Method for efficiently degrading common dyes in wastewater by using UV222 in combination with sodium perborate

Abstract

The invention discloses a method for efficiently degrading common dyes in wastewater by using UV222 in combination with sodium perborate, and relates to the technical field of water treatment. UV222 (wavelength of 222nm) released by a plasma generator is combined with sodium perborate to form a synergistic oxidation system, high-activity free radicals are generated through photochemical activation, and efficient degradation of common dye pollutants in a water body is realized. A UV222 light source with a specific wavelength is adopted, so that the activation efficiency and the free radical yield of sodium perborate can be remarkably improved. Experiments show that the 30 min degradation rate of the method to methylene blue (MB) can reach 95% or above, and the method is suitable for various common dyes such as rhodamine B, malachite green, methyl orange and methyl violet. Compared with a conventional dye treatment technology, the method has the advantages of being higher in efficiency, lower in cost, simpler and more convenient to operate and remarkable in application value.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to a method of using a plasma generator to release UV radiation. 222 A method for combining sodium perborate with common dyes in wastewater. Background Technology

[0002] Synthetic dyes are widely used in industries such as textiles, printing and dyeing, and papermaking. With the acceleration of industrialization and urbanization, large amounts of dye wastewater, after direct discharge or partial treatment, enter natural water bodies, causing serious water pollution. As a typical emerging organic pollutant, synthetic dye wastewater typically exhibits characteristics such as high color intensity, high chemical oxygen demand, and poor biodegradability. This not only poses a threat to aquatic life and aquaculture but also directly endangers human health due to its own toxicity and the potential carcinogens produced during degradation.

[0003] Existing wastewater treatment technologies, such as physical, chemical, and biological methods, suffer from low degradation efficiency, high energy consumption, and a tendency to generate secondary pollution or fail to achieve complete mineralization. While the Fenton oxidation process is widely used in advanced oxidation technologies, it has drawbacks such as a narrow pH range and the formation of iron sludge leading to secondary pollution. This invention also belongs to advanced oxidation technologies, utilizing a combined photochemical process and UV... 222 The synergistic effect of ultraviolet light and sodium perborate, with the help of the strong oxidizing properties of active free radicals, can effectively overcome the above-mentioned technical shortcomings by degrading common dyes. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing water treatment technologies by providing a method using UV... 222 A method combining sodium perborate for the efficient degradation of common dyes was proposed to achieve the technical goals of simple operation, low energy consumption, low cost, and high removal efficiency.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A far-ultraviolet (UV) light emitted using a plasma generator 222 The method for efficiently degrading common dyes using sodium perborate comprises the following steps:

[0007] 1) Add sodium perborate at a concentration not exceeding 2.0 mM to the water containing the dye to be degraded;

[0008] 2) Insert the electrodes of the plasma generator into the solution obtained in step 1 to generate UV. 222 (Wavelength 222nm) Irradiation of water body;

[0009] 3) Control reaction conditions: pH 3.0~9.0, reaction time ≤40min, to achieve efficient degradation of dye.

[0010] In step 1), the dye to be degraded is selected from one of methylene blue, rhodamine B, malachite green, methyl orange, and methyl violet. The concentration of sodium perborate is 0.2–1.4 mM, preferably 0.6–1.4 mM; the concentration of the dye to be degraded is 5–20 mg / L.

[0011] In step 2), the plasma generator can be a CTP-2000K plasma generator; the discharge type of the plasma generator is dielectric barrier discharge, and an AC power supply is used; the electrode structure includes a high-voltage electrode and a ground electrode, and the electrode materials can be copper and iron, with a spectral purity greater than 95%. The power supply of the plasma generator can be 70W, and the lamp power can be 20W.

[0012] The electrode of the plasma generator is inserted into the solution obtained in step 1. The depth of immersion of the electrode of the plasma generator in the water can be 2 cm. During operation, the voltage is adjusted to 60V and the current can be adjusted to 0.60A.

[0013] In step 3), the pH of the water is 3.0 to 9.0, the reaction time is 30 min, the reaction temperature can be 25±2℃, and the stirring rate during the reaction can be 700 rpm.

[0014] This invention has the following outstanding advantages and technical effects:

[0015] 1. This invention utilizes short-wave UV light emitted by a plasma generator. 222 By introducing a sodium perborate activation system, the photon energy of this wavelength of ultraviolet light is higher than that of conventional 254nm UV light, which can significantly improve the activation efficiency of sodium perborate. This generates more free radicals to remove colored dyes from the water, resulting in a significantly better degradation effect than using UV light alone. 222 Alternatively, sodium perborate can be used to degrade dyes.

[0016] 2. The method of this invention has high degradation efficiency for dyes; under specific conditions, the degradation rate of methylene blue can reach 95% within 30 minutes.

[0017] 3. The chemical reagents used in the experiments of this invention are readily available and inexpensive, and the operation is simple, the equipment is simple, and the energy consumption is low.

[0018] 4. This invention has high applicability and is easy to promote and apply. Attached Figure Description

[0019] Figure 1 For different systems (UV) 222 Sodium perborate alone, sodium perborate alone, UV 222 Comparison of the degradation effects of sodium perborate (in combination) on methylene blue.

[0020] Figure 2To study the effects of different sodium perborate concentrations on UV radiation 222 + Effect of sodium perborate combined system on the degradation of methylene blue.

[0021] Figure 3 pH to UV 222 + Effect of sodium perborate combined system on the degradation of methylene blue.

[0022] Figure 4 To differentiate the effects of different inorganic ions and natural organic matter on UV radiation 222 + Effect of sodium perborate combined system on the degradation of methylene blue.

[0023] Figure 5 UV 222 + Comparison of the degradation effects of different concentrations of methylene blue by the sodium perborate combined system.

[0024] Figure 6 UV 222 + The effect of the sodium perborate combined system on the combined degradation of five common dyes (methylene blue, rhodamine B, malachite green, methyl orange, and methyl violet). Detailed Implementation

[0025] To facilitate a better understanding of the present invention, a more comprehensive and specific description of the present invention will be provided below in conjunction with relevant accompanying drawings and embodiments.

[0026] Example 1

[0027] This embodiment uses the controlled variable method to set different UV values ​​under the same initial dye concentration. 222 The optimal degradation system was determined by comparing the degradation efficiency of methylene blue (MB) in the dye within 30 minutes using a sodium perborate solution system.

[0028] Prepare three 50 mL methylene blue solutions, each with a concentration of 10 mg / L. Adjust the pH of all water samples to 7.0 ± 0.1 using 0.1 mol / L HCl and 0.1 mol / L KOH to maintain a stable acid-base environment for the reaction. Variable settings: The systems are: individual UV... 222 Irradiation, 1.0 mmol / L sodium perborate alone, UV 222 Irradiation was combined with 1.0 mmol / L sodium perborate. The reaction vessel was a 250 ml jacketed beaker, with cooling water supplied by a pump at a speed of 50.0 rpm. Magnetic stirring was applied for 10 minutes until completely dissolved, at a stirring speed of 300 rpm to ensure uniform dispersion of the solute.

[0029] Reaction conditions: A CTP-2000K plasma generator was used (discharge type: dielectric barrier discharge; AC power supply; electrode structure: high-voltage electrode and ground electrode; materials: copper and iron; spectral purity greater than 95%; power supply: 70W; lamp power: 20W), ensuring UV protection. 222 Stable supply. Electrode immersion depth 2cm, voltage 60V, current 0.60A, reaction temperature 25±2℃, environmental variables controlled; stirring speed 700rpm to ensure uniform mixing of the reaction system. Two parallel experiments were set up for each concentration gradient, and the average value was calculated to reduce error and ensure data reliability. Detection method: Samples were taken at 0 min, 5 min, 10 min, 15 min, 20 min, 25 min, and 30 min of reaction, covering the entire reaction time. After filtration through a 0.22μm filter membrane, absorbance was measured at 663.6nm using a UV spectrophotometer, and quantification was performed using the characteristic absorption peak. The degradation rate at different time points was calculated, and the average value of the two parallel experiments was taken.

[0030] See results Figure 1 This invention verifies the removal effect of different systems on dye MB by using UV alone. 222 Sodium perborate alone, or UV radiation. 222 The combined system of sodium perborate and UV-treated water samples showed that only UV light... 222 Only a combined system with sodium perborate can rapidly degrade dye MB. After 30 minutes of reaction, the removal rate of dye MB reaches over 95%.

[0031] Example 2

[0032] This embodiment uses the controlled variable method to achieve the same UV... 222 Under different irradiation conditions and initial dye concentrations, different sodium perborate concentration gradients were set, and the degradation efficiency of methylene blue (MB) within 30 minutes was compared to determine the optimal concentration range.

[0033] Prepare four 50 mL methylene blue solutions, each with a concentration of 10 mg / L (consistent with Example 1 to ensure data comparability). Adjust the pH of all water samples to 7.0 ± 0.1 using 0.1 mol / L HCl and 0.1 mol / L KOH to maintain a stable acid-base environment for the reaction. Variable setting: Add sodium perborate to the four water samples to create a concentration gradient of 0.2 mmol / L, 0.6 mmol / L, 1.0 mmol / L, and 1.4 mmol / L, respectively. Stir magnetically for 10 min until completely dissolved at a stirring speed of 300 rpm to ensure uniform dispersion of the sodium perborate.

[0034] Reaction conditions: The same CTP-2000K plasma generator as in Example 1 was used. The electrode immersion depth was 2 cm, the voltage was adjusted to 60V, the current to 0.60A, and the reaction temperature was 25±2℃. Environmental variables were controlled. The stirring rate was 700 rpm to ensure uniform mixing of the reaction system. Two parallel experiments were set up for each concentration gradient, and the average value was calculated to reduce errors and ensure data reliability. Detection method: Samples were taken at 0 min, 5 min, 10 min, 15 min, 20 min, 25 min, and 30 min of the reaction, covering the entire reaction period. After filtration through a 0.22 μm filter membrane, the absorbance was measured at 663.6 nm using a UV spectrophotometer, and quantification was performed using the characteristic absorption peak. The degradation rate at different time points was calculated, and the average value of the two parallel experiments was taken.

[0035] The results are as follows Figure 2 As shown, when the sodium perborate concentration is 0.6–1.4 mmol / L, the degradation effect is excellent within 30 min. If it is necessary to shorten the reaction time, the sodium perborate concentration can be further increased.

[0036] Example 3

[0037] This embodiment uses the controlled variable method to achieve the same UV... 222 Under different irradiation conditions and initial concentrations of dye and sodium perborate, different solution pH values ​​were set, and the degradation efficiency of methylene blue (MB) within the dye was compared over 30 minutes to determine the optimal pH range.

[0038] Prepare four 50 mL methylene blue solutions, each with a concentration of 10 mg / L. Add sodium perborate to the solutions to achieve a concentration of 1.0 mmol / L. Adjust the pH of the water samples to 3.0 ± 0.1, 5.0 ± 0.1, 7.0 ± 0.1, and 9.0 ± 0.1, respectively, by adding appropriate amounts of 0.1 mol / L HCl and 0.1 mol / L KOH. Stir magnetically for 10 min at a stirring speed of 300 rpm to ensure uniform solute dispersion.

[0039] Reaction conditions: The same CTP-2000K plasma generator as in Example 1 was used. The electrode immersion depth was 2 cm, the voltage was adjusted to 60V, the current to 0.60A, and the reaction temperature to 25±2℃. Environmental variables were controlled. The stirring rate was 700 rpm to ensure uniform mixing of the reaction system. Two parallel experiments were set up for each concentration gradient, and the average value was calculated to reduce errors and ensure data reliability. Detection method: Samples were taken at 0 min, 5 min, 10 min, 15 min, 20 min, 25 min, and 30 min of the reaction, covering the entire reaction time. After filtration through a 0.22 μm filter membrane, the absorbance was measured at 663.6 nm using a UV spectrophotometer, and quantification was performed using the characteristic absorption peak. The degradation rate at different time points was calculated, and the average value of the two parallel experiments was taken. Results are as follows: Figure 3 As shown, within the pH range of 3.0 to 9.0, changes in pH do not have a significant impact on the removal efficiency, indicating that the system is minimally affected by the pH of the water body and is suitable for real-world wastewater treatment.

[0040] Example 4

[0041] This embodiment uses the controlled variable method to achieve the same UV... 222 Under irradiation conditions and initial concentrations of dye and sodium perborate, different common inorganic ions and natural organic matter were added to the solution, and the degradation efficiency of methylene blue (MB) within the dye was compared over 30 minutes to determine whether the system could be used in actual wastewater treatment.

[0042] Prepare four 50 mL methylene blue solutions, each with a concentration of 10 mg / L. Add sodium perborate to the solutions to achieve a concentration of 1.0 mmol / L. Adjust the pH of all water samples to 7.0 ± 0.1 using appropriate amounts of 0.1 mol / L HCl and 0.1 mol / L KOH to maintain acid-base stability. Variable setting: Add appropriate amounts of Cl- to the system... - SO4 2- NO3 - HCO3 - Combine with natural humic substances (HA) to a concentration of 1 mmol / L (ion) or 1 mg / L (HA), and magnetically stir for 10 min at a stirring speed of 300 rpm to ensure uniform dispersion of the solute.

[0043] Reaction conditions: The same CTP-2000K plasma generator as in Example 1 was used. The electrode immersion depth was 2 cm, the voltage was adjusted to 60V, the current to 0.60A, and the reaction temperature to 25±2℃. Environmental variables were controlled. The stirring rate was 700 rpm to ensure uniform mixing of the reaction system. Two parallel experiments were set up for each concentration gradient, and the average value was calculated to reduce errors and ensure data reliability. Detection method: Samples were taken at 0 min, 5 min, 10 min, 15 min, 20 min, 25 min, and 30 min of the reaction, covering the entire reaction period. After filtration through a 0.22 μm filter membrane, the absorbance was measured at 663.6 nm using a UV spectrophotometer, and quantification was performed using the characteristic absorption peak. The degradation rate at different time points was calculated, and the average value of the two parallel experiments was taken.

[0044] The results are as follows Figure 4 As shown, Cl - SO4 2- HCO3 - The effects of humus on the system are minimal; the dye degradation rate can still reach over 95% after 30 minutes. NO3 - It showed a certain inhibitory effect, with the dye degradation rate reaching 84% after 30 minutes.

[0045] Example 5

[0046] This embodiment uses the controlled variable method to achieve the same UV... 222 Under irradiation conditions and initial sodium perborate concentration, different dye concentrations were set, and the degradation efficiency of methylene blue (MB) within 30 minutes was compared to determine the degradation effect of the system on different concentrations of MB.

[0047] Variable settings: Prepare four 50 mL methylene blue solutions with concentrations of 5, 10, 15, and 20 mg / L. Add sodium perborate to the solutions to achieve a concentration of 1.0 mmol / L. Adjust the pH of all water samples to 7.0 ± 0.1 using appropriate amounts of 0.1 mol / L HCl and 0.1 mol / L KOH to maintain acid-base stability. Stir magnetically for 10 min at a stirring speed of 300 rpm to ensure uniform solute dispersion.

[0048] Reaction conditions: The same CTP-2000K plasma generator as in Example 1 was used. The electrode immersion depth was 2 cm, the reaction temperature was 25 ± 2 °C, and environmental variables were controlled. The stirring rate was 700 rpm to ensure uniform mixing of the reaction system. Two parallel experiments were set up for each concentration gradient, and the average value was calculated to reduce errors and ensure data reliability. Detection method: Samples were taken at 0 min, 5 min, 10 min, 15 min, 20 min, 25 min, and 30 min of the reaction, covering the entire reaction period. After filtration through a 0.22 μm filter membrane, the absorbance was measured at 663.6 nm using a UV spectrophotometer, and quantification was performed using the characteristic absorption peak. The degradation rate at different time points was calculated, and the average value of the two parallel experiments was taken.

[0049] The results are as follows Figure 5 As shown, when the MB concentration is 5–20 mg / L, the degradation rate can reach over 90% within 30 minutes.

[0050] Example 6

[0051] This embodiment uses the controlled variable method to achieve the same UV... 222 Under irradiation conditions and initial sodium perborate concentration, different types of dyes were used, and the degradation efficiency of different dyes was compared after 30 minutes to determine the applicability of the system.

[0052] Variable settings: Prepare five 50 mL solutions of MB, methyl orange (MO), methyl violet (MV), malachite green (MG), and rhodamine B (RhB), each with a concentration of 10 mg / L. Add sodium perborate to the solutions to achieve a concentration of 1.0 mmol / L. Adjust the pH of all water samples to 7.0 ± 0.1 using appropriate amounts of 0.1 mol / L HCl and 0.1 mol / L KOH to maintain acid-base stability. Stir magnetically for 10 min at a stirring speed of 300 rpm to ensure uniform solute dispersion.

[0053] Reaction conditions: The same CTP-2000K plasma generator as in Example 1 was used. The electrode immersion depth was 2 cm, the voltage was adjusted to 60V, the current to 0.60A, the reaction temperature to 25±2℃, and environmental variables were controlled. The stirring rate was 700 rpm to ensure uniform mixing of the reaction system. Two parallel experiments were set up for each concentration gradient, and the average value was calculated to reduce errors and ensure data reliability. Detection method: Samples were taken at appropriate time points during the reaction, covering the entire reaction period. After filtration through a 0.22 μm filter membrane, the absorbance of the corresponding dye solution was measured at 663.6 nm, 463.2 nm, 583.4 nm, 616.8 nm, and 552.2 nm using a UV spectrophotometer, and quantification was performed using characteristic absorption peaks. The degradation rate at different time points was calculated, and the average value of the two parallel experiments was taken.

[0054] See results Figure 6 This indicates that the combined system is applicable to all of the aforementioned dyes.

[0055] The above embodiments are merely preferred embodiments of the present invention and should not be considered as limiting the scope of the present invention. All equivalent variations and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A method of using UV 222 The method for jointly degrading common dyes in wastewater by sodium perborate is characterized by The method comprises the following steps: 1) adding sodium perborate with a concentration of no more than 2.0 mM into a water body containing dyes to be degraded; 2) using a plasma generator to generate UV 222 to irradiate the water body; 3) controlling the reaction conditions: pH 3.0-9.0, reaction time ≤ 40 min, to realize efficient degradation of the dyes.

2. A method according to claim 1 using UV 222 The method for jointly degrading common dyes in wastewater by sodium perborate is characterized by comprising the following steps In step 1), the concentration of the sodium perborate is 0.2-1.4 mM.

3. The use of UV 222 The method for jointly degrading common dyes in wastewater by sodium perborate is characterized by In step 1), the concentration of the dyes to be degraded is 5-20 mg / L.

4. The use of UV 222 The method for jointly degrading common dyes in wastewater by sodium perborate is characterized by In step 2), the UV is generated by a plasma generator 222 The water body is irradiated by a dielectric barrier discharge type AC power source; the electrode structure includes a high-voltage electrode and a ground electrode, the electrode material is copper and iron, and the spectral purity is greater than 95%; the power of the plasma generator is 70 W, and the power of the lamp is 20 W.

5. A method of using UV 222 The method for jointly degrading common dyes in wastewater by sodium perborate is characterized by In step 3), the reaction time is 30 min.

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