High-phenol wastewater treatment system and method

Abstract

A high-phenol wastewater treatment system, comprising a wet oxidation reactor (1), wherein a first mass-transfer intensification unit (2) is provided outside the wet oxidation reactor (1), a second mass-transfer intensification unit (3) is provided inside the wet oxidation reactor (1), the first mass-transfer intensification unit (2) is connected to the second mass-transfer intensification unit (3), and the second mass-transfer intensification unit (3) is arranged at the lower middle part of the wet oxidation reactor (1). The treatment system combines the mass-transfer intensification units with a reaction system, and breaks and disperses wastewater and gas into micro-bubbles by means of the mass-transfer intensification units, thereby improving the mass-transfer effect between the wastewater and the gas, improving the reaction efficiency and also reducing the reaction temperature and pressure.

Description

A Treatment System and Method for High-Phenol Wastewater Technical Field The present invention belongs to the technical field of wastewater treatment, and more specifically, to a treatment system and method for high-phenol wastewater. Background Art Phenol-containing industrial wastewater mainly comes from industries such as petrochemical industry, coking chemical industry, papermaking, pharmaceuticals, and phenolic resins. Due to the differences in industrial types and production processes, there are significant differences in the types and concentrations of phenolic substances and other pollutants in the wastewater. Phenolic compounds pose a serious threat to the environment and human health due to their high biological toxicity. They can react with proteins, causing protein denaturation and making biological cells lose their activity. In the human body, high concentrations of phenolic compounds can cause serious local damage, while low concentrations of phenolic compounds may penetrate into the body, causing central nervous and spinal cord injuries and resulting in systemic poisoning symptoms. Therefore, phenolic wastewater must be effectively treated and degraded to safe levels before being discharged to reduce the threat to the environment and human health. Currently, the treatment methods for phenolic wastewater mainly include adsorption, extraction, oxidation, and biological technologies. These methods need to be selected according to the phenol concentration and the content of other substances in the wastewater in practical applications. However, there are many problems with existing treatment technologies. For example, traditional wet oxidation methods need to be carried out under high temperature and high pressure conditions, and usually require the addition of catalysts. This method directly oxidizes and degrades the organic matter in the wastewater, but has high requirements for equipment, large catalyst losses, and low removal rates of phenolic substances. This results in high energy consumption, low reaction efficiency, and unsatisfactory treatment effects during the treatment process. Therefore, the development of a phenolic wastewater treatment technology with higher energy efficiency, better reaction efficiency, and more effective treatment has become an important requirement in the current environmental protection field. In view of this, the present invention is specifically proposed. Summary of the Invention The first object of the present invention is to provide a treatment system for high-phenol wastewater, which combines a mass transfer intensification unit with a reaction system. The mass transfer intensification unit breaks and disperses the wastewater and gas in the wet oxidation reactor into microbubbles, improving the mass transfer effect between the wastewater and the gas, enhancing the reaction efficiency, and simultaneously reducing the reaction temperature and pressure. The second object of the present invention is to provide a method for treating high-phenol wastewater using the above treatment system. This method is simple to operate, has milder operating conditions, low energy consumption, and achieves a better treatment effect than existing technical processes. To achieve the above objects of the present invention, the following technical solutions are specifically adopted: The present invention provides a treatment system for high-phenol wastewater, comprising: A wet oxidation reactor and a deep oxidation tower; A first mass transfer intensification unit is arranged outside the wet oxidation reactor, a second mass transfer intensification unit is arranged inside the wet oxidation reactor, the first mass transfer intensification unit is connected to the second mass transfer intensification unit, and the second mass transfer intensification unit is arranged in the middle and lower part of the wet oxidation reactor; The bottom end of the deep oxidation tower is connected to the top end of the wet oxidation reactor, and a third mass transfer intensification unit is arranged inside the deep oxidation tower. In the prior art, the treatment system for high-phenol wastewater mainly has the following problems: The traditional wet oxidation method needs to be carried out under high temperature and high pressure conditions, and at the same time, the removal rate of phenolic substances in the wastewater is not high. To solve the above technical problems, the present invention provides a treatment system for high-phenol wastewater. The overall structure of the treatment system is simple. By integrating a wet oxidation reactor and a deep oxidation tower, continuous oxidation treatment is realized, greatly enhancing the decomposition efficiency of organic substances, especially high-phenol compounds; preliminary oxidation is provided by the wet oxidation reactor, and the deep oxidation tower further enhances the oxidation effect to ensure the thorough treatment of refractory substances. By respectively arranging a first mass transfer intensification unit and a second mass transfer intensification unit outside and inside the wet oxidation reactor, the high-phenol wastewater and oxygen entering the inside of the wet oxidation reactor can be broken and dispersed, the phase boundary mass transfer area of the gas-liquid two-phase can be increased, the solubility and distribution of oxygen in the liquid phase can be enhanced, thereby accelerating the reaction process; by arranging a third mass transfer intensification unit inside the deep oxidation tower, the phase boundary mass transfer area of the gas-liquid two-phase in the deep oxidation tower can be increased, the deep oxidation reaction can be promoted, and at the same time, the reaction temperature and pressure can be reduced. Preferably, the first mass transfer intensification unit includes a first intensification reactor connected to the wastewater storage tank and a second intensification reactor connected to the high-pressure gas pipeline. The first intensification reactor is arranged above the second intensification reactor, and a communication pipeline is arranged between the first intensification reactor and the second intensification reactor. The first intensification reactor of the present invention is arranged above the second intensification reactor because the first intensification reactor is connected to the wastewater storage tank and the second intensification reactor is connected to the high-pressure gas. Arranging the first intensification reactor above the second intensification reactor can utilize the inertia of the wastewater to move downward, and at the same time utilize the fact that the density of the gas is lower than that of the wastewater to make the gas move upward, thereby increasing the gas-liquid contact time and contact area. Preferably, a stirrer is arranged inside the communication pipeline, and the stirrer is arranged at two ports of the communication pipeline. Specifically, the stirrer in the present invention is a spherical stirrer, which includes a stirring rod and a plurality of stirring wires arranged circumferentially around the stirring rod. The distance between adjacent stirring wires is equal, and the stirring wires are all arranged in a curved shape. In the present invention, a stirrer is arranged inside the connecting pipeline, which can fully stir and mix the mixed materials inside the connecting pipeline. At the same time, the stirrers are respectively arranged at the outlets of the first intensifying reactor and the second intensifying reactor, which can be used in cooperation with the intensifying reactors to break and disperse the microbubbles coming out of the intensifying reactors in time, make them more evenly distributed inside the whole connecting pipeline, and prevent the coalescence phenomenon at the outlets of the intensifying reactors. Shearing force and turbulence are generated by the stirrers to prevent or reduce the coalescence phenomenon and improve the mass transfer efficiency of the system. The distances between adjacent stirring wires in the present invention are equal. The advantage of such a setting is that during the process of stirring and mixing by the stirrer, the forces on each stirring wire are uniform, the deformation amount of the stirring wire is reduced, and at the same time, the effect of uniform mixing is achieved. Preferably, the second mass transfer intensifying unit includes a third intensifying reactor arranged at the bottom end of the wet oxidation reactor. The third intensifying reactor is connected to the connecting pipeline, and the third intensifying re actor is provided with a gas-liquid distribution assembly at its outlet. The third intensifying reactor of the present invention is connected to the connecting pipeline to perform secondary breaking and dispersion on the mixed materials entering the wet oxidation reactor, achieving the effect of sufficient breaking and improving the reaction rate. By arranging the gas-liquid distribution assembly at the outlet of the third intensifying reactor, it can be used in cooperation with the third intensifying reactor to evenly distribute the microbubbles coming out of the third intensifying reactor inside the wet oxidation reactor, thereby maximizing the contact efficiency between gas and liquid, accelerating the mass transfer and reaction process; and at the same time improving the utilization rate of gas. Preferably, the gas-liquid distribution assembly includes a distribution plate and a support grid located above the distribution plate. A plurality of guide plates are connected to the lower surface of the support grid, and the angle between the guide plate and the lower surface of the support grid is 60-90°. Specifically, the inclination directions of the guide plates are the same. Specifically, the distribution plate is connected to the outlet of the third intensifying reactor to evenly diffuse the microbubbles coming out of the third intensifying reactor inside the whole wet oxidation reactor. At the same time, a support grid is arranged above the distribution plate, which can play a role in supporting and bearing. By arranging the guide plates below the support grid, the gas-liquid mixing can be strengthened. By setting the inclination angle of the guide plates, on the one hand, the reaction time can be prolonged to make the wastewater and the oxidation gas fully mix and react; on the other hand, the mixed materials inside the wet oxidation reactor can be dispersed, the air flow direction can be controlled, and the reaction pressure can be reduced. Preferably, the second mass transfer intensification unit further includes a fourth intensification reactor disposed at the middle position of the wet oxidation reactor. The fourth intensification reactor is connected to the high-pressure gas pipeline, and an aeration disk is disposed below the outlet of the fourth intensification reactor. By providing the fourth intensification reactor and connecting it to the high-pressure gas pipeline, sufficient gas is charged into the wet oxidation reactor to fully oxidize the wastewater. At the same time, the fourth intensification reactor is used in conjunction with the aeration disk to provide power for the gas microbubbles coming out of the fourth intensification reactor, thereby improving the gas conversion rate. Preferably, a first demisting disk, a diffusion disk, and a second demisting disk are sequentially arranged from bottom to top above the second mass transfer intensification unit; The first demisting disk includes a support disk, a first layer of metal mesh, and a second layer of metal mesh from bottom to top. By providing the demisting disk and the diffusion disk above the second mass transfer intensification unit, most of the foam in the wastewater to be discharged from the wet oxidation reactor is removed. The mixed material with a small amount of foam is evenly distributed by the diffusion disk and then the remaining foam is removed by the upper demisting disk, and then enters the preheating unit for heat exchange, and then enters the deep oxidation tower for deep oxidation reaction. The advantage of providing the demisting disk in the present invention is that it can remove the large bubbles in the mixed material and avoid uneven heating. In the present invention, a diffusion disk is provided between the two demisting disks, which can cooperate with the two demisting disks to more evenly distribute the gas coming out of the first demisting disk below to the second demisting disk, improving the processing efficiency of the overall system; at the same time, the gas is redistributed and homogenized before entering the second demisting disk, improving the demisting efficiency. Preferably, the third mass transfer intensification unit includes a fifth intensification reactor disposed at the bottom end of the deep oxidation tower and a sixth intensification reactor disposed above the fifth intensification reactor; the sixth intensification reactor is connected to the gas-liquid mixture coming out of the top end of the wet oxidation reactor; the fifth intensification reactor is connected to the ozone storage tank. Preferably, the outlets of the fifth intensification reactor and the sixth intensification reactor are oppositely arranged, and high-pressure nozzles are respectively connected to the outlets of the fifth intensification reactor and the sixth intensification reactor. In the present invention, by providing the third mass transfer intensification unit in the deep oxidation tower, the refractory organic matter can be further intensively treated. At the same time, the fifth intensification reactor of the present invention is connected to the ozone storage tank and disposed at the bottom of the deep oxidation tower, which is to make full use of the ozone gas. By disposing the fifth intensification reactor at the bottom of the reactor, the reaction time of ozone can be increased, so as to fully oxidize the organic matter in the wastewater and effectively remove the COD content in the wastewater. By providing high-pressure nozzles at the outlets of the fifth intensifying reactor and the sixth intensifying reactor, the fifth intensifying reactor and the sixth intensifying reactor can be made to oppose each other. Through the high-speed jet of the high-pressure nozzles, strong turbulence is formed for the microbubbles coming out of the intensifying reactors, promoting full and uniform mixing. Preferably, a first heat exchanger and a throttle valve are provided on the connecting pipe connecting the fifth intensifying reactor and the top of the wet oxidation reactor. In the present invention, by providing the throttle valve, the high pressure energy of the high-pressure gas-liquid two-phase flow coming out of the wet oxidation reactor can be converted into cold energy, rapidly reducing the temperature inside the tower. It can further cool down the high-temperature oxidation liquid coming out of the wet oxidation reaction tower, saving energy and reducing energy consumption. At the same time, the present invention uses a throttle valve as a component for further cooling, without the need for other cold sources for heat exchange, saving energy and water. Preferably, a circulation pipe is provided outside the deep oxidation tower. The inlet of the circulation pipe is connected to the water outlet at the middle position of the deep oxidation tower, and the outlet of the circulation pipe is connected to the sixth intensifying reactor; Preferably, a second heat exchanger and a circulation pump are provided on the circulation pipe. Those skilled in the art can understand that the intensifying reactor adopted in the present invention has been reflected in the prior patents of the present inventor, such as the patents with application numbers CN201610641119.6, CN201610641251.7, CN201710766435.0, CN106187660, CN105903425A, CN109437390A, CN205833127U, and CN207581700U. The prior patent CN201610641119.6 details the specific product structure and working principle of the microbubble generator (i.e., the intensifying reactor). The application document records that "the microbubble generator includes a main body and a secondary fragmentation member. There is a cavity inside the main body. The main body is provided with an inlet communicating with the cavity. Opposite first and second ends of the cavity are both open. The cross-sectional area of the cavity decreases from the middle of the cavity towards the first and second ends of the cavity; the secondary fragmentation member is provided at at least one of the first and second ends of the cavity. A part of the secondary fragmentation member is provided inside the cavity. An annular channel is formed between the secondary fragmentation member and the through holes that are open at both ends of the cavity. The microbubble generator further includes an air inlet pipe and a liquid inlet pipe." From the specific structure disclosed in this application document, its specific working principle can be known: the liquid tangentially enters the microbubble generator through the liquid inlet pipe, rotates at an ultra-high speed and cuts the gas, causing the gas bubbles to break into microbubbles at the micron level, thereby increasing the mass transfer area between the liquid phase and the gas phase. Moreover, the microbubble generator in this patent belongs to a pneumatic intensifying reactor. In addition, the prior patent 201610641251.7 records that the primary bubble breaker has a circulating liquid inlet, a circulating gas inlet and a gas-liquid mixture outlet, and the secondary bubble breaker connects the feed port with the gas-liquid mixture outlet, indicating that the bubble breaker requires gas-liquid mixture to enter. In addition, it can be seen from the following figures that the primary bubble breaker mainly uses circulating liquid as power, so in fact the primary bubble breaker belongs to a hydraulic enhanced reactor, and the secondary bubble breaker simultaneously passes the gas-liquid mixture into the elliptical rotating ball for rotation, thereby achieving bubble breaking during the rotation process, so the secondary bubble breaker actually belongs to a gas-liquid linkage enhanced reactor. In fact, both the hydraulic enhanced reactor and the gas-liquid linkage enhanced reactor are a specific form of enhanced reactor, however, the enhanced reactor adopted by the present invention The chemical reactor is not limited to the above-mentioned forms. The specific structure of the bubble breaker recorded in the previous patent is only one of the forms that can be adopted by the enhanced reactor of the present invention. In addition, the prior patent 201710766435.0 states that "the principle of the bubble breaker is to use high-speed jets to achieve gas collisions", and also explains that it can be used in a micro-interface enhanced reactor, verifying the correlation between the bubble breaker and the micro-interface generator; and the prior patent CN106187660 also has relevant records on the specific structure of the bubble breaker, see the specification for details.

[0031] -

[0041] , as well as the accompanying drawings, provide a detailed explanation of the specific working principle of the bubble breaker S-2. The top of the bubble breaker is a liquid phase inlet, and the side is a gas phase inlet. The liquid phase entering from the top provides suction power, thereby achieving the effect of crushing into ultra-fine bubbles. The accompanying drawings also show that the bubble breaker has a conical structure, with the upper part having a larger diameter than the lower part, so that the liquid phase can better provide suction power. Because the enhanced reactor was newly developed in the early stages of the prior patent application, it was initially named the micron bubble generator (CN201610641119.6) and the bubble breaker (201710766435.0). With continuous technological improvements, it was later renamed the enhanced reactor. The enhanced reactor in the present invention is equivalent to the previous micron bubble generator, bubble breaker, etc., only with a different name. In summary, the enhanced reactor of the present invention belongs to the prior art. Preferably, it further includes a wastewater filter, a preheating unit, an exhaust gas processor, and an ion membrane electrolyzer; The wastewater filter is connected to the preheating unit and to the wet oxidation reactor; The preheating unit includes a primary preheater and a secondary preheater connected in sequence. The inlet of the primary preheater is connected to the wastewater filter, and the outlet of the secondary preheater is connected to the first mass transfer intensification unit for preheating the wastewater. The inlet of the secondary preheater is connected to the outlet of the wet oxidation reactor, and the outlet of the primary preheater is connected to the deep oxidation tower. The tail gas processor is connected to the top of the deep oxidation tower. The ion exchange membrane electrolyzer is connected to the circulation pipeline. By setting up the wastewater filter, preheating unit, tail gas processor and ion electrolyzer, a complete treatment process is provided for the whole system. Solid impurities are removed through the wastewater filter, temperature exchange is achieved through the preheating unit, energy is saved and the environment is protected, the discharged gas is purified through the tail gas processor, and the treatment efficiency is further improved through the ion exchange membrane electrolyzer, not only improving the removal rate of pollutants, but also ensuring the environmental friendliness and sustainability of the system. In addition, the present invention also provides a method for treating high-phenol wastewater, using the above treatment system to treat high-phenol wastewater. Preferably, the method for treating high-phenol wastewater includes the following steps: the high-phenol wastewater is heat-exchanged and then undergoes a wet oxidation reaction. After the reaction, the wastewater is cooled, and the oxidation liquid is subjected to deep oxidation treatment and then enters the subsequent reaction stage. Preferably, the reaction temperature during the wet oxidation reaction is 220 - 250 °C, and the reaction pressure is 4 - 6 MPa. The treatment method of the present invention is simple to operate, the operating conditions are milder, and the product quality is higher. Compared with the prior art, the beneficial effects of the present invention are as follows: (1) By integrating the wet oxidation reactor and the deep oxidation tower, the present invention realizes continuous oxidation treatment, greatly enhancing the decomposition efficiency of organic substances, especially high-phenol compounds; preliminary oxidation is provided by the wet oxidation reactor, and the deep oxidation tower further enhances the oxidation effect to ensure the thorough treatment of refractory substances. (2) By arranging the intensification reactor inside the connecting pipeline, the present invention preliminarily breaks and disperses the materials entering the wet oxidation reactor. At the same time, the intensification reactor and the stirrer are used in combination to break and disperse the microbubbles coming out of the intensification reactor again in a timely manner, so that they are more evenly distributed inside the whole connecting pipeline. (3) The present invention uses the distribution plate in combination with the third intensification reactor to fully mix the mixed materials coming out of the third intensification reactor and control the gas flow direction. Description of the Drawings Upon reading the following detailed description of the preferred embodiments, various other advantages and benefits will become apparent to those of ordinary skill in the art. The accompanying drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to denote the same components. In the drawings: FIG. 1 is a schematic structural diagram of a treatment system for high-phenol wastewater provided in Embodiment 1 of the present invention; FIG. 2 is a partially enlarged view of a wet oxidation reactor provided in Embodiment 1 of the present invention; FIG. 3 is a schematic structural diagram of a stirrer provided in Embodiment 1 of the present invention; FIG. 4 is a schematic structural diagram of a first demisting tray provided in Embodiment 1 of the present invention. Wherein: 1 - wet oxidation reactor; 2 - first mass transfer intensification unit; 201 - first intensification reactor; 202 - second intensification reactor; 203 - connecting pipeline; 204 - stirrer; 2041 - stirring rod; 2042 - stirring wire; 3 - second mass transfer intensification unit; 301 - third intensification reactor; 302 - fourth intensification reactor; 303 - gas-liquid distribution assembly; 3031 - distribution tray; 3032 - support grid; 3033 - guide plate; 304 - aeration tray; 305 - first demisting tray; 3051 - support tray; 3052 - first layer of metal mesh; 3053 - second layer of metal mesh; 306 - second demisting tray; 307 - diffusion tray; 4 - wastewater storage tank; 5 - high-pressure gas pipeline; 6 - deep oxidation tower; 7 - third mass transfer intensification unit; 701 - fifth intensification reactor; 702 - sixth intensification reactor; 703 - high-pressure nozzle; 704 - first heat exchanger; 705 - Throttle valve; 8 - Circulation pipeline; 801 - Second heat exchanger; 802 - Circulation pump; 9 - Wastewater filter; 10 - Preheating unit; 1001 - Primary preheater; 1002 - Secondary preheater; 11 - Tail gas processor; 12 - Ion exchange membrane electrolyzer. Detailed implementation manners The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific implementation manners. However, those skilled in the art will understand that the following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not specified by the manufacturer can all be obtained as conventional products through commercial purchase. In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. In order to more clearly illustrate the technical solutions in the present invention, the following will be described in the form of specific embodiments. Embodiment 1 Referring to FIGS. 1-4, a treatment system for high-phenol wastewater provided by an embodiment of the present invention is shown. Among them, referring to FIGS. 1-2, the treatment system includes a wet oxidation reactor 1. Among them, a first mass transfer intensification unit 2 is arranged outside the wet oxidation reactor 1, a second mass transfer intensification unit 3 is arranged inside the wet oxidation reactor 1, the first mass transfer intensification unit 2 is connected to the second mass transfer intensification unit 3, and the second mass transfer intensification unit 3 is arranged in the middle and lower part of the wet oxidation reactor 1. Specifically, the first mass transfer intensification unit 2 includes a first intensification reactor 201 connected to a wastewater storage tank 4 and a second intensification reactor 202 connected to a high-pressure gas pipeline 5. The first intensification reactor 201 is arranged above the second intensification reactor 202, and a communication pipeline 203 is arranged between the first intensification reactor 201 and the second intensification reactor 202. In a specific embodiment, a stirrer 204 is arranged inside the communication pipeline 203, and the stirrer 204 is arranged at two ports of the communication pipeline 203. Referring to FIG. 3, the stirrer 204 in this embodiment is a spherical stirrer 204, which includes a stirring rod 2041 and a plurality of stirring wires 2042 arranged circumferentially around the stirring rod 2041. The distance between adjacent stirring wires 2042 is equal, and the stirring wires 2042 are all arranged in a curved shape. The second mass transfer intensification unit 3 of the present invention includes a third intensification reactor 301 arranged at the bottom end of the wet oxidation reactor 1. The third intensification reactor 301 is connected to the communication pipeline 203, and a gas-liquid distribution component 303 is arranged at the outlet of the third intensification reactor 301. Specifically, the gas-liquid distribution component 303 includes a distribution plate 3031 and a support grid 3032 located above the distribution plate 3031. A plurality of guide plates 3033 are connected to the lower surface of the support grid 3032, and the angle between the guide plates 3033 and the lower surface of the support grid 3032 is 60-90°. Specifically, according to the use requirements, the inclination angle of the guide plate 3033 is 60°, 65°, 70°, 75°, 80°, 85° or 90°. The second mass transfer intensification unit 3 of the present invention further includes a fourth intensification reactor 302 arranged at the middle position of the wet oxidation reactor 1. The fourth intensification reactor 302 is connected to the high-pressure gas pipeline 5, and an aeration disc 304 is arranged below the outlet of the fourth intensification reactor 302. In a specific embodiment, a first demisting disc 305, a diffusion disc 307 and a second demisting disc 306 are sequentially arranged from bottom to top above the second mass transfer intensification unit 3. Specifically, referring to FIG. 4, the first demisting disc 305 includes a support disc 3051, a first layer of metal mesh 3052 and a second layer of metal mesh from bottom to top 3053. The reason why the demister tray of the present invention adopts the structural design of superimposing the support tray 3051 and the metal mesh is that the first layer of metal mesh 3052 and the second layer of metal mesh 3053 can provide a multi-level capture effect, so that the large bubbles in the air flow passing through the demister tray are effectively intercepted. At the same time, the first layer of metal mesh 3052 is a large-hole metal mesh, and the second layer of metal mesh 3053 is a small-hole metal mesh. The first layer of metal mesh 3052 captures larger bubbles, and the second layer of metal mesh 3053 captures smaller bubbles. Specifically, the pore diameter of the small-hole metal mesh is greater than 1 mm. Continuing to refer to Figure 1, the third mass transfer intensification unit 7 in the present invention includes a fifth intensification reactor 701 provided at the bottom end of the deep oxidation tower 6 and a sixth intensification reactor 702 provided above the fifth intensification reactor 701; the sixth intensification reactor 702 is connected to the gas-liquid mixture coming out of the top end of the wet oxidation reactor 1; the fifth intensification reactor 701 is connected to the ozone storage tank; specifically, the outlets of the fifth intensification reactor 701 and the sixth intensification reactor 702 are arranged oppositely, and at the same time, the fifth intensification reactor 701 and the sixth intensification reactor 702 are arranged on the same straight line, and high-pressure nozzles 703 are respectively connected to the outlets of the fifth intensification reactor 701 and the sixth intensification reactor 702. Preferably, a first heat exchanger 704 and a throttle valve 705 are provided on the connecting pipeline connecting the fifth intensification reactor 701 and the top end of the wet oxidation reactor 1. In the present invention, the throttle valve 705 is used as a component for further cooling and pressure reduction, which can not only convert the higher pressure energy of the high-pressure gas-liquid two-phase flow into cold energy, but also further cool the oxidation liquid to reach the temperature of deep oxidation. A circulation pipeline 8 is arranged outside the deep oxidation tower 6. The inlet of the circulation pipeline 8 is connected to the water outlet at the middle position of the deep oxidation tower 6, and a second heat exchanger 801 and a circulation pump 802 are arranged on the circulation pipeline 8. The high-phenol wastewater treatment system of the present invention further includes a wastewater filter 9, a preheating unit 10, a tail gas processor 11 and an ion-exchange membrane electrolyzer 12; wherein the wastewater filter 9 is connected to the preheating unit 10 and is connected to the wet oxidation reactor 1; the preheating unit 10 includes a primary preheater 1001 and a secondary preheater 1002 connected in sequence. The inlet of the primary preheater 1001 is connected to the wastewater filter 9, and the outlet of the secondary preheater 1002 is connected to the first mass transfer intensification unit 2 for preheating the wastewater; the inlet of the secondary preheater 1002 is connected to the outlet of the wet oxidation reactor 1, and the outlet of the primary preheater 1001 is connected to the deep oxidation tower 6 connected; the tail gas processor 11 is connected to the top end of the deep oxidation tower 6; the ion-exchange membrane electrolyzer 12 is connected to the circulation pipeline 8. When the high-phenol wastewater treatment system of the present invention is actually applied, it includes the following technological process: After the high-phenol wastewater is filtered by the wastewater filter 9 to remove solid impurities and phenolic condensation macromolecular solid impurities, it is sent to the preheating unit 10. The high-temperature and high-pressure gas-liquid two-phase flow coming out from the top of the wet oxidation reactor 1 exchanges heat with the low-temperature and high-pressure wastewater in the preheating unit 10, fully recovering the waste heat of the wastewater reaction and preheating the wastewater at the same time. The preheated wastewater and high-pressure gas are respectively introduced into the first mass transfer intensification unit 2. After being preliminarily broken and dispersed by the first mass transfer intensification unit 2, they enter the third intensification reactor 301 in the wet oxidation reactor 1 for secondary breaking and dispersion. In the wet oxidation reactor 1, monomolecular paracetamol and most phenolic substances in the wastewater are converted into carbon dioxide and small-molecule biodegradable substances; the converted wastewater comes out from the top of the wet oxidation reactor 1, then enters the preheating unit 10 for heat exchange, and then enters the deep oxidation tower 6 through a throttle valve for further oxidation. The treated oxidation liquid is sent to the ion membrane electrolyzer 12 for the preparation of sodium hydroxide and chlorine, and the tail gas coming out from the top of the deep oxidation tower 6 enters the tail gas processor 11 for purification and then is discharged. Example 2 The difference between this example and Example 1 is only that the included angle between the guide plate and the lower surface of the support grid is 30°. Example 3 The difference between this example and Example 1 is only that the fifth intensification reactor and the sixth intensification reactor are arranged in a staggered manner. Example 4 The difference between this example and Example 1 is only that the stirrer in the connecting pipe is arranged on the side wall. Comparative Example 1 The difference between this example and Example 1 is only that the first mass transfer intensification unit is not provided. Comparative Example 2 The difference between this example and Example 1 is only that the second mass transfer intensification unit is not provided. Comparative Example 3 The difference between this example and Example 1 is only that the third mass transfer intensification unit is not provided. Comparative Example 4 In this example, the prior art is adopted, and the high-phenol wastewater is directly introduced into the wet oxidation reactor for decontamination treatment. Experimental Example 1 The high-phenol wastewater of a certain chemical plant is treated by using the treatment systems of Examples 1-4 and Comparative Examples 1-3 respectively. The initial pollution indexes in the wastewater are measured as follows: phenol content 350 mg / L, COD content 500 mg / L, BOD content 200 mg / L. The treated wastewater is detected, and the obtained parameters are as follows: Table 1 Experimental Results When treating high-phenol wastewater with the prior art, the phenol content in the treated wastewater is 101.5 mg / L, the COD content is 120 mg / L, and the BOD content is 56 mg / L. As can be seen from Table 1, compared with the existing wet oxidation reactor, in the high-phenol wastewater treated by the treatment systems of the embodiments of the present invention, the phenol content is significantly reduced, and the COD content is also significantly reduced. That is to say, the phenol removal rate and COD removal rate in the embodiments of the present invention are significantly higher than those of the prior art; moreover, the phenol content, COD content and BOD content in Example 1 are even more significantly reduced, and the COD removal rate is above 99%. As can be seen from Table 1, Example 1 of the present invention is the optimal example. In this example, the mass transfer intensification units are respectively arranged inside and outside the wet oxidation reactor, and a mass transfer intensification unit is arranged in the deep oxidation tower. Through the cooperation of each component, the sewage treatment effect of the obtained treatment system is significantly better than that of the treatment system in the prior art; at the same time, the phenol content, COD content and BOD content are significantly lower than those of the phenol content, COD content and BOD content of each of its examples and comparative examples, indicating that the mass transfer intensification unit of Example 1 is cooperatively arranged with the entire treatment system, and the optimal treatment effect can be achieved. It can be seen that the treatment system of this example has a good treatment effect. Among them, the phenol removal rate and COD removal rate of Comparative Example 1 are lower than those of Example 1, because the first mass transfer intensification unit is not arranged in Comparative Example 1, and it cannot break and disperse the wastewater into micron-sized bubbles before the wastewater enters the wet oxidation reactor. Therefore, the wastewater and the high-pressure gas cannot react fully, and the treatment effect of Example 1 of the present invention cannot be achieved. It can be seen that Example 1 of the present invention is designed by setting a mass transfer intensification unit outside the wet oxidation reactor, which improves the treatment effect of the wastewater. In summary, compared with the prior art, the treatment system for high-phenol wastewater of the present invention has higher phenol removal rate, COD removal rate and BOD removal rate, and is worthy of wide promotion and application. The present invention also provides a method for treating high-phenol wastewater, including the following steps: heat-exchanging the high-phenol wastewater and then performing a wet oxidation reaction, cooling the reacted wastewater, and then performing deep oxidation treatment with an oxidation liquid and entering a subsequent reaction stage. Among them, the reaction temperature during the wet oxidation reaction is 220-250 °C, and the reaction pressure is 4-6 MPa. Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A treatment system for high-phenol wastewater, characterized in that, It includes a wet oxidation reactor and a deep oxidation tower; A first mass transfer intensification unit is arranged outside the wet oxidation reactor, a second mass transfer intensification unit is arranged inside the wet oxidation reactor, the first mass transfer intensification unit is connected with the second mass transfer intensification unit, and the second mass transfer intensification unit is arranged in the middle and lower part of the wet oxidation reactor; The bottom end of the deep oxidation tower is connected with the top end of the wet oxidation reactor, and a third mass transfer intensification unit is arranged inside the deep oxidation tower.

2. The treatment system for high-phenol wastewater according to claim 1, wherein The first mass transfer intensification unit includes a first intensification reactor connected with a wastewater storage tank and a second intensification reactor connected with a high-pressure gas pipeline. The first intensification reactor is arranged above the second intensification reactor, and a communication pipeline is arranged between the first intensification reactor and the second intensification reactor; Preferably, a stirrer is arranged inside the communication pipeline, and the stirrer is arranged at two ports of the communication pipeline.

3. The treatment system for high-phenol wastewater according to claim 2, characterized in that, The second mass transfer intensification unit includes a third intensification reactor arranged at the bottom end of the wet oxidation reactor. The third intensification reactor is connected with the communication pipeline, and a gas-liquid distribution component is arranged at the outlet of the third intensification reactor; Preferably, the gas-liquid distribution component includes a distribution plate and a support grid located above the distribution plate. A plurality of guide plates are connected to the lower surface of the support grid, and the angle between the guide plate and the lower surface of the support grid is 60-90°.

4. The treatment system for high-phenol wastewater according to claim 3, wherein The second mass transfer intensification unit further includes a fourth intensification reactor arranged at the middle position of the wet oxidation reactor. The fourth intensification reactor is connected with the high-pressure gas pipeline, and an aeration disc is arranged below the outlet of the fourth intensification reactor.

5. The treatment system for high-phenol wastewater according to claim 1, wherein, A first demisting disc, a diffusion disc and a second demisting disc are sequentially arranged from bottom to top above the second mass transfer intensification unit; the first demisting disc includes a support disc, a first layer of metal mesh and a second layer of metal mesh from bottom to top.

6. The treatment system for high-phenol wastewater according to claim 1, characterized in that, The third mass transfer intensification unit includes a fifth intensification reactor arranged at the bottom end of the deep oxidation tower and a sixth intensification reactor arranged above the fifth intensification reactor; the sixth intensification reactor is connected with the gas-liquid mixture coming out of the top end of the wet oxidation reactor; the fifth intensification reactor is connected with an ozone storage tank; Preferably, the outlets of the fifth intensification reactor and the sixth intensification reactor are arranged oppositely, and high-pressure nozzles are respectively connected to the outlets of the fifth intensification reactor and the sixth intensification reactor; Preferably, a first heat exchanger and a throttle valve are arranged on the connection pipeline connecting the fifth intensification reactor and the top end of the wet oxidation reactor.

7. The treatment system for high-phenol wastewater according to claim 6, characterized in that, A circulation pipeline is arranged outside the deep oxidation tower. The inlet of the circulation pipeline is connected with the water outlet at the middle position of the deep oxidation tower, and the outlet of the circulation pipeline is connected with the sixth intensification reactor; Preferably, a second heat exchanger and a circulation pump are arranged on the circulation pipeline.

8. The treatment system for high-phenol wastewater according to claim 7, wherein It also includes a wastewater filter, a preheating unit, a tail gas processor, and an ion exchange membrane electrolyzer; The wastewater filter is connected with the preheating unit and is connected with the wet oxidation reactor; The preheating unit includes a primary preheater and a secondary preheater connected in sequence. The inlet of the primary preheater is connected to the wastewater filter, and the outlet of the secondary preheater is connected to the first mass transfer intensification unit for preheating the wastewater. The inlet of the secondary preheater is connected to the outlet of the wet oxidation reactor, and the outlet of the primary preheater is connected to the deep oxidation tower. The tail gas processor is connected to the top of the deep oxidation tower. The ion exchange membrane electrolyzer is connected to the circulation pipeline.

9. A method for treating high-phenol wastewater by using the treatment system for high-phenol wastewater according to any one of claims 1-8, characterized in that, It includes the following steps: The high-phenol wastewater is heat-exchanged and then undergoes a wet oxidation reaction. After the reaction, the wastewater is cooled, and the oxidation liquid is subjected to deep oxidation treatment and then enters the subsequent reaction stage.

10. The treatment method of high-phenol wastewater according to claim 9, characterized in that, The reaction temperature during the wet oxidation reaction is 220 - 250 °C, and the reaction pressure is 4 - 6 MPa.

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