A sewage ozone catalytic oxidation treatment system and process

Abstract

The present invention belongs to the technical field of sewage treatment, and relates to a sewage ozone catalytic oxidation treatment system and process, comprising an air-water mixer, an oxygen separation device and a reactor connected in sequence, wherein the air-water mixer is a tubular structure, a water inlet pipe is located at one end of the tubular structure, and the side is tangent to the tubular structure, and the end of the air inlet pipe is located inside the water inlet pipe; the water inlet pipe is connected to a sewage source through a high-pressure pump, and the air inlet pipe is connected to an ozone generator; a sewage dosing device and a mixer are provided at the bottom of the reactor, and the sewage dosing device is provided above the mixer, and is connected to the sewage source; the mixer is connected to the oxygen separation device.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and in particular relates to a sewage ozone catalytic oxidation treatment system and process. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Ozone has strong oxidizing properties and can oxidize a variety of compounds. It has been widely used in wastewater treatment. However, when using ozone alone to treat wastewater, there are still major problems. It cannot completely oxidize and degrade organic matter at low doses and in a short period of time, and ozone has relatively limited oxidative degradation selectivity.

[0004] While ozone catalytic oxidation of wastewater can effectively address the aforementioned issues associated with ozone oxidation alone by combining the strong oxidizing properties of ozone with the catalytic and adsorption properties of catalysts, the existing technology struggles to achieve uniform mixing of ozone and wastewater, making it difficult to achieve satisfactory catalytic oxidation treatment results. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a sewage ozone catalytic oxidation treatment system and process.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] In a first aspect, the present invention provides a sewage ozone catalytic oxidation system, comprising a gas-water mixer, an oxygen separation device and a reactor connected in sequence, wherein:

[0008] The air-water mixer is a tubular structure, the water inlet pipe is located at one end of the tubular structure, and the side is tangent to the tubular structure, and the end of the air inlet pipe is located inside the water inlet pipe;

[0009] The water inlet pipe is connected to the sewage source through a high-pressure pump, and the air inlet pipe is connected to the ozone generator;

[0010] A sewage dosing device and a mixer are provided at the bottom of the reactor, and the sewage dosing device is provided above the mixer and is connected to a sewage source;

[0011] The mixer is connected to the oxygen separation device.

[0012] In a second aspect, the present invention provides a wastewater ozone catalytic oxidation process, comprising the following steps:

[0013] After the sewage and ozone are initially mixed, they are pumped into the tubular structure at high speed in a tangential direction by a high-pressure water pump. The violent turbulence in the tubular structure cuts the large ozone bubbles into fine bubbles, allowing the ozone to fully dissolve in the sewage to obtain an air-water mixture.

[0014] The gas-water mixture is transported to the oxygen separation device for oxygen separation, and the wastewater with oxygen removed is transported to the mixer at the bottom of the reactor for liquid distribution;

[0015] The sewage that has not been filled with ozone is pumped directly into the reactor and added above the mixer;

[0016] When the mixture of sewage and ozone flows through the catalyst layer in the reactor, the sewage is catalytically oxidized and degraded.

[0017] The beneficial effects achieved by one or more of the above embodiments of the present invention are as follows:

[0018] The air-water mixer is a tubular structure. The side of the water inlet pipe is tangent to the tubular structure, and the end of the air inlet pipe is located inside the water inlet pipe. Therefore, after the sewage and ozone are initially mixed, they enter the tubular structure at a high speed and tangentially under the pumping of the high-pressure water pump. The violent turbulence in the tubular structure cuts the large ozone bubbles into fine bubbles, which is more conducive to promoting the dissolution of ozone in water, improving the uniformity of mixing of ozone and sewage, and is more beneficial to improving the subsequent sewage treatment effect.

[0019] By pre-dissolving ozone in part of the sewage and then mixing it with the remaining sewage for catalytic oxidation, it is more conducive to promoting the uniform mixing of ozone and sewage, thereby effectively improving the utilization rate of ozone and the treatment effect on sewage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0021] Figure 1 is a schematic structural diagram of a sewage ozone catalytic oxidation treatment system according to one or more embodiments of the present invention;

[0022] Figure 2 is a schematic structural diagram of a gas-water mixer according to one or more embodiments of the present invention;

[0023] Figure 3 yes Figure 2 Cross-sectional view in the AA direction;

[0024] Figure 4 is a schematic structural diagram of a sewage dosing device according to one or more embodiments of the present invention;

[0025] Figure 5 Schematic diagram of the distribution of water distribution holes on a sewage branch pipe of a sewage dosing device according to one or more embodiments of the present invention;

[0026] Figure 6 is a schematic structural diagram of a mixer according to one or more embodiments of the present invention;

[0027] Figure 7 Schematic diagram of the relative positions of the mixing branch pipe and the mixing main pipe of the mixer according to one or more embodiments of the present invention;

[0028] Figure 8 is a schematic structural diagram of an oxygen separation device according to one or more embodiments of the present invention;

[0029] Figure 9 It is a schematic diagram of the top view structure of the oxygen separation device;

[0030] Figure 10 It is a structural schematic diagram of the baffle in the oxygen separation device.

[0031] In the figure: the distances or sizes between parts are exaggerated to show the positions of the parts, and the diagram is for illustration only;

[0032] Among them, 1-air inlet; 2-sewage inlet; 3-boosting pump; 4-first flow controller;

[0033] 5-gas-water mixer; 51-air inlet pipe; 52-water inlet pipe; 53-mixed liquid outlet;

[0034] 6-second one-way valve; 7-second flow controller;

[0035] 8- oxygen separation device; 81- air outlet; 82- mixed liquid inlet; 83- support leg; 84- water outlet; 85- swirl baffle; 86- umbrella cap;

[0036] 9-Sewage dosing device; 91-Sewage inlet; 92-Sewage main pipe; 93-Sewage branch pipe; 94-Water distribution hole;

[0037] 10-Ozone generator; 11-Reactor; 12-Gas purification device; 13-Tail gas destruction device; 14-Water outlet; 15-Third one-way valve; 16-Fourth one-way valve; 17-First one-way valve; 18-Discharge port;

[0038] 19-Mixer; 191-Mixing main pipe; 192-Mixing branch pipe; 193-Nozzle; 194-Mixer inlet. DETAILED DESCRIPTION

[0039] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0040] In a first aspect, the present invention provides a sewage ozone catalytic oxidation system, comprising a gas-water mixer, an oxygen separation device and a reactor connected in sequence, wherein:

[0041] The air-water mixer is a tubular structure, the water inlet pipe is located at one end of the tubular structure, and the side is tangent to the tubular structure, and the end of the air inlet pipe is located inside the water inlet pipe;

[0042] The water inlet pipe is connected to the sewage source through a high-pressure pump, and the air inlet pipe is connected to the ozone generator;

[0043] A sewage dosing device and a mixer are provided at the bottom of the reactor, and the sewage dosing device is provided above the mixer and is connected to a sewage source;

[0044] The mixer is connected to the oxygen separation device.

[0045] The oxygen separation device can separate the oxygen that is not dissolved in water. The separated oxygen is processed and then enters the ozone generator to be used as a gas source, thereby improving the oxygen utilization rate.

[0046] Dissolving ozone requires a certain amount of sewage. When the amount of sewage to be treated is large, only a part of the sewage is needed to dissolve ozone, and the rest of the sewage can directly enter the reactor. Therefore, it is necessary to mix the sewage with dissolved ozone with the sewage without dissolved ozone. The mixed sewage flows through the catalyst layer together for catalytic oxidation reaction.

[0047] Using a small amount of sewage to dissolve ozone can not only effectively improve the solubility of ozone, but also effectively save the volume of the gas-liquid mixer.

[0048] In some embodiments, the end of the air inlet pipe is located inside the water inlet pipe. In order to ensure the mixing effect, the end of the air inlet pipe is located inside the water inlet pipe. The angle between the air inlet pipe and the water inlet pipe is 85°-95°, and an elbow is set at the end of the air inlet pipe so that the gas flow direction and the water flow direction are the same.

[0049] Preferably, the mixed liquid outlet of the gas-water mixer is located on the opposite side of the water inlet pipe, so as to effectively prolong the gas-liquid mixing time and allow the gas and liquid to flow out after being evenly mixed inside the tubular structure.

[0050] Preferably, a first flow controller is provided between the gas-water mixer and the high-pressure pump.

[0051] Further preferably, a one-way valve is provided between the first flow controller and the high-pressure pump.

[0052] In some embodiments, the oxygen separation device is a vertical shell structure, the mixed liquid inlet is arranged tangentially along the side of the vertical shell, and a swirl baffle is arranged inside the shell. The swirl baffle rotates downward along the inner wall of the device in the oxygen separation device.

[0053] The mixed liquid inlet is arranged tangentially along the side of the vertical shell, so that the mixed liquid enters the rear vortex and continuously hits the vortex baffle during the vortex process, which is more conducive to promoting the separation of sewage and oxygen.

[0054] The mixed liquid carries some insoluble oxygen, which can be blocked by the baffle to promote the escape of insoluble oxygen in the mixed liquid. The liquid flows downward along the baffle, and the oxygen flows upward along the baffle.

[0055] Preferably, the gas outlet of the oxygen separation device is arranged at the top, the water outlet is arranged at the bottom, and a deflection element is arranged below the gas outlet.

[0056] The separated oxygen contains liquid droplets, and the liquid droplets entrained in the oxygen can be separated and removed by further blocking and deflecting the airflow using a deflection element.

[0057] Further preferably, the deflector element is an umbrella-shaped structure that completely covers the air outlet, with the tip of the umbrella facing the air outlet, so as to better improve the capture effect of the droplets.

[0058] In some embodiments, the sewage adding device includes a sewage main pipe and a plurality of sewage branch pipes connected to the sewage main pipe. Water distribution holes are provided on the sewage branch pipes, and the water distribution holes are arranged obliquely toward the bottom of the reactor.

[0059] The mixer is arranged below the sewage dosing device. The ozone-dissolved sewage introduced by the mixer is directly mixed with the sewage sprayed obliquely downward, which can promote the mixing of the two and improve the mixing uniformity of ozone in the sewage.

[0060] Preferably, the water distribution holes are arranged in different inclined directions to increase the degree of sewage disturbance at the bottom of the reactor.

[0061] Preferably, the mixing branch pipe of the mixer is arranged to be inclined upward relative to the horizontal direction, with an inclination angle of 5°-30°.

[0062] The mixture of sewage and ozone is sprayed upward at an angle, and the sewage is sprayed downward at an angle. Both can produce a greater shear force on each other, which is more conducive to uniform mixing of the two.

[0063] In some embodiments, a second flow controller and a second one-way valve are provided between the ozone generator and the gas-water mixer, and the second one-way valve is located between the second flow controller and the gas-water mixer.

[0064] The ratio of the values ​​of the first flow controller to the second flow controller is 1.2 to 3.0.

[0065] In some embodiments, a gas purification device is further included, and the gas purification device is connected to the oxygen separation device and the ozone generator respectively.

[0066] Preferably, a third one-way valve is provided on the connecting pipeline between the gas purification device and the oxygen separation device, so as to prevent oxygen from flowing from the oxygen separation device to the gas purification device and from flowing in the reverse direction.

[0067] Preferably, the gas purification device 12 includes a demister, an adsorption dryer, and a freeze dryer connected in sequence to remove water vapor from the oxygen.

[0068] In a second aspect, the present invention provides a wastewater ozone catalytic oxidation process, comprising the following steps:

[0069] After the sewage and ozone are initially mixed, they are pumped into the tubular structure at high speed in a tangential direction by a high-pressure water pump. The violent turbulence in the tubular structure cuts the large ozone bubbles into fine bubbles, allowing the ozone to fully dissolve in the sewage to obtain an air-water mixture.

[0070] The gas-water mixture is transported to the oxygen separation device for oxygen separation, and the wastewater with oxygen removed is transported to the mixer at the bottom of the reactor for liquid distribution;

[0071] The sewage that has not been filled with ozone is pumped directly into the reactor and added above the mixer;

[0072] When the mixture of sewage and ozone flows through the catalyst layer in the reactor, the sewage is catalytically oxidized and degraded.

[0073] In some embodiments, in the reactor, wastewater containing ozone is sprayed upward at an angle, and wastewater not filled with ozone is sprayed downward at an angle, and the two are shear-mixed with each other.

[0074] The following is a detailed description with reference to the accompanying drawings and specific embodiments.

[0075] like Figure 1 As shown, a sewage treatment ozone catalytic advanced oxidation system and process includes an air inlet 1, a sewage inlet 2, a booster pump 3, a first flow controller 4, a second flow controller 7, an air-water mixer 5, a second one-way valve 6, a third one-way valve 15, a fourth one-way valve 16 and a first one-way valve 17, an oxygen separation device 8, a sewage dosing device 9, a reactor 11, a mixer 19, a gas purification device 12, an exhaust gas destruction device 13, a water outlet 14, a discharge port 18 and an ozone generator 10.

[0076] The air inlet 1 is connected to the ozone generator 10, and the ozone generator 10 is connected to the flow controller 7, the second one-way valve 6, and the water-gas mixer 5 in sequence. The sewage inlet 2 is connected to the booster pump 3, and the booster pump 3 is connected to the one-way circulation valve 17, the flow controller 4, and the water-gas mixer 5 in sequence. The gas-water mixer 5 is further connected to the ozone separation device 8, the reactor 11, and the water outlet 14 in sequence. The oxygen separation device 8 is connected to the gas purification device 12 through the third one-way valve 15, the gas purification device 12 is connected to the air inlet 1, the reactor 11 is connected to the sewage inlet 2 through the fourth one-way valve 16, the reactor 11 is further connected to the tail gas destruction device 13, the tail gas destruction device 13 is connected to the discharge port 18, and the reactor 11 is provided with a sewage dosing device 9 and a mixer 19.

[0077] like Figure 2 and Figure 3 As shown, the gas-water mixer 5 is a tubular structure. The water inlet pipe 52 is located at one end of the tubular structure and is arranged tangentially to the tubular structure. The end of the air inlet pipe 51 is located inside the water inlet pipe 52. To ensure effective mixing, the angle between the air inlet pipe 51 and the water inlet pipe 52 is 90°, and an elbow is provided at the end of the air inlet pipe 51 to align the flow directions of the gas and water. The mixed liquid outlet 53 of the gas-water mixer 5 is located on the opposite side of the water inlet pipe. This effectively prolongs the gas-liquid mixing time, allowing the gas and liquid to mix evenly within the tubular structure before flowing out.

[0078] like Figure 8 and Figure 9 As shown, the oxygen separation device 8 is composed of a mixed liquid inlet 82, an air outlet 81, a water outlet 84, a support leg 83, a swirl baffle 85 and an umbrella cap 86.

[0079] The mixed liquid inlet 82 is arranged tangentially along the side wall of the shell of the oxygen separation device 8 .

[0080] The swirl baffle 85 rotates downward along the inner wall of the device in the oxygen separation device, and is formed by connecting the swirl baffle high end 851 located at the upper part of the oxygen separation device 8 and the swirl baffle low end 852 located at the lower part. Figure 10 shown.

[0081] The umbrella cap 86 is located below the air outlet 81 .

[0082] like Figure 6 and Figure 7 As shown, the mixer 19 is composed of a main mixing pipe 191 and a plurality of branch mixing pipes 192, a nozzle 193, and a mixer inlet 194;

[0083] The angle between the branch pipe 192 and the mixer inlet 194 is less than 90°.

[0084] The branch pipe 192 and the nozzle 193 are connected by threads, flanges or welding.

[0085] like Figure 5 As shown, the sewage adding device 9 is composed of a water inlet 91 , a sewage main pipe 92 and a plurality of sewage branch pipes 93 .

[0086] The sewage branch pipe 93 is provided with water distribution holes 94 at equal intervals, and the diameter of the water distribution holes is 20 to 38 mm.

[0087] The water distribution holes 94 are staggered and opened at an angle of 45 degrees downward to prevent suspended matter in the sewage from flowing into the holes and causing blockage.

[0088] The medium flow velocity in the sewage main pipe 92 is greater than the medium flow velocity in the branch pipe 93 .

[0089] The flow rate of the medium in the sewage branch pipe 93 is greater than the flow rate of the water distribution hole 94.

[0090] The sewage dosing device 9 can also be used for backwashing the air intake.

[0091] A packing layer is provided on the cross section of the reactor. The upper packing layer is a supported catalyst, the lower packing layer is a supporting packing, and the filter plate is located below the supporting layer.

[0092] The carrier of the supported catalyst can be γ-Al2O3, silicon aluminum, titanium oxide, etc., and the active ingredient is nitrate or oxide of transition metal ions that have catalytic effect on ozone, such as Cu, Mn, Co, Ni, Ti, Ce, Fe, etc.

[0093] The supported catalyst has a particle size of 3-7 mm and a bulk density of 0.6-1.1 g / cm 3 , specific surface area ≥ 200m 2 / g, pore volume ≥ 0.3m 3 / g, compressive strength ≥130N / particle, abrasion rate <0.5%, water absorption rate ≥40%, active component content >90%, service life >10 years.

[0094] The lower supporting layer is filled with pebbles, and the particle size of the supporting layer gradually decreases from bottom to top, and the particle size of the catalyst contact part is twice that of the catalyst. The height of the supporting layer is generally 400-600mm.

[0095] Below the supporting layer filler is a filter plate, which can support the catalyst filler and the supporting layer filler and can play a role in uniform water distribution.

[0096] The sewage passes through the sewage inlet 2, and part of it is mixed with ozone in the water-gas mixer 5 through the booster pump 3 and then enters the water-gas separation device 8, and then enters the reactor 11 through the mixer 19; the other part directly enters the reactor 11 through the sewage dosing device 9. The two parts of sewage are oxidized in the reactor 11 and then discharged from the outlet 19.

[0097] Oxygen enters the ozone generator 10 through the air inlet 1. The gas containing high concentration of ozone generated by the ozone generator 10 enters the water-gas mixer 5 through the flow controller 7 and the one-way control valve 6. The ozone is mixed with sewage in the water-gas mixer 5 and then enters the ozone separation device 8. The gas containing low concentration of ozone separated from the ozone separation device 8 enters the gas purification device 12 through the one-way circulation valve 15. The purified gas is mixed with oxygen and then enters the air inlet 1, thereby realizing the recovery and reuse of oxygen.

[0098] Ozone-dissolved wastewater from ozone separation device 8 enters reactor 11, where it mixes with ozone-free wastewater. The mixed wastewater then flows through a fixed packing layer. As it flows through the packing layer, ozone is catalyzed to produce highly oxidizing free radicals. These free radicals oxidize and degrade organic pollutants in the wastewater, ultimately treating the wastewater. The wastewater flows through the packing layer for 10 to 30 minutes.

[0099] The gas in the reactor 11 enters the tail gas destruction device 13 , and is discharged from the exhaust port 18 after being treated by the tail gas destruction device 13 and passing the treatment.

[0100] A flow controller 4 is provided between the booster pump 3 and the water-gas mixer 5 to control the flow of the sewage.

[0101] A flow controller 7 is provided between the ozone generator 10 and the water-gas mixer 5 to control the flow of ozone.

[0102] The ratio of the sewage volume measured by the flow controller 4 to the gas volume measured by the flow controller 7 is 1:1 to 6:1.

[0103] Negative pressure is generated in the gas-water mixer 5, and the gas is sucked in by relying on the negative pressure.

[0104] The wastewater containing ozone enters the ozone separation device 8 tangentially. A baffle or screen is provided in the water-gas separation device 8 , and the internal pressure is controlled at 0.2-0.6 MPa, which can ensure that the oxygen content in the separated gas is greater than 90%.

[0105] The reactor 11 is provided with a sewage dosing device 9 and a mixer 19, which can fully mix the sewage containing ozone with the sewage containing no ozone to ensure the treatment effect.

[0106] The sewage dosing device 9 and the mixer 19 are composed of 316 or 316L pipes with micropores of different specifications, and the micropores are evenly distributed at the oblique lower part of the pipes.

[0107] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A sewage ozone catalytic oxidation process, characterized in that: The steps include: After the sewage and ozone are initially mixed, they enter the tubular structure at high speed and tangentially under the pumping of a high-pressure water pump. The tubular structure is violently turbulent, thereby cutting the large ozone bubbles into fine bubbles, allowing the ozone to fully dissolve in the sewage to obtain a gas-water mixture; The gas-water mixture is transported to the oxygen separation device for oxygen separation, and the wastewater with oxygen removed is transported to the mixer at the bottom of the reactor for liquid distribution; The un-ozoned sewage is pumped directly into the reactor and added above the mixer; When the mixture of sewage and ozone flows through the catalyst layer in the reactor, the sewage is catalytically oxidized and degraded; When the amount of sewage to be treated is large, only part of the sewage is needed to dissolve ozone, and the rest of the sewage goes directly into the reactor; In the reactor, wastewater with ozone dissolved in it is sprayed upward at an angle, and wastewater without ozone is sprayed downward at an angle, and the two are sheared and mixed with each other. The sewage ozone catalytic oxidation process adopts a sewage ozone catalytic oxidation system, which comprises a gas-water mixer, an oxygen separation device and a reactor connected in sequence, wherein: The air-water mixer is a tubular structure, the water inlet pipe is located at one end of the tubular structure, and the side is tangent to the tubular structure, and the end of the air inlet pipe is located inside the water inlet pipe; The water inlet pipe is connected to the sewage source through a high-pressure pump, and the air inlet pipe is connected to the ozone generator; A sewage dosing device and a mixer are provided at the bottom of the reactor, and the sewage dosing device is provided above the mixer and is connected to a sewage source; The mixer is connected to the oxygen separation device; The end of the air inlet pipe is located inside the water inlet pipe, the angle between the air inlet pipe and the water inlet pipe is 85°-95°, and an elbow is provided at the end of the air inlet pipe so that the gas flow direction is the same as the water flow direction; The oxygen separation device is a vertical shell structure, with a baffle or a wire mesh inside, and the internal pressure is controlled at 0.2-0.6MPa; the mixed liquid inlet is tangentially arranged along the side of the vertical shell, and a swirl baffle is arranged inside the shell, and the swirl baffle rotates downward along the inner wall of the device in the oxygen separation device; The sewage dosing device comprises a sewage main pipe and a plurality of sewage branch pipes connected to the sewage main pipe, wherein water distribution holes are provided on the sewage branch pipes, and the water distribution holes are arranged obliquely toward the bottom of the reactor; the water distribution holes are arranged in different oblique directions; The mixing branch pipe of the mixer is arranged upwardly inclined relative to the horizontal direction, and the inclination angle is 5°-30°; The gas outlet of the oxygen separation device is arranged at the top, the water outlet is arranged at the bottom, and a baffle element is arranged below the gas outlet.

2. The wastewater ozone catalytic oxidation process according to claim 1, characterized in that: The deflector element is an umbrella-shaped structure, which completely covers the air outlet, and the tip of the cap faces the air outlet.

3. The wastewater ozone catalytic oxidation process according to claim 1, characterized in that: A second flow controller and a second one-way valve are arranged between the ozone generator and the gas-water mixer, and the second one-way valve is located between the second flow controller and the gas-water mixer.

4. The wastewater ozone catalytic oxidation process according to claim 1, characterized in that: It also includes a gas purification device, which is connected to the oxygen separation device and the ozone generator respectively.

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