.
[0055] In the preparation method provided by the present invention, in step c), the peroxidase catalytically active molecule solution contains peroxidase catalytically active molecules and water.
[0056] In the preparation method provided by the present invention, in step c), the peroxidase catalytically active molecule in the peroxidase catalytically active molecule solution is preferably one or more of hemin, hemin hydrate, hemocyanin, hemocyanin hydrate, tetrakis(4-aminophenyl)porphyrin iron, tetrakis(4-aminophenyl)porphyrin iron hydrate, tetrakis(4-aminophenyl)porphyrin copper and tetrakis(4-aminophenyl)porphyrin copper hydrate; the peroxidase catalytically active molecule in the peroxidase catalytically active molecule solution is preferably one or more of hemin, hemin hydrate, hemocyanin, hemocyanin hydrate, tetrakis(4-aminophenyl)porphyrin iron hydrate, tetrakis(4-aminophenyl)porphyrin copper and tetrakis(4-aminophenyl)porphyrin copper hydrate; The content of catalytically active molecules of the substance enzyme is preferably 10-100 mg / L, specifically 10 mg / L, 15 mg / L, 20 mg / L, 25 mg / L, 30 mg / L, 35 mg / L, 40 mg / L, 45 mg / L, 50 mg / L, 55 mg / L, 60 mg / L, 65 mg / L, 70 mg / L, 75 mg / L, 80 mg / L, 85 mg / L, 90 mg / L, 95 mg / L or 100 mg / L.
[0057] In the preparation method provided by the present invention, in step c), the soaking temperature is preferably 10-40°C, specifically 10°C, 15°C, 20°C, 25°C (room temperature), 30°C, 35°C or 40°C; the soaking time is preferably 0.1-1h, specifically 0.1h, 0.2h, 0.3h, 0.4h, 0.5h, 0.6h, 0.7h, 0.8h, 0.9h or 1h.
[0058] The present invention also provides a water treatment method, wherein the separation membrane used in the water treatment process comprises the enzyme-like catalytic separation membrane described in the above technical solution or the enzyme-like catalytic separation membrane prepared by the preparation method described in the above technical solution. In the present invention, the enzyme-like catalytic separation membrane can be used to simultaneously intercept, filter, and catalytically degrade pollutants in raw water in the presence of peroxides, including but not limited to potassium permonosulfate; and organic pollutants in the raw water, including but not limited to 1,4-dioxane.
[0059] For the purpose of greater clarity, the present invention is described in detail with reference to the following examples and comparative examples.
[0060] Example 1
[0061] An enzyme-catalyzed separation membrane, the structure of which is as follows Figure 1 As shown, it includes: a supporting base membrane 1, and a polyamide catalytic active layer 2 composited on one side surface of the supporting base membrane 1; the polyamide catalytic active layer 2 is formed by interfacial polymerization reaction between an aqueous solution and an oily solution, and then modified with peroxide enzyme catalytic active molecules.
[0062] The synthesis method of the above-mentioned enzyme-catalyzed separation membrane is as follows:
[0063] Step 1: dissolving an amine monomer (piperazine) in water to obtain an aqueous solution; wherein the content of the amine monomer in the aqueous solution is 1 wt %;
[0064] Step 2: dissolving an acyl chloride monomer (trimellitoyl chloride) in an organic phase solvent (n-hexane) to obtain an oil phase solution; wherein the content of the acyl chloride monomer in the oil phase solution is 0.15 wt %;
[0065] Step 3: contacting the aqueous phase solution with one side of a supporting base membrane (material: polysulfone, molecular weight cut-off: 100 kDa) to obtain a base membrane with attached aqueous phase monomers; wherein the contact temperature is room temperature and the contact time is 120 seconds;
[0066] Step 4: Immersing the base membrane with the aqueous phase monomer attached in the oil phase solution to perform interfacial polymerization to form a polyamide layer, thereby obtaining an unmodified polyamide separation membrane; wherein the interfacial polymerization reaction is performed at room temperature for 30 seconds;
[0067] Step 5: dissolving the peroxidase catalytically active molecule (tetrakis(4-aminophenyl)porphyrin iron) in water to obtain a peroxidase catalytically active molecule solution; wherein the content of the peroxidase catalytically active molecule in the water is 100 mg / L;
[0068] Step 6: Soak the unmodified polyamide separation membrane obtained in step 4 in the peroxide enzyme catalytic active molecule solution obtained in step 5 to form a polyamide catalytic active layer to obtain an enzyme-like catalytic separation membrane; wherein the soaking temperature is room temperature and the soaking time is 0.1 h.
[0069] The cross section of the enzyme-like catalytic separation membrane prepared in this example was observed by transmission electron microscopy. Figure 2 shown.
[0070] Example 2
[0071] Refer to Example 1, the only difference is that the peroxidase catalytically active molecule used in step 5 is hemocyanin.
[0072] Example 3
[0073] Refer to Example 1, the only difference is that the peroxidase catalytically active molecule used in step 5 is tetrakis(4-aminophenyl)porphyrin copper.
[0074] Example 4
[0075] Refer to Example 1, the only difference is that the peroxidase catalytically active molecule used in step 5 is hemin.
[0076] Example 5
[0077] Refer to Example 1, the only difference is that the material of the supporting base membrane used in step 3 is polyethersulfone.
[0078] Example 6
[0079] Refer to Example 1, the only difference is that the material of the supporting base membrane used in step 3 is polyvinylidene fluoride, and the molecular weight cut-off is 200 kDa.
[0080] Example 7
[0081] Refer to Example 1, the only difference is that the amine monomer used in step 1 is m-phenylenediamine.
[0082] Example 8
[0083] Refer to Example 1, the only difference is that the amine monomer used in step 1 is triethylenetetramine.
[0084] Example 9
[0085] Refer to Example 1, the only difference is that the acyl chloride monomer used in step 2 is terephthaloyl chloride.
[0086] Comparative Example 1
[0087] A polyamide separation membrane comprises: a supporting base membrane and a polyamide layer composited on one side surface of the supporting base membrane; the polyamide catalytic layer is formed by interfacial polymerization reaction between an aqueous solution and an oily solution.
[0088] The synthesis method of the above-mentioned polyamide separation membrane is as follows:
[0089] Step 1: dissolving an amine monomer (piperazine) in water to obtain an aqueous solution; wherein the content of the amine monomer in the aqueous solution is 1 wt %;
[0090] Step 2: dissolving an acyl chloride monomer (trimellitoyl chloride) in an organic phase solvent (n-hexane) to obtain an oil phase solution; wherein the content of the acyl chloride monomer in the oil phase solution is 0.15 wt %;
[0091] Step 3: contacting the aqueous phase solution with one side of a supporting base membrane (material: polysulfone, molecular weight cut-off: 100 kDa) to obtain a base membrane with attached aqueous phase monomers; wherein the contact temperature is room temperature and the contact time is 120 seconds;
[0092] Step 4: Immerse the base membrane with the attached aqueous phase monomer in the oil phase solution to perform interfacial polymerization to form a polyamide layer, thereby obtaining a polyamide separation membrane; wherein the interfacial polymerization reaction is performed at room temperature for 30 seconds.
[0093] Performance evaluation
[0094] (1) Average membrane pore size and molecular weight cut-off
[0095] The membrane materials prepared in the above examples and comparative examples were tested for average membrane pore size and molecular weight cut-off, and the results are shown in the following table:
[0096] Average membrane pore size (nm) Molecular weight cut-off (Da) Example 1 0.42 259 Example 2 0.47 277 Example 3 0.53 311 Example 4 0.40 250 Example 5 0.51 300 Example 6 0.45 270 Example 7 0.55 320 Example 8 0.50 294 Example 9 0.48 287 Comparative Example 1 0.52 305
[0097] (2) Water flux and salt interception performance test
[0098] The water flux and salt rejection performance of the membrane materials prepared in the above embodiments and comparative examples were tested using a cross-flow nanofiltration device. The specific testing method was as follows: the membrane material was first compacted with deionized water until the flux was stable; a salt solution containing 10 mM sodium sulfate was prepared as the feed solution, and the pH was adjusted to 7.0±0.1; the feed solution was thoroughly mixed for 1 hour without applying pressure; after equilibrium, in the circulation mode, the system pressure was adjusted to 6.9 bar at 25°C and a flow rate of 60 LPH, and the water flux and salt rejection rate were tested after equilibration for 1 hour.
[0099] The test results of Examples 1 to 9 and Comparative Example 1 are as follows Figures 3 and 4 As shown. Figures 3 and 4 It can be seen that the water flux and salt rejection rate of the separation membranes of Examples 1 to 9 and Comparative Example 1 are similar, indicating that the post-immersion treatment of the peroxidase active molecules does not adversely affect the basic structure of the membrane; the separation membranes prepared in Examples 1 to 9 achieve a retention rate of more than 90% for sodium sulfate, and can achieve efficient desalination of water.
[0100] (3) Pollutant removal performance test
[0101] The pollutant removal performance of the membrane materials prepared in the above examples and comparative examples was tested using a cross-flow nanofiltration device. The specific testing method was as follows: the membrane material was first compacted with deionized water until the flux was stable; 1 mg / L 1,4-dioxane and 1 mM potassium monopersulfate complex salt were prepared as the feed solution; after equilibration, the system pressure was adjusted to 6.9 bar at 25°C and a flow rate of 60 LPH in a circulation mode, and the 1,4-dioxane removal efficiency was tested after equilibration for 1 hour.
[0102] The test results of Examples 1 to 9 and Comparative Example 1 are as follows Figure 5 As shown. Figure 5 It can be seen that the pollutant removal efficiency of Examples 1 to 9 is greatly improved compared with that of Comparative Example 1. The enzyme-like catalytic separation membrane can improve the removal efficiency of pollutants and improve water quality safety.
[0103] (4) Residual chemical oxygen demand removal performance test
[0104] The membrane materials prepared in the above examples and comparative examples were tested for their residual chemical oxygen demand removal performance using a cross-flow nanofiltration apparatus. The specific testing method was as follows: the membrane material was first compacted with deionized water until the flux was stable; 20 mM hydrogen peroxide was prepared using secondary effluent from pharmaceutical industrial wastewater as the feed solution; after equilibration, the system pressure was adjusted to 6.9 bar at 25°C and a flow rate of 60 LPH in a circulation mode, and the chemical oxygen demand removal efficiency was tested after equilibration for 1 hour.
[0105] The test results of Examples 1 to 9 and Comparative Example 1 are as follows Figure 6 As shown. Figure 6 It can be seen that the chemical oxygen demand removal efficiency of Examples 1 to 9 is greatly improved compared with that of Comparative Example 1, thereby improving water quality safety.
[0106] (5) Long-term pollutant removal stability test
[0107] The membrane materials prepared in the above examples and comparative examples were tested for their long-term pollutant removal stability using a cross-flow nanofiltration device. The specific testing method was as follows: the membrane materials were first compacted with deionized water until the flux stabilized. A feed solution of 1 mg / L 1,4-dioxane and 1 mM potassium permonosulfate was prepared. After equilibration, the system pressure was maintained at 6.9 bar at 25°C and a flow rate of 60 LPH in a circulating mode. The feed solution was replaced every 12 hours, and the 1,4-dioxane removal efficiency was tested after 240 hours of continuous operation. After 240 hours of continuous operation, the 1,4-dioxane removal efficiency of Examples 1-9 remained above 98%, demonstrating excellent long-term stability.
[0108] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.
Claims
1. An enzyme-catalyzed separation membrane, characterized in that: include: A supporting base membrane, and a polyamide catalytic active layer composited on a single side surface of the supporting base membrane; The polyamide catalytic active layer is formed by interfacial polymerization reaction between an aqueous solution and an oily solution, and then modified with peroxide enzyme catalytic active molecules; the aqueous solution contains amine monomers, the oily solution contains acyl chloride monomers, and the peroxide enzyme catalytic active molecules have N-containing groups.
2. The enzyme-like catalytic separation membrane according to claim 1, characterized in that: The amine monomer is one or more of m-phenylenediamine, piperazine, p-phenylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine and ethylenediamine.
3. The enzyme-like catalytic separation membrane according to claim 1, characterized in that: The acyl chloride monomer is one or more of trimesoyl chloride, terephthaloyl chloride and phthaloyl chloride.
4. The enzyme-like catalytic separation membrane according to claim 1, characterized in that The peroxidase catalytically active molecule is one or more of hemin, hemin hydrate, hemocyanin, hemocyanin hydrate, tetrakis(4-aminophenyl)porphyrin iron, tetrakis(4-aminophenyl)porphyrin iron hydrate, tetrakis(4-aminophenyl)porphyrin copper and tetrakis(4-aminophenyl)porphyrin copper hydrate.
5. The enzyme-like catalytic separation membrane according to claim 1, characterized in that: The material of the supporting base membrane is polysulfone, polyethersulfone or polyvinylidene fluoride.
6. The enzyme-like catalytic separation membrane according to claim 1, characterized in that: The average membrane pore diameter of the enzyme-like catalytic separation membrane is less than 0.6 nm, and the molecular weight cut-off is 200-400 Da.
7. A method for preparing an enzyme-like catalytic separation membrane according to any one of claims 1 to 6, characterized in that: The following steps are involved: a) contacting one side surface of the supporting base film with an aqueous solution to obtain a base film with an aqueous monomer attached thereto; b) immersing the base membrane with the aqueous phase monomer attached thereto in an oil phase solution to perform interfacial polymerization to form a polyamide layer, thereby obtaining an unmodified polyamide separation membrane; c) soaking the unmodified polyamide separation membrane in a peroxide-like enzyme catalytic active molecule solution to form a polyamide catalytic active layer, thereby obtaining an enzyme-like catalytic separation membrane.
8. The preparation method according to claim 7, characterized in that In step a), the content of the amine monomer in the aqueous solution is 0.2 to 4 wt %; the contact temperature is 10 to 40° C., and the contact time is 10 to 300 s; In step b), the content of the acyl chloride monomer in the oil phase solution is 0.05-0.5 wt %; the temperature of the interfacial polymerization reaction is 10-40° C., and the time is 10-300 s.
9. The preparation method according to claim 7, characterized in that In step c), the content of peroxidase catalytically active molecules in the peroxidase catalytically active molecule solution is 10-100 mg / L; the soaking temperature is 10-40° C., and the soaking time is 0.1-1 h.
10. A water treatment method, characterized in that: The separation membrane used in the water treatment process includes the enzyme-like catalytic separation membrane according to any one of claims 1 to 6 or the enzyme-like catalytic separation membrane prepared by the preparation method according to any one of claims 7 to 9.