A method for treating wastewater produced by the production of methyl 3-methoxypropionate

Abstract

The present invention relates to the technical field of wastewater treatment, and specifically to a method for treating sewage in the production of methyl 3-methoxypropionate. A method for treating sewage in the production of methyl 3-methoxypropionate includes the following steps: preparation of MnO2-CeZrO2 / C microtube catalyst; microelectrode pretreatment of production sewage; oxidation treatment of pretreated sewage. By preparing the MnO2-CeZrO2 / C microtube catalyst, which has excellent specific surface area and catalytic ability for oxidation reaction, the MnO2-CeZrO2 / C microtube catalyst is added during the subsequent sewage treatment process, and high-temperature and high-pressure oxidation of the pretreated sewage is carried out using air, so that the organic matter in the pretreated sewage is fully oxidized, thereby oxidizing the organic matter into harmless CO2 and H2O, greatly reducing the COD concentration of the pretreated sewage, achieving the discharge standard without subsequent treatment, and the MnO2-CeZrO2 / C microtube catalyst can also be recycled and reused subsequently, saving resources and greatly improving the efficiency of purifying the pretreated sewage.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, in particular to a method for treating production wastewater of 3-methoxymethyl propionate. Background Art

[0002] Methyl 3-methoxypropionate (MMP for short) is an important ether-ester environmentally friendly solvent and organic synthesis intermediate. It is widely used in the fields of cleaning agents, electronic chemicals, coatings, organic synthesis and the synthesis of pharmaceutical intermediates. At present, the most commonly used route for synthesizing MMP is to use anhydrous methanol and methyl acrylate as raw materials, and to obtain it through an etherification addition reaction under the action of a catalyst. Among them, sodium methoxide is the most widely used catalyst. However, when sodium methoxide is used for catalytic production of MMP, acid needs to be added to neutralize the sodium methoxide to quench the reaction, and then the reaction system is distilled. In this process, organic salt wastewater containing methoxypropionate will be produced.

[0003] At present, the main methods for treating organic salt wastewater are incineration and biochemical methods. The incineration method achieves the purpose of treatment by directly incinerating the organic salt wastewater. It has the advantages of mature technology, stable, fast and efficient, small usage space, and high threshold of wastewater adaptability. However, fuel must be added during the treatment process, which increases operating costs. At the same time, the combustion equipment will be damaged by the molten salt produced by the unstable process, and the combustion products may also cause secondary pollution. The biochemical method removes organic matter from the wastewater through the metabolism of anaerobic or aerobic microorganisms. However, the biochemical method occupies a large area and requires a large amount of dilution with cooling water drainage or domestic sewage, resulting in a waste of cooling water. In addition, when the concentration of organic salts is high, it will affect the activity of microorganisms, resulting in unstable sewage treatment. Summary of the invention

[0004] In order to solve the above technical defects, the present invention has developed a method for treating the production wastewater of methyl 3-methoxypropionate which is efficient, stable, has good wastewater treatment effect, and will not cause secondary pollution.

[0005] A method for treating wastewater produced by methyl 3-methoxypropionate, comprising the following steps:

[0006] S1: Preparation of MnO2-CeZrO2 / C microtube catalyst

[0007] Ce(NO3)3·5H2O, Zr(NO3)4·5H2O and glutaraldehyde solution are mixed and magnetically stirred, then carbon nanotubes are added and stirred continuously, and then placed in a reaction kettle for high-temperature heating to obtain solid substance I, which is then washed, dried and calcined after cooling to obtain CeZrO2 / C microtubes, and CeZrO2 / C microtubes are added to MnSO4 solution, stirred and then dropwise added to KMnO4 solution, stirred continuously and filtered to obtain solid substance II, which is washed and dried to obtain MnO2-CeZrO2 / C microtube catalyst;

[0008] S2: Microelectrode pretreatment of industrial wastewater

[0009] The carbon fiber powder and the Cu powder are loaded into an electrolytic column, and a power source is connected to obtain a Cu-C electrolytic column, and the production wastewater of methyl 3-methoxypropionate, sodium dodecyl sulfate and hydrogen peroxide are evenly mixed to obtain a mixed solution, and the Cu-C electrolytic column is immersed in the mixed solution, and the voltage is adjusted and the Cu-C electrolytic column is used for stirring, and the mixed solution is irradiated with ultraviolet rays to obtain pretreated wastewater;

[0010] S3: Oxidation treatment of pre-treated wastewater

[0011] The MnO2-CeZrO2 / C microtube catalyst and pretreated sewage are stirred evenly and then ultrasonically treated, and then placed in a catalytic wet oxidation device for oxidation treatment to obtain a gas-liquid mixture, which is cooled and decompressed, and then separated into gas and liquid phase substances by a gas-liquid separator, and the gas phase substance is directly discharged into the atmosphere, and the liquid phase substance is centrifugally separated and filtered to obtain an aqueous phase and a turbid phase, and the aqueous phase is directly discharged, and the turbid phase is washed with deionized water and then dried to obtain the MnO2-CeZrO2 / C microtube catalyst.

[0012] Furthermore, the preparation of the step S1MnO2-CeZrO2 / C microtube catalyst comprises the following steps:

[0013] S1.1: Ce(NO3)3·5H2O, Zr(NO3)4·5H2O and glutaraldehyde solution are placed in a container at a mass ratio of 1:(2-3):(25-30), and magnetic stirring is performed at a stirring speed of 150-200 rpm for 20-25 minutes to obtain a uniform solution, and then 10-12wt% of carbon nanotubes are added, and stirring is continued at a stirring speed of 150-200 rpm for 25-30 minutes, and then placed in a reactor and heated at a temperature of 120-130°C for 3-4 hours to obtain solid substance I. After the solid substance I is cooled to room temperature, it is rinsed with deionized water until the deionized water after rinsing is neutral, and then placed in a drying oven and dried at a temperature of 60-65°C for 2-3 hours, and then placed in a muffle furnace and calcined at a temperature of 350-400°C for 2.5-3 hours to obtain CeZrO2 / C microtubes;

[0014] S1.2: Take 2-3 parts by weight of CeZrO2 / C microtubes and add them to 4-5 parts by weight of MnSO4 solution. After stirring for 15-20 minutes, add them dropwise to 4-5 parts by weight of KMnO4 solution. Continue stirring for 25-30 minutes, then filter to obtain solid substance II, rinse with deionized water until the deionized water after rinsing is neutral, and then place in a drying oven and dry at 70-75°C for 2-3 hours to obtain MnO2-CeZrO2 / C microtube catalyst.

[0015] Furthermore, step S2 produces microelectrode pretreatment of wastewater, comprising the following steps:

[0016] S2.1: Carbon fiber powder and Cu powder are loaded into an electrolytic column at a volume ratio of 1: (1-1.5), with a filler amount of 75-80%, and then connected to a power source to obtain a Cu-C electrolytic column;

[0017] S2.2: Place the production wastewater of methyl 3-methoxypropionate, sodium dodecyl sulfate and hydrogen peroxide in a container at a mass ratio of 1:(0.08-0.1):(0.1-0.2) and mix them evenly to obtain mixed wastewater, immerse the Cu-C electrolytic column in the mixed wastewater, adjust the power supply voltage to 2-3V, and then use the Cu-C electrolytic column to gently stir the mixed solution, and at the same time irradiate the mixed solution with an ultraviolet lamp for 15-20 minutes to obtain pretreated wastewater.

[0018] Furthermore, step S3 is the oxidation treatment of the pre-treated sewage, comprising the following steps:

[0019] S3.1: Place the MnO2-CeZrO2 / C microtube catalyst and pretreated sewage in a container at a mass ratio of 0.1:(6-8), stir evenly and then perform ultrasonic treatment at a frequency of 20-25KHz for 20-25 minutes, then place in a catalytic wet oxidation device and adjust the temperature to 270-280℃, the pressure to 6-8Mpa, and the liquid space velocity to 1-1.5h -1 , and carry out oxidation treatment for 3-4 hours to oxidize the organic compounds in the pretreated sewage into CO2 and H2O to obtain a gas-liquid mixture;

[0020] S3.2: The gas-liquid mixture is sent to a heat exchanger for cooling and then decompressed to atmospheric pressure, and then sent to a gas-liquid separator to separate gas and liquid phase substances. The gas phase substance is directly discharged into the atmosphere, and the liquid phase substance is centrifuged and filtered to obtain an aqueous phase and a turbid phase. The aqueous phase is directly discharged, and the turbid phase is washed with deionized water and then dried to obtain a MnO2-CeZrO2 / C microtube catalyst.

[0021] Furthermore, the concentration of the glutaraldehyde solution in step S1.1 is 10-15%.

[0022] Furthermore, in step S1.2, the concentrations of the MnSO4 solution and the KMnO4 solution are both 30-40 wt%.

[0023] Furthermore, the material of the electrolytic column in step S2.1 is PP material.

[0024] Furthermore, the main components of the production wastewater of methyl 3-methoxypropionate in step S2.2 are sodium methoxypropionate, ethanol and methyl acrylate.

[0025] Furthermore, in step S2.2, the power of the ultraviolet lamp is 80-100W.

[0026] Furthermore, in step S3.1, the catalytic wet oxidation device uses air for oxidation treatment.

[0027] The beneficial effects are as follows: 1. The present invention prepares MnO2-CeZrO2 / C microtube catalysts, which have excellent specific surface area and catalytic ability for oxidation reactions. In the subsequent sewage treatment process, the MnO2-CeZrO2 / C microtube catalysts are added, and the pretreated sewage is oxidized at high temperature and high pressure by air, so that the organic matter in the pretreated sewage is fully oxidized, so that the organic matter is oxidized into harmless CO2 and H2O, which greatly reduces the COD concentration of the pretreated sewage and meets the emission standards without subsequent treatment. In addition, the MnO2-CeZrO2 / C microtube catalysts can be recycled and reused, which saves resources and greatly improves the efficiency of purifying the pretreated sewage.

[0028] 2. The present invention prepares a Cu-C electrolytic column, and then immerses the Cu-C electrolytic column in mixed sewage consisting of production sewage of methyl 3-methoxypropionate, a surfactant and hydrogen peroxide, and irradiates the mixed sewage with ultraviolet rays while stirring the Cu-C electrolytic column, so that the hydrogen peroxide in the mixed sewage is preliminarily decomposed into hydroxyl radicals, and the hydroxyl radicals are uniformly dispersed in the mixed liquid while stirring, and the organic matter in the mixed sewage is oxidized and activated, thereby improving the effect of subsequent high-temperature and high-pressure oxidation of pretreated sewage by air, increasing the purification speed of the pretreated sewage, and thus better reducing the COD concentration of the pretreated sewage.

[0029] 3. The present invention stirs and mixes the MnO2-CeZrO2 / C microtube catalyst and pretreated sewage and then performs ultrasonic treatment, so that the MnO2-CeZrO2 / C microtube catalyst is evenly dispersed in the pretreated sewage, thereby enhancing the catalysis of the MnO2-CeZrO2 / C microtube catalyst on the air oxidation process of organic matter, thereby improving the speed and effect of pretreated sewage purification. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of the method for treating wastewater produced by the production of methyl 3-methoxypropionate used in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe 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 creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] A method for treating wastewater produced by methyl 3-methoxypropionate, such as Figure 1 As shown, the following steps are included:

[0034] S1: Preparation of MnO2-CeZrO2 / C microtube catalyst

[0035] S1.1: Ce(NO3)3·5H2O, Zr(NO3)4·5H2O and 10% glutaraldehyde solution are placed in a container at a mass ratio of 1:2:25, and magnetic stirring is performed at a stirring speed of 150 rpm for 20 minutes to obtain a uniform solution, and then 10wt% carbon nanotubes are added, and stirring is continued at a stirring speed of 150 rpm for 25 minutes, and then placed in a reactor and heated at a temperature of 120°C for 3 hours to obtain solid substance I. After solid substance I is cooled to room temperature, it is rinsed with deionized water until the deionized water after rinsing is neutral, and then placed in a drying oven and dried at a temperature of 60°C for 2 hours, and then placed in a muffle furnace and calcined at a temperature of 350°C for 2.5 hours to obtain CeZrO2 / C microtubes;

[0036] S1.2: Take 2 parts by weight of CeZrO2 / C microtubes and add them to 4 parts by weight of MnSO4 solution. After stirring for 15 minutes, add them dropwise to 4 parts by weight of KMnO4 solution. The concentrations of MnSO4 solution and KMnO4 solution are both 30wt%. Continue stirring for 25 minutes, then filter to obtain solid substance II, rinse with deionized water until the deionized water after rinsing is neutral, and then place in a drying oven and dry at 70°C for 2 hours to obtain MnO2-CeZrO2 / C microtube catalyst.

[0037] S2: Microelectrode pretreatment of industrial wastewater

[0038] S2.1: Carbon fiber powder and Cu powder are loaded into an electrolytic column made of PP material at a volume ratio of 1:1, with a filler amount of 75%, and then connected to a power source to obtain a Cu-C electrolytic column;

[0039] S2.2: Place the production wastewater of methyl 3-methoxypropionate, sodium dodecyl sulfate and hydrogen peroxide in a mass ratio of 1:0.08:0.1 in a container and mix evenly. The main components of the production wastewater of methyl 3-methoxypropionate are sodium methoxypropionate, ethanol and methyl acrylate. Get mixed wastewater, immerse the Cu-C electrolytic column in the mixed wastewater, adjust the power supply voltage to 2V, and then use the Cu-C electrolytic column to gently stir the mixed liquid. At the same time, irradiate the mixed liquid with an ultraviolet lamp. The power of the ultraviolet lamp is adjusted to 80W for 15 minutes to obtain pretreated wastewater.

[0040] S3: Oxidation treatment of pre-treated wastewater

[0041] S3.1: Place the MnO2-CeZrO2 / C microtube catalyst and pretreated sewage in a container at a mass ratio of 0.1:6, stir evenly, and then perform ultrasonic treatment at a frequency of 20KHz for 20 minutes. Then place it in a catalytic wet oxidation device and adjust the temperature to 270℃, the pressure to 6Mpa, and the liquid space velocity to 1h -1, using air for oxidation treatment for 3 hours to oxidize the organic compounds in the pretreated sewage into CO2 and H2O to obtain a gas-liquid mixture;

[0042] S3.2: The gas-liquid mixture is sent to a heat exchanger for cooling and then decompressed to atmospheric pressure, and then sent to a gas-liquid separator to separate gas and liquid phase substances. The gas phase substance is directly discharged into the atmosphere, and the liquid phase substance is centrifuged and filtered to obtain an aqueous phase and a turbid phase. The aqueous phase is directly discharged, and the turbid phase is washed with deionized water and then dried to obtain a MnO2-CeZrO2 / C microtube catalyst.

[0043] Example 2

[0044] A method for treating wastewater produced by methyl 3-methoxypropionate, such as Figure 1 As shown, the following steps are included:

[0045] S1: Preparation of MnO2-CeZrO2 / C microtube catalyst

[0046] S1.1: Ce(NO3)3·5H2O, Zr(NO3)4·5H2O and 10% glutaraldehyde solution are placed in a container at a mass ratio of 1:3:30, and magnetic stirring is performed at a stirring speed of 150 rpm for 20 minutes to obtain a uniform solution, and then 12wt% carbon nanotubes are added, and stirring is continued at a stirring speed of 150 rpm for 25 minutes, and then placed in a reactor and heated at a temperature of 120°C for 3 hours to obtain solid substance I. After solid substance I is cooled to room temperature, it is rinsed with deionized water until the deionized water after rinsing is neutral, and then placed in a drying oven at a temperature of 60°C for 2 hours, and then placed in a muffle furnace and calcined at a temperature of 350°C for 2.5 hours to obtain CeZrO2 / C microtubes;

[0047] S1.2: Take 3 parts by weight of CeZrO2 / C microtubes and add them to 5 parts by weight of MnSO4 solution. After stirring for 15 minutes, add them dropwise to 5 parts by weight of KMnO4 solution. The concentrations of MnSO4 solution and KMnO4 solution are both 30wt%. Continue stirring for 25 minutes, then filter to obtain solid substance II, rinse with deionized water until the deionized water after rinsing is neutral, and then place in a drying oven and dry at 70°C for 2 hours to obtain MnO2-CeZrO2 / C microtube catalyst.

[0048] S2: Microelectrode pretreatment of industrial wastewater

[0049] S2.1: Carbon fiber powder and Cu powder are loaded into an electrolytic column made of PP material at a volume ratio of 1:1.5, with a filler amount of 75%, and then connected to a power source to obtain a Cu-C electrolytic column;

[0050] S2.2: Place the production wastewater of methyl 3-methoxypropionate, sodium dodecyl sulfate and hydrogen peroxide in a mass ratio of 1:0.1:0.2 in a container and mix them evenly. The main components of the production wastewater of methyl 3-methoxypropionate are sodium methoxypropionate, ethanol and methyl acrylate. Get mixed wastewater, immerse the Cu-C electrolytic column in the mixed wastewater, adjust the power supply voltage to 2V, and then use the Cu-C electrolytic column to gently stir the mixed liquid. At the same time, irradiate the mixed liquid with an ultraviolet lamp. The power of the ultraviolet lamp is adjusted to 80W for 15 minutes to obtain pretreated wastewater.

[0051] S3: Oxidation treatment of pre-treated wastewater

[0052] S3.1: Place the MnO2-CeZrO2 / C microtube catalyst and pretreated sewage in a container at a mass ratio of 0.1:8, stir evenly, and then perform ultrasonic treatment at a frequency of 20KHz for 20 minutes. Then place it in a catalytic wet oxidation device and adjust the temperature to 270℃, the pressure to 6Mpa, and the liquid space velocity to 1h -1 , using air for oxidation treatment for 3 hours to oxidize the organic compounds in the pretreated sewage into CO2 and H2O to obtain a gas-liquid mixture;

[0053] S3.2: The gas-liquid mixture is sent to a heat exchanger for cooling and then decompressed to atmospheric pressure, and then sent to a gas-liquid separator to separate gas and liquid phase substances. The gas phase substance is directly discharged into the atmosphere, and the liquid phase substance is centrifuged and filtered to obtain an aqueous phase and a turbid phase. The aqueous phase is directly discharged, and the turbid phase is washed with deionized water and then dried to obtain a MnO2-CeZrO2 / C microtube catalyst.

[0054] Example 3

[0055] A method for treating wastewater produced by methyl 3-methoxypropionate, such as Figure 1 As shown, the following steps are included:

[0056] S1: Preparation of MnO2-CeZrO2 / C microtube catalyst

[0057] S1.1: Ce(NO3)3·5H2O, Zr(NO3)4·5H2O and 15% glutaraldehyde solution were placed in a container at a mass ratio of 1:2:25, and magnetic stirring was performed at a stirring speed of 200 rpm for 25 minutes to obtain a uniform solution, and then 10wt% carbon nanotubes were added, and stirring was continued at a stirring speed of 200 rpm for 30 minutes, and then placed in a reactor and heated at a temperature of 130°C for 4 hours to obtain solid substance I. After solid substance I was cooled to room temperature, it was rinsed with deionized water until the deionized water after rinsing was neutral, and then placed in a drying oven and dried at a temperature of 65°C for 3 hours, and then placed in a muffle furnace and calcined at a temperature of 400°C for 3 hours to obtain CeZrO2 / C microtubes;

[0058] S1.2: Take 2 parts by weight of CeZrO2 / C microtubes and add them to 4 parts by weight of MnSO4 solution. After stirring for 20 minutes, add them dropwise to 4 parts by weight of KMnO4 solution. The concentrations of MnSO4 solution and KMnO4 solution are both 40wt%. Continue stirring for 30 minutes, then filter to obtain solid substance II, rinse with deionized water until the deionized water after rinsing is neutral, and then place in a drying oven and dry at 75°C for 3 hours to obtain MnO2-CeZrO2 / C microtube catalyst.

[0059] S2: Microelectrode pretreatment of industrial wastewater

[0060] S2.1: Carbon fiber powder and Cu powder are loaded into an electrolytic column made of PP material at a volume ratio of 1:1, with a filler amount of 80%, and then connected to a power source to obtain a Cu-C electrolytic column;

[0061] S2.2: Place the production wastewater of methyl 3-methoxypropionate, sodium dodecyl sulfate and hydrogen peroxide in a mass ratio of 1:0.08:0.1 in a container and mix evenly. The main components of the production wastewater of methyl 3-methoxypropionate are sodium methoxypropionate, ethanol and methyl acrylate. Get mixed wastewater, immerse the Cu-C electrolytic column in the mixed wastewater, adjust the power supply voltage to 3V, and then use the Cu-C electrolytic column to gently stir the mixed liquid. At the same time, irradiate the mixed liquid with an ultraviolet lamp. The power of the ultraviolet lamp is adjusted to 100W for 20 minutes to obtain pretreated wastewater.

[0062] S3: Oxidation treatment of pre-treated wastewater

[0063] S3.1: Place the MnO2-CeZrO2 / C microtube catalyst and pretreated sewage in a container at a mass ratio of 0.1:6, stir evenly and then perform ultrasonic treatment at a frequency of 25KHz for 25 minutes, then place in a catalytic wet oxidation device and adjust the temperature to 280℃, the pressure to 8Mpa, and the liquid space velocity to 1.5h -1, using air for oxidation treatment for 4 hours to oxidize the organic compounds in the pretreated sewage into CO2 and H2O to obtain a gas-liquid mixture;

[0064] S3.2: The gas-liquid mixture is sent to a heat exchanger for cooling and then decompressed to atmospheric pressure, and then sent to a gas-liquid separator to separate gas and liquid phase substances. The gas phase substance is directly discharged into the atmosphere, and the liquid phase substance is centrifuged and filtered to obtain an aqueous phase and a turbid phase. The aqueous phase is directly discharged, and the turbid phase is washed with deionized water and then dried to obtain a MnO2-CeZrO2 / C microtube catalyst.

[0065] Comparative Example 1

[0066] Compared with Example 1, the difference of Comparative Example 1 is that step S1 is removed in Comparative Example 1, and the MnO2-CeZrO2 / C microtube catalyst in the subsequent step is replaced by Co3O4 catalyst, and the remaining steps are the same as those in Example 1.

[0067] Comparative Example 2

[0068] Compared with Example 1, the difference of Comparative Example 2 is that step S2 is removed in Comparative Example 2, and the pretreated wastewater in the subsequent step is replaced by the production wastewater of 3-methoxypropionic acid methyl ester, and the remaining steps are the same as those in Example 1.

[0069] Comparative Example 3

[0070] Compared with Example 1, the difference of Comparative Example 2 is that, in Comparative Example 3, ultrasonic treatment is not performed in step S3.1, and S3.1 is modified to place the MnO2-CeZrO2 / C microtube catalyst and the pretreated sewage in a mass ratio of 0.1:6 in a container and stir evenly, and then place it in a catalytic wet oxidation device, adjust the temperature to 270°C, the pressure to 6 MPa, and the liquid space velocity to 1 h -1 , air is used for oxidation treatment until the organic compounds in the pretreated sewage are oxidized into CO2 and H2O to obtain a gas-liquid mixture, and the remaining steps are the same as those in Example 1.

[0071] 100 ml was taken from the same batch of 3-methoxypropionic acid methyl ester production wastewater, and the initial COD value C1 was measured by potassium dichromate method. Then, three portions of water phase were prepared by the process steps of Example, Comparative Example 1, Comparative Example 2 and Comparative Example 3, and 100 ml was taken respectively to measure the COD value C2 of the water phase by potassium dichromate method. Then, the COD purification rate of Example, Comparative Example 1, Comparative Example 2 and Comparative Example 3 was calculated by the formula COD purification rate = (C1-C2) / C1×100%, as shown in Table 1, it can be seen that The COD purification rate of the embodiment is greater than the COD purification rate of the comparative example 3, the COD purification rate of the comparative example 2, and the COD purification rate of the comparative example 1. It can be seen that the COD purification rate of the embodiment with the addition of the MnO2-CeZrO2 / C microtube catalyst is higher than the COD purification rate of the comparative example 1 with the addition of the Co3O4 catalyst, which can prove that the preparation of the MnO2-CeZrO2 / C microtube catalyst and the addition of the catalyst to the oxidation treatment of the pre-treated sewage can well enhance the sewage treatment effect, thereby reducing the COD value of the sewage;

[0072] Similarly, it can be seen from the table that the COD purification rate of the embodiment is greater than the COD purification rate of the comparative example 2, which can prove that microelectrode pretreatment of production wastewater can also enhance the wastewater treatment effect and reduce the COD value of the wastewater. At the same time, the fact that the COD purification rate of the embodiment is greater than the COD purification rate of the comparative example 3 can prove that ultrasonic treatment of the mixed solution of MnO2-CeZrO2 / C microtube catalyst and pretreated wastewater can also enhance the wastewater treatment effect and reduce the COD value of the wastewater.

[0073] Table 1: COD purification rate of production wastewater of methyl 3-methoxypropionate

[0074] COD purification rate / % The first Second copy The third Example 1 99.8 99.6 99.9 Example 2 99.7 99.9 99.9 Example 3 99.9 99.7 99.8 Comparative Example 1 96.8 96.5 96.7 Comparative Example 2 97.5 97.3 97.1 Comparative Example 3 99.1 98.9 99.2

[0075] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for treating wastewater produced by the production of methyl 3-methoxypropionate, characterized in that: The following steps are involved: S1: Preparation of MnO2-CeZrO2 / C microtube catalyst Ce(NO3)3·5H2O, Zr(NO3)4·5H2O and glutaraldehyde solution are mixed and magnetically stirred, then carbon nanotubes are added and stirred continuously, and then placed in a reaction kettle for high-temperature heating to obtain solid substance I, which is then washed, dried and calcined after cooling to obtain CeZrO2 / C microtubes, and CeZrO2 / C microtubes are added to MnSO4 solution, stirred and then dropwise added to KMnO4 solution, stirred continuously and filtered to obtain solid substance II, which is washed and dried to obtain MnO2-CeZrO2 / C microtube catalyst; S2: Microelectrode pretreatment of industrial wastewater The carbon fiber powder and the Cu powder are loaded into an electrolytic column, and a power source is connected to obtain a Cu-C electrolytic column, and the production wastewater of methyl 3-methoxypropionate, sodium dodecyl sulfate and hydrogen peroxide are evenly mixed to obtain a mixed solution, and the Cu-C electrolytic column is immersed in the mixed solution, and the voltage is adjusted and the Cu-C electrolytic column is used for stirring, and the mixed solution is irradiated with ultraviolet rays to obtain pretreated wastewater; S3: Oxidation treatment of pre-treated wastewater The MnO2-CeZrO2 / C microtube catalyst and pretreated sewage are stirred evenly and then ultrasonically treated, and then placed in a catalytic wet oxidation device for oxidation treatment to obtain a gas-liquid mixture, which is cooled and decompressed, and then separated into gas and liquid phase substances by a gas-liquid separator, and the gas phase substance is directly discharged into the atmosphere, and the liquid phase substance is centrifugally separated and filtered to obtain an aqueous phase and a turbid phase, and the aqueous phase is directly discharged, and the turbid phase is washed with deionized water and then dried to obtain the MnO2-CeZrO2 / C microtube catalyst.

2. The method for treating wastewater produced by the production of methyl 3-methoxypropionate according to claim 1, characterized in that: Step S1: Preparation of MnO2-CeZrO2 / C micro-tube catalyst, comprising the following steps: S1.1: Ce(NO3)3·5H2O, Zr(NO3)4·5H2O and glutaraldehyde solution are placed in a container at a mass ratio of 1:(2-3):(25-30), and magnetic stirring is performed at a stirring speed of 150-200 rpm for 20-25 minutes to obtain a uniform solution, and then 10-12wt% of carbon nanotubes are added, and stirring is continued at a stirring speed of 150-200 rpm for 25-30 minutes, and then placed in a reactor and heated at a temperature of 120-130°C for 3-4 hours to obtain solid substance I. After the solid substance I is cooled to room temperature, it is rinsed with deionized water until the deionized water after rinsing is neutral, and then placed in a drying oven and dried at a temperature of 60-65°C for 2-3 hours, and then placed in a muffle furnace and calcined at a temperature of 350-400°C for 2.5-3 hours to obtain CeZrO2 / C microtubes; S1.2: Take 2-3 parts by weight of CeZrO2 / C microtubes and add them to 4-5 parts by weight of MnSO4 solution. After stirring for 15-20 minutes, add them dropwise to 4-5 parts by weight of KMnO4 solution. Continue stirring for 25-30 minutes, then filter to obtain solid substance II, rinse with deionized water until the deionized water after rinsing is neutral, and then place in a drying oven and dry at 70-75°C for 2-3 hours to obtain MnO2-CeZrO2 / C microtube catalyst.

3. A method for treating wastewater produced by the production of methyl 3-methoxypropionate according to claim 2, characterized in that: Step S2 produces microelectrode pretreatment of wastewater, comprising the following steps: S2.1: Carbon fiber powder and Cu powder are loaded into an electrolytic column at a volume ratio of 1: (1-1.5), with a filler amount of 75-80%, and then connected to a power source to obtain a Cu-C electrolytic column; S2.2: Mix the production wastewater of methyl 3-methoxypropionate, sodium dodecyl sulfate and hydrogen peroxide at a ratio of 1: The mass ratio of (0.08-0.1):(0.1-0.2) is placed in a container and mixed evenly to obtain mixed sewage, the Cu-C electrolytic column is immersed in the mixed sewage, the power supply voltage is adjusted to 2-3V, and then the Cu-C electrolytic column is used to slightly stir the mixed solution, and the mixed solution is irradiated with an ultraviolet lamp for 15-20 minutes to obtain pretreated sewage.

4. The method for treating wastewater produced by the production of methyl 3-methoxypropionate according to claim 3, characterized in that: Step S3 is the oxidation treatment of the pre-treated sewage, comprising the following steps: S3.1: Place the MnO2-CeZrO2 / C microtube catalyst and pretreated sewage in a container at a mass ratio of 0.1:(6-8), stir evenly and then perform ultrasonic treatment at a frequency of 20-25KHz for 20-25 minutes, then place in a catalytic wet oxidation device and adjust the temperature to 270-280℃, the pressure to 6-8Mpa, and the liquid space velocity to 1-1.5h -1 , and carry out oxidation treatment for 3-4 hours to oxidize the organic compounds in the pretreated sewage into CO2 and H2O to obtain a gas-liquid mixture; S3.2: The gas-liquid mixture is sent to a heat exchanger for cooling and then decompressed to atmospheric pressure, and then sent to a gas-liquid separator to separate gas and liquid phase substances. The gas phase substance is directly discharged into the atmosphere, and the liquid phase substance is centrifuged and filtered to obtain an aqueous phase and a turbid phase. The aqueous phase is directly discharged, and the turbid phase is washed with deionized water and then dried to obtain a MnO2-CeZrO2 / C microtube catalyst.

5. The method for treating wastewater produced by the production of methyl 3-methoxypropionate according to claim 2, characterized in that: The concentration of the glutaraldehyde solution in step S1.1 is 10-15%.

6. The method for treating wastewater produced by the production of methyl 3-methoxypropionate according to claim 2, characterized in that: The concentrations of the MnSO4 solution and the KMnO4 solution in step S1.2 are both 30-40 wt%.

7. The method for treating wastewater produced by the production of methyl 3-methoxypropionate according to claim 3, characterized in that: The material of the electrolytic column in step S2.1 is PP material.

8. The method for treating wastewater produced by the production of methyl 3-methoxypropionate according to claim 3, characterized in that: The main components of the production wastewater of methyl 3-methoxypropionate in step S2.2 are sodium methoxypropionate, ethanol and methyl acrylate.

9. The method for treating wastewater produced by the production of methyl 3-methoxypropionate according to claim 3, characterized in that: The power of the UV lamp in step S2.2 is 80-100W.

10. The method for treating wastewater produced by the production of methyl 3-methoxypropionate according to claim 4, characterized in that: In step S3.1, the catalytic wet oxidation device uses air for oxidation treatment.

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