A positively charged quaternary ammonium salt polymer catalyst and its preparation method and application

Abstract

The invention belongs to the field of water treatment, and more particularly to a positively charged quaternary ammonium salt polymer catalyst and its preparation method and application. The catalyst provided by the present invention is made of a positively charged quaternary ammonium salt precursor through polymerization and anion exchange, and the positively charged quaternary ammonium salt precursor is the reaction product of acrylate and halogenated alkane; the acrylate is one or more of dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate and 3 (dimethylamino) ethyl acrylate; the halogenated alkane is one or more of undecane bromide, dodecane bromide, tetradecane bromide, hexadecane bromide, eicosane bromide, dodecane chloride, tetradecane chloride and hexadecane chloride. The catalyst provided by the present invention has good stability and antibacterial properties, can efficiently and selectively catalyze the degradation of organic pollutants by peroxide, has important practical significance for removing wastewater rich in organic pollutants, and has a wide range of applications in water pollution control and water environment restoration.

Description

Technical Field

[0001] The invention belongs to the field of water treatment, and in particular relates to a positively charged quaternary ammonium salt polymer catalyst, a preparation method and an application thereof. Background Art

[0002] Water is an essential resource for living organisms. Global water shortages and water pollution are pressing issues. The increasing human population, coupled with the discharge of domestic sewage, contains a large amount of organic pollutants. Furthermore, industrial development, including chemical, pharmaceutical, and textile industries, has also generated a large amount of industrial wastewater containing complex organic pollutants. These pollutants are highly toxic and difficult to remove. To address this wastewater purification problem, researchers have developed a range of remediation technologies to remove organic pollutants from water, such as physical adsorption, sedimentation, and coagulation. However, these traditional methods are unable to completely mineralize these pollutants. Studies have shown that advanced oxidation processes based on peroxymonosulfate (PMS), peroxydisulfate (PDS), peracetic acid (PAA), hydrogen peroxide (H2O2), and other organic peroxides can effectively remove organic pollutants from water. Peroxides can be activated through free radical and non-radical pathways to produce oxidatively active species, such as sulfate radicals, hydroxyl radicals, and singlet oxygen.

[0003] Common methods of homogeneous activation of such oxidants include UV activation, which is to break the peroxide bond in the oxidant by UV induction to generate free radicals; thermal activation, which is to break the peroxide bond in the oxidant by heating to generate free radicals; transition metal ion activation, which is to use Co 2+ 、Mn 2+ 、Fe 2+ Homogeneous activation has the advantages of high selectivity and activity, but its disadvantages are that it is difficult to separate from the reaction system and cannot be recycled, which increases the cost of degrading organic pollutants. In addition to homogeneous catalysis, heterogeneous activation has become a hot research topic in the environmental field in recent years due to its ability to achieve efficient degradation of organic matter. Heterogeneous activation is usually a mixed reaction of a solid catalyst in a liquid state. This solid-supported catalyst is easier to separate from the system and reuse.

[0004] Traditional heterogeneous solid catalysts such as carbon-based materials, metal oxides, and metal complexes often require more complex methods to synthesize, such as physical / chemical vapor deposition and high-temperature calcination. This results in high production costs and poor performance in actual industrial applications. Summary of the Invention

[0005] In view of this, the object of the present invention is to provide a positively charged quaternary ammonium salt polymer catalyst and its preparation method and application. The catalyst provided by the present invention can be obtained by simple chemical synthesis using low-cost raw materials. The catalyst can catalytically activate peroxides to produce ketone peroxide and singlet oxygen in a short period of time to achieve efficient removal of organic pollutants in water.

[0006] The present invention provides a positively charged quaternary ammonium salt polymer catalyst, which is prepared by polymerization and anion exchange of a positively charged quaternary ammonium salt precursor, wherein the positively charged quaternary ammonium salt precursor is a reaction product of an acrylate and a halogenated alkane;

[0007] The acrylic acid ester is one or more of dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate and 3-(dimethylamino)ethyl acrylate; the halogenated alkane is one or more of bromoundecane, bromododecane, bromotetradecane, bromohexadecane, bromoeicosane, chlorododecane, chlorotetradecane and chlorohexadecane.

[0008] Preferably, the acrylic acid ester is dimethylaminoethyl acrylate and / or dimethylaminoethyl methacrylate; and the halogenated alkane is one or more of undecane bromide, dodecane bromide, tetradecane bromide and hexadecane bromide.

[0009] The present invention provides a method for preparing the positively charged quaternary ammonium salt polymer catalyst described in the above technical solution, characterized in that it comprises the following steps:

[0010] a) reacting acrylate and halogenated alkane in a solvent to obtain a positively charged quaternary ammonium salt precursor;

[0011] b) polymerizing the positively charged quaternary ammonium salt precursor to obtain a polymer;

[0012] c) performing ion exchange on the anions in the polymer to obtain a positively charged quaternary ammonium salt polymer catalyst.

[0013] Preferably, in step a), the reaction temperature is 10 to 200° C.; and the reaction time is 1 to 48 hours.

[0014] Preferably, step b) is specifically:

[0015] b1) mixing the positively charged quaternary ammonium salt precursor, water, an initiator and a cross-linking agent, and performing cross-linking polymerization under ultraviolet light to obtain a polymer; the initiator is a photoinitiator;

[0016] or,

[0017] b2) mixing the positively charged quaternary ammonium salt precursor, water, an initiator and a cross-linking agent in ethanol, heating to volatilize the ethanol and causing the mixture to undergo cross-linking polymerization to obtain a polymer; the initiator being a thermal initiator;

[0018] or,

[0019] b3) mixing the positively charged quaternary ammonium salt precursor, initiator, and catalyst in a solvent, heating to carry out addition polymerization, and then dripping the obtained polymer product solution into a low-polarity solvent to obtain a polymer; the initiator is an addition polymerization chain initiator; and the catalyst is an organic alkali metal catalyst.

[0020] Preferably, in step b1), the mass ratio of the positively charged quaternary ammonium salt precursor to water is (0.1-20):1; the mass ratio of the initiator to the cross-linking agent is 1:(0.5-2); the total mass of the initiator and the cross-linking agent accounts for 1-10wt% of the total mass of the positively charged quaternary ammonium salt precursor and water; and the cross-linking polymerization time is 0.5-5min;

[0021] In step b2), the mass ratio of the positively charged quaternary ammonium salt precursor to water is (0.1-20):1; the mass ratio of the initiator to the cross-linking agent is 1:(0.5-2); the total mass of the initiator and the cross-linking agent accounts for 1-10wt% of the total mass of the positively charged quaternary ammonium salt precursor and water; the heating temperature is 40-90° C.; and the cross-linking polymerization time is 5-30 min;

[0022] In step b3), the mass ratio of the positively charged quaternary ammonium salt precursor, the initiator and the catalyst is 1:(0.05-0.1):(0.005-0.02); the heating temperature is 30-60° C.; and the addition polymerization time is 5-60 min.

[0023] The present invention provides a method for treating organic pollutants in water, comprising the following steps:

[0024] Using positively charged quaternary ammonium salt polymer catalyst to activate peroxide to degrade organic pollutants in water;

[0025] The positively charged quaternary ammonium salt polymer catalyst is the positively charged quaternary ammonium salt polymer catalyst described in the above technical solution or the positively charged quaternary ammonium salt polymer catalyst prepared by the preparation method described in the above technical solution.

[0026] Preferably, the processing specifically includes:

[0027] A) adding the positively charged quaternary ammonium salt polymer catalyst and peroxide in water, wherein the peroxide degrades organic pollutants in the water under the activation of the positively charged quaternary ammonium salt polymer catalyst;

[0028] or,

[0029] B) firstly using the positively charged quaternary ammonium salt polymer catalyst to adsorb organic pollutants in water, and then using peroxide to degrade the adsorbed organic pollutants under the activation of the positively charged quaternary ammonium salt polymer catalyst.

[0030] Preferably, the usage ratio of the positively charged quaternary ammonium salt polymer catalyst and the peroxide is (0.05-20) g: (0.1-200) mmol.

[0031] Preferably, the pH value of the water is 4-12.

[0032] Compared to the prior art, the present invention provides a positively charged quaternary ammonium salt polymer catalyst, its preparation method, and application. The catalyst is prepared from a positively charged quaternary ammonium salt precursor through polymerization and anion exchange. The positively charged quaternary ammonium salt precursor is the reaction product of an acrylate and a halogenated alkane; the acrylate is one or more of dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, and 3-(dimethylamino)ethyl acrylate; and the halogenated alkane is one or more of undecane bromide, dodecane bromide, tetradecane bromide, hexadecane bromide, eicosane bromide, dodecane chloride, tetradecane chloride, and hexadecane chloride. The catalyst can catalyze the activation of peroxides to mineralize and degrade organic pollutants. The specific process is as follows: the catalyst reacts with peroxide to form a ketone peroxide intermediate, which further reacts with peroxide to form singlet oxygen-active species, thereby mineralizing the organic pollutants. The catalyst provided by the present invention is simultaneously connected to a carbonyl functional group and a positively charged quaternary ammonium salt functional group. The introduction of the quaternary ammonium salt functional group changes the electron cloud density of the carbonyl functional group activation site, which can strengthen the oxidizing ability of the ketone peroxide intermediate. At the same time, the positively charged quaternary ammonium salt functional group can also strengthen the adsorption of pollutants in water bodies through electrostatic adsorption forces, thereby accelerating the degradation rate of pollutants. The catalyst provided by the present invention has good stability and antibacterial properties, can efficiently and selectively catalyze the degradation of organic pollutants by peroxides, and has important practical significance for removing wastewater rich in organic pollutants from agriculture, printing and dyeing, petrochemicals, etc. Moreover, since the catalyst of the present invention is simple to produce and has low production cost, it can be produced and utilized on a large scale in industry, and has broad application prospects in water pollution control and water environment restoration. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] 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.

[0034] Figure 1is a hydrogen nuclear magnetic resonance spectrum of a positively charged quaternary ammonium salt precursor provided by an embodiment of the present invention;

[0035] Figure 2 is a total reflection Fourier transform infrared spectrum of the positively charged quaternary ammonium salt polymer catalyst before and after ion exchange provided by an embodiment of the present invention;

[0036] Figure 3 is an X-ray photoelectron spectrum of the polymer catalyst before and after ion exchange provided by an embodiment of the present invention;

[0037] Figure 4 1 is a scanning electron micrograph of a positively charged quaternary ammonium salt polymer catalyst provided in an embodiment of the present invention;

[0038] Figure 5 The degradation rate diagram of pollutants at different pH values ​​provided by the embodiment of the present invention;

[0039] Figure 6 The electron paramagnetic resonance spectrum of active species generated by the reaction of the positively charged quaternary ammonium salt polymer catalyst provided by the embodiment of the present invention with PMS. DETAILED DESCRIPTION

[0040] 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.

[0041] The invention provides a positively charged quaternary ammonium salt polymer catalyst, which is prepared by polymerizing a positively charged quaternary ammonium salt precursor and performing anion exchange.

[0042] In the catalyst provided by the present invention, the positively charged quaternary ammonium salt precursor is a reaction product of an acrylate and a halogenated alkane. The acrylate is one or more of dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate and 3-(dimethylamino)ethyl acrylate, preferably dimethylaminoethyl methacrylate and / or dimethylaminoethyl acrylate; the halogenated alkane is one or more of undecane bromide, dodecane bromide, tetradecane bromide, hexadecane bromide, eicosane bromide, dodecane chloride, tetradecane chloride and hexadecane chloride, preferably one or more of undecane bromide, dodecane bromide, tetradecane chloride and hexadecane chloride; when the reaction is carried out, The molar ratio of the acrylic acid ester to the halogenated alkane is preferably 1:(1-10), specifically 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10; the reaction temperature is preferably 10-200°C; and the reaction time is 1-48h.

[0043] In the catalyst provided by the present invention, the polymerization method is preferably cross-linking polymerization or addition polymerization; the cross-linking polymerization method is preferably photo-induced cross-linking polymerization or heat-induced cross-linking polymerization.

[0044] In the catalyst provided herein, the purpose of the anion exchange is to replace the halogen counterions in the polymer, preventing these counterions from generating halogen free radicals during water treatment, which in turn generate toxic halogenated byproducts and cause secondary water pollution. In the present invention, it is preferred to completely exchange the anions in the polymer; preferably, the anion exchange is achieved using an ion exchange resin.

[0045] The present invention also provides a method for preparing the positively charged quaternary ammonium salt polymer catalyst described in the above technical solution, comprising the following steps:

[0046] a) reacting acrylate and halogenated alkane in a solvent to obtain a positively charged quaternary ammonium salt precursor;

[0047] b) polymerizing the positively charged quaternary ammonium salt precursor to obtain a polymer;

[0048] c) performing ion exchange on the anions in the polymer to obtain a positively charged quaternary ammonium salt polymer catalyst.

[0049] In the preparation method provided by the present invention, in step a), the type selection and dosage ratio of the acrylic ester and the halogenated alkane have been introduced above and will not be repeated here; the solvent includes but is not limited to one or more of acetone, acetonitrile and tetrahydrofuran.

[0050] In the preparation method provided by the present invention, in step a), the reaction temperature is preferably 10-200°C, specifically 10°C, 20°C, 30°C, 40°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C or 200°C; the reaction time is preferably 1-48h, specifically 1h, 4h, 8h, 12h, 16h, 20h, 24h, 28h, 32h, 36h, 40h, 44h or 48h.

[0051] In the preparation method provided by the present invention, in step a), after the reaction is completed, the reaction mixture is cooled, and then a poorly polar solvent is added. At this time, a white solid precipitates from the solvent, is filtered, and dried to obtain a positively charged quaternary ammonium salt precursor.

[0052] In the preparation method provided by the present invention, in step b), the polymerization method is preferably cross-linking polymerization or addition polymerization; the cross-linking polymerization method is preferably photo-initiated cross-linking polymerization or heat-initiated cross-linking polymerization; wherein, when photo-initiated cross-linking polymerization is adopted, the initiator used is a photoinitiator; when heat-initiated cross-linking polymerization is adopted, the initiator used is a thermal initiator; when addition polymerization is adopted, the initiator used is an addition polymerization chain initiator.

[0053] In the preparation method provided by the present invention, in step b), when the polymerization method adopted is photo-induced cross-linking polymerization, the specific process includes:

[0054] b1) mixing the positively charged quaternary ammonium salt precursor, water, an initiator (photoinitiator) and a cross-linking agent, and performing cross-linking polymerization under ultraviolet light to obtain a polymer.

[0055] In the preparation method provided by the present invention, in step b1), the mass ratio of the positively charged quaternary ammonium salt precursor to water is preferably (0.1-20):1, specifically 0.1:1, 0.5:1, 1:1, 1.5:1, 1.6:1, 1.7:1, 2:1, 2.5:1, 2.7:1, 2.8:1, 3:1, 4:1, 5:1, 7:1, 10:1, 12:1, 15:1, 17:1 or 20:1.

[0056] In the preparation method provided by the present invention, in step b1), the initiator is preferably one or more of 2-hydroxy-2-methyl-1-phenylpropanone, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone and 2,2-dimethoxy-2-phenylacetophenone; the cross-linking agent is preferably one or more of butyl acrylate, ethylene glycol-dimethacrylate and 1,4-butanediol diacrylate; the mass ratio of the initiator to the cross-linking agent is preferably 1:(0.5-2), specifically 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1:2.

[0057] In the preparation method provided by the present invention, in step b1), the total mass of the initiator and the cross-linking agent preferably accounts for 1 to 10 wt% of the total mass of the positively charged quaternary ammonium salt precursor and water, and can specifically be 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt% or 10 wt%.

[0058] In the preparation method provided by the present invention, in step b1), the wavelength of the ultraviolet light is preferably 200-400 nm, specifically 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm, 310 nm, 320 nm, 330 nm, 340 nm, 350 nm, 355 nm, 360 nm, 365 nm, 370 nm, 375 nm, 380 nm, 385 nm, 390 nm, 395 nm or 400 nm; the time of the cross-linking polymerization is preferably 0.5-5 min, specifically 0.5 min, 1 min, 1.5 min, 2 min, 2.5 min, 3 min, 3.5 min, 4 min, 4.5 min or 5 min.

[0059] In the preparation method provided by the present invention, in step b), when the polymerization method adopted is heat-induced cross-linking polymerization, the specific process includes:

[0060] b2) mixing the positively charged quaternary ammonium salt precursor, water, an initiator (thermal initiator) and a cross-linking agent in ethanol, heating to volatilize the ethanol and cross-linking and polymerizing the mixture to obtain a polymer.

[0061] In the preparation method provided by the present invention, in step b2), the mass ratio of the positively charged quaternary ammonium salt precursor to water is preferably (0.1-20):1, specifically 0.1:1, 0.5:1, 1:1, 1.5:1, 1.6:1, 1.7:1, 2:1, 2.5:1, 2.7:1, 2.8:1, 3:1, 4:1, 5:1, 7:1, 10:1, 12:1, 15:1, 17:1 or 20:1.

[0062] In the preparation method provided by the present invention, in step b2), the initiator is preferably azobisisobutyronitrile and / or azobisisoheptanenitrile; the cross-linking agent is preferably one or more of butyl acrylate, ethylene glycol dimethacrylate and 1,4-butanediol diacrylate; the mass ratio of the initiator to the cross-linking agent is preferably 1:(0.5-2), specifically 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1:2.

[0063] In the preparation method provided by the present invention, in step b2), the total mass of the initiator and the cross-linking agent preferably accounts for 1 to 10 wt% of the total mass of the positively charged quaternary ammonium salt precursor and water, and can specifically be 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt% or 10 wt%.

[0064] In the preparation method provided by the present invention, in step b2), the heating temperature is preferably 40-90°C, specifically 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C; the cross-linking polymerization time is preferably 5-30 min, specifically 5 min, 7 min, 10 min, 12 min, 15 min, 17 min, 20 min, 23 min, 25 min, 27 min or 30 min.

[0065] In the preparation method provided by the present invention, in step b), when the polymerization method adopted is addition polymerization, the specific process includes:

[0066] b3) mixing the positively charged quaternary ammonium salt precursor, an initiator (addition polymerization chain initiator), and a catalyst in a solvent, heating to carry out addition polymerization, and then dropping the obtained polymer product solution into a low-polarity solvent to obtain a polymer.

[0067] In the preparation method provided by the present invention, in step b3), the initiator is an addition polymerization chain initiator, preferably dimethyl ketene methyltrimethylsilyloxy acetal or 1-methoxy-1-tri(phenyl)silyl-2-methyl-1-propylene; the mass ratio of the positively charged quaternary ammonium salt precursor to the initiator is preferably 1:(0.05-0.1), specifically 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09 or 1:0.1.

[0068] In the preparation method provided by the present invention, in step b3), the catalyst is an organic alkali metal catalyst, preferably one or more of diphenylmagnesium, phenylmagnesium bromide and phenylmagnesium chloride; the mass ratio of the positively charged quaternary ammonium salt precursor to the catalyst is preferably 1:(0.005-0.02), specifically 1:0.005, 1:0.007, 1:0.01, 1:0.012, 1:0.015, 1:0.017 or 1:0.02.

[0069] In the preparation method provided by the present invention, in step b3), the solvent includes but is not limited to tetrahydrofuran.

[0070] In the preparation method provided by the present invention, in step b3), the heating temperature is preferably 30-60°C, specifically 30°C, 35°C, 40°C, 45°C, 50°C, 55°C or 60°C; the addition polymerization time is preferably 5-60 min, specifically 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 50 min or 60 min.

[0071] In the preparation method provided by the present invention, in step b3), the low-polarity solvent includes but is not limited to petroleum ether.

[0072] In the preparation method provided by the present invention, in step c), the specific process of performing the ion exchange preferably includes:

[0073] The polymer is mixed with an ion exchange solution to perform anion exchange, and the liquid phase is removed to obtain a positively charged quaternary ammonium salt polymer catalyst.

[0074] In the above-mentioned ion exchange specific process provided by the present invention, the ion exchange solution is preferably an aqueous sodium nitrate solution; the concentration of the ion exchange solution is preferably 0.01-1 mol / L, specifically 0.01 mol / L, 0.05 mol / L, 0.1 mol / L, 0.15 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L or 1 mol / L; the mixing time is preferably 24-72 h, specifically 24 h, 28 h, 32 h, 36 h, 40 h, 44 h, 48 h, 52 h, 56 h, 60 h, 64 h, 68 h or 72 h.

[0075] The present invention also provides a method for treating organic pollutants in water, comprising the following steps:

[0076] Using positively charged quaternary ammonium salt polymer catalyst to activate peroxide to degrade organic pollutants in water;

[0077] The positively charged quaternary ammonium salt polymer catalyst is the positively charged quaternary ammonium salt polymer catalyst described in the above technical solution or the positively charged quaternary ammonium salt polymer catalyst prepared by the preparation method described in the above technical solution.

[0078] In the water treatment method provided by the present invention, the organic pollutants in the water include but are not limited to one or more of 2,4-dichlorophenol, bisphenol A, sulfamethoxazole, phenol, acetaminophen and methyl parahydroxybenzoate; the concentration of the organic pollutants in the water is preferably 10 to 100 μmol / L, specifically 10 μmol / L, 15 μmol / L, 20 μmol / L, 25 μmol / L, 30 μmol / L, 35 μmol / L, 40 μmol / L, 45 μmol / L, 50 μmol / L, 55 μmol / L, 60 μmol / L, 65 μmol / L, 70 μmol / L, 75 μmol / L, 80 μmol / L, 85 μmol / L, 90 μmol / L, 95 μmol / L or 100 μmol / L.

[0079] In the water treatment method provided by the present invention, the pH value of the water is preferably 4 to 12, specifically 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5 or 12.

[0080] In the water treatment method provided by the present invention, the peroxide is preferably one or more of hydrogen peroxide, peracetic acid, sodium peroxodisulfate, potassium peroxodisulfate, ammonium peroxodisulfate, potassium peroxomonosulfate, sodium peroxomonosulfate and ammonium peroxomonosulfate.

[0081] In the water treatment method provided by the present invention, the usage ratio of the positively charged quaternary ammonium salt polymer catalyst and the peroxide is preferably (0.05-20) g:(0.1-200) mmol, more preferably (0.05-1) g:(0.1-10) mmol, and most preferably (0.1-0.6) g:(0.5-2) mmol.

[0082] In the water treatment method provided by the present invention, the specific treatment process preferably includes:

[0083] A) adding the positively charged quaternary ammonium salt polymer catalyst and peroxide in water, wherein the peroxide degrades organic pollutants in the water under the activation of the positively charged quaternary ammonium salt polymer catalyst;

[0084] or,

[0085] B) firstly using the positively charged quaternary ammonium salt polymer catalyst to adsorb organic pollutants in water, and then using peroxide to degrade the adsorbed organic pollutants under the activation of the positively charged quaternary ammonium salt polymer catalyst.

[0086] In the water treatment method provided by the present invention, step B) can be implemented as follows:

[0087] B1) first adding the positively charged quaternary ammonium salt polymer catalyst in water, utilizing the positively charged quaternary ammonium salt polymer catalyst to adsorb the organic pollutants in water; afterwards adding peroxide in water again, the peroxide degrades the adsorbed organic pollutants under the activation of the positively charged quaternary ammonium salt polymer catalyst;

[0088] or,

[0089] B2) passing the water through a packing column filled with the positively charged quaternary ammonium polymer catalyst, and utilizing the positively charged quaternary ammonium polymer catalyst in the packing column to adsorb organic pollutants in the water; and then adding peroxide into the packing column, and degrading the adsorbed organic pollutants under the activation of the positively charged quaternary ammonium polymer catalyst by the peroxide.

[0090] In the water treatment method provided by the present invention, in step A) and step B1), the amount of the positively charged quaternary ammonium salt polymer catalyst added to the water is preferably 0.05-1 g / L, specifically 0.05 g / L, 0.1 g / L, 0.15 g / L, 0.2 g / L, 0.25 g / L, 0.3 g / L, 0.35 g / L, 0.4 g / L, 0.45 g / L, 0.5 g / L, 0.55 g / L, 0.6 g / L, 0.65 g / L, 0.7 g / L, 0.75 g / L, 0.8 g / L, 0.85 g / L, 0.9 g / L, 0.95 g / L or 1 g / L; the amount of the peroxide added to the water is preferably 0.1-50 mmol / L, specifically 0.1 mmol / L, 0.5 mmol / L, 1 mmol / L, 1.5 mmol / L, 2 mmol / L , 2.5mmol / L, 3mmol / L, 3.5mmol / L, 4mmol / L, 4.5mmol / L, 5mmol / L, 5.5mmol / L, 6mmol / L, 6.5mmol / L, 7mmol / L, 7.5mmol / L, 8mmol / L, 8.5mmol / L, 9mmol / L, 9.5mmol / L, 10mmol / L , 12mmol / L, 15mmol / L, 17mmol / L, 20mmol / L, 23mmol / L, 25mmol / L, 27mmol / L, 30mmol / L, 32mmol / L, 35mmol / L, 37mmol / L, 40mmol / L, 42mmol / L, 45mmol / L, 47mmol / L or 50mmol / L.

[0091] In the water treatment method provided by the present invention, in step B2), the amount of the peroxide added to the packing column is preferably 1 to 50 mmol / L, specifically 1 mmol / L, 3 mmol / L, 5 mmol / L, 7 mmol / L, 10 mmol / L, 12 mmol / L, 15 mmol / L, 17 mmol / L, 20 mmol / L, 23 mmol / L, 25 mmol / L, 27 mmol / L, 30 mmol / L, 32 mmol / L, 35 mmol / L, 37 mmol / L, 40 mmol / L, 42 mmol / L, 45 mmol / L, 47 mmol / L or 50 mmol / L.

[0092] The technical solution provided by the present invention has at least the following advantages:

[0093] 1) The present invention chemically synthesizes a functional polymer catalyst containing a positively charged quaternary ammonium salt and a carbonyl functional group under simple and mild reaction conditions. The catalyst reacts with peroxide to form a ketone peroxide intermediate, which further reacts with peroxide to generate singlet oxygen active species, thereby mineralizing and degrading organic pollutants.

[0094] 2) The catalyst provided by the present invention has good stability and antibacterial properties, and can efficiently and selectively catalyze the degradation of organic pollutants by peroxides, which has important practical significance for removing wastewater rich in organic pollutants from agriculture, printing and dyeing, petrochemicals, etc.;

[0095] 3) The catalyst provided by the present invention has a simple production method and low production cost, can be produced and utilized on a large scale in industry, and has broad application prospects in water pollution control and water environment restoration.

[0096] For the purpose of greater clarity, the present invention is described in detail with reference to the following examples.

[0097] Example 1

[0098] Weigh 50g of tetradecane bromide and 20g of dimethylaminoethyl methacrylate, dissolve them in 100mL of acetone solution, stir for 30min, and react at 70°C for 48h. After the reaction, add 150mL of n-hexane to precipitate a large amount of white powder. Separate the white powder with a suction filtration funnel and dry it overnight at room temperature in vacuum to obtain a positively charged quaternary ammonium salt precursor. Add 500mg of the above-mentioned positively charged quaternary ammonium salt precursor to a 1.5mL centrifuge tube, add 180mg of pure water, stir several times to mix evenly, and then add about 10 mg of the photoinitiator 2,2-dimethoxy-2-phenylacetophenone and 10 mg of the photocrosslinker ethylene glycol-dimethacrylate were heated and mixed again, taken out and spread on a glass slide, and cross-linked and polymerized under ultraviolet light (365 nm) at room temperature for 5 minutes to obtain a cross-linked polymer; the above cross-linked polymer was placed in a mortar and ground into small particles, ultrasonically dispersed in a 1M sodium nitrate aqueous solution, shaken for 48 hours, filtered, washed with distilled water, and dried to obtain a positively charged quaternary ammonium salt polymer catalyst.

[0099] 2 mM peroxymonosulfate (pollutant), 30 mg of the above-mentioned positively charged quaternary ammonium salt polymer catalyst, and 10 μM 2,4-dichlorophenol were added to 50 mL of laboratory water with a pH value of 12. Stirring was maintained throughout the water treatment process, and 100% removal of the pollutant was completed within 1 minute.

[0100] Example 2

[0101] 10 g of undecane bromide and 6 g of dimethylaminoethyl acrylate were weighed and dissolved in 100 mL of tetrahydrofuran solution. The mixture was stirred for 30 min and reacted at 50° C. for 40 h. After the reaction, 100 mL of ethyl acetate was added to precipitate a large amount of white powder, which was dried overnight at room temperature under vacuum to obtain a positively charged quaternary ammonium salt precursor. 200 mg of the positively charged quaternary ammonium salt precursor was added to a 1 mL centrifuge tube, 100 mg of pure water was added, and the mixture was stirred several times to mix uniformly. Then, about 8 mg of a photoinitiator, 2,2-dimethoxy-2-phenylacetophenone, and 6 mg of a photocrosslinker, ethylene glycol dimethacrylate, were added. The mixture was heated and mixed again, and the mixture was taken out and spread on a glass slide. The mixture was cross-linked and polymerized under ultraviolet light (365 nm) at room temperature for 2 min to obtain a cross-linked polymer. The cross-linked polymer was placed in a mortar and ground into small particles. The powder was ultrasonically dispersed in a 1 M sodium nitrate aqueous solution. The mixture was shaken for 48 h, filtered, washed with distilled water, and dried to obtain a positively charged quaternary ammonium salt polymer catalyst.

[0102] 2 mM permonosulfate, 30 mg of the above-mentioned positively charged quaternary ammonium salt polymer catalyst, and 10 μM 2,4-dichlorophenol were added to 50 mL of laboratory water with a pH value of 12. Stirring was maintained throughout the water treatment process, and 100% removal of pollutants was completed within 4 minutes.

[0103] Example 3

[0104] 10 g of tetradecane bromide and 6 g of dimethylaminoethyl methacrylate were weighed and dissolved in 150 mL of acetonitrile solution. The mixture was stirred for 25 minutes and then reacted at 65° C. for 40 hours. After the reaction, 200 mL of petroleum ether was added to precipitate a large amount of white powder, which was dried overnight at room temperature in a vacuum to obtain a positively charged quaternary ammonium salt precursor. 100 mg of the positively charged quaternary ammonium salt precursor was added to a 1 mL centrifuge tube, 60 mg of pure water was added, and the mixture was stirred several times to mix evenly. Then, about 5 mg of azobisisobutylene as a thermal initiator and 5 mg of ethylene glycol-dimethacrylate as a cross-linking agent were added, and the mixture was dissolved in ethanol and heated at 65° C. for cross-linking polymerization for 30 minutes to obtain a cross-linked polymer. The cross-linked polymer was placed in a mortar and ground into small particles. The powder was ultrasonically dispersed in a 1 M sodium nitrate aqueous solution. The powder was shaken for 48 hours, filtered, washed with distilled water, and dried to obtain a positively charged quaternary ammonium salt polymer catalyst.

[0105] 2 mM permonosulfate, 30 mg of the above-mentioned positively charged quaternary ammonium salt polymer catalyst, and 10 μM 2,4-dichlorophenol were added to 50 mL of laboratory water with a pH value of 12. Stirring was maintained throughout the water treatment process, and 100% removal of pollutants was completed within 10 minutes.

[0106] Example 4

[0107] 10 g of tetradecane bromide and 6 g of dimethylaminoethyl methacrylate were weighed and dissolved in 150 mL of acetonitrile solution. The mixture was stirred for 25 min and reacted at 65° C. for 40 h. After the reaction was completed, 200 mL of petroleum ether was added to precipitate a large amount of white powder, which was dried overnight at room temperature in a vacuum to obtain a positively charged quaternary ammonium salt precursor. 100 mg of the positively charged quaternary ammonium salt precursor, 5 mg of 1-methoxy-1-tri(phenyl)silyl-2-methyl-1-propylene, 1 mg of phenylmagnesium chloride, and 30 mL of tetrahydrofuran were added to a 100 mL flask and stirred to mix uniformly. The mixture was polymerized at 40° C. for 40 min, 5 mL of the polymer solution was taken out, and the mixture was dropwise added into 30 mL of petroleum ether. The polymer was collected and dried. The cross-linked polymer was placed in a mortar and ground into small particles. The mixture was ultrasonically dispersed in a 1 M sodium nitrate aqueous solution. After shaking for 48 h, the mixture was filtered, washed with distilled water, and dried to obtain a positively charged quaternary ammonium salt polymer catalyst.

[0108] 2 mM permonosulfate, 30 mg of the above-mentioned positively charged quaternary ammonium salt polymer catalyst and 10 μM 2,4-dichlorophenol were added to 50 mL of laboratory water with a pH value of 12. Stirring was maintained throughout the water treatment process, and 80% of the pollutants were removed within 10 minutes.

[0109] Example 5

[0110] 10 g of tetradecane bromide and 6 g of dimethylaminoethyl methacrylate were weighed and dissolved in 150 mL of acetonitrile solution. The mixture was stirred for 25 minutes and then reacted at 65° C. for 40 hours. After the reaction, 200 mL of petroleum ether was added to precipitate a large amount of white powder, which was dried overnight at room temperature in a vacuum to obtain a positively charged quaternary ammonium salt precursor. 100 mg of the positively charged quaternary ammonium salt precursor was added to a 1 mL centrifuge tube, 60 mg of pure water was added, and the mixture was stirred several times to mix evenly. Then, about 5 mg of azobisisobutylene as a thermal initiator and 5 mg of ethylene glycol-dimethacrylate as a cross-linking agent were added, and the mixture was dissolved in ethanol and heated at 65° C. for cross-linking polymerization for 30 minutes to obtain a cross-linked polymer. The cross-linked polymer was placed in a mortar and ground into small particles. The powder was ultrasonically dispersed in a 1 M sodium nitrate aqueous solution. The powder was shaken for 48 hours, filtered, washed with distilled water, and dried to obtain a positively charged quaternary ammonium salt polymer catalyst.

[0111] 50 mL of actual water (pH 8.25, conductivity 178.5 μs / cm) was added with 2 mM permonosulfate, 30 mg of the aforementioned positively charged quaternary ammonium polymer catalyst, and 10 μM 2,4-dichlorophenol. Stirring was maintained throughout the water treatment process, and 100% removal of the pollutants was achieved within 30 minutes.

[0112] Example 6

[0113] The difference between this embodiment and specific example 1 is that the organic pollutants in the degradation process are bisphenol A, sulfamethoxazole, phenol, acetaminophen or methyl paraben. The other steps and parameters are the same. At a pH of 7, bisphenol A of the same concentration is 100% removed within 10 minutes, sulfamethoxazole is 100% removed within 10 minutes, phenol is 80% removed within 15 minutes, acetaminophen is 100% removed within 12 minutes, and methyl paraben is 93% removed within 15 minutes.

[0114] Performance testing and characterization

[0115] (1) Structure and characterization of catalysts

[0116] The positively charged quaternary ammonium salt precursor prepared in Example 1 was subjected to nuclear magnetic resonance analysis: the nuclear magnetic resonance 1H spectrum data were obtained on a BrukerAVANCE AV III 400 liquid nuclear magnetic spectrometer at the Physical and Chemical Experimental Center of the University of Science and Technology of China using deuterated chloroform as solvent ( Figure 1 ): δ(ppm)6.16(s,1H),5.12(s,1H),4.63(m,2H),4.12(m,2H),3.55(m,2H) ,3.44(s,6H),1.94(s,3H),1.76(m,12H),1.23–1.36(m,23H),0.88(m,3H).

[0117] The positively charged quaternary ammonium salt polymer catalyst prepared in Example 1 was subjected to infrared spectroscopy analysis: the analysis was performed on a Thermo Scientific Nicolet 8700 at the Physical and Chemical Experiment Center of the University of Science and Technology of China, with a scanning range of 4000-400 cm -1 , the results are as follows Figure 2 shown; from Figure 2 It can be seen that the use of NO3 - Ions replace Cl - After that, at 1380cm -1 A vibration absorption peak appeared.

[0118] The positively charged quaternary ammonium salt polymer catalyst prepared in Example 1 was subjected to X-ray photoelectron spectroscopy analysis to specifically analyze the C, N, and O element contents of the catalyst: the test was performed on an ESCALAB 250Xi at the Physical and Chemical Experimental Center of the University of Science and Technology of China. The results are as follows: Figure 3 As shown; Figure 3 The data showed that after ion exchange, the catalyst had a clear NO bond peak, and the ratio of NO content to CN content was 1:1, indicating that Br - The counterion has been completely replaced by NO3 - .

[0119] The positively charged quaternary ammonium salt polymer catalyst prepared in Example 1 was subjected to scanning electron microscopy surface analysis: the surface of the catalyst was characterized using a GeminiSEM450 field emission scanning electron microscope at the Physical and Chemical Experimental Center of the University of Science and Technology of China ( Figure 4 ), when the magnification reaches 1000 times, it can be seen that the surface of the catalyst powder after grinding is smooth with a few wrinkles.

[0120] (2) Test and analysis of the degradation of the organic pollutant 2,4-dichlorophenol by the catalyst

[0121] At room temperature, 50 mL of phosphate buffer solution with different pH values ​​was prepared, 20 mg of the positively charged quaternary ammonium salt polymer catalyst prepared in Example 1 and the organic pollutant 2,4-dichlorophenol (10 μM) were added and stirred for 30 min to ensure adsorption equilibrium, and then PMS (1 mM) was added. The supernatant was filtered and tested by high performance liquid chromatography every 1 min, and the degradation rate of the pollutant was calculated based on the test results. The results are shown in FIG. Figure 5 As shown. Figure 5 It can be seen that under the alkaline condition of pH=12, the catalyst first adsorbs a large amount of pollutants (about 98%) and then begins to degrade. Within two minutes, the degradation is completely completed.

[0122] Electron paramagnetic resonance (EPR) spectrometer test found that the positively charged quaternary ammonium salt polymer catalyst prepared in Example 1 activated PMS and finally generated singlet oxygen ( Figure 6 ), as the reaction proceeds, the singlet oxygen content is gradually consumed by the decomposition of pollution.

[0123] 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. A positively charged quaternary ammonium salt polymer catalyst, characterized in that It is prepared by polymerization and anion exchange of a positively charged quaternary ammonium salt precursor, wherein the positively charged quaternary ammonium salt precursor is a reaction product of an acrylate and a halogenated alkane; The acrylic acid ester is dimethylaminoethyl acrylate and / or dimethylaminoethyl methacrylate; the halogenated alkane is one or more of undecane bromide, dodecane bromide, tetradecane bromide, hexadecane bromide, eicosane bromide, dodecane chloride, tetradecane chloride and hexadecane chloride.

2. The positively charged quaternary ammonium salt polymer catalyst according to claim 1, wherein The halogenated alkane is one or more of undecane bromide, dodecane bromide, tetradecane bromide and hexadecane bromide.

3. A method for preparing a positively charged quaternary ammonium salt polymer catalyst according to claim 1 or 2, characterized in that: The following steps are involved: a) reacting acrylate and halogenated alkane in a solvent to obtain a positively charged quaternary ammonium salt precursor; b) polymerizing the positively charged quaternary ammonium salt precursor to obtain a polymer; c) performing ion exchange on the anions in the polymer to obtain a positively charged quaternary ammonium salt polymer catalyst.

4. The preparation method according to claim 3, characterized in that In step a), the reaction temperature is 10 to 200° C.; and the reaction time is 1 to 48 hours.

5. The preparation method according to claim 3, characterized in that Step b) is specifically: b1) mixing the positively charged quaternary ammonium salt precursor, water, an initiator and a cross-linking agent, and performing cross-linking polymerization under ultraviolet light to obtain a polymer; the initiator is a photoinitiator; or, b2) mixing the positively charged quaternary ammonium salt precursor, water, an initiator and a cross-linking agent in ethanol, heating to volatilize the ethanol and causing the mixture to undergo cross-linking polymerization to obtain a polymer; the initiator being a thermal initiator; or, b3) mixing the positively charged quaternary ammonium salt precursor, initiator, and catalyst in a solvent, heating to carry out addition polymerization, and then dripping the obtained polymer product solution into a low-polarity solvent to obtain a polymer; the initiator is an addition polymerization chain initiator; and the catalyst is an organic alkali metal catalyst.

6. The preparation method according to claim 5, characterized in that In step b1), the mass ratio of the positively charged quaternary ammonium salt precursor to water is (0.1-20):1; the mass ratio of the initiator to the cross-linking agent is 1:(0.5-2); the total mass of the initiator and the cross-linking agent accounts for 1-10wt% of the total mass of the positively charged quaternary ammonium salt precursor and water; and the cross-linking polymerization time is 0.5-5min; In step b2), the mass ratio of the positively charged quaternary ammonium salt precursor to water is (0.1-20):1; the mass ratio of the initiator to the cross-linking agent is 1:(0.5-2); the total mass of the initiator and the cross-linking agent accounts for 1-10wt% of the total mass of the positively charged quaternary ammonium salt precursor and water; the heating temperature is 40-90° C.; and the cross-linking polymerization time is 5-30 min; In step b3), the mass ratio of the positively charged quaternary ammonium salt precursor, the initiator and the catalyst is 1:(0.05-0.1):(0.005-0.02); the heating temperature is 30-60° C.; and the addition polymerization time is 5-60 min.

7. A method for treating organic pollutants in water, characterized in that: The following processes are included: Using positively charged quaternary ammonium salt polymer catalyst to activate peroxide to degrade organic pollutants in water; The positively charged quaternary ammonium salt polymer catalyst is the positively charged quaternary ammonium salt polymer catalyst according to any one of claims 1 to 2 or the positively charged quaternary ammonium salt polymer catalyst prepared by the preparation method according to any one of claims 3 to 6.

8. The method according to claim 7, characterized in that The processing process specifically includes: A) adding the positively charged quaternary ammonium salt polymer catalyst and peroxide in water, wherein the peroxide degrades organic pollutants in the water under the activation of the positively charged quaternary ammonium salt polymer catalyst; or, B) firstly using the positively charged quaternary ammonium salt polymer catalyst to adsorb organic pollutants in water, and then using peroxide to degrade the adsorbed organic pollutants under the activation of the positively charged quaternary ammonium salt polymer catalyst.

9. The method according to claim 7, characterized in that The usage ratio of the positive quaternary ammonium salt polymer catalyst and the peroxide is (0.05-20) g: (0.1-200) mmol.

10. The method according to claim 7, characterized in that The pH value of the water is 4-12.

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