A method for treating organic pollutants in wastewater by using a pre-oxidation activation method to strengthen iron-based amorphous alloy

Abstract

The application discloses a method for treating organic pollutants in wastewater by using a pre-oxidation activation method to strengthen iron-based amorphous alloy, and belongs to the technical field of wastewater treatment. The method comprises the following steps: heating wastewater containing organic pollutants, adding hydrogen peroxide, adjusting pH, then adding pre-oxidized iron-based amorphous alloy, and stirring to react and degrade the organic pollutants. The method has the advantages of low requirement for pre-oxidation equipment, simple operation, strong practicability, continuous treatment of iron-based amorphous alloy in batches, and convenience for popularization and industrialization, and has very important significance for realizing water resource recycling, environmental governance, energy saving and emission reduction, and sustainable development.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sewage treatment, and particularly relates to a method for treating organic pollutants in wastewater by using a pre-oxidation activation method to strengthen iron-based amorphous alloy. BACKGROUND

[0002] Due to the complex molecular structure and high chemical stability, it is difficult to treat azo dyes in industrial wastewater by traditional biological degradation methods. These dyes may be converted into carcinogenic aromatic amines under anaerobic conditions through the action of microorganisms, increasing the environmental and health risks. At present, the methods for treating azo dye-containing wastewater mainly include physical methods, biological methods and chemical methods. Physical methods such as activated carbon adsorption can separate dyes but cannot degrade azo dyes, and have high operating costs and generate a large amount of sludge that needs to be treated. Biological methods are suitable for the degradation of specific toxic azo dyes, but have a narrow application range. Chemical methods are favored due to their fast degradation rate and high degradation rate, especially the advanced oxidation method, which generates active free radicals to degrade pollutants.

[0003] Among the chemical methods, zero-valent iron reduction method and its coupled Fenton oxidation method are effective methods for treating azo dye-containing wastewater. These methods use hydroxyl radicals generated by Fenton reaction to degrade azo dyes to generate non-toxic small molecules. However, the degradation efficiency of these methods is easily affected by the environment, has poor stability, and requires a long time to achieve efficient degradation. Pre-oxidation methods such as ball milling, increasing specific surface area, and annealing can improve the active sites of zero-valent iron and accelerate the degradation of azo dyes, but there is still a certain gap from industrial application.

[0004] Patent CN113201699B discloses an iron-based alloy material and its preparation method and application. The material contains Fe, Si, B, P and C elements, and is used for the degradation treatment of azo dye wastewater. However, the alloy composition in this patent is strictly required, Fe: 82%~83%, Si: 2%~3%, B: 10%~15%, P: 2%~3%, C: 1%, and the iron-based alloy prepared in this patent needs to be annealed at a high temperature of 800~850℃ in a vacuum to form nanocrystals. High-temperature annealing requires high requirements for heat treatment equipment and conditions, increasing the cost. In addition, the dosage of the iron-based alloy material in this patent is 2g / L, and the C1 material is preferred. It still takes more than 30min to achieve a degradation rate of 90% (C t / C0 equals 0.1) in the degradation of 40mg / L orange II solution.

[0005] Patent CN109402369A discloses an iron-based porous material for degrading azo dyes and its preparation method. The porous material is obtained by heat-treating an iron-based amorphous alloy precursor and then using dealloying. However, this method requires a high vacuum of 80 mTorr during the heat treatment process, and the concentration and treatment time of the etching solution must be strictly controlled during the dealloying process. Furthermore, the patent only provides the final degradation rate of the porous material for degrading azo dyes, without providing the degradation reaction rate or reaction constant.

[0006] Patent CN117943002A discloses an iron-based nanoporous material, its preparation method, and its application. The iron-based nanoporous material is prepared through annealing and chemical dealloying. However, this method still requires approximately 30 minutes to achieve a degradation rate exceeding 90% under the following conditions: an 8g / L dosage of np-SA20, a 40mg / L Golden Orange II solution concentration, and a constant temperature of 35°C.

[0007] Patent CN110918911B discloses an iron-based amorphous alloy strip and its use in the degradation of azo dye wastewater. Although the alloy strip exhibits excellent corrosion resistance and catalytic degradation activity, the degradation rate of the alloy prepared by this method, using 2 g / L of the strip, is less than 50% after 10 minutes when degrading 40 mg / L of azo dye, and it takes another 50 minutes to achieve a degradation rate exceeding 95%.

[0008] Patent CN111170414B discloses a method for degrading wastewater with an iron-based amorphous alloy strip. The degradation rate is increased by ball milling the iron-based amorphous alloy strip for 4-8 hours. When the strip dosage is 10g / L and the pH is 2-3, it still takes more than 10 minutes to achieve a degradation rate of 90% for the degradation of 20mg / L of Acid Orange 7. (C t / C0 equals 0.1).

[0009] Patent CN112973691B discloses a method for preparing an amorphous-nanocrystalline alloy with a nanostructure, which increases the reaction rate by increasing the specific surface area of ​​the strips. However, the examples show that the degradation rate of organic dye waste liquid with the addition of 0.5g / L nanocrystalline alloy catalyst is only 50% after 6 minutes of reaction, while it takes more than 30 minutes to achieve a degradation rate of 97%.

[0010] Patent CN107326159B discloses a method for preparing and applying an iron-based nanocrystalline alloy for treating azo dye-containing printing and dyeing wastewater. The method obtains iron-based nanocrystals by annealing an iron-based amorphous alloy. However, when annealing the 1K107BN85 strips obtained by this method at 800°C, it still takes 10-15 minutes to achieve a degradation rate of 90% for a 25 mg / L aqueous solution of Golden Orange 2 dye at a strip dosage of 10 g / L.

[0011] At present, the efficiency of using iron-based amorphous alloys to degrade printing and dyeing wastewater is still relatively low. The time to complete a 90% degradation rate is generally more than 10 minutes, and the equipment requirements are high, the processing time is long, and the preparation method is relatively complex. It is difficult to meet the needs of low-cost rapid activation of iron-based amorphous-nanocrystalline alloys, and thus achieve rapid degradation of organic pollutants in wastewater. Summary of the Invention

[0012] The present invention aims to provide a method for treating organic pollutants in wastewater using an iron-based amorphous alloy enhanced by a pre-oxidation activation method, thereby overcoming the problems of the prior art. The pre-oxidation-treated iron-based amorphous alloy is added to the wastewater system to degrade the organic pollutants in the wastewater. The pre-oxidation treatment method involves short-term, high-temperature oxidation. This method has the advantages of being simple, highly efficient, and time-efficient in degrading organic pollutants in wastewater, as well as being able to operate continuously and treat a variety of organic pollutants.

[0013] A method for treating organic pollutants in wastewater by using a pre-oxidation activation method to strengthen an iron-based amorphous alloy comprises the following steps: heating the wastewater containing the organic pollutants, adding hydrogen peroxide, adjusting the pH, then adding a pre-oxidized iron-based amorphous alloy, reacting under stirring, and degrading the organic pollutants.

[0014] Preferably, the concentration of the organic pollutants in the wastewater is 5-350 mg / L, the amount of hydrogen peroxide added is 1-30 mmol / L, and the amount of the pre-oxidized iron-based amorphous alloy added is 0.05-20 g / L.

[0015] Preferably, the pre-oxidized iron-based amorphous alloy is obtained by subjecting the iron-based amorphous alloy to a high-temperature oxidation treatment in air or an atmosphere with an oxygen partial pressure of not less than 0.01 MPa.

[0016] More preferably, the temperature of the high-temperature oxidation is 450-850° C., and the time is 6 seconds to 30 minutes.

[0017] More preferably, the temperature of the high-temperature oxidation is 500-800°C.

[0018] Most preferably, the temperature of the high temperature oxidation is 650-750°C.

[0019] More preferably, the iron-based amorphous alloy includes one or more of amorphous strips newly prepared by casting or melting, strips with partially aged and crystallized surfaces, and waste strips with rusted and oxidized surfaces, and the iron-based amorphous alloy includes silicon, boron and iron, wherein the mass percentage of iron atoms is ≥50%.

[0020] The present invention utilizes high-temperature oxidation treatment of iron-based amorphous alloys, and the principle of strengthening the iron-based amorphous degradation of organic pollutants in wastewater is as follows: during the pre-oxidation treatment of the iron-based amorphous alloy, on the one hand, the oxidation treatment causes the silicon and boron elements inside the iron-based amorphous alloy to diffuse rapidly, forming submicron silicon-rich and boron-rich iron oxide particles on the surface of the strip, thereby increasing the specific surface area of ​​the strip. On the other hand, the iron element inside the strip is precipitated to form nano- or submicron α-Fe that spreads throughout the surface and interior of the alloy, increasing crystal defects such as grain boundaries and phase boundaries inside the alloy, changing the chemical potential on the surface and interior of the strip, and thus promoting the catalytic degradation rate of the alloy; in addition, during the pre-oxidation treatment, the segregation of silicon and boron elements in the iron-based amorphous alloy introduces residual stress and a passivation film inside the strip, thereby facilitating the iron atoms to lose electrons to generate ferrous ions that enter the solution, further promoting the generation of hydroxyl radicals and the degradation rate of organic pollutants.

[0021] Preferably, the heating temperature is 10-80°C, the pH is 2.0-6.5, and the stirring time is 10s-30min. More preferably, the pH is 2.5-5.0, and even more preferably, the pH is 2.9-4.5.

[0022] Preferably, the organic pollutants include one or more organic substances such as Orange II, methylene blue, rhodamine B and phenol.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects:

[0024] The high-temperature rapid pre-oxidation activation method has an enhancing effect on common commercially available iron-based amorphous alloys and iron-based amorphous alloy strips with partially aged, rusted, and oxidized surfaces. In catalytic degradation experiments conducted under a Fenton-like system, using 0.5 g / L pre-oxidized iron-based amorphous strips, the degradation rate of Orange II was about 95% in just 2 minutes, while the degradation rate of Rhodamine B required 6 minutes of reaction time to achieve a 95% degradation rate.

[0025] Compared with other surface activation (treatment) methods for iron-based amorphous materials, such as high-temperature vacuum annealing, surface activation, and dealloying, the pre-oxidation activation method provided by the present invention has a significant effect on enhancing the degradation of azo dyes by amorphous alloys and is low in cost. According to calculations, the pre-oxidation cost of iron-based amorphous alloys required for degrading printing and dyeing wastewater containing azo dyes using this method is less than 0.5 yuan per ton of wastewater.

[0026] The method provided by the present invention has low requirements for pre-oxidation equipment, is simple to operate, has strong practicality, can continuously and batch-process iron-based amorphous alloys, is easy to promote and industrialize, and is of great significance for achieving water resource recycling, environmental governance, energy conservation and emission reduction, and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 (a) is the UV-visible absorption spectrum measured in Example 1, and (b) is the UV-visible absorption spectrum measured in Example 2;

[0029] Figure 2 The degradation rate of the 1k107 iron-based amorphous ribbon activated by pre-oxidation at 650°C in Example 1-2 degrades 20 mg / L Orange II and Rhodamine B dye aqueous solutions respectively over time;

[0030] Figure 3 This is a graph showing the color change of the Orange II dye aqueous solution over time in Example 1;

[0031] Figure 4 This is a graph showing the color change of the Rhodamine B dye aqueous solution over time in Example 2;

[0032] Figure 5 (a) is the ultraviolet-visible absorption spectrum measured in Example 3, (b) is the ultraviolet-visible absorption spectrum measured in Example 4, and (c) is the ultraviolet-visible absorption spectrum measured in Example 12;

[0033] Figure 6 (a) is the UV-visible absorption spectrum measured in Example 13, and (b) is the UV-visible absorption spectrum measured in Example 5;

[0034] Figure 7 (a) is the ultraviolet-visible absorption spectrum measured in Example 6, (b) is the ultraviolet-visible absorption spectrum measured in Example 7, and (c) is the ultraviolet-visible absorption spectrum measured in Example 8;

[0035] Figure 8 (a) is the UV-visible absorption spectrum measured in Example 9, and (b) is the UV-visible absorption spectrum measured in Comparative Example 1;

[0036] Figure 9 This is the UV-visible absorption spectrum obtained in Comparative Example 2;

[0037] Figure 10 This is a graph showing the degradation rate of the Orange II dye aqueous solution in Example 3;

[0038] Figure 11 This is a graph showing the degradation rate of the Orange II dye aqueous solution in Example 4;

[0039] Figure 12 This is a graph showing the degradation rate of the Orange II dye aqueous solution in Example 5;

[0040] Figure 13 This is a graph showing the degradation rate of the Orange II dye aqueous solution in Example 6;

[0041] Figure 14 This is a graph showing the degradation rate of the Orange II dye aqueous solution in Example 7;

[0042] Figure 15 This is a graph showing the degradation rate of the Orange II dye aqueous solution in Example 8;

[0043] Figure 16 This is a graph showing the degradation rate of the Orange II dye aqueous solution in Example 9;

[0044] Figure 17 This is a graph showing the degradation rate of the Orange II dye aqueous solution in Example 12;

[0045] Figure 18 This is a graph showing the degradation rate of the Orange II dye aqueous solution in Example 13;

[0046] Figure 19 (a) is the UV-visible absorption spectrum measured in Example 10, and (b) is the degradation rate versus time curve of the 1k107 iron-based amorphous ribbon pre-oxidized and activated at 650°C in Example 10 when degrading a 20 mg / L Orange II aqueous solution;

[0047] Figure 20 (a) is the UV-visible absorption spectrum measured in Example 11, and (b) is the degradation rate curve of 1k107 iron-based amorphous strips activated by pre-oxidation at 750°C in Example 11 when degrading 20 mg / L Orange II aqueous solution. DETAILED DESCRIPTION

[0048] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0049] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0050] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0051] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0052] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0053] An embodiment of the present invention provides a method for treating organic pollutants in wastewater by using a pre-oxidation activation method to strengthen an iron-based amorphous alloy, comprising the following steps: heating the wastewater containing organic pollutants, adding hydrogen peroxide, adjusting the pH, and then adding a pre-oxidized iron-based amorphous alloy, reacting under stirring to degrade the organic pollutants.

[0054] In some embodiments, the concentration of the organic pollutants in the wastewater is 5-350 mg / L, the amount of hydrogen peroxide added is 1-30 mmol / L, and the amount of the pre-oxidized iron-based amorphous alloy added is 0.05-20 g / L.

[0055] In some preferred embodiments, the amount of the pre-oxidized iron-based amorphous alloy added is 0.5-10 g / L. Exemplarily, the amount of the pre-oxidized iron-based amorphous alloy added is 0.5 g / L or 10 g / L.

[0056] In some embodiments, the pre-oxidized iron-based amorphous alloy is obtained by subjecting the iron-based amorphous alloy to a high-temperature oxidation treatment in air or an atmosphere with an oxygen partial pressure of not less than 0.01 MPa.

[0057] In some embodiments, the high temperature oxidation temperature is 450-850° C., and the time is 6 seconds to 30 minutes.

[0058] In some preferred embodiments, the temperature of the high temperature oxidation is 500-800°C.

[0059] In some more preferred embodiments, the temperature of the high temperature oxidation is 650-750°C.

[0060] In some embodiments, the iron-based amorphous alloy includes one or more of newly prepared amorphous strips by casting or melting, strips with partially aged and crystallized surfaces, and waste strips with rusted and oxidized surfaces. The iron-based amorphous alloy includes silicon, boron and iron, wherein the mass percentage of iron atoms is ≥50%.

[0061] In some preferred embodiments of the present invention, the heating temperature is 10-80° C., the pH is 2.0-6.5, and the stirring time is 10 s-30 min.

[0062] In some preferred embodiments, the heating temperature is 10-70°C.

[0063] In some preferred embodiments, the pH is 2.5-5.0;

[0064] In some more preferred embodiments, the pH is 2.9-4.5.

[0065] In some preferred embodiments of the present invention, the organic pollutants include one or more organic substances such as Orange II, methylene blue, rhodamine B and phenol.

[0066] Normal temperature in the present invention refers to 25±2°C.

[0067] Example 1

[0068] 1) Place 0.125g of Fe-based amorphous 1K107 ribbon in air at 650°C and let it stand for 5 minutes for pre-oxidation. Take out the pre-oxidized Fe-based amorphous ribbon and cool it in air for later use.

[0069] 2) Take 250mL of 20mg / L Orange II (Acid Orange 7, AO7) aqueous solution was placed in a 500 mL beaker, which was placed in a 30°C water bath, and 3 mmol / L hydrogen peroxide was added (3 mmol hydrogen peroxide was added per liter of wastewater). The pH value was adjusted to 3 by adding 5% by mass dilute sulfuric acid solution. The Orange II solution was mechanically stirred at 600 r / min, and 0.5 g / L pre-oxidized iron-based amorphous alloy strips were added. 4.8 mL of Orange II solution was collected at 0 s, 30 s, 60 s, 90 s, 2 min, 3 min, 4 min, and 6 min after the addition of the strips. The samples were filtered through a 0.22 μm aqueous polyethersulfone (PES) membrane, and the solution spectrum was measured by UV-visible photometer. The color change of the dye solution over time was recorded by photographing at 0 min, 0.5 min, 1.0 min, 1.5 min, 2.5 min, 4.0 min, 6.0 min, and 9.0 min. The degradation rate of Orange II in the solution at different times was calculated and the degradation rate curve was drawn.

[0070] Figure 1 (b) UV-Vis absorption spectrum of 1k107 iron-based amorphous ribbon measured in Example 2, Figure 2 Figure 2 shows the degradation rate of 20 mg / L Orange II and Rhodamine B aqueous solution with time when 1k107 iron-based amorphous ribbon activated by pre-oxidation at 650°C in Example 1-2 respectively; Figure 2 It can be seen from Figure 2 that the degradation of Orange II has been basically completed after 2 min of reaction under the above degradation conditions, and the degradation rate is 93.5%. The degradation rate of Orange II reaches 98.4% after 3 min of degradation, and the degradation rate of Orange II reaches 99.5% after 6 min of degradation.

[0071] Figure 3 Figure 3 shows the color change of Orange II dye aqueous solution with time in Example 1, from Figure 3 It can be seen from Figure 3 that it has completely changed into colorless transparent state at 6 min.

[0072] Example 2

[0073] The same as Example 1, the only difference is that the Orange II aqueous solution is replaced by Rhodamine B aqueous solution, and 4.8 mL of Rhodamine B solution is taken at 0 s, 30 s, 60 s, 90 s, 150 s, 4 min, 6 min, 9 min and 12 min after the addition of the pre-oxidized iron-based amorphous alloy strip, respectively, filtered through a 0.22 μm water-based polyether sulfone (PES) filter membrane, the solution spectrum is measured by a UV-visible spectrophotometer, and the color change of the dye solution with time is recorded by taking pictures at 0 min, 0.5 min, 1.0 min, 1.5 min, 2.5 min, 4.0 min, 6.0 min, 9.0 min and 12.0 min. The degradation rate of Rhodamine B in the solution at different times is calculated and the degradation rate curve is drawn.

[0074] Figure 1 (b) UV-Vis absorption spectrum of 1k107 iron-based amorphous ribbon measured in Example 2, combined with Figure 2 It can be seen from Figure 4 that the degradation of Rhodamine B has been basically completed after 6 min of degradation under the above degradation conditions, and the degradation rate is 98.1%. The degradation rate of Rhodamine B reaches 99.7% after 12 min of reaction, and the color completely disappears, as shown in Figure 4 Figure 5 shows the color change of Rhodamine B dye aqueous solution with time in Example 2.

[0075] Example 3

[0076] The same as example 1, the only difference is that step 2): 250 mL of orange II aqueous solution with a concentration of 150 mg / L is placed in a 500 mL beaker, the beaker is placed in a 40℃ water bath box, 12 mmol / L of hydrogen peroxide is added, and the pH value is adjusted to 2.9; the orange II solution is mechanically stirred at 350 r / min, 2 g / L of pre-oxidized iron-based amorphous alloy strip is added, and 4.8 mL of orange II solution is taken at 0 s, 30 s, 60 s, 90 s, 150 s, 4 min, 6 min, and 9 min after the strip is added, respectively, filtered through a 0.22 μm water-based polyether sulfone (PES) filter membrane, the solution spectrum is measured using a UV-visible spectrophotometer, the color change of the dye solution with time is recorded by taking pictures, and the degradation rate of orange II in the solution at different times is calculated and the degradation rate curve is drawn.

[0077] Figure 5 (a) in FIG. 1 is the UV-visible absorption spectrum measured in example 1, Figure 10 FIG. 2 is the degradation rate curve of the orange II dye aqueous solution in example 1, and the degradation rate of orange II under this degradation condition is 92.9% after 2.5 min of reaction, and the degradation rate reaches 99.3% after 9 min. At 9 min, the color completely disappears.

[0078] Example 4

[0079] The same as example 1, the only difference is that the 30℃ water bath box is replaced by a 10℃ water bath box, and 4.8 mL of orange II solution is taken at 0 min, 1 min, 2.5 min, 4 min, 6 min, 9 min, 12 min and 18 min after the strip is added, respectively, filtered through a 0.22 μm water-based polyether sulfone (PES) filter membrane, the solution spectrum is measured using a UV-visible spectrophotometer, the degradation rate of orange II in the solution at different times is calculated and the degradation rate curve is drawn.

[0080] Figure 5 (b) in FIG. 3 is the UV-visible absorption spectrum measured in example 4, Figure 11 FIG. 4 is the degradation rate curve of the orange II dye aqueous solution in example 4, and the degradation rate of orange II under this degradation condition is 83.1% after 9 min of reaction, and the degradation rate reaches 92.8% after 18 min.

[0081] Example 5

[0082] The same as example 1, the only difference is that the high-temperature oxidation treatment condition is changed from 650℃ oxidation for 5 min to 580℃ oxidation for 5 min.

[0083] Figure 6 (b) in FIG. 5 is the UV-visible absorption spectrum measured in example 5, Figure 12This is a degradation curve of the Orange II dye aqueous solution in Example 5. Under the degradation conditions, the degradation rate of Orange II is 87.3% after 6 minutes of reaction. After 9 minutes, the degradation rate reaches 93%.

[0084] Example 6

[0085] 1) Place 0.125g of Fe-based amorphous 1K101 ribbon in air at 530°C and let it stand for 5 minutes for pre-oxidation. Take out the pre-oxidized Fe-based amorphous ribbon and cool it in air for later use.

[0086] 2) Place 250 mL of a 20 mg / L Orange II aqueous solution in a 500 mL beaker. Place the beaker in a 30°C water bath and add 3 mmol / L hydrogen peroxide to adjust the pH to 2.9. Mechanically stir the Orange II solution at 350 rpm. Add 0.5 g / L of pre-oxidized iron-based amorphous ribbons. Collect 4.8 mL of the Orange II solution at 0 s, 30 s, 60 s, 90 s, 150 s, 4 min, 6 min, and 9 min after the addition of the ribbons. Filter the solution through a 0.22 μm aqueous polyethersulfone (PES) membrane. Measure the solution spectrum using a UV-visible photometer. Take photos to record the color change of the dye solution over time. Calculate the degradation rate of Orange II in the solution at different times and plot the degradation rate curve.

[0087] Figure 7 (a) is the UV-visible absorption spectrum measured in Example 6, Figure 13 This is a degradation curve of the Orange II dye aqueous solution in Example 6. Under the degradation conditions, the degradation rate of Orange II is 96% after 1.5 minutes of reaction. After 9 minutes, the degradation rate reaches 99%.

[0088] Example 7

[0089] The same as Example 6, except that the high-temperature oxidation treatment condition is changed from oxidation at 530° C. for 5 min to oxidation at 800° C. for 1 min.

[0090] Figure 7 (b) is the UV-visible absorption spectrum measured in Example 7, Figure 14 This is a degradation curve of the Orange II dye aqueous solution in Example 7. Under the degradation conditions, the degradation rate of Orange II is 95.9% after 4 minutes of reaction. After 9 minutes, the degradation rate reaches 99.9%.

[0091] Example 8

[0092] The same as Example 6, except that the high-temperature oxidation treatment condition is changed from oxidation at 530° C. for 5 min to oxidation at 460° C. for 5 min.

[0093] Figure 7(c) is the UV-visible absorption spectrum measured in Example 8, Figure 15 This is a degradation rate curve of the Orange II dye aqueous solution in Example 8. Under the degradation conditions, the degradation rate of Orange II is 92.5% after 4 minutes of reaction. After 9 minutes, the degradation rate reaches 98.9%.

[0094] Example 9

[0095] 1) Place 0.25g of Fe-based amorphous 1K107 ribbon in air at 200°C and let it stand for 20 minutes to simulate the state of 1K107 ribbon in service for 5-10 years at room temperature. Remove the oxidized Fe-based amorphous ribbon and cool it in air for later use.

[0096] 2) Place 0.125 g of the simulated waste ribbon from step 1) in air at 650°C and allow to stand for 5 minutes for pre-oxidation activation. Remove the activated iron-based amorphous ribbon and cool it in air for later use.

[0097] 3) Take 250 mL of a 20 mg / L Orange II aqueous solution and place it in a 500 mL beaker. Place the beaker in a 30°C water bath and add 3 mmol / L hydrogen peroxide to adjust the pH to 3.

[0098] 4) Mechanically stir the Orange II solution at 350 rpm and add 0.125 g of the activated strip (0.5 g / L) from step 2). Take 4.8 mL of the Orange II solution at 0 s, 30 s, 60 s, 90 s, 150 s, 4 min, 6 min, and 9 min after the addition of the strip. Filter through a 0.22 μm aqueous polyethersulfone (PES) membrane and measure the solution spectrum using a UV-visible photometer. Calculate the degradation rate of Orange II in the solution at different times and plot the degradation rate curve.

[0099] Figure 8 (a) is the UV-visible absorption spectrum measured in step 4), Figure 16 This is a graph showing the degradation rate of the Orange II dye aqueous solution in Example 9. Under the degradation conditions, the degradation rate of Orange II is 88.1% after 2.0 minutes of reaction. After 9 minutes, the degradation rate reaches 99.2%.

[0100] Example 10

[0101] 1) Place 2.5280g of Fe-based amorphous 1K107 ribbon in air at 650℃ and let it stand for 3 minutes for pre-oxidation. Take out the pre-oxidized Fe-based amorphous ribbon and cool it in air for later use.

[0102] 2) Place 250 mL of a 20 mg / L Orange II (Acid Orange 7, AO7) aqueous solution in a 500 mL beaker. Place the beaker in a 30°C water bath and add 3 mmol / L hydrogen peroxide (3 mmol hydrogen peroxide per liter of wastewater). Adjust the pH to 2.8 by adding a 5% (mass fraction) dilute sulfuric acid solution. Mechanically stir the Orange II solution at 600 rpm. Add 10 g / L of pre-oxidized iron-based amorphous alloy ribbons. At 0 s, 30 s, 60 s, 90 s, 2 min, 3 min, and 4 min after the addition of the ribbons, collect 4.8 mL of the Orange II solution. Filter through a 0.22 μm aqueous polyethersulfone (PES) membrane. Measure the solution spectrum using a UV-visible photometer. Calculate the degradation rate of Orange II in the solution at different times, and plot the degradation rate curve.

[0103] Figure 19 (a) is the UV-visible absorption spectrum measured in Example 10, Figure 19 (b) is a curve showing the degradation rate of the 1k107 iron-based amorphous ribbon pre-oxidized and activated at 650°C in Example 10 when degrading a 20 mg / L Orange II aqueous solution; Figure 19 (b) shows that Orange II (AO7) has been basically degraded under the above degradation conditions after 1 minute of reaction, with a degradation rate of 98.0%. The degradation rate of Orange II reaches 98.5% after 2 minutes of degradation.

[0104] Example 11

[0105] 1) Place 0.1316g of Fe-based amorphous 1K107 ribbon in air at 750°C and let it stand for 1 minute for pre-oxidation. Take out the pre-oxidized Fe-based amorphous ribbon and cool it in air for later use.

[0106] 2) 250 mL of a 20 mg / L Orange II (Acid Orange 7, AO7) aqueous solution was placed in a 500 mL beaker. The beaker was placed in a 30°C water bath and 3 mmol / L of hydrogen peroxide was added (3 mmol of hydrogen peroxide was added per liter of wastewater). The pH value was adjusted to 4.1 by adding a 5% (mass fraction) dilute sulfuric acid solution. The Orange II solution was mechanically stirred at 600 rpm. 0.5 g / L of pre-oxidized iron-based amorphous alloy ribbons was added. 4.8 mL of Orange II solution was collected at 0 s, 30 s, 60 s, 90 s, 2.5 min, 4 min, 6 min, and 9 min after the addition of the ribbons. The solution was filtered through a 0.22 μm aqueous polyethersulfone (PES) membrane and the solution spectrum was measured using a UV-visible photometer. The degradation rate of Orange II in the solution at different times was calculated and the degradation rate curve was plotted.

[0107] Figure 20(a) is the UV-visible absorption spectrum measured in Example 11, Figure 20 (b) is a curve showing the degradation rate versus time of the 1k107 Fe-based amorphous ribbon pre-oxidized and activated at 750°C in Example 11 when degrading a 20 mg / L Orange II aqueous solution; Figure 20 (b) shows that the degradation rate of Orange II (AO7) is 86.7% after 4 minutes of reaction under the above degradation conditions. After 9 minutes, its degradation rate reaches 97.8%.

[0108] Example 12

[0109] The same as Example 1, except that the pH of the solution was adjusted to 4.5 instead of 3.0, and 4.8 mL of Orange II solution was taken at 0 s, 0.5 min, 1 min, 1.5 min, 2.5 min, 4 min, 6 min, 9 min, 13 min, 18 min, and 25 min after the strip was added. The solution was filtered through a 0.22 μm aqueous polyethersulfone (PES) filter membrane, and the solution spectrum was measured using a UV-visible photometer.

[0110] Figure 5 (c) is the UV-visible absorption spectrum measured in Example 12. Figure 17 This is a graph showing the degradation rate of the Orange II dye aqueous solution in Example 12. The degradation rate of Orange II is 53% after 25 minutes of reaction under the degradation conditions.

[0111] Example 13

[0112] The same as Example 1, except that, in step 1): the high-temperature oxidation treatment condition is replaced from 650°C oxidation for 5 min to 850°C oxidation for 1 min, and in step 2): the sampling time is changed to 0 min, 1 min, 3 min, 5 min, 9 min, 13 min, 18 min, and 25 min.

[0113] Figure 6 (a) is the UV-visible absorption spectrum measured in Example 13, Figure 18 This is a graph showing the degradation rate of the Orange II dye aqueous solution in Example 13. The degradation rate of Orange II is 37% after 25 minutes of reaction under the degradation conditions.

[0114] Comparative Example 1

[0115] 1) Place 0.25g of Fe-based amorphous 1K107 ribbon in air at 200°C and let it stand for 20 minutes to simulate the state of 1K107 ribbon in service for 5-10 years at room temperature. Remove the oxidized Fe-based amorphous ribbon and cool it in air for later use as a simulated long-term service waste (aged) amorphous ribbon.

[0116] 2) Place 250 mL of a 20 mg / L Orange II aqueous solution in a 500 mL beaker. Place the beaker in a 30°C water bath and add 3 mmol / L hydrogen peroxide to adjust the pH to 3.

[0117] 3) The Orange II solution was mechanically stirred at 350 rpm, and 0.125 g of the simulated long-term service waste (aged) amorphous strip (0.5 g / L) from step 1) was added. 4.8 mL of the Orange II solution was collected at 0 min, 1 min, 3 min, 5 min, 9 min, 13 min, 18 min, and 25 min after the strip was added. The solution was filtered through a 0.22 μm aqueous polyethersulfone (PES) membrane, and the solution spectrum was measured using a UV-visible photometer. The degradation rate of Orange II in the solution at different times was calculated, and the degradation rate curve was plotted.

[0118] Figure 8 (b) shows the UV-visible absorption spectrum obtained in Comparative Example 1. It shows that Orange II does not begin to degrade within the first 25 minutes under these degradation conditions. Compared to Example 9, this indicates that the degradation capacity of the iron-based amorphous ribbon, which has been in service for 5-10 years at room temperature, is relatively poor. However, after high-temperature oxidation treatment at 650°C in air for 5 minutes, its degradation capacity is significantly improved.

[0119] Comparative Example 2

[0120] 1) Place 250 mL of a 20 mg / L Orange II aqueous solution in a 500 mL beaker. Place the beaker in a 30°C water bath and add 3 mmol / L hydrogen peroxide to adjust the pH to 3.

[0121] 2) The Orange II solution was mechanically stirred at 350 rpm, and 0.125 g of iron-based amorphous 1K107 ribbon (0.5 g / L) was added. 4.8 mL of the Orange II solution was collected at 0 min, 1 min, 3 min, 5 min, 9 min, 13 min, 18 min, 25 min, and 90 min after the addition of the ribbon. The solution was filtered through a 0.22 μm aqueous polyethersulfone (PES) membrane and the solution spectrum was measured using a UV-visible photometer. The degradation rate of Orange II in the solution at different times was calculated, and the degradation rate curve was plotted.

[0122] Figure 9The UV-visible absorption spectrum obtained in Comparative Example 2 shows that Orange II dye has an absorption peak at 485 nm, which is used to calculate the degradation rate of Orange II dye. It can be seen that Orange II does not begin to degrade within the first 25 minutes under these degradation conditions. After 90 minutes of reaction, the degradation rate of Orange II is only 72.2%. Compared with Example 1, this indicates that the iron-based amorphous ribbons, which have not been strengthened by high-temperature oxidation treatment, have relatively poor Orange II degradation capabilities. Even at a low concentration (20 mg / L) of the azo dye, degradation still takes a long time, and degradation is incomplete, failing to achieve a degradation rate exceeding 99%.

[0123] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for treating organic pollutants in wastewater by strengthening iron-based amorphous alloys using a pre-oxidation activation method, characterized in that: The following steps are involved: The wastewater containing organic pollutants is heated, hydrogen peroxide is added, the pH is adjusted, and then a pre-oxidized iron-based amorphous alloy is added and reacted under stirring to degrade the organic pollutants; The iron-based amorphous alloy is subjected to high-temperature oxidation treatment in air or an atmosphere with an oxygen partial pressure of not less than 0.01 MPa to obtain the pre-oxidized iron-based amorphous alloy.

2. The method for treating organic pollutants in wastewater by using a pre-oxidation activation method to strengthen an iron-based amorphous alloy according to claim 1, characterized in that: The concentration of the organic pollutants in the wastewater is 5-350 mg / L, the amount of hydrogen peroxide added is 1-30 mmol / L, and the amount of pre-oxidized iron-based amorphous alloy added is 0.05-20 g / L.

3. The method for treating organic pollutants in wastewater by using a pre-oxidation activation method to strengthen an iron-based amorphous alloy according to claim 1, characterized in that: The temperature of the high-temperature oxidation is 450-850° C., and the time is 6 seconds to 30 minutes.

4. The method for treating organic pollutants in wastewater by using a pre-oxidation activation method to strengthen an iron-based amorphous alloy according to claim 3, characterized in that: The temperature of the high-temperature oxidation is 500-800°C.

5. The method for treating organic pollutants in wastewater by using a pre-oxidation activation method to strengthen an iron-based amorphous alloy according to claim 4, characterized in that: The temperature of the high temperature oxidation is 650-750°C.

6. The method for treating organic pollutants in wastewater by using a pre-oxidation activation method to strengthen an iron-based amorphous alloy according to claim 1, characterized in that: The iron-based amorphous alloy includes one or more of newly prepared amorphous strips by casting or melting, strips with partially aged and crystallized surfaces, and waste strips with rusted and oxidized surfaces. The iron-based amorphous alloy includes silicon, boron and iron, wherein the mass percentage of iron atoms is ≥50%.

7. The method for treating organic pollutants in wastewater by using a pre-oxidation activation method to strengthen an iron-based amorphous alloy according to claim 1, characterized in that: The heating temperature is 10-80° C., the pH is 2.0-6.5, and the stirring time is 10 s-30 min.

8. The method for treating organic pollutants in wastewater by using a pre-oxidation activation method to strengthen an iron-based amorphous alloy according to claim 1, characterized in that: The organic pollutants include one or more of Orange II, methylene blue, rhodamine B and phenol.

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