Magnetic separation and catalytic ozonation integrated equipment

Abstract

The invention provides magnetic separation and catalytic ozonation integrated equipment, which belongs to the technical field of water pollution control and treatment and comprises the processes of magnetic catalyst preparation, catalytic ozonation reaction, magnetic catalyst recovery and the like. A magnetic recovery plate arranged in the equipment is connected with a solenoid and a power switch, in the ozone catalytic oxidation reaction process, the power switch is switched off, a magnetic catalyst is uniformly dispersed in the equipment, and the ozone catalytic oxidation reaction is carried out; after the reaction is finished, the power switch is closed, and the magnetic recovery plate generates electromagnetism to capture the magnetic catalyst, so that the magnetic catalyst is effectively separated from the coking wastewater. When the device is used for treating the coking wastewater, the catalytic ozonation efficiency can be improved, and the magnetic catalyst can be effectively separated and recycled. The device is applied to homogeneous ozone catalytic oxidation treatment of coking wastewater, is efficient, small in occupied area and high in resource recycling rate, and has a better application prospect on chemical sewage with complex components, high organic matter content and poor biodegradability.

Description

Technical Field

[0001] The present invention relates to the technical field of water pollution control and treatment, and in particular to a magnetic separation ozone catalytic oxidation integrated device. Background Art

[0002] Ozone catalytic oxidation is often used for deep treatment of coking wastewater due to its thorough degradation and simple operation to ensure compliance with emission standards and subsequent zero-emission treatment. Catalysts in the ozone catalytic oxidation process are divided into two categories: homogeneous and heterogeneous. Homogeneous catalysts are simple to prepare, have high removal efficiency, and fast reaction speed. In existing studies, they have shown better removal effects than heterogeneous catalysts. However, after the reaction of homogeneous catalysts, metal ions dissolve in water, which is not only difficult to recover, but may also cause secondary pollution of metal ions, limiting the practical application of this technology.

[0003] The commonly used magnetic material recovery equipment on the market needs to be equipped with conveyor belts, material collection buckets, etc., with complex structures, large floor space and high production costs. In addition, the magnetic material recovery technology applied to the ozone catalytic oxidation reaction device cannot guarantee the air tightness of the device, which can easily lead to ozone gas leakage, greatly reducing the removal effect and increasing the equipment operation cost.

[0004] In response to this technical problem, a magnetic separation ozone catalytic oxidation integrated equipment is proposed. The prepared magnetic homogeneous catalyst improves the ozone catalytic oxidation reaction rate in the ozone reactor. After the reaction is completed, the built-in magnetic recovery plate can quickly separate and recover the magnetic catalyst from the coking wastewater according to the magnetic separation technology. The equipment only needs to build a magnetic recovery plate in the ozone catalytic oxidation reactor, connect the solenoid and the power switch, and does not need to be equipped with other complex accessories. It occupies a small area and has a good catalyst recovery effect. At the same time, it achieves the goal of strengthening ozone catalytic oxidation removal and improving the reusability of ozone catalysts. Summary of the invention

[0005] In order to overcome the technical difficulty of recycling existing homogeneous catalysts, the purpose of the present invention is to provide an integrated magnetic separation ozone catalytic oxidation equipment to improve the reusability and treatment efficiency of homogeneous ozone catalysts and ensure high-efficiency and low-cost treatment of coking wastewater and other types of wastewater by homogeneous ozone catalytic oxidation.

[0006] The present invention provides a magnetic separation ozone catalytic oxidation integrated equipment, characterized in that the integrated equipment comprises a magnetic catalyst preparation, an ozone catalytic oxidation reaction and a magnetic catalyst recovery process.

[0007] The present invention provides a magnetic separation ozone catalytic oxidation integrated device, characterized in that the magnetic catalyst (13) is prepared with Fe 3 O 4As the substrate, active metals (M = Cu, Mn, Ce, La, etc.) are loaded according to the mass ratio of Fe:M = 1:1~3. The specific operation steps are as follows: (1) Prepare a 1-2 mol / L solution A of metal nitrates such as Cu, Mn, Ce, and La using deionized water; (2) While stirring, Fe 3 O 4 The powder is added to solution A and mixed evenly to form solution B; (3) Use ultrasonic dispersion solution B, continue stirring and immersing for 24 to 36 hours; (4) Centrifuge solution B, discard the supernatant, and age the mixture in an oven at 100°C for 12 to 24 h. (5) Wash the mixture with deionized water 2 to 3 times until it becomes neutral, and dry it in an oven at 120 °C for 8 to 12 h; (6) The obtained product is placed in a muffle furnace and calcined at 700-900 °C for 3-5 h at a heating rate of 5-10 °C / min under nitrogen protection.

[0008] The present invention provides a magnetic separation ozone catalytic oxidation integrated device, characterized in that the ozone catalytic oxidation reaction process is as follows: coking wastewater is pumped in through a water inlet (11), the magnetic catalyst (13) is added to the ozone catalytic oxidation integrated device, and ozone is introduced through an ozone air inlet (12) to perform a catalytic oxidation reaction. The active metal in the magnetic catalyst (13) can promote ozone to produce hydroxyl free radicals with stronger oxidizing properties. At the same time, the active metal reacts with Fe 3 O 4 The Fe-Cu, Fe-Mn, Fe-Ce, and Fe-La high-efficiency bimetallic catalytic components are formed to accelerate the generation of hydroxyl radicals and greatly improve the efficiency of ozone catalytic oxidation treatment. After the ozone catalytic oxidation reaction and catalyst separation process are completed, the coking wastewater is discharged from the water outlet (14), and the ozone tail gas is passed into the tail gas collection and treatment device from the tail gas discharge port (15).

[0009] The present invention provides a magnetic separation ozone catalytic oxidation integrated device, characterized in that the ozone catalytic oxidation integrated device has a built-in magnetic recovery plate (1), the magnetic recovery plate (1) is connected to a solenoid (2), and the solenoid (2) is connected to a power switch (3). During the ozone catalytic oxidation reaction, the power switch (3) is disconnected at a fixed time, no current passes through the solenoid (2), the magnetic recovery plate (1) does not have electromagnetic properties, and the magnetic catalyst (13) is evenly dispersed under the promotion of ozone aeration to carry out ozone catalytic oxidation reaction; after the reaction is completed, the power switch (3) is closed at a fixed time, the solenoid (2) is energized, the magnetic recovery plate (1) generates electromagnetic properties, the powdered magnetic catalyst (13) is quickly captured by the magnetic recovery plate (1), the magnetic catalyst (13) is recovered, and solid-liquid separation is effectively achieved.

[0010] The present invention provides a magnetic separation ozone catalytic oxidation integrated device, characterized in that the magnetic separation ozone catalytic oxidation integrated device is equipped with a two-way breathing valve (16) for maintaining the air pressure balance in the device, and an observation port (17) for observing the operation of the device to facilitate maintenance.

[0011] Based on the above invention, the advantages of the integrated magnetic separation ozone catalytic oxidation equipment are:

[0012] 1. It overcomes the limitation of the complex structure of conventional magnetic separation equipment. It only controls the electromagnetic properties of the magnetic recovery plate through the power switch to achieve rapid separation of magnetic catalyst and coking wastewater. The equipment has a simple structure, small footprint, low cost and high separation efficiency.

[0013] 2. It avoids the ozone leakage problem caused by the application of magnetic separation technology in ozone catalytic oxidation reaction. The built-in magnetic recovery plate ensures the air tightness of the equipment, ensures the ozone concentration involved in ozone catalytic oxidation, and avoids ozone tail gas leakage.

[0014] 3. The introduction of magnetic catalysts promotes the ozone catalytic oxidation reaction of coking wastewater. The loaded active metals can form efficient bimetallic catalytic components with Fe, accelerate the generation of hydroxyl radicals, and improve the efficiency of ozone catalytic oxidation treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the device of the present invention.

[0016] Figure 2 Schematic diagram of the catalytic ozone oxidation reaction process.

[0017] Figure 3 Schematic diagram of the magnetic catalyst separation and recovery process.

[0018] Figure 4 This is the removal rate curve of phenol and water using magnetic catalyst.

[0019] Among them, there are a magnetic recovery plate (1), a solenoid (2), a power switch (3), a water inlet (11), an ozone inlet (12), a magnetic catalyst (13), a water outlet (14), an exhaust gas outlet (15), a two-way breathing valve (16), and an observation port (17). DETAILED DESCRIPTION

[0020] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0021] Example 1

[0022] Homogeneous catalysts were applied to the ozone catalytic oxidation treatment of the effluent from the secondary sedimentation tank of a coking wastewater plant. However, the difficulty in recycling the catalysts has limited the use of homogeneous catalysts. In addition, since the commonly used magnetic separation technology on the market often requires the use of conveyor belts or rollers to recover magnetic materials, it cannot be directly applied to treatment equipment that reacts in a closed environment such as ozone catalytic oxidation. Figure 1 As shown, the magnetic separation ozone catalytic oxidation integrated device proposed by the present invention has a built-in magnetic recovery plate (1), which has no direct gas exchange with the external environment, thereby ensuring the airtightness during the ozone catalytic oxidation reaction. The specific implementation method is as follows: the magnetic recovery plate (1) is welded to the inner wall of the magnetic separation ozone catalytic oxidation integrated device, and is connected to the solenoid (2) and the power switch (3) through a power cord. When the power switch (3) is closed, the power switch (3), the solenoid (2), and the magnetic recovery plate (1) form a closed loop, and each turn on the solenoid (2) will generate a magnetic field. According to the "Ampere's law", hold the energized solenoid with your right hand, with four fingers pointing in the direction of the current, and the end pointed by the thumb is the N pole of the energized solenoid (2). The magnetic field in the solenoid (2) just forms a closed magnetic field with the external magnetic field, so that the magnetic recovery plate (1) generates electromagnetic properties, which can capture the magnetic catalyst (13) and complete the separation and recovery of the magnetic catalyst (13); after the power switch (3) is turned off, the closed loop and the magnetic field disappear, the magnetic recovery plate (1) no longer has electromagnetic properties, and the magnetic catalyst (13) is evenly dispersed in the coking wastewater under the agitation of ozone aeration, participating in the ozone catalytic oxidation reaction.

[0023] Example 2

[0024] Applications such as Figure 1The magnetic separation ozone catalytic oxidation integrated equipment shown in the figure performs ozone catalytic oxidation treatment on the biochemical effluent of coking wastewater. The specific reaction process is as follows: before starting the reaction, the power switch (3) is disconnected at a fixed time, no current flows through the solenoid (2), and the magnetic recovery plate (1) does not have electromagnetic properties. It is the same as a common ozone catalytic oxidation reactor. The coking wastewater enters the magnetic separation ozone catalytic oxidation integrated equipment from the water inlet (11), and ozone is blown in from the ozone air inlet (12). Under the promotion of ozone aeration, the powdered magnetic catalyst (13) is evenly dispersed in the integrated equipment. The active metal loaded on the magnetic catalyst (13) forms a bimetallic active component with iron, catalyzing ozone to produce a large number of hydroxyl free radicals, which react with organic matter in the coking wastewater to reduce the COD concentration in the water (such as Figure 2 as shown).

[0025] After the ozone catalytic oxidation reaction is completed, the magnetic catalyst (13) is separated and recovered. The specific process is as follows: the power switch (3) is closed at a fixed time, and current flows through the solenoid (2). According to the right-hand screw rule, the energized solenoid generates a magnetic field pointing in the direction of the right thumb. The magnetic recovery plate (1) therefore has electromagnetic properties. The powdered magnetic catalyst (13) is captured by the magnetic field and quickly fixed to the magnetic recovery plate (1) under the action of the magnetic field force, completing the solid-liquid separation process of the magnetic catalyst (13) and the coking wastewater. At this time, the water outlet (14) is opened to discharge the treated coking wastewater that does not contain the magnetic catalyst (13), completing the first cycle operation of the coking wastewater (such as Figure 3 as shown).

[0026] Before the second cycle, the power switch (3) is disconnected again, the magnetic recovery plate (1) does not have electromagnetic properties, the powdered magnetic catalyst (13) is evenly dispersed in the integrated device, and the ozone catalytic oxidation experiment is completed (such as Figure 2 As shown). Then the power switch (3) is closed again, the magnetic recovery plate (1) has electromagnetic properties, completes the separation and recovery of the magnetic catalyst (13), and completes the second cycle of ozone catalytic oxidation of coking wastewater after drainage (as shown). Figure 3 as shown).

[0027] During operation, the observation port (17) can be used to observe the operation status of the integrated magnetic separation ozone catalytic oxidation device. The two-way breathing valve (16) is used to balance the pressure difference between the inside and outside of the device. For example, when the coking wastewater is introduced into the device from the water inlet (11), a positive pressure difference is generated in the device, and the gas can be released outward through the two-way breathing valve (16); when the treated coking wastewater is discharged from the device from the water outlet (14), a negative pressure difference is generated in the device, and the gas can be blown inward through the two-way breathing valve (16); during the ozone catalytic oxidation process, the breathing valve is automatically closed, and the ozone in the tank does not leak out, thereby ensuring the ozone utilization rate.

[0028] Example 3

[0029] The catalytic efficiency of homogeneous catalysts is much higher than that of heterogeneous catalysts, but homogeneous catalysts are difficult to recycle, which limits their application in ozone catalytic oxidation reactions. The magnetic separation ozone catalytic oxidation integrated equipment is equipped with a magnetic recovery plate (1) on the basis of an ordinary ozone catalytic oxidation reactor, and uses electromagnetic principles and ozone aeration to achieve separation, recovery and uniform dispersion of the magnetic catalyst (13). The specific reaction process of the magnetic catalyst (13) in the magnetic separation ozone catalytic oxidation integrated equipment is as follows: Figure 2 As shown, the power switch (3) is turned off, and the magnetic catalyst (13) is evenly dispersed in the equipment under the agitation of ozone aeration, and is fully mixed with the secondary sedimentation effluent of the coking wastewater. The active metals loaded on the catalyst form bimetallic active components with Fe, such as Fe (III) / Fe (II) and Cu (II) / Cu (I) redox cycles can be formed between Fe and Cu, which promotes electron transfer between active metals and improves the efficiency of catalytic oxidation reactions.

[0030] like Figure 3 As shown, a reaction cycle ends, the power switch (3) is closed at a fixed time, and the Fe in the magnetic catalyst (13) 3 O 4 The components are adsorbed onto the magnetic recovery plate (1) under the action of electromagnetic force, the water outlet (14) is opened, the coking wastewater is discharged, and the magnetic catalyst (13) remains on the magnetic recovery plate (1), thus completing the separation and recovery of the magnetic catalyst.

[0031] Example 4

[0032] like Figure 4 As shown, the catalyst of the magnetic separation ozone catalytic oxidation integrated equipment was used to treat phenol water with an initial concentration of 50 mg / L. After 30 minutes of reaction, the removal rate of phenol was as high as 99% or more. The experiment was repeated 5 times, and the removal rate could still reach more than 94%. Ozone oxidation and the catalyst of the present invention were used to treat the biochemical-coagulation effluent of a coking plant. After 60 minutes of reaction, the COD removal rate of ozone oxidation was only about 19%. After adding the catalyst of the present invention, the COD removal rate of the biochemical-coagulation effluent of the coking wastewater could reach about 50%, and the removal rate was increased by 2.63 times. Considering the normal loss in practical applications, the recovery rate of the catalyst of the magnetic separation ozone catalytic oxidation integrated equipment can be as high as 95%~98%.

[0033] The typical embodiments of the present invention are described above, but the present invention is not limited to the use of the above-mentioned implementation cases, and various modifications or changes can be implemented within the scope of the claims. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The present invention provides a magnetic separation ozone catalytic oxidation integrated device, characterized in that: The integrated device comprises a magnetic catalyst preparation, an ozone catalytic oxidation reaction and a magnetic catalyst recovery process; the ozone catalytic oxidation integrated device has a built-in magnetic recovery plate (1), the magnetic recovery plate (1) is connected to a solenoid (2), and the solenoid (2) is connected to a power switch (3); during the ozone catalytic oxidation reaction, the power switch (3) is disconnected at a fixed time, no current passes through the solenoid (2), the magnetic recovery plate (1) has no electromagnetic properties, and the powdered magnetic catalyst (13) is evenly dispersed in the device under the promotion of ozone aeration to perform an ozone catalytic oxidation reaction; after the ozone catalytic oxidation reaction is completed, the power switch (3) is closed at a fixed time, the solenoid (2) is energized, the magnetic recovery plate (1) generates electromagnetic properties, the powdered magnetic catalyst (13) is captured by the magnetic recovery plate (1), the magnetic catalyst (13) is recovered, and solid-liquid separation is achieved.

2. The magnetic separation ozone catalytic oxidation integrated equipment according to claim 1 is characterized in that: The present invention provides a magnetic separation ozone catalytic oxidation integrated device, characterized in that the magnetic catalyst (13) is prepared with Fe3O4 as the substrate, and active metals (M=Cu, Mn, Ce, La, etc.) are loaded according to the mass ratio of Fe:M=1:1-3, and the specific operation steps are as follows: (1) Prepare a 1-2 mol / L solution A of metal nitrates such as Cu, Mn, Ce, and La using deionized water; (2) Add Fe3O4 powder to solution A while stirring, and mix well to form solution B; (3) Use ultrasonic dispersion solution B, continue stirring and immersing for 24 to 36 hours; (4) Centrifuge solution B, discard the supernatant, and age the mixture in an oven at 100°C for 12 to 24 h. (5) Wash the mixture with deionized water 2 to 3 times until it becomes neutral, and dry it in an oven at 120 °C for 8 to 12 h; (6) The obtained product is placed in a muffle furnace and calcined at 700-900 °C for 3-5 h at a heating rate of 5-10 °C / min under nitrogen protection.

3. The magnetic separation ozone catalytic oxidation integrated equipment according to claim 1 is characterized in that: The ozone catalytic oxidation reaction process is as follows: coking wastewater is pumped in from the water inlet (11), the magnetic catalyst (13) is added to the ozone catalytic oxidation integrated equipment, and ozone is introduced through the ozone air inlet (12) for catalytic oxidation reaction; the active metal in the magnetic catalyst (13) forms Fe-Cu, Fe-Mn, Fe-Ce, Fe-La high-efficiency bimetallic catalytic components with Fe3O4, and participates in the ozone catalytic oxidation reaction; after the ozone catalytic oxidation reaction is completed, the magnetic catalyst (13) is fixed by the magnetic recovery plate (1), the coking wastewater is discharged from the water outlet (14), and the ozone tail gas is introduced into the tail gas collection and treatment device from the tail gas discharge port (15), thereby completing the homogeneous ozone catalytic oxidation reaction of the coking wastewater.

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