Preparation method of adsorbent for printing and dyeing wastewater

Abstract

The invention relates to the technical field of wastewater treatment, and discloses a preparation method of an adsorbent for printing and dyeing wastewater, and the adsorbent for printing and dyeing wastewater is obtained by reacting chloromethyl polystyrene resin with a triphenolic hydroxyl modifier. The adsorbent contains ether bonds, quaternary ammonium salt, secondary hydroxyl groups, phenolic hydroxyl groups and other hydrophilic groups, and the hydrophilicity and the water absorption rate of the adsorbent can be improved. According to the present invention, the phenolic hydroxyl group-containing quaternary ammonium salt functional group contains a large amount of phenolic hydroxyl groups, can be ionized in water to generate phenolic hydroxyl group negative ions, can generate static electricity and other interaction with the cationic dye, and further contains the electropositive quaternary ammonium salt functional group, such that the strong interaction with the anionic dye can be provided so as to significantly improve the adsorption performance of the adsorbent on the anion and the cationic dye; therefore, the adsorbent has good practical application in printing and dyeing wastewater treatment.

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] In recent years, the textile printing and dyeing industry has developed rapidly, and a large amount of printing and dyeing wastewater has been generated. It contains more pollutants such as dyes, inorganic salts, and additives, and is one of the difficult-to-treat industrial wastewaters. At present, the methods for treating printing and dyeing wastewater are adsorption method, redox method, etc. The adsorption method has 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 resin has a porous structure and good adsorption performance, and is widely used in wastewater treatment. The Chinese patent with publication number CN117797783A discloses a modified polyaniline-loaded polystyrene adsorption resin and its preparation and application. With polystyrene resin as a carrier and polyaniline as a load material, aniline is polymerized in situ on the surface of polystyrene resin by a self-assembly method, and the obtained polystyrene adsorption resin has excellent adsorption effect on organic dyes. However, this patent can only adsorb anionic dyes such as methyl orange, and does not show good adsorption performance 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 the adsorption performance of polystyrene resin to anionic and cationic dyes is poor.

[0004] The technical solution of the present invention is a method for preparing an adsorbent for printing and dyeing wastewater: adding chloromethyl polystyrene resin to a solvent, stirring and swelling, then adding a triphenol 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 hydroxy 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: add 4-[(methylamino)methyl]phenol and glycerol triglycidyl ether to a reaction solvent of methanol, ethanol or tetrahydrofuran, heat to 40-55°C, react for 12-18h, rotary evaporate, wash with petroleum ether, dissolve the product in ethanol, heat evaporate, cool and crystallize to obtain the triphenolic hydroxy modifier. The reaction formula is:

[0009]

[0010] Further, 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 applied to adsorb cationic dyes and anionic dyes.

[0012] Technical effect: The present invention utilizes the tertiary amine group of the triphenolic hydroxyl modifier to carry out quaternization reaction with the chloromethyl group of the chloromethyl polystyrene resin to obtain an adsorbent for printing and dyeing wastewater, and the adsorbent contains hydrophilic groups such as ether bonds, quaternary ammonium salts, secondary hydroxyls and phenolic hydroxyls, which are beneficial to improving the hydrophilicity and water absorption rate of the adsorbent. It contains a large amount of phenolic hydroxyl groups, which are ionized in water to generate phenolic hydroxyl anions, which can interact with cationic dyes by electrostatics, and at the same time contain positively charged quaternary ammonium salt functional groups, which also have strong interactions with anionic dyes, and significantly improve the adsorption performance of the adsorbent to anionic and cationic dyes. The adsorbent has good practical application in the treatment of printing and dyeing wastewater. 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 described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0014] Example 1: (1) Add 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) to 50 mL of ethanol, heat to 50°C, react for 12 h, rotary evaporate, wash with petroleum ether, dissolve the product in ethanol, heat evaporate, cool and crystallize to obtain a triphenolic hydroxyl modifier.

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

[0016] Example 2: (1) Add 2 g of 4-[(methylamino)methyl]phenol and 6.6 g of propylene glycol triglycidyl ether to 50 mL of methanol, heat to 40°C, react for 18 h, rotary evaporate, wash with petroleum ether, dissolve the product in ethanol, heat evaporate, cool and crystallize to obtain a triphenolic hydroxyl modifier.

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

[0018] Example 3: (1) Add 2 g of 4-[(methylamino)methyl]phenol and 7.8 g of propylene glycol triglycidyl ether to 60 mL of tetrahydrofuran, heat to 55° C., react for 12 h, rotary evaporate, wash with petroleum ether, dissolve the product in ethanol, heat evaporate, cool and crystallize to obtain a triphenolic hydroxy modifier.

[0019] (2) Add 20 g of chloromethyl polystyrene resin to 250 mL of N,N-dimethylacetamide, stir to swell, then add 5 g of triphenol hydroxy 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.

[0020] Example 4: (1) Add 20 g of chloromethyl polystyrene resin to 300 mL of N,N-dimethylformamide, stir to 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 to 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 is used as an adsorbent for printing and dyeing wastewater.

[0023] Comparative Example 2: (1) Add 20 g of chloromethyl polystyrene resin to 200 mL of 1,2-dichloroethane, stir to swell, then add 1 g of N,N-dimethylbenzylamine (CAS registration number is 103-83-3), heat to 85°C, condense and reflux to react for 24 hours, filter, wash with ethanol and water in turn, and dry to obtain an adsorbent for printing and dyeing wastewater.

[0024] Comparative Example 3: (1) Add 20 g of chloromethyl polystyrene resin to 200 mL of 1,2-dichloroethane, stir to swell, then add 1 g of (dimethylaminomethyl)phenol (CAS registration number is 25338-55-0), heat to 85°C, condense and reflux to react for 24 hours, filter, wash with ethanol and water in turn, and dry to obtain an adsorbent for printing and dyeing wastewater.

[0025] Dry the adsorbent, weigh it, add it to distilled water and soak it for 24 hours, take out the adsorbent, absorb the surface water with filter paper, weigh it, and calculate the water absorption rate W. W = (m-m0) / m0×100%. m is the mass after water absorption. The mass before water absorption.

[0026] Table 1

[0027]

[0028]

[0029] It can be seen from Table 1 that compared with the chloromethyl polystyrene resin of Comparative Example 1, the polystyrene resin adsorbents of Examples 1-4 have higher hydrophilic groups 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 hydrophilicity and water absorption rate of the adsorbent being significantly lower than those of the embodiments.

[0031] Comparative Example 3 uses chloromethyl polystyrene resin and (dimethylaminomethyl)phenol to undergo quaternization reaction, and 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 being significantly lower than those of the embodiments.

[0032] Add 30 mg of adsorbent to 200 mL of methyl orange solution with a mass concentration of 50 mg / L, stir and adsorb for 3 hours at 25°C, centrifuge and take the upper liquid, test the absorbance and mass concentration of methyl orange in the solution by UV / visible spectrophotometer, and calculate the adsorption capacity. Q = (C0-C) × V / M. 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 Congo red solution with a mass concentration of 50 mg / L, stir and adsorb at 25°C for 4 hours, centrifuge and take the upper liquid, test the absorbance and mass concentration of methyl orange in the solution by UV / visible spectrophotometer, and calculate the adsorption capacity. Q = (C0-C) × V / M. 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 50 mg / L Rhodamine B solution, stir and adsorb at 25°C for 4 hours, centrifuge and take the upper layer of liquid, test the absorbance and mass concentration of methyl orange in the solution by UV / visible spectrophotometer, and calculate the adsorption capacity. Q = (C0-C) × V / M. 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 the comparative examples, the adsorbents of the embodiments all show 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 anions, which can interact with the cationic dyes electrostatically, and at the same time contain positively charged quaternary ammonium salt functional groups, which also have a strong interaction with the anionic dyes, 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 modifications may be made thereto 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 triphenol hydroxy 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: The preparation method of the triphenol hydroxy modifier is as follows: add 4-[(methylamino)methyl]phenol and glycerol triglycidyl ether into a reaction solvent, heat to 40-55° C., react for 12-18 hours, rotary evaporate, wash with petroleum ether, dissolve the product in ethanol, heat evaporate, cool and crystallize to obtain the triphenol hydroxy modifier.

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

7. The method for preparing an adsorbent for printing and dyeing wastewater according to claim 5, characterized in that: 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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