Preparation method of an adsorbent for printing and dyeing wastewater

Abstract

The present invention relates to the technical field of wastewater treatment, and discloses a preparation method of an adsorbent for printing and dyeing wastewater. Chloromethyl polystyrene resin and a triphenolic hydroxyl modifier are reacted to obtain the adsorbent for printing and dyeing wastewater. The adsorbent contains hydrophilic groups such as an ether bond, a quaternary ammonium salt, a secondary hydroxyl group, and a phenolic hydroxyl group, which is conducive to improving the hydrophilicity and water absorption rate of the adsorbent. The adsorbent contains a large amount of phenolic hydroxyl groups, which are ionized in water to generate phenolic hydroxyl negative ions, which can interact with cationic dyes such as electrostatics. The adsorbent also contains a positively charged quaternary ammonium salt functional group, which also has a strong interaction with anionic dyes, significantly improving the adsorption performance of the adsorbent for anionic and cationic dyes. The adsorbent has good practical application in the treatment of printing and dyeing wastewater.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, in particular to a method for preparing an adsorbent for printing and dyeing wastewater. Background Art

[0002] The textile printing and dyeing industry has developed rapidly in recent years, generating a large amount of printing and dyeing wastewater. This wastewater contains a large number of pollutants such as dyes, inorganic salts, and auxiliaries, making it one of the most difficult industrial wastewaters to treat. Currently, methods for treating printing and dyeing wastewater include adsorption and redox methods. Adsorption methods have the advantages of simple operation, high adsorption efficiency, and a wide range of adsorbent sources. The development of new and efficient adsorbents is a research hotspot. Polystyrene resins have a porous structure and excellent adsorption properties, making them widely used in wastewater treatment. Chinese patent publication number CN117797783A discloses a modified polyaniline-loaded polystyrene adsorption resin, its preparation, and application. Using polystyrene resin as a carrier and polyaniline as a loading material, aniline is in situ polymerized on the surface of the polystyrene resin by a self-assembly method. The resulting polystyrene adsorption resin has excellent adsorption properties for organic dyes and the like. However, this patent only allows the adsorption of anionic dyes such as methyl orange, and does not exhibit good adsorption properties for anionic dyes such as rhodamine B. Summary of the Invention

[0003] The invention provides a method for preparing an adsorbent for printing and dyeing wastewater, which solves the problem that polystyrene resin has poor adsorption performance for anionic and cationic dyes.

[0004] The technical solution of the present invention is a preparation method of an adsorbent for printing and dyeing wastewater: adding chloromethyl polystyrene resin to a solvent, stirring and swelling, then adding a triphenolic hydroxyl modifier, heating to react, filtering, washing with ethanol and water in sequence, and drying to obtain an adsorbent for printing and dyeing wastewater.

[0005] Furthermore, the solvent is chloroform, 1,2-dichloroethane, N,N-dimethylformamide or N,N-dimethylacetamide.

[0006] Furthermore, the mass of the triphenolic hydroxyl modifier is 5-40% of the mass of the chloromethyl polystyrene resin.

[0007] Furthermore, the reaction temperature is 60-110° C., and the reaction time is 18-36 h.

[0008] Furthermore, the preparation method of the triphenolic hydroxy modifier is as follows: 4-[(methylamino)methyl]phenol and glycerol triglycidyl ether are added to a reaction solvent of methanol, ethanol or tetrahydrofuran, heated to 40-55°C, reacted for 12-18 hours, rotary evaporated, washed with petroleum ether, dissolved in ethanol, heated and evaporated, cooled and crystallized to obtain the triphenolic hydroxy modifier. The reaction formula is:

[0009]

[0010] Furthermore, the mass of 4-[(methylamino)methyl]phenol is 330-390% of the mass of glycerol triglycidyl ether.

[0011] Furthermore, the adsorbent for printing and dyeing wastewater is used to adsorb cationic dyes and anionic dyes.

[0012] Technical Effect: The present invention utilizes the tertiary amine group of a triphenolic hydroxyl modifier to undergo a quaternization reaction with the chloromethyl group of a chloromethyl polystyrene resin to obtain an adsorbent for dyeing wastewater. The adsorbent contains hydrophilic groups such as an ether bond, a quaternary ammonium salt, a secondary hydroxyl group, and a phenolic hydroxyl group, which helps improve the adsorbent's hydrophilicity and water absorption rate. The adsorbent contains a large number of phenolic hydroxyl groups, which ionize in water to generate phenolic hydroxyl anions, which can interact with cationic dyes through electrostatic interactions. The positively charged quaternary ammonium salt functional group also interacts strongly with anionic dyes, significantly improving the adsorption performance of the adsorbent for both anionic and cationic dyes. This makes the adsorbent have good practical application in dyeing wastewater treatment. DETAILED DESCRIPTION

[0013] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 creative efforts are within the scope of protection of the present invention.

[0014] Example 1: (1) 2 g of 4-[(methylamino)methyl]phenol (CAS registration number 78507-19-4) and 7.2 g of propylene glycol triglycidyl ether (CAS registration number 13236-02-7) were added to 50 mL of ethanol, heated to 50° C., reacted for 12 h, rotary evaporated, washed with petroleum ether, and the product was dissolved in ethanol, heated for evaporation, cooled and crystallized to obtain a triphenolic hydroxyl modifier.

[0015] (2) Add 20 g of chloromethyl polystyrene resin to 200 mL of 1,2-dichloroethane, stir and swell, then add 1 g of triphenol hydroxyl modifier, heat to 85 ° C, condense and reflux for 24 h, filter, wash with ethanol and water in turn, and dry to obtain an adsorbent for printing and dyeing wastewater.

[0016] Example 2: (1) 2 g of 4-[(methylamino)methyl]phenol and 6.6 g of glycerol triglycidyl ether were added to 50 mL of methanol, heated to 40° C., reacted for 18 h, rotary evaporated, washed with petroleum ether, and the product was dissolved in ethanol, heated for evaporation, cooled and crystallized to obtain a triphenolic hydroxyl modifier.

[0017] (2) Add 20 g of chloromethyl polystyrene resin to 200 mL of chloroform, stir and swell, then add 5 g of triphenol hydroxyl modifier, heat to 60 ° C, condense and reflux for 36 hours, filter, wash with ethanol and water in sequence, and dry to obtain an adsorbent for printing and dyeing wastewater.

[0018] Example 3: (1) 2 g of 4-[(methylamino)methyl]phenol and 7.8 g of glycerol triglycidyl ether were added to 60 mL of tetrahydrofuran, heated to 55° C., reacted for 12 h, rotary evaporated, washed with petroleum ether, and the product was dissolved in ethanol, heated for evaporation, cooled and crystallized to obtain a triphenolic hydroxyl modifier.

[0019] (2) Add 20 g of chloromethyl polystyrene resin to 250 mL of N,N-dimethylacetamide, stir and swell, then add 5 g of triphenol hydroxyl modifier, heat to 110 ° C, react for 18 h, filter, wash with ethanol and water in turn, and dry to obtain an adsorbent for printing and dyeing wastewater.

[0020] Example 4: (1) Add 20 g of chloromethyl polystyrene resin to 300 mL of N,N-dimethylformamide, stir and swell, then add 6.5 g of triphenol hydroxyl modifier, heat to 110°C, react for 18 hours, filter, wash with ethanol and water in turn, and dry to obtain an adsorbent for printing and dyeing wastewater.

[0021] Example 5: (1) Add 20 g of chloromethyl polystyrene resin to 300 mL of N,N-dimethylformamide, stir and swell, then add 8 g of triphenol hydroxyl modifier, heat to 110°C, react for 18 hours, filter, wash with ethanol and water in turn, and dry to obtain an adsorbent for printing and dyeing wastewater.

[0022] In Comparative Example 1, chloromethyl polystyrene resin was used as an adsorbent for printing and dyeing wastewater.

[0023] Comparative Example 2: (1) 20 g of chloromethyl polystyrene resin was added to 200 mL of 1,2-dichloroethane, stirred and swelled, and then 1 g of N,N-dimethylbenzylamine (CAS registration number 103-83-3) was added, heated to 85°C, condensed and refluxed for 24 hours, filtered, washed with ethanol and water in turn, and dried to obtain an adsorbent for printing and dyeing wastewater.

[0024] Comparative Example 3: (1) 20 g of chloromethyl polystyrene resin was added to 200 mL of 1,2-dichloroethane, stirred and swelled, and then 1 g of (dimethylaminomethyl)phenol (CAS registration number 25338-55-0) was added, heated to 85°C, condensed and refluxed for 24 hours, filtered, washed with ethanol and water in turn, and dried to obtain an adsorbent for printing and dyeing wastewater.

[0025] Dry the adsorbent, weigh it, and soak it in distilled water for 24 hours. Remove the adsorbent, blot the surface moisture with filter paper, and weigh it. Calculate the water absorption, W. W = (m - m0) / m0 × 100%. m is the mass after water absorption. The mass before water absorption is the mass.

[0026] Table 1

[0027]

[0028]

[0029] As can be seen from Table 1, compared with the chloromethyl polystyrene resin of Comparative Example 1, the polystyrene resin adsorbents of Examples 1-4 have higher hydrophilicity and water absorption rate. This is because the adsorbent contains hydrophilic groups such as ether bonds, quaternary ammonium salts, secondary hydroxyl groups and phenolic hydroxyl groups, which are beneficial to improving the hydrophilicity and water absorption rate of the adsorbent.

[0030] Comparative Example 2 uses chloromethyl polystyrene resin and N,N-dimethylbenzylamine to carry out quaternization reaction, and the obtained adsorbent does not contain ether bonds, secondary hydroxyl groups and phenolic hydroxyl hydrophilic groups, resulting in the adsorbent's hydrophilicity and water absorption rate being significantly lower than those of the embodiments.

[0031] Comparative Example 3 uses chloromethyl polystyrene resin and (dimethylaminomethyl)phenol to undergo quaternization reaction. The resulting adsorbent does not contain hydrophilic groups such as secondary hydroxyl groups and ether bonds, and has a low content of phenolic hydroxyl groups, resulting in the adsorbent's hydrophilicity and water absorption rate being significantly lower than those of the examples.

[0032] Add 30 mg of adsorbent to 200 mL of 50 mg / L methyl orange solution, stir at 25°C, and allow to adsorb for 3 hours. Centrifuge the supernatant and measure the absorbance and concentration of methyl orange using a UV / Vis spectrophotometer to calculate the adsorption capacity. Q = (C0 - C) × V / M, where C0 is the concentration of the solution before adsorption, C is the concentration of the solution after adsorption, V is the volume of the solution, and M is the mass of the adsorbent.

[0033] Table 3

[0034]

[0035] Add 30 mg of adsorbent to 200 mL of a 50 mg / L Congo red solution and allow to adsorb at 25°C for 4 hours with stirring. Centrifuge the supernatant and measure the absorbance and concentration of methyl orange using a UV / Vis spectrophotometer to calculate the adsorption capacity. Q = (C0 - C) × V / M, where C0 is the concentration of the solution before adsorption, C is the concentration of the solution after adsorption, V is the volume of the solution, and M is the mass of the adsorbent.

[0036] Table 3

[0037]

[0038] Add 20 mg of adsorbent to 200 mL of a 50 mg / L rhodamine B solution at 25°C and allow to adsorb for 4 hours with stirring. Centrifuge the supernatant and measure the absorbance and concentration of methyl orange using a UV / Vis spectrophotometer to calculate the adsorption capacity. Q = (C0 - C) × V / M, where C0 is the concentration of the solution before adsorption, C is the concentration of the solution after adsorption, V is the volume of the solution, and M is the mass of the adsorbent.

[0039] Table 4

[0040]

[0041] As can be seen from the above table, compared with each comparative example, the adsorbent of each embodiment shows very high adsorption capacity for the anionic dyes methyl orange, Congo red, and the cationic dye rhodamine B. This is because the adsorbent has a very high water absorption rate and contains a large amount of phenolic hydroxyl groups, which are ionized in water to generate phenolic hydroxyl negative ions, which can interact with cationic dyes such as electrostatics. At the same time, it contains a positively charged quaternary ammonium salt functional group, which also has a strong interaction with the anionic dye, thereby significantly improving the adsorption performance of the adsorbent for anionic and cationic dyes.

[0042] While the invention has been described above with reference to embodiments, various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention.

Claims

1. A method for preparing an adsorbent for printing and dyeing wastewater, characterized in that: The preparation method comprises the following steps: adding chloromethyl polystyrene resin to a solvent, stirring and swelling, then adding a triphenolic hydroxyl modifier, heating to react, filtering, washing with ethanol and water in sequence, and drying to obtain an adsorbent for printing and dyeing wastewater; The structural formula of the triphenolic hydroxyl modifier is:

2. The method for preparing an adsorbent for printing and dyeing wastewater according to claim 1, wherein The solvent is chloroform, 1,2-dichloroethane, N,N-dimethylformamide or N,N-dimethylacetamide.

3. The method for preparing an adsorbent for printing and dyeing wastewater according to claim 1, wherein: The mass of the triphenolic hydroxy modifier is 5-40% of the mass of the chloromethyl polystyrene resin.

4. The method for preparing an adsorbent for printing and dyeing wastewater according to claim 1, wherein The reaction temperature is 60-110° C., and the reaction time is 18-36 hours.

5. The method for preparing an adsorbent for printing and dyeing wastewater according to claim 1, wherein The preparation method of the triphenolic hydroxy modifier comprises the following steps: adding 4-[(methylamino)methyl]phenol and glycerol triglycidyl ether to a reaction solvent, heating to 40-55° C., reacting for 12-18 hours, rotary evaporation, washing with petroleum ether, dissolving the product in ethanol, heating for evaporation, cooling for crystallization, and obtaining the triphenolic hydroxy modifier.

6. The method for preparing an adsorbent for printing and dyeing wastewater according to claim 5, wherein: The reaction solvent is methanol, ethanol or tetrahydrofuran.

7. The method for preparing an adsorbent for printing and dyeing wastewater according to claim 5, wherein: The mass of the 4-[(methylamino)methyl]phenol is 330-390% of the mass of glycerol triglycidyl ether.

8. Use of the adsorbent for printing and dyeing wastewater obtained by the preparation method according to any one of claims 1 to 7 in adsorbing cationic dyes and anionic dyes.

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