Pollutant degradation method based on triboelectricity and application

Abstract

The invention discloses a pollutant degradation method based on triboelectricity and application, and the method comprises the following steps: providing a sewage treatment substance which can rub with water molecules in an ultrasonic treatment process under an aerobic condition in sewage to generate a triboelectricity effect, so that the water molecules are oxidized based on the triboelectricity effect to generate hydroxyl free radicals, and the hydroxyl free radicals are used for degrading pollutants; the sewage treatment substances do not chemically react with pollutants in the sewage; adding the sewage treatment substance into to-be-treated sewage under an aerobic condition, uniformly stirring, and waiting for ultrasonic treatment under a room temperature condition; the method comprises the following steps: performing ultrasonic treatment on to-be-treated sewage, so that a sewage treatment object rubs with water molecules in the to-be-treated sewage to generate a triboelectric effect, and the water molecules in the to-be-treated sewage are oxidized based on the triboelectric effect to generate hydroxyl radicals. The method is simple in reaction condition and wide in application range, and compared with a conventional sewage treatment technology for degrading pollutants, the method is greener, simpler and cheaper.

Description

Technical Field

[0001] The invention relates to the technical field of environmental engineering, and in particular to a method for resisting triboelectric-based pollutant degradation and application thereof. Background Art

[0002] The rapid development of industrialization and urbanization, coupled with the growing world population, has led to a sharp increase in global water pollution. Synthetic dyes are produced in large quantities due to their wide application in many industries such as textiles, cosmetics, clothing, food, papermaking, rubber, printing and plastics, and the resulting environmental pollution problems are becoming increasingly prominent. The large-scale discharge of these dyes has become one of the main sources of environmental pollution, posing a serious threat to ecosystems and human health. Due to their stability and resistance to biodegradation, they can have an adverse effect on the transparency and aesthetics of water bodies. This will inhibit the penetration of sunlight, hinder the photosynthesis of aquatic plants, increase the biological oxygen demand (BOD) and chemical oxygen demand (COD), and harm the ecosystem. In addition, the consumption of these dyes by aquatic animals may cause physiological disorders, which can be transmitted through the food chain and cause kidney, brain, liver, nervous and reproductive system dysfunction in animals and humans. Traditional treatment technologies have many disadvantages, including low efficiency at lower concentrations, the generation of secondary wastes that require additional treatment, the inability to cause degradation due to the complex organic structure of the dyes, and high regeneration costs. Advanced oxidation process (AOP) can remove, inactivate or convert harmful and toxic organic and inorganic pollutants in water and wastewater into secondary by-products with lower toxicity than the parent molecules. It is a new technology based on the reform of classical chemical oxidation method in traditional water treatment technology. Its essence is the chemical reaction of utilizing hydroxyl radicals to oxidize and degrade various pollutants in the water phase.

[0003] Hydroxyl radicals are the most potent reactive oxygen species (ROS) present in the environment. Hydroxyl radicals generated in the atmosphere, surface waters, and oceans have a significant impact on the fate of redox-active species, including nutrient compounds and pollutants. Hydroxyl radicals consist of one hydrogen atom and one oxygen atom, which makes them highly reactive and can easily steal hydrogen atoms from other molecules to form water molecules. The radical reactivity of hydroxyl radicals with various water pollutants, including bacteria, organic compounds, and inorganic compounds, remains a subject of interest for science and regulatory agencies in pollution prevention in wastewater treatment processes. Currently, the generation of free radicals in advanced oxidation processes mainly relies on Fenton (wastewater treatment technology) and Fenton-like technologies. However, Fenton and Fenton-like technologies have several shortcomings: 1. They are very sensitive to pH, and the optimal reaction pH is usually between 2.5-3. Outside this range, the reaction efficiency will be significantly reduced, especially under alkaline conditions; 2. During the reaction, Fe2+ may react with H2O2 to form insoluble iron hydroxide precipitates, which greatly reduces the efficiency of hydrogen peroxide. 3. The Fenton method requires the addition of a large amount of H2O2, which not only increases the processing cost, but also has unstable chemical properties and potential safety hazards in storage, processing and transportation. Therefore, finding a green, safe, simple and cheap method for producing hydroxyl radicals has important practical significance for environmental governance. Summary of the invention

[0004] In order to solve the technical problems in the prior art, the present invention provides a triboelectric pollutant degradation method and application, which can achieve green, safe, simple and cheap hydroxyl radical production to degrade pollutants in sewage.

[0005] Specifically, the present invention includes the following contents.

[0006] In a first aspect of the present invention, a triboelectric pollutant degradation method is provided, which comprises the following steps:

[0007] Step S1, providing a sewage treatment product, wherein the sewage treatment product can rub against water molecules in the sewage to generate a triboelectric effect during ultrasonic treatment under aerobic conditions in the sewage, so that the water molecules in the sewage are oxidized based on the triboelectric effect to generate hydroxyl radicals, and the sewage treatment product does not chemically react with pollutants in the sewage; Step S2, adding the sewage treatment product to the sewage to be treated under aerobic conditions and stirring evenly, waiting for ultrasonic treatment under room temperature; Step S3, performing ultrasonic treatment on the sewage to be treated, so that the sewage treatment product and the water molecules in the sewage to be treated rub against each other to generate a triboelectric effect, so that the water molecules in the sewage to be treated are oxidized based on the triboelectric effect to generate hydroxyl radicals.

[0008] Optionally, the sewage treatment product is one of tinfoil fragments, aluminum particles, polytetrafluoroethylene particles and fluorinated ethylene propylene copolymer particles, and the tinfoil fragments are fragments obtained by mechanically cutting tinfoil.

[0009] Optionally, the expanded surface area of ​​the tinfoil fragments is 0.25-1 cm 2 .

[0010] Optionally, the mass concentration of any one of the tinfoil fragments, the aluminum particles, the polytetrafluoroethylene particles and the fluorinated ethylene-propylene copolymer particles in the wastewater to be treated is 0.15-0.5 mg / mL.

[0011] Optionally, the ultrasonic treatment of the wastewater to be treated is performed for 1.5-3 hours under oxygen conditions.

[0012] Optionally, the ultrasonic frequency of the ultrasonic treatment is 30-50 KHz.

[0013] Optionally, the wastewater to be treated is dye wastewater.

[0014] Optionally, the dye in the dye wastewater is methyl orange and / or safranin T.

[0015] Optionally, the aerobic condition is a gas environment under natural conditions.

[0016] The second aspect of the present invention provides an application of the triboelectric-based pollutant degradation method according to any one of the above items in the field of pollutant degradation in sewage.

[0017] The technical effects of the present invention include but are not limited to:

[0018] The present invention can be used for the degradation of dyes in sewage. Tin foil fragments (or any one of aluminum particles, polytetrafluoroethylene particles and fluorinated ethylene propylene copolymer particles) are added into the dye sewage. Under the action of ultrasound, the tin foil fragments (or any one of aluminum particles, polytetrafluoroethylene particles and fluorinated ethylene propylene copolymer particles) react with water molecules based on the triboelectric effect to generate hydroxyl radicals with high oxidation performance. The hydroxyl radicals react with the dyes in the sewage to generate an oxidation reaction, thereby degrading the dyes in the sewage and achieving the effect of purifying the water quality.

[0019] Compared with the prior art methods for generating hydroxyl radicals, the present invention has the following advantages: (1) the present invention can be carried out in a natural aerobic and room temperature environment, the reaction conditions are simple, and the scope of application is wide; (2) compared with the (quasi) Fenton method for generating H2O2 to degrade pollutants, the present invention utilizes hydroxyl radicals generated by oxidation of water molecules to degrade pollutants, which is greener, safer, simpler and cheaper, and can be promoted and used on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 Schematic diagram of the experimental device in the embodiment of the present invention.

[0022] Figure 2 FIG. 5 is a graph showing the change of the fluorescence intensity of hydroxyl radicals over time in an embodiment of the present invention.

[0023] Figure 3 The figure shows the change of methyl orange concentration over time in the example of the present invention.

[0024] Figure 4 The figure shows the change of concentration of Safranin T over time in the example of the present invention. DETAILED DESCRIPTION

[0025] 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 should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0026] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that the upper and lower limits of the scope and each intermediate value therebetween are specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0027] Unless otherwise specified, all technical and scientific terms used herein have the same meanings 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 related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail. Unless otherwise specified, "%" is a percentage based on weight.

[0028] Those skilled in the art should understand that other steps or operations may be included before or after the steps of this embodiment, or between any steps, for example, to further optimize and / or improve the method described in the present invention.

[0029] Example 1

[0030] Hydroxyl radical detection: Heat 100 mL of ultrapure water, add an appropriate amount of NaOH powder to it, prepare a 2 mM NaOH solution, and then add terephthalic acid to it to make a final concentration of 0.5 mM. Using the prepared 0.5 mM terephthalic acid solution, add 0.25 g of tin foil fragments (1×1 cm), place it in a 40 KHz ultrasonic instrument for ultrasonication, and take samples at irregular intervals. Since 2-hydroxyterephthalic acid generated by the reaction of terephthalic acid and hydroxyl radicals has special fluorescence at λex=320 nm and λem=425 nm, the generation of hydroxyl radicals can be monitored by measuring the fluorescence intensity with a fluorescence spectrophotometer. The higher the concentration of hydroxyl radicals, the stronger the fluorescence intensity.

[0031] Example 2

[0032] Methyl orange degradation test: add 0.5 mg of methyl orange to 100 mL of aqueous solution, dissolve it, add 0.25 g of tin foil fragments (0.5×0.5 cm), or add 0.25 g of any one of aluminum particles, polytetrafluoroethylene particles and fluorinated ethylene propylene copolymer particles, place it in a 45KHz ultrasonic instrument for ultrasonication, take samples at irregular intervals, and use a UV-visible spectrophotometer to monitor the degradation of methyl orange in the aqueous solution (detection wavelength 465 nm). Among them, methyl orange is a chemical dye, and its aqueous solution is yellow. It is formed by coupling p-aminobenzenesulfonic acid with N,N-dimethylaniline after diazotization. The molecular structure of methyl orange is an aromatic azo compound with two benzene rings connected by an azo group, and one of the benzene rings is linked to a -SO3Na group. Its chromophore is a conjugated system composed of an azo bond and a benzene ring, and dimethylamino (CH3)2N— is a color-enhancing group. When exposed to gamma ray radiation, the dimethylamino (CH3)2N- in the molecular structure of methyl orange is destroyed, and the conjugated system composed of azo bond and benzene ring is destroyed, and its characteristic absorption peak gradually weakens or even disappears. The stronger the gamma ray radiation intensity, the more methyl orange is destroyed, the more serious the degree of destruction, and the greater the change in absorbance value.

[0033] Example 3

[0034] Safranine T degradation test: add 0.35 mg of Safranine T to 100 mL of aqueous solution, dissolve it, add 0.25 g of tin foil fragments (0.25×0.25 cm), or add 0.25 g of any one of aluminum particles, polytetrafluoroethylene particles and fluorinated ethylene propylene copolymer particles, place it in a 35KHz ultrasonic instrument for ultrasonication, and take samples at irregular intervals, and use a UV-visible spectrophotometer to monitor the degradation of Safranine T in the aqueous solution (detection wavelength 530 nm). Safranine T is a chemical substance with a molecular formula of C 20 H 19 Cl N4, Safflower T is a reddish brown powder, easily soluble in water to form a red solution, soluble in ethanol to form a red solution with yellow fluorescence, mainly used as a redox indicator.

[0035] in, Figure 1 A diagram of a triboelectric-based pollutant degradation device is shown, reflecting the entire process and reaction mechanism of triboelectric-based pollutant degradation in sewage.

[0036] Among them, Figure 2 It can be seen that under aerobic conditions and ultrasonic treatment conditions, a large number of hydroxyl radicals are generated during the contact and friction between tinfoil fragments (or any one of aluminum particles, polytetrafluoroethylene particles and fluorinated ethylene propylene copolymer particles) and water molecules, indicating that the tinfoil fragments and the water molecules in the sewage produce a triboelectric effect under ultrasonic conditions. In this process, the water molecules are oxidized to produce hydroxyl radicals that can be used to degrade pollutants.

[0037] Among them, Figure 3 It can be seen that under aerobic conditions and ultrasonic treatment conditions, the triboelectric effect generated by the friction between tinfoil fragments (or any of aluminum particles, polytetrafluoroethylene particles and fluorinated ethylene propylene copolymer particles) and water molecules in the sewage not only produces hydroxyl radicals, but also degrades methyl orange.

[0038] Among them, Figure 4 It can be seen that under aerobic conditions and ultrasonic treatment conditions, the triboelectric effect generated by the friction between tinfoil fragments (or any of the aluminum particles, polytetrafluoroethylene particles and fluorinated ethylene propylene copolymer particles) and water molecules in the sewage not only produces hydroxyl radicals, but also degrades Safranin T.

[0039] In summary, the present invention is based on the triboelectric effect. By adding an appropriate amount of tinfoil fragments (or any one of aluminum particles, polytetrafluoroethylene particles and fluorinated ethylene propylene copolymer particles) into the dye wastewater, the tinfoil fragments (or any one of aluminum particles, polytetrafluoroethylene particles and fluorinated ethylene propylene copolymer particles) contact and rub with water molecules in the wastewater under aerobic conditions and ultrasonic treatment, thereby generating hydroxyl radicals with high oxidizing properties, which react with the dye in the wastewater to oxidize and degrade the dye.

[0040] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. Various adjustments or changes may be made to the exemplary embodiments of the present specification without departing from the scope or spirit of the present invention. The scope of the claims should be based on the broadest interpretation to cover all modifications and equivalent structures and functions.

Claims

1. A triboelectric pollutant degradation method, characterized in that: The following steps are involved: Step S1, providing a sewage treatment product, wherein the sewage treatment product can rub against water molecules in the sewage during ultrasonic treatment under aerobic conditions to generate a triboelectric effect, so that the water molecules in the sewage are oxidized based on the triboelectric effect to generate hydroxyl radicals, and the sewage treatment product does not chemically react with pollutants in the sewage; Step S2, adding the sewage treatment product to the sewage to be treated under aerobic conditions and stirring evenly, and waiting for ultrasonic treatment under room temperature; Step S3, ultrasonically treating the sewage to be treated, so that the sewage treated material and water molecules in the sewage to be treated rub against each other to generate a triboelectric effect, so that the water molecules in the sewage to be treated are oxidized based on the triboelectric effect to generate hydroxyl radicals.

2. The triboelectric pollutant degradation method according to claim 1, characterized in that: The sewage treatment product is one of tinfoil fragments, aluminum particles, polytetrafluoroethylene particles and fluorinated ethylene propylene copolymer particles, and the tinfoil fragments are fragments obtained by mechanically cutting tinfoil.

3. The triboelectric pollutant degradation method according to claim 2, characterized in that: The expanded surface area of ​​the tinfoil fragments is 0.25-1 cm 2 .

4. The triboelectric pollutant degradation method according to claim 2, characterized in that: The mass concentration of any one of the tin foil fragments, the aluminum particles, the polytetrafluoroethylene particles and the fluorinated ethylene-propylene copolymer particles in the wastewater to be treated is 0.15-0.5 mg / mL.

5. The triboelectric pollutant degradation method according to claim 1, characterized in that: The ultrasonic treatment of the wastewater to be treated under oxygen conditions lasts for 1.5-3 hours.

6. The triboelectric pollutant degradation method according to claim 1, characterized in that: The ultrasonic frequency of the ultrasonic treatment is 30-50 KHz.

7. The triboelectric pollutant degradation method according to claim 1, characterized in that: The wastewater to be treated is dye wastewater.

8. The triboelectric pollutant degradation method according to claim 7, characterized in that: The dye in the dye wastewater is methyl orange and / or safranin T.

9. The triboelectric pollutant degradation method according to claim 1, characterized in that: The aerobic condition is a gas environment under natural conditions.

10. Application of the triboelectric pollutant degradation method according to any one of claims 1 to 9 in the field of pollutant degradation in sewage.

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