A micro-nano bubble ozone catalytic oxidation reaction system

Abstract

The invention relates to a micro-nano bubble ozone catalytic oxidation reaction system, comprising an oxygen cylinder, an ozone generator, a micro-nano bubble generator and a reactor which are connected in sequence, wherein the micro-nano bubble generator inputs ozone micro-nano bubbles into the reactor; the reactor comprises from bottom to top a first water distributor, a second water distributor, a plurality of packing layers, a water outlet and a tail gas outlet, a water inlet pipe is connected to the first water distributor, and the micro-nano bubble generator is connected to the second water distributor; a screen and a third water distributor are sequentially arranged on the top of the packing layer, a plurality of grooves protruding upwards are evenly distributed on the surface of the screen, the third water distributor is arranged above the screen, a water outlet hole corresponds to the position of the groove, and is used for downward aeration while using airflow to flush out catalyst fillers blocked in the grooves, so that the catalyst fillers are in a flowing state, thereby promoting contact between sewage and the catalyst fillers.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and in particular relates to a micro-nano bubble ozone catalytic oxidation reaction system. Background Art

[0002] Advanced oxidation method is one of the most effective methods for treating industrial wastewater. Among them, ozone advanced oxidation technology has received widespread attention in the field of wastewater treatment due to its advantages such as strong oxidizing ability, no chemical sludge production, no secondary pollution, and small footprint. Ozone catalytic oxidation technology is more efficient than single ozone oxidation and shows excellent organic matter degradation ability.

[0003] However, ozone catalytic oxidation is a chemical reaction controlled by chemical mass transfer. The apparent reaction rate depends on the mass transfer rate of ozone from the gas phase to the liquid phase. The low gas-liquid mass transfer rate of traditional aeration methods has become the main factor limiting the improvement of the apparent reaction rate of ozone oxidation. Summary of the invention

[0004] In view of the above problems, the present invention provides a micro-nano bubble ozone catalytic oxidation reaction system, which uses micro-nano bubbles to provide ozone to the reactor, thereby improving the mass transfer rate of ozone from the gas phase to the liquid phase and increasing the ozone oxidation reaction rate.

[0005] The micro-nano bubble ozone catalytic oxidation reaction system comprises an oxygen cylinder, an ozone generator, a micro-nano bubble generator and a reactor which are connected in sequence, and the micro-nano bubble generator inputs ozone micro-nano bubbles into the reactor;

[0006] The reactor comprises, from bottom to top, a first water distributor, a second water distributor, a plurality of packing layers, a water outlet and a tail gas outlet, a water inlet pipe is connected to the first water distributor, and a micro-nano bubble generator is connected to the second water distributor;

[0007] A screen and a third water distributor are sequentially arranged on the top of the packing layer. A plurality of upwardly protruding grooves are evenly distributed on the surface of the screen. The third water distributor is arranged above the screen. The water outlets correspond to the positions of the grooves. The third water distributor is used for downward aeration and at the same time utilizes the airflow to flush open the catalyst packing blocked in the groove, so that the catalyst packing is in a flowing state, thereby promoting the contact between the sewage and the catalyst packing.

[0008] The present invention provides ozone to the reactor in the form of micro-nano bubbles, which refer to tiny bubbles with a diameter between tens of micrometers and hundreds of nanometers, and have the characteristics of large specific surface area, large internal pressure, etc., which are conducive to gas-liquid mass transfer. The micro-nano bubbles have a slow rising rate and a long residence time in sewage, which can increase the contact time with pollutants and help improve the utilization rate of ozone. The surface of the micro-nano bubbles carries a negative charge, which greatly increases the electrostatic adsorption of the gas-liquid surface. The -OH free radicals and -O free radicals generated by the micro-nano bubbles when they burst have a high redox potential, which is conducive to the efficient degradation of organic pollutants.

[0009] Traditional catalyst packing is loaded between the upper and lower screens in the form of regular packing. The packing cannot be moved. When the sewage flows through the packing layer, it contacts the catalyst packing and degrades the pollutants in the sewage through chemical reactions. In this way, the packing is fixed and squeezed against each other, and the catalyst surface cannot be fully contacted with the sewage. The fixed packing is also prone to cause dead zones or channel flow in the water flow, and it is easy to accumulate dirt, all of which lead to insufficient utilization of the active catalytic sites of the catalyst packing.

[0010] The present invention designs the packing layer to be flowable within the packing layer area, so that the surface of the catalyst packing can all contact the sewage, and the flowing packing can also prevent dirt from accumulating and shielding the active catalytic sites, thereby improving the utilization rate of the catalyst. Since the sewage flows from bottom to top in the reactor, in order to shape the flow environment in the packing layer, the present invention creatively arranges a third water distributor capable of downward aeration on the screen of the packing layer to provide a downward driving force for the packing. Moreover, in conjunction with aeration, a number of upwardly protruding grooves are evenly arranged on the screen. When aeration pushes the packing at the groove downward, the packing at the horizontal screen around the groove will automatically gather in the groove, and the packing in the groove will be pushed downward again during the next aeration, and so on, forming a number of circulations centered on the groove, the packing at the groove moves downward, and the packing around the groove first moves upward, and then moves into the groove, and so on, in a cycle. The third water distributor can be aerated intermittently or continuously.

[0011] Optionally, compressed oxygen is stored in the oxygen cylinder, the opening of the oxygen cylinder is connected to the inlet of the ozone generator through a pipeline, the outlet of the ozone generator is connected to the air inlet of the micro-nano bubble generator, and the air outlet of the micro-nano bubble generator is connected to the second water distributor.

[0012] Optionally, the inlet of the first water distributor is a reflux inlet and a water inlet, and the top of the reactor is provided with a water outlet and a reflux outlet, and the reflux outlet is connected to the micro-nano bubble generator and the reflux inlet through a first reflux pipe and a second reflux pipe, respectively, for inputting part of the reflux water of the reactor into the micro-nano bubble generator and returning to the first water distributor;

[0013] The first reflux pipe is provided with a pressurized water pump for pressurizing the reflux water and then inputting it into the micro-nano bubble generator.

[0014] Optionally, observation holes and sampling holes are provided on the side wall of the reactor above or below each packing layer to facilitate real-time observation of the situation inside the reactor and sampling and testing of the sewage treatment situation.

[0015] Optionally, an overflow weir is provided at the water outlet so that the sewage after the ozone catalytic oxidation treatment overflows and is discharged from the water outlet.

[0016] Optionally, the tail gas outlet is connected to a tail gas treatment device through an air path, and the remaining ozone and other waste gases in the tail gas are treated before being discharged into the atmosphere.

[0017] Optionally, the thickness of the plurality of packing layers decreases from bottom to top, and a support net is provided at the bottom of each packing layer for supporting the catalyst packing.

[0018] Optionally, the shape of the vertical cross section of the groove is selected from a triangle, a trapezoid, a square, and a semicircle.

[0019] Optionally, the inlet of the third water distributor is connected to the outlet of the micro-nano bubble generator, and the filler layer is aerated by using ozone micro-nano bubbles.

[0020] Optionally, the shape of the filler is large at both ends and small in the middle, and the two ends to the middle of the filler are smooth inclined surfaces, that is, the outer diameter of the filler gradually decreases from the two ends to the middle;

[0021] The interior of the filler has a cylindrical through hole, so that the interior of the filler is hollow. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a micro-nano bubble ozone catalytic oxidation reaction system;

[0023] Figure 2 It is a structural schematic diagram of the screen and the third water distributor;

[0024] Figure 3 Schematic diagram of the filler structure.

[0025] In the accompanying drawings, 1-oxygen cylinder, 2-ozone generator, 3-micro-nano bubble generator, 4-reactor, 5-first water distributor, 6-second water distributor, 7-packing layer, 8-water outlet, 9-exhaust outlet, 10-screen, 11-third water distributor, 12-groove, 13-water outlet, 14-reflux inlet, 15-water inlet, 16-reflux outlet, 17-first reflux pipe, 18-second reflux pipe, 19-pressurized water pump, 20-observation hole, 21-sampling hole, 22-overflow weir, 23-packing, 24-through hole, 25-inclined surface. DETAILED DESCRIPTION

[0026] This embodiment provides a micro-nano bubble ozone catalytic oxidation reaction system, such as Figure 1-Figure 3 As shown, it includes an oxygen cylinder 1, an ozone generator 2, a micro-nano bubble generator 3 and a reactor 4 which are connected in sequence, and the micro-nano bubble generator 3 inputs ozone micro-nano bubbles into the reactor 4;

[0027] The reactor 4 includes, from bottom to top, a first water distributor 5, a second water distributor 6, several layers of filler layers 7, a water outlet 8 and a tail gas outlet 9, the water inlet pipe is connected to the first water distributor 5, and the micro-nano bubble generator 3 is connected to the second water distributor 6;

[0028] A screen 10 and a third water distributor 11 are provided on the top of the packing layer 7 in sequence. A plurality of upwardly protruding grooves 12 are evenly distributed on the surface of the screen 10. The third water distributor 11 is provided above the screen 10. The water outlet holes 13 correspond to the positions of the grooves 12 and are used for downward aeration while utilizing airflow to flush open the catalyst packing blocked in the grooves 12, so that the catalyst packing is in a flowing state, thereby promoting the contact between the sewage and the catalyst packing.

[0029] Optionally, compressed oxygen is stored in the oxygen cylinder 1, the opening of the oxygen cylinder 1 is connected to the inlet of the ozone generator 2 through a pipeline, the outlet of the ozone generator 2 is connected to the air inlet of the micro-nano bubble generator 3, and the air outlet of the micro-nano bubble generator 3 is connected to the second water distributor 6. In the present invention, oxygen is input into the ozone generator 2 to prepare ozone, and the prepared ozone is input into the micro-nano bubble generator 3 to generate ozone micro-nano bubbles, which are then input into the reactor 4.

[0030] Optionally, the inlet of the first water distributor 5 is a reflux inlet 14 and a water inlet 15, and the top of the reactor 4 is provided with a water outlet 8 and a reflux outlet 16, and the reflux outlet 16 is connected to the micro-nano bubble generator 3 and the reflux inlet 14 through a first reflux pipe 17 and a second reflux pipe 18, respectively, for inputting part of the reflux water of the reactor 4 into the micro-nano bubble generator 3 and returning to the first water distributor 5;

[0031] The first reflux pipe 17 is provided with a pressurized water pump 19 for pressurizing the reflux water and then inputting it into the micro-nano bubble generator 3 .

[0032] In the present invention, the pressurized reflux water is fully mixed with ozone to generate micro-nano bubbles, which are then input into the reactor 4 at normal pressure, i.e., ozone micro-nano bubbles are provided to the reactor 4 by means of pressurized dissolved gas-decompressed release. Due to the sudden drop in pressure, a large amount of micro-nano ozone bubbles are released.

[0033] Optionally, the first water distributor 5 and the second water distributor 6 are both jet water distributors.

[0034] Optionally, an observation hole 20 and a sampling hole 21 are provided on the side wall of the reactor 4 above or below each packing layer 7, so as to facilitate real-time observation of the situation in the reactor 4 and sampling and testing of the sewage treatment situation.

[0035] Optionally, an overflow weir 22 is provided at the water outlet 8 so that the sewage after the ozone catalytic oxidation treatment overflows and is discharged from the water outlet 8 .

[0036] Optionally, the tail gas port 9 is connected to a tail gas treatment device through a gas path, and the remaining ozone and other waste gases in the tail gas are treated before being discharged into the atmosphere.

[0037] Optionally, the thickness of the several packing layers 7 decreases from bottom to top, so as to save the longitudinal space of the reactor 4 while ensuring the sewage treatment effect; a support net is provided at the bottom of each packing layer 7 to support the catalyst packing. The mesh size of the screen 10 is smaller than the size of the packing to prevent the packing from being lost.

[0038] Optionally, the shape of the vertical cross section of the groove 12 is selected from a triangle, a trapezoid, a square, a semicircle, preferably a triangle or a trapezoid, so that the filler can enter the groove 12 along the inclined side of the groove 12 with less impact on the groove 12.

[0039] Optionally, the inlet of the third water distributor 11 is connected to the outlet of the micro-nano bubble generator 3, and the packing layer 7 is impacted by ozone micro-nano bubbles and sewage. The present invention inputs ozone micro-nano bubbles into the reactor 4 through the second water distributor 6, and the bubbles pass through each packing layer 7 upward. At the same time, the third water distributor 11 of each packing layer 7 inputs ozone micro-nano bubbles into the corresponding packing layer 7, and while impacting the packing at the groove 12, it can also form a downward airflow and water flow in the packing layer 7, which interacts with the upward airflow, increases the disturbance of the sewage in the packing layer 7, promotes the movement of the packing, promotes the contact between the sewage and the catalyst packing, and improves the treatment efficiency. The water and air intake of the third water distributor 11 is less than that of the second water distributor.

[0040] Optionally, the shape of the filler 23 is large at both ends and small in the middle, and the filler 23 is a smooth inclined surface from both ends to the middle, that is, the outer diameter of the filler gradually decreases from both ends to the middle;

[0041] The filler 23 has a cylindrical through hole 24 inside so that the inside of the filler is hollow.

[0042] Further optionally, the through hole 24 is provided with inclined surfaces 25 at both ends of the filler, and the diameter of the ring surrounded by the inclined surfaces 25 near the middle of the filler is smaller than the diameter near the end of the filler, so that the through hole 24 has an outwardly expanding inclined surface similar to a bell mouth.

[0043] The present invention also makes a special design for the structure of the filler, with large ends, a small middle and a smooth inclined surface, so that the filler 23 can rotate continuously under the action of water flow and air flow, promoting all-round contact between sewage and the filler 23. During the rotation process, the through hole 24 inside it changes its orientation continuously, and water and air can flow through it at the same time, and bubbles are formed at the edge of the through hole 24 and then discharged from the through hole, achieving the effect of regenerating bubbles. The inclined surface 25 at the edge of the through hole is conducive to the formation of bubbles.

[0044] The catalyst component of the catalyst filler can be a common ozone catalytic oxidation catalyst, for example, including a variety of metals and metal oxides. Those skilled in the art can adjust the components and dosage according to actual sewage needs, and shape it in a small amount of solvent or liquid environment during preparation, and calcine it at an appropriate temperature.

Claims

1. A micro-nano bubble ozone catalytic oxidation reaction system, characterized in that: The micro-nano bubble ozone catalytic oxidation reaction system comprises an oxygen cylinder, an ozone generator, a micro-nano bubble generator and a reactor which are connected in sequence, and the micro-nano bubble generator inputs ozone micro-nano bubbles into the reactor; The reactor comprises, from bottom to top, a first water distributor, a second water distributor, a plurality of packing layers, a water outlet and a tail gas outlet, a water inlet pipe is connected to the first water distributor, and a micro-nano bubble generator is connected to the second water distributor; A screen and a third water distributor are sequentially arranged on the top of the packing layer, a plurality of upwardly protruding grooves are evenly distributed on the surface of the screen, and the third water distributor is arranged above the screen, and the water outlet corresponds to the position of the groove, and is used for downward aeration, while using the airflow to flush the catalyst packing blocked in the groove, so that the catalyst packing is in a flowing state, and the contact between the sewage and the catalyst packing is promoted; The shape of the filler is large at both ends and small in the middle, the two ends to the middle of the filler are smooth inclined curved surfaces, and the outer diameter of the filler gradually decreases from the two ends to the middle; The filler has a cylindrical through hole inside, so that the inside of the filler is hollow; Compressed oxygen is stored in the oxygen cylinder, the opening of the oxygen cylinder is connected to the inlet of the ozone generator through a pipeline, the outlet of the ozone generator is connected to the air inlet of the micro-nano bubble generator, and the air outlet of the micro-nano bubble generator is connected to the second water distributor; The inlet of the first water distributor is a reflux inlet and a water inlet, and the top of the reactor is provided with a water outlet and a reflux outlet, and the reflux outlet is connected to the micro-nano bubble generator and the reflux inlet through the first reflux pipe and the second reflux pipe respectively, so as to input part of the reflux water of the reactor into the micro-nano bubble generator and return to the first water distributor; The first reflux pipe is provided with a pressurized water pump for pressurizing the reflux water and then inputting it into the micro-nano bubble generator.

2. The micro-nano bubble ozone catalytic oxidation reaction system according to claim 1 is characterized in that: The thickness of the several packing layers decreases from bottom to top, and a support net is provided at the bottom of each packing layer for supporting the catalyst packing.

3. The micro-nano bubble ozone catalytic oxidation reaction system according to claim 1 is characterized in that: The shape of the vertical cross section of the groove is selected from a triangle, a trapezoid, a square, and a semicircle.

4. The micro-nano bubble ozone catalytic oxidation reaction system according to claim 1, characterized in that: The inlet of the third water distributor is connected to the outlet of the micro-nano bubble generator, and the filler layer is aerated by using ozone micro-nano bubbles.

5. The micro-nano bubble ozone catalytic oxidation reaction system according to claim 1, characterized in that: Observation holes and sampling holes are provided on the side wall of the reactor above or below each packing layer, which are convenient for real-time observation of the situation inside the reactor and sampling and testing of the sewage treatment situation.

6. The micro-nano bubble ozone catalytic oxidation reaction system according to claim 1, characterized in that: An overflow weir is arranged at the water outlet so that the sewage after the ozone catalytic oxidation treatment overflows and is discharged from the water outlet.

7. The micro-nano bubble ozone catalytic oxidation reaction system according to claim 1, characterized in that: The tail gas outlet is connected to the tail gas treatment device through an air path, and the remaining ozone and other waste gases in the tail gas are treated before being discharged into the atmosphere.

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