Wastewater catalytic oxidation device and wastewater treatment system and method

Abstract

The invention provides a wastewater catalytic oxidation device and a wastewater treatment system and method. The device comprises a reaction tank, an ultraviolet lamp post, a protective sleeve and a plug flow stirrer, the number of the ultraviolet lamp poles is multiple, the multiple ultraviolet lamp poles are uniformly arranged in the reaction tank, and each ultraviolet lamp pole is vertically arranged in the reaction tank; the number of the protective sleeves is in one-to-one correspondence with the number of the ultraviolet lamp posts, and each protective sleeve covers the corresponding ultraviolet lamp post; the protective sleeve is in a net shape, and the protective sleeve is coated with a titanium dioxide coating; the plug flow stirrer is arranged in the reaction tank and is used for stirring wastewater in the reaction tank during operation. The device is simple in structure and convenient to use, and the biodegradability of the wastewater can be effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of wastewater treatment, and in particular to a wastewater catalytic oxidation device, a wastewater treatment system and a method. Background Art

[0002] Water environment protection has become a focal issue of universal concern in human society. With the rapid growth of the economy, high-concentration organic wastewater is becoming increasingly harmful to water resources. In particular, the following types of industrial wastewater, such as printing and dyeing wastewater, coal chemical wastewater, petrochemical wastewater, etc., have the following common characteristics: high pollutant concentration, contain a large amount of difficult-to-degrade organic matter, and poor biochemical treatment performance. At present, wastewater treatment technology can often only effectively treat a specific type of industrial wastewater. Faced with complex wastewaters such as printing and dyeing, coal chemical industry and petrochemical industry, due to their poor biodegradability, the use of biochemical treatment methods has poor results, making it impossible for the current wastewater treatment process to achieve the standard for wastewater discharge. In view of this, the present invention is proposed. Summary of the invention

[0003] The first purpose of the present invention is to provide a wastewater catalytic oxidation device, which can use ozone and hydroxyl radicals generated by ultraviolet light to decompose difficult-to-degrade organic matter in the wastewater, thereby helping to improve the biodegradability of the wastewater, reduce the concentration of pollutants, and make the treated wastewater meet the requirements of biochemical treatment, thereby reducing the difficulty of wastewater treatment.

[0004] The second object of the present invention is to provide a wastewater treatment system, which can sequentially utilize a wastewater catalytic oxidation device, a hydrolysis acidification unit, a biochemical treatment unit, and a contact oxidation unit to treat wastewater, and can effectively remove nutrients such as nitrogen and phosphorus in the wastewater, and reduce the content of organic matter in the wastewater, so that the wastewater can meet the requirements of emission standards.

[0005] The third object of the present invention is to provide a wastewater treatment method which is simple to operate and has high treatment efficiency. By using the above-mentioned wastewater treatment system to treat the wastewater, the wastewater can meet the requirements of emission standards.

[0006] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted: The present invention provides a wastewater catalytic oxidation device, which comprises: a reaction tank, an ultraviolet lamp column, a protective sleeve and a plug flow agitator; The number of the ultraviolet lamp posts is multiple, and the multiple ultraviolet lamp posts are evenly arranged in the reaction pool, and each of the ultraviolet lamp posts is vertically arranged in the reaction pool; The number of the protective covers corresponds to the number of the ultraviolet lamp poles, and each of the protective covers is disposed on the corresponding ultraviolet lamp pole; the protective covers are in a mesh shape, and are coated with a titanium dioxide coating; The plug flow agitator is arranged in the reaction tank to agitate the wastewater in the reaction tank during operation.

[0007] Exemplarily, the number of the plug flow agitators is two, and the two plug flow agitators are respectively arranged at two diagonals of the reaction tank along the diagonal line of the reaction tank.

[0008] Exemplarily, the distance between adjacent ultraviolet lamp poles is within a first distance range.

[0009] Exemplarily, the distance between the bottom of the ultraviolet lamp column and the bottom of the reaction pool is within a second distance range.

[0010] Exemplarily, the distance between the plug flow agitator and the ultraviolet lamp column is greater than or equal to a third distance.

[0011] The present invention also provides a wastewater treatment system, which comprises a wastewater catalytic oxidation unit, a hydrolysis acidification unit, a biochemical treatment unit and a contact oxidation unit connected in sequence; the wastewater is sequentially treated by the wastewater catalytic oxidation unit, the hydrolysis acidification unit, the biochemical treatment unit and the contact oxidation unit and then discharged; Wherein, the wastewater catalytic oxidation unit is the above-mentioned wastewater catalytic oxidation device.

[0012] Exemplarily, the wastewater treatment system further includes an open-air regulating tank; the wastewater treated by the wastewater catalytic oxidation unit is input into the hydrolysis acidification unit after being treated in the open-air regulating tank.

[0013] Exemplarily, the contact oxidation unit includes a contact oxidation tank and a chlorine dioxide generator; the chlorine dioxide generator is connected to the contact oxidation tank to input chlorine dioxide into the contact oxidation tank.

[0014] Exemplarily, the wastewater treatment system further includes a pretreatment unit; after the wastewater is treated by the pretreatment unit, it is input into the wastewater catalytic oxidation unit.

[0015] The present invention also provides a wastewater treatment method, which uses the wastewater treatment system described above to treat wastewater; the method comprises: The wastewater is treated by using the wastewater catalytic oxidation unit, the hydrolysis acidification unit, the biochemical treatment unit and the contact oxidation unit in sequence.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The above scheme of the present invention can cover all parts of the reaction pool with ultraviolet light by setting a plurality of ultraviolet lamp posts and evenly setting the plurality of ultraviolet lamp posts in the reaction pool, thereby increasing the contact area between ultraviolet light and wastewater, thereby improving the treatment efficiency and treatment effect of wastewater; by covering with a protective cover coated with a titanium dioxide coating, the efficiency of photochemical catalytic oxidation can be further improved, and the biodegradability of wastewater can be further improved; by setting a plug flow agitator to stir the wastewater, it can be ensured that the wastewater is fully mixed with hydroxyl radicals and ozone, thereby improving the treatment effect of difficult-to-degrade organic matter in the wastewater. In short, the device structure of this scheme is simple, easy to operate, and can effectively improve the biodegradability of wastewater. And the design of the wastewater catalytic oxidation device allows the direct use of the wastewater pool in the prior art as a reaction pool, that is, it can be transformed on the basis of the existing wastewater pool to form a device. This method helps to reduce the cost of wastewater treatment, and due to its good technical application potential, it has a broad prospect for promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings: Figure 1 A schematic diagram of a wastewater catalytic oxidation device provided in an embodiment of the present invention; Figure 2 A schematic diagram of a wastewater catalytic oxidation device provided in an embodiment of the present invention in a top view (with the fixing frame omitted); Figure 3 A schematic block diagram of a wastewater treatment system provided by one embodiment of the present invention; Figure 4 A schematic block diagram of a wastewater treatment system provided for a specific embodiment of the present invention.

[0018] In the figure: 10, wastewater catalytic oxidation unit; 11, reaction tank; 12, protective cover; 13, ultraviolet lamp column; 14, plug flow agitator; 15, fixed frame; 20, open-air regulating tank; 30, hydrolysis acidification unit; 31, hydrolysis acidification tank; 40, biochemical treatment unit; 41, anaerobic tank; 42, anoxic tank; 43, aerobic tank; 50, contact oxidation unit; 51, chlorine dioxide generator; 52, contact oxidation tank. DETAILED DESCRIPTION

[0019] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but those skilled in the art will understand that the embodiments described below are part of the embodiments of the present invention, rather than all of the embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] In order to more clearly explain the technical solution of the present invention, it is described in the form of specific embodiments below.

[0021] Example 1 like Figure 1 As shown, this embodiment provides a wastewater catalytic oxidation device, which includes: a reaction tank 11, an ultraviolet lamp column 13, a protective cover 12 and a plug flow agitator 14; there are multiple ultraviolet lamp columns 13, and the multiple ultraviolet lamp columns 13 are evenly arranged in the reaction tank 11 and each ultraviolet lamp column 13 is vertically arranged in the reaction tank 11; the number of protective covers 12 corresponds to the number of ultraviolet lamp columns 13, and each protective cover 12 is covered on the corresponding ultraviolet lamp column 13; the protective cover 12 is mesh-shaped, and the protective cover 12 is coated with a titanium dioxide coating; the plug flow agitator 14 is arranged in the reaction tank 11 to stir the wastewater in the reaction tank 11 during operation.

[0022] In such Figure 1 In the illustrated embodiment, a fixing frame 15 is provided above the liquid surface of the reaction pool 11. One end of the ultraviolet lamp post 13 away from the reaction pool 11 is fixed on the fixing frame 15. The material of the fixing frame 15 may be an aluminum alloy. The fixing frame 15 may be pre-set with mounting holes corresponding to the ultraviolet lamp posts 13 (the mounting holes may serve as lamp holders of the ultraviolet lamp posts 13) to facilitate the installation and fixation of the ultraviolet lamp posts 13. In some embodiments, the ultraviolet lamp posts 13 may be mounted on the fixing frame 15 by threaded connection.

[0023] The ultraviolet lamp pole 13 of this embodiment can be selected as needed, for example, an ultraviolet lamp pole with a power of 50-70 watts and an ultraviolet light wavelength of 10-200 nm can be selected.

[0024] In some embodiments, the device may further include a controller which is connected to the plurality of ultraviolet lamp poles 13 to control the operation of the ultraviolet lamp poles 13 .

[0025] In this embodiment, each ultraviolet lamp pole 13 is covered with a protective cover 12, and the protective cover 12 is in a mesh shape. In some embodiments, the main material of the protective cover 12 can be a steel cable coated with titanium dioxide, that is, the protective cover 12 is woven using the steel cable coated with titanium dioxide. The end of the protective cover 12 away from the reaction pool 11 can be fixed to the fixing frame 15 by threaded connection. This facilitates disassembly and replacement during subsequent use.

[0026] In this embodiment, when the device is working, ultraviolet light can be used to generate ozone and hydroxyl radicals under the action of titanium dioxide. Ozone and hydroxyl radicals have strong oxidizing properties and can oxidatively decompose the poorly biodegradable organic matter in the wastewater, so that part of the difficult-to-degrade organic matter in the wastewater can be directly decomposed into substances such as carbon dioxide and water, and part of it can be cracked into small molecular biodegradable organic matter for subsequent biological treatment and removal. This helps to improve the biodegradability of the wastewater.

[0027] The above scheme can cover all parts of the reaction pool 11 with ultraviolet light by setting a plurality of ultraviolet lamp posts 13 and evenly setting the plurality of ultraviolet lamp posts 13 in the reaction pool 11, thereby increasing the contact area between ultraviolet light and wastewater, thereby improving the treatment efficiency and treatment effect of wastewater; by covering a protective cover 12 coated with a titanium dioxide coating, the efficiency of photochemical catalytic oxidation can be further improved, and the biodegradability of wastewater can be further improved; by setting a plug flow agitator 14 to stir the wastewater, it can be ensured that the wastewater is fully mixed with hydroxyl radicals and ozone, thereby improving the treatment effect of difficult-to-degrade organic matter in the wastewater. In short, the device structure of the scheme is simple, the operation is convenient, and the biodegradability of wastewater can be effectively improved. And the design of the wastewater catalytic oxidation device allows the wastewater pool in the prior art to be directly used as a reaction pool, that is, it can be transformed on the basis of the existing wastewater pool to form a device. This method helps to reduce the cost of wastewater treatment, and due to its good technical application potential, it has a broad prospect for promotion.

[0028] Combined with reference Figure 1-2 (exist Figure 2, the fixing frame 15 is omitted), in this embodiment, the number of the plug flow agitator 14 is two, and the two plug flow agitators 14 are respectively arranged at the two diagonals of the reaction tank 11 along the diagonals of the reaction tank 11. By arranging the two plug flow agitators 14 diagonally, the flow field generated by the agitator can form a more uniform stirring effect in the reaction tank 11, which is conducive to the full mixing of the reactants and the catalyst, and improves the reaction efficiency. And the plug flow agitator 14 in the diagonal position can reduce the dead zone (the area not affected by the stirring) in the reaction tank 11, ensuring that the fluid in the entire tank can be effectively stirred. In short, using this setting method to stir the wastewater helps to further enhance the mixing degree of the wastewater with hydroxyl radicals and ozone, thereby further improving the wastewater treatment efficiency.

[0029] Exemplarily, the distance between adjacent ultraviolet lamp poles 13 is within a first distance range. The first distance range can be selected according to the power of the selected ultraviolet lamp pole 13. In a specific embodiment, the power of the ultraviolet lamp pole 13 is 50-70 watts, the diameter is 26 mm, and the first distance range can be [1m, 1.2m]. It can be understood that when the distance between adjacent ultraviolet lamp poles 13 is large, it may lead to lower concentrations of hydroxyl radicals and ozone, affecting the treatment effect of wastewater. When the distance between adjacent ultraviolet lamp poles 13 is small, it will cause a waste of energy. By limiting the distance between adjacent ultraviolet lamp poles 13, this example can reduce the cost of the device and the cost of wastewater treatment while ensuring the concentration of hydroxyl radicals and ozone.

[0030] Exemplarily, the distance between the bottom of the ultraviolet lamp post 13 and the bottom of the reaction tank 11 is within a second distance range. The second distance range can be selected according to the power of the ultraviolet lamp post 13. In some embodiments, the second distance range can be [0.8m, 1.2m]. When the ultraviolet lamp post 13 is too far from the bottom of the reaction tank 11, the concentrations of hydroxyl radicals and ozone at the bottom of the reaction tank 11 may be low, which will affect the treatment efficiency of the wastewater. When the ultraviolet lamp post 13 is too close to the bottom of the reaction tank 11, the surging of sediments in the stratum of the reaction tank 11 may damage the ultraviolet lamp post 13. The scheme of this example can ensure that the ultraviolet light emitted by the ultraviolet lamp post 13 covers all areas in the reaction tank 11, and can also avoid damage to the ultraviolet lamp post 13 caused by the surging of the bottom sediments by limiting the distance between the ultraviolet lamp post 13 and the bottom of the tank within the second distance range.

[0031] Exemplarily, the distance between the plug-flow agitator 14 and the ultraviolet lamp column 13 is greater than or equal to the third distance. The third distance can be selected according to the blade size and power of the plug-flow agitator 14. By limiting the distance between the plug-flow agitator 14 and the ultraviolet lamp column 13, the liquid flow generated by the plug-flow agitator 14 can be prevented from directly impacting the ultraviolet lamp column 13, thereby preventing the ultraviolet lamp column 13 from being damaged and improving the service life of the entire device.

[0032] The embodiment of the present invention also provides a wastewater treatment system. Figure 3-4 , the wastewater treatment system includes a wastewater catalytic oxidation unit 10, a hydrolysis acidification unit 30, a biochemical treatment unit 40 and a contact oxidation unit 50 connected in sequence; the wastewater is discharged after being treated by the wastewater catalytic oxidation unit 10, the hydrolysis acidification unit 30, the biochemical treatment unit 40 and the contact oxidation unit 50 in sequence; wherein the wastewater catalytic oxidation unit 10 is the wastewater catalytic oxidation device in the above embodiment. In this embodiment, the wastewater catalytic oxidation unit 10 can decompose the difficult-to-degrade organic matter in the wastewater, the hydrolysis acidification unit 30 can degrade the macromolecular organic matter in the wastewater, the biochemical treatment unit 40 can perform biochemical treatment on the wastewater to remove nitrogen, phosphorus and COD from the wastewater, and the contact oxidation unit 50 can fully oxidize the difficult-to-biodegrade organic matter that may remain in the wastewater, and can sterilize and disinfect the wastewater. In short, the wastewater treatment system can effectively remove pollutants in the wastewater and promote the discharge of wastewater in compliance with standards.

[0033] Alternatively, if Figure 4 As shown, the hydrolysis acidification unit 30 may include a hydrolysis acidification tank 31 .

[0034] Alternatively, if Figure 4 As shown, the biochemical treatment unit 40 may include an anaerobic tank 41, an anoxic tank 42 and an aerobic tank 43 connected in sequence.

[0035] In such Figure 3 , 4 In the embodiment shown, the wastewater treatment system further includes an open-air regulating tank 20; the wastewater treated by the wastewater catalytic oxidation unit 10 is input into the hydrolysis acidification unit 30 after being treated by the open-air regulating tank 20. It can be understood that the wastewater treated by the wastewater catalytic oxidation unit 10 contains a lot of ozone. In this embodiment, the open-air regulating tank 20 is used to reduce the ozone that may remain in the water body to prevent it from affecting the downstream biochemical system (i.e., the biochemical treatment unit 40) and preventing it from reducing the biological activity of the activated sludge.

[0036] Alternatively, if Figure 4 As shown, the contact oxidation unit 50 may include a contact oxidation tank 52 and a chlorine dioxide generator 51; the chlorine dioxide generator 51 is connected to the contact oxidation tank 52 to input chlorine dioxide into the contact oxidation tank 52. Chlorine dioxide can disinfect the water body and oxidize the residual organic matter that is difficult to biodegrade, which helps to promote the discharge of wastewater in compliance with the standards.

[0037] Optionally, the wastewater treatment system further includes a pretreatment unit; after the wastewater is treated by the pretreatment unit, it is input into the wastewater catalytic oxidation unit 10. The pretreatment unit includes but is not limited to a coarse and fine screen, a primary sedimentation tank, a regulating tank (to facilitate the distinction from the open-air regulating tank 20, the regulating tank is called a primary regulating tank), etc., which will not be described in detail. Treating the wastewater through the pretreatment unit can create good treatment conditions for the subsequent treatment units and improve the overall treatment effect.

[0038] Alternatively, if Figure 4 As shown, a secondary sedimentation tank is provided between the biochemical treatment unit 40 and the contact oxidation unit 50. After the wastewater treated by the biochemical treatment unit 40 passes through the secondary sedimentation tank to remove the sludge, it is input into the contact oxidation unit 50. The sludge in the secondary sedimentation tank can be input into the sludge dewatering room.

[0039] This embodiment also provides a wastewater treatment method, which uses the wastewater treatment system described above to treat wastewater; the method includes: sequentially using a wastewater catalytic oxidation unit 10, a hydrolysis acidification unit 30, a biochemical treatment unit 40 and a contact oxidation unit 50 to treat the wastewater.

[0040] In applications such as Figure 3 When the system shown is used for wastewater treatment, the method may specifically include the following steps: First, the wastewater is collected into the primary regulating tank to regulate the water quality and water quantity. Then, the wastewater in the regulating tank is input into the sedimentation tank by a lifting pump, and a flocculant (such as PAC) and a coagulant (such as PAM) are added to remove the sediment in the wastewater. Next, the precipitated wastewater is input into the intermediate water tank, and the wastewater is input into the reaction tank 11 by means of the lifting pump in the intermediate water tank, so that the wastewater is treated with ozone and hydroxyl radicals excited by ultraviolet light, so that the difficult-to-degrade organic matter is converted into easily biodegradable organic matter. After ultraviolet light catalytic oxidation treatment, the wastewater is input into the open-air regulating tank 20, and acid is added into the open-air regulating tank 20 to improve the decomposition efficiency of ozone and reduce the ozone content. The wastewater treated in the open-air regulating tank 20 is input into the hydrolysis acidification tank 31 through the lifting pump, so that the large molecular organic matter is removed by the hydrolysis acidification tank 31. The wastewater after hydrolysis and acidification is input into the anaerobic tank 41 through the lifting pump, and then passes through the anaerobic tank 41, the anoxic tank 42 and the aerobic tank 43 for biochemical treatment. The wastewater after biochemical treatment is input into the secondary sedimentation tank, and the sludge in the wastewater is separated by the secondary sedimentation tank (it can be recovered by the secondary sedimentation tank, or it can be discharged from the secondary sedimentation tank to the sludge dewatering room for treatment). The wastewater obtained after separation is input into the contact oxidation tank 52, and chlorine dioxide is used to disinfect the water body and oxidize the residual difficult-to-biodecompose organic matter. The treated wastewater can be discharged according to the discharge standard after passing the test.

[0041] Example 2 The only difference between this example and Example 1 is that the two plug flow agitators are located on the same side of the reaction tank.

[0042] Example 3 The only difference between this example and Example 1 is that no open-air regulating tank is provided. In this example, the wastewater treated by the wastewater catalytic oxidation unit is directly input into the hydrolysis acidification unit.

[0043] Comparative Example 1 The difference between this example and the first embodiment is that the protective cover is a closed protective cover, and the material of the protective cover is transparent plastic.

[0044] Comparative Example 2 The only difference between this example and Example 1 is that there is no coating on the protective cover.

[0045] Experimental example The wastewater treatment systems in Examples 1-3 and Comparative Examples 1-2 were used to treat wastewater (100 m / h of printing and dyeing wastewater), respectively. The water quality of the untreated wastewater is shown in Table 1.

[0046] Table 1 Wastewater quality

[0047] The water quality of the intermediate water after treatment by the wastewater catalytic oxidation unit is shown in Table 2.

[0048] Table 2 Intermediate water quality

[0049] The water quality of the final water obtained after treatment by the wastewater treatment system is shown in Table 3 below.

[0050] Table 3 Final water quality

[0051] It can be seen from Tables 1-2 that the wastewater catalytic oxidation device of the present invention can effectively improve the biodegradability of wastewater. Among them, the intermediate water treated by the device of Example 1 has the best biodegradability, which can reach 0.5. The biodegradability of the intermediate water treated in Example 2 is slightly lower than that in Example 1. This may be because the plug flow agitators in Example 2 are all set on the same side, and the stirring effect is poor, resulting in the distribution uniformity of ozone and hydroxyl radicals being lower than that in Example 1. The biodegradability of the intermediate water treated in Comparative Example 1 is slightly lower than that in Example 1. This may be because the fully enclosed protective cover has a blocking effect on ultraviolet light, large light resistance, and less ultraviolet light entering the wastewater, affecting the concentration of ozone and hydroxyl radicals. The biodegradability of the intermediate water treated in Comparative Example 2 is slightly lower than that in Example 1. This may be because Example 1 increases the concentration of ozone and hydroxyl radicals in the wastewater by using a titanium dioxide coating, thereby improving the biodegradability of the intermediate water.

[0052] As can be seen from Table 3, the wastewater treatment system of the present invention has a good wastewater treatment effect and can promote the discharge of wastewater in compliance with standards. Among them, the wastewater purification effect of Example 1 is the best. The COD, ammonia nitrogen and total phosphorus contents in Example 3 are significantly higher than those in Example 1. This may be because the ozone in the wastewater in Example 3 enters the biochemical treatment unit, inhibiting the biochemical treatment efficiency, so the effect of nitrogen removal, phosphorus removal and COD removal is poor.

[0053] In short, the present invention can effectively improve the biodegradability of wastewater and promote the discharge of wastewater in compliance with standards.

[0054] 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 it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wastewater catalytic oxidation device, characterized in that: include: Reaction pool, UV lamp column, protective cover and plug flow agitator; The number of the ultraviolet lamp posts is multiple, and the multiple ultraviolet lamp posts are evenly arranged in the reaction pool, and each of the ultraviolet lamp posts is vertically arranged in the reaction pool; The number of the protective covers corresponds to the number of the ultraviolet lamp posts, and each of the protective covers is covered on the corresponding ultraviolet lamp post; The protective cover is in a mesh shape and is coated with a titanium dioxide coating; The plug flow agitator is arranged in the reaction tank to agitate the wastewater in the reaction tank during operation.

2. The wastewater catalytic oxidation device according to claim 1, characterized in that: The number of the plug flow agitators is two, and the two plug flow agitators are respectively arranged at two diagonal corners of the reaction tank along the diagonal line of the reaction tank.

3. The wastewater catalytic oxidation device according to claim 1, characterized in that: The distance between adjacent ultraviolet lamp poles is within a first distance range.

4. The wastewater catalytic oxidation device according to claim 1, characterized in that: The distance between the bottom of the ultraviolet lamp column and the bottom of the reaction pool is within a second distance range.

5. The wastewater catalytic oxidation device according to any one of claims 1 to 4, characterized in that: The distance between the plug flow agitator and the ultraviolet lamp column is greater than or equal to a third distance.

6. A wastewater treatment system, characterized in that: It comprises a wastewater catalytic oxidation unit, a hydrolysis acidification unit, a biochemical treatment unit and a contact oxidation unit which are connected in sequence; the wastewater is discharged after being treated in sequence by the wastewater catalytic oxidation unit, the hydrolysis acidification unit, the biochemical treatment unit and the contact oxidation unit; Wherein, the wastewater catalytic oxidation unit is the wastewater catalytic oxidation device according to any one of claims 1-5.

7. The wastewater treatment system according to claim 6, characterized in that: It also includes an open-air regulating tank; the wastewater treated by the wastewater catalytic oxidation unit is input into the hydrolysis acidification unit after being treated in the open-air regulating tank.

8. The wastewater treatment system according to claim 6, wherein the contact oxidation unit comprises a contact oxidation tank and a chlorine dioxide generator; the chlorine dioxide generator is connected to the contact oxidation tank to input chlorine dioxide into the contact oxidation tank.

9. The wastewater treatment system according to any one of claims 6 to 8, characterized in that: It also includes a pretreatment unit; after the wastewater is treated by the pretreatment unit, it is input into the wastewater catalytic oxidation unit.

10. A method for treating wastewater, characterized in that: The wastewater treatment system according to any one of claims 6 to 9 is used to treat wastewater; the method comprising: The wastewater is treated by using the wastewater catalytic oxidation unit, the hydrolysis acidification unit, the biochemical treatment unit and the contact oxidation unit in sequence.

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