Electrocatalysis coupling catalytic ozonation reaction device and method

Abstract

An electro-catalysis coupled catalytic ozonation reaction device comprises a dissolution-catalysis synchronous reaction chamber and an after-dissolution electro-catalysis enhanced reaction chamber, the two chambers are connected through a flange, and a sieve plate and a backwashing water inlet are arranged at the bottom of the after-dissolution electro-catalysis enhanced reaction chamber; the dissolution-catalysis synchronous reaction chamber can realize internal circulation, and is provided with a water inlet pipe, an annular water and gas distribution system, a guide cylinder, a dissolution-catalysis synchronous catalyst, a collection conical barrel and a drain outlet; the after-dissolution electro-catalysis enhancement reaction chamber comprises a multi-stage electro-catalysis baffling first unit cylinder, an after-dissolution electro-catalysis enhancement catalyst, a second unit cylinder, a water outlet and a tail gas exhaust port; the device is also provided with a flange, a base, a direct-current power supply and the like, wherein the direct-current power supply is connected with the multi-stage electro-catalysis baffling unit cylinder through a lead. By combining the special reaction structure design, the jet device is adopted to realize gas-liquid mixing, and the jet device is used for further cutting through an annular water and gas distribution system, so that the gas dissolving efficiency is enhanced; a reactor is reasonably partitioned, and a three-dimensional electrocatalytic oxidation and catalytic ozonation coupling process is adopted to generate H2O2, hydroxyl free radicals and other high-active oxygen substances, so that the catalytic capability is improved; the internal space is optimized, the particle size of the catalyst is optimized, mass transfer among gas, liquid and solid phases is enhanced, and dissolution catalysis synchronization and after-dissolution catalysis enhancement are realized; the catalyst dosage is reduced, the energy consumption is reduced, the reaction rate is enhanced, the ozone utilization rate is improved, and the cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and in particular to an electrocatalytic coupled catalytic ozone oxidation reaction device and method. Background Art

[0002] In recent years, with the increasingly stringent sewage discharge standards, the development of efficient and low-cost wastewater deep treatment technology has become increasingly important. Catalytic ozone oxidation technology has been widely used in sewage treatment as an ideal wastewater treatment technology. The most commonly used catalytic ozone oxidation reactor is relatively simple in structure, with problems such as uneven aeration, low ozone utilization, large catalyst dosage and poor catalytic effect. The use of catalytic ozone oxidation alone is often limited by pH constraints. Catalytic ozone oxidation technology has poor treatment effects under acidic conditions. At the same time, the single ozone direct oxidation method is highly selective and cannot degrade pollutants in water in a non-targeted manner, which restricts the development of ozone catalytic oxidation technology.

[0003] It is urgent to improve the water and gas distribution method, optimize the internal space structure of the reactor, improve the gas-liquid-solid three-phase mass transfer efficiency, improve ozone utilization, reduce energy consumption, and couple other advanced oxidation processes to broaden the application scope of catalytic ozone oxidation technology. Therefore, a catalytic ozone oxidation device and method that can solve the above problems is needed. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an electrocatalytic coupled catalytic ozone oxidation reaction device and method.

[0005] The technical solution of the present invention is: an electrocatalytic coupled catalytic ozone oxidation reaction device and method include a dissolution-catalyst synchronous reaction chamber, a post-dissolution electrocatalytic enhancement reaction chamber and a direct current power supply. The dissolution-catalyst synchronous reaction chamber can realize internal circulation. The dissolution-catalyst synchronous reaction chamber is provided with a collecting cone barrel, an annular water and gas distribution system, a guide tube, a separation cone barrel and a dissolution-catalyst synchronous catalyst from bottom to top; the post-dissolution electrocatalytic enhancement reaction chamber includes a multi-stage electrocatalytic baffle unit tube and a post-dissolution electrocatalytic enhancement catalyst; the direct current power supply is connected to the multi-stage electrode baffle unit tube through a wire.

[0006] The bottom of the collecting cone barrel is provided with an annular water and gas distribution system, and the side wall of the collecting cone barrel is provided with a sewage outlet connected to the outer wall of the dissolution-catalysis synchronous reaction chamber.

[0007] The annular water and gas distribution system is arranged by 3-6 secondary ejectors connected into a ring shape through pipes, and the pipes are externally connected to the primary ejectors. After the wastewater and ozone gas are fully mixed by the primary ejectors, they enter the annular water and gas distribution system of the reactor and are further cut by the secondary ejectors to make the gas-liquid mixing more uniform.

[0008] The guide tube is welded at the center of the dissolution-catalysis synchronous reaction chamber through a bracket, the lower end of the guide tube is 3-8 cm away from the collecting cone barrel, and the upper end of the guide tube is 10-30 cm away from the separation cone barrel. The collecting cone barrel and the separation cone barrel are both fixedly connected to the inner wall of the dissolution-catalysis synchronous reaction chamber.

[0009] An opening for gas-water mixture is arranged in the center of the separation cone barrel, a sieve plate is installed at the opening, and a supporting layer is arranged between the separation cone barrel and the post-dissolution electrocatalytic enhancement reaction chamber.

[0010] The dissolution-catalyzed simultaneous catalyst may have a particle size of 0.5-2 mm, with activated carbon, zeolite, ceramsite, molecular sieve, γ-Al2O3, etc. as carrier, loaded or doped with one or more transition metal components.

[0011] The post-dissolution electrocatalytic enhanced reaction chamber is provided with a backwash water inlet, a water outlet and an exhaust gas outlet. The backwash water inlet should be arranged at the bottom of the reaction chamber, the water outlet should be arranged at the upper side wall of the reaction chamber, and the exhaust gas outlet should be arranged at the top of the reaction chamber.

[0012] The multi-stage electrocatalytic baffle unit tube is a center of a circle formed by the opening provided at the lower supporting layer of the post-dissolution electrocatalytic enhancement reaction chamber and the center of the separation cone barrel. A plurality of groups of concentric cylinders are provided at a fixed interval of 5-10 cm. The bottom of the first unit tube of the inner circle provided close to the center of the circle is welded to the supporting layer. A 3-5 cm gap is reserved between the top of the first unit tube and the top of the reactor so that it can overflow upward in the first unit tube to the second unit tube. The top of the second unit tube is welded to the top of the reactor. A 3-5 cm gap is reserved between the bottom of the second unit tube and the second supporting layer so that it can flow downward in the second unit tube to the third unit tube. The arrangement of the unit tubes is similar. The first unit tube is connected to the positive electrode of a DC power supply, the second unit tube is connected to the negative electrode of a DC power supply, the third unit tube is connected to the positive electrode of a DC power supply, and the power supply connection of the unit tubes is similar. The post-dissolution electrocatalytic enhancement catalyst is added to the gap between each unit tube.

[0013] The post-dissolution electrocatalytic enhancement catalyst may have a particle size of 3-8 mm, with activated carbon, zeolite, ceramsite, molecular sieve, metal oxide, etc. as a carrier, and loaded or doped with one or more transition metal components.

[0014] Furthermore, the structural material of the dissolution-catalysis synchronous reaction chamber and its internal collecting cone barrel, guide tube and separation cone barrel can be 316L stainless steel.

[0015] Furthermore, the anode structure material of the multi-stage electrocatalytic baffle unit tube in the post-dissolution electrocatalytic enhancement reaction chamber can be DSA material or BDD material, and the cathode structure material can be DSA material, BDD material or 316 stainless steel material.

[0016] Furthermore, the current density applied to the multi-stage electrocatalytic baffle unit cylinder in the post-dissolution electrocatalytic enhancement reaction chamber is 0.15 mA·cm -2 -8.0 mA cm -2 between.

[0017] Furthermore, the dissolution-catalysis synchronous reaction chamber and the post-dissolution electrocatalytic enhancement reaction chamber are connected by flanges, a supporting layer is arranged between the flanges, and insulating gaskets are arranged above and below the supporting layer.

[0018] Furthermore, the tail gas outlet of the post-dissolution electrocatalytic enhanced reaction chamber can be connected to a tail gas destroyer, or connected to a polytetrafluoroethylene tube to collect unused ozone and re-enter the reactor for recycling.

[0019] Furthermore, two or more multi-stage electrocatalytic baffle unit tubes may be provided in the post-dissolution electrocatalytic enhancement reaction chamber according to actual conditions.

[0020] Furthermore, the transition metal catalyst loaded or doped by the special catalyst for the solution-catalyst synchronous catalyst can be selected from at least one of titanium, cobalt, lanthanum and cerium.

[0021] Furthermore, the transition metal catalyst supported or doped by the post-dissolution electrocatalytic enhancement catalyst may be selected from at least one of iron, manganese, copper and nickel.

[0022] Furthermore, the electrocatalytic coupled catalytic ozone oxidation reaction device also includes an ozone generator, the air inlet end of the ozone generator is connected to an air source, an oxygen-rich source or a liquid oxygen source unit, and the air outlet end of the ozone generator is connected to an ozone concentration analyzer.

[0023] Furthermore, the ozone concentration analyzer is arranged between the ozone generator and the electrocatalytic coupled catalytic ozone oxidation reaction device.

[0024] In another aspect of the present invention, the present invention provides a method for catalytically oxidizing wastewater using the above-mentioned reaction device. The method comprises the following steps:

[0025] (1) The ozone produced by the ozone generator flows into the ozone concentration analyzer through a pipeline and flows out after concentration analysis;

[0026] (2) The sewage to be treated flows into the first-stage ejector through the sewage lifting pump and the sewage pipe;

[0027] (3) The ozone gas is supplied to the air inlet of the first-stage ejector through a pipeline, and is mixed with the sewage in the first-stage ejector to obtain a gas-water mixture;

[0028] (4) After the gas-water mixture enters the electrocatalytic coupled catalytic ozone oxidation reaction device, it is further cut by a secondary ejector in the annular water distribution device in the collecting cone barrel and then enters the dissolution-catalysis synchronous reaction chamber;

[0029] (5) The gas-water mixture is supplied to the dissolution-catalysis synchronous reaction chamber, and the gas-water mixture is fully mixed and contacted with the dissolution-catalysis synchronous catalyst in the dissolution-catalysis synchronous reaction chamber. The catalyst enhances the gas-liquid-solid three-phase mass transfer effect under the action of the guide tube, thereby removing part of the pollutants in the sewage. The effluent from the dissolution-catalysis synchronous reaction chamber enters the post-dissolution electrocatalysis enhancement reaction chamber through the sieve plate;

[0030] (6) The gas-water mixture enters the multi-stage electrocatalytic baffle unit cylinder in the post-dissolution electrocatalytic enhancement reaction chamber. After the unit cylinder is energized by a DC power supply connected by a wire, a closed loop is formed to perform an electro-ozone coupled catalytic oxidation reaction. The gas-water mixture passes through the first unit cylinder. Under the action of the pressure difference, the gas-water mixture entering the first unit cylinder fully reacts with the post-dissolution electrocatalytic enhancement catalyst and then enters the second unit cylinder, and the process repeats until it enters the water outlet unit.

[0031] (7) After the treatment is completed, the effluent in the post-dissolution electrocatalytic enhanced reaction chamber is discharged from the reactor through the drain port.

[0032] According to the method for catalytic oxidation of sewage according to an embodiment of the present invention, the above-mentioned reaction unit is used to make the sewage undergo multi-stage catalytic oxidation in the reaction unit under the synergistic effect of electric-ozone coupled catalytic oxidation. At the same time, the oxygen generated after the ozone reaction can be used to react in the cathode electrocatalytic baffle unit cylinder to generate highly active oxygen substances such as H2O2 and hydroxyl free radicals, thereby improving the catalytic ability of the overall reaction, strengthening the gas-liquid-solid three-phase mass transfer, and improving the utilization efficiency of ozone. The deep treatment performance of sewage is enhanced through multi-stage catalysis, and the effluent water quality of the reaction device is improved, which has good economic and environmental benefits.

[0033] The beneficial effects of the present invention are:

[0034] (1) The present invention uses a primary and secondary ejector in combination to achieve gas-liquid mixing through the primary ejector, and further cuts it through the secondary ejector in the annular water and gas distribution system to enhance the gas dissolution efficiency;

[0035] (2) The present invention realizes the simultaneous dissolution of ozone with higher efficiency and the catalytic oxidation reaction with faster speed by setting up a dissolution-catalysis synchronous reaction chamber, with short hydraulic retention time and lower cost;

[0036] (3) The present invention provides a post-dissolution electrocatalytic enhanced reaction chamber, so that the sewage undergoes multi-stage catalytic oxidation in the reaction unit under the synergistic effect of electric-ozone coupled catalytic oxidation. At the same time, the oxygen generated after the ozone reaction can be used to react in the cathode electrocatalytic baffle unit tube to generate highly active oxygen species such as H2O2 and hydroxyl free radicals, thereby improving the catalytic ability of the overall reaction, strengthening the gas-liquid-solid three-phase mass transfer, and improving the utilization efficiency of ozone;

[0037] (4) The present invention achieves higher ozone utilization rate by adding catalysts matching different reaction chambers and optimizing the catalyst particle size and the loaded active components according to the reaction characteristics of different regions, thereby achieving less catalyst addition;

[0038] (5) The present invention enhances the reaction rate, reduces energy consumption, and improves the efficiency of the catalytic ozone reaction by synergistic treatment of simultaneous dissolution and catalysis and post-dissolution electrocatalysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic diagram of a reactor structure according to an embodiment of the present invention;

[0040] Figure 2 is a schematic structural diagram of a dissolution-catalysis synchronous reaction chamber according to an embodiment of the present invention;

[0041] Figure 3 is a schematic structural diagram of a post-dissolution electrocatalytic enhancement reaction chamber according to an embodiment of the present invention;

[0042] Figure 4 It is a schematic structural diagram of a ring-shaped water distribution system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0044] Example 1: Take the circulating water discharged from a chemical plant for treatment, and its water quality characteristics are: COD=104 mg / L, pH=8.19, conductivity=5812μs / cm, treated water enters the primary ejector through a lift pump, ozone is generated by the ozone generator and then enters the primary ejector through the negative pressure generated by the primary ejector to form a gas-liquid mixture, and enters the annular water distribution system (1-2) through the water inlet pipe (1-1), and after the annular water distribution system (1-2) evenly distributes water and gas, it enters the guide tube (1-3) in the dissolution-catalysis synchronous reaction chamber (1) to form an upflow zone, and the gas-liquid mixture is fully mixed and contacted with the dissolution-catalysis synchronous catalyst (1-4), and when it reaches the separation cone barrel (1-5), the gas-liquid mixture and the catalyst form a downflow outside the guide tube to the collection cone barrel (1-6), thereby forming an internal circulation form, and as the gas-liquid mixture continues to enter, it enters the first unit barrel (3-1) in the post-dissolution electrocatalytic enhancement reaction chamber (3) through the sieve plate (2-1) provided at the flange (2), and after connecting the DC power supply, the current density is adjusted to 0.65 mA·cm-2, under the action of pressure difference, the gas-water mixture entering the first unit cylinder fully reacts with the dissolved electrocatalytic enhanced catalyst (3-2) and then enters the second unit cylinder (3-3), and then reciprocates until it enters the water outlet (3-4), and the remaining tail gas is discharged through the tail gas outlet (3-5). After being treated by the electrocatalytic coupled catalytic ozone oxidation reaction device, COD=17.6 mg / L, pH=8.23, and conductivity=4120μs / cm. The ozone utilization rate is 97.35%. Under the same operating conditions as Example 1, a commercially available tower reactor is used to fill a commercially available ozone catalyst. After treatment, the outlet water COD=53.8 mg / L, pH=8.20, conductivity=5620μs / cm, and ozone utilization rate is 72.36%. The effect is lower than that of the present reactor, and the treatment effect is improved by 35.81% and the ozone utilization rate is improved by 26.91% compared with the commercially available tower reactor filled with a commercially available ozone catalyst.

[0045] Example 2: The effluent from a biochemical pool of a pharmaceutical factory was treated after passing through a quartz sand medium filter. The effluent COD was 64 mg / L. The wastewater was treated according to the operating steps in Example 1. After being treated by the electrocatalytic coupled catalytic ozone oxidation reaction device, the COD was 12.6 mg / L, and the ozone utilization rate was 98.28%. Under the same operating conditions as Example 2, a commercially available tower reactor was filled with a commercially available ozone catalyst. After treatment, the effluent COD was 46.4 mg / L, and the ozone utilization rate was 67.45%. The effect is lower than that of this reactor, and the treatment effect is improved by 52.81% compared with the commercially available tower reactor filled with a commercially available ozone catalyst, and the ozone utilization rate is improved by 31.99%.

[0046] Example 3: Electroplating wastewater was selected as the actual wastewater, and its COD was 147 mg / L. The wastewater was treated according to the operating steps in Example 1. After being treated by the electrocatalytic coupled catalytic ozone oxidation reaction device, the COD was 19.6 mg / L, and the ozone utilization rate was 99.03%. Under the same operating conditions as Example 3, a commercially available tower reactor was filled with a commercially available ozone catalyst. After treatment, the effluent COD was 64.9 mg / L, and the ozone utilization rate was 81.45%. The effect is lower than that of this reactor, and the treatment effect is improved by 30.82% compared with the commercially available tower reactor filled with a commercially available ozone catalyst, and the ozone utilization rate is improved by 18.37%.

[0047] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An electrocatalytic coupled catalytic ozone oxidation reaction device characterized by: include: A dissolution-catalysis synchronous reaction chamber (1) and a post-dissolution electrocatalysis enhancement reaction chamber (3), the two chambers are connected by a flange (2), and a sieve plate (2-1) and a backwash water inlet (2-2) are provided at the bottom of the post-dissolution electrocatalysis enhancement reaction chamber (3); the dissolution-catalysis synchronous reaction chamber (1) can realize internal circulation, and the dissolution-catalysis synchronous reaction chamber is provided with a water inlet pipe (1-1), an annular water and gas distribution system (1-2), a guide tube (1-3), a dissolution-catalysis synchronous catalyst (1-4) separation cone barrel (1-5), a collection cone barrel (1-6) and a sewage outlet (1-7); the post-dissolution electrocatalysis enhancement reaction chamber (3) comprises a multi-stage electrocatalysis baffle first unit barrel (3-1), a post-dissolution electrocatalysis enhancement catalyst (3-2), a second unit barrel (3-3), a water outlet (3-4), and an exhaust gas outlet (3-5); the device is also provided with a flange (4), a base (5), and a DC power supply connected to the multi-stage electrocatalysis baffle unit barrel through a wire.

2. The electrocatalytic coupled catalytic ozone oxidation reaction device according to claim 1, characterized in that: The water and gas distribution system is composed of a first-stage and a second-stage ejector connected in series. After the wastewater and ozone gas are mixed by the first-stage ejector, they enter the second-stage ejector system arranged in a ring shape and enter the reactor.

3. The electrocatalytic coupled catalytic ozone oxidation reaction device according to claim 1, characterized in that: The solution-catalysis synchronous reaction chamber is filled with a catalyst with a particle size between 0.5 and 2 mm. The catalyst is supported by activated carbon, zeolite, ceramsite, molecular sieve, γ-Al2O3, etc., and loaded or doped with one or more transition metal components. The transition metal component can be selected from at least one of titanium, cobalt, lanthanum and cerium.

4. The electrocatalytic coupled catalytic ozone oxidation reaction device according to claim 1, characterized in that: The post-dissolution electrocatalytic enhancement reaction chamber is filled with a catalyst with a particle size of 3-8 mm, using activated carbon, zeolite, ceramsite, molecular sieve, γ-Al2O3, etc. as carriers, loaded or doped with one or more transition metal components, and the transition metal components can be selected from at least one of iron, manganese, copper and nickel.

5. The electrocatalytic coupled catalytic ozone oxidation reaction device according to claim 1, characterized in that: The multi-stage electrocatalytic baffle unit tubes are provided with two or more, the anode structure material can be DSA material, BDD material and the like, and the cathode structure material can be DSA material, BDD material or 316 stainless steel and the like.

6. The electrocatalytic coupled catalytic ozone oxidation reaction device according to claim 1, characterized in that: The current density applied by the multi-stage electrocatalytic baffle unit cylinder in the post-dissolution electrocatalytic enhancement reaction chamber is 0.15 mA·cm -2 -8.0 mA cm -2 between.

7. The electrocatalytic coupled catalytic ozone oxidation reaction device according to claim 1, characterized in that: It also includes an ozone generator, the air inlet of the ozone generator is connected to an air source, an oxygen-rich source or a liquid oxygen source unit, the air outlet of the ozone generator is connected to an ozone concentration analyzer, and the ozone concentration analyzer is arranged between the ozone generator and the electrocatalytic coupled catalytic ozone oxidation reaction device.

8. The method for treating wastewater using the electrocatalytic coupled catalytic ozone oxidation reaction device according to claim 1, characterized in that: include: (1) The treated water enters the primary ejector through the lifting pump. After being generated by the ozone generator, the ozone enters the primary ejector through the negative pressure generated by the primary ejector to form a gas-liquid mixture, and then enters the annular water and gas distribution system through the water inlet pipe; (2) After being evenly distributed with water and gas by the annular water and gas distribution system, the gas-liquid mixture enters the guide tube in the dissolution-catalysis synchronous reaction chamber to form an upflow zone, and the gas-liquid mixture is fully mixed and contacted with the dissolution-catalysis synchronous catalyst. When reaching the separation cone barrel, the gas-liquid mixture and the catalyst form a downflow outside the guide tube to the collection cone barrel, thereby forming an internal circulation form. As the gas-liquid mixture continues to enter, it enters the post-dissolution electrocatalytic enhancement reaction chamber through the sieve plate provided at the flange; (3) After the gas-water mixture passes through the unit cylinder and is energized by a DC power supply connected by a wire, a closed loop is formed to carry out an electro-ozone coupled catalytic oxidation reaction. Under the action of the pressure difference, the gas-water mixture entering the first unit cylinder fully reacts with the dissolved electrocatalytic enhanced catalyst and then enters the second unit cylinder, and repeats this process until it enters the water outlet. The remaining exhaust gas is discharged through the exhaust outlet.

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