Ozone catalytic oxidation treatment system and method based on gas-liquid reinforced disturbance pressurized gas

Abstract

This invention discloses an ozone catalytic oxidation treatment system and method based on gas-liquid enhanced perturbation pressurized dissolved gas, comprising a heterogeneous ozone catalytic oxidation unit, a gas-liquid enhanced perturbation pressurized dissolved gas unit, an ozone generation unit, an oxygen production unit, and a tail gas drying, decomposition, and storage unit. The oxygen production unit is connected to the gas-liquid enhanced perturbation pressurized dissolved gas unit via the ozone generation unit, the gas-liquid enhanced perturbation pressurized dissolved gas unit is connected to the tail gas drying, decomposition, and storage unit via the heterogeneous ozone catalytic oxidation unit, and the tail gas drying, decomposition, and storage unit is connected to the ozone generation unit. This invention integrates the ozone catalytic oxidation technology into a system structure and optimizes the process method, improving the ozone and oxygen utilization rate and reaction rate of the ozone catalytic oxidation treatment technology, saving energy and reducing consumption, lowering the comprehensive treatment cost of wastewater, and improving the treatment effect. It is well applied to the treatment of organic wastewater of different concentrations, such as power plant circulating water discharge, circulating water makeup water, and desulfurization wastewater.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to an ozone catalytic oxidation treatment system and method based on gas-liquid enhanced disturbance pressurized dissolved gas. Background Technology

[0002] With increasingly stringent water consumption controls and environmental policies, thermal power plants need to gradually replace their fresh water supply sources and recycle wastewater. Currently, most power plants in northern China are gradually replacing their circulating water supply with urban reclaimed water and treating and reusing the wastewater. Urban reclaimed water contains recalcitrant organic matter, which, after concentration in cooling towers, significantly increases the risk of corrosion and fouling, typically requiring large amounts of scale inhibitors, corrosion inhibitors, and water stabilizers to mitigate these risks. The concentration of recalcitrant organic matter in the wastewater further increases after concentration in cooling towers, and the presence of added scale inhibitors and stabilizers further negatively impacts the normal operation of subsequent coagulation sedimentation and reverse osmosis desalination reuse systems. Therefore, strengthening the efficient removal of organic matter is crucial for the safe operation of circulating water systems and is key to achieving deep water conservation, emission reduction, energy saving, and improved efficiency in power plants.

[0003] Ozone catalytic oxidation technology, as an advanced oxidation process, has been widely used in recent years for the treatment of organic wastewater of various concentrations in industries such as coking, petrochemicals, printing and dyeing, oil refining, coal chemicals, pharmaceuticals, papermaking, and brewing. Compared with ozone oxidation technology, ozone catalytic oxidation generates hydroxyl radicals with stronger oxidation capabilities, faster oxidation rates, and no selectivity, resulting in a high organic matter mineralization rate. It also has advantages such as decolorization, deodorization, and sterilization. Due to its good treatment effect and lack of secondary pollution, it holds a significant advantage in water treatment technology.

[0004] In ozone catalytic oxidation technology, the solubility of ozone in wastewater significantly impacts mass transfer efficiency, ozone utilization efficiency, and treatment effect. Traditional ozone catalytic oxidation technology suffers from the following problems: ① Low ozone solubility: The solubility rate of ozone added via aeration discs and jets is generally less than 70%, resulting in low efficiency of the ozone dissolved gas diffusion system, producing large-diameter bubbles with small specific surface areas, short residence times, and low mass transfer efficiency. ② Low efficiency in converting oxygen to ozone: Ozone conversion efficiency of oxygen-source ozone generators is only about 10%, with the remaining 90% of unconverted oxygen being discharged after tail gas treatment, leading to energy waste. ③ Inaccurate ozone dosing: Ozone is often added proportionally based on the volume of water to be treated, resulting in either overdosing and waste or underdosing leading to substandard effluent quality, and poor resistance to water quality fluctuations. ④ In actual operation, excessive ozone dosing is often used to ensure effluent quality meets standards, resulting in low ozone utilization efficiency, high energy consumption, and significantly increased operating costs, hindering the widespread application of this technology in water treatment. Summary of the Invention

[0005] To address the deficiencies in the prior art, the present invention provides an ozone catalytic oxidation treatment system and method based on gas-liquid enhanced disturbance pressurized dissolved air, which feature high ozone dissolution rate and utilization rate, high oxygen utilization rate, precise oxygen production, accurate ozone dosing, good adaptability to water quality and quantity, high economy and efficiency, and high automation. It can efficiently and cost-effectively treat urban reclaimed water and recycled sewage effluent, assist enterprises in achieving deep water conservation and emission reduction, and ultimately achieve the goal of intensive and economical utilization of water resources.

[0006] To achieve the above objectives, the present invention adopts the following technical solutions:

[0007] An ozone catalytic oxidation treatment system based on gas-liquid enhanced disturbance pressurized dissolved air includes a heterogeneous ozone catalytic oxidation unit, a gas-liquid enhanced disturbance pressurized dissolved air unit, an ozone generation unit, an oxygen production unit, and a tail gas drying, decomposition, and storage unit.

[0008] Among them, the oxygen production unit is connected to the ozone generation unit, the ozone generation unit is connected to the gas-liquid enhanced disturbance pressurized dissolved air unit, the gas-liquid enhanced disturbance pressurized dissolved air unit is connected to the heterogeneous ozone catalytic oxidation unit, the heterogeneous ozone catalytic oxidation unit is connected to the tail gas drying, decomposition, and storage unit, and the tail gas drying, decomposition, and storage unit is connected to the ozone generation unit.

[0009] Further, the heterogeneous ozone catalytic oxidation unit includes a heterogeneous ozone catalytic oxidation tower, which includes a catalytic oxidation tower shell. Inside the catalytic oxidation tower shell, catalytic oxidation fillers are provided. Above the catalytic oxidation fillers is a clear water area, and at the top of the clear water area is a tail gas discharge port. Below the catalytic oxidation tower fillers is a buffer area, and at the bottom of the buffer area are evenly distributed multiple dissolved air water distributors.

[0010] Further, at the bottom of the catalytic oxidation tower shell is a dissolved air water interface, and above the clear water area on the catalytic oxidation tower shell is a reflux port; each dissolved air water distributor is respectively connected to a dissolved air water main pipe, presenting a rich character structure; the dissolved air water main pipe is connected to the dissolved air water interface on the catalytic oxidation tower shell, and the reflux port is connected to the gas-liquid enhanced disturbance pressurized dissolved air unit.

[0011] Further, the gas-liquid enhanced disturbance pressurized dissolved air unit includes a reflux pipeline, a dissolved air pressurization pump, a gas-liquid enhanced disturbance pressurized dissolved air device, and a dissolved air water pipeline connected in sequence. The head end of the reflux pipeline is connected to the reflux port of the heterogeneous ozone catalytic oxidation unit, and the end of the dissolved air water pipeline is connected to the dissolved air water interface.

[0012] Furthermore, the gas-liquid enhanced turbulence pressurized dissolved gas device includes an outer shell and internal components disposed inside the outer shell. The outer shell is cylindrical with a height-to-diameter ratio of 4:1 to 5:1. A water inlet is provided at the lower end of the outer shell, an air inlet is provided at the upper end of the water inlet, and a water outlet is provided at the upper end of the outer shell. The water inlet is connected to the outlet of the dissolved gas pressurization pump, the water outlet is connected to the beginning of the dissolved gas water pipeline, and the air inlet is connected to the outlet of the ozone generating unit.

[0013] Furthermore, the internal components include a water distribution pipe, an air distribution pipe, and a labyrinth-type gas-liquid disturbance device. The first end of the water distribution pipe is connected to the water inlet, the first end of the air distribution pipe is connected to the air inlet, and the labyrinth-type gas-liquid disturbance device is located above the air inlet.

[0014] Furthermore, the water distribution pipe and the air distribution pipe adopt a T-shaped water and air distribution main and branch pipe arrangement, horizontally arranged, with the ends of the main pipe and branch pipes sealed; the water distribution branch pipe and the air distribution branch pipe are double-layered wire-wound tubes, including an inner round tube and an outer wire-wound tube, with the inner round tubes arranged alternately downwards at a 45° angle to the horizontal every 100-200mm on both sides along the length direction. The jetting circular vent has an outer layer of wire tube wrapped around an inner layer of circular tube along its length. The diameter of the outer layer of wire tube is 5 to 10 mm larger than that of the inner layer of circular tube, and the spacing between adjacent wires in the outer layer of wire tube is 0.2 to 0.5 mm.

[0015] The labyrinth-type gas-liquid disturbance device consists of flow-reflecting cones arranged alternately in the vertical and horizontal directions along the height direction; the flow-reflecting cones of the labyrinth-type gas-liquid disturbance device are arranged in 4 to 10 layers, the apex angle of each layer of the reflection cone is 45 to 90°, the horizontal distance between adjacent reflection cones is 1 to 2 cm, the width of the bottom surface of the reflection cone is 2 to 5 times the distance between the reflection cones, and the distance between two adjacent layers of reflection cones is 5 to 15 cm.

[0016] Furthermore, the ozone generating unit includes an ozone generator and a gas compressor connected in sequence, and the gas compressor is connected to a gas-liquid enhanced perturbation pressurized dissolved gas device;

[0017] The exhaust gas drying, decomposition, and storage unit includes a dryer, an ozone decomposition reactor, and an oxygen storage tank connected in sequence. The dryer is connected to a heterogeneous ozone catalytic oxidation unit, and the oxygen storage tank is connected to an ozone generation unit.

[0018] An ozone catalytic oxidation treatment method based on gas-liquid enhanced perturbation pressurized dissolved gas includes the following steps:

[0019] The organic wastewater to be treated enters the heterogeneous ozone catalytic oxidation unit, where the organic pollutants in the wastewater are initially degraded. Then, a portion of the wastewater is recycled into the gas-liquid enhanced disturbance pressurized dissolved gas unit to form high-pressure, high-speed water gas. The remaining wastewater flows out of the heterogeneous ozone catalytic oxidation unit. The remaining undissolved oxygen and unreacted ozone gas enter the tail gas drying, decomposition and storage unit. The unreacted ozone gas is converted into oxygen. The oxygen in the tail gas drying, decomposition and storage unit and the oxygen in the oxygen generation unit enter the ozone generation unit to form high-pressure ozone.

[0020] After high-pressure, high-speed water vapor and high-pressure ozone are uniformly distributed through high-frequency cutting, a uniformly dispersed gas-liquid mixture is formed. Then, it rises at the same flow rate and enters the labyrinth-type gas-liquid disturbance device. After being blocked and cut by multiple layers of alternating longitudinal and transverse flow-reflecting cones, the water-gas flow state changes drastically, forming a high-speed reversal motion. The degree of turbulence increases, causing the water vapor to quickly dissolve and form a highly mixed gas-liquid mixture. Then, it enters the heterogeneous ozone catalytic oxidation unit to remove the remaining organic matter.

[0021] Furthermore, the oxygen production capacity of the oxygen generation unit is calculated using the following formula:

[0022]

[0023] In the formula:

[0024] Q0—Oxygen production capacity of the oxygen generation unit, m 3 / h;

[0025] Q—Inlet flow rate, m 3 / h;

[0026] Q1—Exhaust gas flow rate, m 3 / h;

[0027] S0—Influent COD concentration, mg / L;

[0028] S e —Effluent COD concentration, mg / L;

[0029] C0—Ozone concentration at the ozone generator outlet, mg / L;

[0030] C1 — Ozone concentration in the reaction liquid phase, mg / L;

[0031] C2—Ozone concentration in exhaust gas, mg / L;

[0032] a—Ozone consumption per unit of COD removed;

[0033] b—reflux ratio;

[0034] k1—First correction factor;

[0035] k2—Second correction coefficient.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] This invention integrates and optimizes the ozone catalytic oxidation technology by setting up an ozone catalytic oxidation unit and a gas-liquid enhanced perturbation pressurized dissolved gas unit. This solves the problems of low ozone dissolution rate, low mass transfer efficiency and utilization rate, and low oxygen utilization rate in existing ozone catalytic oxidation technologies. It improves the ozone and oxygen utilization rate and reaction rate of ozone catalytic oxidation treatment technology, saves energy and reduces consumption, lowers the comprehensive treatment cost of wastewater, and improves the treatment effect. It can be well applied to the treatment of organic wastewater of different concentrations, such as power plant circulating water discharge, circulating water makeup water, and desulfurization wastewater.

[0038] Furthermore, this invention employs a pressurized dissolved air method that regulates water and air pressure to adjust the partial pressure of ozone in water, thereby increasing the solubility of ozone in water. Simultaneously, the pressurized mixed fluid is efficiently mixed and stirred by a high-resistance water and air distribution device and a labyrinth-type ozone high-frequency disturbance device, improving the uniformity of water and air distribution, enhancing turbulence, increasing diffusion effect, and improving mixing and mass transfer efficiency, further enhancing the uniformity and solubility of ozone dissolution. In this invention, the uniformly mixed pressurized dissolved air water is refluxed through the reaction liquid, allowing the unreacted ozone dissolved in the liquid phase to continue participating in the reaction, improving ozone reaction efficiency and utilization, reducing ozone production, and lowering energy consumption.

[0039] This invention collects unreacted ozone and most of the oxygen that has not been converted into ozone from the exhaust gas, processes it, and then reuses it as an oxygen source, thereby improving oxygen utilization and reducing the oxygen production cost of ozone treatment. This invention proposes a precise ozone dosing method based on the coordinated control of multiple parameters, including influent and effluent water quality, quantity, and ozone concentration. The method can automatically and precisely control the oxygen production and ozone dosage in real time based on online water quality, quantity, and ozone concentration readings, achieving precise ozone dosing, saving ozone consumption, reducing system energy consumption, and ensuring good treatment results even under drastic fluctuations in water quality and quantity. It has strong shock resistance. Compared with traditional ozone catalytic oxidation processes, this invention effectively reduces wastewater treatment costs and has good economic benefits. Attached Figure Description

[0040] Figure 1 This is a process flow diagram of the system of the present invention;

[0041] Figure 2 A schematic diagram of a gas-liquid enhanced perturbation pressurized dissolved gas device;

[0042] Figure 3 A schematic diagram of the planar structure of the water and gas distribution device and the labyrinth-type gas-liquid disturbance device;

[0043] Figure 4 This is a schematic diagram of the structure of the flow-reflecting cone.

[0044] In the diagram, 1-Heterogeneous ozone catalytic oxidation unit, 2-Gas-liquid enhanced disturbance pressurized dissolved gas unit, 2-1-Outer shell, 2-2-Internal components, 2-1-1-Water inlet, 2-1-2-Air inlet, 2-1-3-Water outlet, 2-2-1-Water distribution pipe, 2-2-2-Air distribution pipe, 2-2-3-Maze-type gas-liquid disturbance device, 2-2-3-1-Flow-around reflective cone, 2-2-1-1-Water distribution branch pipe, 2-2-2-1-Air distribution branch pipe, 3-Ozone generating unit, 4-Oxygen production unit, 5-Tail gas drying, decomposition and storage unit. Detailed Implementation

[0045] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0046] Furthermore, elements in this invention are referred to as being "fixed to" or "set on" another element, which may be directly on the other element or may also include an intervening element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or may also include an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementations.

[0047] This invention integrates the system structure and optimizes the process of ozone catalytic oxidation technology, solving problems such as low ozone dissolution rate, low mass transfer efficiency and utilization rate of ozone catalytic reaction, and low oxygen utilization rate in existing ozone catalytic oxidation technologies. It further improves the utilization rate of ozone and oxygen and the reaction rate of ozone catalytic oxidation treatment technology, reduces the comprehensive treatment cost of wastewater, enhances the system's resistance to shocks, and improves the treatment effect.

[0048] See Figures 1-4 The present invention provides an ozone catalytic oxidation treatment system based on gas-liquid enhanced perturbation pressurized dissolved gas, comprising a heterogeneous ozone catalytic oxidation unit 1, a gas-liquid enhanced perturbation pressurized dissolved gas unit 2, an ozone generation unit 3, an oxygen production unit 4, and a tail gas drying, decomposition, and storage unit 5.

[0049] Among them, the oxygen generation unit 4 is connected to the ozone generation unit 3, the ozone generation unit 3 is connected to the gas-liquid enhanced disturbance pressurized dissolved air unit 2, the gas-liquid enhanced disturbance pressurized dissolved air unit 2 is connected to the heterogeneous ozone catalytic oxidation unit 1, the heterogeneous ozone catalytic oxidation unit 1 is connected to the tail gas drying decomposition storage unit 5, and the tail gas drying decomposition storage unit 5 is connected to the ozone generation unit 3.

[0050] Further, the heterogeneous ozone catalytic oxidation unit 1 includes a heterogeneous ozone catalytic oxidation tower, and the heterogeneous ozone catalytic oxidation tower includes a catalytic oxidation tower shell. Specifically, a catalytic oxidation filler is provided inside the catalytic oxidation tower shell, and the filler height is 1.5 - 2 m, providing a catalytic oxidation reaction site for ozone and organic substances. There is a clear water area with a height of 2 m above the catalytic oxidation filler, where ozone oxidation occurs, prolonging the ozone reaction time, and improving the oxidation efficiency and ozone utilization rate. There is a tail gas discharge port with a height of 0.5 m at the top of the clear water area, used for discharging the remaining unreacted ozone gas and oxygen. The buffer area at the lower part of the catalytic oxidation tower filler has a height of 1 m, used for water and gas distribution; a plurality of dissolved air water distributors are evenly arranged at the bottom of the buffer area, used for evenly distributing pressurized dissolved air water at the bottom of the heterogeneous ozone catalytic oxidation tower; each dissolved air water distributor is respectively and proximately connected to the dissolved air water main pipe at the bottom of the tower, presenting a "rich" character structure, making the flow rate of the dissolved air water uniform along the cross-section of the heterogeneous ozone catalytic oxidation tower, avoiding the phenomena of uneven flow and short circuit; the dissolved air water main pipe is connected to the dissolved air water interface on the catalytic oxidation tower shell. There is a reflux port at the upper part of the clear water area on the catalytic oxidation tower shell, used for refluxing part of the reaction liquid to the gas-liquid enhanced disturbance pressurized dissolved air unit 2.

[0051] Further, the gas-liquid enhanced disturbance pressurized dissolved air unit 2 includes a reflux pipeline, a dissolved air pressurizing pump, a gas-liquid enhanced disturbance pressurized dissolved air device, and a dissolved air water pipeline connected in sequence. The head end of the reflux pipeline and the tail end of the dissolved air water pipeline are respectively connected to the reflux port and the dissolved air water interface of the heterogeneous ozone catalytic oxidation unit, and the dissolved air pressurizing pump is used to boost the pressure of the reflux reaction liquid to meet the inlet requirement of the dissolved air pressure of the gas-liquid enhanced disturbance pressurized dissolved air device. Specifically, see Figure 2, the gas-liquid enhanced disturbance pressurized dissolved air device includes a housing 2-1 and internal components 2-2 disposed inside the housing 2-1. Among them, the housing 2-1 is a slender cylindrical shape with a height-to-diameter ratio of 4:1 to 5:1. An inlet 2-1-1 is provided 0.2 m above the lower end of the housing 2-1. An air inlet 2-1-2 is provided 0.3 m above the upper end of the inlet 2-1-1. An outlet 2-1-3 is provided 0.2 m below the upper end of the housing 2-1. The inlet 2-1-1 is connected to the outlet of the dissolved air pressurization pump. The outlet 2-1-3 is connected to the head end of the dissolved air water pipeline. The air inlet is connected to the outlet of the gas compressor of the ozone generation unit 3; the internal components 2-2 include a water distribution pipe 2-2-1, a gas distribution pipe 2-2-2, and a labyrinth gas-liquid disturbance device 2-2-3. The head end of the water distribution pipe 2-2-1 is connected to the inlet 2-1-1. The head end of the gas distribution pipe 2-2-2 is connected to the air inlet 2-1-2. The water distribution pipe 2-2-1 and the gas distribution pipe 2-2-2 adopt a "rich" shaped large-resistance water and gas distribution main and branch pipes, which are horizontally arranged. The ends of the main pipe and the branch pipes are tightly blocked by blind plates to achieve the effect of uniform water and gas distribution along the horizontal section of the device; the water distribution branch pipe 2-2-1-1 and the gas distribution branch pipe 2-2-2-1 are double-layer wire-wound pipes, including an inner layer circular pipe and an outer layer wire-wound pipe. The inner layer circular pipe is alternately arranged downward at a 45° angle with the horizontal every 100 - 200 mm along both sides in the length direction Jet round air holes. The outer layer wire-wound pipe is wrapped around the inner layer circular pipe along the length direction. The diameter of the outer layer wire-wound pipe is 5 - 10 mm larger than the diameter of the inner layer circular pipe. The adjacent wire spacing of the outer layer wire-wound pipe is 0.2 - 0.5 mm. The smaller holes of the inner layer circular pipe increase the hole flow velocity of high-pressure water and gas, forming a jet. The outer layer wire-wound gaps further cut the water and gas forming the jet at high frequency, enabling the rapid mixing of water and gas. After forming a uniformly dispersed gas-liquid mixed fluid, it rises and enters the labyrinth gas-liquid disturbance device 2-2-3; see Figure 3 and Figure 4 , the labyrinth gas-liquid disturbance device 2-2-3 is located 0.3 m above the air inlet 2-1-2 and is composed of flow-around reflection cones 2-2-3-1 arranged horizontally and alternately in the vertical and horizontal directions along the height direction; the flow-around reflection cones 2-2-3-1 of the labyrinth gas-liquid disturbance device are arranged in 4 - 10 layers. The apex angle of each layer of reflection cone is 45 - 90°. The horizontal distance between adjacent reflection cones is 1 - 2 cm. The bottom width of the reflection cone is 2 - 5 times the distance between the reflection cones. The distance between adjacent two layers of reflection cones is 5 - 15 cm. Because the reflection cones themselves occupy part of the flow-through channel area, the flow velocity of the mixed fluid is increased. By using the blocking effect of the reflection cones, the initially formed dissolved air water continuously moves irregularly back and forth along the reflection cones, causing high-frequency disturbance to the sewage, strengthening the degree of turbulence, making molecular collisions more frequent. At the same time, the cutting of the cone angle causes the bubbles to burst and the diameter to decrease, further improving the mass transfer of water and gas and enhancing the treatment effect of the mixing and dissolution reaction.

[0052] Furthermore, the ozone generating unit 3 includes an ozone generator and a gas compressor connected in sequence. The gas compressor is connected to the air inlet 2-1-2 of the gas-liquid enhanced perturbation pressurized dissolved gas device. The ozone generator is used to produce ozone gas of a certain concentration, and the gas compressor is used to pressurize the produced ozone gas to meet the dissolved gas inlet pressure requirements of the gas-liquid enhanced perturbation pressurized dissolved gas device. The oxygen generating unit 4 includes an oxygen generator or an oxygen source, which can directly supply oxygen or use an oxygen generator to convert air into oxygen for use by the ozone generator.

[0053] Furthermore, the exhaust gas drying, decomposition and storage unit 5 includes a dryer, an ozone decomposition reactor and an oxygen storage tank connected in sequence. The dryer is connected to the exhaust gas emission port of the heterogeneous ozone catalytic oxidation unit 1, and the oxygen storage tank is connected to the ozone generator of the ozone generation unit 3 to collect the exhaust gas for recycling.

[0054] This invention relates to an ozone catalytic oxidation treatment method based on gas-liquid enhanced perturbation pressurized dissolved gas, comprising the following steps:

[0055] S1: The organic wastewater to be treated enters the heterogeneous ozone catalytic oxidation unit 1. After being uniformly distributed with water and gas in the buffer zone, it rises into the catalytic oxidation packing zone. The heterogeneous catalyst is made by impregnation and calcination with modified active alumina as the carrier and transition metal oxides of Mn, Cu, and Ce as the active components. It has a large specific surface area, many active sites, good mechanical properties, and good catalytic effect. In this zone, organic matter, ozone, and heterogeneous catalyst interact to undergo adsorption, surface coordination complexation, and hydroxyl radical oxidation, consuming ozone and decomposing organic matter, thus initially degrading the organic pollutants in the organic wastewater to be treated. Then, a part of the wastewater is returned to the gas-liquid enhanced disturbance pressurized dissolved gas unit 2 for secondary removal of pollutants. The remaining part is oxidized again by ozone dissolved in the liquid phase in the clear water zone and flows out of the heterogeneous ozone catalytic oxidation unit for discharge or post-treatment. The remaining undissolved oxygen and a small amount of unreacted ozone gas are collected and sent to the tail gas drying, decomposition, and storage unit 5.

[0056] S2: The organic wastewater that has undergone preliminary treatment in step S1 is transported through a return pipeline and pressurized to 0.1-0.5 MPa by a dissolved gas pressurization pump before entering the gas-liquid enhanced disturbance pressurized dissolved gas device.

[0057] S3: The exhaust gas collected in step S1 enters the exhaust gas drying, decomposition and storage unit 5. The dryer removes the moisture, and then the porous silica-alumina ozone decomposition catalyst filled in the ozone decomposition reactor decomposes the unreacted ozone into oxygen. The oxygen is then temporarily stored and stabilized in the oxygen storage tank and used as an oxygen source for ozone production and reuse.

[0058] S4: Oxygen generation unit 4 can be directly supplied by an oxygen source or obtain oxygen for later use through an oxygen generation mechanism; the ozone generator in ozone generation unit 3 uses the oxygen recovered in step S3 and the oxygen produced by the oxygen generation unit to generate ozone, which is then pressurized to 0.1-0.5 MPa by a gas compressor and sent to the gas-liquid enhanced disturbance pressurized dissolved gas device.

[0059] S5: The high-pressure and high-speed water and gas generated in steps S2 and S4 are uniformly distributed by the high-frequency cutting of the high-resistance water distribution pipe 2-2-1 and the air distribution wire pipe 2-2-2 of the gas-liquid enhanced perturbation pressurized dissolved air device, forming a uniformly dispersed gas-liquid mixture. This makes the water and gas velocities tend to be the same at the same cross section of the device, and then they rise at the same velocity and enter the labyrinth-type gas-liquid perturbation device 2-2-3. After being blocked and cut by the multiple layers of alternating longitudinal and transverse flow-reflecting cones, the water and gas flow states change drastically, forming a high-speed reversal motion and increasing the degree of turbulence, which allows the two to quickly merge. At the same time, the merging improves the gas-liquid mass transfer efficiency, forming a highly mixed gas-liquid mixture, which then enters the heterogeneous ozone catalytic oxidation unit 1 through the dissolved air water pipeline. Due to the high pressure, high flow rate, and high-frequency gas-liquid enhanced perturbation effect, ozone is fully dissolved, mass transfer efficiency is improved, and ozone utilization and overall oxidation effect are enhanced.

[0060] S6: The highly mixed gas-liquid mixture generated in step S5 enters the dissolved air water branch pipe in the buffer zone of the heterogeneous ozone catalytic oxidation unit 1 through the dissolved air water pipeline, and is evenly distributed by the dissolved air water distributor, which increases the contact area and contact time between the dissolved air water and organic pollutants. The catalytic oxidation packing generates hydroxyl radicals to further enhance the removal of residual organic matter.

[0061] Preferably, the amount of oxygen produced by oxygen-generating unit 4 in step S3 is calculated using the following formula:

[0062]

[0063] In the formula:

[0064] Q0—Oxygen production capacity of the oxygen generation unit, m 3 / h;

[0065] Q—Inlet flow rate, m 3 / h;

[0066] Q1—Exhaust gas flow rate, m 3 / h;

[0067] S0—Influent COD concentration, mg / L;

[0068] S e —Effluent COD concentration, mg / L;

[0069] C0—Ozone concentration at the ozone generator outlet, mg / L;

[0070] C1 — Ozone concentration in the reaction liquid phase, mg / L;

[0071] C2—Ozone concentration in exhaust gas, mg / L;

[0072] a—Ozone consumption per unit of COD removed, ranging from 1 to 5;

[0073] b—reflux ratio, ranging from 0.1 to 0.5;

[0074] k1—First correction factor, which is 0.6 to 0.8 when Se < 20 mg / L; 1.2 to 1.5 when Se ≥ 30 mg / L; and 1 when 20 mg / L ≤ Se < 30 mg / L.

[0075] k2—Second correction coefficient, taken as 1.1 to 1.3 when S0 < 80 mg / L; taken as 0.6 to 0.8 when S0 ≥ 100 mg / L; and taken as 1 when 80 mg / L ≤ Se < 100 mg / L.

[0076] Example 1

[0077] 1. The circulating water makeup water of a thermal power plant in northern China is municipal reclaimed water, and the effluent meets the Class A standard, with a COD concentration of 30-50 mg / L. A new circulating water wastewater treatment system was constructed as part of a deep water-saving renovation project. The average COD concentration in the wastewater is 80-130 mg / L. An ozone catalytic oxidation treatment system based on gas-liquid enhanced disturbance pressurized dissolved gas, as described in this invention, was added between the filtration and ultrafiltration processes. The system is designed to treat 220 m³ of water. 3 The catalytic reaction tower has a hydraulic residence time of 30 min, uses a 3-5 mm diameter Mn / Cu-Al2O3 catalyst, and employs an oxygen generator to obtain oxygen. Oxygen is also recovered from the tail gas. The gas-liquid enhanced turbulence pressurized dissolved air device has an inlet air and water pressure of 0.3 MPa, a residence time of 3 min, a height-to-diameter ratio of 4:1, 1 mm diameter orifices in the water and gas distribution pipes, a spacing of 100 mm, and a wire gap of 0.2 mm. The labyrinthine gas-liquid turbulence device has 10 layers of flow-around reflective cones, each with a 90° apex angle, a horizontal spacing of 1 cm between adjacent cones, a base width of 2 cm, and a distance of 10 cm between adjacent layers. The influent and effluent water quality indicators are shown in Table 1 below.

[0078] Table 1. Water quality indicators of influent and effluent from the ozone catalytic oxidation treatment system based on gas-liquid enhanced perturbation and pressurized dissolved gas.

[0079] Serial Number project numerical values 1 Influent COD concentration (mg / L) 80～130 2 Effluent COD concentration (mg / L) 25～33 3 COD removal rate (%) 68.7～74.5 4 <![CDATA[O3 / COD]]> 1.5 5 <![CDATA[O2 production amount (m 3 / ton of water)]]> 0.09 6 Operating cost (RMB / ton of water) 0.59

[0080] 2. Based on the aforementioned formula, accurately calculating and controlling the oxygen production rate can reduce energy consumption: Q = 220m 3 / h, Q1=177m 3 / h, S0=80mg / L, S e =20mg / L, C0=140mg / L, C1=100mg / L, C2=15mg / L, a=2, b=0.3, k1=1, k2=1. Oxygen production capacity of the oxygen generation unit: Q0=20.4m³ / L. 3 / h.

[0081] The traditional ozone catalytic oxidation process system was adopted, which does not perform tail gas recovery. The oxygen demand of the ozone generator is entirely obtained from the oxygen generator, and there is no reaction liquid reflux. The low-pressure ozone and oxygen mixture generated by the ozone generator is released as dissolved gas through the aeration plate at the bottom of the catalytic tower. Compared with Example 1 of the present invention, under the same operating parameters such as influent water quality and quantity, the same catalyst type and filling amount, and the same reaction time, ozone dosage and dosage, the COD concentration of the influent and effluent was monitored, as shown in Table 2.

[0082] Table 2. Water quality indicators of influent and effluent from traditional ozone catalytic oxidation treatment systems

[0083] Serial Number project numerical values 1 Influent COD concentration (mg / L) 80～120 2 Effluent COD concentration (mg / L) 33.6～57.6 3 COD removal rate (%) 52～58 4 <![CDATA[O3 / COD]]> 2.2 5 <![CDATA[O2 production amount (m 3 / ton of water)]]> 0.85 6 Operating cost (RMB / ton of water) 0.86

[0084] As shown in Tables 1 and 2, the ozone catalytic oxidation treatment system based on gas-liquid enhanced perturbation and pressurized dissolved gas of this invention improves the average COD removal rate by 16.6% compared with the traditional ozone catalytic oxidation treatment process system, reduces the ozone dosage by 32%, reduces the O2 production by 89%, and reduces the operating cost by 0.27 yuan / ton of water. This invention has better treatment effect and economic benefits.

[0085] This invention employs a pressurized dissolved air method that regulates water and air pressure to adjust the partial pressure of ozone in water, thereby increasing ozone solubility. Simultaneously, the pressurized mixed fluid is regulated by a high-resistance water and air distribution system and a labyrinth-type ozone high-frequency disturbance device, improving the uniformity of water and air distribution, enhancing turbulence, and increasing mixing and mass transfer efficiency. The mixed liquid is refluxed, allowing dissolved ozone in the liquid phase to continue participating in the reaction, collectively improving ozone utilization and reducing ozone dosage. This invention also collects and converts tail gas for recycling as an oxygen source. Furthermore, it proposes a precise oxygen production method based on the coordinated control of multiple parameters, including influent and effluent water quality, quantity, and ozone concentration. This method allows for precise and automatic control of oxygen production based on real-time calculations by a host computer using online water quality, quantity, and ozone concentration data, achieving precise oxygen production, improving oxygen utilization, and saving oxygen consumption. This invention integrates ozone catalytic oxidation technology into a system structure and optimizes the process, saving ozone and oxygen consumption, reducing system operating energy consumption, and improving treatment effect. It can be well applied to organic wastewater treatment scenarios with drastic fluctuations in water quality and quantity, such as power plant circulating water discharge, circulating water makeup water, and desulfurization wastewater.

[0086] The above description only illustrates the preferred embodiments of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. All modifications made within the scope of the independent claims of this invention are also within the scope of protection of this invention.

[0087] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

Claims

1. An ozone catalytic oxidation treatment system based on gas-liquid enhanced perturbation pressurized dissolved gas, characterized in that, It includes a heterogeneous ozone catalytic oxidation unit (1), a gas-liquid enhanced disturbance pressurized dissolved air unit (2), an ozone generation unit (3), an oxygen generation unit (4), and a tail gas drying, decomposition and storage unit (5); Among them, the oxygen generation unit (4) is connected to the ozone generation unit (3), the ozone generation unit (3) is connected to the gas-liquid enhanced disturbance pressurized dissolved air unit (2), the gas-liquid enhanced disturbance pressurized dissolved air unit (2) is connected to the heterogeneous ozone catalytic oxidation unit (1), the heterogeneous ozone catalytic oxidation unit (1) is connected to the tail gas drying, decomposition and storage unit (5), and the tail gas drying, decomposition and storage unit (5) is connected to the ozone generation unit (3); The gas-liquid enhanced disturbance pressurized dissolved air unit (2) includes a gas-liquid enhanced disturbance pressurized dissolved air device, and the gas-liquid enhanced disturbance pressurized dissolved air device includes a housing (2-1) and a water distribution pipe (2-2-1), a gas distribution pipe (2-2-2), and a labyrinth gas-liquid disturbance device (2-2-3) arranged inside the housing (2-1); The water distribution pipe (2-2-1) and the gas distribution pipe (2-2-2) adopt a cross-shaped water and gas distribution main and branch pipes, which are horizontally arranged, and the ends of the main pipe and the branch pipes are blocked; the cross-shaped water and gas distribution main and branch pipes include a water distribution branch pipe (2-2-1-1) and a gas distribution branch pipe (2-2-2-1). The water distribution branch pipe (2-2-1-1) and the gas distribution branch pipe (2-2-2-1) are double-layer wire-wound pipes, including an inner layer circular pipe and an outer layer wire-wound pipe. The inner layer circular pipe is alternately arranged with φ1-2mm jet circular air holes downward at a 45° horizontal angle every 100-200mm along the length direction on both sides. The outer layer wire-wound pipe is wrapped around the inner layer circular pipe along the length direction. The diameter of the outer layer wire-wound pipe is 5-10mm larger than the diameter of the inner layer circular pipe, and the adjacent wire spacing of the outer layer wire-wound pipe is 0.2-0.5mm; The labyrinth gas-liquid disturbance device (2-2-3) is composed of flow-around reflection cones (2-2-3-1) arranged horizontally and alternately in the vertical and horizontal directions along the height direction; the labyrinth gas-liquid disturbance device flow-around reflection cones (2-2-3-1) are arranged in 4-10 layers, the apex angle of each layer of reflection cone is 45-90°, the horizontal distance between adjacent reflection cones is 1-2cm, the bottom width of the reflection cone is 2-5 times the distance between the reflection cones, and the distance between adjacent two layers of reflection cones is 5-15cm.

2. The ozone catalytic oxidation treatment system based on gas-liquid enhanced perturbation pressurized dissolved gas according to claim 1, characterized in that, The heterogeneous ozone catalytic oxidation unit (1) includes a heterogeneous ozone catalytic oxidation tower, and the heterogeneous ozone catalytic oxidation tower includes a catalytic oxidation tower housing. A catalytic oxidation filler is arranged inside the catalytic oxidation tower housing. A clear water area is provided above the catalytic oxidation filler, and a tail gas discharge port is provided at the top of the clear water area. A buffer area is provided below the catalytic oxidation tower filler, and a plurality of dissolved air water distributors are evenly arranged at the bottom of the buffer area.

3. The ozone catalytic oxidation treatment system based on gas-liquid enhanced perturbation pressurized dissolved gas according to claim 2, characterized in that, A dissolved air water interface is provided at the bottom of the catalytic oxidation tower housing, and a reflux port is provided above the clear water area on the catalytic oxidation tower housing; each dissolved air water distributor is respectively connected to a dissolved air water main pipe, presenting a cross-shaped structure; the dissolved air water main pipe is connected to the dissolved air water interface on the catalytic oxidation tower housing, and the reflux port is connected to the gas-liquid enhanced disturbance pressurized dissolved air unit (2).

4. The ozone catalytic oxidation treatment system based on gas-liquid enhanced perturbation pressurized dissolved gas according to claim 3, characterized in that, The gas-liquid enhanced perturbation pressurized dissolved gas unit (2) includes a return pipeline, a dissolved gas pressurization pump, a gas-liquid enhanced perturbation pressurized dissolved gas device and a dissolved gas water pipeline connected in sequence. The first end of the return pipeline is connected to the return port of the heterogeneous ozone catalytic oxidation unit, and the end of the dissolved gas water pipeline is connected to the dissolved gas water interface.

5. The ozone catalytic oxidation treatment system based on gas-liquid enhanced perturbation pressurized dissolved gas according to claim 4, characterized in that, The outer shell (2-1) of the gas-liquid enhanced disturbance pressurized dissolved gas device is cylindrical with a height-to-diameter ratio of 4:1 to 5:

1. The lower end of the outer shell (2-1) is provided with a water inlet (2-1-1), the upper end of the water inlet (2-1-1) is provided with an air inlet (2-1-2), the upper end of the outer shell (2-1) is provided with a water outlet (2-1-3), the water inlet (2-1-1) is connected to the outlet of the dissolved gas pressurization pump, the water outlet (2-1-3) is connected to the beginning of the dissolved gas water pipeline, and the air inlet is connected to the outlet of the ozone generating unit (3).

6. The ozone catalytic oxidation treatment system based on gas-liquid enhanced perturbation pressurized dissolved gas according to claim 1, characterized in that, The first end of the water distribution pipe (2-2-1) is connected to the water inlet (2-1-1), the first end of the air distribution pipe (2-2-2) is connected to the air inlet (2-1-2), and the labyrinth-type gas-liquid disturbance device (2-2-3) is located above the air inlet (2-1-2).

7. The ozone catalytic oxidation treatment system based on gas-liquid enhanced perturbation pressurized dissolved gas according to claim 1, characterized in that, The ozone generating unit (3) includes an ozone generator and a gas compressor connected in sequence, and the gas compressor is connected to a gas-liquid enhanced disturbance pressurized dissolved gas device; The exhaust gas drying, decomposition and storage unit (5) includes a dryer, an ozone decomposition reactor and an oxygen storage tank connected in sequence. The dryer is connected to the heterogeneous ozone catalytic oxidation unit (1) and the oxygen storage tank is connected to the ozone generation unit (3).

8. A method for ozone catalytic oxidation based on gas-liquid enhanced perturbation pressurized dissolved gas according to any one of claims 1-7, characterized in that, Includes the following steps: The organic wastewater to be treated enters the heterogeneous ozone catalytic oxidation unit (1) to initially degrade the organic pollutants in the organic wastewater. Then, a portion of the wastewater is returned to the gas-liquid enhanced disturbance pressurized dissolved gas unit (2) to form high pressure and high speed water gas. The remaining wastewater flows out of the heterogeneous ozone catalytic oxidation unit (1). The remaining undissolved oxygen and unreacted ozone gas enter the tail gas drying decomposition and storage unit (5). The unreacted ozone gas is converted into oxygen. The oxygen in the tail gas drying decomposition and storage unit (5) and the oxygen in the oxygen generation unit (4) enter the ozone generation unit (3) to form high pressure ozone. After high-pressure, high-speed water and gas are cut and evenly distributed with high-pressure ozone, a uniformly dispersed gas-liquid mixture is formed. Then, it rises at the same flow rate and enters the labyrinth-type gas-liquid disturbance device (2-2-3). After being blocked and cut by the multi-layered longitudinal and transverse alternating flow reflection cones, the water and gas flow state changes drastically, forming a high-speed reversal motion. The degree of turbulence increases, causing the water and gas to quickly dissolve and form a highly mixed gas-liquid mixture. Then, it enters the heterogeneous ozone catalytic oxidation unit (1) to remove the remaining organic matter.

9. The method according to claim 8, characterized in that, The oxygen production capacity of the oxygen generation unit is calculated using the following formula: In the formula: Q0— oxygen production unit oxygen production amount, m 3 / h; —Inlet flow rate, m 3 / h; Q1—Exhaust gas flow rate, m 3 / h; S0—Influent COD concentration, mg / L; S e —Effluent COD concentration, mg / L; C0—Ozone concentration at the ozone generator outlet, mg / L; C1 — Ozone concentration in the reaction liquid phase, mg / L; C2—Ozone concentration in exhaust gas, mg / L; a—Ozone consumption per unit of COD removed; b—reflux ratio; k1—First correction factor; k2—Second correction coefficient.

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