Electrocatalytic coupling catalytic ozone oxidation reaction device and method

Abstract

An electrocatalytic coupled catalytic ozone oxidation reactor includes a solvent-catalyst synchronous reaction chamber and a post-solution electrocatalytic enhancement reaction chamber connected by a flange. The post-solution electrocatalytic enhancement reaction chamber has a sieve plate and a backwash inlet at its bottom. The solvent-catalyst synchronous reaction chamber can achieve internal circulation and is equipped with an inlet pipe, an annular water and gas distribution system, a guide tube, a solvent-catalyst synchronous catalyst, a collection cone, and a drain outlet. The post-solution electrocatalytic enhancement reaction chamber includes a multi-stage electrocatalytic baffle first unit, a post-solution electrocatalytic enhancement catalyst, a second unit, a water outlet, and a tail gas outlet. The device also includes a flange, a base, and a DC power supply connected to the multi-stage electrocatalytic baffle unit via wires. Combining a unique reaction structure design, a jet injector is used to achieve gas-liquid mixing, and the mixture is further segmented by an annular water and gas distribution system of the jet injector to enhance dissolved gas efficiency. The reactor is rationally partitioned, and a three-dimensional electrocatalytic oxidation and catalytic ozone oxidation coupled process is adopted to generate highly reactive oxygen species such as H2O2 and hydroxyl radicals, thereby improving catalytic capacity. The internal space is optimized, the catalyst particle size is selected, and the mass transfer between the gas, liquid, and solid phases is enhanced to achieve simultaneous dissolution and catalysis and enhanced catalysis after dissolution. The amount of catalyst added is reduced, energy consumption is lowered, the reaction rate is enhanced, ozone utilization is improved, and costs are saved.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to an electrocatalytic coupled catalytic ozone oxidation reaction device and method. Background Technology

[0002] In recent years, with increasingly stringent wastewater discharge standards, the development of efficient and low-cost advanced wastewater treatment technologies has become increasingly important. Catalytic ozone oxidation technology, as an ideal wastewater treatment technology, has been widely used in wastewater treatment. Currently, the most commonly used catalytic ozone oxidation reactors have relatively simple structures, but suffer from problems such as uneven aeration, low ozone utilization, high catalyst dosage, and poor catalytic effect. The use of catalytic ozone oxidation alone is often limited by pH; the technology is ineffective under acidic conditions. Furthermore, the single direct ozone oxidation method is highly selective and cannot indiscriminately degrade pollutants in water, thus hindering the development of ozone catalytic oxidation technology.

[0003] Improving water and gas distribution methods, optimizing the internal spatial structure of the reactor, enhancing the gas-liquid-solid three-phase mass transfer efficiency, increasing ozone utilization, reducing energy consumption, and coupling with other advanced oxidation processes to broaden the application scope of catalytic ozone oxidation technology are all urgent priorities. Therefore, the research and development of a high-performance catalytic ozone oxidation reactor is urgently needed. Thus, a catalytic ozone oxidation device and method capable of solving the aforementioned problems is required. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an electrocatalytically coupled catalytic ozone oxidation reaction apparatus and method.

[0005] The technical solution of the present invention is as follows: an electrocatalytic coupling catalytic ozone oxidation reaction device and method includes a solvent-catalyst synchronous reaction chamber 1, a post-solution electrocatalytic enhancement reaction chamber 3, and a DC power supply. The solvent-catalyst synchronous reaction chamber 1 can realize internal circulation. The solvent-catalyst synchronous reaction chamber 1 is provided with a water inlet pipe 1-1, an annular water and gas distribution system 1-2, a guide cylinder 1-3, a solvent-catalyst synchronous catalyst 1-4, a separation cone 1-5, a collection cone 1-6, and a drain outlet 1-7. The solvent-catalyst synchronous reaction chamber 1 forms an internal circulation channel for the gas-liquid mixture and the solvent-catalyst synchronous catalyst 1-4 through the cooperation of the guide cylinder 1-3, the separation cone 1-5, and the collection cone 1-6. The post-solution electrocatalytic enhancement reaction chamber 3 includes a multi-stage electrocatalytic baffle unit cylinder, a post-solution electrocatalytic enhancement catalyst 3-2, a water outlet 3-4, and a tail gas outlet 3-5. The DC power supply is connected to the multi-stage electrode baffle unit cylinder through a wire. The multi-stage electrocatalytic baffle unit cylinder includes at least a first unit cylinder 3-1 and a second unit cylinder 3-3, wherein the first unit cylinder 3-1 and the second unit cylinder 3-3 are concentrically arranged to form a baffle channel; the post-solution electrocatalytic enhancement catalyst 3-2 is filled in the gap between the multi-stage electrocatalytic baffle unit cylinders; the bottom of the post-solution electrocatalytic enhancement reaction chamber 3 is provided with a sieve plate 2-1 and a backwash inlet 2-2.

[0006] The bottom of the collecting cone is equipped with an annular water and gas distribution system 1-2, and the side wall of the collecting cone 1-6 is equipped with a drain outlet, which is connected to the outer wall of the solvent catalyst synchronous reaction chamber.

[0007] The annular water and gas distribution system 1-2 is equipped with 3-6 secondary jets connected in a ring by pipes. A primary jet is connected to the outside of the pipes. After the wastewater and ozone gas are fully mixed by the primary jet, they enter the annular water and gas distribution system 1-2, where the secondary jet further cuts the mixture to make the gas-liquid mixture more uniform.

[0008] The guide tube 1-3 is welded to the center of the solvent-catalyst synchronous reaction chamber 1 via a bracket. The lower end of the guide tube 1-3 is 3-8 cm away from the collecting cone 1-6, and the upper end of the guide tube 1-3 is 10-30 cm away from the separating cone 1-5. Both the collecting cone 1-6 and the separating cone 1-5 are fixedly connected to the inner wall of the solvent-catalyst synchronous reaction chamber 1.

[0009] The separation cone 1-5 has a gas-water mixture opening in the center, and a sieve plate 2-1 is installed at the opening. A support layer is provided between the separation cone 1-5 and the post-dissolution electrocatalytic enhancement reaction chamber 3.

[0010] The solvent-catalyst co-catalysts 1-4 can be selected with a particle size between 0.5-2 mm, using activated carbon, zeolite, ceramsite, molecular sieve, γ-Al2O3, etc. as supports, and loaded or doped with one or more transition metal components.

[0011] The post-solution electrocatalytic enhancement reaction chamber 3 is provided with a backwash inlet 2-2, an outlet 3-4 and a tail gas outlet 3-5. The backwash inlet should be located at the bottom of the reaction chamber, the outlet 3-4 should be located on the upper side wall of the reaction chamber, and the tail gas outlet 3-5 should be located at the top of the reaction chamber.

[0012] The multi-stage electrocatalytic baffle unit is a series of concentric cylinders arranged at fixed intervals of 5-10cm, with the opening at the center of the lower support layer of the post-dissolution electrocatalytic enhancement reaction chamber 3 and the center of the separation cone 1-5 as the center. The bottom of the first unit cylinder 3-1, located near the center, is welded to the support layer. A 3-5cm gap is reserved between the top of the first unit cylinder 3-1 and the top of the reactor to ensure that the flow overflows upward into the second unit cylinder 3-3. The top of the second unit cylinder 3-3 is welded to the top of the reactor. A 3-5cm gap is reserved between the bottom of the second unit cylinder 3-3 and the second support layer to ensure that the flow flows downward into the third unit cylinder. The arrangement of the unit cylinders is similar. The first unit cylinder 3-1 is connected to the positive terminal of the DC power supply, the second unit cylinder 3-3 is connected to the negative terminal of the DC power supply, and the third unit cylinder is connected to the positive terminal of the DC power supply. The power connection of the unit cylinders is similar. Post-dissolution electrocatalytic enhancement catalyst 3-2 is added between each unit cylinder.

[0013] The post-solution electrocatalytic enhancement catalyst 3-2 can be selected with a particle size between 3-8 mm, using activated carbon, zeolite, ceramsite, molecular sieve or γ-Al2O3 as a support, and loaded or doped with one or more transition metal components.

[0014] Furthermore, the solvent-catalyst synchronous reaction chamber 1 and its internal collection cone 1-6, guide tube 1-3 and separation cone 1-5 can be made of 316L stainless steel.

[0015] Furthermore, the anode structure of the multi-stage electrocatalytic baffle unit cylinder in the post-dissolution electrocatalytic enhancement reaction chamber 3 can be made of DSA material or BDD material, and the cathode structure can be made of DSA material, BDD material or 316 stainless steel material.

[0016] Furthermore, the current density applied to the multi-stage electrocatalytic baffle unit cylinder within the post-dissolution electrocatalytic enhancement reaction chamber 3 is 0.15 mA·cm⁻¹. -2 -8.0 mA·cm -2 between.

[0017] Furthermore, the solvent-catalyst synchronous reaction chamber 1 and the post-solution electrocatalytic enhancement reaction chamber 3 are connected by a first flange 2, a support layer is provided between the flanges, and insulating gaskets are provided above and below the support layer.

[0018] Furthermore, the tail gas outlet 3-5 of the post-dissolution electrocatalytic enhancement reaction chamber 3 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, the multi-stage electrocatalytic baffle unit cylinder in the post-dissolution electrocatalytic enhancement reaction chamber 3 can be set in two or more according to actual needs.

[0020] Furthermore, the transition metal catalyst supported or doped on the solvent-catalyst co-catalyst 1-4 can be selected from at least one of titanium, cobalt, lanthanum and cerium.

[0021] Furthermore, the transition metal catalyst supported or doped on the post-solution electrocatalytic enhancement catalyst 3-2 may be selected from at least one of iron, manganese, copper and nickel.

[0022] Furthermore, the electrocatalytic coupled catalytic ozone oxidation reactor is also equipped with a second flange 4 and a base 5.

[0023] Furthermore, the electrocatalytic coupling catalytic ozone oxidation reaction device also includes an ozone generator, the ozone generator's inlet end being connected to an air source, an oxygen-enriched source, or a liquid oxygen source unit, and the ozone generator's outlet end being connected to an ozone concentration analyzer.

[0024] Furthermore, the ozone concentration analyzer is located between the ozone generator and the electrocatalytic coupling catalytic ozone oxidation reaction device.

[0025] In another aspect of the invention, a method for catalytic oxidation of wastewater using the reaction apparatus described above is provided. The method includes the following steps: (1) The treated water enters the first-stage jet pump through the booster pump. After the ozone is generated by the ozone generator, it enters the first-stage jet pump through the negative pressure generated by the first-stage jet pump to form a gas-liquid mixture. It then enters the annular water and gas distribution system 1-2 through the water inlet pipe 1-1. (2) After the water and gas are evenly distributed by the annular water and gas distribution system 1-2, the gas enters the guide tube 1-3 in the solvent-catalyst synchronous reaction chamber 1 to form an upflow zone. The gas-liquid mixture is fully mixed and contacted with the solvent-catalyst synchronous catalyst 1-4. When it reaches the separation cone 1-5, the gas-liquid mixture and the catalyst form a downflow outside the guide tube and flows to the collection cone 1-6, thus forming a gas-liquid-solid three-phase internal circulation. (3) As the gas-liquid mixture continues to enter, it enters the post-dissolution electrocatalytic enhancement reaction chamber 3 through the sieve plate 2-1 set at the first flange 2; (4) The gas-water mixture enters the multi-stage electrocatalytic baffle unit cylinder. After being energized by a DC power supply, a closed loop is formed between the multi-stage electrocatalytic baffle unit cylinders to carry out an electro-ozone coupled catalytic oxidation reaction. Under the action of pressure difference, the gas-water mixture flows sequentially through the first unit cylinder 3-1, the dissolved electrocatalytic enhancement catalyst 3-2 filled in the gap between the unit cylinders, and the second unit cylinder 3-3, and so on until it enters the water outlet 3-4. The remaining tail gas is discharged through the tail gas outlet 3-5.

[0026] According to the present invention, the method for catalytic oxidation of wastewater employs the above-mentioned reaction unit, enabling wastewater to undergo multi-stage catalytic oxidation within the reaction unit under the synergistic effect of electro-ozone coupled catalytic oxidation. Simultaneously, the oxygen generated after the ozone reaction can be utilized to react in the cathode electrocatalytic baffle unit to generate highly reactive oxygen species such as H2O2 and hydroxyl radicals, thereby improving the overall catalytic capacity of the reaction, enhancing the gas-liquid-solid three-phase mass transfer, and improving the ozone utilization efficiency. Through multi-stage catalysis, the deep treatment performance of wastewater is enhanced, and the effluent quality of the reaction device is improved, resulting in good economic and environmental benefits.

[0027] The beneficial effects of this invention are: (1) The present invention uses a combination of primary and secondary jet injectors. The primary jet injector achieves gas-liquid mixing, and the secondary jet injector in the annular water and gas distribution system further cuts the gas and enhances the dissolved gas efficiency. (2) By setting up a simultaneous reaction chamber for dissolution and catalysis, the present invention achieves simultaneous ozone dissolution with higher efficiency and faster catalytic oxidation reaction, with shorter hydraulic residence time and lower cost; (3) By setting up a post-dissolution electrocatalytic enhanced reaction chamber, the wastewater can undergo multi-stage catalytic oxidation in the reaction unit under the synergistic effect of electro-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 to generate highly active oxygen substances such as H2O2 and hydroxyl radicals, thereby improving the overall catalytic ability of the reaction, strengthening the gas-liquid-solid three-phase mass transfer, and improving the utilization efficiency of ozone. (4) By adding a catalyst that matches the reaction chamber to different reaction chambers, the present invention optimizes the catalyst particle size and the active component loaded according to the reaction characteristics of different regions, thereby achieving less catalyst addition and higher ozone utilization. (5) This invention enhances the reaction rate, reduces energy consumption, and improves the efficiency of catalytic ozone reaction by simultaneously treating the solvent and catalyst and enhancing the electrocatalysis after solvent treatment. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a reactor structure according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a solvent-catalyst simultaneous reaction chamber according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the structure of a post-solution electrocatalytic enhancement reaction chamber according to an embodiment of the present invention. Figure 4 This is a schematic diagram of a ring-shaped water distribution system according to an embodiment of the present invention. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0030] Example 1: Wastewater from a chemical plant's circulating system was treated. Its characteristics were: COD = 104 mg / L, pH = 8.19, conductivity = 5812 μS / cm. The treated water entered the primary ejector via a booster pump. Ozone, generated by an ozone generator, entered the primary ejector under negative pressure, forming a gas-liquid mixture. This mixture then entered the annular water distribution system 1-2 through inlet pipe 1-1. After uniform water and gas distribution by the annular system 1-2, it entered the guide tube 1-3 within the solvent-catalyst synchronous reaction chamber 1, forming an upflow zone. The gas-liquid mixture fully mixed and contacted with the solvent-catalyst synchronous catalyst 1-4. Upon reaching the separation cone 1-5, the gas-liquid mixture and catalyst formed a downflow outside the guide tube, flowing into the collection cone 1-6, thus forming an internal circulation. As the gas-liquid mixture continued to enter, it passed through the sieve plate 2-1 at the first flange 2 into the first unit cylinder 3-1 within the post-solution electrocatalytic enhancement reaction chamber 3. After connecting to a DC power supply, the current density was adjusted to 0.65 mA·cm. -2 Under the action of pressure difference, the gas-water mixture entering the first unit cylinder reacts fully with the dissolved electrocatalytic enhancement catalyst 3-2 before entering the second unit cylinder 3-3. This process is repeated until it enters the outlet 3-4, and the remaining tail gas is discharged through the tail gas outlet 3-5. After treatment by this electrocatalytic coupled catalytic ozone oxidation reactor, the COD is 17.6 mg / L, pH is 8.23, conductivity is 4120 μS / cm, and ozone utilization is 97.35%. Under the same operating conditions as in Example 1, using a commercially available tower reactor filled with a commercially available ozone catalyst, the treated water has a COD of 53.8 mg / L, pH is 8.20, conductivity is 5620 μS / cm, and ozone utilization is 72.36%. The effect is lower than that of this reactor, but the treatment effect is improved by 35.81% and the ozone utilization is improved by 26.91% compared to the commercially available tower reactor filled with a commercially available ozone catalyst.

[0031] Example 2: Wastewater from a pharmaceutical factory's biochemical treatment tank, after passing through a quartz sand media filter, had a COD of 64 mg / L. Following the operating steps in Example 1, the wastewater was treated using this electrocatalytic coupled-catalytic ozone oxidation reactor, resulting in a COD of 12.6 mg / L and an ozone utilization rate of 98.28%. Under the same operating conditions as in Example 2, a commercially available tower reactor filled with a commercially available ozone catalyst was used. After treatment, the effluent COD was 46.4 mg / L, and the ozone utilization rate was 67.45%. The effect was lower than that of this reactor, but the treatment effect was improved by 52.81% and the ozone utilization rate was improved by 31.99% compared to the commercially available tower reactor filled with a commercially available ozone catalyst.

[0032] Example 3: Electroplating wastewater with a COD of 147 mg / L was selected as the actual wastewater. Following the operating steps in Example 1, the wastewater was treated using an electrocatalytically coupled ozone oxidation reactor. After treatment, the COD was 19.6 mg / L, and the ozone utilization rate was 99.03%. Under the same operating conditions as in Example 3, a commercially available tower reactor filled with a commercially available ozone catalyst was used. After treatment, the effluent COD was 64.9 mg / L, and the ozone utilization rate was 81.45%. The effect was lower than that of the original reactor, but the treatment effect was improved by 30.82% and the ozone utilization rate was improved by 18.37% compared to a commercially available tower reactor filled with a commercially available ozone catalyst.

[0033] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An electrocatalytically coupled catalytic ozone oxidation reactor, characterized in that, include: The solvent-catalyst synchronous reaction chamber (1) and the post-solution electrocatalytic enhancement reaction chamber (3) are connected by a first flange (2). The solvent-catalyst synchronous reaction chamber (1) is equipped with a water inlet pipe (1-1), an annular water and gas distribution system (1-2), a guide tube (1-3), a solvent-catalyst synchronous catalyst (1-4), a separation cone (1-5), a collection cone (1-6), and a drain outlet (1-7). The solvent-catalyst synchronous reaction chamber (1) forms a gas-liquid mixture with the solvent through the cooperation of the guide tube (1-3), the separation cone (1-5), and the collection cone (1-6). The internal circulation channel of the synchronous catalyst (1-4); the post-solution electrocatalytic enhancement reaction chamber (3) includes a multi-stage electrocatalytic baffle unit cylinder, a post-solution electrocatalytic enhancement catalyst (3-2), a water outlet (3-4), and a tail gas outlet (3-5); the multi-stage electrocatalytic baffle unit cylinder includes at least a first unit cylinder (3-1) and a second unit cylinder (3-3), the first unit cylinder (3-1) and the second unit cylinder (3-3) are concentrically arranged and form a baffle channel; the post-solution electrocatalytic enhancement catalyst (3-2) is filled in the multi-stage electrocatalytic baffle unit cylinder. In the gap between them; the bottom of the electrocatalytic enhancement reaction chamber (3) after dissolution is provided with a sieve plate (2-1) and a backwash inlet (2-2); the device is also provided with a second flange (4), a base (5) and a DC power supply connected to the multi-stage electrocatalytic baffle unit cylinder through a wire; the electrocatalytic coupling catalytic ozone oxidation reaction device also includes a primary jet, the annular water and gas distribution system (1-2) is arranged with 3-6 secondary jets connected in a ring by pipes, the pipes are connected to the primary jet, and the wastewater and ozone gas are fully mixed by the primary jet before entering the annular water and gas distribution system. The system (1-2) is further cut by a secondary jet injector to make the gas-liquid mixture more uniform; the solvent-catalyst co-catalyst (1-4) has a particle size of 0.5-2 mm, and uses activated carbon, zeolite, ceramsite, molecular sieve or γ-Al2O3 as a support, and is loaded or doped with at least one transition metal component selected from titanium, cobalt, lanthanum and cerium; the post-solution electrocatalytic enhancement catalyst (3-2) has a particle size of 3-8 mm, and uses activated carbon, zeolite, ceramsite, molecular sieve or γ-Al2O3 as a support, and is loaded or doped with at least one transition metal component selected from iron, manganese, copper and nickel.

2. The electrocatalytic coupled catalytic ozone oxidation reactor according to claim 1, characterized in that, The anode structure of the multi-stage electrocatalytic baffle unit is made of DSA or BDD material, and the cathode structure is made of DSA, BDD or 316 stainless steel.

3. A method for wastewater treatment using the electrocatalytic coupled catalytic ozone oxidation reactor as described in any one of claims 1 to 2, characterized in that, Includes the following steps: (1) The treated water enters the first-stage jet pump through the booster pump. After the ozone is generated by the ozone generator, it enters the first-stage jet pump through the negative pressure generated by the first-stage jet pump to form a gas-liquid mixture. It then enters the annular water and gas distribution system (1-2) through the water inlet pipe (1-1). (2) After being uniformly distributed by the annular water and gas distribution system (1-2), the gas enters the guide tube (1-3) in the solvent-catalyst synchronous reaction chamber (1) to form an upflow zone. The gas-liquid mixture is fully mixed and contacted with the solvent-catalyst synchronous catalyst (1-4). When it reaches the separation cone (1-5), the gas-liquid mixture and the catalyst form a downflow outside the guide tube and flow to the collection cone (1-6), thus forming a gas-liquid-solid three-phase internal circulation. (3) As the gas-liquid mixture continues to enter, it enters the post-dissolution electrocatalytic enhancement reaction chamber (3) through the sieve plate (2-1) set at the first flange (2). (4) The gas-liquid mixture enters the multi-stage electrocatalytic baffle unit cylinder. After being energized by a DC power supply, a closed loop is formed between the multi-stage electrocatalytic baffle unit cylinders to carry out an electro-ozone coupled catalytic oxidation reaction. Under the action of pressure difference, the gas-liquid mixture flows sequentially through the first unit cylinder (3-1), the dissolved electrocatalytic enhancement catalyst (3-2) filling the gap between the unit cylinders, and the second unit cylinder (3-3), and repeats this process until it enters the water outlet (3-4). The remaining tail gas is discharged through the tail gas outlet (3-5).

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