An advanced oxidation device

Abstract

The application discloses a novel advanced oxidation device which comprises an outer shell, a gas-liquid mixing chamber, an ultrasonic atomization disc, an air inlet hole, a water inlet hole, an ozone generator, a UV reaction disc tube and the like. Through ultrasonic catalysis and ultraviolet light catalysis, O3 is excited to generate a large amount of higher oxidizing ·OH, the mixing degree and turbulence intensity of ozone and sewage are improved, the mass transfer coefficient is increased, the mass transfer rate of ozone is improved, four-stage oxidation reactions are carried out in one reactor, and thus the ozone oxidation efficiency and effect are greatly improved, the pollutants in the wastewater are subjected to intensified oxidation, and thus the pollutants in the wastewater are degraded and removed.

Description

Technical Field

[0001] This invention relates to the field of advanced oxidation technology, specifically to an advanced oxidation apparatus. Background Technology

[0002] Ozone oxidation began to be used in the 1950s for the treatment of urban sewage and industrial wastewater. Its technological advantages include: 1. Strong oxidation capacity, with significant effects on deodorization, decolorization, sterilization, and removal of both organic and inorganic matter, achieving rapid mineralization of organic matter in a short time; 2. The ozone oxidation reaction completely degrades organic matter into carbon dioxide and water, without producing secondary pollution. The air and electricity used for ozone do not need to be stored or transported, and operation and maintenance are relatively simple.

[0003] The ozone generator alone consumes a lot of energy, the oxidation intensity of O3 is weaker than that of ·OH, gas-liquid mixing is difficult in water, the reaction time is long and it is usually over-added, resulting in high treatment costs. In addition, its ozone oxidation reaction is selective and the oxidation effect on some halogenated hydrocarbons and pesticides is relatively poor. Summary of the Invention

[0004] The problem this invention aims to solve is to address the shortcomings of existing technologies by proposing an innovative process that can convert a large amount of O3 into more efficient ·OH, resulting in a shorter processing time and better oxidation effect; it eliminates the need for additional chemical agents or catalysts, reducing secondary pollution and maintenance complexity. This invention combines ozone oxidation, ultrasonic oxidation, and ultraviolet / ozone oxidation processes, allowing the O3 introduced into the reactor to be excited by ultrasound and UV, reacting with H2O to generate a large amount of highly oxidizing ·OH, thereby oxidizing and degrading pollutants in wastewater and achieving the effect of removing pollutants from the wastewater.

[0005] To solve the above problems, the present invention adopts the following solution: an advanced oxidation device, characterized in that it includes an outer shell, the outer shell having a conical structure; a gas-liquid mixing chamber is provided at the top of the outer shell, an ultrasonic atomizing disc is provided in the gas-liquid mixing chamber, and an annular groove is left between the ultrasonic atomizing disc and the gas-liquid mixing chamber, an air inlet and a water inlet are provided at intervals in the annular groove, the air inlet being connected to an ozone generator; a spiral UV reaction coil is provided inside the outer shell, a connecting hole communicating with the UV reaction coil is provided on the side wall of the gas-liquid mixing chamber, and a water outlet is provided at the bottom of the UV reaction coil; an air outlet is provided at the top of the outer shell, and a gas-liquid separation inclined plate is provided inside the air outlet.

[0006] Furthermore, the UV reaction coil is equipped with a UV light strip for irradiating the mixed gas and liquid with ultraviolet light.

[0007] Furthermore, a conical hollow cavity is provided inside the outer shell above the gas-liquid mixing chamber; the UV reaction coil is composed of the inner wall of the outer shell, the outer wall of the hollow cavity, and a spiral partition.

[0008] Furthermore, the ultrasonic atomizing disk is provided with vibrating diaphragms of at least one ultrasonic atomizer.

[0009] There are two reaction pathways in ozone catalytic oxidation: (1) Ozone reacts directly with organic matter. It is selective and generally attacks organic matter with double bonds, and is more effective for aromatic and unsaturated aliphatic hydrocarbon organic compounds. (2) Ozone (O3) catalytic oxidation produces intermediate products such as hydroxyl radicals (·OH) with stronger oxidizing power, which then undergo a relatively non-selective oxidative decomposition reaction with organic pollutants.

[0010] After ultrasonic atomization, the wastewater droplets appear as tiny floating particles of about 5 micrometers. In an environment filled with high concentrations of ozone, the gas and liquid mix, increasing the contact area between ozone and water, which can improve the mass transfer rate and oxidation efficiency of ozone.

[0011] Ultrasonic enhancement of ozone oxidation manifests in two main aspects: ① Promoting ozone decomposition; under ultrasonic waves, ozone decomposes and reacts with water to produce more and more reactive free radicals such as ·OH; ② Increasing the mass transfer rate constant; on the one hand, ultrasound can transform ozone bubbles into "microbubbles," increasing the contact area between ozone and water, i.e., increasing the surface area. On the other hand, by atomizing it into micron-sized droplets, it increases the mixing degree and turbulence intensity of gas and water, reduces the liquid film thickness, decreases resistance, and increases the mass transfer coefficient, thereby improving the mass transfer rate of ozone.

[0012] There are currently two main viewpoints regarding the synergistic mechanism of ozone and ultraviolet (UV) radiation. One viewpoint is that ozone first decomposes into oxygen atoms under UV radiation, and the free oxygen atoms (·O) then react with water to generate hydroxyl radicals (·OH) with a higher oxidation potential. The other viewpoint is that ozone first reacts with water under UV irradiation to generate hydrogen peroxide, which further decomposes to generate hydroxyl radicals (·OH). This approach overcomes the slow reaction rate and high selectivity of ozone (O3) with organic matter, thus improving the oxidation effect. The reaction mechanism is as follows:

[0013] O3 + H2O + UV → H2O2 + O2 (2-1)

[0014] H2O2 + UV → 2·OH (2-2)

[0015] H2O2↔H2O - +H + (2-3)

[0016] O3+H2O - →O3· - +HO2· (2-4)

[0017] HO2·→O2· - +H + (2-5)

[0018] O3+O2· - →O3· - +O2 (2-6)

[0019] O3· - +H + ↔HO3· (2-7).

[0020] The technical effects of this invention are as follows:

[0021] 1) This invention utilizes the ultrasonic cavitation effect to promote the decomposition of ozone in water. Under the action of ultrasound, ozone decomposes and reacts with water to produce more and more active free radicals such as ·OH, thereby improving chemical oxidation performance.

[0022] 2) This invention utilizes ultrasound (US) to transform ozone bubbles into "microbubbles," increasing the contact area between ozone and water, i.e., increasing the surface area. On the other hand, the cavitation effect of bubble collapse generates microscopic supercritical water, producing a thermal effect that, to a certain extent, pyrolyzes pollutants in the water.

[0023] 3) This invention utilizes ultrasonic atomization combined with ultraviolet excitation. The atomized wastewater droplets appear as micron-sized floating particles, suspended in the ozone environment. This increases the mixing degree and turbulence intensity of ozone and water, reduces resistance, and increases the mass transfer coefficient, thereby improving the ozone mass transfer rate and thus enhancing the ozone oxidation effect. Ozone first decomposes into oxygen atoms under ultraviolet light. The free oxygen atoms (·O) then react with water to generate hydroxyl radicals (·OH) with a higher oxidation potential, thereby improving chemical oxidation performance.

[0024] 4) This invention utilizes a variable-diameter spiral coil reactor, which causes the atomized droplets to continuously collide and coarsen during centrifugal acceleration. After converging, they collide with the sidewalls and top inclined plate before flowing downwards. The surface comes into contact with ozone and is irradiated with ultraviolet light, resulting in a secondary catalytic oxidation reaction. This method offers higher utilization efficiency of ozone and ultraviolet light and facilitates subsequent treatment of the collected water. Compared to a straight-tube reactor with a subsequent gas-liquid separator, this method is more effective and requires less space. The variable-diameter spiral coil reactor has a smaller pipe diameter closer to the outlet, resulting in a faster flow rate. This further enhances the mixing degree and turbulence intensity of ozone, hydroxyl radicals (·OH), and other components with water, thereby improving the purification effect. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the process.

[0026] Figure 2 A frontal view of the advanced oxidation unit.

[0027] Figure 3 A frontal cross-sectional view of the advanced oxidation unit.

[0028] Figure 4 This is a 3D cross-sectional view of the interior of an advanced oxidation unit.

[0029] Figure 5 The COD removal rates are for Examples 1-4.

[0030] Among them, 1. gas-liquid mixing chamber, 2. water outlet, 3. outer shell, 4. air outlet, 5. gas-liquid separation inclined plate, 6. hollow cavity, 7. UV light strip, 8. UV reaction coil, 9. connecting hole, 10. ultrasonic atomizing plate, 11. water inlet, 12. air inlet, 13. ultrasonic atomizer vibrating diaphragm. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings.

[0032] Example: Figure 2 , Figure 4 As shown, an advanced oxidation device includes a conical outer shell 3. The top of the outer shell 3 has a gas-liquid mixing chamber 1, within which an ultrasonic atomizing disc 10 is installed. An annular groove is formed between the ultrasonic atomizing disc 10 and the gas-liquid mixing chamber 1, with an air inlet 12 and a water inlet 11 spaced apart within the groove. The air inlet 12 is connected to an ozone generator. A spiral UV reaction coil 8 is installed inside the outer shell 3. A connecting hole 9, communicating with the UV reaction coil 8, is located on the side wall of the gas-liquid mixing chamber 1. A water outlet 2 is located at the bottom of the UV reaction coil 8. An air outlet 4 is located at the top of the outer shell 3, within which a gas-liquid separation inclined plate 5 is installed. A UV light strip 7 is installed inside the UV reaction coil 8 for irradiating the mixed gas and liquid with ultraviolet light. A conical hollow cavity 6 is located above the gas-liquid mixing chamber 1 inside the outer shell 3. The UV reaction coil 8 is composed of the inner wall of the outer shell 3, the outer wall of the hollow cavity 6, and a spiral partition. The ultrasonic atomizing disc 10 is equipped with 6 ultrasonic atomizer vibrating diaphragms 13.

[0033] In the gas-liquid mixing chamber 1 at the lower end of the reactor, wastewater is introduced through the annularly spaced water inlet 11 and ozone gas is introduced through the air inlet 12. The mixture is then overflowed into the middle ultrasonic atomizing disk 10 (the liquid level in the disk can be controlled by the water inlet speed to ensure atomization efficiency). The ultrasonic atomizer diaphragm 13, which is evenly distributed in the disk, vibrates at high frequency, which can transform ozone bubbles into "microbubbles", increasing the contact area between ozone and water, that is, increasing the surface area and improving mass transfer efficiency. On the other hand, cavitation produces microscopic supercritical water, which generates a thermal effect to degrade pollutants in the water. Simultaneously, ultrasonic vibration can atomize the waste liquid, generating micron-sized droplets, increasing the ozone contact area. The continuously introduced ozone gas increases the gas pressure in the gas-liquid mixing chamber 1, pushing the droplets from the connecting hole 9 into the UV reaction coil 7. The UV reaction coil 7 spirals upward around the closed hollow cavity 6, and the waste liquid droplets and ozone gas mix in the inner cavity of the coil. The UV light strip 8 is attached to the inner cavity of the reaction coil, irradiating the mixed gas and liquid with ultraviolet light. Under the action of ultraviolet light, the ozone first decomposes into free oxygen atoms (·O), and the free oxygen atoms (·O) then react with water to generate hydroxyl radicals (·OH) with higher oxidation potential, thereby improving the chemical oxidation performance. Simultaneously, as the inner diameter of the coil continues to shrink upwards, the flow velocity inside the tube continuously increases. The droplets accelerate and spiral upwards inside the tube, gradually colliding and condensing into larger droplets. At the top, they are intercepted by the gas-liquid separation inclined plate 5 and drip into the inner cavity of the UV reaction coil 7, flowing downwards and contacting the O3 surface while being irradiated with ultraviolet light. A secondary UV + O3 catalytic oxidation reaction occurs, and finally, the gas is discharged from the outlet 2. The remaining gas bypasses the gas-liquid separation inclined plate 5 and is discharged from the gas outlet 4, completing the entire contact reaction process.

[0034] Working principle: This invention combines ozone, ultrasonic catalysis, and ultraviolet photocatalytic oxidation technologies. Wastewater undergoes O3 mixing and oxidation in the annular water tank of the gas-liquid mixing chamber 1, which is the first stage of oxidation. After the waste liquid is mixed with O3, it overflows into the ultrasonic atomizing disk 10, where US + O3 oxidation occurs, which is the second stage of oxidation. The ultrasonically atomized waste liquid forms droplets that mix with ozone and are then irradiated with ultraviolet light by the UV light strip attached to the inner cavity of the UV reaction disk 7, resulting in UV + O3 catalytic oxidation, which is the third stage of oxidation. The upward-colliding and converging liquid flows downward in the reactor, comes into contact with the ozone surface, and is irradiated with ultraviolet light, resulting in UV + O3 catalytic oxidation, which is the fourth stage of oxidation. The four-stage oxidation process, which combines ozone, ultrasonic catalytic oxidation, and ultraviolet photocatalytic oxidation technologies, simplifies and integrates the reactor structure without the use of a catalyst. By stimulating the ozone oxidation reaction with ultrasound and ultraviolet light, the oxidation contact area is increased, and the mass transfer efficiency is improved. At the same time, a large amount of O3 is converted into ·OH, which has stronger oxidizing power, thereby improving the ozone oxidation efficiency and effect, reducing production and maintenance costs, and enabling continuous and efficient oxidation and degradation of pollutants in water.

[0035] Example 1: Treating 3.5 liters of landfill leachate NF concentrate by simply introducing O3 into the reactor based on the above technical solution, and running for 180 minutes.

[0036] Example 2: To treat 3.5 liters of landfill leachate NF concentrate, O3 was introduced into the reactor based on the above technical solution, and the ultrasonic atomizer was turned on and run for 180 minutes.

[0037] Example 3: Treatment of 3.5 liters of landfill leachate NF concentrate. Based on the above technical solution, O3 was introduced into the reactor, and the ultrasonic atomizer and ultraviolet lamp were turned on. The reactor structure was a glass straight tube, and the operation lasted for 180 minutes.

[0038] Example 4: To treat 3.5 liters of landfill leachate NF concentrate, O3 was introduced into the reactor based on the above technical solution, and the ultrasonic atomizer and ultraviolet lamp were turned on. The reactor structure was as described in the patent specification, and the reactor was run for 180 minutes.

[0039] COD removal rate after 3 hours Example 1 21.93% Example 2 37.67% Example 3 53.47% Example 4 67.32%

[0040] This uses a fixed-power ultrasonic generator and a fixed ozone intake concentration and flow rate. If the process parameters are adjusted and refined according to the water quality and quantity, the COD degradation efficiency can be further improved.

Claims

1. An advanced oxidation apparatus, characterized in that, The device includes an outer shell (3), the top of which is provided with a gas-liquid mixing chamber (1). An ultrasonic atomizing disc (10) is provided inside the gas-liquid mixing chamber (1), and an annular groove is left between the ultrasonic atomizing disc (10) and the gas-liquid mixing chamber (1). An air inlet (12) and a water inlet (11) are spaced apart within the annular groove. The air inlet (12) is connected to an ozone generator. The outer shell (3) is provided with a spiral-structured UV reaction disc (8), and the side wall of the gas-liquid mixing chamber (1) is provided with a connection to the UV reaction disc. The tube (8) is connected to the connecting hole (9), and the bottom of the UV reaction coil (8) is provided with a water outlet (2); the top of the outer shell (3) is provided with an air outlet (4), and the air outlet (4) is provided with a gas-liquid separation inclined plate (5); the hollow cavity (6) with a conical structure is provided in the outer shell (3) above the gas-liquid mixing chamber (1); the UV reaction coil (8) is composed of the inner wall of the outer shell (3), the outer wall of the hollow cavity (6) and the spiral partition; the outer shell (3) has a conical structure, forming a variable diameter spiral coil-shaped reactor.

2. The advanced oxidation apparatus according to claim 1, characterized in that, The UV reaction coil (8) is equipped with a UV light strip (7) for irradiating the mixed gas and liquid with ultraviolet light.

3. The advanced oxidation apparatus according to claim 1, characterized in that, The ultrasonic atomizing disc (10) is provided with at least three ultrasonic atomizer vibrating diaphragms (13).

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