A method for the catalytic ozonation of wastewater with a catalyst for organic pollutants

Abstract

This invention discloses a method for treating wastewater using ozone catalysis with organic pollutants, relating to the field of wastewater treatment technology. To address the problem of low catalyst activity and limited ability of ozone to decompose organic matter, the method includes the following steps: A1: Injecting wastewater into a reactor; A2: Adding ozone gas to oxidize organic pollutants; A3: Adding a catalyst to accelerate the ozone oxidation reaction; A4: Enhancing the reaction rate between the catalyst and ozone using a mixer in the reactor to ensure sufficient contact between the two and the wastewater; A5: Retaining and separating solid particles and the catalyst from the treated wastewater using a filter and centrifuge. The catalyst used is titanium dioxide. This invention introduces amino groups onto the surface of titanium dioxide to improve its catalytic activity and selectivity in treating wastewater with ozone. The amino groups increase the surface active sites of titanium dioxide, enhancing the adsorption capacity of organic pollutants on its surface, which is beneficial for the enrichment of organic matter and the catalytic oxidation reaction.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and more particularly to a method for treating wastewater by catalytic ozone treatment of organic pollutants. Background Technology

[0002] Organic pollutants generally refer to organic compounds present in water, such as organic solvents, petroleum hydrocarbons, pesticides, dyes, phenols, phenolic resins, coal tar, petroleum, and petroleum products. These organic pollutants pose certain hazards to the environment and ecosystems. Ozone treatment of wastewater is a common water treatment technology. Ozone can be used to oxidize and decompose organic matter in water, making it a highly efficient oxidant. However, ozone alone is not ideal for oxidizing all organic matter, while adding a catalyst can improve the efficiency of ozone treatment of organic pollutants. The role of catalysts in ozone treatment of wastewater is to accelerate the oxidation reaction, lower the activation energy, and increase the reaction rate and efficiency. Common catalysts include metal oxides, transition metal ions, and transition metal complexes. These catalysts can improve the contact efficiency between organic matter and ozone, promoting the oxidative decomposition reaction of organic matter.

[0003] Currently, many ozone catalyst products have emerged on the market, but most of them suffer from low catalyst activity, limited ability to catalyze the decomposition of organic matter by ozone, and lack of adsorption synergistic function, resulting in low catalyst utilization and short service life. Therefore, there is an urgent need for a method to treat wastewater by catalyzing ozone with organic pollutants. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a method for treating wastewater by catalytic ozone formation using organic pollutants.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for treating wastewater by catalytic ozone treatment of organic pollutants, comprising the following steps:

[0007] A1: Inject wastewater into the reactor;

[0008] A2: Add ozone gas to oxidize organic pollutants;

[0009] A3: Add a catalyst to accelerate the ozone oxidation reaction;

[0010] A4: The reaction rate of the catalyst and ozone is enhanced by the mixing and stirring device in the reactor, so that the two can come into full contact with the wastewater;

[0011] A5: Solid particles and catalysts in the treated wastewater are intercepted and separated through filters and centrifuges.

[0012] Preferably, the catalyst is titanium dioxide.

[0013] Furthermore, the catalyst undergoes surface modification treatment, the specific steps of which are as follows:

[0014] S1: Place titanium dioxide into a measuring cup and expose it fully to the oxidizing environment to increase its surface activity;

[0015] S2: Prepare an aminosilane solution, and then pour the aminosilane solution into a measuring cup for heating and mixing. Remove solid residues and insoluble impurities through a filter.

[0016] S3: The prepared aminosilane solution is introduced into a measuring cup containing titanium dioxide, which promotes the adsorption and chemical reaction between the amino groups in the aminosilane molecules and the active hydroxyl groups on the surface of titanium dioxide, thereby introducing the amino groups onto the surface of titanium dioxide.

[0017] S4: Wash and dry the titanium dioxide with amino groups introduced on the surface to remove unreacted substances and residual solvents;

[0018] S5: The surface-modified titanium dioxide is made into a coating solution and coated onto the honeycomb ceramic balls for use in the reactor.

[0019] Based on the aforementioned scheme: the aminosilane can be replaced with aminosulfonate silane and 3-methoxypropyltrimethoxysilane, and the solvent for aminosilane can be any one of ethanol, acetone, and dimethylformamide.

[0020] A preferred embodiment of the aforementioned scheme is as follows: In step S5, the surface-modified titanium dioxide is prepared into a coating solution and coated onto the honeycomb ceramic spheres. The specific steps are as follows:

[0021] S51: Dissolve the surface-modified titanium dioxide in an acetone solution;

[0022] S52: The mixed solution is ultrasonically treated to promote the dispersion of titanium dioxide particles in the acetone solution;

[0023] S53: Heat treatment of the homogeneous solution promotes cross-linking reaction between particles;

[0024] S54: Add acrylic resin to the heat-treated solution and mix and stir to obtain a coating solution;

[0025] S55: Immerse the honeycomb ceramic balls in the coating solution to coat the surface of the honeycomb ceramic balls with surface-modified titanium dioxide, and then dry the honeycomb ceramic balls after coating.

[0026] As a further aspect of the present invention: the heat treatment time is 30-45 minutes and the temperature is 85-115℃.

[0027] Meanwhile, the concentration of the acrylic resin is in the range of 2-8%.

[0028] As a preferred embodiment of the present invention, in step S3, the reaction temperature is 55-73°C and the reaction time is 1.7-3 hours.

[0029] The beneficial effects of this invention are as follows:

[0030] 1. A method for treating wastewater by catalytic ozone using organic pollutants as a catalyst involves introducing amino groups onto the surface of titanium dioxide to enhance its catalytic activity and selectivity in ozone treatment of wastewater. The amino groups increase the surface active sites of titanium dioxide, improving the adsorption capacity of organic pollutants on its surface, which is beneficial for the enrichment of organic matter and catalytic oxidation reactions. Amino-modified titanium dioxide absorbs more light energy in the visible light region, thereby increasing the efficiency of the photocatalytic reaction and making the catalytic oxidation reaction more efficient. Furthermore, the amino-modified titanium dioxide surface increases active sites, promoting the contact between organic matter and ozone, accelerating the oxidation reaction, and improving the rate and efficiency of the oxidation reaction. Simultaneously, it improves the stability of titanium dioxide, making it more durable and long-lasting in the ozone treatment of wastewater.

[0031] 2. This method for treating wastewater by catalytic ozone treatment using organic pollutants involves coating titanium dioxide onto honeycomb ceramic spheres to increase the reaction interface area, which facilitates the contact between organic matter in the wastewater and ozone, thereby improving the catalytic effect. The honeycomb ceramic spheres have a porous structure, which facilitates mass transfer between organic matter in solution and gaseous ozone. Furthermore, the surface modification of the coated titanium dioxide improves mass transfer efficiency and promotes the catalytic reaction. The surface-modified titanium dioxide coated onto the carrier exhibits good stability and can maintain catalytic activity for a longer period, resulting in a more durable and stable treatment effect. The coating layer on the honeycomb ceramic spheres is easy to regenerate through simple cleaning or other methods, extending its service life. Attached Figure Description

[0032] Figure 1 This is a schematic flowchart of a method for treating wastewater by catalytic ozone using organic pollutants, as proposed in this invention.

[0033] Figure 2 This is a schematic diagram of the process for surface modification of the catalyst in a method for treating wastewater by catalytic ozone of organic pollutants, as proposed in this invention.

[0034] Figure 3 This is a schematic diagram of the process of preparing a coating solution from surface-modified titanium dioxide in a method for treating wastewater with ozone catalysis of organic pollutants, as proposed in this invention. Detailed Implementation

[0035] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0036] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0037] A method for treating wastewater by catalytic ozone treatment of organic pollutants, comprising the following steps:

[0038] A1: Inject wastewater into the reactor;

[0039] A2: Add ozone gas to oxidize organic pollutants;

[0040] A3: A catalyst is added to accelerate the ozone oxidation reaction; the catalyst is titanium dioxide.

[0041] A4: The reaction rate of the catalyst and ozone is enhanced by the mixing and stirring device in the reactor, so that the two can come into full contact with the wastewater;

[0042] A5: Solid particles and catalysts in the treated wastewater are intercepted and separated through filters and centrifuges;

[0043] To promote the full oxidation reaction between the catalyst and wastewater, and to synergistically and effectively adsorb wastewater, such as Figure 1 As shown, the specific steps for surface modification of the catalyst are as follows:

[0044] S1: Weigh 50g of powdered titanium dioxide and put it into a measuring cup, so that the titanium dioxide is fully exposed to the oxidizing environment to increase the surface activity of titanium dioxide;

[0045] S2: Mix 52-63g of aminosilane into 70-82ml of solvent to prepare an aminosilane solution. Pour the aminosilane solution into a measuring cup and heat to mix. Remove solid residues and insoluble impurities through a filter. The heating temperature is 27-60℃. The solvent can be any one of ethanol, acetone, or dimethylformamide. Aminosilane can be replaced with aminosulfonate silane and 3-methoxypropyltrimethoxysilane.

[0046] S3: The prepared aminosilane solution is introduced into a measuring cup containing titanium dioxide to promote the adsorption and chemical reaction between the amino groups in the aminosilane molecules and the active hydroxyl groups on the surface of titanium dioxide, thereby introducing the amino groups onto the surface of titanium dioxide. The reaction temperature is controlled at 55-73℃ and the reaction time is 1.7-3h.

[0047] S4: Wash and dry the titanium dioxide with amino groups introduced on the surface to remove unreacted substances and residual solvents;

[0048] S5: The surface-modified titanium dioxide is made into a coating solution and coated onto the honeycomb ceramic balls for use in the reactor.

[0049] Introducing amino groups onto the surface of titanium dioxide enhances its catalytic activity and selectivity in catalytic ozone treatment of wastewater. Amino groups increase the surface active sites of titanium dioxide, improving the adsorption capacity of organic pollutants on its surface, which is beneficial for the enrichment of organic matter and catalytic oxidation reactions. Amino-modified titanium dioxide absorbs more light energy in the visible light region, thereby increasing the efficiency of photocatalytic reactions and making the catalytic oxidation reaction more efficient. Furthermore, the amino-modified titanium dioxide surface can increase active sites, promote the contact between organic matter and ozone, accelerate the oxidation reaction, and improve the rate and efficiency of the oxidation reaction. At the same time, it improves the stability of titanium dioxide, making it more durable and long-lasting in the ozone treatment of wastewater.

[0050] To ensure sufficient contact between the catalyst and wastewater, expand the reaction area, and improve wastewater treatment quality, such as... Figure 2 As shown, in step S5, the surface-modified titanium dioxide is prepared into a coating solution and coated onto the honeycomb ceramic spheres. The specific steps are as follows:

[0051] S51: Dissolve 40-50g of surface-modified titanium dioxide in 85-110ml of acetone solution;

[0052] S52: The mixed solution is ultrasonically treated to promote the dispersion of titanium dioxide particles in the acetone solution;

[0053] S53: Heat-treat the uniformly mixed solution to promote cross-linking reaction between particles. The heat treatment time is 30-45 min and the temperature is 85-115℃.

[0054] S54: Add 2-8% acrylic resin to the heat-treated solution, mix and stir for 20-35 minutes to obtain the coating solution;

[0055] S55: Immerse the honeycomb ceramic balls in the coating solution to coat the surface of the honeycomb ceramic balls with surface-modified titanium dioxide, and then dry the honeycomb ceramic balls after coating.

[0056] Coating titanium dioxide onto honeycomb ceramic spheres increases the reaction interface area, which is beneficial for the contact between organic matter and ozone in organic wastewater, thus improving the catalytic effect. Furthermore, the porous structure of the honeycomb ceramic spheres facilitates mass transfer between organic matter in solution and gaseous ozone. The surface modification of the coated titanium dioxide further enhances mass transfer efficiency, promoting the catalytic reaction. The surface-modified titanium dioxide coated onto the carrier exhibits good stability, maintaining catalytic activity for a longer period, resulting in a more durable and stable treatment effect. The coating on the honeycomb ceramic spheres is easy to regenerate through simple cleaning or other methods, extending its service life.

[0057] Example 1:

[0058] A method for treating wastewater by catalytic ozone treatment of organic pollutants involves surface modification of the catalyst, and the specific steps are as follows:

[0059] S1: Weigh 50g of powdered titanium dioxide and put it into a measuring cup, so that the titanium dioxide is fully exposed to the oxidizing environment to increase the surface activity of titanium dioxide;

[0060] S2: Mix 55g of aminosilane into 70ml of ethanol to prepare an aminosilane solution. Pour the aminosilane solution into a measuring cup and heat to mix. Remove solid residues and insoluble impurities through a filter. The heating temperature is 37℃.

[0061] S3: The prepared aminosilane solution is introduced into a measuring cup containing titanium dioxide to promote the adsorption and chemical reaction between the amino groups in the aminosilane molecules and the active hydroxyl groups on the surface of titanium dioxide, thereby introducing the amino groups onto the surface of titanium dioxide. The reaction temperature is controlled at 60℃ and the reaction time is 1.8h.

[0062] S4: Wash and dry the titanium dioxide with amino groups introduced on the surface to remove unreacted substances and residual solvents;

[0063] S5: The surface-modified titanium dioxide is made into a coating solution and coated onto the honeycomb ceramic balls for use in the reactor.

[0064] In step S5, the surface-modified titanium dioxide is prepared into a coating solution and coated onto the honeycomb ceramic spheres. The specific steps are as follows:

[0065] S51: Dissolve 40g of surface-modified titanium dioxide in 90ml of acetone solution;

[0066] S52: The mixed solution is ultrasonically treated to promote the dispersion of titanium dioxide particles in the acetone solution;

[0067] S53: Heat-treat the uniformly mixed solution to promote cross-linking reaction between particles. The heat treatment time is 30 min and the temperature is 90℃.

[0068] S54: Add 4% acrylic resin to the heat-treated solution, mix and stir for 22 minutes to obtain the coating solution;

[0069] S55: Immerse the honeycomb ceramic balls in the coating solution to coat the surface of the honeycomb ceramic balls with surface-modified titanium dioxide, and then dry the honeycomb ceramic balls after coating.

[0070] Example 2:

[0071] A method for treating wastewater by catalytic ozone treatment of organic pollutants involves surface modification of the catalyst, and the specific steps are as follows:

[0072] S1: Weigh 50g of powdered titanium dioxide and put it into a measuring cup, so that the titanium dioxide is fully exposed to the oxidizing environment to increase the surface activity of titanium dioxide;

[0073] S2: Mix 59g of aminosilane into 75ml of acetone to prepare an aminosilane solution. Pour the aminosilane solution into a measuring cup and heat to mix. Remove solid residues and insoluble impurities through a filter. The heating temperature is 45℃.

[0074] S3: The prepared aminosilane solution is introduced into a measuring cup containing titanium dioxide to promote the adsorption and chemical reaction between the amino groups in the aminosilane molecules and the active hydroxyl groups on the surface of titanium dioxide, thereby introducing the amino groups onto the surface of titanium dioxide. The reaction temperature is controlled at 57℃ and the reaction time is 2.2h.

[0075] S4: Wash and dry the titanium dioxide with amino groups introduced on the surface to remove unreacted substances and residual solvents;

[0076] S5: The surface-modified titanium dioxide is made into a coating solution and coated onto the honeycomb ceramic balls for use in the reactor.

[0077] In step S5, the surface-modified titanium dioxide is prepared into a coating solution and coated onto the honeycomb ceramic spheres. The specific steps are as follows:

[0078] S51: Dissolve 44g of surface-modified titanium dioxide in 100ml of acetone solution;

[0079] S52: The mixed solution is ultrasonically treated to promote the dispersion of titanium dioxide particles in the acetone solution;

[0080] S53: Heat-treat the uniformly mixed solution to promote cross-linking reaction between particles. The heat treatment time is 35 min and the temperature is 97℃.

[0081] S54: Add 5% acrylic resin to the heat-treated solution, mix and stir for 30 minutes to obtain the coating solution;

[0082] S55: Immerse the honeycomb ceramic balls in the coating solution to coat the surface of the honeycomb ceramic balls with surface-modified titanium dioxide, and then dry the honeycomb ceramic balls after coating.

[0083] Example 3:

[0084] A method for treating wastewater by catalytic ozone treatment of organic pollutants involves surface modification of the catalyst, and the specific steps are as follows:

[0085] S1: Weigh 50g of powdered titanium dioxide and put it into a measuring cup, so that the titanium dioxide is fully exposed to the oxidizing environment to increase the surface activity of titanium dioxide;

[0086] S2: Mix 60g of aminosilane into 80ml of dimethylformamide to prepare an aminosilane solution. Pour the aminosilane solution into a measuring cup and heat to mix. Remove solid residues and insoluble impurities through a filter. The heating temperature is 55℃.

[0087] S3: The prepared aminosilane solution is introduced into a measuring cup containing titanium dioxide to promote the adsorption and chemical reaction between the amino groups in the aminosilane molecules and the active hydroxyl groups on the surface of titanium dioxide, thereby introducing the amino groups onto the surface of titanium dioxide. The reaction temperature is controlled at 67℃ and the reaction time is 2.5h.

[0088] S4: Wash and dry the titanium dioxide with amino groups introduced on the surface to remove unreacted substances and residual solvents;

[0089] S5: The surface-modified titanium dioxide is made into a coating solution and coated onto the honeycomb ceramic balls for use in the reactor.

[0090] In step S5, the surface-modified titanium dioxide is prepared into a coating solution and coated onto the honeycomb ceramic spheres. The specific steps are as follows:

[0091] S51: Dissolve 50g of surface-modified titanium dioxide in 110ml of acetone solution;

[0092] S52: The mixed solution is ultrasonically treated to promote the dispersion of titanium dioxide particles in the acetone solution;

[0093] S53: Heat-treat the uniformly mixed solution to promote cross-linking reaction between particles. The heat treatment time is 42 min and the temperature is 100℃.

[0094] S54: Add 7% acrylic resin to the heat-treated solution, mix and stir for 30 minutes to obtain the coating solution;

[0095] S55: Immerse the honeycomb ceramic balls in the coating solution to coat the surface of the honeycomb ceramic balls with surface-modified titanium dioxide, and then dry the honeycomb ceramic balls after coating.

[0096] Experimental example:

[0097] The wastewater treatment quality was compared and analyzed with the traditional titanium dioxide catalytic ozone treatment process in Examples 1-3 above, as shown in the table below:

[0098]

[0099]

[0100] As shown in the table above, under the condition that the dosage of titanium dioxide, the dosage of ozone, and the catalytic treatment time remain unchanged, the wastewater treatment effect of the traditional titanium dioxide catalytic ozone treatment process is generally poor. Suspended solids and unreacted precipitates are present on the surface of the treated wastewater, and there is still a lot of scum and foam. However, in this application, according to Examples 1-3, amino groups are introduced onto the surface of titanium dioxide, and the titanium dioxide with introduced amino groups is made into a coating solution and coated onto honeycomb ceramic balls. This process has significant advantages in ozone catalytic wastewater treatment. The treated wastewater has obvious transparency, lighter color, reduced odor, and significantly reduced scum and foam.

[0101] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for treating wastewater by catalytic ozone treatment of organic pollutants, characterized in that, Includes the following steps: A1: Inject wastewater into the reactor; A2: Add ozone gas to oxidize organic pollutants; A3: Add a catalyst to accelerate the ozone oxidation reaction; A4: The reaction rate of the catalyst and ozone is enhanced by the mixing and stirring device in the reactor, so that the two can come into full contact with the wastewater; A5: Solid particles and catalysts in the treated wastewater are intercepted and separated through filters and centrifuges; The specific steps for surface modification of the catalyst are as follows: S1: Place titanium dioxide into a measuring cup and expose it fully to the oxidizing environment to increase its surface activity; S2: Prepare an aminosilane solution, and then pour the aminosilane solution into a measuring cup for heating and mixing. Remove solid residues and insoluble impurities through a filter. S3: The prepared aminosilane solution is introduced into a measuring cup containing titanium dioxide, which promotes the adsorption and chemical reaction between the amino groups in the aminosilane molecules and the active hydroxyl groups on the surface of titanium dioxide, thereby introducing the amino groups onto the surface of titanium dioxide. S4: Wash and dry the titanium dioxide with amino groups introduced on the surface to remove unreacted substances and residual solvents; S5: The surface-modified titanium dioxide is made into a coating solution and coated onto the honeycomb ceramic balls for use in the reactor.

2. The method for treating wastewater by catalytic ozone formation using organic pollutants according to claim 1, characterized in that, The catalyst used is titanium dioxide.

3. The method for treating wastewater by catalytic ozone formation using organic pollutants according to claim 2, characterized in that, The aminosilane can be replaced with aminosulfonate silane and 3-methoxypropyltrimethoxysilane, and the solvent for the aminosilane can be any one of ethanol, acetone, and dimethylformamide.

4. The method for treating wastewater by catalytic ozone formation using an organic pollutant as described in claim 3, characterized in that, In step S5, the surface-modified titanium dioxide is prepared into a coating solution and coated onto the honeycomb ceramic spheres. The specific steps are as follows: S51: Dissolve the surface-modified titanium dioxide in an acetone solution; S52: The mixed solution is ultrasonically treated to promote the dispersion of titanium dioxide particles in the acetone solution; S53: Heat treatment of the homogeneous solution promotes cross-linking reaction between particles; S54: Add acrylic resin to the heat-treated solution and mix and stir to obtain a coating solution; S55: Immerse the honeycomb ceramic balls in the coating solution to coat the surface of the honeycomb ceramic balls with surface-modified titanium dioxide, and then dry the honeycomb ceramic balls after coating.

5. The method for treating wastewater by catalytic ozone formation using an organic pollutant as described in claim 4, characterized in that, The heat treatment time is 30-45 minutes and the temperature is 85-115℃.

6. The method for treating wastewater by catalytic ozone formation using an organic pollutant as described in claim 5, characterized in that, The concentration of the acrylic resin is in the range of 2-8%.

7. The method for treating wastewater by catalytic ozone generation of organic pollutants according to claim 6, characterized in that, In step S3, the reaction temperature is 55-73℃ and the reaction time is 1.7-3h.

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