WO2024146261A1

WO2024146261A1 - Ozone flotation treatment process for combined sewage overflow

Info

Publication number: WO2024146261A1
Application number: PCT/CN2023/130731
Authority: WO
Inventors: 汤丁丁; 周艳; 夏云峰; 毛旭辉; 汪小东; 刘军; 赵皇; 姜永祯; 邓德宇; 秦长金; 屈天晓; 李进; 宁梓琦; 郑碧娟; 王媛
Original assignee: 中建三局绿色产业投资有限公司
Priority date: 2023-02-07
Filing date: 2023-11-09
Publication date: 2024-07-11

Abstract

An ozone flotation treatment process for combined sewage overflow. Sewage sequentially flows through a reaction zone (21), a contact zone (22), a separation zone (23) and a catalysis zone (24) of a main reaction container (2), and in the main reaction container (2), an ozone floatation treatment is performed on the sewage; and an agent adding unit (1) and an ozone generation unit (3) are connected to the main reaction container (2), wherein the agent adding unit (1) is used for adding an agent to sewage under treatment for coagulation, and the ozone generation unit (3) is used for adding ozone into the main reaction container (2) to improve the ozone mass transfer efficiency; and a rapid and efficient treatment of combined sewage overflow is achieved by means of coagulation, dissolved air flotation and catalytic ozonation, such that the concentration of suspended solids, total phosphorus and COD in a water body can be effectively reduced, and the effective removal of typical pollutants in the sewage overflow is ensured.

Description

Ozone flotation treatment process for combined sewer overflow sewage

Technical Field

The invention relates to the technical field of sewage treatment, and in particular to an ozone flotation treatment process for combined sewer overflow sewage.

Background technique

In recent years, urban rainstorm pollution incidents have occurred frequently, resulting in large combined sewer overflow sewage flows and a wide range of impacts. This is one of the main causes of urban odorous black water bodies, surface water pollution, and water environment deterioration. Therefore, combined sewer overflow pollution control has become an important issue that cannot be avoided and needs to be solved urgently.

Ozone flotation is a powerful technical means to degrade typical pollutants in CSOs, and can adapt to the complex and variable water quality and volume of combined sewer overflow pollution. Existing ozone flotation devices have disadvantages such as low treatment efficiency and unstable treatment effect. If coagulation and ozone flotation can be used to effectively degrade water pollutants and achieve rapid, efficient and large-volume emergency treatment of sewage, it will be of great significance for the control of combined sewer overflow sewage.

Summary of the invention

The main purpose of the present invention is to provide an ozone flotation treatment process for combined sewer overflow sewage.

To achieve the above object, the present invention provides an ozone flotation treatment process for combined sewer overflow sewage, comprising the following treatment steps:

(1) The sewage is introduced into a reaction zone, at least one first titanium aeration disk is provided at the bottom of the reaction zone, ozone is introduced into the reaction zone through the first titanium aeration disk, a coagulant PAC and a coagulant aid PAM are added into the reaction zone, and coagulation and ozone synergistic treatment is performed;

(2) passing the sewage treated in step (1) into a contact zone, wherein a dissolved air releaser is provided at the bottom of the contact zone, and ozone is passed into the contact zone through the dissolved air releaser, and floc particles formed after coagulation float up to form scum;

(3) passing the sewage treated in step (2) into a separation zone to remove scum and sludge in the sewage;

(4) The wastewater treated in step (3) is passed into a catalytic zone, wherein the catalytic zone is provided with ozone catalytic filler, and the wastewater is subjected to catalytic oxidation treatment.

Furthermore, a water inlet unit is provided, the water inlet unit comprising a water inlet pipe connected to the reaction zone and a lift pump and an electromagnetic flowmeter installed on the water inlet pipe, the water inflow of the sewage is 2-15 m ³ /h, which is adjusted by the electromagnetic flowmeter.

Furthermore, the porosity of the ozone catalytic filler in the catalytic zone is 25% to 45%.

Furthermore, a reagent dosing unit is provided, which comprises a coagulant solution barrel and a coagulant aid solution barrel, wherein the coagulant solution barrel and the coagulant aid solution barrel are respectively connected to the reaction zone through dosing pipes, and a diaphragm metering pump is installed on the dosing pipes.

Furthermore, a main reaction container is provided, in which a first stainless steel baffle, a baffle plate and a second stainless steel baffle plate are fixed in sequence from left to right, and the first stainless steel baffle plate, the baffle plate and the second stainless steel baffle plate separate the main reaction container into a reaction zone, a contact zone, a separation zone and a catalytic zone.

Furthermore, an ozone generating unit is provided, which includes an ozone generator. The ozone concentration generated by the ozone generator is 90-135 mg/L. The ozone is divided into two paths and respectively introduced into the first titanium aeration disk and the dissolved air releaser. The flow ratio of the two parts of ozone gas is 1:1 to 1:2.

Furthermore, a residual ozone treatment unit is provided, which includes a rotary fan and at least one second titanium aeration plate arranged at the bottom of the catalytic zone, the air inlet of the rotary fan is connected to the separation zone, and the air outlet of the rotary fan is connected to the second titanium aeration plate.

Furthermore, a chain scraper is provided at the top of the separation zone, and a mud discharge pipe with inclined plates on both sides is provided at the bottom of the separation zone. A slag discharge plate is also provided in the separation zone, and the slag discharge plate is located at the lower right side of the chain scraper. The slag discharge plate includes an L-shaped plate and an inclined plate connected to the top of the vertical edge of the L-shaped plate. The horizontal edge of the L-shaped plate is connected to the second stainless steel baffle plate, and the L-shaped plate and the second stainless steel baffle plate form a slag discharge trough.

Furthermore, a gas-liquid mixing pump and an air dissolving tank are provided, the gas inlet of the gas-liquid mixing pump is connected to the ozone generator, the liquid inlet of the gas-liquid mixing pump is connected to the catalytic zone, the outlet of the gas-liquid mixing pump is connected to the inlet of the air dissolving tank, and the outlet of the air dissolving tank is connected to the dissolved air releaser.

Furthermore, the gas-liquid ratio in the gas-liquid mixing pump is 1:9 to 1:10.

Furthermore, it also includes a tail gas destroyer, which is connected to the catalytic zone through a tail gas collection pipe.

The beneficial effects of the present invention are embodied in:

The present invention breaks through the limitation of dissolved air volume on traditional devices, greatly improves the ozone mass transfer efficiency, and simultaneously enhances the ozone microbubble oxidation and coagulation flotation effects; utilizes the active oxygen free radicals generated by catalytic oxidation to non-selectively oxidize difficult-to-degrade organic matter, enhances the removal effect of organic matter, greatly improves the treatment efficiency of the device, and improves the utilization rate of ozone at the same time; the skid-mounted device can realize the rapid and efficient treatment of combined sewer overflow sewage, has the advantages of good treatment effect, resistance to shock load, no permanent land occupation, easy mobile scheduling, flexible operation mode, convenient operation and management, excellent applicability, etc., can be industrialized, and has good engineering application prospects.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an overall device according to an embodiment of the present invention.

Explanation of reference numerals: 1. reagent dosing unit; 2. main reaction vessel; 3. ozone generating unit; 4. water inlet unit; 5. residual ozone treatment unit; 21. reaction zone; 22. contact zone; 23. separation zone; 24. catalytic zone; 26. mixer; 27. slag discharge plate; 234. inclined plate; 235. L-shaped plate; 211. first titanium aeration plate; 221. dissolved air releaser; 11. coagulant dissolving barrel; 12. coagulant aid dissolving barrel; 13. diaphragm meter; 14. dosing pipe; 31. Ozone generator; 7. First stainless steel baffle; 8. Baffle; 71. Second stainless steel baffle; 231. Chain scraper; 233. Slag chute; 232. Mud discharge pipe; 242. Ozone catalytic filler; 16. Rotary fan; 32. Dissolved gas tank; 33. Gas-liquid mixing pump; 41. Water inlet pipe; 42. Lifting pump; 43. Electromagnetic flowmeter; 19. Tail gas destroyer; 18. Tail gas collection pipe; 241. Second titanium aeration plate; 15. First stainless steel cover plate; 17. Second stainless steel cover plate.

Specific implementation plan

The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention. Rather than all embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

It should be noted that if the embodiments of the present invention involve directional indications such as up, down, left, right, front, back, etc., then the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture as shown in the accompanying drawings. If the specific posture changes, the directional indication will also change accordingly.

In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and/or" appearing in the full text includes three parallel schemes. Taking "A and/or B" as an example, it includes scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, "multiple" refers to more than two. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

See Figure 1.

The present invention discloses an ozone flotation treatment process for combined sewer overflow sewage, comprising the following treatment steps:

(1) The sewage is introduced into the reaction zone 21, at least one first titanium aeration plate 211 is provided at the bottom of the reaction zone 21, ozone is introduced into the reaction zone 21 through the first titanium aeration plate 211, and a coagulant PAC and a coagulant aid PAM are added into the reaction zone 21 to perform a coagulation and ozone coordinated treatment;

(2) The wastewater treated in step (1) is introduced into a contact zone 22, wherein a dissolved air releaser 221 is provided at the bottom of the contact zone 22, and ozone is introduced into the contact zone 22 through the dissolved air releaser 221, and floc particles formed after coagulation float to form scum;

(3) passing the sewage treated in step (2) into the separation zone 23 to remove scum and sludge in the sewage;

(4) The wastewater treated in step (3) is passed into a catalytic zone 24, wherein the catalytic zone 24 is provided with an ozone catalytic filler 242, to perform catalytic oxidation treatment on the wastewater.

The coagulant is polyaluminium chloride PAC, and the coagulant aid is polyacrylamide PAM. In the reaction zone 21, the sewage is fully mixed with the coagulant PAC and the coagulant aid PAM to form floc particles. At the same time, the sewage reacts with ozone, and the synergistic effect of coagulation and ozone is used to efficiently remove typical pollutants in the combined sewer overflow: typical pollution indicators such as chemical oxygen demand (COD), suspended solids (SS), and total phosphorus (TP); after the sewage is discharged from the bottom of the reaction zone 21, it enters the contact zone 22. Under the action of ozone microbubbles, the floc particles float to form scum, and the water flows into the separation zone 22 to remove the scum on the surface of the sewage and extract the sludge that sinks to the bottom; the effluent after solid-liquid separation enters the catalytic zone 24, and under the action of ozone catalytic filler, it further catalytically oxidizes and removes the remaining organic matter, and reduces COD again. A part of the effluent after the reaction flows back to the front contact zone 22 for secondary removal of pollutants, and the rest is directly discharged.

The design of the present invention breaks through the limitation of dissolved air volume in the traditional device by adding a titanium aeration plate (the diameter of the titanium aeration plate is 100 mm) at the front end of the traditional horizontal flow flotation device. The sewage fully reacts with the ozone released by the first titanium aeration plate 211 at the bottom of the reaction zone 21, and the synergistic effect of coagulation and ozone flotation is utilized to realize the efficient removal of typical pollutants COD, SS and TP in the combined sewer overflow.

In one embodiment, a water inlet unit 4 is provided, and the water inlet unit 4 comprises a water inlet pipe 41 connected to the reaction zone 21, and a lift pump 42 and an electromagnetic flowmeter 43 installed on the water inlet pipe 41. The water inlet rate of the sewage is 2-15 m ³ /h, which is adjusted by the electromagnetic flowmeter 43. This design effectively controls the water inlet rate of the sewage entering the main reaction container.

In one embodiment, the porosity of the ozone catalytic filler 242 of the catalytic zone 24 is 25% to 45%. In this design, the active oxygen free radicals generated by catalytic oxidation are used to non-selectively oxidize and degrade organic matter, thereby enhancing the removal effect of organic matter, greatly improving the treatment efficiency of the device, and also improving the utilization rate of ozone. The catalytic filler can be an ozone catalyst, and there is no limitation on the specific composition, such as an alumina-based ozone catalyst.

In one embodiment, a reagent dosing unit 1 is provided, wherein the reagent dosing unit 1 comprises a coagulant solution barrel 11 and a coagulant aid solution barrel 12. They are connected to the reaction zone 21 through the dosing pipe 14, and a diaphragm metering pump 13 is installed on the dosing pipe 14. In this design, the coagulant (polyaluminium chloride PAC) and the coagulant aid (polyacrylamide PAM) are put into the reaction zone to react with the sewage to achieve coagulation, and the diaphragm metering pump 13 effectively controls the rate at which the reagents enter the reaction zone.

In one embodiment, a main reaction container 2 is provided, in which a first stainless steel baffle plate 7, a baffle plate 8 and a second stainless steel baffle plate 71 are fixed in sequence from left to right, and the first stainless steel baffle plate 7, the baffle plate 8 and the second stainless steel baffle plate 71 divide the main reaction container 2 into a reaction zone 21, a contact zone 22, a separation zone 23 and a catalytic zone 24. The upper end of the first stainless steel baffle plate 7 is fixed to the top of the main reaction container 2, and the reaction zone 21 and the contact zone 22 are connected through the gap between the lower end of the first stainless steel baffle plate 7 and the bottom of the main reaction container 2; the lower end of the baffle plate 8 is fixed to the bottom of the main reaction container 2, and the contact zone 22 and the separation zone 23 are connected through the gap between the upper end of the baffle plate 8 and the top of the main reaction container 2, and the baffle plate 8 is arranged to tilt to the right, with an inclination angle of 40° to 55°; the upper end of the second stainless steel baffle plate is fixed to the top of the main reaction container 2, and the separation zone 23 and the catalytic zone 24 are connected through the gap between the lower end of the second stainless steel baffle plate 71 and the bottom of the main reaction container 2. With this design, the main reaction vessel 2 is divided into four areas by an anti-oxidation stainless steel baffle, which effectively controls the flow direction of the sewage in the main reaction vessel 8. After the water is discharged from the bottom of the reaction zone 21, it enters the contact zone 22, and the floc particles float up to form scum under the action of ozone microbubbles released by the dissolved air releaser 221. The water flows along the baffle 8 into the separation zone 23, and then the effluent after solid-liquid separation enters the catalytic zone 24, wherein the floc particles in the contact zone 22 float up along the baffle 8 under the action of ozone microbubbles released by the dissolved air releaser 221 and are guided to the separation zone 23.

In one embodiment, an ozone generating unit 3 is provided, and the ozone generating unit 3 includes an ozone generator 31. The ozone concentration generated by the ozone generator 31 is 90-135 mg/L. The ozone is divided into two paths and respectively introduced into the first titanium aeration disk 211 and the dissolved air releaser 221. The flow ratio of the two parts of ozone gas is 1:1 to 1:2. In this design, the ozone is divided into two paths and respectively introduced into the first titanium aeration disk 211 and the dissolved air releaser 221. The flow ratio of the two parts of ozone gas is adjusted to 1:1 to 1:2 by a gas flow meter. The first titanium aeration disk 211 continuously aerates the sewage in the reaction zone 21 to uniform the water quality; the dissolved air releaser 221 releases the ozone gas. Under the action of ozone microbubbles, the floc particles float up to form scum, which enhances the ozone mass transfer efficiency and reduces energy loss.

In one embodiment, a residual ozone treatment unit 5 is provided, and the residual ozone treatment unit 5 includes a rotary fan 16 and at least one second titanium aeration disk 241 provided at the bottom of the catalytic zone 24, the air inlet of the rotary fan 16 is connected to the separation zone 23, and the air outlet of the rotary fan 16 is connected to the second titanium aeration disk 241. A first stainless steel cover plate 7 is provided on the top of the reaction zone 21, the contact zone 22 and the separation zone 23, and a second stainless steel cover plate 71 is provided on the top of the catalytic zone. The stainless steel cover plate seals the top of the main reaction container 2 to form a relatively closed area of the main reaction container. The rotary fan 16 collects the residual ozone on the top cover and then passes it into the second titanium aeration disk 241 at the bottom of the catalytic zone 24. The wind pressure of the rotary fan 16 is 0.3-0.5 kfg/m ^3. With this design, the ozone escaped in the main reaction container 2 is reused for a second time, and direct destruction is prevented to cause waste of resources, thereby improving the utilization rate of ozone.

In one embodiment, a chain scraper 231 is provided at the top of the separation zone 23, and a mud discharge pipe 232 with inclined plates on both sides is provided at the bottom of the separation zone 23. A slag discharge plate 27 is also provided in the separation zone 24, and the slag discharge plate 27 is located at the lower right side of the chain scraper 231. The slag discharge plate 27 includes an L-shaped plate 235 and an inclined plate 234 connected to the top of the vertical edge of the L-shaped plate 235. The horizontal edge of the L-shaped plate 235 is connected to the second stainless steel baffle 71, and the L-shaped plate 235 and the second stainless steel baffle 71 form a slag discharge trough 233. With this design, when the device is running, the water flow entering the separation zone 23 is separated and scraped to the slag discharge tank 233 by the chain scraper 231. The chain scraper 231 operates intermittently. When the scraper of the chain scraper 231 moves to the upper end of the inclined plate, the bottom of the scraper contacts the inclined surface, and the slag of the sewage is cleaned more completely, and SS, TP and insoluble COD in the water are effectively removed; the inclined plates on both sides of the mud discharge pipe 232 effectively collect the sludge and drain the sludge into the mud discharge pipe 232. The mud discharge pipe 232 is connected to a mud storage tank for collecting sludge. After reaction and separation, the suspended matter in the sewage is greatly reduced, thereby avoiding affecting the activity of the filler in the rear catalytic zone and blocking the catalyst pores.

In one embodiment, a gas-liquid mixing pump 33 and a gas dissolving tank 32 are provided, wherein the gas inlet of the gas-liquid mixing pump 33 is connected to the ozone generator 31, the liquid inlet of the gas-liquid mixing pump 33 is connected to the catalytic zone 24, the outlet of the gas-liquid mixing pump 33 is connected to the inlet of the gas dissolving tank 32, and the gas dissolving tank The outlet of 32 is connected to the dissolved air releaser 221. With this design, part of the ozone generated by the ozone generator 31 directly provides ozone to the first titanium aeration plate 211 to achieve the synchronous reaction of ozone coagulation, and the other part of the ozone is pressurized and dissolved in the return water under the action of the gas-liquid mixing pump; the dissolved air water is then decompressed and released to the bottom of the contact area 22 by the dissolved air releaser 221 for secondary treatment, and the released microbubbles are fully in contact with the raw water after coagulation, the dissolved air pressure is 0.3-0.4MPa, and the diameter of the released microbubbles is 20-30μm.

In one embodiment, the gas-liquid ratio in the gas-liquid mixing pump 33 is 1:9-1:10.

In one embodiment, a tail gas destroyer 19 is provided, and the tail gas destroyer 19 is connected to the catalytic zone 24 through a tail gas collecting pipe 18. In this design, the residual ozone after the reaction in the catalytic zone 24 is processed by the tail gas destroyer 19 and then discharged into the atmosphere, avoiding air pollution.

In one embodiment, it also includes an intelligent control and early warning component, which includes an electronic control system and an ozone sensor. The ozone sensor is arranged above the stainless steel cover plate group and has a folding rod. When the device is shut down, the ozone sensor is laid flat on the stainless steel cover plate. When the device is working, the ozone sensor is turned on and stands upright 2m from the top to monitor the ambient ozone concentration. When the ambient ozone concentration is higher than the threshold of 0.1mg/ _m3 , the electronic control system automatically alarms. With this design, an ozone monitoring and early warning module is arranged on the top of the device, which can be applied to emergency pollution treatment of non-industrial components to ensure the safety of the operating environment and personnel. When the device is shut down, the ozone sensor is laid flat on the top cover to facilitate the movement and scheduling of the device in emergency application scenarios.

The above content is a specific implementation scheme of the present invention and is not limited to the above-mentioned implementation details. Ordinary technicians in this field should understand that they can still modify the above-mentioned implementation scheme, or make equivalent replacements for some of the technical features therein, but any modifications, improvements, etc. made should be included in the protection scope of the present invention.

Claims

An ozone flotation treatment process for combined sewer overflow sewage, characterized in that it comprises the following treatment steps:

(1) passing sewage into a reaction zone (21), wherein at least one first titanium aeration plate (211) is provided at the bottom of the reaction zone (21), passing ozone into the reaction zone (21) through the first titanium aeration plate (211), adding a coagulant PAC and a coagulant aid PAM into the reaction zone (21), and performing a coagulant and ozone synergistic treatment;

(2) passing the sewage treated in step (1) into a contact zone (22), wherein a dissolved air releaser (221) is provided at the bottom of the contact zone (22), and ozone is passed into the contact zone (22) through the dissolved air releaser (221), and floc particles formed after coagulation float to form scum;

(3) passing the sewage treated in step (2) into a separation zone (23) to remove scum and sludge in the sewage;

(4) The sewage treated in step (3) is passed into a catalytic zone (24), wherein the catalytic zone (24) is provided with an ozone catalytic filler (242), and the sewage is subjected to catalytic oxidation treatment.
An ozone flotation process for combined sewer overflow sewage as described in claim 1, characterized in that: a water inlet unit (4) is provided, the water inlet unit (4) comprises a water inlet pipe (41) connected to the reaction zone (21) and a lift pump (42) and an electromagnetic flowmeter (43) installed on the water inlet pipe (41), and the water inlet rate of the sewage is 2 to 15 m/h, which is adjusted by the electromagnetic flowmeter (43).
The ozone flotation treatment process for combined sewer overflow sewage according to claim 1, characterized in that the porosity of the ozone catalytic filler (242) in the catalytic zone (24) is 25% to 45%.
An ozone flotation process for combined sewer overflow sewage as described in claim 1 is characterized in that: a reagent dosing unit (1) is provided, the reagent dosing unit (1) comprises a coagulant solution barrel (11) and a coagulant aid solution barrel (12), the coagulant solution barrel (11) and the coagulant aid solution barrel (12) are respectively connected to the reaction zone (21) through a dosing pipe (14), and a diaphragm metering pump (13) is installed on the dosing pipe (14).
The ozone flotation process for combined sewer overflow sewage according to claim 1 is characterized in that: a main reaction container (2) is provided, and a first stainless steel baffle (7), a baffle (8) and a second stainless steel baffle (71) are fixed in the main reaction container (2) from left to right in sequence, and the first stainless steel baffle (7), the baffle (8) and the second stainless steel baffle (71) divide the main reaction container (2) into a reaction zone (21), a contact zone (22), a separation zone (23) and a catalytic zone (24).
The ozone flotation treatment process for combined sewer overflow sewage according to claim 1 is characterized in that: an ozone generating unit (3) is provided, the ozone generating unit (3) comprises an ozone generator (31), the ozone concentration generated by the ozone generator (31) is 90-135 mg/L, the ozone is divided into two paths and respectively introduced into the first titanium aeration plate (211) and the dissolved air releaser (221), and the flow ratio of the two parts of ozone gas is 1:1 to 1:2.
An ozone flotation treatment process for combined sewer overflow sewage as described in claim 1, characterized in that: a residual ozone treatment unit (5) is provided, the residual ozone treatment unit (5) comprising a rotary fan (16) and at least one second titanium aeration plate (241) arranged at the bottom of the catalytic zone (24), the air inlet of the rotary fan (16) is connected to the separation zone (23), and the air outlet of the rotary fan (16) is connected to the second titanium aeration plate (241).
The ozone flotation treatment process for combined sewer overflow sewage as described in claim 1 is characterized in that a chain scraper (231) is provided at the top of the separation zone (23), and a mud discharge pipe (232) with inclined plates on both sides is provided at the bottom of the separation zone (23).
An ozone flotation treatment process for combined sewer overflow sewage as described in claim 6 is characterized in that: a gas-liquid mixing pump (33) and a dissolved air tank (32) are provided, the gas inlet of the gas-liquid mixing pump (33) is connected to the ozone generator (31), the liquid inlet of the gas-liquid mixing pump (33) is connected to the catalytic zone (24), the outlet of the gas-liquid mixing pump (33) is connected to the inlet of the dissolved air tank (32), and the outlet of the dissolved air tank (32) is connected to the dissolved air releaser (221).
The ozone flotation treatment process for combined sewer overflow sewage according to claim 9, characterized in that the gas-liquid ratio in the gas-liquid mixing pump (33) is 1:9-1:10.