Efficient and environment-friendly butyl acrylate high-salinity wastewater treatment process

Abstract

The invention relates to the technical field of wastewater treatment, in particular to an efficient and environment-friendly butyl acrylate high-salinity wastewater treatment process which comprises the following steps: S1, acidification replacement, S2, extraction separation, S3, rectification and recovery, S4, refining and purification, S5, neutralization and adjustment, and S6, evaporative crystallization. According to the method, efficient and rapid separation of the oil phase and the water phase is realized by adopting a separation scheme of combining the centrifugal extractor and the molecular sieve membrane, meanwhile, the moisture content in the organic phase is effectively controlled, and the organic phase is deeply refined by adopting the continuous ion exchange equipment and the macroporous strong-acid cation exchange resin, so that the separation efficiency is improved. Trace sodium ions and other impurities can be specifically adsorbed and removed, so that the purity of the recycled acrylic acid product is improved in a breakthrough manner, and the recycling requirement of a high-end production device is met.

Description

A highly efficient and environmentally friendly process for treating high-salt butyl acrylate wastewater Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a highly efficient and environmentally friendly process for treating high-salt butyl acrylate wastewater. Background Technology

[0002] High-salt butyl acrylate wastewater is a complex type of industrial wastewater generated during the production of butyl acrylate. It mainly contains unreacted sodium acrylate, n-butanol, by-product salts, and trace additives. This type of wastewater is characterized by high chemical oxygen demand, high salt concentration, and poor biodegradability. It is a key challenge in achieving clean and resource-efficient production of butyl acrylate. How to achieve efficient recovery and harmless treatment of high-value components in this type of wastewater is an important research direction in the field of chemical wastewater resource utilization.

[0003] Traditional extraction-distillation processes for treating high-salt butyl acrylate wastewater have limited separation precision, making it difficult to effectively address the issue of trace inorganic ions remaining in the organic phase during extraction. This directly affects the purity and value of the recovered organic matter, resulting in low-value resource products. Therefore, this invention provides a highly efficient and environmentally friendly process for treating high-salt butyl acrylate wastewater. Summary of the Invention

[0004] The purpose of this invention is to provide a highly efficient and environmentally friendly process for treating high-salt butyl acrylate wastewater, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a highly efficient and environmentally friendly process for treating high-salt butyl acrylate wastewater, comprising the following steps: S1: acidification and replacement, the high-salt butyl acrylate wastewater is fed into a strong acid replacement vessel, concentrated sulfuric acid is added to adjust the pH, the reaction is maintained at a constant temperature, and after the reaction is completed, the wastewater is cooled to 35°C via a heat exchanger to obtain pretreated wastewater; S2: extraction and separation, the pretreated wastewater is fed into a centrifugal extractor, and after centrifugal extraction, an oil phase and an aqueous phase are obtained. The oil phase is fed into a molecular sieve membrane to obtain an organic phase, and the aqueous phase is reserved for use; S3: distillation and recovery, the aqueous phase is fed into a distillation column for azeotropic distillation; S4: purification, the organic phase is purified and reused in the production unit; S5: neutralization and adjustment, the wastewater from the bottom of the distillation column generated in S3 is neutralized and adjusted to obtain a treated liquid; S6: evaporation and crystallization, the treated liquid is fed into an MVR evaporation system, and sodium sulfate solid is separated by preheating and evaporation crystallization.

[0006] Preferably, the pH value in S1 is adjusted to 1.5-2.0 by concentrated sulfuric acid, and the reaction temperature is 60℃.

[0007] Preferably, in S2, the pretreated wastewater is dehydrated to below 1000 ppm after passing through a centrifugal extractor.

[0008] Preferably, the distillation recovery method is as follows: the aqueous phase is preheated to 65-70°C and then enters the distillation column. The working temperature is 110-120°C. An azeotrope of n-butanol and water is generated at the top of the column. After being condensed to 35°C by circulating water, condensation and separation occur. After condensation and separation, the butanol is reused, and the remaining material is partially recycled into the MVR evaporation system of S6.

[0009] Preferably, the distillation column in S3 operates at a temperature of 110–120°C and a pressure of -0.1 MPaG, and the wastewater in the column bottom contains 10–15% sodium sulfate.

[0010] Preferably, the method for refining and purifying the organic phase is as follows: the organic phase is pumped into a continuous ion exchange device, and the organic phase is adsorbed using a resin adsorption column. The organic phase flows out from the bottom of the column to complete the refining and purification process, and the resulting product is recycled to the production equipment.

[0011] Preferably, the resin adsorption column in S4 is a macroporous strong acid cation exchange resin, the adsorption flow rate is 2-5 BV / h, and the adsorption treatment temperature is 25-35℃.

[0012] Preferably, the neutralization and adjustment method is as follows: the distillation column bottom wastewater generated in S3 is mixed and neutralized with sodium hydroxide solution in a static mixer, the pH value is adjusted to 6.5-7.5, the neutralized wastewater is passed into an oxidation reactor and treated under ultraviolet photocatalysis for 2-4 hours to obtain a treated solution.

[0013] Preferably, the mass concentration of the sodium hydroxide solution in S5 is 4-5%.

[0014] Preferably, the evaporation crystallization method is as follows: the processing liquid is introduced into the MVR evaporation system, preheated to 85-90°C, and then the liquid enters the forced circulation evaporation crystallizer. The compressor inlet temperature is 90-95°C, the temperature rise is 15°C, and the steam flow rate is 1.2-1.5 t / h. The resulting product is thickened by a thickener and dehydrated by a centrifuge to obtain a wet material. The wet material then enters the fluidized bed drying and cooling system, and after drying, sodium sulfate solid is obtained. The sodium sulfate is dried, packaged, and sold.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In the present invention, the separation scheme combining centrifugal extractor and molecular sieve membrane is adopted to achieve efficient and rapid separation of oil and water phases, while effectively controlling the water content in the organic phase. Furthermore, by using a continuous ion exchange device and macroporous strong acid cation exchange resin to deeply purify the organic phase, trace amounts of impurities such as sodium ions can be specifically adsorbed and removed, resulting in a breakthrough improvement in the purity of the recovered acrylic acid product, meeting the reuse requirements of high-end production equipment. At the same time, the introduction of ultraviolet photocatalytic oxidation treatment after the neutralization and adjustment step can effectively degrade the recalcitrant organic matter remaining in the bottom wastewater of the distillation column. This lays a solid foundation for the subsequent MVR evaporation and crystallization to prepare high-purity, high-quality sodium sulfate products, solving the problem of poor quality of by-product salt from the source.

[0016] 2. In this invention, the use of a centrifugal extractor enhances mass transfer efficiency and shortens separation time. The application of molecular sieve membranes further ensures the dryness of the organic phase. The distillation unit operates under optimized temperature and pressure parameters, resulting in reasonable energy consumption. In particular, the core MVR evaporation crystallization system significantly reduces the consumption of fresh steam by efficiently recovering and utilizing the energy of secondary steam through a compressor. The entire system, through precise control, ensures continuous, stable, and long-term operation under harsh process conditions, demonstrating both excellent reliability and economy.

[0017] 3. In this invention, not only are acrylic acid and n-butanol efficiently recovered and directly reused in the main production line, forming a closed-loop cycle within the plant, but also sodium sulfate in wastewater is converted into qualified industrial products through mature MVR evaporation and crystallization technology, realizing the comprehensive resource utilization of waste. Furthermore, the condensate discharged at the end of the treatment process can be reused, reducing pollution generation and achieving both economic and environmental benefits. Attached Figure Description

[0018] Figure 1 is a flowchart of a highly efficient and environmentally friendly butyl acrylate high-salt wastewater treatment process proposed in this invention. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that the raw materials used in the following embodiments are all commercially available.

[0021] Example 1: A highly efficient and environmentally friendly process for treating high-salt butyl acrylate wastewater includes the following steps: S1: Acidification and replacement, the high-salt butyl acrylate wastewater is passed into a strong acid replacement vessel, concentrated sulfuric acid is added to adjust the pH, the reaction is kept at a constant temperature, and after the reaction is completed, the wastewater is cooled to 35°C through a heat exchanger to obtain pretreated wastewater, wherein the concentrated sulfuric acid adjusts the pH value to 1.5, and the reaction temperature is 60°C.

[0022] S2: Extraction and separation. Pretreated wastewater is fed into a centrifugal extractor. After centrifugal extraction, an oil phase and an aqueous phase are obtained. The oil phase is passed through a molecular sieve membrane to obtain an organic phase, while the aqueous phase is reserved for later use. The pretreated wastewater is dehydrated to below 1000 ppm after centrifugal extraction. S3: Distillation and recovery. The aqueous phase is fed into a distillation column for azeotropic distillation. The distillation recovery method is as follows: the aqueous phase is preheated to 65°C before entering the distillation column, which operates at 110°C. An azeotrope of n-butanol and water is generated at the top of the column. After condensation to 35°C via circulating water, condensation and stratification occur. The butanol is reused, and the remaining material is partially recycled back to the MVR evaporation system in S6. The distillation column operates at 110°C and -0.1 MPaG. The bottom wastewater contains 10% sodium sulfate. S4: Refining and purification. The organic phase is refined and reused in the production unit. The method for refining and purifying the organic phase is as follows. The process is as follows: 1) The organic phase is pumped into a continuous ion exchange device, where it is adsorbed using a resin adsorption column. The organic phase flows out from the bottom of the column, completing the purification process. The resulting product is recycled back into the production unit. The resin adsorption column uses a macroporous, strongly acidic cation exchange resin, with an adsorption flow rate of 2 BV / h and an adsorption temperature of 25℃. 2) Neutralization and adjustment: The distillation column bottom wastewater generated in step S3 is neutralized and adjusted to obtain a treated liquid. The neutralization and adjustment method involves mixing the distillation column bottom wastewater generated in step S3 with a sodium hydroxide solution in a static mixer to adjust the pH to 6.5. The neutralized wastewater is then passed into an oxidation reactor and treated under ultraviolet light catalysis for 2 hours to obtain a treated liquid. The sodium hydroxide solution has a mass concentration of 4%. 3) Evaporation and crystallization: The treated liquid is passed into an MVR evaporation system, where it is preheated and then evaporated and crystallized to separate solid sodium sulfate.

[0023] The evaporation crystallization method is as follows: the treatment liquid is introduced into the MVR evaporation system, preheated to 85°C, and then the liquid enters the forced circulation evaporation crystallizer. The compressor inlet temperature is 90°C, the temperature rise is 15°C, and the steam flow rate is 1.2t / h. The resulting product is thickened by a thickener and dehydrated by a centrifuge to obtain a wet material. The wet material then enters the fluidized bed drying and cooling system. After drying, sodium sulfate solid is obtained. The sodium sulfate is dried, packaged, and sold.

[0024] Example 2: A highly efficient and environmentally friendly process for treating high-salt butyl acrylate wastewater includes the following steps: S1: Acidification and replacement, the high-salt butyl acrylate wastewater is passed into a strong acid replacement reactor, concentrated sulfuric acid is added to adjust the pH, the reaction is kept at a constant temperature, and after the reaction is completed, the temperature is lowered to 35°C through a heat exchanger to obtain pretreated wastewater, wherein the concentrated sulfuric acid adjusts the pH value to 1.8, and the reaction temperature is 60°C.

[0025] S2: Extraction and separation. Pretreated wastewater is fed into a centrifugal extractor. After centrifugal extraction, an oil phase and an aqueous phase are obtained. The oil phase is passed through a molecular sieve membrane to obtain an organic phase, while the aqueous phase is reserved for later use. The pretreated wastewater is dehydrated to below 1000 ppm after centrifugal extraction. S3: Distillation and recovery. The aqueous phase is fed into a distillation column for azeotropic distillation. The distillation recovery method is as follows: the aqueous phase is preheated to 68°C before entering the distillation column, which operates at 115°C. An azeotrope of n-butanol and water is generated at the top of the column. After condensation to 35°C via circulating water, condensation and stratification occur. The butanol is reused, and the remaining material is partially recycled back to the MVR evaporation system in S6. The distillation column operates at 115°C and -0.1 MPaG. The bottom wastewater contains 13% sodium sulfate. S4: Refining and purification. The organic phase is refined and reused in the production unit. The method for refining and purifying the organic phase is as follows. The process is as follows: S3: The organic phase is pumped into a continuous ion exchange device, where it is adsorbed using a resin adsorption column. The organic phase flows out from the bottom of the column, completing the purification process. The resulting product is recycled back to the production unit. The resin adsorption column uses a macroporous, strongly acidic cation exchange resin, with an adsorption flow rate of 3 BV / h and an adsorption temperature of 30℃. S5: Neutralization and adjustment. The distillation column bottom wastewater generated in S3 is neutralized and adjusted to obtain a treated liquid. The neutralization and adjustment method is as follows: the distillation column bottom wastewater generated in S3 is mixed with sodium hydroxide solution in a static mixer to neutralize and adjust the pH value to 7. The neutralized wastewater is then passed into an oxidation reactor and treated under ultraviolet light catalysis for 3 hours to obtain a treated liquid. The sodium hydroxide solution has a mass concentration of 4.5%. S6: Evaporation and crystallization. The treated liquid is passed into an MVR evaporation system, where it is preheated and then evaporated and crystallized to separate solid sodium sulfate.

[0026] The evaporation crystallization method is as follows: the treatment liquid is introduced into the MVR evaporation system, preheated to 88°C, and then the liquid enters the forced circulation evaporation crystallizer. The compressor inlet temperature is 93°C, the temperature rise is 15°C, and the steam flow rate is 1.3t / h. The resulting product is thickened by a thickener and dehydrated by a centrifuge to obtain a wet material. The wet material then enters the fluidized bed drying and cooling system. After drying, sodium sulfate solid is obtained. The sodium sulfate is dried, packaged, and sold.

[0027] Example 3: A highly efficient and environmentally friendly process for treating high-salt butyl acrylate wastewater includes the following steps: S1: Acidification and replacement, the high-salt butyl acrylate wastewater is passed into a strong acid replacement reactor, concentrated sulfuric acid is added to adjust the pH, the reaction is kept at a constant temperature, and after the reaction is completed, the temperature is lowered to 35°C through a heat exchanger to obtain pretreated wastewater, wherein the pH value is adjusted to 2.0 by concentrated sulfuric acid, and the reaction temperature is 60°C.

[0028] S2: Extraction and separation. Pretreated wastewater is fed into a centrifugal extractor. After centrifugal extraction, an oil phase and an aqueous phase are obtained. The oil phase is passed through a molecular sieve membrane to obtain an organic phase, while the aqueous phase is reserved for later use. The pretreated wastewater is dehydrated to below 1000 ppm after centrifugal extraction. S3: Distillation and recovery. The aqueous phase is fed into a distillation column for azeotropic distillation. The distillation recovery method is as follows: the aqueous phase is preheated to 70°C before entering the distillation column, which operates at 120°C. An azeotrope of n-butanol and water is generated at the top of the column. After condensation to 35°C via circulating water, condensation and stratification occur. The butanol is reused, and the remaining material is partially recycled back to the MVR evaporation system in S6. The distillation column operates at 120°C and -0.1 MPaG. The bottom wastewater contains 15% sodium sulfate. S4: Refining and purification. The organic phase is refined and reused in the production unit. The method for refining and purifying the organic phase is as follows. The process is as follows: 1) The organic phase is pumped into a continuous ion exchange device, where it is adsorbed using a resin adsorption column. The organic phase flows out from the bottom of the column, completing the purification process. The resulting product is recycled back into the production unit. The resin adsorption column uses a macroporous, strongly acidic cation exchange resin, with an adsorption flow rate of 5 BV / h and an adsorption temperature of 35℃. 2) Neutralization and Adjustment: The distillation column bottom wastewater generated in S3 is neutralized and adjusted to obtain a treated liquid. The neutralization and adjustment method involves mixing the distillation column bottom wastewater generated in S3 with a sodium hydroxide solution in a static mixer to adjust the pH to 7.5. The neutralized wastewater is then passed into an oxidation reactor and treated under ultraviolet light catalysis for 4 hours to obtain a treated liquid. The sodium hydroxide solution has a mass concentration of 5%. 3) Evaporation and Crystallization: The treated liquid is passed into an MVR evaporation system, where it is preheated and then evaporated and crystallized to separate solid sodium sulfate.

[0029] The evaporation crystallization method is as follows: the treatment liquid is introduced into the MVR evaporation system, preheated to 90°C, and then the liquid enters the forced circulation evaporation crystallizer. The compressor inlet temperature is 95°C, the temperature rise is 15°C, and the steam flow rate is 1.5t / h. The resulting product is thickened by a thickener and dehydrated by a centrifuge to obtain a wet material. The wet material then enters the fluidized bed drying and cooling system. After drying, sodium sulfate solid is obtained. The sodium sulfate is dried, packaged, and sold.

[0030] Comparative Example 1 differs from Example 1 in that: this comparative example lacks molecular sieve membrane deep dehydration, that is, in step S2, after the pretreated wastewater is separated into an oil phase by a centrifugal extractor, it does not undergo molecular sieve membrane treatment and directly enters the subsequent S4 refining and purification step as the "organic phase".

[0031] Comparative Example 2 differs from Example 1 in that: in step S4 of this comparative example, a continuous ion exchange device is not used for purification, that is, the organic phase obtained in step S2 is directly recycled as the final product into the production unit.

[0032] Comparative Example 3 differs from Example 1 in that: this comparative example lacks ultraviolet photocatalytic oxidation, that is, in step S5, the neutralized wastewater is not subjected to ultraviolet photocatalytic oxidation treatment, and the neutralized liquid is directly used as the "treatment liquid" to enter the S6 evaporation and crystallization step.

[0033] Performance testing: The high-salt waste treatment processes for butyl acrylate prepared in Examples 1-3 and Comparative Examples 1-3 were tested; Organic phase moisture content: The moisture content (ppm) was tested according to GB / T6283-2008 standard and recorded in Table 1. The lower the value, the better the dehydration effect, which is beneficial to subsequent processes and product purity; Purity of recovered acrylic acid: The purity (%) of recovered acrylic acid was tested according to GB / T17529.1-2008 standard and recorded in Table 1; Purity of recovered n-butanol: The purity (%) of recovered n-butanol was tested according to GB / T6027-2023 standard and recorded in Table 1; Purity of by-product sodium sulfate: The purity (%) of sodium sulfate was tested according to GB / T6009-2014 standard and recorded in Table 1.

[0034] Table 1

[0035] Analysis of the data in the table above shows that Examples 1-3 exhibit superior and stable performance, comprehensively outperforming Comparative Examples 1-3. Their moisture content is significantly lower than 1000 ppm, the purity of acrylic acid and n-butanol is both >99%, and the purity of sodium sulfate meets Class I standards. Further analysis reveals that Comparative Example 1, lacking the molecular sieve membrane treatment, shows a sharp increase in moisture content and a corresponding decrease in acrylic acid purity. This indicates that without the crucial deep dehydration unit of the molecular sieve membrane, centrifugal extraction alone cannot reduce the moisture content to a low level. The high-moisture organic phase entering the subsequent ion exchange purification stage leads to resin poisoning, a rapid decrease in exchange capacity, and an inability to effectively remove metal ions, directly causing a significant reduction in the purity of the acrylic acid product. This also slightly affects the azeotropic distillation efficiency. The purity of n-butanol decreased slightly, while the purity of acrylic acid dropped drastically in Comparative Example 2 due to the lack of ion exchange purification, failing to meet the requirements for qualified products. This indicates that without resin treatment, trace metal ions in acrylic acid cannot be specifically adsorbed and removed, resulting in a significant reduction in product purity. This suggests that the ion exchange step has a significant impact on obtaining high-purity acrylic acid, but this step mainly targets the acrylic acid phase, so it has little impact on the purity of n-butanol. In Comparative Example 3, the lack of ultraviolet photocatalytic oxidation resulted in a severe deterioration in the quality of its byproduct, sodium sulfate. This is because the absence of the ultraviolet photocatalytic oxidation unit means that the recalcitrant organic matter in the wastewater was not effectively removed. These organic matter will be encapsulated in sodium sulfate crystals or adsorbed on the surface during the subsequent MVR evaporation and crystallization process, leading to a significant reduction in product color and purity.

[0036] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0037] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A highly efficient and environmentally friendly process for treating high-salt butyl acrylate wastewater, characterized in that: Includes the following steps: S1: Acidification and replacement. High-salt butyl acrylate wastewater is passed into a strong acid replacement reactor, concentrated sulfuric acid is added to adjust the pH, and the reaction is kept at a constant temperature. After the reaction is completed, the wastewater is cooled to 35°C through a heat exchanger to obtain pretreated wastewater. S2: Extraction and separation: The pretreated wastewater is passed into a centrifugal extractor. After centrifugal extraction, an oil phase and an aqueous phase are obtained. The oil phase is passed through a molecular sieve membrane to obtain an organic phase, while the aqueous phase is reserved for use. S3: Distillation and recovery: The aqueous phase is passed into a distillation column for azeotropic distillation. S4: Refining and purification: The organic phase is refined and reused in the production unit. S5: Neutralization and adjustment: The distillation column bottom wastewater generated in S3 is neutralized and adjusted to obtain a treated liquid. S6: Evaporation and crystallization. The treatment liquid is fed into the MVR evaporation system, and after preheating, evaporation and crystallization, sodium sulfate solid is separated.

2. The efficient and environmentally friendly butyl acrylate high-salt wastewater treatment process according to claim 1, characterized in that, In S1, the pH value is adjusted to 1.5-2.0 with concentrated sulfuric acid, and the reaction temperature is 60℃.

3. The efficient and environmentally friendly butyl acrylate high-salt wastewater treatment process according to claim 1, characterized in that, In S2, the pretreated wastewater is dehydrated to below 1000 ppm after passing through a centrifugal extractor.

4. The efficient and environmentally friendly butyl acrylate high-salt wastewater treatment process according to claim 1, characterized in that, The distillation recovery method is as follows: the aqueous phase is preheated to 65-70°C and then enters the distillation column. The working temperature is 110-120°C. An azeotrope of n-butanol and water is generated at the top of the column. After being condensed to 35°C by circulating water, condensation and separation occur. After condensation and separation, the butanol is reused, and the remaining material is partially recycled into the MVR evaporation system of S6.

5. The efficient and environmentally friendly butyl acrylate high-salt wastewater treatment process according to claim 4, characterized in that, The distillation column in S3 operates at a temperature of 110–120°C and a pressure of -0.1 MPaG, with the bottom wastewater containing 10–15% sodium sulfate.

6. The efficient and environmentally friendly butyl acrylate high-salt wastewater treatment process according to claim 1, characterized in that, The method for refining and purifying the organic phase is as follows: the organic phase is pumped into a continuous ion exchange device, and the organic phase is adsorbed using a resin adsorption column. The organic phase flows out from the bottom of the column to complete the refining and purification process, and the resulting product is recycled to the production equipment.

7. The efficient and environmentally friendly butyl acrylate high-salt wastewater treatment process according to claim 6, characterized in that, The resin adsorption column in S4 uses macroporous strong acid cation exchange resin, with an adsorption flow rate of 2–5 BV / h and an adsorption treatment temperature of 25–35℃.

8. The efficient and environmentally friendly butyl acrylate high-salt wastewater treatment process according to claim 1, characterized in that, The neutralization and adjustment method is as follows: the distillation column bottom wastewater generated in S3 is mixed and neutralized with sodium hydroxide solution in a static mixer, the pH value is adjusted to 6.5-7.5, the neutralized wastewater is passed into an oxidation reactor and treated under ultraviolet photocatalysis for 2-4 hours to obtain the treated liquid.

9. The efficient and environmentally friendly butyl acrylate high-salt wastewater treatment process according to claim 8, characterized in that, The sodium hydroxide solution in S5 has a mass concentration of 4-5%.

10. The efficient and environmentally friendly butyl acrylate high-salt wastewater treatment process according to claim 1, characterized in that, The evaporation crystallization method is as follows: the processing liquid is introduced into the MVR evaporation system, preheated to 85-90°C, and then the liquid enters the forced circulation evaporation crystallizer. The compressor inlet temperature is 90-95°C, the temperature rise is 15°C, and the steam flow rate is 1.2-1.5 t / h. The resulting product is thickened by a thickener and dehydrated by a centrifuge to obtain a wet material. The wet material then enters the fluidized bed drying and cooling system. After drying, sodium sulfate solid is obtained. The sodium sulfate is dried, packaged, and sold.

Images