Regeneration process of clethodim sodium acetate wastewater adsorption resin

Abstract

The invention relates to the technical field of wastewater treatment, in particular to a regeneration process of clethodim sodium acetate wastewater adsorption resin. Comprising the following steps: step 1, washing macroporous resin with a first organic solvent; 2, carrying out ultrasonic washing by using a second organic solvent; 3, washing with a first organic solvent; and 4, washing with water, drying, and carrying out carbonization treatment to obtain the product. The macroporous resin is washed by the first organic solvent, then ultrasonically washed by the second organic solvent and then washed by the first organic solvent, so that organic impurities can be efficiently removed; when the first organic solvent is methanol, the washing flow rate is 1-4BV / h and the washing time is 0.5-2 hours, the swelling of a high-molecular compound in the macroporous resin can be reduced, meanwhile, the organic impurities are permeated, and the adsorption performance of the macroporous resin is maintained; the drying temperature is 80-150 DEG C, the drying time is 1-4 hours, the deformation of the resin can be avoided, and the physical and chemical stability of the resin can be maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, in particular to the field of IPC C02F9, and more specifically to a regeneration process of sodium clethodim acetate wastewater adsorption resin. Background Art

[0002] Clethodim is an inhibitor and a systemic stem and leaf treatment herbicide with excellent selectivity, strong killing effect on grass weeds, and safe for dicotyledonous crops. The heptylene process in the production of Clethodim produces a large amount of sodium acetate wastewater, and the sodium acetate wastewater is dark in color. The sodium acetate trihydrate directly recovered by evaporation and crystallization is black in color and cannot meet the commodity requirements for sale. Usually, after adsorption treatment with a macroporous resin column, white sodium acetate trihydrate is obtained by evaporation and crystallization, which meets the industrial grade sodium acetate trihydrate standard. It can be sold as a commodity. Among them, macroporous adsorption resin is a type of polymer adsorption resin with a macroporous structure, which has a good macroporous network structure and a large specific surface area, and can selectively adsorb organic matter in aqueous solution. It is used as an adsorption decolorizer in the treatment of clethodim sodium acetate wastewater. After being saturated with organic impurities, the macroporous adsorption resin is regenerated by methanol elution. The regenerated macroporous adsorption resin can restore its adsorption capacity; however, the number of times the resin can be regenerated is limited. When the resin cannot restore its effective adsorption performance through regeneration, it reaches the end of its service life and is transferred as hazardous waste. Effective regeneration of these discarded macroporous adsorption resins can not only improve the service life of the resin but also reduce the investment cost of the resin.

[0003] Chinese invention patent CN101024163A discloses a method for introducing surface functional groups to enhance the regeneration performance of adsorption resins. This invention does not affect the adsorption performance, but enhances the regeneration performance of adsorption resins, thereby reducing the amount of desorbent used, lowering the desorption temperature, and saving operating costs. It is of great significance for the application and promotion of resin adsorption technology. However, this method is costly and complex, and cannot be used to treat waste adsorption resins. Summary of the invention

[0004] The present invention provides a regeneration process for sodium clethodim acetate wastewater adsorption resin, comprising the following steps:

[0005] Step 1: washing the macroporous resin with a first organic solvent;

[0006] Step 2: ultrasonically washing with a second organic solvent;

[0007] Step 3: washing with the first organic solvent;

[0008] Step 4: After washing with water and drying, carbonization treatment is performed to obtain the product.

[0009] The applicant has found that the macroporous resin can be efficiently removed from organic impurities by washing with a first organic solvent, then ultrasonically washing with a second organic solvent, and then washing with the first organic solvent. It is possible that the first organic solvent washing can remove the permeated organic impurities, especially when the first organic solvent is methanol, the washing flow rate is 1-4BV / h, and the time is 0.5-2h. While reducing the swelling of the polymer compounds in the macroporous resin, the organic impurities can be permeated to maintain the adsorption performance of the macroporous resin. For impurities such as tar adsorbed on the macroporous resin, after being washed and penetrated with the first solvent, they can be effectively removed by ultrasonic washing with the second organic solvent. Washing with the first organic solvent again can effectively remove strong polar substances such as dimethyl sulfoxide, thereby avoiding further swelling of the resin and reducing the adsorption performance of the resin.

[0010] The drying temperature is 80-150° C. and the drying time is 1-4 hours.

[0011] Preferably, the drying temperature is 100-120° C. and the drying time is 1-3 hours.

[0012] More preferably, the drying temperature is 100-110° C. and the drying time is 1-2 h.

[0013] The applicant has found that the drying temperature is 80-150°C and the time is 1-4h, which can avoid deformation of the resin and maintain its physical and chemical stability. Macroporous resin has a higher porosity and a larger pore size in a dry state. These characteristics enable it to exhibit excellent performance in the adsorption and separation process. After adsorbing water, its pores are occupied by water. The drying temperature directly affects the physical and chemical stability of the macroporous resin. Appropriate drying temperature can maintain the structural integrity of the macroporous resin and avoid resin cracking or deformation due to excessive drying. However, too high a drying temperature may cause the pore structure of the resin to collapse, thereby reducing its specific surface area and adsorption capacity. In addition, the drying temperature will also affect the hydrophobicity and hydrophilicity of the resin, thereby affecting its adsorption selectivity for different substances.

[0014] The carbonization treatment specifically includes: setting the carbonization temperature, program heating to the carbonization temperature, keeping the temperature, and cooling down.

[0015] The carbonization temperature is 350-500°C.

[0016] Preferably, the carbonization temperature is 380-420°C.

[0017] Further preferably, the carbonization temperature is 380-400°C.

[0018] Most of the organic impurities can be removed by washing in steps 1-3, but some stubborn stains are still difficult to remove. If the washing time or washing steps are extended, the pore structure of the macroporous resin may be affected, resulting in a decrease in the selective adsorption of the resin. The applicant has found that through programmed temperature carbonization treatment, the carbonization temperature is 350-500°C, and the programmed temperature time is 3-5h. The organic stubborn stains attached to the surface of the macroporous resin can be removed, and the degree of recovery of the physical and chemical properties is close to that of a new macroporous resin, which meets the use requirements of sodium acetate wastewater. However, if the carbonization temperature is too high or the heating rate is too fast, the skeleton structure of the macroporous resin may be affected, resulting in a poor resin utilization rate.

[0019] Further research found that the carbonization temperature is 380-420°C and the programmed heating time is 3-4h, which can improve the mechanical properties of the resin and meet the use requirements in various decolorization fields. It may be that after carbonization treatment at a specific temperature, the heat transfer efficiency on the surface of the macroporous resin and inside the nanopores is improved, and the internal stress of the resin is reduced, so that the carbonized resin can interact with the target substance through electrostatic effects, van der Waals forces, hydrogen bonds and other forces, thereby achieving selective adsorption of the target substance.

[0020] The time of the programmed temperature rise is 3-5h.

[0021] Preferably, the time of the programmed temperature rise is 3-4 h.

[0022] Further preferably, the time of the programmed temperature rise is 3.5-4h.

[0023] The first organic solvent includes at least one of ethylene dichloride, methanol, acetone, ethanol, and toluene.

[0024] Preferably, the first organic solvent includes at least one of ethylene dichloride, methanol and acetone.

[0025] Further preferably, the first organic solvent comprises methanol.

[0026] The second organic solvent includes at least one of methanol, ethanol, dimethyl sulfoxide, and N,N-dimethylformamide.

[0027] Preferably, the second organic solvent includes at least one of ethanol, dimethyl sulfoxide and N,N-dimethylformamide.

[0028] Further preferably, the second organic solvent comprises dimethyl sulfoxide.

[0029] The flushing flow rate in step 1 is 1-4 BV / h, and the flushing time is 0.5-2h.

[0030] Preferably, the flushing flow rate in step 1 is 1-3 BV / h and the flushing time is 0.5-1.5h.

[0031] Further preferably, the flushing flow rate in step 1 is 1-2 BV / h and the flushing time is 1-1.5 h.

[0032] The weight ratio of the macroporous resin to the second organic solvent is 1:(1-4).

[0033] Preferably, the weight ratio of the macroporous resin to the second organic solvent is 1:(1-3).

[0034] Further preferably, the weight ratio of the macroporous resin to the second organic solvent is 1:(1-2).

[0035] The ultrasonic washing time is 0.1-1h.

[0036] Preferably, the ultrasonic washing time is 0.2-1h.

[0037] Further preferably, the ultrasonic washing time is 0.3-0.7h.

[0038] Beneficial Effects

[0039] 1. The macroporous resin is washed with a first organic solvent, then ultrasonically washed with a second organic solvent, and then washed with the first organic solvent, so that organic impurities can be removed efficiently.

[0040] 2. When the first organic solvent is methanol and the flushing flow rate is 1-4 BV / h and the time is 0.5-2h, the organic impurities can be penetrated while reducing the swelling of the polymer compound in the macroporous resin, thereby maintaining the adsorption performance of the macroporous resin.

[0041] 3. The drying temperature is 80-150°C and the drying time is 1-4 hours, which can avoid deformation of the resin and maintain its physical and chemical stability.

[0042] 4. Through programmed temperature carbonization treatment, the carbonization temperature is 350-500℃, and the programmed temperature time is 3-5h, the organic stubborn stains attached to the surface of the macroporous resin can be removed, and the degree of recovery of physical and chemical properties is close to that of a new macroporous resin, meeting the use requirements of sodium clethodim acetate wastewater.

[0043] 5. The carbonization temperature is 380-420°C, and the programmed temperature rise time is 3-4h, which can improve the mechanical properties of the resin and meet the use requirements in various decolorization fields. DETAILED DESCRIPTION

[0044] The scrapped resin used in the following examples is the macroporous adsorption resin RD-100 macroporous adsorption resin (polystyrene copolymer) used in the treatment of sodium clethodim acetate wastewater.

[0045] Example 1

[0046] A regeneration process for sodium clethodim acetate wastewater adsorption resin comprises the following steps:

[0047] After the scrapped resin is washed with methanol at a flow rate of 2BV / h for 1 hour through the resin column, the washed resin is taken to the laboratory, 50mL of resin is measured and placed in a 250mL beaker, 100mL of dimethyl sulfoxide (2BV dosage) is added, and the solution turns black after washing with an ultrasonic cleaner for 30 minutes. Then filter, transfer the resin to a 250mL beaker and wash it with methanol twice (100mL methanol each time), then wash it with water once and dry it, put it in a drying oven after drying for 2 hours (drying temperature is 110℃), put it in a muffle furnace for carbonization treatment after drying, and the muffle furnace is set to 390℃, the program heating time is 4h, and the 390℃ holding time is 1h. After cooling, a black carbonized resin is obtained.

[0048] Example 2

[0049] A regeneration process for sodium clethodim acetate wastewater adsorption resin comprises the following steps:

[0050] After the scrapped resin is washed with methanol at a flow rate of 2BV / h for 1 hour through the resin column, the washed resin is taken to the laboratory, 50mL of resin is measured and placed in a 250mL beaker, 100mL of dimethyl sulfoxide (2BV dosage) is added, and the solution turns black after washing with an ultrasonic cleaner for 30 minutes. Then filter, transfer the resin to a 250mL beaker and wash it with methanol twice (100mL methanol each time), then wash it with water once and dry it, put it in a drying oven for 2 hours (drying temperature is 100℃), and put it in a muffle furnace for carbonization treatment after drying. The muffle furnace is set to 400℃, the program heating time is 4h, and the 400℃ holding time is 1h. After cooling, a black carbonized resin is obtained.

[0051] Comparative Example 1

[0052] A regeneration process for sodium clethodim acetate wastewater adsorption resin comprises the following steps:

[0053] After the scrapped resin is washed with methanol at a flow rate of 2BV / h for 1 hour through the resin column, the washed resin is taken to the laboratory, 50mL of resin is measured and placed in a 250mL beaker, 100mL of dimethyl sulfoxide (2BV dosage) is added, and the solution turns black after washing in an ultrasonic cleaner for 30 minutes. Then filter, transfer the resin to a 250mL beaker and wash it with methanol twice (100mL methanol each time), then wash it with water once and dry it, put it in a drying oven for 2 hours after drying (drying temperature is 110℃), put it in a muffle furnace for carbonization treatment after drying, and the muffle furnace is set to 500℃, the program heating time is 4h, and the 500℃ holding time is 1h. After cooling down, open the muffle furnace.

[0054] Comparative Example 2

[0055] A regeneration process for sodium clethodim acetate wastewater adsorption resin comprises the following steps:

[0056] After the scrapped resin was washed with methanol at a flow rate of 2BV / h for 1 hour through the resin column, the washed resin was taken to the laboratory, 50mL of resin was measured and placed in a 250mL beaker, 100mL of dimethyl sulfoxide (2BV dosage) was added, and the solution turned black after washing with an ultrasonic cleaner for 30 minutes. Then filter, transfer the resin to a 250mL beaker and wash it with methanol twice (100mL of methanol each time), then wash it with water once and dry it, and then put it into a drying oven for drying for 2 hours (drying temperature is 70℃), and put it into a muffle furnace for carbonization treatment after drying. The muffle furnace is set to 390℃, the program heating time is 4h, and the 390℃ holding time is 1h.

[0057] Performance testing methods and data

[0058] The performance tests were carried out in the embodiments and comparative examples, and the test data are listed in Table 1, wherein “-” indicates that the test was not carried out.

[0059] 1. Observe the morphology of carbonized resin with naked eyes.

[0060] 2. Sodium acetate wastewater treatment rate test: Use a gradually increasing flow rate to test the sodium acetate wastewater treatment. The rate at which sodium acetate trihydrate is pure white after treatment and crystallization is recorded as the sodium acetate wastewater treatment rate. The purchased new resin is used as an experimental control, RD-100 macroporous adsorption resin (polystyrene copolymer).

[0061] A specific test was conducted using Example 1: 50 mL of carbonized resin was added to the resin column (1). Sodium acetate wastewater was passed through the column at a flow rate of 2 BV / h (100 mL / h). 3 BV (150 mL) of the effluent was sampled and distilled for salt. After distillation and crystallization, sodium acetate trihydrate was pure white. (2). Sodium acetate wastewater was passed through the column at a flow rate of 3 BV / h (150 mL / h). 3 BV (150 mL) of the effluent was sampled and distilled for salt. After distillation and crystallization, sodium acetate trihydrate was pure white. (3). Sodium acetate wastewater was passed through the column at a flow rate of 5 BV / h (250 mL / h). 3 BV (150 mL) of the effluent was sampled and distilled for salt. After distillation and crystallization, sodium acetate trihydrate was pure white. (4) Sodium acetate wastewater is passed through the column at a flow rate of 8BV / h (400mL / h), and the effluent is sampled and evaporated every 3BV (150mL). After distillation and crystallization, the sodium acetate trihydrate is pure white. (5) Sodium acetate wastewater is passed through the column at a flow rate of 10BV / h (500mL / h), and the effluent is sampled and evaporated every 3BV (150mL). After distillation and crystallization, the color of sodium acetate trihydrate is light yellow. The maximum carbonization rate is 8BV.

[0062] 3. Decolorization rate of oxyfluorfen solution: Use a gradually increasing flow rate to decolorize the oxyfluorfen toluene solution. The maximum rate at which the chromaticity after treatment is less than 6 is recorded as the decolorization rate of the oxyfluorfen solution. Use a purchased new resin for experimental control.

[0063] A specific test was conducted using Example 1: 50 mL of carbonized resin was added to the resin column (1), and the oxyfluorfen toluene solution with a chromaticity of 10.3 was passed through the column at a flow rate of 2 BV / h (100 mL / h). After adsorption, the solution was sampled and the chromaticity was 4.1. (2), the oxyfluorfen toluene solution with a chromaticity of 10.3 was passed through the column at a flow rate of 3 BV / h (150 mL / h). After adsorption, the solution was sampled and the chromaticity was 4.1. (3), the oxyfluorfen toluene solution with a chromaticity of 10.3 was passed through the column at a flow rate of 5 BV / h (250 mL / h). After adsorption, the solution was sampled and the chromaticity was 4.5. (4), the oxyfluorfen toluene solution with a chromaticity of 10.3 was passed through the column at a flow rate of 8 BV / h (400 mL / h). After adsorption, the solution was sampled and the chromaticity was 4.8. (5) The oxyfluorfen toluene solution with a chromaticity of 10.3 was passed through the column at a flow rate of 10 BV / h (500 mL / h). After adsorption, the solution was sampled and the chromaticity was 5.5. (6) The oxyfluorfen toluene solution with a chromaticity of 10.3 was passed through the column at a flow rate of 12 BV / h (600 mL / h). After adsorption, the solution was sampled and the chromaticity was 6.2. (Higher than our chromaticity requirement (chromaticity < 6)). The treatment resin can be used at a rate of 10 times.

[0064] Table 1

[0065]

Claims

1. A regeneration process for sodium clethodim acetate wastewater adsorption resin, characterized in that: The following steps are involved: Step 1: washing the macroporous resin with a first organic solvent; Step 2: ultrasonic washing using a second organic solvent; Step 3: washing with a first organic solvent; Step 4: After washing with water and drying, carbonization treatment is performed to obtain the product.

2. The regeneration process of sodium clethodim acetate wastewater adsorption resin according to claim 1, characterized in that: The drying temperature is 80-150° C. and the drying time is 1-4 hours.

3. The regeneration process of sodium clethodim acetate wastewater adsorption resin according to claim 2, characterized in that: The carbonization treatment specifically includes: setting the carbonization temperature, program heating to the carbonization temperature, keeping the temperature, and cooling down.

4. The regeneration process of sodium clethodim acetate wastewater adsorption resin according to claim 3, characterized in that: The carbonization temperature is 350-500°C.

5. The regeneration process of sodium clethodim acetate wastewater adsorption resin according to claim 4, characterized in that: The time of the programmed temperature rise is 3-5h.

6. The regeneration process of sodium clethodim acetate wastewater adsorption resin according to claim 5, characterized in that: The first organic solvent includes at least one of ethylene dichloride, methanol, acetone, ethanol, and toluene.

7. The regeneration process of sodium clethodim acetate wastewater adsorption resin according to claim 1 or 6, characterized in that: The second organic solvent includes at least one of methanol, ethanol, dimethyl sulfoxide, and N,N-dimethylformamide.

8. The regeneration process of sodium clethodim acetate wastewater adsorption resin according to claim 7, characterized in that: The flushing flow rate in step 1 is 1-4 BV / h, and the flushing time is 0.5-2h.

9. The regeneration process of sodium clethodim acetate wastewater adsorption resin according to claim 8, characterized in that: The weight ratio of the macroporous resin to the second organic solvent is 1:(1-4).

10. The regeneration process of sodium clethodim acetate wastewater adsorption resin according to claim 9, characterized in that: The ultrasonic washing time is 0.1-1h.

Images