Phenolic wastewater treatment process

Abstract

The invention provides a phenolic wastewater treatment process, and belongs to the technical field of chemical processes. Phenolic wastewater generated in the process of preparing bisphenol A through condensation reaction by taking phenol and acetone as raw materials is input into the upper part of an extraction tower, an extraction agent is input into the lower part of the extraction tower, and a water phase with the phenol content of less than 100ppm is extracted from a tower kettle of the extraction tower after counter-current extraction; a tower top extract of the extraction tower is subjected to dephenolization and then returns to the extraction tower to serve as an extraction agent to be recycled; wherein the feeding amount of the extraction agent is 5000 to 6000 kg / h, and the flow rate of phenol in the extraction agent is 0.5 to 1.3 kg / h. Meanwhile, main influence factors of the phenol content in the extraction tower kettle wastewater are comprehensively and systematically optimized, so that the phenol content in the extraction tower kettle is less than 100ppm, the phenol content in the phenol-containing wastewater is reduced, the environmental pollution is reduced, the phenol extracted from the top of the extraction tower can be recycled, and the resource waste is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of chemical processes, and in particular to a process for treating phenol-containing wastewater. Background Art

[0002] Bisphenol A (BPA) is a widely used chemical raw material for the production of polycarbonate, epoxy resin, polysulfone resin, polyphenylene ether resin, unsaturated polyester resin, etc. In industry, phenol and acetone are mainly used as raw materials, and condensation reaction occurs under the action of catalysts such as sulfuric acid, hydrogen chloride or strong acidic cation exchange resin for production. In the above industrial production process, phenol-containing wastewater is inevitably produced. Phenol is both an important solvent and an organic chemical raw material. Direct discharge of phenol-containing wastewater will not only pollute the environment, but also be detrimental to the recycling and utilization of phenol and the later refining of BPA. Therefore, in order to avoid wasting phenol, reduce cost losses, improve the purity of BPA products, and protect the environment, the recovery and treatment of phenol in BPA wastewater is imminent.

[0003] Researchers generally use macroporous resin adsorption to treat industrial phenol-containing wastewater. Hao Zhen et al. used salting-out-evaporation concentration to treat the desorption liquid of phenol wastewater with resin adsorption. The final phenol mass concentration was less than 2 mg / L, and through continuous cycle application operation, the phenol in the desorption liquid was completely separated and recovered. Qu Jiahui et al. used FeNi / D301 magnetic adsorption resin to treat phenol-containing wastewater. The adsorption amount was the largest when the initial phenol concentration was 100 mg / L, the adsorption temperature was 30°C, the pH value was 4, and the adsorption time was 3h. However, the macroporous resin adsorption method is costly and the phenol removal effect is not good.

[0004] In industry, phenol-containing wastewater can be directly removed by water washing, and multi-stage countercurrent extraction or multi-stage cross-current extraction can be used. In multi-stage countercurrent extraction, the direction of phenol-containing wastewater is opposite to that of the extractant, and the extractant is only added in the last stage. Compared with multi-stage cross-current extraction, the extractant consumption is less, the average concentration of the extract product is high, and the product yield is high. Therefore, multi-stage countercurrent extraction is generally used in industrial production to treat phenol-containing wastewater. Xie Huasheng and others conducted multi-stage countercurrent extraction and multi-stage cross-current extraction experiments to make the phenol content meet the separation requirements. Based on the experimental results, process simulation and material balance analysis were carried out, and the mass flow rate of phenol at the bottom of the tower was reduced to the required concentration. Finally, a modification plan for the tower diameter, tower plate spacing and flange was formulated for the existing water washing tower.

[0005] It is worth noting that although researchers have adopted a variety of methods to treat phenol-containing wastewater, the problem of excessively high phenol content still exists in large-scale industrial phenol-containing wastewater treatment processes. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention discloses a process for treating phenol-containing wastewater. The process uses countercurrent extraction. After comprehensive and systematic optimization, the phenol content in the bottom of the extraction tower after extraction is less than 100 ppm, thereby reducing the phenol content in the wastewater. The phenol extracted from the top of the extraction tower is beneficial to the recovery and utilization of phenol and the later refining of BPA.

[0007] In order to achieve the above technical objectives, the present invention proposes a phenol-containing wastewater treatment process, wherein the phenol-containing wastewater generated in the process of preparing bisphenol A by condensation reaction with phenol and acetone as raw materials is input into the upper part of the extraction tower, and the extractant is input into the lower part of the extraction tower. After countercurrent extraction, an aqueous phase with a phenol content of less than 100 ppm is extracted from the kettle of the extraction tower, and the extracted material from the top of the extraction tower is returned to the extraction tower as an extractant for recycling after dephenolization; wherein the feed amount of the extractant is 5000-6000 kg / h, and the phenol flow rate in the extractant is 0.5-1.3 kg / h.

[0008] The research and development team of the present invention has found, based on a large amount of data calculation and production practice experience, that the feed amount of the extractant in the phenol-containing wastewater treatment process of the present invention can enhance the extraction effect. By increasing the feed amount of the extractant, the contact area between the extractant and the phenol in the wastewater can be increased, thereby accelerating the extraction rate and improving the extraction efficiency. In addition, since the extractant used in the present invention is recycled, the phenol-containing organic phase is extracted from the top of the extraction tower, which contains most of the extractant, and after being dephenolized by distillation and separation in the extractant recovery tower, it is returned to the lower part of the extraction tower for recycling as an extractant. However, the recycled extractant still contains phenol, so it is necessary to control the phenol flow rate in the extractant within a certain range so that it has a better extraction effect.

[0009] Furthermore, based on the two main influencing factors of the feed amount of the extractant and the phenol flow rate in the extractant, the research and development team of the present invention uses multiple factors to calculate the influence of the phenol content in the tower bottom wastewater. After calculation, when the feed amount of the extractant is 5000-6000 kg / h and the phenol flow rate in the extractant is 0.5-1.3 kg / h, the phenol content in the tower bottom of the extraction tower in the above technical scheme is less than 100 ppm, which reduces the phenol content in the phenol-containing wastewater and reduces environmental pollution. At the same time, the phenol extracted from the top of the extraction tower can be recycled to reduce resource waste. The embodiment of the present invention shows the technical effect of the parameter optimization of the feed amount of the extractant of the extraction tower and the phenol flow rate in the extractant.

[0010] The method of preparing bisphenol A by condensation reaction with phenol and acetone as raw materials is well known to technicians in the technical field, including sulfuric acid method, hydrochloric acid method and ion exchange resin method. The sulfuric acid method is a traditional method, using sulfuric acid as a catalyst, phenol, acetone and sulfuric acid are mixed in a certain proportion, reacted at 30° C. to 40° C. for 4 to 6 hours, and then filtered, washed, neutralized and centrifuged to obtain bisphenol A; the hydrochloric acid method uses hydrogen chloride as a catalyst, the reaction is carried out at 60-65° C., and the product is refined by distillation and recrystallization; the ion exchange resin method uses a strong acid cation exchange resin as a catalyst, the reaction is carried out at 75° C., and the product is purified by distillation and crystallization separation.

[0011] The phenol-containing wastewater described in the present invention mainly comes from the following links: (1) Condensation reaction link: phenol and acetone undergo condensation reaction in an acidic medium. In this process, unreacted phenol may dissolve in water to form phenol-containing wastewater. (2) Dehydration link: After the condensation reaction, it is usually necessary to remove the water generated by the reaction by distillation or evaporation. The wastewater generated in these processes may also contain phenolic substances. (3) Crystallization and separation link: During the purification of bisphenol A, water or other solvents may be used in the crystallization and separation steps. These solvents will become phenol-containing wastewater in subsequent treatments.

[0012] Furthermore, the feed rate of the extractant is 5500-6000 kg / h, and the flow rate of phenol in the extractant is 0.6-0.9 kg / h. Within this range, the phenol content in the bottom of the extraction tower is less than 80 ppm, further reducing the phenol content in the phenol-containing wastewater.

[0013] Furthermore, the number of theoretical plates of the extraction tower is 6 to 15. The number of theoretical plates is an important indicator for measuring the separation effect of the extraction tower. Controlling the number of theoretical plates can improve the separation efficiency of phenol and other components in wastewater, thereby more effectively removing phenol and improving the quality of treated water. At the same time, by controlling the number of theoretical plates, it can ensure that the extractant is fully in contact with the phenol in the wastewater, improve the utilization rate of the extractant, and reduce the consumption and cost of the extractant.

[0014] Furthermore, the number of theoretical plates of the extraction tower is 7 to 9. Within this range, the phenol content in the bottom of the extraction tower is less than 80 ppm. The embodiment of the present invention shows the technical effect of parameter optimization of the number of theoretical plates of the extraction tower.

[0015] Furthermore, the phenol flow rate in the phenol-containing wastewater is 50 to 115 kg / h, preferably 100 to 115 kg / h. By precisely controlling the phenol flow rate in the wastewater, effective contact and mass transfer between the extractant and the phenol-containing wastewater can be ensured, thereby improving the extraction efficiency of phenol; while controlling the wastewater flow rate helps to regulate the fluid mechanics behavior in the tower, such as the dispersion and merging of droplets, thereby affecting the droplet holdup and droplet diameter distribution, which further affects the mass transfer efficiency. The embodiment of the present invention shows the technical effect of parameter optimization of the phenol flow rate in phenol-containing wastewater.

[0016] Furthermore, the temperature of the extractant is 0 to 30° C., preferably 20 to 25° C. The extractant may decompose at too high a temperature, affecting the extraction efficiency. When the temperature of the extractant is within a certain range, the dissolution and diffusion of the substance can be promoted, thereby improving the extraction efficiency. The embodiment of the present invention shows the technical effect of parameter optimization of the extractant temperature.

[0017] Furthermore, the feed temperature of the phenol-containing wastewater is 0 to 30°C, preferably 20 to 25°C. The temperature of the phenol-containing wastewater directly affects the solubility and mass transfer rate of phenol during the extraction process. At a suitable temperature, the solubility of phenol in the extractant increases, thereby improving the extraction efficiency. The embodiment of the present invention shows the technical effect of parameter optimization of the feed temperature of the phenol-containing wastewater.

[0018] Furthermore, the top outlet temperature of the extraction tower is 25-30°C, and the pressure is 5-8 bar. The research and development team of the present invention found through simulation calculation of material balance that when the top outlet temperature and pressure of the extraction tower are within a certain range, a high content of phenol can be extracted from the top of the tower for phenol recycling. The embodiment of the present invention shows the technical effect of the parameter optimization of the top outlet temperature and pressure of the extraction tower.

[0019] Furthermore, the extraction tower is a packed tower, and the packing of the packed tower is a random packing. Random packing helps to increase the gas-liquid contact area, improve the gas-liquid distribution, and thus improve the mass transfer efficiency; random packing usually has a large porosity, which is conducive to the flow of gas and liquid, so during the entire operation, the pressure drop is relatively low, reducing energy consumption; compared with structured packing, random packing has a lower cost, which can reduce production costs. Furthermore, the random packing can be selected as a flat ring packing. In the embodiment of the present invention, hydraulic analysis is performed to explore the process conditions and technical effects of the extraction tower using flat ring packing.

[0020] Furthermore, the extractant is any one or more of isopropyl ether, methyl isobutyl ketone, butyl acetate or methyl pentenone, preferably isopropyl ether; by selecting an efficient, economical, environmentally friendly and easy-to-operate extractant, the treatment effect of phenol-containing wastewater can be significantly improved and the treatment cost can be reduced.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: in the phenol-containing wastewater treatment process provided by the present invention, the extractant feed amount and the phenol flow rate in the extractant are the main factors affecting the extraction efficiency. By controlling the extractant feed amount and the phenol flow rate in the extractant, the factors affecting the phenol content in the bottom wastewater are comprehensively and systematically optimized, so that the phenol content in the bottom of the extraction tower after extraction is less than 100 ppm, the phenol content in the phenol-containing wastewater is reduced, and environmental pollution is reduced. At the same time, the phenol extracted from the top of the extraction tower can be recycled to reduce resource waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 The effect of the extractant feed amount on the phenol content in the extraction tower bottom wastewater in Example 1 of the present invention is shown;

[0024] Figure 2 The effect of the phenol flow rate in the extractant in Example 1 of the present invention on the phenol content in the wastewater from the extraction tower bottom is shown;

[0025] Figure 3 The effect of the theoretical plate number of the extraction tower in Example 2 of the present invention on the phenol content in the wastewater from the extraction tower kettle is shown;

[0026] Figure 4 The effect of the phenol flow rate in the phenol-containing wastewater on the phenol content in the wastewater from the extraction tower bottom in Example 3 of the present invention is shown;

[0027] Figure 5 The effect of the extractant temperature on the phenol content in the wastewater from the extraction tower bottom in Example 4 of the present invention is shown;

[0028] Figure 6 The effect of the feed temperature of the phenol-containing wastewater in Example 5 of the present invention on the phenol content of the wastewater in the bottom of the extraction tower is shown. DETAILED DESCRIPTION

[0029] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below, and preferred embodiments of the present invention are given. However, it should be understood that these embodiments are only used for more detailed description, and should not be understood as limiting the present invention in any form, that is, not limiting the scope of protection of the present invention. Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs.

[0030] Example 1

[0031] A phenol-containing wastewater treatment process comprises: the phenol-containing wastewater generated in the process of preparing bisphenol A by condensation reaction with phenol and acetone as raw materials is input into the upper part of an extraction tower, an extractant is input into the lower part of the extraction tower, an aqueous phase with a phenol content of less than 100 ppm is extracted from the kettle of the extraction tower after countercurrent extraction, and the extracted material from the top of the extraction tower is returned to the extraction tower for recycling as an extractant after dephenolization; wherein the feed amount of the extractant is 5000-6000 kg / h, and the phenol flow rate in the extractant is 0.5-1.3 kg / h.

[0032] The research and development team of the present invention used isopropyl ether as the extractant. When the phenol flow rate in the extractant was 0.85 kg / h, the effect of the extractant feed rate on the phenol content in the extraction tower reactor wastewater was investigated. The results are as follows Figure 1 As shown, as the feed amount of the extractant isopropyl ether increases, the phenol content of the tower bottom wastewater decreases rapidly. When the feed amount of the extractant is within the range of 5000-6000kg / h, the phenol content in the tower bottom wastewater is less than 100ppm. When the feed amount of the extractant is 4900kg / h, the phenol content in the tower bottom wastewater is 97.9ppm, which is 18.3% of the phenol content (97.9ppm) in the tower bottom wastewater when the feed amount of the extractant is 3000kg / h, and meets the requirement that the phenol content after extraction is less than 100ppm. Therefore, the feed amount of the extractant has a greater influence on the phenol content in the tower bottom wastewater. The greater the feed amount of the extractant, the lower the phenol content in the tower bottom wastewater. It is further preferably 5500-6000kg / h, and the phenol content in the tower bottom wastewater is less than 80ppm within this range.

[0033] Furthermore, the research and development team of the present invention used isopropyl ether as the extractant, and when the feed rate of the extractant was 5500 kg / h, the effect of the phenol flow rate in the extractant on the phenol content of the extraction tower reactor wastewater was investigated. The results are as follows: Figure 2 As shown, as the phenol flow rate in the extractant increases, the phenol content in the tower bottom wastewater increases. When the phenol flow rate in the extractant is 1.3kg / h, the phenol content in the tower bottom wastewater is 97.4ppm, which is 2.6 times and 55.3% of the phenol content in the tower bottom wastewater (37.1ppm and 176.0ppm) when the phenol flow rate in the extractant is 0kg / h and 3kg / h. When the phenol flow rate in the extractant is 0.5-1.3kg / h, it meets the requirement that the phenol content after extraction is less than 100ppm. The above results show that the phenol flow rate in the extractant has a greater impact on the phenol content in the tower bottom wastewater. The lower the phenol content in the extractant, the lower the phenol content in the tower bottom wastewater. It is further preferably 0.6-0.9kg / h, and the phenol content in the tower bottom wastewater is less than 80ppm within this range.

[0034] Optionally, the extractant is any one or more of isopropyl ether, methyl isobutyl ketone, butyl acetate or methyl pentenone, preferably isopropyl ether.

[0035] Example 2

[0036] Based on a phenol-containing wastewater treatment process shown in Example 1, this example shows the optimization process of the control conditions of the theoretical plate number of the extraction tower.

[0037] The research and development team of the present invention used isopropyl ether as the extractant, the phenol flow rate in the extractant was 0.85 kg / h, and the extractant feed rate was 5500 kg / h. The effect of the theoretical plate number of the extraction tower on the phenol content of the extraction tower kettle wastewater was investigated. The results are as follows Figure 3 As shown, when the number of theoretical plates is 6 to 15, as the number of theoretical plates increases, the phenol content in the tower bottom wastewater decreases rapidly. When the number of theoretical plates is 8, the phenol content in the tower bottom wastewater (54.1ppm) is 19.2% of that when the number of theoretical plates is 4 (282.5ppm). As the number of theoretical plates continues to increase, the fluctuation of the phenol content in the tower bottom wastewater is small. When the number of theoretical plates is 6 or more, the phenol content in the tower bottom wastewater meets the requirement that the phenol content after extraction is less than 100ppm. The above results show that the number of theoretical plates has a greater influence on the phenol content in the tower bottom wastewater, and it is further preferred to be 7 to 9, within which the phenol content in the tower bottom wastewater is less than 80ppm.

[0038] Example 3

[0039] Based on a phenol-containing wastewater treatment process shown in Example 1, this example shows the optimization process of the phenol flow control conditions in the phenol-containing wastewater.

[0040] The research and development team of the present invention used isopropyl ether as the extractant, the phenol flow rate in the extractant was 0.85 kg / h, and the extractant feed rate was 5500 kg / h to investigate the effect of the phenol flow rate in the phenol-containing wastewater on the phenol content in the extraction tower reactor wastewater. The results are as follows Figure 4 As shown, as the phenol flow rate in the phenol-containing wastewater increases, the phenol content in the bottom wastewater increases. When the phenol flow rate in the phenol-containing wastewater is 200kg / h, the phenol content in the bottom wastewater (99.3ppm) is 1.6 times the phenol content in the bottom wastewater (62.4ppm) when the phenol flow rate in the phenol-containing wastewater is 50kg / h. When the phenol flow rate in the phenol-containing wastewater is 50-115kg / h, the phenol content in the bottom wastewater meets the requirement that the phenol content after extraction is less than 100ppm. More preferably, it is 100-115kg / h, and the phenol content in the bottom wastewater is less than 80ppm within this range.

[0041] Example 4

[0042] Based on a phenol-containing wastewater treatment process shown in Example 1, this example shows the optimization process of the extractant temperature control conditions.

[0043] The research and development team of the present invention used isopropyl ether as the extractant, the phenol flow rate in the extractant was 0.85 kg / h, and the extractant feed rate was 5500 kg / h. The effect of the extractant temperature on the phenol content of the extraction tower reactor wastewater was investigated. The results are as follows Figure 5 As shown, as the feed temperature of the extractant isopropyl ether increases, the phenol content of the bottom wastewater increases. When the feed temperature is 60°C, the phenol concentration of the bottom wastewater is 87.6ppm, which is 1.1 times the phenol concentration (83.4ppm) of the bottom wastewater when the feed temperature is 0°C. The above results show that the feed temperature of the extractant has little effect on the phenol content in the bottom wastewater, but low temperature is conducive to extraction. Therefore, the extractant temperature of the extraction tower is 0-30°C, more preferably 22-25°C, within which the phenol content in the bottom wastewater is less than 85ppm.

[0044] Example 5

[0045] Based on a phenol-containing wastewater treatment process shown in Example 1, this example shows the optimization process of the phenol-containing wastewater feed temperature control conditions.

[0046] The research and development team of the present invention used isopropyl ether as the extractant, the phenol flow rate in the extractant was 0.85 kg / h, and the extractant feed rate was 5500 kg / h. The effect of the feed temperature of the phenol-containing wastewater on the phenol content of the extraction tower reactor wastewater was investigated. The results are as follows Figure 6 As shown, as the feed temperature of phenol-containing wastewater increases, the phenol content of the bottom wastewater increases. When the feed temperature is 60°C, the phenol concentration of the bottom wastewater is 113.7ppm, which is 1.5 times the phenol concentration (74.5ppm) of the bottom wastewater when the feed temperature is 0°C. The above results show that the feed temperature of phenol-containing wastewater has little effect on the phenol content in the bottom wastewater, but low temperature is conducive to extraction. Therefore, the feed temperature of phenol-containing wastewater is 0-30°C, and more preferably 22-25°C. Within this range, the phenol content in the bottom wastewater is less than 80ppm.

[0047] Example 6

[0048] Based on a phenol-containing wastewater treatment process shown in Example 1, this example shows the optimization process of the temperature and pressure control conditions at the top outlet of the extraction tower.

[0049] The research and development team of the present invention uses isopropyl ether as the extractant, the phenol flow rate in the extractant is 0.85kg / h, and the feed amount of the extractant is 5500kg / h. The material balance of the phenol extraction tower is performed. The theoretical number of plates of the extraction tower is 6 (the extraction tower has six sections of random packing, and the section height is 3.05m), the top temperature of the extraction tower is 29.8°C, and the top pressure is 5.6bar. The calculated phenol content in the bottom wastewater is 85ppm, and the material balance related data are shown in Table 1. When the top outlet temperature of the extraction tower is 25-30°C and the top pressure is in the range of 5-8bar, the phenol content in the bottom wastewater of the extraction tower is 85ppm, and the phenol content in the bottom wastewater meets the requirement that the phenol content after extraction is less than 100ppm.

[0050] Table 1 Material balance table

[0051]

[0052]

[0053] Example 7

[0054] Based on a phenol-containing wastewater treatment process shown in Example 1, the tower filler is a random packing, which is calculated as a flat ring packing and has a specification of 38 mm. The tower diameter and hydraulics of the extraction tower are calculated. According to the tower diameter DN1200, when the operating load is within the range of 60% to 100%, the flooding rate of the continuous phase and the dispersed phase are both within the normal use range. Therefore, the larger porosity of the random packing is conducive to the flow of gas and liquid. During the entire operation process, the velocity distribution of the continuous phase in the flow direction will not be uneven, causing the turbulence and vortex of the continuous phase to cause the back mixing and entrainment of the dispersed phase droplets, and then axial mixing occurs, and the phenol content in the wastewater of the extraction tower kettle increases.

[0055] Table 2 Tower diameter and hydraulic calculation

[0056]

[0057]

[0058] It should be noted that the above contents are further detailed descriptions of the present invention in combination with specific implementation methods, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple improvements and modifications can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A process for treating phenol-containing wastewater, characterized in that: Phenolic wastewater generated in the process of preparing bisphenol A through condensation reaction using phenol and acetone as raw materials is input into the upper part of an extraction tower, an extractant is input into the lower part of the extraction tower, an aqueous phase with a phenol content of less than 100 ppm is extracted from the kettle of the extraction tower after countercurrent extraction, and the extract from the top of the extraction tower is returned to the extraction tower after dephenolization and recycled as an extractant; wherein the feed amount of the extractant is 5000-6000 kg / h, and the phenol flow rate in the extractant is 0.5-1.3 kg / h.

2. A phenol-containing wastewater treatment process according to claim 1, characterized in that: The feed rate of the extractant is 5500-6000 kg / h, and the flow rate of phenol in the extractant is 0.6-0.9 kg / h.

3. A phenol-containing wastewater treatment process according to claim 1, characterized in that: The extraction tower has 6 to 15 theoretical plates.

4. A phenol-containing wastewater treatment process according to claim 3, characterized in that: The extraction tower has 7 to 9 theoretical plates.

5. A phenol-containing wastewater treatment process according to claim 1, characterized in that: The phenol flow rate in the phenol-containing wastewater is 50 to 115 kg / h, preferably 100 to 115 kg / h.

6. A phenol-containing wastewater treatment process according to claim 1, characterized in that: The temperature of the extractant is 0-30°C, preferably 20-30°C.

7. A phenol-containing wastewater treatment process according to claim 1, characterized in that: The feed temperature of the phenol-containing wastewater is 0-30°C, preferably 20-25°C.

8. A phenol-containing wastewater treatment process according to claim 1, characterized in that: The extraction tower top outlet temperature is 25-30° C., and the pressure is 5-8 bar.

9. A phenol-containing wastewater treatment process according to claim 1, characterized in that: The extraction tower is a packed tower, and the packing of the packed tower is a random packing.

10. A phenol-containing wastewater treatment process according to claim 1, characterized in that: The extractant is any one or more of isopropyl ether, methyl isobutyl ketone, butyl acetate or methyl pentenone, preferably isopropyl ether.

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