Reactor, ozone catalytic oxidation system and wastewater treatment method

Abstract

The application provides a reactor, an ozone catalytic oxidation system and a wastewater treatment method. A partition plate is arranged in a reaction chamber of the reactor, one end of the partition plate is arranged on an inner wall of the reaction chamber, the other end extends to an inner side in a horizontal direction of the reaction chamber and extends to an upper side of the reaction chamber, and the other end is arranged in a spaced manner with a top wall of the reaction chamber, so that the partition plate divides the reaction chamber into a fluidized bed area provided with fluidized bed materials and a fixed bed area provided with fixed bed materials, a water inlet of the reaction chamber is arranged at a lower part of the fluidized bed area, and a water outlet of the reaction chamber is arranged at a lower part of the fixed bed area. According to the application, the reaction efficiency of a reaction system containing solid, liquid and gas states can be improved.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, and more specifically, to a reactor, an ozone catalytic oxidation system, and a wastewater treatment method. Background Technology

[0002] In recent years, with the application of advanced oxidation technologies in highly toxic and recalcitrant organic wastewater, hydroxyl radicals generated during the reaction oxidize toxic organic pollutants, such as large, recalcitrant organic molecules, into low-toxicity or non-toxic small molecules, or even completely oxidize them into CO2, H2O, and small-molecule carboxylic acids, thereby achieving effective treatment of this type of wastewater. Currently commonly used advanced oxidation technologies include ozone catalytic oxidation, catalytic wet oxidation, catalytic hydrogen peroxide oxidation, electrocatalytic oxidation, and Fenton oxidation. These technologies generally have the advantages of strong oxidation capacity and fast wastewater degradation rate, but they also have the problems of high investment and operating costs.

[0003] To effectively address this issue, current approaches primarily focus on improving the reaction mass transfer efficiency of advanced oxidation technologies, enhancing the catalytic effect of catalysts, optimizing reactor structure and processing materials, and increasing the utilization efficiency of oxidants and the generation efficiency of hydroxyl radicals to reduce investment and operating costs. Ozone catalytic oxidation technology, characterized by its safety and lack of secondary pollution, is currently one of the most widely used and effective advanced oxidation technologies.

[0004] However, ozone catalytic oxidation technology is a three-phase contact reaction involving gas, water, and solid phases. The reactor's form, height, and internal structure are among the main factors affecting the efficiency of the ozone catalytic oxidation reaction. Currently, ozone catalytic oxidation reactors are mostly in the form of packed towers, spray towers, bubble towers, and plate towers. During application, problems such as blockage and caking often occur within the tower, increasing equipment maintenance and repair costs and hindering cost savings. Furthermore, in practical applications, increasing the reactor height is often used to increase the residence time of ozone in the system, thereby increasing the conversion efficiency of hydroxyl radicals and improving ozone reaction efficiency, aiming to reduce operating costs. However, excessively tall reactors are not suitable for on-site applications or exceed the site's capacity, while also increasing pump pressure and equipment energy consumption. On the other hand, increasing the reactor height has limited effect on improving ozone oxidation efficiency and also increases ozone consumption. The high production cost of ozone is also one of the reasons for the high investment and operating costs of ozone catalytic oxidation technology.

[0005] Therefore, it is hoped that the structure of the ozone catalytic oxidation process and its reactor can be further optimized to solve the problem of high investment and operating costs in the application of ozone catalytic oxidation technology. Summary of the Invention

[0006] To solve one or more of the above problems existing in the prior art, the present invention provides a reactor, an ozone catalytic oxidation system, and a wastewater treatment method.

[0007] The reactor of the present invention includes a reaction chamber, in which a partition is provided. One end of the partition is disposed on the inner wall of the reaction chamber, and the other end extends inward in the horizontal direction of the reaction chamber and extends upward. The other end is spaced from the top wall of the reaction chamber, so that the partition divides the reaction chamber into a fluidized bed area provided with fluidized bed materials and a fixed bed area provided with fixed bed materials. The water inlet of the reaction chamber is disposed at the lower part of the fluidized bed area, and the water outlet of the reaction chamber is disposed at the lower part of the fixed bed area.

[0008] Wherein, the partition may include: a first partition, one end of which is disposed on the bottom wall or side wall of the reaction chamber, and the other end extends inward in the horizontal direction of the reaction chamber; and a second partition, one end of which is connected to the other end of the first partition, and the other end extends upward.

[0009] Wherein, the fluidized bed area may be in an inverted funnel shape or generally in a "convex" shape.

[0010] Wherein, the water inlet may be disposed at the bottom of the reaction chamber, and an aeration device may be provided at the water inlet.

[0011] Wherein, the partition may be a sieve plate provided with air inlet holes.

[0012] Wherein, the partition may further include a third partition, one end of which is connected to the other end of the second partition, and the other end extends upward and extends outward of the fixed bed area.

[0013] Wherein, the reactor may further include a baffle chamber disposed outside the reaction chamber, and the liquid discharged from the water outlet of the reaction chamber enters the baffle chamber.

[0014] A plurality of baffle plates arranged in a staggered manner may be provided on the inner side wall of the baffle chamber, and the liquid entering the baffle chamber is discharged from the water outlet of the baffle chamber via the baffle plates.

[0015] Wherein, the particle size of the fluidized bed materials may be 0.1 - 100 mm, the specific surface area of the fluidized bed materials may be more than 100 m2 / g, and the strength of the fluidized bed materials may be greater than 120 N; the particle size of the fixed bed materials may be 10 - 100 mm, the specific surface area of the fixed bed materials may be more than 300 m2 / g, and the strength of the fixed bed materials may be greater than 100 N.

[0016] The present invention also provides an ozone catalytic oxidation system, comprising: the reactor described above; a water supply unit connected to the inlet of the reaction chamber for supplying the liquid to be treated to the reaction chamber; and an ozone generator connected to the inlet of the reaction chamber for supplying ozone to the reaction chamber.

[0017] The ozone catalytic oxidation system may also include a gas-water mixer, with the water supply unit and ozone generator connected to the water inlet of the reaction chamber via the gas-water mixer.

[0018] The ozone catalytic oxidation system may also include a dosing unit, the outlet of which is connected to a gas-water mixer to provide an oxidant to the gas-water mixer. The oxidant is one or more of hydrogen peroxide, calcium peroxide, sodium hypochlorite, calcium hypochlorite, chlorine dioxide, and persulfate.

[0019] The present invention also provides a wastewater treatment method, which uses the above-mentioned reactor for wastewater treatment, wherein the fluidized bed material is a fluidized bed catalyst and the fixed bed material is a fixed bed catalyst. The wastewater treatment method includes the following steps: step (a): allowing ozone-containing wastewater to enter the fluidized bed region for a first-stage ozone catalytic oxidation reaction; and step (b): allowing the wastewater after the first-stage ozone catalytic oxidation reaction to be returned to the fixed bed region for a second-stage ozone catalytic oxidation reaction.

[0020] In step (a), the reaction time of the wastewater in the fluidized bed area can be controlled to be within 20 minutes.

[0021] The process may include step (c) after step (b), in which the wastewater after the second-stage ozone catalytic oxidation reaction is deflected so that the residual ozone in the wastewater can undergo an oxidation reaction.

[0022] According to the present invention, the reaction efficiency of reaction systems involving solid, liquid, and gas states can be improved. In particular, it can solve the problems of low mass transfer efficiency, poor ozone catalytic oxidation effect, unreasonable reactor design, and high investment and operating costs existing in ozone catalytic oxidation technology. Attached Figure Description

[0023] Figure 1 An example of the arrangement of baffles in the reaction chamber of the reactor of the present invention is shown schematically.

[0024] Figure 2 This is a schematic diagram of the reactor in Embodiment 1 of the present invention.

[0025] Figure 3 This is a schematic diagram of the reactor in Embodiment 2 of the present invention.

[0026] Figure 4 This is a top view of the first partition of the reactor in Embodiment 2 of the present invention.

[0027] Figure 5 This is a top view of the reactor in Embodiment 2 of the present invention.

[0028] Figure 6 This is a schematic diagram of the ozone catalytic oxidation system of Embodiment 3 of the present invention.

[0029] Symbol Explanation

[0030] 1. Ozone catalytic oxidation system

[0031] 10 reactors

[0032] 100 reaction chambers

[0033] 110 partition

[0034] 111 First partition

[0035] 112 Second partition

[0036] 113 Third partition

[0037] 120 fluidized bed region

[0038] 121 Fluidized Bed Material

[0039] 122 Inlet

[0040] 130 Fixed Bed Area

[0041] 131 Fixed Bed Materials

[0042] 132 outlet

[0043] 140 Aeration Device

[0044] 150 exhaust outlet

[0045] 160 material filling port

[0046] 170 Breathing Valve Mounting Port

[0047] 180 discharge port

[0048] 200 baffle chamber

[0049] 210 baffle plate

[0050] 220 Baffle Chamber Outlet

[0051] 300 exhaust gas concentration detector

[0052] 400 exhaust gas destroyer

[0053] 20 Water Supply Department

[0054] 30 Liquid Flow Meter

[0055] 40 Dosing Department

[0056] 50 dosing pump

[0057] 60 Liquid Flow Meter

[0058] 70 Ozone Generator

[0059] 80 gas flow meter

[0060] 90 air-water mixer Detailed Implementation

[0061] This invention provides a reactor capable of improving the reaction efficiency of a reaction system comprising solid, liquid, and gas phases. Specifically, the reactor, through a specific structural arrangement, allows a gas-water mixture to react in a fluidized bed region containing fluidized bed material and then be recirculated into a fixed bed region containing fixed bed material. Specifically, the reactor chamber is divided into a fluidized bed region and a fixed bed region by a partition. One end of the partition is located on the inner wall of the reaction chamber, and the other end extends horizontally inward and upward into the reaction chamber, separated from the top wall of the reaction chamber. Thus, the fluidized bed region and the fixed bed region are connected above the other end of the partition. Furthermore, a portion of the fluidized bed region is located below the partition, the inlet of the reaction chamber is located in the fluidized bed region, and the outlet of the reaction chamber is located in the lower part of the fixed bed region.

[0062] It should be noted that, in this specification, a fluidized bed refers to a bed formed by uniformly packing solid particles in a container with an open bottom. When fluid flows through at high speed from top to bottom, the movement of the solid particles causes the bed to expand. As the flow velocity increases further, the particles separate from each other and move within the fluid. The higher the flow velocity, the more vigorous the movement, and the particles move in all directions within the bed. This state is called solid fluidization, and the bed of solid particles after fluidization is called a fluidized bed. Additionally, in devices conducting multiphase processes, if a solid phase is involved and is in a static state, the solid particle material layer within that device is called a fixed bed.

[0063] Furthermore, in this specification, "extending in a certain direction" includes both extending along that direction and extending at an angle towards that direction. Additionally, in this specification, descriptions of orientation such as "up," "down," "vertical," and "horizontal" refer to the relative orientation of the device during actual use.

[0064] The following, combined with Figure 1 The specific arrangement of the baffles in the reaction chamber of the reactor of the present invention will be described.

[0065] Figure 1 An example of the arrangement of baffles within the reaction chamber of the reactor of the present invention is shown schematically. It should be noted that... Figure 1In order to more clearly show how the partition is set up, other components in the reaction chamber are omitted.

[0066] like Figure 1 As shown in (A), one end of the partition 110 in the reaction chamber 100 of the present invention is disposed on the bottom wall of the reaction chamber 100, and the other end extends inward in the horizontal direction of the reaction chamber 100 and upward in the reaction chamber 100. That is, the other end of the partition 110 extends obliquely upward. Thus, the lower part of the reaction chamber 100 is divided into a fluidized bed region 120 and a fixed bed region 130. The fluidized bed region 120 and the fixed bed region 130 communicate above the other end of the partition 110. Of course, one end of the partition 110 in the reaction chamber 100 of the present invention may also be disposed on the side wall of the reaction chamber 100.

[0067] Figure 1 (B) shows another example of a partition 110 within reaction chamber 100. Figure 1 As shown in (B), the partition 110 includes a first partition 111 and a second partition 112. One end of the first partition 111 is disposed on the side wall of the reaction chamber 100, and the other end of the first partition 111 extends inward along the horizontal direction of the reaction chamber 100. One end of the second partition 112 is connected to the other end of the first partition 111, and the other end of the second partition 112 extends upward along the vertical direction of the reaction chamber 100. That is, the first partition 111 and the side wall of the reaction chamber 100, and the second partition 112 and the first partition 11, are both at right angles. Thus, the lower part of the reaction chamber 100 is divided into a fluidized bed region 120 and a fixed bed region 130. The fluidized bed region 120 and the fixed bed region 130 communicate above the other end of the second partition 112.

[0068] Figure 1 (C) shows another example of a partition 110 within reaction chamber 100. (See diagram for example.) Figure 1 As shown in (C), one end of the first partition 111 is disposed on the side wall of the reaction chamber 100, and the other end of the first partition 111 extends upward at an inward angle in the horizontal direction of the reaction chamber 100. One end of the second partition 112 is connected to the other end of the first partition 111, and the other end of the second partition 112 extends upward along the vertical direction of the reaction chamber 100. Of course, one end of the partition 110 in the reaction chamber 100 of the present invention can also be disposed on the bottom wall of the reaction chamber 100.

[0069] Figure 1 (D) shows another example of a partition 110 within reaction chamber 100. This example is related to... Figure 1The difference in example (C) is that partition 110 further includes a third partition 113, one end of which is connected to the other end of the second partition 112, and the other end of the third partition 113 extends obliquely upward toward the outside of the fixed bed region 130. In this invention, it is preferred that... Figure 1 The third baffle 113 is arranged as in (D) to prevent the fluidized bed material 121 from flowing into the fixed bed region 130 from above during the reaction. Of course, one end of the baffle 110 in the reaction chamber 100 of the present invention can also be arranged on the bottom wall of the reaction chamber 100.

[0070] With the above configuration, the gas-water mixture entering the reaction chamber 100 undergoes the first stage reaction in the fluidized bed region 120 containing the fluidized bed material, and then flows upward back into the fixed bed region 130 containing the fixed bed material for the second stage reaction. Furthermore, because the gas-water mixture reacting in the fluidized bed region 120 experiences resistance from the baffle 110 above during its ascent, the residence time of the reacting gas within the fluidized bed region 120 is increased, thereby enhancing the reaction effect in the fluidized bed region 120. This improves the overall system reaction efficiency.

[0071] It should be noted that the arrangement and number of partitions 110 in the reaction chamber 100 of the present invention are not limited to the four methods described above. As long as the gas-water mixture is able to be resisted by the partitions 110 above it during its ascent in the fluidized bed region 120, and flows back into the fixed bed region 130 from the area above the partitions where the fluidized bed region 120 and the fixed bed region 130 communicate, various modifications can be made as needed. For example, the partitions 110 can be arranged in a ring along the side wall of the reaction chamber 100, so that the fixed bed region 130 surrounds the fluidized bed region 120 in a ring. Alternatively, partitions 110 can be arranged on opposite side walls of the reaction chamber 100, so that the fixed bed region 130 is convex in shape.

[0072] It should be noted that although the following uses ozone catalytic oxidation technology as an example, and combines specific embodiments 1 and 2 to illustrate the present invention, the reaction chamber 100 of the present invention is not limited to ozone catalytic oxidation technology, but can also be applied to reaction systems involving solid, liquid, and gas states, such as ozone-hydrogen peroxide technology, ozone-activated carbon technology, ozone-ultraviolet technology, electrocatalytic oxidation technology, supercritical water oxidation technology, and wet catalytic oxidation technology. For example, when applied to ozone-activated carbon technology, both the fluidized bed material and the fixed bed material are activated carbon.

[0073] Example 1

[0074] Figure 2 This is a schematic diagram of reactor 10 according to Embodiment 2 of the present invention. Figure 2As shown, the reactor 10 of this embodiment includes a reaction chamber 100, which is divided by a partition into a fluidized bed region 120 containing fluidized bed material 121 and a fixed bed region 130 containing fixed bed material 131. In this embodiment, the fluidized bed material 121 is a fluidized bed catalyst, and the fixed bed material 131 is a fixed bed catalyst. The partition in the reaction chamber 100 is composed of a first partition 111, a second partition 112, and a third partition 113. One end of the first partition 111 is disposed on the side wall of the reaction chamber 100, and the other end of the first partition 111 extends obliquely upward toward the inward side of the horizontal direction of the reaction chamber 100. One end of the second partition 112 is connected to the other end of the first partition 111, and the other end of the second partition 112 extends upward along the vertical direction of the reaction chamber 100. One end of the third partition 113 is connected to the other end of the second partition 112, and the other end of the third partition 113 extends upward at an angle toward the outside of the fixed bed region 130. Furthermore, the other end of the third partition 113 is spaced apart from the top wall of the reaction chamber 100. Moreover, the fluidized bed region 120 is partially located below the first partition 111, and the fixed bed region 130 is located on the other side of the entire partition.

[0075] like Figure 2 As shown, in this embodiment, the baffles are arranged on opposite sides of the reaction chamber 100, making the fluidized bed region 120 convex in shape. This causes the gas-water mixture to experience greater resistance from the baffles during its ascent, increasing the residence time of ozone in the fluidized bed region 120 and enhancing the oxidation effect within the fluidized bed region 120.

[0076] It should be noted that the inlet 122 of the reaction chamber 100 of the present invention is located in the lower part of the fluidized bed region 120, and the outlet 132 of the reaction chamber 100 is located in the lower part of the fixed bed region 130. However, in this embodiment, as... Figure 2 As shown, the outlet 132 of the preferred reaction chamber 100 is located as close as possible to the bottom of the fixed bed area 130, so that the gas-water mixture can fully contact the fixed bed material 131 to react before being discharged.

[0077] In addition, the inlet 122 of the preferred reaction chamber 100 is located at the bottom of the reaction chamber 100, and an aeration device 140 is installed at the inlet 122. The aeration device 140 may adopt jet aeration and / or microporous aeration.

[0078] Jet aeration is an aeration method that uses a jet aerator to mix gas and liquid inside a pipe and introduce them into the reaction device. When the liquid enters the nozzle of the jet aerator at high speed, the high-speed flowing liquid passes through the gas chamber, creating a local vacuum at the suction pipe. Under the action of vacuum negative pressure, the gas is drawn in and broken into a large number of tiny bubbles by the high-speed water flow. The resulting gas-water mixture enters the reactor through the diffuser.

[0079] In addition, microporous aeration has become the most common aeration method in practical applications due to its simple installation and operation and variety. Its principle is to cut and release the compressed air generated by the blower through the microporous structure of small holes, membranes or porous materials, thereby generating small bubbles. Generally, the bubble diameter generated by microporous aeration devices is less than 5 mm, which is much smaller than the bubble diameter generated by traditional aeration methods.

[0080] Therefore, in practical applications, the appropriate option can be selected based on the needs.

[0081] By setting up an aeration device 140, the gas-water mixture entering from the inlet 122 is secondary distributed through the aeration device 140 before reacting in the fluidized bed region 120. This allows the gas-water mixture, after secondary distribution through the aeration device 140, to propel the fluidized bed material 121, which acts as a fluidized bed catalyst, into a state of intense agitation within the reaction chamber 100 in the fluidized bed region 120, thus carrying out the first fluidized bed ozone catalytic oxidation reaction. After the reaction is completed in the fluidized bed region 120, the wastewater overflows from the connecting space above the baffle into the fixed bed region 130.

[0082] It should be noted that the components of the fluidized bed material 121 and the fixed bed material 131 of the present invention are not particularly limited and can be selected as needed. In this embodiment, when the reactor 10 is used in ozone catalytic oxidation technology, the particle size of the fluidized bed material 121, which serves as the fluidized bed catalyst, is preferably 0.1-100 mm, the specific surface area is preferably 100 m² / g or more, and the strength is preferably greater than 120 N. Similarly, the particle size of the fixed bed material 131, which serves as the fixed bed catalyst, is preferably 10-100 mm, the specific surface area is preferably 300 m² / g or more, and the strength is preferably greater than 100 N. By ensuring that the fluidized bed catalyst and the fixed bed catalyst meet the above conditions, the catalytic efficiency of ozone oxidation can be further improved.

[0083] Example 2

[0084] Figure 3 This is a schematic diagram of reactor 10 according to Embodiment 2 of the present invention. Additionally, Figure 4 This is a top view of the arrangement of the first partition 111 in the reactor 10 of Embodiment 2 of the present invention. Figure 5 This is a top view of reactor 10 according to Embodiment 2 of the present invention.

[0085] like Figures 3-5 As shown, the reactor 10 of this embodiment differs from the reactor 10 of Embodiment 1 in that the reactor 10 of this embodiment further includes a baffle chamber 200 disposed outside the reaction chamber 100. Liquid discharged from the outlet 132 enters the baffle chamber 200. A plurality of baffle plates 210 are arranged in a staggered manner on the inner side wall of the baffle chamber 200, and the liquid entering the baffle chamber 200 is discharged from the outlet 220 of the baffle chamber through the baffle plates 210.

[0086] This design combines reflux and baffle flow in the gas-water mixture, increasing ozone residence time and oxidation efficiency. Simultaneously, it reduces the height of reactor 10, thus lowering equipment investment. Consequently, reactor 10 has a compact and rational design, reducing equipment investment, operation, and maintenance costs.

[0087] In addition, such as Figure 4 As shown, the first partition 111 in this embodiment is a sieve plate with air inlet holes. The sieve plate can be a stainless steel plate with through holes. Normally, in a gas-liquid-solid three-phase system, this sieve plate allows gas and wastewater to pass through. However, in the reactor 10 structure of this invention, due to the presence of resistance, wastewater does not pass through the sieve plate in large quantities; instead, the gas in the gas-water mixture preferentially passes through the sieve plate. As a result, a portion of the ozone gas will pass through the sieve plate for secondary gas distribution and participate in the fixed-bed ozone catalytic oxidation reaction process, which is beneficial to improving ozone utilization and catalytic oxidation reaction efficiency.

[0088] Thus, the gas-water mixture entering from the inlet 122 undergoes secondary distribution via the aeration device 140 before reacting within the fluidized bed region 120. This secondary distribution via the aeration device 140 causes the gas-water mixture to violently agitate the fluidized bed material 121 (acting as a fluidized bed catalyst) within the reaction chamber 100, resulting in the first fluidized bed ozone catalytic oxidation reaction. After the reaction in the fluidized bed region 120, the gas-water mixture overflows into the fixed bed region 130. Simultaneously, some ozone gas passes through the first partition 111 (acting as a sieve plate) and enters the fixed bed material 131 (acting as a fixed bed catalyst) for the second fixed bed ozone catalytic oxidation reaction. After the reaction, the liquid flows out through the outlet 132 and enters the baffle chamber 200 from the reflux region. The liquid then undergoes oxidation by residual ozone and hydroxyl radicals via multiple baffles 210 before finally being discharged from the baffle chamber outlet 220.

[0089] In addition, such as Figure 3 and Figure 5As shown, a material loading port 160 and a discharge port 180 are provided at the top of the reaction chamber 100. The positions of the material loading port 160 and the discharge port 180 can be correspondingly arranged to the fluidized bed region 120 and the fixed bed region 130 to facilitate the filling of the fluidized bed region 120 and the fixed bed region 130 with the corresponding materials. In this embodiment, three material loading ports 160 and three discharge ports 180 are provided corresponding to the fluidized bed region 120 and the fixed bed region 130. In addition, a breather valve installation port 170 is provided at the top of the baffle chamber 200 for installing a breather valve. This breather valve is used to maintain the air pressure balance in the baffle chamber 200. In addition, a tail gas outlet 150 is provided between the reaction chamber 100 and the baffle chamber 200, and the tail gas can be collected and discharged through the tail gas outlet 150. However, the present invention is not limited thereto, and the positions and quantities of the material loading port 160, the unloading port 180, the breather valve installation port 170 and the exhaust gas outlet 150 can be set as needed.

[0090] Example 3

[0091] Figure 6 This is a schematic diagram of the ozone catalytic oxidation system 1 of Embodiment 3 of the present invention. The ozone catalytic oxidation system 1 of this embodiment is equipped with the reactor 10 of Embodiment 2.

[0092] like Figure 6 As shown, the ozone catalytic oxidation system 1 includes a reactor 10, a water supply unit 20 connected to the inlet 122 of the reactor 10, and an ozone generator 70. Preferably, the ozone catalytic oxidation system 1 includes a gas-water mixer 90 connected to the inlet 122 of the reactor 10. The water supply unit 20 and the ozone generator 70 are connected to the inlet 122 of the reaction chamber 100 via the gas-water mixer 90. That is, the outlet of the ozone generator 70 is connected to the inlet of the gas-water mixer 90, and the outlet of the water supply unit 20 is connected to the inlet of the gas-water mixer 90. Thus, the liquid to be treated discharged from the water supply unit 20 and the ozone gas generated from the ozone generator 70 are thoroughly mixed after entering the gas-water mixer 90 to form a gas-water mixture, which is then introduced into the reactor 10 to carry out the reaction as described in Example 2 above. Additionally, the preferred ozone catalytic oxidation system 1 may further include a dosing unit 40, the outlet of which is connected to a gas-water mixer 90 to provide an oxidant to the gas-water mixer 90. This oxidant may be one or more of hydrogen peroxide, calcium peroxide, sodium hypochlorite, calcium hypochlorite, chlorine dioxide, and persulfate. In this embodiment, the water supply unit 20 is an inlet pump, and the dosing unit 40 is a dosing tank.

[0093] In addition, such as Figure 6As shown, preferably, a liquid flow meter 30 is connected between the water supply unit 20 and the gas-water mixer 90, a dosing pump 50 and a liquid flow meter 60 are connected between the dosing unit 40 and the gas-water mixer 90, and a gas flow meter 80 is connected between the ozone generator 70 and the gas-water mixer 90. The liquid or gas delivery volume is controlled by each pump, and the liquid or gas delivery volume is monitored by each flow meter.

[0094] In addition, the preferred reactor 10 is also equipped with an exhaust gas concentration detector 300 and an exhaust gas destructor 400 connected to the exhaust gas concentration detector 300. In this embodiment, the exhaust gas concentration detector 300 is an ozone concentration detector. The ozone exhaust gas can be collected at the exhaust gas outlet 150 and then decomposed into oxygen by the exhaust gas concentration detector 300 and the exhaust gas destructor 400 before being discharged into the atmosphere.

[0095] In summary, the main working principle of this embodiment is as follows: the oxidant drawn by the dosing pump 50 from the dosing section 40 and the wastewater to be treated provided by the water supply section 20 enter the gas-water mixer 90 together. In addition, the ozone generated by the ozone generator 70 flows through the gas flow meter 80 and enters the gas-water mixer 90. The gas-water mixer 90 fully mixes the ozone and the wastewater to be treated. The mixed gas-water mixture is then distributed secondary through the aeration device 140 from the inlet 122 and enters the fluidized bed region 120. The gas-water mixture propels the fluidized bed material 121, which serves as a fluidized bed catalyst, into a state of intense agitation within the fluidized bed region 120, undergoing the first fluidized bed ozone catalytic oxidation reaction. After the reaction is completed in the fluidized bed region 120, the gas-water mixture flows back to the fixed bed region 130 from the area connecting the upper fluidized bed region 120 and the fixed bed region 130. Simultaneously, some ozone gas passes through the first partition 111, which acts as a sieve, and enters the fixed bed material 131, which serves as a fixed bed catalyst, for the second fixed bed ozone catalytic oxidation reaction. After the reaction is completed, the liquid flows out through the liquid outlet 132 and enters the baffle chamber 200 from the reflux area. The liquid undergoes an oxidation reaction of residual ozone and hydroxyl radicals through the baffle plate 210, and finally flows out from the baffle chamber outlet 220.

[0096] In addition, the present invention also provides a wastewater treatment method, comprising step (a): allowing ozone-containing wastewater to enter a fluidized bed region 120 provided with a fluidized bed catalyst to carry out a first-stage ozone catalytic oxidation reaction; and step (b): allowing the wastewater after the first-stage ozone catalytic oxidation reaction to be returned to a fixed bed region 130 provided with a fixed bed catalyst to carry out a second-stage ozone catalytic oxidation reaction.

[0097] Preferably, in step (a), the reaction time of wastewater in the fluidized bed region 120 is controlled to be within 20 minutes. This is because the reaction pathway design combining fluidized bed catalysts and fixed bed catalysts maximizes the variation of the ozone catalytic oxidation reaction efficiency curve. For the ozone reaction, 0-20 minutes is the period with the fastest ozone catalytic oxidation reaction rate. Therefore, using a fluidized bed catalyst with high catalytic activity can increase the probability of contact with ozone, improve the reaction rate, and increase the generation efficiency of hydroxyl radicals, thereby improving the ozone reaction efficiency. When the ozone catalytic reaction time exceeds 20 minutes, the reaction rate decreases significantly, and the pollutant concentration decreases. Using a fixed bed catalyst with a larger specific surface area can adsorb pollutants on the catalyst surface, increase the residence time of pollutants in the system, and enhance the ozone catalytic oxidation effect. The reaction pathway design of a front-end fluidized bed and a rear-end fixed bed can improve the ozone utilization rate of the ozone catalytic oxidation technology, increase the oxidation efficiency, and reduce operating costs.

[0098] Furthermore, it is preferable to include step (c) after step (b), in which the wastewater after the second-stage ozone catalytic oxidation reaction is deflected so that the residual ozone in the wastewater can undergo an oxidation reaction.

[0099] This is because by using reflux and deflection methods, the ozone catalytic oxidation reaction can be enhanced, the ozone catalytic oxidation reaction pathway can be enlarged, and the ozone utilization rate and catalytic oxidation reaction efficiency can be improved.

[0100] Effect detection

[0101] The ozone catalytic oxidation system 1 of Example 3 was used to treat a papermaking wastewater. COD was measured according to the "Determination of Chemical Oxygen Demand in Water - Dichromate Method" (HJ 828-2017), and color was measured according to the "Determination of Color in Water - Dilution Factor Method" issued by the Ministry of Ecology and Environment. Details are as follows:

[0102] Detection Example 1:

[0103] The fluidized bed catalyst was selected with a particle size of 20 mm, a specific surface area ≥150 m² / g, and a strength >120 N; the fixed bed catalyst was selected with a particle size of 50 mm, a specific surface area ≥310 m² / g, and a strength >110 N. The residence time of the ozone-containing wastewater in the reaction chamber was set to 1 hour.

[0104] The test results showed that the influent COD was 294.6 mg / L and the color was 320 times higher than normal. The treated effluent COD was 28.4 mg / L and the color was 5 times higher than normal. The COD removal rate was 90.35% and the color removal rate was 98.4%.

[0105] Detection Example 2:

[0106] The fluidized bed catalyst was selected with a particle size of 35 mm, a specific surface area ≥120 m² / g, and a strength >125 N; the fixed bed catalyst was selected with a particle size of 80 mm, a specific surface area ≥300 m² / g, and a strength >110 N. The residence time of the ozone-containing wastewater in the reaction chamber was set to 1 hour.

[0107] The test results showed that the influent COD was 259.4 mg / L and the color was 280 times higher than normal. The treated effluent COD was 40.3 mg / L and the color was 10 times higher than normal. The COD removal rate was 84.4% and the color removal rate was 96.4%.

[0108] Therefore, the device provided by the present invention can efficiently treat wastewater through catalytic treatment.

[0109] In summary, the present invention has the following technical effects:

[0110] This invention improves the reaction efficiency of reaction systems involving solid, liquid, and gas phases. Specifically, in ozone catalytic oxidation for wastewater treatment, the combination of fluidized and fixed-bed reactors enhances ozone utilization, catalyzes the generation of more hydroxyl radicals, increases ozone oxidation efficiency, and reduces operating costs. Furthermore, the reactor design incorporates a combination of reflux and baffle flow to increase ozone residence time and oxidation efficiency, while simultaneously reducing reactor height and investment. The compact and efficient reactor design lowers investment, operating, and maintenance costs. Specifically:

[0111] (1) The reaction path design combining fluidized bed and fixed bed can maximize the change of the oxidation efficiency curve of ozone catalytic oxidation reaction. The ozone reaction is fastest from 0 to 20 min. Using a fluidized bed catalyst with high catalytic activity can increase the contact probability with ozone, increase the reaction rate, and increase the generation efficiency of hydroxyl radicals, thereby improving the ozone reaction efficiency. When the ozone catalytic reaction time is greater than 20 min, the reaction rate decreases significantly and the pollutant concentration decreases. Using a fixed bed catalyst with a large specific surface area can adsorb pollutants on the catalyst surface, increase the residence time of pollutants in the system, and enhance the ozone catalytic oxidation effect. The reaction path design of fluidized bed in the front and fixed bed in the back can improve the ozone utilization rate of ozone catalytic oxidation technology, improve oxidation efficiency, and reduce operating costs.

[0112] (2) The fluidized bed region adopts a roughly convex or inverted funnel design, which will cause the gas-water mixture to be subject to greater resistance during the upward process, which will increase the residence time of ozone gas in the fluidized bed region and enhance the ozone catalytic oxidation effect of the fluidized bed. In addition, under the action of this resistance, some ozone gas will pass through the sieve plate for secondary gas distribution and participate in the fixed bed ozone catalytic oxidation reaction process. The convex or inverted funnel design optimizes the structure of the traditional ozone catalytic reactor, which is conducive to improving the ozone utilization rate and the reaction efficiency of catalytic oxidation.

[0113] (3) The fixed bed catalyst loading area is the reflux zone of the reactor, and the baffle plate installation area is the baffle zone of the reactor. The optimization of the reactor structure of reflux and baffle can respectively enhance the ozone catalytic oxidation reaction, increase the ozone catalytic oxidation reaction path, and improve the ozone utilization rate and catalytic oxidation reaction efficiency.

[0114] Although the present invention has been described above in conjunction with the above embodiments, the present invention is not limited to the described embodiments. Various modifications and variations can be made without departing from the scope of the present invention.

Claims

1. An ozone catalytic oxidation system (1) characterized by, The reactor (10) comprises a reaction chamber (100) in which a partition plate (110) is arranged, one end of the partition plate (110) is arranged on the inner wall of the reaction chamber (100), the other end of the partition plate (110) extends to the inner side in the horizontal direction of the reaction chamber (100) and extends upwardly, and the other end is arranged spaced apart from the top wall of the reaction chamber (100), so that the partition plate (110) divides the reaction chamber (100) into a fluidized bed region (120) provided with fluidized bed materials (121) and a fixed bed region (130) provided with fixed bed materials (131), the water inlet (122) of the reaction chamber (100) is arranged at the lower part of the fluidized bed region (120), the water outlet (132) of the reaction chamber (100) is arranged at the lower part of the fixed bed region (130), and the partition plate (110) is a sieve plate provided with gas inlet holes. A water supply part (20) connected to the water inlet (122) of the reaction chamber (100) for providing the treated liquid to the reaction chamber (100); and An ozone generator (70) connected to the water inlet (122) of the reaction chamber (100) for providing ozone to the reaction chamber (100). The partition plate (110) comprises:

2. The ozone catalytic oxidation system (1) according to claim 1, characterized in that, A first partition plate (111) arranged at one end on the bottom wall or side wall of the reaction chamber (100) and extending to the inner side in the horizontal direction of the reaction chamber (100) at the other end; and A second partition plate (112) connected at one end to the other end of the first partition plate (111) and extending upwardly at the other end. The fluidized bed region (120) is in the shape of an inverted funnel or generally in the shape of a "convex" character.

3. The ozone catalytic oxidation system (1) according to claim 1, characterized in that, The water inlet (122) is arranged at the bottom of the reaction chamber (100), and an aeration device (140) is arranged at the water inlet (122).

4. The ozone catalytic oxidation system (1) according to claim 1, characterized in that, The partition plate (110) further comprises a third partition plate (113) connected at one end to the other end of the second partition plate (112) and extending upwardly at the other end of the third partition plate (113) and extending outwardly to the fixed bed region (130).

5. The ozone catalytic oxidation system (1) according to claim 2, characterized in that, The reactor (10) further comprises a baffle chamber (200) arranged outside the reaction chamber (100), the liquid discharged from the water outlet (132) of the reaction chamber (100) enters the baffle chamber (200), a plurality of baffle plates (210) are arranged on the inner side of the side wall of the baffle chamber (200) in a staggered manner, and the liquid entering the baffle chamber (200) is discharged from the baffle chamber water outlet (220) via the baffle plates (210).

6. The catalytic ozone oxidation system (1) according to any one of claims 1 to 5, characterized in that ​ 7. The ozone catalytic oxidation system (1) as claimed in claim 1, characterized in that, The fluidized bed material (121) has a particle size of 0.1-100 mm, a specific surface area of 100 m2 / g or more, and a strength of more than 120 N; and the fixed bed material (131) has a particle size of 10-100 mm, a specific surface area of 300 m2 / g or more, and a strength of more than 100 N.

8. The ozone catalytic oxidation system (1) according to claim 1, characterized in that, The ozone catalytic oxidation system (1) further comprises a gas-water mixer (90), and the water supply part (20) and the ozone generator (70) are connected to the water inlet (122) of the reaction chamber (100) via the gas-water mixer (90).

9. The ozone catalytic oxidation system (1) according to claim 8, characterized in that, The ozone catalytic oxidation system (1) further comprises a dosing part (40), and the discharge port of the dosing part (40) is connected to the gas-water mixer (90) to provide an oxidant to the gas-water mixer (90), wherein the oxidant is one or more of hydrogen peroxide, calcium peroxide, sodium hypochlorite, calcium hypochlorite, chlorine dioxide, and persulfate.

10. A method of treating wastewater, characterized by, A wastewater treatment method using the ozone catalytic oxidation system (1) according to any one of claims 1-9, wherein the fluidized bed material (121) is a fluidized bed catalyst, and the fixed bed material (131) is a fixed bed catalyst, The wastewater treatment method comprises the following steps: Step (a): making the wastewater containing ozone enter the fluidized bed area (120) to perform a first-stage ozone catalytic oxidation reaction; and Step (b): making the wastewater after the first-stage ozone catalytic oxidation reaction backflow into the fixed bed area (130) to perform a second-stage ozone catalytic oxidation reaction.

11. The wastewater treatment method according to claim 10, characterized by, In the step (a), the reaction time of the wastewater in the fluidized bed area (120) is controlled to be within 20 minutes.

12. The wastewater treatment method according to claim 10 or 11, characterized by, After the step (b), a step (c) is further included, in which the wastewater after the second-stage ozone catalytic oxidation reaction is bended to make the residual ozone in the wastewater perform an oxidation reaction.

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