Organic amine directional nitrification energy-saving process and device based on UV-LED and VUV cooperation

Abstract

The invention discloses an organic amine directional nitrification energy-saving process and device based on UV-LED and VUV cooperation, and belongs to the technical field of organic amine directional nitrification. The method comprises the following steps: introducing organic amine-containing wastewater into a first reaction zone, and adding H2O2 to carry out photocatalytic oxidation under the irradiation of a UV-LED light source with the wavelength of 265-280 nm, so that C-N bonds in organic amine molecules are broken and released; effluent is introduced into the second reaction zone, the concentration is monitored in real time through an online sensor, and a 185 nm VUV light source in the second reaction zone is automatically started and stopped. The energy-saving process and device are low in energy consumption, high in nitrogen conversion efficiency, free of secondary pollution, good in process applicability and compatibility, stable in system operation, high in adaptability and capable of being connected with a subsequent denitrification unit and providing a stable source for the subsequent denitrification unit to achieve more efficient removal of total nitrogen.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic amine directional nitration, in particular to an energy-saving process and device for organic amine directional nitration based on UV-LED and VUV cooperation. BACKGROUND

[0002] The organic amine industrial wastewater (such as printing and dyeing, pharmaceutical and other industrial wastewater) generally has the characteristics of high toxicity, difficult biodegradation, high ammonia nitrogen and low carbon-nitrogen ratio (C / N ≤ 3), and the nitrogen element in it mainly exists in the form of organic nitrogen. When using the traditional biological treatment process, it needs to go through a long ammoniation process before nitration and denitrification, which leads to long processing flow, low efficiency, high operation energy consumption, and is difficult to meet the efficient environmental protection processing demand.

[0003] In recent years, UV-LED technology as a new type of ultraviolet light source has attracted attention due to its long service life, low energy consumption, and wavelength selection advantages. Among them, the ultraviolet light of 265-280 nm band has good photolysis efficiency for H2O2, which can generate ·OH free radicals for degradation of organic matter. However, when the UV-LED of this band acts alone, it is difficult to achieve efficient and directional conversion of nitrogen elements in organic amine to nitrate nitrogen.

[0004] In the existing organic amine nitration process, there is also a technical route of using 185 nm VUV light source for direct oxidation, but it has obvious defects: on the one hand, the 185 nm VUV light source has high power density and high energy consumption, and needs to be continuously operated, resulting in high cost of electricity consumption per unit volume of wastewater; on the other hand, the breaking efficiency of C-N bond in organic amine molecules is limited, and part of the macromolecular organic amine cannot be completely degraded into the subsequent oxidation link, resulting in reduced conversion efficiency, and easy generation of intermediate by-products such as (NO2)-N and (NO3)-N, affecting the subsequent denitrification effect.

[0005] In addition, although some existing technologies (such as CN114212945A, CN112939234A, etc.) mention the use of UV-LED combined with VUV, they do not provide effective solutions to the core problem of "how to realize system energy saving through the functional division of the two light sources", and lack specific energy consumption comparison data support. Therefore, the existing technology still cannot significantly reduce the system operation energy consumption while ensuring efficient conversion and environmental standard.

[0006] Therefore, it is necessary to provide an energy-saving process and device for organic amine directional nitration based on UV-LED and VUV cooperation to solve the problems raised in the background art. SUMMARY

[0007] To achieve the above purpose, the present application provides the following technical solutions: ​

[0008] An energy-saving process for the directional nitration of organic amines based on the synergy of UV-LED and VUV, characterized by the following steps:

[0009] (a) Passing wastewater containing organic amines into a first reaction zone, under the irradiation of a UV-LED light source with a wavelength of 265-280 nm, and adding H2O2 for photocatalytic oxidation, so that the C-N bond in the organic amine molecule is broken and ;

[0010] (b) Passing the effluent from step (a) into a second reaction zone, and monitoring the concentration in real time by an online sensor arranged in the connecting pipeline between the two reaction zones;

[0011] (c) When the monitored concentration is not less than a set threshold value, automatically starting the 185 nm VUV light source in the second reaction zone to oxidize to ; and when the monitored concentration is less than the set threshold value, turning off the 185 nm VUV light source.

[0012] Preferably, the organic amines are selected from one or more of aniline, N,N-dimethylaniline, azo dyes, melamine, pyridine, or quinoline.

[0013] Preferably, in step (a), the power density of the UV-LED light source is 30-80 W / m 3 , the hydraulic retention time is 10-30 minutes, the pH is 9, and the mass ratio of H2O2 to influent COD is (2-5):1.

[0014] Preferably, in step (c), the set threshold value is 10 mg / L; the 185 nm VUV light source is a low-pressure mercury lamp that simultaneously emits wavelengths of 185 nm and 254 nm, and the power density is 100-150 W / m 3 .

[0015] Preferably, in step (a), the influent COD value is monitored in real time by a COD online monitoring device at the influent end of the system, and the dosage of H2O2 is dynamically adjusted accordingly.

[0016] Preferably, the wastewater containing organic amines is industrial wastewater with a C / N ratio of ≤3, including dyeing wastewater, pharmaceutical wastewater, pesticide wastewater, or landfill leachate.

[0017] Preferably, in step (c), the start and stop of the 185 nm VUV light source are performed by a controller, which receives the ​The signal from the online sensor is used, and a hysteresis control range of ±2 mg / L is set to prevent frequent start-stop of the equipment.

[0018] An energy-saving device for the directional nitration of organic amines to achieve the above process, characterized in that it comprises:

[0019] The first reaction zone contains a UV-LED light source array in the 265–280 nm band, an H2O2 dosing port, and a mixing device.

[0020] The second reaction zone contains a 185 nm VUV light source.

[0021] An online sensor is installed on the connecting pipe between the water outlet of the first reaction zone and the water inlet of the second reaction zone;

[0022] Controller, and the The online sensor is electrically connected to the 185 nm VUV light source and is used to control the start and stop of the 185 nm VUV light source according to the sensor signal.

[0023] Preferably, the UV-LED light source array is an adjustable light intensity module, and its driving power supply supports PWM dimming with a dimming range of 20%–100%.

[0024] Preferably, the system also includes an online COD / TN monitoring device installed at the system inlet. The controller is electrically connected to the online COD / TN monitoring device and the metering pump at the H2O2 dosing port, and is used to adjust the H2O2 dosage according to the COD value of the inlet water.

[0025] Preferably, the controller is a PLC controller.

[0026] Preferably, the outlet of the second reactor zone is connected to anoxic denitrification unit for utilizing the water generated by this system. It removes total nitrogen by denitrifying with residual organic matter in the raw water or by adding an external carbon source.

[0027] Compared with existing technologies, this invention provides an energy-saving process and apparatus for the directional nitration of organic amines based on the synergy of UV-LED and VUV, which has the following beneficial effects:

[0028] (1) Significantly reduced energy consumption: Through the synergistic oxidation of different ultraviolet light sources and intelligent start-stop control, the overall power consumption of the system can be reduced by more than 30% compared with the use of 185nm VUV lamp alone, and the energy-saving effect is obvious;

[0029] (2) High nitrogen conversion efficiency: It can achieve the directional and efficient conversion of organic nitrogen to nitrate nitrogen. Yield ≥ 90% (based on total nitrogen);

[0030] (3) No secondary pollution: It reduces the intensity of use of high environmental risk light sources such as traditional mercury lamps, thus reducing the potential risk of secondary pollution;

[0031] (4) Good process applicability and compatibility: It is especially suitable for the treatment of highly stable organic amine wastewater with a C / N ratio ≤3. The system operates stably and has strong adaptability. It can be connected to the subsequent denitrification unit and provide it with stable water supply. The source achieves more efficient removal of total nitrogen. Attached Figure Description

[0032] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] It should be noted that terms such as "upper", "lower", "left", "right", and "middle" used in this specification are only for clarity of description and are not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of this application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0036] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0037] As used herein, the term “about” is used to provide for the flexibility and imprecision associated with a given term, measure, or value. Those skilled in the art can readily determine the degree of flexibility for a particular variable.

[0038] As used herein, the term “at least one of…” is intended to be synonymous with “one or more of…”. For example, “at least one of A, B, and C” explicitly includes only A, only B, only C, and combinations thereof.

[0039] Concentration, amount, and other numerical data may be presented in range format herein. It should be understood that such range format is used solely for convenience and brevity and should be flexibly interpreted to include not only the values ​​explicitly stated as the limits of the range, but also all individual values ​​or subranges encompassed within the range, as if each value and subrange were explicitly stated. For example, a range of values ​​from about 1 to about 4.5 should be interpreted to include not only the explicitly stated limits of 1 to 4.5, but also individual numbers (such as 2, 3, 4) and subranges (such as 1 to 3, 2 to 4, etc.). The same principle applies to ranges that describe only a single value, such as "less than about 4.5," which should be interpreted to include all the values ​​and ranges described above. Furthermore, this interpretation should apply regardless of the breadth of the range or characteristic described.

[0040] Example 1

[0041] Combination Figure 1 This embodiment provides an energy-saving process for the directional nitration of organic amines based on the synergy of UV-LED and VUV, specifically including:

[0042] The raw water for treatment was taken from a chemical plant, and its quality was: COD=206 mg / L, TN=85 mg / L (of which organic nitrogen accounted for more than 90%), C / N=2.4.

[0043] Step 1: After adjusting the pH of the wastewater to 9, it enters the first reaction zone, using a main wavelength of 280 nm and a power density of 30 W / m³. 3 The mixture was irradiated with a UV-LED light source, and H2O2 was added at a dosage of 800 mg / L. The hydraulic retention time was set to 20 minutes. After this stage of treatment, the aniline degradation rate was 86%. The concentration increased to 65 mg / L.

[0044] Step 2: The effluent enters the second reaction zone, which is equipped with a 185 nm VUV mercury lamp with a power density of 120 W / m³. 3 .pass Online sensor monitoring indicates that when the concentration is not lower than 10 mg / L, the PLC controller automatically starts the VUV mercury lamp; after 20 minutes of irradiation, When the concentration drops to 9 mg / L, the PLC controller automatically shuts off the VUV mercury lamp.

[0045] After the above process, the effluent The concentration was 77 mg / L, and the nitrate nitrogen yield (based on total nitrogen) reached 90.6%. The total power consumption per unit volume of water treated in this embodiment was 4.8 kWh / m³. 3 .

[0046] Comparative Example 1A

[0047] The raw water for treatment was taken from a chemical plant, and its quality was: COD=206 mg / L, TN=85 mg / L (of which organic nitrogen accounted for more than 90%), C / N=2.4.

[0048] After adjusting the pH of the wastewater to 9, it enters the first reaction zone, using a dominant wavelength of 280 nm and a power density of 30 W / m³. 3 The solution was irradiated with a UV-LED light source, and H2O2 was added at a dosage of 800 mg / L. The hydraulic retention time was set to 20 minutes.

[0049] After treatment, the aniline degradation rate was 86%. When the concentration increased to 65 mg / L, the power consumption was 0.96 kWh / m³. 3 ,but The yield was only 4%, which was insufficient to complete the nitrification process.

[0050] Comparative Example 1B

[0051] The raw water for treatment was taken from a chemical plant, and its quality was: COD=206 mg / L, TN=85 mg / L (of which organic nitrogen accounted for more than 90%), C / N=2.4.

[0052] After adjusting the pH of the wastewater to 9, a 185 nm VUV mercury lamp with a power density of 120 W / m³ was used. 3 The wastewater was treated, and H2O2 was added at a dosage of 800 mg / L, followed by irradiation for 20 minutes.

[0053] After treatment, the power consumption is 3.84 kWh / m³. 3 , The yield was 69%.

[0054] Comparative Example 1C

[0055] The raw water for treatment was taken from a chemical plant, and its quality was: COD=206 mg / L, TN=85 mg / L (of which organic nitrogen accounted for more than 90%), C / N=2.4.

[0056] After adjusting the pH of the wastewater to 9, a 185 nm VUV mercury lamp with a power density of 120 W / m³ was used. 3 The wastewater was treated by adding H2O2 at a dosage of 800 mg / L. Online sensor monitoring, when When the concentration is <10 mg / L, stop irradiation for 40 minutes.

[0057] After treatment, the power consumption is 7.68 kWh / m³. Yield: 90.3%.

[0058] Compared with the comparative example, Example 3 shows that the synergistic effect of UV-LED and VUV is obvious, and the power consumption can be saved by 37.5% compared with the use of 185 nm VUV alone.

[0059] The specific test results are shown in Table 1:

[0060] Table 1

[0061]

[0062] Example 2

[0063] Combination Figure 1 This embodiment provides an energy-saving process for the directional nitration of organic amines based on the synergy of UV-LED and VUV, specifically including:

[0064] The raw water for treatment was taken from pesticide wastewater from a chemical plant. The water quality was as follows: COD=420mg / L, TN=140 mg / L (of which organic nitrogen accounted for more than 90%), C / N = 3, and the main pollutants were pyridine and melamine derivatives.

[0065] Step 1: After adjusting the pH of the wastewater to 9, it enters the first reaction zone, using a main wavelength of 275 nm and a power density of 50 W / m³. 3 The solution was irradiated with a UV-LED light source, and H2O2 was added at a dosage of 1260 mg / L, with a hydraulic retention time set to 25 minutes. After this stage of treatment, the organic nitrogen removal rate reached 89%. The concentration increased to 125 mg / L.

[0066] Step 2: The effluent enters the second reaction zone, which is equipped with a 185 nm VUV mercury lamp with a power density of 120 W / m³. 3 .pass Online sensor monitoring indicates that when the concentration reaches at least 10 mg / L, the PLC controller automatically activates the VUV mercury lamp. After 40 minutes of irradiation, When the concentration drops to 8 mg / L, the PLC controller automatically shuts off the VUV mercury lamp.

[0067] After the above process, the effluent The concentration was 131 mg / L, and the nitrate nitrogen yield (based on total nitrogen) reached 93.6%. The total power consumption per unit volume of water treated in this embodiment was 9.6 kWh / m³. 3 .

[0068] Comparative Example 2A

[0069] The raw water for treatment was taken from pesticide wastewater from a chemical plant. The water quality was as follows: COD=420mg / L, TN=140 mg / L (of which organic nitrogen accounted for more than 90%), C / N = 3, and the main pollutants were pyridine and melamine derivatives.

[0070] After adjusting the pH of the wastewater to 9, it enters the first reaction zone, using a dominant wavelength of 275 nm and a power density of 50 W / m³. 3 The solution was irradiated with a UV-LED light source, and H2O2 was added at a dosage of 1260 mg / L. The hydraulic retention time was set to 25 minutes.

[0071] After treatment, the organic nitrogen removal rate of the effluent reached 89%. When the concentration increased to 125 mg / L, the power consumption was 2.0 kWh / m³. 3 , The yield was only 4.8%, which was insufficient to complete the nitrification process.

[0072] Comparative Example 2B

[0073] The raw water for treatment was taken from pesticide wastewater from a chemical plant. The water quality was as follows: COD=420mg / L, TN=140 mg / L (of which organic nitrogen accounted for more than 90%), C / N = 3, and the main pollutants were pyridine and melamine derivatives.

[0074] After adjusting the pH of the wastewater to 9, a 185 nm VUV mercury lamp with a power density of 120 W / m³ was used. 3 The wastewater was treated, and H2O2 was added at a dosage of 1260 mg / L, followed by irradiation for 40 minutes.

[0075] After treatment, the power consumption is 7.6 kWh / m³. 3 , The yield was 77.2%.

[0076] Comparative Example 2C

[0077] The raw water for treatment was taken from pesticide wastewater from a chemical plant. The water quality was as follows: COD=420mg / L, TN=140 mg / L (of which organic nitrogen accounted for more than 90%), C / N = 3, and the main pollutants were pyridine and melamine derivatives.

[0078] After adjusting the pH of the wastewater to 9, a 185 nm VUV mercury lamp with a power density of 120 W / m³ was used. 3 The wastewater was treated by adding H2O2 at a dosage of 1260 mg / L. Online sensor monitoring, when When the concentration is <10mg / L, stop irradiation after 75 minutes.

[0079] After treatment, the power consumption is 14.4 kWh / m³. 3 , Yield: 93.3%.

[0080] Compared with the comparative example, Example 2 shows that the synergistic effect of UV-LED and VUV is obvious, and the power consumption can be saved by 33.3% compared with the use of 185 nm VUV alone.

[0081] The specific test results are shown in Table 2:

[0082] Table 2

[0083]

[0084] Example 3

[0085] Combination Figure 1 This embodiment provides an energy-saving process for the directional nitration of organic amines based on the synergy of UV-LED and VUV, specifically including:

[0086] The raw water for treatment was taken from azo dye wastewater from a chemical plant. The water quality was as follows: COD=134mg / L, TN=120mg / L (of which organic nitrogen accounted for more than 90%), and C / N = 0.9.

[0087] Step 1: After adjusting the pH of the wastewater to 9, it enters the first reaction zone and is irradiated with a UV-LED light source with a main wavelength of 275 nm and a power density of 50 W / m³. H₂O₂ is added at a dosage of 670 mg / L, and the hydraulic retention time is set to 30 minutes. After this stage of treatment, the azo degradation rate is 85%. The concentration increased to 102 mg / L.

[0088] Step 2: The effluent enters the second reaction zone, which is equipped with a 185 nm VUV mercury lamp with a power density of 150 W / m³. 3 .pass Online sensor monitoring indicates that when the concentration reaches at least 10 mg / L, the PLC controller automatically activates the VUV mercury lamp. After 28 minutes of irradiation, When the concentration drops to 8 mg / L, the PLC controller automatically shuts off the VUV mercury lamp.

[0089] After the above process, the effluent The concentration was 111 mg / L, and the nitrate nitrogen yield (based on total nitrogen) reached 92.5%. The total power consumption per unit volume of water treated in this embodiment was 9.12 kWh / m³. 3 .

[0090] Comparative Example 3A

[0091] The raw water for treatment was taken from azo dye wastewater from a chemical plant. The water quality was as follows: COD=134mg / L, TN=120mg / L (of which organic nitrogen accounted for more than 90%), and C / N = 0.9.

[0092] After adjusting the pH of the wastewater to 9, it enters the first reaction zone, using a dominant wavelength of 275 nm and a power density of 50 W / m³. 3 The solution was irradiated with a UV-LED light source, and H2O2 was added at a dosage of 670 mg / L. The hydraulic retention time was set to 30 minutes.

[0093] After treatment, the organic nitrogen removal rate of the effluent reached 85%. When the concentration increased to 102 mg / L, the power consumption was 2.4 kWh / m³. 3 , The yield was only 3.7%, which was insufficient to complete the nitrification process.

[0094] Comparative Example 3B

[0095] The raw water for treatment was taken from azo dye wastewater from a chemical plant. The water quality was as follows: COD=134mg / L, TN=120mg / L (of which organic nitrogen accounted for more than 90%), and C / N = 0.9.

[0096] After adjusting the pH of the wastewater to 9, a 185 nm VUV mercury lamp with a power density of 150 W / m³ was used. 3 The wastewater was treated, and H2O2 was added at a dosage of 670 mg / L, followed by irradiation for 28 minutes.

[0097] After treatment, the power consumption is 6.72 kWh / m³. 3 , The yield was 71.6%.

[0098] Comparative Example 3C

[0099] The raw water for treatment was taken from azo dye wastewater from a chemical plant. The water quality was as follows: COD=134mg / L, TN=120mg / L (of which organic nitrogen accounted for more than 90%), and C / N = 0.9.

[0100] After adjusting the pH of the wastewater to 9, a 185 nm VUV mercury lamp with a power density of 150 W / m³ was used. 3 The wastewater was treated by adding H2O2 at a dosage of 670 mg / L. Online sensor monitoring, when When the concentration is <10 mg / L, irradiation is stopped after 64 minutes.

[0101] After treatment, the power consumption is 15.36 kWh / m³. 3 , Yield: 92.5%.

[0102] Compared with the comparative example, Example 3 shows that the synergistic effect of UV-LED and VUV is obvious, and the power consumption can be saved by 40.6% compared with the use of 185 nm VUV alone.

[0103] The specific test results are shown in Table 3:

[0104] Table 3

[0105]

[0106] Example 4

[0107] Combination Figure 1 This embodiment provides an energy-saving process for the directional nitration of organic amines based on the synergy of UV-LED and VUV, specifically including:

[0108] The raw water for treatment was taken from a chemical plant with low-concentration pharmaceutical wastewater. The water quality was: COD=150mg / L, TN=60mg / L (of which organic nitrogen accounted for more than 90%), and C / N = 2.5.

[0109] Step 1: After adjusting the pH of the wastewater to 9, it enters the first reaction zone, using a main wavelength of 265 nm and a power density of 80 W / m³. 3 The azo dyes were irradiated with a UV-LED light source, and H2O2 was added at a dosage of 300 mg / L. The hydraulic retention time was set to 10 minutes. After this stage of treatment, the azo degradation rate was 87%. The concentration increased to 52 mg / L.

[0110] Step 2: The effluent enters the second reaction zone, which is equipped with a 185 nm VUV mercury lamp with a power density of 100 W / m³. 3 .pass Online sensor monitoring indicates that when the concentration reaches at least 10 mg / L, the PLC controller automatically activates the VUV mercury lamp. After 20 minutes of irradiation, When the concentration drops to 4 mg / L, the PLC controller automatically shuts off the VUV mercury lamp.

[0111] After the above process, the effluent The concentration was 55 mg / L, and the nitrate nitrogen yield (based on total nitrogen) reached 91.7%. The total power consumption per unit volume of water treated in this embodiment was 4.48 kWh / m³. 3 .

[0112] Comparative Example 4A

[0113] The raw water for treatment was taken from a chemical plant with low-concentration pharmaceutical wastewater. The water quality was: COD=150mg / L, TN=60mg / L (of which organic nitrogen accounted for more than 90%), and C / N = 2.5.

[0114] After adjusting the pH of the wastewater to 9, it enters the first reaction zone, using a dominant wavelength of 265 nm and a power density of 80 W / m³. 3 The solution was irradiated with a UV-LED light source, and H2O2 was added at a dosage of 300 mg / L. The hydraulic retention time was set to 10 minutes.

[0115] After treatment, the organic nitrogen removal rate of the effluent reached 87%. When the concentration increased to 52 mg / L, the power consumption was 1.28 kWh / m³. 3 , The yield was only 4.2%, which was insufficient to complete the nitrification process.

[0116] Comparative Example 4B

[0117] The raw water for treatment was taken from a chemical plant with low-concentration pharmaceutical wastewater. The water quality was: COD=150mg / L, TN=60mg / L (of which organic nitrogen accounted for more than 90%), and C / N = 2.5.

[0118] After adjusting the pH of the wastewater to 9, a 185 nm VUV mercury lamp with a power density of 100 W / m³ was used. 3 The wastewater was treated, and H2O2 was added at a dosage of 300 mg / L, followed by irradiation for 20 minutes.

[0119] After treatment, the power consumption is 3.20 kWh / m³. 3 , The yield was 73.1%.

[0120] Comparative Example 4C

[0121] The raw water for treatment was taken from a chemical plant with low-concentration pharmaceutical wastewater. The water quality was: COD=150mg / L, TN=60mg / L (of which organic nitrogen accounted for more than 90%), and C / N = 2.5.

[0122] After adjusting the pH of the wastewater to 9, a 185 nm VUV mercury lamp with a power density of 100 W / m³ was used. 3 The wastewater was treated by adding H2O2 at a dosage of 300 mg / L. Online sensor monitoring, when When the concentration is <10 mg / L, stop irradiation after 45 minutes.

[0123] After treatment, the power consumption is 7.20 kWh / m³. 3 , Yield: 90.8%.

[0124] Compared with the comparative example, Example 4 shows that the synergistic effect of UV-LED and VUV is obvious, and the power consumption can be saved by 37.8% compared with the use of 185 nm VUV alone.

[0125] The specific test results are shown in Table 4:

[0126] Table 4

[0127]

[0128] The data from the above embodiments demonstrate that the energy-saving process for directional nitrification of organic amines based on the synergy of UV-LED and VUV provided by the present invention, for organic amine wastewater from different sources and with different C / N ratios, while ensuring that the nitrate nitrogen yield is higher than 90%, achieves a significant energy saving effect of 33.3% to 40.6% by efficiently mineralizing organic nitrogen with UV-LED at the front end and intelligently starting and stopping VUV at the back end, compared with a single VUV process that requires long-term operation to achieve the same nitrification target (Comparative Example C).

[0129] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0130] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. An energy-saving process for the directional nitration of organic amines based on the synergy of UV-LED and VUV, characterized in that, Includes the following steps: (a) Wastewater containing organic amines is introduced into the first reaction zone. Under UV-LED light source with a wavelength of 265–280 nm, H2O2 is added for photocatalytic oxidation, causing the CN bonds in the organic amine molecules to break and release the organic amines. ; (b) The effluent from step (a) is introduced into the second reaction zone and then passed through the connecting pipeline between the two reaction zones. Real-time monitoring of online sensors concentration; (c) When detected When the concentration is not lower than the set threshold, the 185 nm VUV light source in the second reaction zone is automatically activated. Oxidized to When detected When the concentration is below the set threshold, the 185 nm VUV light source is turned off.

2. The energy-saving process for directional nitration of organic amines based on the synergy of UV-LED and VUV as described in claim 1, characterized in that, The organic amine is selected from one or more of aniline, N,N-dimethylaniline, azo dyes, melamine, pyridine, or quinoline.

3. The energy-saving process for directional nitration of organic amines based on the synergy of UV-LED and VUV as described in claim 1, characterized in that, In step (a), the power density of the UV-LED light source is 30–80 W / m². 3 The hydraulic retention time is 10–30 minutes, the pH is 9, and the mass ratio of H2O2 to influent COD is (2–5):

1.

4. In the energy-saving process for directional nitration of organic amines based on the synergy of UV-LED and VUV as described in claim 1, in step (c), the set threshold is 10 mg / L; the 185 nm VUV light source is a low-pressure mercury lamp that simultaneously emits wavelengths of 185 nm and 254 nm, with a power density of 100–150 W / m². 3 .

5. The energy-saving process for directional nitration of organic amines based on the synergy of UV-LED and VUV as described in claim 3, characterized in that, In step (a), the COD value of the influent is monitored in real time by the COD online monitoring device at the system inlet, and the amount of H2O2 added is dynamically adjusted accordingly.

6. The energy-saving process for directional nitration of organic amines based on the synergy of UV-LED and VUV as described in claim 1, characterized in that, The wastewater containing organic amines is industrial wastewater with a C / N ratio ≤ 3, including dyeing and printing wastewater, pharmaceutical wastewater, pesticide wastewater, or landfill leachate.

7. The energy-saving process for directional nitration of organic amines based on the synergy of UV-LED and VUV as described in claim 1, characterized in that, In step (c), the start-up and shutdown of the 185 nm VUV light source are executed by the controller, which receives the... The signal from the online sensor is used, and a hysteresis control range of ±2 mg / L is set to prevent frequent start-stop of the equipment.

8. An energy-saving device for implementing the directional nitration of organic amines according to any one of claims 1-7, characterized in that, include: The first reaction zone contains a UV-LED light source array in the 265–280 nm band, an H2O2 dosing port, and a mixing device. The second reaction zone contains a 185 nm VUV light source. An online sensor is installed on the connecting pipe between the water outlet of the first reaction zone and the water inlet of the second reaction zone; Controller, and the The online sensor is electrically connected to the 185 nm VUV light source and is used to control the start and stop of the 185 nm VUV light source according to the sensor signal.

9. The energy-saving device for directional nitration of organic amines according to claim 8, characterized in that, The UV-LED light source array is an adjustable light intensity module, and its driving power supply supports PWM dimming with a dimming range of 20%–100%.

10. The energy-saving device for directional nitration of organic amines according to claim 8, characterized in that, It also includes an online COD / TN monitoring device installed at the system inlet. The controller is electrically connected to the online COD / TN monitoring device and the metering pump at the H2O2 dosing port, and is used to adjust the H2O2 dosage according to the COD value of the inlet water.

11. The energy-saving device for directional nitration of organic amines according to claim 8, characterized in that, The controller is a PLC controller.

12. The energy-saving device for directional nitration of organic amines according to claim 8, characterized in that, The outlet of the second reactor zone is connected to the anoxic denitrification unit for utilizing the water generated by this system. It removes total nitrogen by denitrifying with residual organic matter in the raw water or by adding an external carbon source.

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