Method for treating ammonia-nitrogen wastewater based on photocatalysis and ozone oxidation coupling

Abstract

The invention relates to a method for treating ammonia-nitrogen wastewater based on photocatalysis and ozonation coupling, and belongs to the technical field of wastewater treatment.The method comprises the following steps that S1, early-stage preparation is conducted on wastewater treatment; s2, photocatalytic ozone oxidation coupling treatment; s3, wastewater effluent treatment; s4, regeneration and recovery of the catalyst; and S5, monitoring the effluent quality of the wastewater. According to the method for treating the ammonia-nitrogen wastewater based on photocatalysis and ozonation coupling, the ammonia-nitrogen wastewater is treated by adopting the wastewater treatment method, so that the degradation efficiency of ammonia nitrogen can be effectively improved, and ammonia nitrogen components in the wastewater can be more effectively removed; in the photocatalytic reaction process, pollutants are decomposed into harmless substances, so that the problem of secondary pollution is avoided; in the ozone oxidation process, ozone can be quickly decomposed, the influence on follow-up treatment facilities is reduced, meanwhile, light energy is utilized in the photocatalytic reaction, the advantages of energy conservation and environmental protection are achieved, and the advantages of efficient degradation, no secondary pollution, energy conservation and environmental protection are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation. Background Art

[0002] Ammonia nitrogen wastewater is a common industrial wastewater, and its treatment has always been an important issue in the field of environmental protection. Traditional ammonia nitrogen wastewater treatment methods include physical treatment, chemical treatment and biological treatment.

[0003] Physical treatment method: mainly removes ammonia nitrogen from wastewater by physical means, such as the stripping method using air or steam to transfer ammonia in wastewater from liquid phase to gas phase, and the adsorption method uses porous materials such as activated carbon and zeolite to adsorb ammonia nitrogen in wastewater. However, physical treatment methods are usually suitable for the preliminary treatment of low-concentration ammonia nitrogen wastewater, and the adsorption materials need to be regenerated or replaced regularly, which is costly. Chemical treatment method: removes ammonia nitrogen from wastewater through chemical reactions, such as the chemical precipitation method adding magnesium salts and phosphates to wastewater to form insoluble magnesium ammonium phosphate precipitates, and the breakpoint chlorination method oxidizes ammonia nitrogen to generate nitrogen gas to escape. However, chemical treatment methods may produce by-products and cause secondary pollution to the environment. Biological treatment method: removes ammonia nitrogen from wastewater by using the metabolism of microorganisms, such as nitrification-denitrification method, short-range nitrification-denitrification method and anaerobic ammonia oxidation method. Biological treatment is one of the most commonly used and economical methods at present, but it requires strict control of reaction conditions and a long treatment time. However, these methods have certain limitations in terms of treatment effect, cost, and ease of operation.

[0004] At present, the research on the treatment of ammonia nitrogen wastewater by coupling photocatalysis and ozone oxidation is still in its infancy. Domestic and foreign scholars are actively exploring issues such as the selection of photocatalysts, the optimization of reaction mechanisms, and the design of coupling processes. In the future, with the continuous advancement of technology and further reduction of costs, the technology of coupling photocatalysis and ozone oxidation to treat ammonia nitrogen wastewater is expected to be more widely used and promoted.

[0005] In summary, the method for treating ammonia nitrogen wastewater based on the coupling of photocatalysis and ozone oxidation has broad application prospects and important research value. Through in-depth research and technological innovation, it is expected to provide a new method for the treatment of ammonia nitrogen wastewater that is efficient, environmentally friendly and economical. Therefore, this application proposes a method for treating ammonia nitrogen wastewater based on the coupling of photocatalysis and ozone oxidation to achieve the above purpose. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a method for treating ammonia nitrogen wastewater based on the coupling of photocatalysis and ozone oxidation, which has the advantages of efficient degradation, no secondary pollution, energy saving and environmental protection, and solves the problem that traditional wastewater treatment methods have certain limitations in treatment effect, cost, ease of operation, etc.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation, comprising the following steps:

[0009] S1. Preliminary preparation for wastewater treatment: perform necessary pretreatment on the original ammonia nitrogen wastewater; prepare the treatment equipment required for wastewater treatment;

[0010] S2. Photocatalytic ozone oxidation coupling treatment: a photocatalyst is arranged in a photocatalytic reactor; ozone gas is generated by an ozone generator and introduced into the photocatalytic reactor through a pipeline; the pretreated ammonia nitrogen wastewater is then introduced into the photocatalytic reactor through a pipeline, and in the photocatalytic reactor, the wastewater is fully contacted with ozone and photocatalyst, and photocatalytic oxidation and ozone oxidation reactions occur;

[0011] S3. Wastewater treatment: After the reaction is completed, the treated wastewater is discharged from the photocatalytic reactor, and necessary subsequent treatment is required for the wastewater during discharge;

[0012] S4. Regeneration and recycling of catalysts: After long-term use, the photocatalyst will be deactivated due to the adsorption of pollutants. At this time, the catalyst needs to be regenerated to restore its activity; for catalysts that cannot be regenerated, they should be properly recycled and treated to avoid secondary pollution to the environment;

[0013] S5. Monitoring of wastewater effluent quality: The effluent quality should be monitored regularly.

[0014] Furthermore, the pretreatment in S1 includes adjusting the pH value and removing suspended matter, and the pretreatment ensures the smooth progress of the subsequent treatment process.

[0015] Furthermore, the treatment equipment in S1 includes a photocatalytic reactor, an ozone generator, pipelines, valves and a control system.

[0016] Furthermore, the photocatalytic reactor needs to have good sealing properties and lighting conditions; the ozone generator is used to generate ozone gas; and the pipeline, valve and control system are used to achieve continuous flow of wastewater and uniform distribution of ozone.

[0017] Furthermore, the catalyst in S2 is titanium dioxide, and the catalyst should be evenly coated on the inner wall of the photocatalytic reactor or on the carrier to ensure that the lighting conditions in the photocatalytic reactor meet the requirements of the photocatalytic reaction. An ultraviolet light source is usually required in the photocatalytic reactor.

[0018] Furthermore, the dosage of ozone in S2 entering the photocatalytic reactor needs to be controlled to ensure that it fully reacts with ammonia nitrogen in the wastewater.

[0019] Furthermore, during the reaction of the wastewater in S2 with ozone and photocatalyst, the photocatalyst generates electron-hole pairs under the irradiation of ultraviolet light, and then generates free radicals with strong oxidizing properties. These free radicals react with ammonia nitrogen in the wastewater and oxidize it into harmless nitrogen or other nitrogen oxides.

[0020] Furthermore, during the reaction of the wastewater in S2 with ozone and photocatalyst, the temperature, pressure and light intensity conditions of the photocatalytic reactor need to be controlled to ensure efficient reaction; the amount of ozone added and the reaction time are adjusted according to the properties of the wastewater and the treatment objectives.

[0021] Furthermore, the subsequent treatment in S3 includes adjusting the pH value and removing residual ozone, and the subsequent treatment ensures that the effluent quality meets the discharge standard.

[0022] Furthermore, the water quality monitoring in S5 includes indicators of ammonia nitrogen concentration, chemical oxygen demand, and pH value.

[0023] Compared with the prior art, the present invention provides a method for treating ammonia nitrogen wastewater based on the coupling of photocatalysis and ozone oxidation, which has the following beneficial effects:

[0024] The method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation can effectively accelerate the degradation efficiency of ammonia nitrogen and more effectively remove the ammonia nitrogen components in the wastewater by adopting the above-mentioned wastewater treatment method to treat ammonia nitrogen wastewater; during the photocatalytic reaction, pollutants are decomposed into harmless substances and no secondary pollution problem will be generated; during the ozone oxidation process, ozone can be quickly decomposed to reduce the impact on subsequent treatment facilities, and at the same time, the photocatalytic reaction utilizes light energy, which has the advantages of energy saving and environmental protection, and achieves the advantages of efficient degradation, no secondary pollution, energy saving and environmental protection, and solves the problem that traditional wastewater treatment methods have certain limitations in treatment effect, cost, ease of operation and other aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention is a process flow chart of a method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of 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.

[0027] See also Figure 1In this embodiment, a method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation comprises the following steps:

[0028] S1. Preliminary preparation for wastewater treatment: perform necessary pretreatment on the original ammonia nitrogen wastewater; prepare the treatment equipment required for wastewater treatment;

[0029] S2. Photocatalytic ozone oxidation coupling treatment: a photocatalyst is arranged in a photocatalytic reactor; ozone gas is generated by an ozone generator and introduced into the photocatalytic reactor through a pipeline; the pretreated ammonia nitrogen wastewater is then introduced into the photocatalytic reactor through a pipeline, and in the photocatalytic reactor, the wastewater is fully contacted with ozone and photocatalyst, and photocatalytic oxidation and ozone oxidation reactions occur;

[0030] S3. Wastewater treatment: After the reaction is completed, the treated wastewater is discharged from the photocatalytic reactor, and necessary subsequent treatment is required for the wastewater during discharge;

[0031] S4. Regeneration and recycling of catalysts: After long-term use, the photocatalyst will be deactivated due to the adsorption of pollutants. At this time, the catalyst needs to be regenerated to restore its activity; for catalysts that cannot be regenerated, they should be properly recycled and treated to avoid secondary pollution to the environment;

[0032] S5. Monitoring of wastewater effluent quality: The effluent quality should be monitored regularly.

[0033] In this embodiment, by adopting the above-mentioned wastewater treatment method to treat ammonia nitrogen wastewater, the degradation efficiency of ammonia nitrogen can be effectively accelerated, and the ammonia nitrogen component in the wastewater can be more effectively removed; during the photocatalytic reaction, pollutants are decomposed into harmless substances and no secondary pollution problems will occur; during the ozone oxidation process, ozone can be quickly decomposed, reducing the impact on subsequent treatment facilities. At the same time, the photocatalytic reaction utilizes light energy, which has the advantages of energy saving and environmental protection, achieving the advantages of efficient degradation, no secondary pollution, and energy saving and environmental protection.

[0034] In this embodiment, the pretreatment in S1 includes adjusting the pH value and removing suspended matter, and the pretreatment ensures the smooth progress of the subsequent treatment process. The treatment equipment in S1 includes a photocatalytic reactor, an ozone generator, pipelines, valves and a control system.

[0035] Specifically, the photocatalytic reactor needs to have good sealing and lighting conditions; the ozone generator is used to generate ozone gas; and the pipes, valves and control systems are used to achieve continuous flow of wastewater and uniform distribution of ozone.

[0036] In this embodiment, the catalyst in S2 is titanium dioxide, and the catalyst should be evenly coated on the inner wall of the photocatalytic reactor or on the carrier to ensure that the lighting conditions in the photocatalytic reactor meet the requirements of the photocatalytic reaction. An ultraviolet light source is usually required in the photocatalytic reactor.

[0037] Specifically, the amount of ozone added to S2 entering the photocatalytic reactor needs to be controlled to ensure that it fully reacts with the ammonia nitrogen in the wastewater.

[0038] Specifically, during the reaction of the wastewater in S2 with ozone and photocatalyst, the photocatalyst generates electron-hole pairs under the irradiation of ultraviolet light, and then generates free radicals with strong oxidizing properties. These free radicals react with ammonia nitrogen in the wastewater and oxidize it into harmless nitrogen gas or other nitrogen oxides.

[0039] Specifically, we can simplify it into a general reaction formula:

[0040] 2NH3+3OH→N2+3H2O

[0041] It should be noted that this reaction formula is simplified and does not include all possible intermediate steps and products. In fact, the oxidation process of ammonia nitrogen may involve the generation and conversion of intermediate products such as nitrite and nitrate.

[0042] In addition, ozone O3 itself has strong oxidizing properties, and it can independently react with ammonia nitrogen or other intermediates in wastewater. Therefore, in the photocatalytic reactor, ozone and photocatalyst work synergistically, and they jointly promote the oxidation process of ammonia nitrogen.

[0043] Specifically, during the reaction of the wastewater in S2 with ozone and photocatalyst, the temperature, pressure and light intensity conditions of the photocatalytic reactor need to be controlled to ensure efficient reaction; the amount of ozone added and the reaction time are adjusted according to the properties of the wastewater and the treatment objectives.

[0044] Specifically, the subsequent treatment in S3 includes adjusting the pH value and removing residual ozone, and the subsequent treatment ensures that the effluent quality meets the discharge standards.

[0045] In this embodiment, the water quality monitoring in S5 includes ammonia nitrogen concentration, chemical oxygen demand, and pH value indicators.

[0046] The beneficial effects of the present invention are:

[0047] The method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation can effectively accelerate the degradation efficiency of ammonia nitrogen and more effectively remove the ammonia nitrogen components in the wastewater by adopting the above-mentioned wastewater treatment method to treat ammonia nitrogen wastewater; during the photocatalytic reaction, pollutants are decomposed into harmless substances and no secondary pollution problem will be generated; during the ozone oxidation process, ozone can be quickly decomposed to reduce the impact on subsequent treatment facilities, and at the same time, the photocatalytic reaction utilizes light energy, which has the advantages of energy saving and environmental protection, and achieves the advantages of efficient degradation, no secondary pollution, energy saving and environmental protection, and solves the problem that traditional wastewater treatment methods have certain limitations in treatment effect, cost, ease of operation and other aspects.

[0048] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation, characterized in that: The following steps are involved: S1. Preliminary preparation for wastewater treatment: perform necessary pretreatment on the original ammonia nitrogen wastewater; prepare the treatment equipment required for wastewater treatment; S2. Photocatalytic ozone oxidation coupling treatment: a photocatalyst is arranged in a photocatalytic reactor; ozone gas is generated by an ozone generator and introduced into the photocatalytic reactor through a pipeline; the pretreated ammonia nitrogen wastewater is then introduced into the photocatalytic reactor through a pipeline, and in the photocatalytic reactor, the wastewater is fully contacted with ozone and photocatalyst, and photocatalytic oxidation and ozone oxidation reactions occur; S3. Wastewater treatment: After the reaction is completed, the treated wastewater is discharged from the photocatalytic reactor, and necessary subsequent treatment is required for the wastewater during discharge; S4. Regeneration and recycling of catalysts: After long-term use, the photocatalyst will be deactivated due to the adsorption of pollutants. At this time, the catalyst needs to be regenerated to restore its activity; for catalysts that cannot be regenerated, they should be properly recycled and treated to avoid secondary pollution to the environment; S5. Monitoring of wastewater effluent quality: Regularly monitor the effluent quality and adjust the treatment process and parameters in a timely manner based on the monitoring results to ensure that the effluent quality is stable and meets the standards.

2. The method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation according to claim 1 is characterized in that: The pretreatment in S1 includes adjusting the pH value and removing suspended matter, and the pretreatment ensures the smooth progress of the subsequent treatment process.

3. The method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation according to claim 1 is characterized in that: The treatment equipment in S1 includes a photocatalytic reactor, an ozone generator, pipelines, valves and a control system.

4. The method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation according to claim 3 is characterized in that: The photocatalytic reactor needs to have good sealing properties and lighting conditions; the ozone generator is used to generate ozone gas; the pipeline, valve and control system are used to achieve continuous flow of wastewater and uniform distribution of ozone.

5. The method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation according to claim 1, characterized in that: The catalyst in S2 is titanium dioxide, and the catalyst should be evenly coated on the inner wall of the photocatalytic reactor or on the carrier to ensure that the lighting conditions in the photocatalytic reactor meet the requirements of the photocatalytic reaction. An ultraviolet light source is usually required in the photocatalytic reactor.

6. The method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation according to claim 1, characterized in that: The amount of ozone added to the photocatalytic reactor in S2 needs to be controlled to ensure that it fully reacts with the ammonia nitrogen in the wastewater.

7. The method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation according to claim 1, characterized in that: During the reaction of the wastewater in S2 with ozone and photocatalyst, the photocatalyst generates electron-hole pairs under the irradiation of ultraviolet light, and then generates free radicals with strong oxidizing properties. These free radicals react with ammonia nitrogen in the wastewater and oxidize it into harmless nitrogen gas or other nitrogen oxides.

8. The method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation according to claim 1, characterized in that: During the reaction of the wastewater in S2 with ozone and photocatalyst, the temperature, pressure and light intensity of the photocatalytic reactor need to be controlled to ensure efficient reaction; the dosage of ozone and the reaction time are adjusted according to the properties of the wastewater and the treatment objectives.

9. The method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation according to claim 1, characterized in that: The subsequent treatment in S3 includes adjusting the pH value and removing residual ozone, and the subsequent treatment ensures that the effluent quality meets the discharge standard.

10. The method for treating ammonia nitrogen wastewater based on coupling of photocatalysis and ozone oxidation according to claim 1, characterized in that: The water quality monitoring in S5 includes indicators of ammonia nitrogen concentration, chemical oxygen demand, and pH value.

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