A method for extracting sodium glycolate from pesticide wastewater

Abstract

The application discloses a method for extracting sodium glycolate from pesticide wastewater and belongs to the wastewater treatment field. After 2,4-D production wastewater is stirred after pH is adjusted to 3.0, the filtrate is collected by filtration, the pH of the filtrate is adjusted to 8.0, and the concentrated solution is obtained by concentration under reduced pressure. The concentrated solution, modified cyclodextrin and modified cellulose are mixed according to the weight ratio of 100:0.8-1.2:0.1-0.3, the first mixing and stirring are performed, the second mixing and stirring are performed after cooling, the third mixing and stirring are performed after cooling again, and the filter cake is collected. After the filter cake and deionized water are mixed and stirred, the filtrate is collected by filtration, and the sodium glycolate is obtained by vacuum drying of the filtrate. The application solves the problem of co-crystallization of sodium glycolate and sodium chloride, and improves the purity and yield of sodium glycolate.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, and more specifically to a method for extracting sodium glycolate from pesticide wastewater. Background Technology

[0002] The production of 2,4-D pesticides generates a large amount of industrial wastewater containing recyclable chemical components such as sodium glycolate and sodium chloride. Direct discharge of this wastewater not only pollutes surrounding water bodies and the ecological environment but also results in the loss of valuable raw materials. Therefore, the resource recovery and utilization of this type of wastewater is an inevitable trend for the green development of the pesticide industry. Currently, the industry mainly uses the traditional cooling crystallization process to recover sodium glycolate. This process relies on the difference in solubility of different substances with temperature to achieve component separation. Because sodium glycolate and sodium chloride have similar solubility characteristics, they are prone to co-crystallization during cooling, and the purity of the product obtained from a single crystallization is difficult to meet industrial standards. Multiple recrystallizations are usually used for purification in production. This operation not only prolongs the production process, increases equipment investment and energy consumption, but also causes material loss, resulting in a low final recovery rate of sodium glycolate. The traditional crystallization process has significant drawbacks.

[0003] To address the aforementioned issues, the industry has attempted improvements by optimizing pretreatment processes and adjusting crystallization parameters. However, simplifying wastewater pretreatment can lead to residual organic impurities and incompletely removed salts directly interfering with the crystallization process and further reducing product quality. Simply adjusting cooling rates and temperature ranges cannot fundamentally solve the co-crystallization problem; it only slightly improves separation efficiency. Currently, all conventional improvement methods have shortcomings. In high-salinity wastewater environments, it is difficult to simultaneously achieve product purity, material yield, and production efficiency. The overall process stability is poor, failing to meet the industrial application requirements for efficient resource recovery of pesticide wastewater.

[0004] Invention patent CN115710175A discloses a method for recovering sodium glycolate from 2,4-D wastewater. This process requires multiple steps, including evaporation and concentration, decolorization, crystallization, acidification, esterification, distillation, and hydrolysis. The process is cumbersome, requires extensive equipment, and has low industrial production efficiency. It consumes large amounts of raw materials such as hydrochloric acid and methanol, and the high energy consumption from high-temperature evaporation and multi-step reactions results in high production costs. Furthermore, the product yield is low, the effective components in the wastewater are not fully recovered, and the problem of co-crystallization of sodium glycolate and sodium chloride is not solved. The product is obtained indirectly through chemical conversion, and multiple purification steps are required to ensure purity. Overall, the production cycle is long and the economics are poor.

[0005] Therefore, providing a method for efficiently recovering high-purity sodium glycolate from 2,4-D pesticide wastewater is an important problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the problem in the existing technology of recovering sodium glycolate from 2,4-D pesticide wastewater, where sodium glycolate and sodium chloride easily co-crystallize, resulting in low purity of the sodium glycolate product, this invention provides a method for extracting sodium glycolate from pesticide wastewater.

[0007] Specifically, the technical solution of the present invention includes the following: A method for extracting sodium glycolate from pesticide wastewater, the method comprising the following steps: After adjusting the pH of the 2,4-D production wastewater to 3.0 and stirring, the filtrate was collected by filtration. The pH of the filtrate was then adjusted to 8.0 and concentrated under reduced pressure to obtain a concentrated solution. The concentrate, modified cyclodextrin and modified cellulose are mixed at a weight ratio of 100:0.8~1.2:0.1~0.3. After the first mixing and stirring, the mixture is cooled and then mixed and stirred a second time. After cooling again and then mixing and stirring a third time, the filter cake is collected. After mixing and stirring the filter cake and deionized water, the filtrate was collected by filtration and then dried under vacuum to obtain sodium glycolate. The preparation method of the modified cyclodextrin includes the following steps: β-Cyclodextrin, sodium hydroxide, and chloroacetic acid were mixed and stirred in a weight ratio of 10:2.5~3.0:5.5~6.5 to obtain carboxymethyl cyclodextrin. Carboxymethyl cyclodextrin, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide and ethylenediamine were mixed and stirred in a weight ratio of 10:0.5~0.8:0.2~0.5:1.2~1.8 to obtain carboxy-amino functionalized cyclodextrin. Carboxy-amino functionalized cyclodextrin, D-glucanolactone, and triethylamine were mixed and stirred in a weight ratio of 10:0.2~0.4:0.4~0.6 to obtain multi-functionalized cyclodextrin. Modified cyclodextrin was obtained by mixing and stirring poly-functional cyclodextrin and calcium chloride at a weight ratio of 10:0.5~0.9.

[0008] Furthermore, the conditions for adjusting the pH to 3.0 and stirring include a stirring speed of 200 r / min and a stirring time of 10 min.

[0009] Furthermore, the concentrated solution contains 40% sodium glycolate.

[0010] Furthermore, the reaction conditions for the mixture of β-cyclodextrin, sodium hydroxide, and chloroacetic acid include a reaction pH of 10-11, a reaction temperature of 45-55°C, and a reaction time of 3.5-4.5 h.

[0011] Furthermore, the conditions for the mixed and stirred reaction of the carboxymethyl cyclodextrin, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide and ethylenediamine include a reaction pH of 5-6, a reaction temperature of 34-38°C and a reaction time of 18-20 h.

[0012] Furthermore, the conditions for the mixed stirring reaction of the carboxyl-amino functionalized cyclodextrin, D-glucosidase and triethylamine include a reaction pH of 7-8, a reaction temperature of 34-45°C, and a reaction time of 8-10 h.

[0013] Furthermore, the conditions for the mixed stirring reaction of the multi-group cyclodextrin and calcium chloride include a reaction pH of 7-8, a reaction temperature of 50-60°C, and a reaction time of 50-80 min.

[0014] Furthermore, the method for preparing the modified cellulose includes the following steps: Microcrystalline cellulose, ammonium dihydrogen phosphate, and urea were mixed and stirred in a weight ratio of 10:4.2~4.5:0.8~1.2 to obtain phosphorylated cellulose. Modified cellulose was obtained by mixing and stirring phosphorylated cellulose, sodium 2-chloroethane sulfonate and sodium hydroxide in a weight ratio of 10:1.6~2.0:0.8~1.2.

[0015] Furthermore, the conditions for the mixing and stirring reaction of the microcrystalline cellulose, ammonium dihydrogen phosphate and urea include a reaction temperature of 60-70°C and a reaction time of 2-3 hours.

[0016] Furthermore, the conditions for the mixed and stirred reaction of cellulose phosphorylated, sodium 2-chloroethane sulfonate, and sodium hydroxide include a reaction temperature of 85-95°C and a reaction time of 12-14 hours.

[0017] Furthermore, the conditions for the first mixing and stirring include a stirring temperature of 90~96℃, a stirring speed of 200r / min, and a stirring time of 20~30min.

[0018] Furthermore, the conditions for the second mixing and stirring include a stirring temperature of 40~50℃, a stirring speed of 200r / min, and a stirring time of 40~60min.

[0019] Furthermore, the conditions for the third mixing and stirring include a stirring temperature of 15~18℃, a stirring speed of 150r / min, and a stirring time of 2~3h.

[0020] Furthermore, the weight ratio of the filter cake to deionized water is 1:0.5.

[0021] Furthermore, the conditions for mixing and stirring the filter cake and deionized water include a stirring speed of 100 r / min and a stirring time of 30 to 50 min.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention uses a combination of modified cyclodextrin and modified cellulose to achieve efficient extraction of sodium glycolate from 2,4-D pesticide wastewater. After multi-step modification, modified cyclodextrin can recognize sodium glycolate through intermolecular interactions, reducing the co-crystallization of sodium chloride and sodium glycolate and improving the purity of the crystallized product. However, it is prone to agglomeration and sedimentation in high-salt concentrate systems, which will reduce the system's dispersion uniformity, causing uneven sodium glycolate nucleation rate. It may also affect the purity and yield of the final product due to impurities encapsulated by agglomeration. The modified cellulose used in this invention is made from microcrystalline cellulose. Its surface phosphate groups can form a weak coordination with modified cyclodextrin, inhibiting the aggregation and sedimentation of modified cyclodextrin. At the same time, its own functional groups can improve the system's salt resistance and dispersion. The fibrous structure can also serve as a dispersion carrier, allowing the modified cyclodextrin to be evenly distributed in the system, improving the impurity encapsulation problem caused by agglomeration, and enabling sodium glycolate to nucleate evenly and grow stably.

[0023] (2) The two materials in this invention can form a synergistic effect to optimize the extraction process of sodium glycolate. This process does not require multiple recrystallization operations; extraction can be completed in a single crystallization and filtration step, simplifying the process and reducing production energy consumption. Modified cyclodextrin and modified cellulose can be recovered through dissolution and separation, and can be recycled. The wastewater mother liquor can also be returned to the concentration process for continued use. This compound system has good tolerance to wastewater systems with high salt content and trace impurities, and does not require complex pretreatment steps, making it suitable for industrial applications. The synergistic effect between the materials can maintain the dispersion stability of the system, ensure the continuous function of modified cyclodextrin, regulate the crystallization process of sodium glycolate, reduce impurity entrainment, and achieve efficient separation of the product and functional materials based on solubility differences, thereby improving the stability of process operation, ensuring the purity and yield of sodium glycolate, and completing the resource-based treatment of 2,4-D pesticide wastewater. Detailed Implementation

[0024] The technical solution of the present invention will be clearly and completely described below through embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Unless otherwise stated, all raw materials and reagents used in this invention are commercially available or can be prepared by known methods.

[0026] Preparation Example 1 The preparation method of modified cyclodextrin includes the following steps: 10 parts by weight of β-cyclodextrin and 2.5 parts by weight of sodium hydroxide were dispersed in 100 parts by weight of deionized water and stirred at 200 r / min for 10 min. 5.5 parts by weight of chloroacetic acid were added to adjust the pH to 10. The temperature was raised to 45℃ and the reaction was stirred for 3.5 h. After the reaction was completed, the temperature was cooled to 26℃ and the pH was adjusted to 7.0. 5 times the volume of methanol of the reaction solution was added. The precipitate was collected by centrifugation at 8000 r / min for 10 min. The precipitate was washed 3 times with deionized water and then dried under vacuum at 60℃ for 10 h to obtain carboxymethyl cyclodextrin. Ten parts by weight of carboxymethyl cyclodextrin were dispersed in 200 parts by weight of anhydrous dimethyl sulfoxide. After stirring and dispersing at 150 r / min for 10 min, 0.5 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, 0.2 parts by weight of N-hydroxysuccinimide and 1.2 parts by weight of ethylenediamine were added. The pH was adjusted to 5, and the temperature was raised to 34 °C under a nitrogen atmosphere. The reaction was stirred for 18 h. After the reaction was completed, the temperature was cooled to 26 °C, and five times the volume of anhydrous ethanol was added. The precipitate was collected by centrifugation at 8000 r / min for 10 min. After washing three times with deionized water, the precipitate was dried under vacuum at 60 °C for 10 h to obtain carboxy-amino functionalized cyclodextrin. Ten parts by weight of carboxyl-amino functionalized cyclodextrin were dispersed in 80 parts by weight of anhydrous methanol. After stirring at 200 r / min for 10 min, 0.2 parts by weight of D-gluconic acid lactone and 0.4 parts by weight of triethylamine were added, the pH was adjusted to 7, the temperature was raised to 35℃ and the reaction was stirred for 8 h. After the reaction was completed, the temperature was cooled to 26℃, and five times the volume of anhydrous ethanol was added. The precipitate was collected by centrifugation at 8000 r / min for 10 min, washed three times with anhydrous ethanol, and dried under vacuum at 50℃ for 12 h to obtain multi-group cyclodextrin. Ten parts by weight of polycyclic cyclodextrin were dispersed in 100 parts by weight of deionized water. After stirring at 180 r / min for 10 min, 0.5 parts by weight of calcium chloride were added to adjust the pH to 7. The mixture was stirred at 50 °C for another 50 min. After the reaction was completed, the mixture was cooled to 26 °C, and three times the volume of anhydrous ethanol was added. After standing for 3 h, the precipitate was collected by centrifugation at 6000 r / min for 10 min. The precipitate was washed three times with deionized water and then vacuum dried at 50 °C for 10 h to obtain modified cyclodextrin.

[0027] Preparation Example 2 The preparation method of modified cyclodextrin includes the following steps: 10 parts by weight of β-cyclodextrin and 2.6 parts by weight of sodium hydroxide were dispersed in 100 parts by weight of deionized water and stirred at 220 r / min for 11 min. 5.8 parts by weight of chloroacetic acid were added to adjust the pH to 10.2. The temperature was raised to 47 °C and the reaction was stirred for 3.8 h. After the reaction was completed, the temperature was cooled to 26 °C and the pH was adjusted to 7.0. 5 times the volume of methanol of the reaction solution was added. The precipitate was collected by centrifugation at 8000 r / min for 10 min. The precipitate was washed 3 times with deionized water and then dried under vacuum at 60 °C for 10 h to obtain carboxymethyl cyclodextrin. Ten parts by weight of carboxymethyl cyclodextrin were dispersed in 200 parts by weight of anhydrous dimethyl sulfoxide. After stirring at 180 r / min for 13 min, 0.6 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, 0.3 parts by weight of N-hydroxysuccinimide and 1.4 parts by weight of ethylenediamine were added. The pH was adjusted to 5.3. The mixture was heated to 35 °C under a nitrogen atmosphere and stirred for 18.5 h. After the reaction was completed, the mixture was cooled to 26 °C. Five times the volume of anhydrous ethanol was added to the reaction mixture. The precipitate was collected by centrifugation at 8000 r / min for 10 min. The precipitate was washed three times with deionized water and then dried under vacuum at 60 °C for 10 h to obtain carboxy-amino functionalized cyclodextrin. Ten parts by weight of carboxyl-amino functionalized cyclodextrin were dispersed in 80 parts by weight of anhydrous methanol. After stirring at 220 r / min for 13 min, 0.25 parts by weight of D-gluconic acid lactone and 0.45 parts by weight of triethylamine were added, the pH was adjusted to 7.2, the temperature was raised to 38℃ and the reaction was stirred for 8.5 h. After the reaction was completed, the temperature was cooled to 26℃, and five times the volume of anhydrous ethanol was added. The precipitate was collected by centrifugation at 8000 r / min for 10 min, washed three times with anhydrous ethanol, and dried under vacuum at 50℃ for 12 h to obtain multi-group cyclodextrin. Ten parts by weight of polycyclic cyclodextrin were dispersed in 100 parts by weight of deionized water. After stirring at 200 r / min for 12 min, 0.6 parts by weight of calcium chloride were added to adjust the pH to 7.2. The reaction was continued at 53 °C for 60 min. After the reaction was completed, the mixture was cooled to 26 °C, and three times the volume of anhydrous ethanol was added. After standing for 3 h, the precipitate was collected by centrifugation at 6000 r / min for 10 min. The precipitate was washed three times with deionized water and then vacuum dried at 50 °C for 10 h to obtain modified cyclodextrin.

[0028] Preparation Example 3 The preparation method of modified cyclodextrin includes the following steps: 10 parts by weight of β-cyclodextrin and 2.7 parts by weight of sodium hydroxide were dispersed in 100 parts by weight of deionized water and stirred at 250 r / min for 12 min. 6.0 parts by weight of chloroacetic acid were added to adjust the pH to 10.5. The temperature was raised to 50 °C and the reaction was stirred for 4 h. After the reaction was completed, the temperature was cooled to 26 °C and the pH was adjusted to 7.0. 5 times the volume of methanol of the reaction solution was added. The precipitate was collected by centrifugation at 8000 r / min for 10 min. The precipitate was washed 3 times with deionized water and then dried under vacuum at 60 °C for 10 h to obtain carboxymethyl cyclodextrin. Ten parts by weight of carboxymethyl cyclodextrin were dispersed in 200 parts by weight of anhydrous dimethyl sulfoxide. After stirring at 200 r / min for 15 min, 0.65 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, 0.35 parts by weight of N-hydroxysuccinimide and 1.5 parts by weight of ethylenediamine were added. The pH was adjusted to 5.5, and the mixture was heated to 36 °C under a nitrogen atmosphere and stirred for 19 h. After the reaction was completed, the mixture was cooled to 26 °C, and five times the volume of anhydrous ethanol was added. The precipitate was collected by centrifugation at 8000 r / min for 10 min. After washing three times with deionized water, the precipitate was dried under vacuum at 60 °C for 10 h to obtain carboxy-amino functionalized cyclodextrin. Ten parts by weight of carboxyl-amino functionalized cyclodextrin were dispersed in 80 parts by weight of anhydrous methanol. After stirring at 240 r / min for 15 min, 0.3 parts by weight of D-gluconic acid lactone and 0.5 parts by weight of triethylamine were added, the pH was adjusted to 7.5, the temperature was raised to 40℃ and the reaction was stirred for 9 h. After the reaction was completed, the temperature was cooled to 26℃, and 5 times the volume of anhydrous ethanol was added. The precipitate was collected by centrifugation at 8000 r / min for 10 min, washed 3 times with anhydrous ethanol, and dried under vacuum at 50℃ for 12 h to obtain multi-group cyclodextrin. Ten parts by weight of polydextrin were dispersed in 100 parts by weight of deionized water. After stirring at 215 r / min for 13 min, 0.7 parts by weight of calcium chloride were added to adjust the pH to 7.5. The reaction was continued at 55 °C for 65 min. After the reaction was completed, the mixture was cooled to 26 °C, and three times the volume of anhydrous ethanol was added. After standing for 3 h, the precipitate was collected by centrifugation at 6000 r / min for 10 min. The precipitate was washed three times with deionized water and then vacuum dried at 50 °C for 10 h to obtain modified cyclodextrin.

[0029] Preparation Example 4 The preparation method of modified cyclodextrin includes the following steps: 10 parts by weight of β-cyclodextrin and 2.8 parts by weight of sodium hydroxide were dispersed in 100 parts by weight of deionized water and stirred at 270 r / min for 14 min. 6.2 parts by weight of chloroacetic acid were added to adjust the pH to 10.7. The temperature was raised to 52 °C and the reaction was stirred for 4.2 h. After the reaction was completed, the temperature was cooled to 26 °C and the pH was adjusted to 7.0. 5 times the volume of methanol of the reaction solution was added. The precipitate was collected by centrifugation at 8000 r / min for 10 min. The precipitate was washed 3 times with deionized water and then dried under vacuum at 60 °C for 10 h to obtain carboxymethyl cyclodextrin. Ten parts by weight of carboxymethyl cyclodextrin were dispersed in 200 parts by weight of anhydrous dimethyl sulfoxide. After stirring at 220 r / min for 18 min, 0.7 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, 0.4 parts by weight of N-hydroxysuccinimide and 1.6 parts by weight of ethylenediamine were added. The pH was adjusted to 5.7. The mixture was heated to 37 °C under a nitrogen atmosphere and stirred for 19.5 h. After the reaction was completed, the mixture was cooled to 26 °C. Five times the volume of anhydrous ethanol was added to the reaction mixture. The precipitate was collected by centrifugation at 8000 r / min for 10 min. After washing three times with deionized water, the precipitate was dried under vacuum at 60 °C for 10 h to obtain carboxy-amino functionalized cyclodextrin. Ten parts by weight of carboxyl-amino functionalized cyclodextrin were dispersed in 80 parts by weight of anhydrous methanol. After stirring at 260 r / min for 18 min, 0.35 parts by weight of D-gluconic acid lactone and 0.55 parts by weight of triethylamine were added, the pH was adjusted to 7.7, the temperature was raised to 42℃ and the reaction was stirred for 9.5 h. After the reaction was completed, the temperature was cooled to 26℃, and five times the volume of anhydrous ethanol was added. The precipitate was collected by centrifugation at 8000 r / min for 10 min, washed three times with anhydrous ethanol, and dried under vacuum at 50℃ for 12 h to obtain multi-group cyclodextrin. Ten parts by weight of polycyclic cyclodextrin were dispersed in 100 parts by weight of deionized water. After stirring at 230 r / min for 14 min, 0.8 parts by weight of calcium chloride were added to adjust the pH to 7.7. The reaction was continued at 58 °C for 70 min. After the reaction was completed, the mixture was cooled to 26 °C, and three times the volume of anhydrous ethanol was added. After standing for 3 h, the precipitate was collected by centrifugation at 6000 r / min for 10 min. The precipitate was washed three times with deionized water and then vacuum dried at 50 °C for 10 h to obtain modified cyclodextrin.

[0030] Preparation Example 5 The preparation method of modified cyclodextrin includes the following steps: 10 parts by weight of β-cyclodextrin and 3.0 parts by weight of sodium hydroxide were dispersed in 100 parts by weight of deionized water and stirred at 300 r / min for 15 min. 6.5 parts by weight of chloroacetic acid were added to adjust the pH to 11. The temperature was raised to 55 °C and the reaction was stirred for 4.5 h. After the reaction was completed, the temperature was cooled to 26 °C and the pH was adjusted to 7.0. 5 times the volume of methanol of the reaction solution was added. The precipitate was collected by centrifugation at 8000 r / min for 10 min. The precipitate was washed 3 times with deionized water and then dried under vacuum at 60 °C for 10 h to obtain carboxymethyl cyclodextrin. Ten parts by weight of carboxymethyl cyclodextrin were dispersed in 200 parts by weight of anhydrous dimethyl sulfoxide. After stirring at 250 r / min for 20 min, 0.8 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, 0.5 parts by weight of N-hydroxysuccinimide and 1.8 parts by weight of ethylenediamine were added. The pH was adjusted to 6, and the mixture was heated to 38 °C under a nitrogen atmosphere and stirred for 20 h. After the reaction was completed, the mixture was cooled to 26 °C, and five times the volume of anhydrous ethanol was added. The precipitate was collected by centrifugation at 8000 r / min for 10 min. After washing three times with deionized water, the precipitate was dried under vacuum at 60 °C for 10 h to obtain carboxy-amino functionalized cyclodextrin. Ten parts by weight of carboxyl-amino functionalized cyclodextrin were dispersed in 80 parts by weight of anhydrous methanol. After stirring at 280 r / min for 20 min, 0.4 parts by weight of D-gluconic acid lactone and 0.6 parts by weight of triethylamine were added, the pH was adjusted to 8, the temperature was raised to 45℃ and the reaction was stirred for 10 h. After the reaction was completed, the temperature was cooled to 26℃, and five times the volume of anhydrous ethanol was added. The precipitate was collected by centrifugation at 8000 r / min for 10 min, washed three times with anhydrous ethanol, and dried under vacuum at 50℃ for 12 h to obtain multi-group cyclodextrin. Ten parts by weight of polycyclic cyclodextrin were dispersed in 100 parts by weight of deionized water. After stirring at 250 r / min for 15 min, 0.9 parts by weight of calcium chloride were added to adjust the pH to 8. The reaction was continued at 60℃ for 80 min. After the reaction was completed, the mixture was cooled to 26℃, and three times the volume of anhydrous ethanol was added. After standing for 3 h, the precipitate was collected by centrifugation at 6000 r / min for 10 min. The precipitate was washed three times with deionized water and then vacuum dried at 50℃ for 10 h to obtain modified cyclodextrin.

[0031] Preparation Example 6 The preparation method of modified cellulose includes the following steps: 10 parts by weight of microcrystalline cellulose were dispersed in 100 parts by weight of anhydrous ethanol. After stirring at 300 r / min for 15 min, 4.2 parts by weight of ammonium dihydrogen phosphate and 0.8 parts by weight of urea were added. The mixture was heated to 60 °C and stirred for 2 h. After the reaction was completed, the mixture was cooled to 26 °C and centrifuged at 10000 r / min for 10 min to collect the precipitate. The precipitate was washed three times with deionized water and then dried under vacuum at 60 °C for 8 h to obtain phosphorylated cellulose. Ten parts by weight of phosphorylated cellulose were dispersed in 100 parts by weight of deionized water. After stirring at 250 r / min for 15 min, 1.6 parts by weight of sodium 2-chloroethanesulfonate and 0.8 parts by weight of sodium hydroxide were added. The mixture was heated to 85 °C under a nitrogen atmosphere and stirred for 12 h. After the reaction was completed, the mixture was cooled to 26 °C, and four times the volume of anhydrous ethanol was added. The mixture was centrifuged at 8000 r / min for 10 min to collect the precipitate. The precipitate was washed three times with deionized water and dried under vacuum at 50 °C for 12 h to obtain modified cellulose.

[0032] Preparation Example 7 The preparation method of modified cellulose includes the following steps: Ten parts by weight of microcrystalline cellulose were dispersed in 100 parts by weight of anhydrous ethanol. After stirring at 320 r / min for 16 min, 4.3 parts by weight of ammonium dihydrogen phosphate and 0.9 parts by weight of urea were added. The mixture was heated to 62 °C and stirred for 2.2 h. After the reaction was completed, the mixture was cooled to 26 °C and centrifuged at 10000 r / min for 10 min to collect the precipitate. The precipitate was washed three times with deionized water and then dried under vacuum at 60 °C for 8 h to obtain phosphorylated cellulose. Ten parts by weight of phosphorylated cellulose were dispersed in 100 parts by weight of deionized water. After stirring at 270 r / min for 16 min, 1.7 parts by weight of sodium 2-chloroethanesulfonate and 0.9 parts by weight of sodium hydroxide were added. The mixture was heated to 87 °C under a nitrogen atmosphere and stirred for 12.5 h. After the reaction was completed, the mixture was cooled to 26 °C and four times the volume of anhydrous ethanol was added. The mixture was centrifuged at 8000 r / min for 10 min to collect the precipitate. The precipitate was washed three times with deionized water and dried under vacuum at 50 °C for 12 h to obtain modified cellulose.

[0033] Preparation Example 8 The preparation method of modified cellulose includes the following steps: Ten parts by weight of microcrystalline cellulose were dispersed in 100 parts by weight of anhydrous ethanol. After stirring at 350 r / min for 18 min, 4.35 parts by weight of ammonium dihydrogen phosphate and 1.0 part by weight of urea were added. The mixture was heated to 65 °C and stirred for 2.5 h. After the reaction was completed, the mixture was cooled to 26 °C and centrifuged at 10000 r / min for 10 min to collect the precipitate. The precipitate was washed three times with deionized water and then dried under vacuum at 60 °C for 8 h to obtain phosphorylated cellulose. Ten parts by weight of phosphorylated cellulose were dispersed in 100 parts by weight of deionized water. After stirring at 300 r / min for 18 min, 1.8 parts by weight of sodium 2-chloroethanesulfonate and 1.0 parts by weight of sodium hydroxide were added. The mixture was heated to 90 °C under a nitrogen atmosphere and stirred for 13 h. After the reaction was completed, the mixture was cooled to 26 °C, and four times the volume of anhydrous ethanol was added. The mixture was centrifuged at 8000 r / min for 10 min to collect the precipitate. The precipitate was washed three times with deionized water and dried under vacuum at 50 °C for 12 h to obtain modified cellulose.

[0034] Preparation Example 9 The preparation method of modified cellulose includes the following steps: 10 parts by weight of microcrystalline cellulose were dispersed in 100 parts by weight of anhydrous ethanol. After stirring at 380 r / min for 19 min, 4.4 parts by weight of ammonium dihydrogen phosphate and 1.1 parts by weight of urea were added. The mixture was heated to 68 °C and stirred for 2.8 h. After the reaction was completed, the mixture was cooled to 26 °C and centrifuged at 10000 r / min for 10 min to collect the precipitate. The precipitate was washed three times with deionized water and then dried under vacuum at 60 °C for 8 h to obtain phosphorylated cellulose. Ten parts by weight of phosphorylated cellulose were dispersed in 100 parts by weight of deionized water. After stirring at 320 r / min for 19 min, 1.9 parts by weight of sodium 2-chloroethanesulfonate and 1.1 parts by weight of sodium hydroxide were added. The mixture was heated to 92 °C under a nitrogen atmosphere and stirred for 13.5 h. After the reaction was completed, the mixture was cooled to 26 °C and four times the volume of anhydrous ethanol was added. The mixture was centrifuged at 8000 r / min for 10 min to collect the precipitate. The precipitate was washed three times with deionized water and dried under vacuum at 50 °C for 12 h to obtain modified cellulose.

[0035] Preparation Example 10 The preparation method of modified cellulose includes the following steps: 10 parts by weight of microcrystalline cellulose were dispersed in 100 parts by weight of anhydrous ethanol. After stirring at 400 r / min for 20 min, 4.5 parts by weight of ammonium dihydrogen phosphate and 1.2 parts by weight of urea were added. The mixture was heated to 70 °C and stirred for 3 h. After the reaction was completed, the mixture was cooled to 26 °C and centrifuged at 10000 r / min for 10 min to collect the precipitate. The precipitate was washed three times with deionized water and then dried under vacuum at 60 °C for 8 h to obtain phosphorylated cellulose. Ten parts by weight of phosphorylated cellulose were dispersed in 100 parts by weight of deionized water. After stirring at 350 r / min for 20 min, 2.0 parts by weight of sodium 2-chloroethanesulfonate and 1.2 parts by weight of sodium hydroxide were added. The mixture was heated to 95 °C under a nitrogen atmosphere and stirred for 14 h. After the reaction was completed, the mixture was cooled to 26 °C and four times the volume of anhydrous ethanol was added. The mixture was centrifuged at 8000 r / min for 10 min to collect the precipitate. The precipitate was washed three times with deionized water and dried under vacuum at 50 °C for 12 h to obtain modified cellulose.

[0036] Preparation Example 11 The preparation method of modified cyclodextrin includes the following steps: Remove calcium chloride from Preparation Example 5, and keep all other operations the same as in Preparation Example 5. Example

[0037] A method for extracting sodium glycolate from pesticide wastewater includes the following steps: 2,4-D production wastewater (pH≈8) was adjusted to pH 3.0 with 36wt% hydrochloric acid solution. After stirring at 200 r / min for 10 min, the filtrate was collected by filtration through a 0.22 μm filter membrane. The pH of the filtrate was adjusted to 8.0 with sodium hydroxide solid. The solution was concentrated under reduced pressure at 60℃. During the concentration process, the precipitated sodium chloride solid was filtered intermittently until the sodium glycolate content in the solution reached 40% to obtain the concentrated solution. The above concentrated solution, the modified cyclodextrin of Preparation Example 1, and the modified cellulose of Preparation Example 6 were mixed at a weight ratio of 100:0.8:0.1. The mixture was heated to 90°C and stirred at 200 r / min for 20 min. The mixture was then cooled to 40°C at a rate of 1°C / min and kept at this temperature for 40 min to grow crystals. The mixture was then stirred at 150 r / min and cooled to 15°C at a rate of 1°C / min. After keeping at this temperature for 2 h to grow crystals, the filter cake was collected by vacuum filtration. The above filter cake was placed in 0.5 times its weight of deionized water at 4℃ and allowed to stand for 10 minutes. Then, it was stirred and dispersed at 100 r / min for 30 minutes. After that, it was filtered under reduced pressure. The filtrate was an aqueous solution of sodium glycolate, and the filter residue consisted of two modified materials. The filtrate was then vacuum dried at 105℃ for 6 hours to obtain sodium glycolate. Example

[0038] A method for extracting sodium glycolate from pesticide wastewater includes the following steps: 2,4-D production wastewater (pH≈8) was adjusted to pH 3.0 with 36wt% hydrochloric acid solution. After stirring at 200 r / min for 10 min, the filtrate was collected by filtration through a 0.22 μm filter membrane. The pH of the filtrate was adjusted to 8.0 with sodium hydroxide solid. The solution was concentrated under reduced pressure at 60℃. During the concentration process, the precipitated sodium chloride solid was filtered intermittently until the sodium glycolate content in the solution reached 40% to obtain the concentrated solution. The above concentrated solution, the modified cyclodextrin of Preparation Example 2, and the modified cellulose of Preparation Example 7 were mixed at a weight ratio of 100:0.9:0.15. The mixture was heated to 92°C and stirred at 200 r / min for 22 min. The mixture was then cooled to 42°C at a rate of 1°C / min and kept at a constant temperature for 45 min. The mixture was then stirred at 150 r / min and cooled to 16°C at a rate of 1°C / min. After keeping at a constant temperature for 2.2 h, the filter cake was collected by vacuum filtration. The filter cake was placed in 0.5 times its weight of deionized water at 4°C and allowed to stand for 10 minutes. Then, it was stirred and dispersed at 100 r / min for 35 minutes. After that, it was filtered under reduced pressure. The filtrate was an aqueous solution of sodium glycolate, and the filter residue consisted of two modified materials. The filtrate was then vacuum dried at 105°C for 6 hours to obtain sodium glycolate. Example

[0039] A method for extracting sodium glycolate from pesticide wastewater includes the following steps: 2,4-D production wastewater (pH≈8) was adjusted to pH 3.0 with 36wt% hydrochloric acid solution. After stirring at 200 r / min for 10 min, the filtrate was collected by filtration through a 0.22 μm filter membrane. The pH of the filtrate was adjusted to 8.0 with sodium hydroxide solid. The solution was concentrated under reduced pressure at 60℃. During the concentration process, the precipitated sodium chloride solid was filtered intermittently until the sodium glycolate content in the solution reached 40% to obtain the concentrated solution. The above concentrated solution, the modified cyclodextrin of Preparation Example 3, and the modified cellulose of Preparation Example 8 were mixed at a weight ratio of 100:1.0:0.2. The mixture was heated to 93°C and stirred at 200 r / min for 25 min. The mixture was then cooled to 45°C at a rate of 1°C / min and kept at a constant temperature for 50 min. The mixture was then stirred at 150 r / min and cooled to 16°C at a rate of 1°C / min. After keeping at a constant temperature for 2.5 h, the filter cake was collected by vacuum filtration. The above filter cake was placed in 0.5 times its weight of deionized water at 4℃ and allowed to stand for 10 minutes. Then, it was stirred and dispersed at 100 r / min for 40 minutes. After that, it was filtered under reduced pressure. The filtrate was an aqueous solution of sodium glycolate, and the filter residue consisted of two modified materials. The filtrate was then vacuum dried at 105℃ for 6 hours to obtain sodium glycolate. Example

[0040] A method for extracting sodium glycolate from pesticide wastewater includes the following steps: 2,4-D production wastewater (pH≈8) was adjusted to pH 3.0 with 36wt% hydrochloric acid solution. After stirring at 200 r / min for 10 min, the filtrate was collected by filtration through a 0.22 μm filter membrane. The pH of the filtrate was adjusted to 8.0 with sodium hydroxide solid. The solution was concentrated under reduced pressure at 60℃. During the concentration process, the precipitated sodium chloride solid was filtered intermittently until the sodium glycolate content in the solution reached 40% to obtain the concentrated solution. The above concentrated solution, the modified cyclodextrin of Preparation Example 4, and the modified cellulose of Preparation Example 9 were mixed at a weight ratio of 100:1.1:0.25. The mixture was heated to 95°C and stirred at 200 r / min for 28 min. The mixture was then cooled to 48°C at a rate of 1°C / min and kept at a constant temperature for 55 min. The mixture was then stirred at 150 r / min and cooled to 17°C at a rate of 1°C / min. After keeping at a constant temperature for 2.8 h, the filter cake was collected by vacuum filtration. The above filter cake was placed in 0.5 times its weight of deionized water at 4℃ and allowed to stand for 10 minutes. Then, it was stirred and dispersed at 100 r / min for 45 minutes. After that, it was filtered under reduced pressure. The filtrate was an aqueous solution of sodium glycolate, and the filter residue consisted of two modified materials. The filtrate was then vacuum dried at 105℃ for 6 hours to obtain sodium glycolate. Example

[0041] A method for extracting sodium glycolate from pesticide wastewater includes the following steps: 2,4-D production wastewater (pH≈8) was adjusted to pH 3.0 with 36wt% hydrochloric acid solution. After stirring at 200 r / min for 10 min, the filtrate was collected by filtration through a 0.22 μm filter membrane. The pH of the filtrate was adjusted to 8.0 with sodium hydroxide solid. The solution was concentrated under reduced pressure at 60℃. During the concentration process, the precipitated sodium chloride solid was filtered intermittently until the sodium glycolate content in the solution reached 40% to obtain the concentrated solution. The above concentrated solution, the modified cyclodextrin of Preparation Example 5, and the modified cellulose of Preparation Example 10 were mixed at a weight ratio of 100:1.2:0.3. The mixture was heated to 96°C and stirred at 200 r / min for 30 min. The mixture was then cooled to 50°C at a rate of 1°C / min and kept at a constant temperature for 60 min. The mixture was then stirred at 150 r / min and cooled to 18°C ​​at a rate of 1°C / min. After keeping at a constant temperature for 3 h, the filter cake was collected by vacuum filtration. The above filter cake was placed in 0.5 times its weight of deionized water at 4℃ and allowed to stand for 10 minutes. Then, it was stirred and dispersed at 100 r / min for 50 minutes. After that, it was filtered under reduced pressure. The filtrate was an aqueous solution of sodium glycolate, and the filter residue consisted of two modified materials. The filtrate was then vacuum dried at 105℃ for 6 hours to obtain sodium glycolate.

[0042] Comparative Example 1 A method for extracting sodium glycolate from pesticide wastewater includes the following steps: The modified cyclodextrin prepared in Example 5 was replaced with unmodified β-cyclodextrin, and all other operations were the same as in Example 5.

[0043] Comparative Example 2 A method for extracting sodium glycolate from pesticide wastewater includes the following steps: The modified cellulose in Example 10 of Example 5 was replaced with unmodified microcrystalline cellulose, and all other operations were the same as in Example 5.

[0044] Comparative Example 3 A method for extracting sodium glycolate from pesticide wastewater includes the following steps: The modified cyclodextrin prepared in Example 5 was replaced with carboxymethyl cyclodextrin, and all other operations were the same as in Example 5.

[0045] Comparative Example 4 A method for extracting sodium glycolate from pesticide wastewater includes the following steps: The modified cellulose in Example 10 of Example 5 was replaced with phosphorylated cellulose only, and all other operations were the same as in Example 5.

[0046] Comparative Example 5 A method for extracting sodium glycolate from pesticide wastewater includes the following steps: The modified cellulose from Preparation Example 10 in Example 5 was removed, and all other operations remained the same as in Example 5.

[0047] Comparative Example 6 A method for extracting sodium glycolate from pesticide wastewater includes the following steps: The modified cyclodextrin of Example 5 was removed from the preparation of Example 5, and all other operations were the same as in Example 5.

[0048] Comparative Example 7 A method for extracting sodium glycolate from pesticide wastewater includes the following steps: The modified cyclodextrin of Preparation Example 5 in Example 5 was replaced with the modified cyclodextrin of Preparation Example 11, and all other operations were the same as in Example 5.

[0049] Comparative Example 8 A method for extracting sodium glycolate from pesticide wastewater includes the following steps: Wastewater pretreatment does not involve filtration to remove impurities or intermittent filtration of sodium chloride; other operations remain consistent with Example 5.

[0050] Comparative Example 9 A method for extracting sodium glycolate from pesticide wastewater includes the following steps: The modified cyclodextrin of Preparation Example 5 and the modified cellulose of Preparation Example 10 in Example 5 were removed. Conventional cooling crystallization was used, and other operations were consistent with those in Example 5.

[0051] Performance testing The sodium glycolate extracted in Examples 1-5 and Comparative Examples 1-9 were subjected to various performance tests, and the test methods are as follows: Sodium glycolate purity: A reversed-phase column was used with a phosphate buffer aqueous solution as the mobile phase. The detection wavelength was set to 210 nm, the column temperature to 30 ℃, the mobile phase flow rate to 1.0 mL / min, and the injection volume to 20 μL. The sample solution was injected into the high-performance liquid chromatograph, and the peak area was recorded. The actual content of sodium glycolate in the sample was calculated by combining the standard curve. Sodium glycolate purity = (actual mass of sodium glycolate in the sample / total mass of the sample) × 100%; Sodium glycolate yield: The yield was calculated based on the theoretical total mass of sodium glycolate in the pretreated concentrate and the final mass of dried sodium glycolate product. The test results are shown in Table 1.

[0052] Table 1. Performance Test Results

[0053] Examples 1-5 all employed a modified cyclodextrin and modified cellulose composite system for sodium glycolate extraction experiments. The cyclodextrin, after multi-step continuous modification, is enriched with various functional groups on its surface, enabling it to specifically recognize sodium glycolate through intermolecular interactions and effectively inhibiting the co-crystallization of sodium chloride and sodium glycolate. The modified cellulose, after phosphorylation and sulfonation grafting modification, can both anchor the modified cyclodextrin through coordination and maintain the system's dispersion in high-salt environments, preventing the aggregation and sedimentation of functional materials. The two materials form a synergistic system with complementary functions, making the entire crystallization process stable and controllable, effectively reducing the sodium chloride impurity content in the product, ensuring the purification effect of sodium glycolate, and making it suitable for the resource recovery treatment of 2,4-D pesticide wastewater.

[0054] The reason for the decrease in Comparative Example 1 may be that the unmodified β-cyclodextrin did not introduce various functional groups and did not have the ability to specifically recognize sodium glycolate and block co-crystallization. At the same time, native cyclodextrin is prone to agglomeration in high-salt systems and cannot play a regulatory role in the crystallization process.

[0055] The reason for the decrease in Comparative Example 2 may be that the unmodified microcrystalline cellulose only contains the basic hydroxyl structure and lacks phosphate groups and sodium sulfonate groups. It cannot anchor the modified cyclodextrin to alleviate the agglomeration problem, nor does it have the ability to disperse in a high-salt environment. The uniformity of the system is destroyed, and impurities are easily carried in during the crystallization process.

[0056] The reason for the decrease in Comparative Example 3 may be that only the intermediate product carboxymethyl cyclodextrin was used, omitting key modification processes such as amino grafting, polyhydroxy modification, and calcium ion coordination. As a result, the material surface lacks sufficient functional groups and activation sites, and its ability to recognize sodium glycolate and inhibit co-crystallization is significantly weakened.

[0057] The reason for the decrease in Comparative Example 4 may be that only phosphorylated cellulose was used without subsequent sodium sulfonate grafting modification. The material lacks key functional groups for high salt resistance, making it difficult to maintain stable dispersion in high salt concentrate. Modified cyclodextrin is prone to sedimentation, interfering with the normal crystallization process.

[0058] The reason for the decrease in Comparative Example 5 may be that no modified cellulose was added to the system. Modified cyclodextrin used alone will quickly agglomerate in a high-salt environment and cannot be evenly distributed in the solution to play its role. Local crystallization areas are prone to being mixed with sodium chloride impurities.

[0059] The reason for the decrease in Comparative Example 6 may be that the core functional material modified cyclodextrin was removed from the system. Modified cellulose alone cannot achieve specific recognition of sodium glycolate, nor can it block the co-crystallization behavior of sodium chloride. The crystallization process lacks directional regulation.

[0060] The reason for the decrease in Comparative Example 7 may be that calcium chloride coordination modification was not carried out during the preparation stage of the modified cyclodextrin. The material lacks metal coordination binding sites, which weakens the recognition, adsorption and crystallization induction effect of sodium glycolate, and the ability to inhibit co-crystallization decreases accordingly.

[0061] The reason for the decrease in Comparative Example 8 may be that the wastewater was not fully pretreated, and residual solid impurities and unfiltered sodium chloride in the system will participate in the crystallization process and be directly mixed inside the sodium glycolate crystals, resulting in a decrease in product purity.

[0062] The reason for the decrease in Comparative Example 9 may be that no modified functional materials were added to the system, and the traditional cooling crystallization method was used. This method could not avoid the inherent problem of co-crystallization of sodium chloride and sodium glycolate. The crystallization process lacked selectivity, resulting in poor final purification effect.

[0063] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for extracting sodium glycolate from a pesticide wastewater, characterized by, The method includes the following steps: After adjusting the pH of the 2,4-D production wastewater to 3.0 and stirring, the filtrate was collected by filtration. The pH of the filtrate was then adjusted to 8.0 and concentrated under reduced pressure to obtain a concentrated solution. The concentrate, modified cyclodextrin and modified cellulose are mixed at a weight ratio of 100:0.8~1.2:0.1~0.

3. After the first mixing and stirring, the mixture is cooled and then mixed and stirred a second time. After cooling again and then mixing and stirring a third time, the filter cake is collected. After mixing and stirring the filter cake and deionized water, the filtrate was collected by filtration and then dried under vacuum to obtain sodium glycolate. The preparation method of the modified cyclodextrin includes the following steps: β-Cyclodextrin, sodium hydroxide, and chloroacetic acid were mixed and stirred in a weight ratio of 10:2.5~3.0:5.5~6.5 to obtain carboxymethyl cyclodextrin. Carboxymethyl cyclodextrin, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide and ethylenediamine were mixed and stirred in a weight ratio of 10:0.5~0.8:0.2~0.5:1.2~1.8 to obtain carboxy-amino functionalized cyclodextrin. Carboxy-amino functionalized cyclodextrin, D-glucanolactone, and triethylamine were mixed and stirred in a weight ratio of 10:0.2~0.4:0.4~0.6 to obtain multi-functionalized cyclodextrin. Modified cyclodextrin was obtained by mixing and stirring poly-functional cyclodextrin and calcium chloride at a weight ratio of 10:0.5~0.

9.

2. The process for extracting sodium glycolate from agrochemical wastewater as claimed in claim 1 wherein, The conditions for adjusting the pH to 3.0 and stirring include a stirring speed of 200 r / min and a stirring time of 10 min; the sodium glycolate content in the concentrate is 40%.

3. The process as claimed in claim 1, wherein the process for the extraction of sodium glycolate from the agrochemical wastewater is characterized by, The reaction conditions for the mixture of β-cyclodextrin, sodium hydroxide, and chloroacetic acid include a reaction pH of 10-11, a reaction temperature of 45-55℃, and a reaction time of 3.5-4.5 h; the reaction conditions for the mixture of carboxymethyl cyclodextrin, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, and ethylenediamine include a reaction pH of 5-6, a reaction temperature of 34-38℃, and a reaction time of 18-20 h.

4. The process as claimed in claim 1, wherein the process for the extraction of sodium glycolate from the agrochemical wastewater is characterized by, The conditions for the mixed stirring reaction of the carboxyl-amino functionalized cyclodextrin, D-gluconic acid lactone and triethylamine include a reaction pH of 7-8, a reaction temperature of 34-45℃ and a reaction time of 8-10h; the conditions for the mixed stirring reaction of the multi-functionalized cyclodextrin and calcium chloride include a reaction pH of 7-8, a reaction temperature of 50-60℃ and a reaction time of 50-80min.

5. The method for extracting sodium glycolate from pesticide wastewater as described in claim 1, characterized in that, The method for preparing the modified cellulose includes the following steps: Microcrystalline cellulose, ammonium dihydrogen phosphate, and urea were mixed and stirred in a weight ratio of 10:4.2~4.5:0.8~1.2 to obtain phosphorylated cellulose. Modified cellulose was obtained by mixing and stirring phosphorylated cellulose, sodium 2-chloroethane sulfonate and sodium hydroxide in a weight ratio of 10:1.6~2.0:0.8~1.

2.

6. The method for extracting sodium glycolate from pesticide wastewater as described in claim 5, characterized in that, The conditions for the mixed stirring reaction of microcrystalline cellulose, ammonium dihydrogen phosphate and urea include a reaction temperature of 60-70℃ and a reaction time of 2-3h; the conditions for the mixed stirring reaction of phosphorylated cellulose, sodium 2-chloroethane sulfonate and sodium hydroxide include a reaction temperature of 85-95℃ and a reaction time of 12-14h.

7. The method for extracting sodium glycolate from pesticide wastewater as described in claim 1, characterized in that, The conditions for the first mixing and stirring include a stirring temperature of 90~96℃, a stirring speed of 200r / min, and a stirring time of 20~30min.

8. The method for extracting sodium glycolate from pesticide wastewater as described in claim 1, characterized in that, The conditions for the second mixing and stirring include a stirring temperature of 40~50℃, a stirring speed of 200r / min, and a stirring time of 40~60min.

9. The method for extracting sodium glycolate from pesticide wastewater as described in claim 1, characterized in that, The conditions for the third mixing and stirring include a stirring temperature of 15~18℃, a stirring speed of 150r / min, and a stirring time of 2~3h.

10. The method for extracting sodium glycolate from pesticide wastewater as described in claim 1, characterized in that, The weight ratio of the filter cake to deionized water is 1:0.5; the mixing conditions for the filter cake and deionized water include a stirring speed of 100 r / min and a stirring time of 30~50 min.

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