Waste gas treatment method and system

Abstract

The invention relates to a waste gas treatment method and system. The method comprises the following steps: firstly, guiding collected waste gas into an ultraviolet decomposition unit; then, in the ultraviolet decomposition unit, the generated ultraviolet light primarily decomposes pollutants in the waste gas, meanwhile, the ultraviolet light excites oxygen in the waste gas to generate ozone, and the ozone further oxidizes and decomposes the pollutants; and finally, introducing the obtained gas containing the residual pollutants and the ozone into the biological filter unit, and enhancing the degradation capability of the biological filler filled in the biological filter unit by the ozone so as to decompose the residual pollutants. According to the embodiment of the invention, pollutants in waste gas can be primarily decomposed by ultraviolet light and ozone generated by the ultraviolet decomposition unit, so that the inhibition effect of too high pollutants difficult to biochemically degrade on microorganisms is avoided, and ozone in the biological filter unit can optimize a biological filler structure and change metabolic characteristics and community structures of the microorganisms; the operation performance of the biological filter unit can be effectively promoted, and the waste gas treatment effect is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of waste gas treatment, and particularly relates to a waste gas treatment method and system. Background Art

[0002] With the rapid development of modern industry, the emissions of waste gas generated by various industrial production activities are increasing day by day. Among them, the waste gas components such as volatile organic compounds (VOCs) and industrial toxic gases are complex, posing a serious threat to the atmospheric environment, ecological balance and human health.

[0003] At present, in the existing waste gas treatment technologies, the ultraviolet / ozone treatment method has certain limitations. When using ultraviolet / ozone alone for waste gas treatment, first of all, the treatment effect is not thorough. Many chemical bonds in the waste gas are difficult to be completely broken and recombined. In the actual treatment process, usually only part of the chemical bonds can be broken, and then oxygen atoms are added to cause acidification or alcoholization reactions of the waste gas components, resulting in the concentration of volatile organic compounds (VOCs) in the treated waste gas being higher than that at the waste gas inlet before treatment, and the ideal waste gas purification effect cannot be achieved. Secondly, this method is prone to cause secondary pollution. If the reaction conditions cannot be effectively controlled during the treatment process, a large amount of ozone O3 will be generated and directly discharged into the atmosphere, thus causing new pollution to the environment.

[0004] At the same time, the biological filter treatment method also has certain limitations in the field of waste gas treatment. A biological filter is a process for effectively degrading organic wastewater and waste gas. Microorganisms reproduce on the surface of the filter material to form a biofilm, and use the organic matter in the wastewater or waste gas as a nutrient source to complete their own growth and metabolism. The biofilm is composed of various microorganisms. When the biological filter treatment method is used to treat waste gas containing poorly soluble organic matter, due to the complex molecular structure and stable chemical properties of such organic matter, the mass transfer in the biodegradation process is blocked, and it is difficult for microorganisms to fully contact and decompose these substances. Even if the microorganisms have a certain degradation ability, due to insufficient contact with the substances, their metabolic activity cannot be fully exerted, and finally the treatment effect of the biological process on waste gas containing poorly soluble organic matter is greatly reduced, and it is difficult to meet the ideal purification standard.

[0005] In summary, both the ultraviolet / ozone treatment method and the biological filter treatment method cannot completely treat waste gas and are difficult to meet the discharge standards. Summary of the Invention

[0006] Based on this, it is necessary to provide a waste gas treatment method that can effectively promote the operation performance of the biological filter unit and ensure the waste gas treatment effect.

[0007] Based on this, it is necessary to provide a waste gas treatment system that can effectively promote the operation performance of the biological filter unit and ensure the waste gas treatment effect.

[0008] To solve the above technical problems, the embodiments of the present invention adopt the following technical solutions: An exhaust gas treatment method, comprising the following steps:

[0009] S10: Introduce the collected exhaust gas into the ultraviolet decomposition unit;

[0010] S20: Inside the ultraviolet decomposition unit, the generated ultraviolet light preliminarily decomposes the pollutants in the exhaust gas. At the same time, the ultraviolet light excites the oxygen in the exhaust gas to generate ozone, and the ozone further oxidizes and decomposes the pollutants;

[0011] S30: Introduce the gas containing residual pollutants and ozone obtained after the treatment in step S20 into the biological filter unit. The ozone enhances the degradation ability of the biological packing filled inside the biological filter unit, thereby efficiently decomposing the residual pollutants.

[0012] In one embodiment, the collected exhaust gas is introduced into the ultraviolet decomposition unit after removing particulate impurities in the exhaust gas through a filtering unit.

[0013] In one embodiment, the exhaust gas is a mixed gas containing at least volatile organic compounds and chlorobenzene compounds.

[0014] On the other hand, to solve the above further technical problems to be solved, the embodiments of the present invention also provide an exhaust gas treatment system. The system includes an ultraviolet decomposition unit and a biological filter unit. The biological filter unit includes a pool body with spraying liquid at the bottom, and a porous supporting layer, a biological packing layer, a spraying device, and an exhaust pipe are sequentially arranged above the pool body. One end of the ultraviolet decomposition unit is connected to an air supply pipe, and the other end is connected to above the liquid level of the spraying liquid in the pool body. The bottom of the pool body is also connected to the spraying device through a water pump.

[0015] In one embodiment, the ultraviolet decomposition unit is an ultraviolet decomposition chamber with ultraviolet lamps inside. The ultraviolet decomposition chamber is respectively connected to the pool body and the air supply pipe, and a fan is also installed on the air supply pipe connected to the ultraviolet decomposition chamber.

[0016] In one embodiment, the exhaust gas treatment system further includes a filtering unit. The filtering unit is connected to the ultraviolet decomposition unit through an air supply pipe, and the filtering unit is used to remove particulate impurities in the exhaust gas and then introduce it into the ultraviolet decomposition unit.

[0017] In one embodiment, the biological packing layer is filled with biological filter materials, and the biological filter materials include activated carbon, ceramsite, volcanic rock, coconut shell, polyhedron balls, and gravel.

[0018] In one embodiment, the pool body is made of one of the materials of fiberglass, carbon steel, or plastic.

[0019] Adopting the above technical solution, the embodiments of the present invention have at least the following beneficial effects: In the embodiments of the present invention, the above method is adopted. First, the waste gas is introduced into the ultraviolet decomposition unit for pretreatment. This process effectively reduces the amount of pollutants entering the biological filter unit, thereby reducing the treatment load of the biological system, which helps to maintain the stable operation of the biological filter unit. Specifically, the ultraviolet light generated by the ultraviolet decomposition unit will initially decompose the pollutants in the waste gas. At the same time, the ultraviolet light excites the oxygen in the waste gas to generate ozone, and ozone further oxidizes and decomposes the pollutants with its strong oxidizing property, converting macromolecular organic substances into small molecule intermediate products, thereby improving the biodegradability of the pollutants. In this way, a part of the pollutants with poor biodegradability (such as chlorobenzene compounds) is removed, the inlet concentration of the subsequent biological filter unit is reduced, and the inhibitory effect of excessive pollutants with poor biodegradability on microorganisms is avoided. Then, the gas containing residual pollutants and ozone is introduced into the biological filter unit, and water is sprayed onto the biological packing in the biological filter unit to further make the gas containing residual pollutants and ozone fully contact with the biological packing. It should be noted that ozone can play multiple roles in the biological filter unit: the strong oxidizing property of ozone can selectively degrade viscous substances such as polysaccharides and proteins in the outer layer of EPS (extracellular polymer) of the biofilm, thereby reducing the biofilm thickness and increasing the contact area between pollutants and microorganisms; in addition, ozone can also oxidize and decompose the dead cells and metabolic residues that have accumulated excessively in the biofilm, prevent the biological packing from being blocked, and further optimize the specific surface area of the biological packing, improving the mass transfer efficiency of pollutants with poor biodegradability and nutrients (such as N, P, etc.) in the biofilm; in addition, ozone can also optimize the microbial community structure and metabolic characteristics, improving its degradation efficiency of pollutants; ozone enhances the degradation ability of the biological packing filled inside the biological filter unit, thereby efficiently decomposing residual pollutants. In summary, the waste gas treatment method provided by the embodiments of the present invention can effectively promote the operation performance of the biological filter unit through the synergistic biological treatment of ultraviolet / ozone, ensuring the waste gas treatment effect. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a schematic flow chart of an optional embodiment of the waste gas treatment method of the present invention;

[0022] Figure 2 It is a schematic structural diagram of an optional embodiment of the waste gas treatment system of the present invention. Detailed Embodiments

[0023] It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention may be combined with each other. The following will further describe the technical solutions of the present invention with reference to the accompanying drawings of the embodiments of the present invention. The present invention is not limited to the following specific embodiments.

[0024] It should be understood that the same or similar reference numerals in the accompanying drawings of the embodiments correspond to the same or similar components. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "rear", "left", "right", "top", "bottom", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the accompanying drawings are only for illustrative purposes and should not be construed as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0025] In one embodiment, as Figure 1 shown, a waste gas treatment method includes the following steps:

[0026] S10: Introduce the collected waste gas into the ultraviolet decomposition unit;

[0027] S20: In the ultraviolet decomposition unit, the generated ultraviolet light preliminarily decomposes the pollutants in the waste gas. At the same time, the ultraviolet light excites the oxygen in the waste gas to generate ozone, and the ozone further oxidizes and decomposes the pollutants;

[0028] S30: Introduce the gas containing residual pollutants and ozone obtained after the treatment in step S20 into the biological filter unit. The ozone enhances the degradation ability of the biological packing filled inside the biological filter unit, so as to efficiently decompose the residual pollutants.

[0029] Compared with the prior art, the present invention has at least the following advantages: In the embodiment of the present invention, the above method is adopted. First, the waste gas is introduced into the ultraviolet decomposition unit for pretreatment. This process effectively reduces the amount of pollutants entering the biological filter unit, thereby reducing the treatment load of the biological system, which helps to maintain the stable operation of the biological filter unit. Specifically, the ultraviolet light generated by the ultraviolet decomposition unit preliminarily decomposes the pollutants in the waste gas. At the same time, the ultraviolet light excites the oxygen in the waste gas to generate ozone, and the ozone further oxidizes and decomposes the pollutants with its strong oxidizing property, converting the macromolecular organic matter into small-molecule intermediate products, thereby improving the biodegradability of the pollutants. In this way, a part of the hardly biodegradable pollutants (such as chlorobenzene compounds) can be removed, reducing the inlet concentration of the subsequent biological filter unit and avoiding the inhibitory effect of excessive hardly biodegradable pollutants on microorganisms. Then, the gas containing residual pollutants and ozone obtained is introduced into the biological filter unit, and water is sprayed onto the biological packing in the biological filter unit to further make the gas containing residual pollutants and ozone fully contact with the biological packing. The ozone enhances the degradation ability of the biological packing filled inside the biological filter unit, thereby efficiently decomposing the residual pollutants. In summary, the waste gas treatment method provided by the embodiment of the present invention can effectively promote the operation performance of the biological filter unit through the synergistic biological treatment of ultraviolet / ozone, ensuring the waste gas treatment effect.

[0030] It is worth noting that ozone can play multiple roles in the biological filter unit: The strong oxidizing property of ozone can selectively degrade viscous substances such as polysaccharides and proteins in the outer layer EPS (extracellular polymer) of the biofilm, thereby reducing the biofilm thickness and increasing the contact area between pollutants and microorganisms; In addition, ozone can also oxidize and decompose the dead cells and metabolic residues that have accumulated excessively in the biofilm, prevent the biological packing from being blocked, and further optimize the specific surface area of the biological packing, improving the mass transfer efficiency of hardly biodegradable pollutants and nutrients (such as N, P, etc.) in the biofilm; In addition, ozone can also optimize the microbial community structure and metabolic characteristics, improving its degradation efficiency of pollutants.

[0031] In one embodiment, as Figure 1 shown, the collected waste gas is introduced into the ultraviolet decomposition unit after removing particulate impurities in the waste gas through the filtration unit. In this embodiment, by removing the particulate impurities in the waste gas in the filtration unit before introducing the waste gas into the ultraviolet decomposition unit, it is ensured that when the waste gas enters the biological filter unit, the growth of the biofilm and the metabolic activities of microorganisms will not be interfered by the presence of particulate matter, which helps to maintain the stable operation of the biological filter unit and improve the efficiency of the subsequent biodegradation process.

[0032] In one embodiment, as Figure 1As shown, the waste gas is a mixed gas containing at least volatile organic compounds and chlorobenzene compounds. In this embodiment, the ultraviolet decomposition unit can break the chemical bonds of volatile organic compounds (VOCs) and chlorobenzene compounds to generate intermediate products, and ozone further oxidizes and degrades the intermediate products. Finally, through the microbial metabolism and transformation of the biological filter unit, the pollutants are completely decomposed into harmless substances.

[0033] On the other hand, in combination with Figure 2 As shown, an embodiment of the present invention further provides a waste gas treatment system. The system includes an ultraviolet decomposition unit 1 and a biological filter unit 3. The biological filter unit 3 includes a pool body 31 with a spray liquid 30 at the bottom, and a porous support layer 32, a biological filler layer 33, a spray device 34, and an exhaust pipe 35 are sequentially arranged above the pool body 31. One end of the ultraviolet decomposition unit 1 is connected to an air supply pipe 2, and the other end is connected above the liquid level of the spray liquid 30 in the pool body 31. The bottom of the pool body 31 is also connected to the spray device 34 through a water pump 36.

[0034] In the embodiment of the present invention, the waste gas is introduced into the ultraviolet decomposition unit 1 through the air supply pipe 2 for pretreatment. The ultraviolet light generated in the ultraviolet decomposition unit 1 will initially decompose the pollutants in the waste gas. At the same time, the ultraviolet light excites the oxygen in the waste gas to generate ozone, and the ozone further oxidizes and decomposes the pollutants with its strong oxidizing property. Then, the gas containing residual pollutants and ozone is introduced into the biological filter unit 3. The gas will rise from the pool body 31 through the porous support layer 32 to the biological filler layer 33. At the same time, the water pump 36 pumps the spray liquid 30 to the spray device 34, so that the spray device 34 sprays water to the biological filler layer 33, further enabling the gas containing residual pollutants and ozone to fully contact the biological fillers filled in the biological filler layer 33. Ozone can enhance the degradation ability of the biological fillers, and thus can efficiently decompose the residual pollutants. Subsequently, the purified gas is discharged from the exhaust pipe 35. In summary, the waste gas treatment system provided by the embodiment of the present invention can effectively promote the operation performance of the biological filter unit through ultraviolet / ozone synergistic biological treatment, and ensure the waste gas treatment effect.

[0035] In one embodiment, in combination with Figure 2 As shown, the ultraviolet decomposition unit 1 is an ultraviolet decomposition chamber 11 with an ultraviolet lamp 10 installed inside. The ultraviolet decomposition chamber 11 is respectively connected to the pool body 31 and the air supply pipe 2. The air supply pipe 2 connected to the ultraviolet decomposition chamber 11 is also equipped with a fan 12. In this embodiment, the ultraviolet decomposition unit 1 is an ultraviolet decomposition chamber 11 with a closed cavity. An ultraviolet lamp 10 is installed inside the ultraviolet decomposition chamber 11. The fan 12 pumps the waste gas to the ultraviolet decomposition chamber 11 through the air supply pipe 2 for ultraviolet photolysis, and thus can conveniently perform pretreatment on the waste gas.

[0036] In one embodiment, in combination with Figure 2As shown, the waste gas treatment system further includes a filtering unit 4, which is connected to the ultraviolet decomposition unit 1 through an air supply pipe 2. The filtering unit 4 is used to remove particulate impurities in the waste gas and then introduce it into the ultraviolet decomposition unit 1. In this embodiment, by further setting the filtering unit 4, the filtering unit 4 is connected to the ultraviolet decomposition unit 1 through the air supply pipe 2, so that before introducing the waste gas into the ultraviolet decomposition unit 1, the particulate impurities in the waste gas are first removed in the filtering unit 4, thereby ensuring that when the waste gas enters the biological filter unit 3, the growth of the biofilm and the metabolic activities of microorganisms will not be interfered by the presence of particulate matter, which helps to maintain the stable operation of the biological filter unit 3 and improve the efficiency of the subsequent biodegradation process.

[0037] In one embodiment, in combination with Figure 2 As shown, the biological packing layer 33 is filled with biological filter media, and the biological filter media includes activated carbon, ceramsite, volcanic rock, coconut shell, polyhedron balls and gravel. In this embodiment, by using the biological filter media with the above components, the removal efficiency of recalcitrant biodegradable pollutants can be effectively improved.

[0038] In one embodiment, in combination with Figure 2 As shown, the pool body 31 is made of one of fiberglass, carbon steel or plastic. In this embodiment, the pool body 31 is made of the above materials, with stable structural performance, effectively ensuring the effective operation of the system.

[0039] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A waste gas treatment method, characterized in that, The method includes the following steps: S10: Introduce the collected waste gas into the ultraviolet decomposition unit; S20: Inside the ultraviolet decomposition unit, the generated ultraviolet light preliminarily decomposes the pollutants in the waste gas. Meanwhile, the ultraviolet light excites the oxygen in the waste gas to generate ozone, and the ozone further oxidizes and decomposes the pollutants; S30: The gas containing residual pollutants and ozone obtained after being treated in step S20 is introduced into the biological filter unit. The ozone enhances the degradation ability of the biological packing material filled inside the biological filter unit, thereby efficiently decomposing the residual pollutants.

2. The waste gas treatment method according to claim 1, characterized in that The collected waste gas is introduced into the ultraviolet decomposition unit after passing through the filter unit to remove particulate impurities in the waste gas.

3. The waste gas treatment method according to claim 1, characterized in that, The waste gas is a mixed gas containing at least volatile organic compounds and chlorobenzene compounds.

4. An exhaust gas treatment system, characterized in that, It includes an ultraviolet decomposition unit and a biological filter unit. The biological filter unit includes a pool body with spraying liquid at the bottom, and a porous support layer, a biological packing layer, a spraying device, and an exhaust pipe are sequentially arranged above the pool body. One end of the ultraviolet decomposition unit is connected to an air supply pipe, and the other end is connected above the liquid level of the spraying liquid in the pool body. The bottom of the pool body is also connected to the spraying device through a water pump.

5. The exhaust gas treatment system according to claim 4, characterized in that, The ultraviolet decomposition unit is an ultraviolet decomposition chamber with ultraviolet lamps installed inside. The ultraviolet decomposition chamber is respectively connected to the pool body and the air supply pipe, and a fan is also installed on the air supply pipe connected to the ultraviolet decomposition chamber.

6. The waste gas treatment system according to claim 4, characterized in that, The system further includes a filter unit. The filter unit is connected to the ultraviolet decomposition unit through an air supply pipe. The filter unit is used to remove particulate impurities in the waste gas and then introduce it into the ultraviolet decomposition unit.

7. The waste gas treatment system according to any one of claims 4-6, characterized in that, The biological packing layer is filled with biological filter materials. The biological filter materials include activated carbon, ceramsite, volcanic rock, coconut shell, polyhedron balls, and gravel.

8. The waste gas treatment system according to any one of claims 4-6, characterized in that, The pool body is made of one of the materials of fiberglass, carbon steel, or plastic.

Images