Photocatalytic ozonation wastewater treatment system

Abstract

The utility model discloses a photocatalytic ozonation wastewater treatment system which comprises an ozone generator and a wastewater storage tank, one side of the ozone generator is connected with an ozone concentration detector A, one side of the ozone concentration detector A is connected with a gas path system, one side of the gas path system is connected with a photocatalytic ozonation reactor, and the other side of the photocatalytic ozonation reactor is connected with a wastewater storage tank. The top of the photocatalytic ozonation reactor is connected with an ozone concentration detector B, one side of the photocatalytic ozonation reactor is connected with an effluent storage tank, one side of the wastewater storage tank is connected with a water pump, one side of the water pump is connected with a liquid path system, and the liquid path system is connected with the photocatalytic ozonation reactor; the photocatalytic ozonation reactor comprises an aeration head, a light source, an air inlet, a water inlet, an air outlet and a water outlet, the core of the system is the photocatalytic ozonation tubular reactor, the light source of the reactor is designed into a double-layer quartz lamp tube which is arranged in the tubular reactor, and the efficient utilization of the light source is realized.

Description

Technical Field

[0001] The utility model relates to the field of wastewater treatment, in particular to a photocatalytic ozone oxidation wastewater treatment system. Background Art

[0002] Ozone oxidation wastewater treatment technology belongs to the advanced oxidation process technology in industrial wastewater treatment process. It is usually applied to the effluent section of wastewater discharged from factories after biochemical process technology. It mainly targets organic pollutants that are difficult to treat and difficult to degrade by biochemical process technology, and achieves COD discharge in wastewater that meets the standard. Advanced oxidation technology is to use oxidants to treat wastewater, oxidizing organic pollutants in wastewater that are difficult to degrade and difficult to degrade into non-toxic and harmless gases such as -CO2 and N2 and discharging them into the environment. The disadvantage is that the oxidizing property is not strong, it cannot be completely mineralized or the removal rate of organic pollutants cannot meet the urban sewage discharge standard. The advantage is that the engineering equipment is simple and there is no secondary pollution. Since ozone oxidation technology uses ozone as an oxidant, it greatly reduces costs and does not produce hazardous waste, and is widely favored by the wastewater treatment industry.

[0003] The process technology solutions currently used in urban sewage treatment plants usually use a mixture of biological treatment technology, chemical technology, membrane technology, advanced oxidation technology and evaporation desalination technology. Among them, advanced oxidation technology belongs to the deep treatment technology of wastewater. Other treatment technologies can hardly reduce the content of organic pollutants in wastewater after treating high-concentration organic pollutants to the level of 500-1000mg / L. The existing catalytic ozone oxidation technology can achieve a catalytic oxidation removal rate of about 20% for high-concentration and difficult-to-degrade organic pollutants in pharmaceutical wastewater, petrochemical wastewater, printing and dyeing wastewater and industrial park wastewater, achieving a certain degree of deep treatment effect of wastewater. The effluent COD is still very high and it is difficult to reach the urban sewage discharge standard COD below 50mg / L. The oxidizing property of the wastewater after the advanced oxidation unit will have a serious impact on the subsequent membrane treatment process and salt reduction process.

[0004] In view of this, the existing problems are studied and improved, and a photocatalytic ozone oxidation wastewater treatment system is provided. The new photocatalytic ozone oxidation technology is used to replace the traditional advanced oxidation technology to solve the wastewater treatment problems that are difficult to solve with the traditional advanced oxidation technology and the impact on the subsequent treatment process. The main focus is on the use of photocatalytic ozone oxidation technology to treat antibiotic wastewater discharged from the pharmaceutical industry, and the COD content can be at the level of tens, hundreds or thousands of mg / L. This device has a wide range of applications and can achieve the treatment of organic pollutants in a large concentration range and the treatment of highly complex and high-salt wastewater, including pharmaceutical wastewater, petrochemical wastewater, printing and dyeing wastewater, industrial park wastewater and other urban wastewater treatment fields that need to be solved urgently. The purpose is to achieve the purpose of solving problems and improving practical value through this technology. Utility Model Content

[0005] The utility model aims to solve the shortcomings in the prior art and proposes a photocatalytic ozone oxidation wastewater treatment system.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a photocatalytic ozone oxidation wastewater treatment system, comprising an ozone generator and a wastewater storage tank, one side of the ozone generator is connected to an ozone concentration detector A, one side of the ozone concentration detector A is connected to an air path system, one side of the air path system is connected to a photocatalytic ozone oxidation reactor, the top of the photocatalytic ozone oxidation reactor is connected to an ozone concentration detector B, one side of the photocatalytic ozone oxidation reactor is connected to a water outlet storage tank, one side of the wastewater storage tank is connected to a water pump, one side of the water pump is connected to a liquid path system, the liquid path system is connected to the photocatalytic ozone oxidation reactor, and the photocatalytic ozone oxidation reactor comprises an aeration head, a light source, an air inlet, a water inlet, an air outlet and a water outlet.

[0007] As a further description of the above technical solution:

[0008] The ozone concentration detector A is fixedly connected between the ozone generator and the gas circuit system, one end of the gas circuit system is connected to the air inlet, and the photocatalytic ozone oxidation reactor is a tubular reactor.

[0009] As a further description of the above technical solution:

[0010] The wastewater storage tank is arranged on one side of the ozone generator, the water pump is fixedly connected between the wastewater storage tank and the liquid circuit system, the liquid circuit system is connected to the water inlet, the gas circuit system and the liquid circuit system are made of stainless steel pipes, and are connected in sequence to a needle valve, a back pressure valve, a pressure display, a mass flow controller, a check valve and a ball valve.

[0011] As a further description of the above technical solution:

[0012] The ozone concentration detector B is fixedly connected to the air outlet, the water outlet storage box is fixedly connected to the water outlet, and the number of the photocatalytic ozone oxidation reactors is several.

[0013] As a further description of the above technical solution:

[0014] The aeration head is fixedly installed inside the photocatalytic ozone oxidation reactor, and the air inlet and the water inlet are integrally connected to the outer wall of the photocatalytic ozone oxidation reactor, and the air inlet is connected to the aeration head. One end of the aeration head has a thread and is directly screwed into the threaded hole pre-opened at the steel pipe mouth of the air inlet in the reactor by screw connection. Filters matching the size of the catalyst are installed at the air inlet and the water inlet to fix the catalyst in the reactor to prevent the catalyst from flowing out into the pipeline.

[0015] As a further description of the above technical solution:

[0016] The light source is fixedly installed on the top of the photocatalytic ozone oxidation reactor, the air outlet and the water outlet are integrally connected to the outer wall of the photocatalytic ozone oxidation reactor, the air outlet and the water outlet are arranged above the air inlet and the water inlet, the light source is a lamp tube light source, the lamp tube is a double-layer tube, the inner part is a light-emitting lamp tube, the outer quartz part is immersed in the wastewater solution, the lamp cap is at the upper end of the reactor and is sealed with an O-ring. The number of light sources is several lamp tubes, the part of the lamp tube immersed in the wastewater solution accounts for about 80% of the length of the reactor and between 30% and 50% of the inner diameter of the reactor. In addition, the space occupied by the lamp tube in the reactor may not be limited to this data, depending on the effect of different reaction systems. The air outlet and the water outlet are installed with filters that match the size of the catalyst to fix the catalyst in the reactor to prevent the catalyst from flowing out into the pipeline.

[0017] The utility model has the following beneficial effects:

[0018] In the utility model, the core of the system is a photocatalytic ozone oxidation tubular reactor. The reactor designs the light source as a double-layer quartz lamp tube and places it inside the tubular reactor, thereby realizing efficient use of the light source. An ozone aeration head is designed inside the reactor to produce micron-sized ozone micro-bead bubbles, thereby realizing full mixing of the ozone raw gas and the wastewater solution. The photocatalyst is dispersed in the above-mentioned gas-liquid raw material mixture, and is subjected to light to undergo a photocatalytic reaction to remove COD in the wastewater. The technical core of the system also lies in the fact that the tubular reactor can form a multi-stage and multi-segment array reactor, which is convenient for achieving near-zero emission of COD removal rate for highly complex and high-concentration wastewater. In addition, the photocatalytic ozone oxidation technology is a novel wastewater treatment technology, which has the near-zero emission technology for wastewater COD of highly complex, high-concentration, and difficult-to-degrade organic pollutants that is difficult to achieve with traditional oxidation technology.

[0019] Compared with traditional ozone oxidation technology, photocatalytic ozone oxidation technology has the function of efficiently degrading and removing organic pollutants. For highly complex and difficult-to-degrade wastewater, it can deeply oxidize and mineralize organic pollutants into non-toxic and harmless gases such as CO2 and N2 and discharge them into the environment. The core technology of this device is the photocatalytic ozone oxidation reactor and process flow. After experimental testing, the biochemical effluent of Xinjiang Chuan Ning Pharmaceutical Wastewater was treated with TiO2 (P25) photocatalyst and 254nm ultraviolet light. Photocatalytic ozone oxidation has a significant effect on removing COD, and can achieve efficient removal of COD in high-salt and high-complexity pharmaceutical wastewater, reaching near-zero emission standards. This device is also suitable for COD removal in petrochemical wastewater, printing and dyeing wastewater and industrial park wastewater. It has a wide range of applications and can treat factory wastewater with high complexity and difficult-to-remove COD with daily emissions of tons, hundreds of tons, thousands of tons and tens of thousands of tons. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of a photocatalytic ozone oxidation wastewater treatment process of a photocatalytic ozone oxidation wastewater treatment system proposed in the utility model;

[0021] Figure 2 A schematic diagram of a photocatalytic ozone oxidation reactor of a photocatalytic ozone oxidation wastewater treatment system proposed in the utility model;

[0022] Figure 3 A schematic diagram of a multi-stage tubular reactor of a photocatalytic ozone oxidation reaction system of a photocatalytic ozone oxidation wastewater treatment system proposed by the utility model;

[0023] Figure 4 This is a schematic diagram of a multi-stage and multi-segment array type tubular reactor of a photocatalytic ozone oxidation reaction system of a photocatalytic ozone oxidation wastewater treatment system proposed by the utility model.

[0024] Legend:

[0025] 1. Ozone generator; 2. Ozone concentration detector A; 3. Gas circuit system; 4. Photocatalytic ozone oxidation reactor; 5. Ozone concentration detector B; 6. Effluent storage tank; 7. Wastewater storage tank; 8. Water pump; 9. Liquid circuit system; 41. Aeration head; 42. Light source; 43. Air inlet; 44. Water inlet; 45. Air outlet; 46. Water outlet. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, which are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present utility model; the terms "first", "second" and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance. In addition, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0028] Reference Figure 1-4 The utility model provides an embodiment: a photocatalytic ozone oxidation wastewater treatment system, comprising an ozone generator 1 and a wastewater storage tank 7, one side of the ozone generator 1 is connected to an ozone concentration detector A2, one side of the ozone concentration detector A2 is connected to an air path system 3, one side of the air path system 3 is connected to a photocatalytic ozone oxidation reactor 4, the top of the photocatalytic ozone oxidation reactor 4 is connected to an ozone concentration detector B5, one side of the photocatalytic ozone oxidation reactor 4 is connected to a water outlet storage tank 6, one side of the wastewater storage tank 7 is connected to a water pump 8, one side of the water pump 8 is connected to a liquid path system 9, the liquid path system 9 is connected to the photocatalytic ozone oxidation reactor 4, and the photocatalytic ozone oxidation reactor 4 comprises an aeration head 41, a light source 42, an air inlet 43, a water inlet 44, an air outlet 45 and a water outlet 46.

[0029] Specifically, photocatalytic ozone oxidation technology is used to remove COD from wastewater discharged from various types of factories. Under the irradiation of light, photocatalysts catalyze ozone to produce highly active oxidizing species, deeply oxidizing and mineralizing highly complex and difficult-to-degrade organic pollutants into environmentally friendly gases such as CO2 and N2 and discharging them into the air. This device technology is a highly efficient green environmental protection technology. The reaction conditions of room temperature catalysis using light sources as energy sources greatly reduce energy consumption. The gas produced after the reaction using ozone as an oxidizing agent is oxygen, which is green and environmentally friendly without secondary pollution.

[0030] In the present invention, the ozone concentration detector A2 is fixedly connected between the ozone generator 1 and the gas circuit system 3, one end of the gas circuit system 3 is connected to the air inlet 43, and the photocatalytic ozone oxidation reactor 4 is a tubular reactor.

[0031] Specifically, the technical core of this device is a photocatalytic ozone oxidation reactor. The reactor is designed as a tubular reactor with an air inlet at the lower end for transporting ozone into the reactor. The aeration head connected to the air inlet inside the reactor is used to disperse the ozone into micron-level micro-bead bubbles. A large number of ozone micro-bead bubbles in the wastewater solution rise from the lower end of the reactor to the top of the reactor. The whole process achieves full mixing of ozone and wastewater, and photocatalytic reaction is carried out on the surface of the photocatalyst to remove COD. The excess ozone gas that does not participate in the reaction and the CO2 and N2 generated in the reaction are discharged from the upper outlet of the reactor. The lower end of the reactor air inlet is designed with a water inlet for transporting wastewater into the reactor. The wastewater entering the reactor is immediately mixed with the ozone micro-bead bubbles to participate in the photocatalytic reaction. The wastewater that has completed the reaction is discharged from the water outlet at the upper end of the reactor.

[0032] Furthermore, the wastewater storage tank 7 is arranged on one side of the ozone generator 1, the water pump 8 is fixedly connected between the wastewater storage tank 7 and the liquid circuit system 9, the liquid circuit system 9 is connected to the water inlet 44, and the gas circuit system 3 and the liquid circuit system 9 are made of stainless steel pipes, which are connected in sequence with a needle valve, a back pressure valve, a pressure display, a mass flow controller, a one-way valve and a ball valve.

[0033] Specifically, the gas circuit system of the device can realize precise control of the flow rate of gas raw materials and pressure display and control, and is used for the injection flow pressure control of ozone raw gas, and an ozone concentration detector is provided at the outlet of the ozone generator to detect and control the concentration of ozone raw gas. The liquid circuit system can realize precise control of the injection flow rate of wastewater raw materials and pressure display and control, and the wastewater storage tank is connected to a water pump to continuously provide wastewater raw materials for the reactor.

[0034] Furthermore, the ozone concentration detector B5 is fixedly connected to the air outlet 45, the water outlet storage box 6 is fixedly connected to the water outlet 46, and the number of the photocatalytic ozone oxidation reactors 4 can be one or more.

[0035] Specifically, the ozone raw gas and the wastewater raw liquid participate in the reaction in the reactor. After the reaction, the gas enters the ozone concentration detector from the gas outlet and is then discharged into the air. The ozone concentration detector at the reactor outlet is equipped with an ozone destructor. While detecting the ozone concentration after the reaction, the excess ozone that does not participate in the reaction is processed into oxygen and discharged into the air. After the wastewater raw material participates in the reaction in the photocatalytic ozone oxidation reactor, the COD removal rate is close to zero and enters the water outlet storage.

[0036] Furthermore, the aeration head 41 is fixedly installed inside the photocatalytic ozone oxidation reactor 4 , the air inlet 43 and the water inlet 44 are integrally connected to the outer wall of the photocatalytic ozone oxidation reactor 4 , and the air inlet 43 is connected to the aeration head 41 .

[0037] Specifically, the technical core of this device is that the designed lamp-type light source is inserted into the reactor from the top of the reactor. The lamp tube is a double-layer tube in which the inner part is a light-emitting lamp tube, and the outer quartz part is immersed in the wastewater solution. The lamp cap is at the upper end of the reactor and is sealed with an O-ring. The photocatalyst is dispersed in the wastewater solution and fully contacts the ozone and organic pollutants in the wastewater. The mixture of the three surrounds the lamp tube and collects light at a close distance, realizing efficient use of the light source.

[0038] Further, the light source 42 is fixedly mounted on the top of the photocatalytic ozone oxidation reactor 4, the air outlet 45 and the water outlet 46 are integrally connected to the outer wall of the photocatalytic ozone oxidation reactor 4, the air outlet 45 and the water outlet 46 are arranged above the air inlet 43 and the water inlet 44, the light source 42 is a lamp tube light source, the lamp tube is a double-layer tube in which the inner part is a light-emitting lamp tube, the outer quartz part is immersed in the wastewater solution, the lamp cap is at the upper end of the reactor and is sealed with an O-ring. The number of lamp tubes of the light source 42 can be one or more.

[0039] Working principle and usage process:

[0040] The core technology of this device lies in the photocatalytic ozone oxidation reaction system, which connects multiple tubular reactors in series, and the water outlet of the previous reactor enters the water inlet of the next reactor to form a multi-stage tubular reactor, which improves the photocatalytic ozone oxidation technology for wastewater COD treatment effect. According to the complexity of the water sample and the scale of wastewater treatment, the final reaction system can be designed into a multi-stage multi-stage array tubular reactor such as Figure 4 As shown, multiple tubular reactors are connected in parallel at each stage, and the outlet of the previous stage is connected to the inlet of the next stage, finally forming an array of tubular reactors, increasing the wastewater treatment capacity and being applied to large-scale wastewater treatment plants. The photocatalytic ozone oxidation reaction system of this device can flexibly use the number of tubular reactors according to the complexity of the water sample and the scale of wastewater treatment, ensuring the near-zero emission of COD removal rate of highly complex and high-concentration wastewater discharged by various types of factories.

[0041] The key innovative technology of this device is the designed photocatalytic ozone oxidation reaction system. The core of this system is the photocatalytic ozone oxidation tubular reactor. The reactor designs the light source as a double-layer quartz lamp tube placed inside the tubular reactor. The number of lamp tubes can be one or several, realizing the efficient use of the light source. The reactor is designed with an ozone aeration head, which can produce micron-level ozone micro-bead bubbles, realizing the full mixing of ozone raw gas and wastewater solution. The photocatalyst is dispersed in the above-mentioned gas-liquid raw material mixture, and is subjected to light to undergo photocatalytic reaction to remove COD in the wastewater. The photocatalytic ozone oxidation tubular reactor can be an integrated type or a quick-disassembly installation type connection. The innovation of this device includes but is not limited to the disassembly and installation method of the reactor. The technical core of this system is that the tubular reactor can form a multi-stage and multi-segment array reactor, which is convenient for achieving near-zero emission of COD removal rate of highly complex and high-concentration wastewater. In addition, the photocatalytic ozone oxidation technology is a novel wastewater treatment technology, which has the near-zero emission technology of COD in wastewater with highly complex, high-concentration and difficult-to-degrade organic pollutants that is difficult to achieve with traditional oxidation technology.

[0042] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A photocatalytic ozone oxidation wastewater treatment system, comprising an ozone generator (1) and a wastewater storage tank (7), characterized in that: One side of the ozone generator (1) is connected to an ozone concentration detector A (2), one side of the ozone concentration detector A (2) is connected to an air path system (3), one side of the air path system (3) is connected to a photocatalytic ozone oxidation reactor (4), the top of the photocatalytic ozone oxidation reactor (4) is connected to an ozone concentration detector B (5), one side of the photocatalytic ozone oxidation reactor (4) is connected to a water outlet storage tank (6), one side of the wastewater storage tank (7) is connected to a water pump (8), one side of the water pump (8) is connected to a liquid path system (9), the liquid path system (9) is connected to the photocatalytic ozone oxidation reactor (4), and the photocatalytic ozone oxidation reactor (4) comprises an aeration head (41), a light source (42), an air inlet (43), a water inlet (44), an air outlet (45) and a water outlet (46).

2. A photocatalytic ozone oxidation wastewater treatment system according to claim 1, characterized in that: The ozone concentration detector A (2) is fixedly connected between the ozone generator (1) and the gas circuit system (3), one end of the gas circuit system (3) is connected to the air inlet (43), and the photocatalytic ozone oxidation reactor (4) is a tubular reactor.

3. A photocatalytic ozone oxidation wastewater treatment system according to claim 1, characterized in that: The wastewater storage tank (7) is arranged on one side of the ozone generator (1); the water pump (8) is fixedly connected between the wastewater storage tank (7) and the liquid circuit system (9); the liquid circuit system (9) is connected to the water inlet (44); the gas circuit system (3) and the liquid circuit system (9) are made of stainless steel pipes and are connected in sequence to a needle valve, a back pressure valve, a pressure display, a mass flow controller, a check valve and a ball valve.

4. A photocatalytic ozone oxidation wastewater treatment system according to claim 1, characterized in that: The ozone concentration detector B (5) is fixedly connected to the air outlet (45), the water outlet storage box (6) is fixedly connected to the water outlet (46), and the number of the photocatalytic ozone oxidation reactors (4) is several.

5. The photocatalytic ozone oxidation wastewater treatment system according to claim 1, characterized in that: The aeration head (41) is fixedly installed inside the photocatalytic ozone oxidation reactor (4); the air inlet (43) and the water inlet (44) are integrally connected to the outer wall of the photocatalytic ozone oxidation reactor (4); the air inlet (43) is connected to the aeration head (41); one end of the aeration head (41) is threaded and is directly screwed into a threaded hole pre-opened at the steel pipe mouth of the air inlet (43) in the reactor by means of a screw connection; filters matching the size of the catalyst are installed inside the air inlet (43) and the water inlet (44) reactor to fix the catalyst in the reactor to prevent the catalyst from flowing out into the pipeline.

6. A photocatalytic ozone oxidation wastewater treatment system according to claim 1, characterized in that: The light source (42) is fixedly mounted on the top of the photocatalytic ozone oxidation reactor (4); the air outlet (45) and the water outlet (46) are integrally connected to the outer wall of the photocatalytic ozone oxidation reactor (4); the air outlet (45) and the water outlet (46) are arranged above the air inlet (43) and the water inlet (44); the light source (42) is a lamp tube light source; the lamp tube is a double-layer tube, the inner part of which is a light-emitting lamp tube, and the outer quartz part is immersed in the wastewater solution; the lamp cap is at the upper end of the reactor and is sealed with an O-ring; the number of the light sources (42) is a plurality of lamp tubes, the part of the lamp tube immersed in the wastewater solution accounts for about 80% of the length of the reactor and between 30% and 50% of the inner diameter of the reactor; in addition, the space occupied by the lamp tube in the reactor may not be limited to this data, and is determined according to the effects of different reaction systems; the air outlet (45) and the water outlet (46) are installed with filters matching the size of the catalyst inside the reactor to fix the catalyst in the reactor to prevent the catalyst from flowing out into the pipeline.

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