Treatment method of fumaric acid production wastewater
By cross-linking and polymerizing magnesium ion-modified activated carbon with styrene and divinylbenzene to form a composite adsorbent, a three-level pore system was constructed, which solved the problem of low adsorption efficiency of activated carbon and achieved efficient removal of phthalic acid.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-29
- Publication Date
- 2026-03-27
AI Technical Summary
In existing technologies, activated carbon has low adsorption efficiency for phthalic acid in fumaric acid production wastewater, resulting in poor wastewater treatment performance.
A composite adsorbent was formed by cross-linking and polymerization of magnesium ion-modified activated carbon with styrene and divinylbenzene. Magnetic Fe3O4 nanoparticles were modified with silane coupling agents to construct a three-level pore system of macropores, mesopores, and micropores. Oxygen-containing functional groups such as carboxyl and hydroxyl groups were introduced through magnesium ion-modified activated carbon to enhance the adsorption capacity for phthalic acid.
It significantly improves the adsorption and removal rates of phthalic acid, solves the problem of easy clogging of traditional microporous materials, and enhances mass transfer efficiency and adsorption effect.
Smart Images
Figure CN121735491A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a method for treating fumaric acid production wastewater. Background Technology
[0002] Fumaric acid is the simplest unsaturated dicarboxylic acid and an important chemical organic raw material used in the production of unsaturated polyester resins, as an adhesive, and as a raw material for manufacturing fiberglass.
[0003] Fumaric acid is obtained through isomerization of maleic acid, a byproduct of phthalic anhydride production. The production of fumaric acid generates a large amount of acidic wastewater with a CODcr reaching 35,000 g / L, primarily composed of organic acids such as phthalic acid. Current technology uses activated carbon to adsorb phthalic acid from the wastewater to treat it.
[0004] However, due to the low adsorption efficiency of activated carbon, which means that phthalic acid is only physically adsorbed through activated carbon, the removal rate of phthalic acid is relatively low, resulting in poor wastewater treatment. Summary of the Invention
[0005] To address the problems existing in the background technology, the present invention provides a method for treating fumaric acid production wastewater, which can effectively improve the adsorption / removal rate of o-phthalaldehyde.
[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for treating fumaric acid production wastewater includes the following steps: S1. Filter the wastewater to obtain pretreated wastewater; S2. The composite adsorbent is packed into a glass column to form a glass adsorption column; the composite adsorbent is obtained by cross-linking polymerization of magnesium ion modified activated carbon, styrene and divinylbenzene. S3. Load the pretreated wastewater obtained in S1 into a glass adsorption column and collect the effluent.
[0007] Furthermore, the preparation method of the composite adsorbent is as follows: A1. Place the flask in a water bath, add 0.21-0.25g of benzoyl peroxide and 100mL of deionized water to the flask, and stir to dissolve the flask while heating in the water bath to obtain the first reactant. 7.8-8.1g of styrene, 8.1-8.5g of divinylbenzene, 11.7-11.9g of toluene, 1.1-1.2g of Span-80, and 6.9-7.1g of magnesium ion-modified activated carbon were mixed and dispersed uniformly by ultrasonication to obtain a mixture. 0.11-0.13g of surface-modified magnetic Fe3O4 nanoparticles with silane coupling agent were added to the mixture to obtain the second reactant. A2. Argon gas is introduced into the flask of A1 for protection, and the second reactant is added dropwise to the first reactant to obtain the third reactant. During the dropwise addition, the stirring speed and the amount of argon gas introduced are increased. A3. After heating the third reactant to 75°C, stop the argon gas flow and react at 75°C for 5-6 hours. Then, remove the flask from the water bath and allow it to cool naturally. After that, perform magnetic separation on the resulting suspension, wash it multiple times with anhydrous ethanol, and dry it in a constant temperature vacuum drying oven to obtain the composite adsorbent.
[0008] Furthermore, in A1, the temperature of the water bath is 50±2℃, and after the temperature of the first reactant is raised to 50±2℃, it is kept at a constant temperature for 15-20 minutes.
[0009] Furthermore, in A3, the drying temperature is 40-42℃ and the drying time is 24h.
[0010] Furthermore, the preparation process of the magnesium ion modified activated carbon is as follows: B1. The activated carbon is washed three times with distilled water to remove inorganic impurities on the surface, then washed with 0.1 mol / L nitric acid, followed by washing with 1 mol / L sodium hydroxide to remove organic impurities on the surface of the activated carbon, then washed with water until neutral, and then dried to obtain pretreated activated carbon. B2. After impregnating the pretreated activated carbon obtained in B1 in Mg(NO3)2 solution, filter it and dry it in a drying oven to obtain magnesium ion modified activated carbon.
[0011] Furthermore, in B1, the drying temperature is 98-100℃ and the drying time is 12h.
[0012] Furthermore, in B2, the concentration of the Mg(NO3)2 solution is 0.05 mol / L; the ratio of the mass of the pretreated activated carbon to the volume of the Mg(NO3)2 solution is 10 g : (120-150) mL.
[0013] Furthermore, in B2, the immersion time is 22-25 hours.
[0014] Furthermore, in B2, the drying temperature is 120-125℃, and the drying time is 10-14h.
[0015] This application has the following beneficial effects: 1. In this invention, styrene and divinylbenzene monomers begin to polymerize under the action of an initiator (benzoyl peroxide). At this time, the magnesium ion-modified activated carbon added will be partially coated by the resin, forming a "semi-coated" structure. This structure retains the high specific surface area adsorption characteristics of activated carbon while enhancing mechanical strength through the resin layer, preventing pulverization and loss during use. This structure allows phthalic acid molecules to diffuse rapidly to the surface of activated carbon through macroporous channels. At the same time, the hydrophobic environment of the resin layer enhances the affinity for organic acids, thereby improving the adsorption rate.
[0016] 2. Toluene, acting as a porogen, volatilizes during polymerization, forming macroporous channels. At this stage, magnesium ion-modified activated carbon is added, and its own microporous-mesoporous structure can communicate with the macropores formed by resin curing, constructing a three-level pore system of "macropore-mesopore-micropore". This structure not only solves the problem of easy clogging of traditional microporous materials, but also significantly improves the mass transfer efficiency, enabling phthalic acid molecules to quickly reach the active sites, thereby increasing the adsorption rate and improving the removal rate of phthalaldehyde.
[0017] 3. Magnesium ion-modified activated carbon introduces oxygen-containing functional groups such as carboxyl and hydroxyl groups through nitric acid oxidation and loads Mg. 2+ The formation of coordination centers allows for electrostatic attraction or complexation with the carboxyl groups of phthalic acid; while the ester / amide groups in the resin adsorb the benzene ring structure through π-π stacking. The combined effect of these two factors synergistically enhances the adsorption rate and improves the removal rate of phthalic acid. Attached Figure Description
[0018] Figure 1 This is a comparative trend chart of the adsorption capacity test data of phthalic acid by the adsorbents in Examples 1-3 and Comparative Examples 1-4 of the present invention. Figure 2 This is a trend chart comparing the adsorption rate / removal rate of phthalic acid by the adsorbents in Examples 1-3 and Comparative Examples 1-4 of the present invention. Detailed Implementation
[0019] The present application will be further described in detail below with reference to the embodiments.
[0020] Unless otherwise specified, the raw materials used in the embodiments and comparative examples of this application are all commercially available.
[0021] Example 1: (a) The preparation method of magnesium ion modified activated carbon is as follows: B1. First, the activated carbon is washed three times with distilled water to remove inorganic impurities from the surface. Then, it is washed with 0.1 mol / L nitric acid and then with 1 mol / L sodium hydroxide aqueous solution to remove organic impurities from the surface of the activated carbon. Finally, it is washed with water until it is neutral (pH value ≈ 7.0) and dried at 98℃ for 12 hours to obtain pretreated activated carbon.
[0022] B2. The pretreated activated carbon obtained in B1 was impregnated in a 0.05 mol / L Mg(NO3)2 aqueous solution. The mass ratio of the pretreated activated carbon to the volume of the Mg(NO3)2 aqueous solution was 10 g: 135 mL. After a total impregnation time of 24 h, the carbon was filtered, placed in a drying oven, and dried at 122 °C for 12 h to obtain modified activated carbon.
[0023] (II) The preparation method of the composite adsorbent is as follows: A1. Place the flask in a water bath at 50°C. Add 0.23g of benzoyl peroxide and 100mL of deionized water to the flask and stir to dissolve them while heating in the water bath to obtain the first reactant. Note that after the temperature reaches 50°C, keep it at that temperature for 18min.
[0024] 8g of styrene, 8.2g of divinylbenzene, 11.8g of toluene, 1.15g of Span-80, and 7g of magnesium ion-modified activated carbon were mixed and dispersed uniformly by ultrasonication to obtain a mixture. 0.12g of surface-modified magnetic Fe3O4 nanoparticles with silane coupling agent were added to the mixture to obtain the second reactant.
[0025] The specific preparation process of the silane coupling agent surface-modified magnetic Fe3O4 nanoparticles is as follows: Fe3O4 nanoparticles are dried in an oven at 70℃ for 2 hours, soaked in dilute hydrochloric acid (pH≈4) and ultrasonically treated for 15 minutes to remove the oxide layer and impurities, then repeatedly washed with deionized water until neutral, and vacuum dried to obtain pretreated Fe3O4 nanoparticles; γ-aminopropyltriethoxysilane: anhydrous ethanol: deionized water volume ratio = 2:75:25, a small amount of acetic acid is added to adjust the pH to about 4.5 to promote hydrolysis, and a silane solution is obtained; the pretreated Fe3O4 nanoparticles are added to the silane solution, the mass of γ-aminopropyltriethoxysilane is 10% of the mass of Fe3O4 nanoparticles, ultrasonically dispersed for 10 minutes, and stirred at a constant temperature of 70℃ for 8 hours under nitrogen protection. After the reaction is completed, the particles are separated with a magnet, washed three times with ethanol and deionized water in sequence to remove unreacted silane, and dried to obtain the final product.
[0026] A2. Argon gas is introduced into the flask of A1 for protection, and the second reactant is added dropwise to the first reactant. During the dropwise addition, the stirring speed and the amount of argon gas introduced are increased. After the dropwise addition is completed, the third reactant is obtained.
[0027] A3. After heating the third reactant to 75°C, stop the argon gas flow and react at 75°C for 5.5 hours. Then, remove the flask from the water bath and allow it to cool naturally. After that, perform magnetic separation on the resulting suspension, wash it multiple times with anhydrous ethanol, and dry it in a constant temperature vacuum drying oven at 42°C for 24 hours to obtain the composite adsorbent.
[0028] (III) A method for treating fumaric acid production wastewater, comprising the following steps: S1. Filter the wastewater to obtain pretreated wastewater.
[0029] S2. The composite adsorbent is loaded into a glass column to form a glass adsorption column.
[0030] S3. Load the pretreated wastewater obtained in S1 into a glass adsorption column and collect the effluent.
[0031] Example 2: The difference between this example and Example 1 is that the preparation method of the composite adsorbent is as follows: A1. Place the flask in a water bath at 50°C. Add 0.21g of benzoyl peroxide and 100mL of deionized water to the flask and stir to dissolve them while heating in the water bath to obtain the first reactant. Note that after the temperature reaches 50°C, keep it at that temperature for 18min.
[0032] 7.8g of styrene, 8.1g of divinylbenzene, 11.7g of toluene, 1.1g of Span-80, and 6.9g of magnesium ion-modified activated carbon were mixed and dispersed uniformly by ultrasonication to obtain a mixture. 0.11g of surface-modified magnetic Fe3O4 nanoparticles with silane coupling agent were added to the mixture to obtain the second reactant.
[0033] A2. Argon gas is introduced into the flask of A1 for protection, and the second reactant is added dropwise to the first reactant. During the dropwise addition, the stirring speed and the amount of argon gas introduced are increased. After the dropwise addition is completed, the third reactant is obtained.
[0034] A3. After heating the third reactant to 75°C, stop the argon gas flow and react at 75°C for 5.5 hours. Then, remove the flask from the water bath and allow it to cool naturally. After that, perform magnetic separation on the resulting suspension, wash it multiple times with anhydrous ethanol, and dry it in a constant temperature vacuum drying oven at 42°C for 24 hours to obtain the composite adsorbent.
[0035] Example 3: The difference between this example and Example 1 is that the preparation method of the composite adsorbent is as follows: A1. Place the flask in a water bath at 50°C. Add 0.25g of benzoyl peroxide and 100mL of deionized water to the flask and stir to dissolve them while heating in the water bath to obtain the first reactant. Note that after the temperature reaches 50°C, keep it at that temperature for 18min.
[0036] Styrene 8.1g, divinylbenzene 8.5g, toluene 11.9g, Span-80 1.2g, and magnesium ion modified activated carbon 7.1g were mixed and dispersed uniformly by ultrasonication to obtain a mixture. 0.13g of silane coupling agent surface-modified magnetic Fe3O4 nanoparticles were added to the mixture to obtain the second reactant.
[0037] A2. Argon gas is introduced into the flask of A1 for protection, and the second reactant is added dropwise to the first reactant. During the dropwise addition, the stirring speed and the amount of argon gas introduced are increased. After the dropwise addition is completed, the third reactant is obtained.
[0038] A3. After heating the third reactant to 75°C, stop the argon gas flow and react at 75°C for 5.5 hours. Then, remove the flask from the water bath and allow it to cool naturally. After that, perform magnetic separation on the resulting suspension, wash it multiple times with anhydrous ethanol, and dry it in a constant temperature vacuum drying oven at 42°C for 24 hours to obtain the composite adsorbent.
[0039] Comparative Example 1: The difference between this comparative example and Example 1 is that magnesium ion-modified activated carbon is not added in the preparation of the composite adsorbent.
[0040] Comparative Example 2: The difference between this comparative example and Example 1 is that the composite adsorbent is replaced with activated carbon.
[0041] Comparative Example 3: The difference between this comparative example and Example 1 is that in the preparation of the composite adsorbent, magnesium ion modified activated carbon is replaced with activated carbon.
[0042] Comparative Example 4: The difference between this comparative example and Example 1 is that in the preparation of the composite adsorbent, the addition position of magnesium ion modified activated carbon is changed, and magnesium ion modified activated carbon is directly mixed with the preparation product.
[0043] Specifically, the preparation method of the composite adsorbent is as follows: A1. Place the flask in a water bath at 50°C. Add 0.23g of benzoyl peroxide and 100mL of deionized water to the flask and stir to dissolve them while heating in the water bath to obtain the first reactant. Note that after the temperature reaches 50°C, keep it at that temperature for 18min.
[0044] 8g of styrene, 8.2g of divinylbenzene, 11.8g of toluene and 1.15g of Span-80 were mixed and dispersed uniformly by ultrasonication to obtain a mixture. 0.12g of surface-modified magnetic Fe3O4 nanoparticles with silane coupling agent were added to the mixture to obtain the second reactant.
[0045] A2. Argon gas is introduced into the flask of A1 for protection, and the second reactant is added dropwise to the first reactant. During the dropwise addition, the stirring speed and the amount of argon gas introduced are increased. After the dropwise addition is completed, the third reactant is obtained.
[0046] A3. After heating the third reactant to 75°C, stop the argon gas flow and react at 75°C for 5.5 hours. Then, remove the flask from the water bath and allow it to cool naturally. After that, perform magnetic separation on the resulting suspension, wash it multiple times with anhydrous ethanol, dry it in a constant temperature vacuum drying oven at 42°C for 24 hours, and then mix it with 7g of magnesium ion modified activated carbon to obtain the composite adsorbent.
[0047] Experimental Examples: Test Subjects: Examples 1-3 and Comparative Examples 1-4. Experimental Methods: Weigh 0.1000g of the corresponding adsorbent for each test subject into a 150mL ground glass conical flask. Add 100mL of phthalic acid adsorption solution with a concentration of 300mg / g. Place the conical flask in a constant-temperature shaker at 130r / min at 15℃ and shake until adsorption equilibrium is reached. Take a sample and analyze the phthalic acid content using high-performance liquid chromatography (HPLC). Calculate the equilibrium adsorption capacity and adsorption rate of each adsorbent. HPLC Analysis Conditions: Mobile phase: methanol / water = 80 / 20, flow rate: 1.0mL / min, detection wavelength: 254nm, chromatographic column: 150mm C18 column, column temperature: 303K. Experimental Results: See Table 1.
[0048] Table 1. Test Data for Experimental Examples
[0049] Results Analysis: Combining the data in Table 1 and... Figures 1-2 Analysis of Example 1 and Comparative Examples 1-4, specifically comparing Comparative Examples 1, 2 and 3, shows that cross-linking activated carbon and the resin of the present invention to prepare the adsorbent can improve the adsorption rate / removal rate of phthalic acid in the prepared adsorbent.
[0050] By comparing Comparative Example 4 and Example 1, it can be seen that preparing an adsorbent by cross-linking the magnesium ion-modified activated carbon and the resin of the present invention (the magnesium ion-modified activated carbon is introduced during the resin cross-linking polymerization process) can synergistically improve the adsorption rate / removal rate of phthalic acid in the prepared adsorbent. If the two are simply mixed to prepare the adsorbent, the prepared adsorbent cannot achieve the above-mentioned synergistic effect.
[0051] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.
[0052] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.
Claims
1. A method for treating fumaric acid production wastewater, characterized in that, Includes the following steps: S1. The wastewater is filtered to obtain pretreated wastewater; S2. The composite adsorbent is packed into a glass column to form a glass adsorption column; the composite adsorbent is obtained by cross-linking polymerization of magnesium ion modified activated carbon, styrene and divinylbenzene. S3. Load the pretreated wastewater obtained in S1 into a glass adsorption column and collect the effluent.
2. The method for treating fumaric acid production wastewater according to claim 1, characterized in that, The preparation method of the composite adsorbent is as follows: A1. Add 0.21-25g of benzoyl peroxide and 100mL of deionized water to a flask in a water bath, stir to dissolve, and obtain the first reactant; 7.8-8.1g of styrene, 8.1-8.5g of divinylbenzene, 11.7-11.9g of toluene, 1.1-1.2g of Span-80, and 6.9-7.1g of magnesium ion-modified activated carbon were mixed and ultrasonically dispersed. Then, 0.11-0.13g of magnetic Fe3O4 nanoparticles modified with silane coupling agent were added to obtain the second reactant. A2. Under argon protection, the second reactant is added dropwise to the first reactant to obtain the third reactant; A3. After heating the third reactant to 75°C, stop the argon gas flow; after reacting at a constant temperature for 5-6 hours, allow it to cool naturally; then, after magnetic separation, washing, and drying, the composite adsorbent is obtained.
3. The method for treating fumaric acid production wastewater according to claim 2, characterized in that, In A1, the temperature of the water bath is 50±2℃. After the temperature of the first reactant is raised to 50±2℃, it is kept at a constant temperature for 15-20 minutes.
4. The method for treating fumaric acid production wastewater according to claim 2, characterized in that, In A3, the drying temperature is 40-42℃ and the drying time is 24h.
5. The method for treating fumaric acid production wastewater according to claim 1, characterized in that, The preparation method of the magnesium ion modified activated carbon is as follows: B1. The activated carbon is washed sequentially with distilled water, nitric acid and sodium hydroxide solution, then washed with water until neutral, and dried to obtain pretreated activated carbon. B2. The pretreated activated carbon obtained in B1 is impregnated in Mg(NO3)2 solution, filtered, and dried to obtain the magnesium ion modified activated carbon.
6. The method for treating fumaric acid production wastewater according to claim 5, characterized in that, In B1, the drying temperature is 98-100℃ and the drying time is 12 hours.
7. The method for treating fumaric acid production wastewater according to claim 5, characterized in that, In B2, the concentration of the Mg(NO3)2 solution is 0.05 mol / L; the ratio of the mass of the pretreated activated carbon to the volume of the Mg(NO3)2 solution is 10 g : (120-150) mL.
8. The method for treating fumaric acid production wastewater according to claim 5 or 7, characterized in that, In B2, the soaking time is 22-25 hours.
9. The method for treating fumaric acid production wastewater according to claim 5, characterized in that, In B2, the drying temperature is 120-125℃ and the drying time is 10-14h.