A method for the degradation of bisphenol A by tea residue and iron filings in conjunction with the activation of persulfate

Abstract

This invention provides a method for the degradation of bisphenol A (BPA) by persulfate activated by tea residue and iron filings. The method includes: freeze-drying and pulverizing tea residue to obtain coarse tea residue powder; sieving the coarse tea residue powder to obtain tea residue powder; mixing the tea residue powder with iron-containing substances to obtain an iron-containing tea residue mixture; adding the iron-containing tea residue mixture to a solution containing persulfate and BPA to initiate a chemical reaction; and measuring the BPA content to obtain the measurement results. This invention utilizes tea residue to replace pure tea polyphenols, constructing a persulfate degradation system activated by tea residue and iron filings, achieving a high-efficiency removal of 93.7% of BPA. This not only maintains the complexation and reduction advantages of tea polyphenols but also realizes the resource utilization of waste. It provides a low-cost, green, and sustainable technical path for BPA pollution control, with significant environmental and economic benefits.

Description

Technical Field

[0001] This invention relates to the fields of environmental science and engineering technology, and in particular to a method for the degradation of bisphenol A by persulfate activated by tea residue and iron filings. 11. Background Technology Bisphenol A (BPA), a typical endocrine disruptor, is widely found in water, soil, and plastic products. Due to its persistence, bioaccumulation, and toxicity, it poses a significant threat to ecosystems and human health. BPA can mimic or inhibit the effects of hormones in organisms, causing reproductive toxicity, carcinogenicity, and other harms. Traditional water treatment technologies, such as physical adsorption or biodegradation, are inefficient and prone to secondary pollution, making it difficult to effectively remove these recalcitrant pollutants. Therefore, developing efficient, low-cost, and environmentally friendly BPA degradation technologies has become a current research hotspot. Persulfate advanced oxidation technology, through the activation of persulfate to generate sulfate radicals (SO4· ... - Active species such as iron filings can rapidly mineralize pollutants and are considered an effective means of treating organic pollutants. Iron-based materials (such as iron filings) have the advantages of low cost and wide availability as heterogeneous catalysts for activating persulfate, but they have significant drawbacks in practical applications: Fe... 2+ The reaction with persulfate is rapid and irreversible, resulting in a short oxidation duration; iron filings readily form ferric hydroxide precipitate during the reaction, limiting the applicable pH range (usually requiring acidic conditions); and homogeneous iron activation systems carry the risk of residual metal ions. These limitations restrict the large-scale application of iron-activated persulfate technology. To address these issues, researchers have introduced complexing reducing agents (such as ethylenediaminetetraacetic acid and hydroxylamine) to promote the oxidation of Fe. 2+ / Fe 3+ While the chemicals can be recycled, some are toxic or difficult to degrade, potentially causing secondary pollution.

[0003] 12. In recent years, natural polyphenols have attracted attention as environmentally friendly complexing and reducing agents. Tea polyphenols are the main active components in tea, including catechins (such as epigallocatechin gallate, EGCG) and phenolic acids (such as gallic acid, GA). Their abundant phenolic hydroxyl structures can react with Fe through complexation-reduction reactions. 3+ A stable complex is formed and reduced to Fe. 2+ This continuously activates persulfate and enhances the activity of free radicals (such as SO4·). - , HO·) and non-free radicals (such as 1 Degradation efficiency via the O2 pathway. Tea residue, as a waste product after tea processing or consumption, is rich in tea polyphenols and can replace pure EGCG or GA for synergistic activation of persulfate by iron filings.

[0004] 13. This invention aims to solve the problems of high cost of chemical reagents, resource waste, and secondary pollution in existing technologies. By utilizing tea dregs, an agricultural waste, to replace pure tea polyphenols, a synergistic degradation system of "tea dregs-iron filings-persulfate" is constructed. This technology not only continues the complexation and reduction advantages of tea polyphenols but also realizes the resource utilization of waste: tea dregs are solid waste after tea consumption, and their direct utilization can reduce treatment costs; iron filings, as industrial waste, also conform to the concept of a circular economy. 14. Summary of the Invention

[0006] To overcome the problems existing in related technologies, the purpose of this invention is to provide a method for the degradation of bisphenol A by tea residue and iron filings in conjunction with persulfate activation. This method utilizes tea residue, an agricultural waste, to replace pure tea polyphenols and constructs a "tea residue-iron filings-persulfate" synergistic degradation system to achieve efficient removal of bisphenol A.

[0007] 15. A method for the degradation of bisphenol A by persulfate activated by tea residue and iron filings, comprising: Tea leaves are freeze-dried and pulverized to obtain coarse tea leaves powder; the coarse tea leaves powder is then sieved to obtain fine tea leaves powder. The tea residue powder and iron-containing substances are mixed to obtain an iron-containing tea residue mixture; The iron-containing tea residue mixture was added to a solution containing persulfate and bisphenol A to initiate a chemical reaction; the bisphenol A was measured to obtain the measurement results.

[0008] 16. In a preferred embodiment of the present invention, the step of mixing the tea residue powder and the iron-containing substance to obtain an iron-containing tea residue mixture comprises: The tea residue powder and the iron-containing substance are mixed in a certain proportion; wherein the mass ratio of the tea residue powder to the iron-containing substance is 1:4.

[0009] 17. In a preferred embodiment of the present invention, the iron-containing substance is iron filings, and the iron filings include ferric oxide.

[0010] 18. In a preferred embodiment of the present invention, the step of adding the iron-containing tea residue mixture to a solution containing persulfate and bisphenol A to initiate a chemical reaction includes: Bisphenol A solution, ultrapure water, and persulfate were added to an Erlenmeyer flask to obtain a reaction solution; wherein the volume of the bisphenol A solution was 50 ml, and the concentration of the bisphenol A solution was 10 mg·L⁻¹. -1 The concentration of the persulfate is 100 mmol·L⁻¹. -1 The concentration of persulfate in the reaction solution is 300 µmol·L⁻¹. -1 ; The iron-containing tea residue mixture is added to the reaction solution to allow the iron-containing tea residue mixture to undergo a chemical reaction in the reaction solution; wherein the mass of the iron-containing tea residue mixture is 6.25 mg.

[0011] 19. In a preferred embodiment of the present invention, the step of measuring the bisphenol A to obtain the measurement result includes: At set time points, the reaction solution is pipetted into a centrifuge tube containing sodium thiosulfate for vortex mixing to obtain a mixture; wherein, the set time points include 0, 10, 20, 30, 40, 50, and 60 min after the chemical reaction is started; The mixture is filtered using a filter to obtain a filtrate; The filtrate was measured using high performance liquid chromatography (HPLC) to obtain the measurement results.

[0012] 20. In a preferred embodiment of the present invention, the step of sieving the coarse tea residue powder to obtain tea residue powder comprises: The coarse powder of tea residue is sieved using a sieve to obtain coarse powder that does not pass through the sieve and fine powder that passes through the sieve; the size range of the sieve is greater than or equal to 40 mesh and less than or equal to 100 mesh. Collect the sieved fine powder to obtain tea residue powder.

[0013] 21. In a preferred embodiment of the present invention, the tea is green tea, oolong tea, yellow tea, black tea, white tea, or dark tea.

[0014] 22. In a preferred embodiment of the present invention, the content of ferric oxide in the iron filings is 97%.

[0015] 23. In a preferred embodiment of the present invention, the persulfate is potassium persulfate or sodium persulfate.

[0016] 24. The beneficial effects of the present invention are as follows: The method for degrading bisphenol A (BPA) by activating persulfate with iron filings using tea residue as a co-process, provided by this invention, includes: freeze-drying and pulverizing the tea residue to obtain coarse tea residue powder; sieving the coarse tea residue powder to obtain tea residue powder; mixing the tea residue powder with iron-containing substances to obtain an iron-containing tea residue mixture; adding the iron-containing tea residue mixture to a solution containing persulfate and BPA to initiate a chemical reaction; and measuring the BPA to obtain the measurement results. The tea residue powder and iron-containing substances are mixed in a certain proportion to obtain the iron-containing tea residue mixture. Adding the iron-containing tea residue mixture to a solution containing persulfate and BPA initiates a chemical reaction. First, the iron-containing substances react with the persulfate, generating sulfate free radicals after activation, which are used to degrade BPA. During the activation reaction, the Fe2+ in the iron-containing substances is released. 2+ Oxidized to Fe 3+ Then, by utilizing the reducing effect of tea polyphenols in the tea dregs, the iron-containing substances (Fe) can be re-reduced. 3+ Reduced to Fe 2+ This invention utilizes tea residue waste, in synergy with iron-containing substances, to achieve the degradation of bisphenol A, thus enabling the activation reaction to continue. Iron oxides generated from the corrosion of the iron-containing surface combine with tea polyphenol molecules through coordination bonds or hydrogen bonds, forming an interfacial structure with sustained catalytic activity. The persulfate activation system based on the synergistic effect of tea polyphenols and iron-containing substances not only exhibits excellent reusability but also strong adaptability to common environmental pollutants, providing a theoretical basis and technical support for large-scale application. 25. Attached Figure Description

[0018] Figure 1 This is a flowchart of the method for activating persulfate degradation of bisphenol A with tea residue and iron filings according to the present invention; Figure 2 This is a graph showing the degradation rate of bisphenol A under different conditions of tea residue and iron filings according to the present invention. Figure 3 This is a graph showing the degradation rate constants and degradation rates of bisphenol A by different tea leaves according to the present invention. Figure 4 This is a comparison diagram of the degradation effects of green tea and GA on bisphenol A according to the present invention; Figure 5 This is a graph showing the degradation rate of bisphenol A by the iron filings after three cycles of use according to the present invention. 26. Detailed Implementation Preferred embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0020] 27. Example 1 like Figures 1 to 5 As shown in this embodiment, a method for the degradation of bisphenol A by persulfate activated by tea residue and iron filings is provided, comprising: S1: Freeze-dry and pulverize the tea leaves to obtain coarse tea leaves powder; sieve the coarse tea leaves powder to obtain fine tea leaves powder. S2: Mix the tea residue powder and iron-containing substances to obtain an iron-containing tea residue mixture; S3: Add the iron-containing tea residue mixture to a solution containing persulfate and bisphenol A to initiate a chemical reaction; measure the bisphenol A and obtain the measurement result.

[0021] 28. The step of mixing the tea residue powder with iron-containing substances to obtain an iron-containing tea residue mixture comprises: The tea residue powder and the iron-containing substance are mixed in a certain proportion; wherein the mass ratio of the tea residue powder to the iron-containing substance is 1:4.

[0022] 29. The iron-containing substance is iron filings, the iron filings are composed of ferric oxide, and the ferric oxide content in the iron filings is 97%.

[0023] 30. Iron-containing materials include elemental iron, iron compounds, natural minerals, composite and loaded iron-based materials, and iron-containing waste, among which elemental iron includes zero-valent iron, such as iron filings, iron powder, iron shavings, and scrap iron, which continuously provide Fe through in-situ corrosion. 2+ Iron is one of the most direct activators. Iron compounds include ferrous salts, ferric salts, and iron oxides, etc. Ferrous salts can directly provide Fe. 2+ It has high activation efficiency and rapid reaction; ferric salts and iron oxides need to be reduced to Fe in the system. 2+ Only then can it be efficiently activated. Natural minerals include magnetite, hematite, etc., among which magnetite also contains Fe. 2+ and Fe 3+ Iron is an excellent natural activator. Composite and supported iron-based materials, including carbon-based supported iron and porous materials supported iron, have the advantages of good stability and strong synergistic effect. Iron-containing wastes, such as steel slag and iron tailings, have the advantage of extremely low cost and can achieve waste-to-waste treatment.

[0024] 31. In this embodiment, taking iron filings as an example, after processing tea leaves according to steps S1 and S2, tea residue powder is obtained. The tea residue powder and iron-containing substances are mixed in a certain proportion, wherein the mass ratio of tea residue powder to iron-containing substances is 1:1 to 1:4, to obtain an iron-containing tea residue mixture. For example, mixing tea residue powder and iron-containing substances in a mass ratio of 1:1 means that 1 mg of tea residue powder and 1 mg of iron-containing substances can be mixed to obtain a 2 mg iron-containing tea residue mixture. In this embodiment, tea residue powder and iron filings are mixed in a mass ratio of 1:4. For example, if the mass of tea residue powder is 1 mg and the mass of iron filings is 4 mg, mixing 1 mg of tea residue powder and 4 mg of iron filings will yield a 5 mg iron-containing tea residue mixture.

[0025] 32. The components of iron filings include ferric oxide (Fe₂O₃) and impurities. Fe₂O₃ accounts for 97% of the composition and is the most common oxidation product on the surface of iron filings. It is also a key component affecting the reactivity of the persulfate activation system based on the synergistic effect of tea residue and iron filings. During the activation reaction, iron filings undergo an activation reaction with persulfate, converting the Fe₂O₃ in the iron filings into Fe₂O₃. 2+ Oxidized to Fe 3+ Because tea dregs powder is rich in tea polyphenols, under the action of tea polyphenols, the Fe in the iron filings... 3+ Reducing to Fe 2+ This allows the activation reaction to continue, thereby continuously activating persulfate and enhancing the free radical (such as SO4·) activity. - , HO·) and non-free radicals (such as 1 The O2 pathway's effect on the degradation of bisphenol A. The impurity content in the iron filings is 3%, including metallic elements such as carbon (C), manganese (Mn), and silicon (Si), as well as non-metallic elements such as surface oxides, coatings or contaminants, processing byproducts, and physical mixtures.

[0026] 33. Step S2 includes steps S21 and S22.

[0027] 34.S21: Freeze-dry and pulverize the brewed tea leaves to obtain coarse tea leaf powder; S22: The coarse tea residue powder is sieved to obtain tea residue powder.

[0028] 35. The step of sieving the coarse tea residue powder to obtain tea residue powder comprises: S221: The coarse powder of tea residue is sieved using a sieve to obtain coarse powder that does not pass through the sieve and fine powder that passes through the sieve; the size range of the sieve is greater than or equal to 40 mesh and less than or equal to 100 mesh. S222: Collect the sieved fine powder to obtain tea residue powder.

[0029] 36. The sizes of the sieves include 40 mesh, 50 mesh, 60 mesh, 70 mesh, 80 mesh, 90 mesh and 100 mesh. The 40 mesh sieve has an aperture of 0.425 mm and can be used to screen particles with a diameter of less than or equal to 0.425 mm. The 100 mesh sieve has an aperture of 0.15 mm and can be used to screen particles with a diameter of less than or equal to 0.15 mm.

[0030] 37. The method of steeping tea leaves in warm water to obtain steeped tea residue includes: S11: Brew the tea leaves with warm water for the first time to obtain the tea leaves after the first brewing. S12: The tea leaves from the first brewing are brewed a second time with warm water to obtain tea leaves from the second brewing. S13: The tea leaves that have been brewed twice are brewed a third time with warm water to obtain brewed tea leaves.

[0031] 38. In this embodiment, a 40-mesh sieve is used as an example. First, the tea leaves are brewed with warm water, and this process is repeated three times. The solid tea leaves after brewing are collected to obtain brewed tea leaves. Next, the brewed tea leaves are freeze-dried and then pulverized to obtain coarse tea leaf powder. The coarse tea leaf powder is then sieved through a 40-mesh sieve. Particles larger than the sieve aperture (0.425 mm) remain at the top of the sieve, while particles smaller than or equal to the sieve aperture (0.425 mm) pass through the sieve. This results in coarse powder that does not pass through the sieve and fine powder that passes through. The fine powder that passes through the sieve is collected to obtain tea leaf powder.

[0032] 39. The method for activating persulfate degradation of bisphenol A using tea residue and iron filings provided in this embodiment includes: brewing tea leaves with warm water to obtain brewed tea residue; freeze-drying and pulverizing the brewed tea residue to obtain coarse tea residue powder; sieving the coarse tea residue powder to obtain tea residue powder; mixing the tea residue powder with iron-containing substances to obtain an iron-containing tea residue mixture; adding the iron-containing tea residue mixture to a solution containing persulfate and bisphenol A to initiate a chemical reaction and obtain reactants; measuring the reactants and obtaining measurement results. After repeatedly brewing tea leaves with warm water three times, the remaining solid tea residue is collected to obtain brewed tea residue. The brewed tea residue is then freeze-dried, pulverized, and sieved to obtain a uniformly sized powder, thus obtaining tea residue powder. The tea residue powder and iron-containing substances are mixed in a certain proportion to obtain an iron-containing tea residue mixture. When a mixture of iron-containing tea leaves is added to a solution containing persulfate and bisphenol A, a chemical reaction begins. First, the iron-containing substances undergo an activation reaction with the persulfate. After activation, the persulfate generates sulfate free radicals, which degrade bisphenol A. During this activation reaction, the iron-containing substances release their Fe... 2+ Oxidized to Fe3+ Then, by utilizing the reducing effect of tea polyphenols in the tea dregs, the iron-containing substances (Fe) can be re-reduced. 3+ Reduced to Fe 2+ This invention utilizes tea residue waste, in synergy with iron-containing substances, to achieve the degradation of bisphenol A, thus enabling the activation reaction to continue. Iron oxides generated from the corrosion of the iron-containing surface combine with tea polyphenol molecules through coordination bonds or hydrogen bonds, forming an interfacial structure with sustained catalytic activity. The persulfate activation system based on the synergistic effect of tea polyphenols and iron-containing substances not only exhibits excellent reusability but also strong adaptability to common environmental pollutants, providing a theoretical basis and technical support for large-scale application.

[0033] 40. Example 2 like Figures 1 to 5 As shown, this embodiment provides a method for the degradation of bisphenol A by persulfate activated by tea residue and iron filings. This embodiment describes the differences between it and Example 1, and the method includes: S1: Brew the tea leaves with warm water to obtain the tea leaves after brewing; S2: Freeze-dry and pulverize the brewed tea leaves to obtain coarse tea leaves powder; sieve the coarse tea leaves powder to obtain fine tea leaves powder. S3: Mix the tea residue powder and iron-containing substances to obtain an iron-containing tea residue mixture; S4: Add the iron-containing tea residue mixture to a solution containing persulfate and bisphenol A to initiate a chemical reaction and obtain reactants; measure the reactants and obtain measurement results.

[0034] 41. Step S4 includes steps S41 and S42.

[0035] 42.S41: The iron-containing tea residue mixture is added to a solution containing persulfate and bisphenol A to initiate a chemical reaction and obtain the reactants; S42: Measure the reactants to obtain the measurement results.

[0036] 43. The addition of the iron-containing tea residue mixture to a solution containing persulfate and bisphenol A to initiate a chemical reaction and obtain reactants includes: S411: Add bisphenol A solution, ultrapure water, and persulfate to an Erlenmeyer flask to obtain a reaction solution; wherein the volume of the bisphenol A solution is 50 ml, and the concentration of the bisphenol A solution is 10 mg·L⁻¹. -1 The concentration of the persulfate is 100 mmol·L⁻¹. -1 The concentration of persulfate in the reaction solution is 300 µmol·L⁻¹.-1 ; S412: Add the iron-containing tea residue mixture to the reaction solution, so that the iron-containing tea residue mixture undergoes a chemical reaction in the reaction solution to obtain a reactant; wherein the mass of the iron-containing tea residue mixture is 6.25 mg.

[0037] 44. The measurement of the reactants to obtain measurement results includes: S421: At the set time points, the reaction solution is taken by pipette into a centrifuge tube containing sodium thiosulfate for vortex mixing to obtain a mixture; wherein, the set time points include 0, 10, 20, 30, 40, 50, and 60 min after the chemical reaction is started; S422: The mixture is filtered using a filter to obtain a filtrate; S423: The filtrate is measured using high performance liquid chromatography to obtain the measurement results.

[0038] 45. The tea mentioned is green tea, oolong tea, yellow tea, black tea, white tea, or dark tea. Green tea has the highest degree of fermentation, while dark tea has the lowest. Green tea has the highest content of tea polyphenols, while dark tea has the lowest content of tea polyphenols.

[0039] 46. ​​The persulfate mentioned is potassium peroxymonosulfate or sodium peroxymonosulfate. Bisphenol A (BPA) is an important chemical raw material widely used in the plastics industry, mainly for the production of polycarbonate plastics and epoxy resins. Persulfate (PMS) usually refers to potassium peroxymonosulfate (KHSO5) or sodium peroxymonosulfate (NaHSO5), which is a strong oxidizing agent. Persulfate (PMS) itself has limited oxidizing power and needs to be activated to generate strong oxidizing free radicals.

[0040] 47. In this embodiment, taking iron filings as an example, green tea, oolong tea, yellow tea, black tea, white tea, and dark tea are first brewed with warm water, and the tea leaves are kept. This process is repeated three times, and the tea leaves are collected to obtain brewed tea leaves. Next, the brewed tea leaves are freeze-dried and pulverized, then passed through a 40-mesh sieve to obtain tea leaf powder. Finally, the tea leaf powder and iron filings are mixed at a mass ratio of 1:4 to obtain an iron filings and tea leaf mixture.

[0041] 48. Add 50 mL of a 10 mg·L⁻¹ solution to each conical flask. -1 BPA solution, ultrapure water, and 100 mmol·L -1 A persulfate (PMS) stock solution was used to bring the initial concentration of PMS in the reaction solution to 300 µmol·L⁻¹. -1Then, 6.25 mg of a mixture of iron filings and tea residue was added to initiate the reaction. At the set time points (0, 10, 20, 30, 40, 50, and 60 min), 0.8 mL of sample was accurately pipetted into a container containing 0.2 mL of sodium thiosulfate (Na₂S₂O₃, 2.5 g·L⁻¹). -1 After vortexing the mixture in a centrifuge tube, the sample was filtered using a 0.22 µm aqueous polyether sulfone (PES) syringe filter, and the filtrate was transferred to a high-performance liquid chromatography-mass spectrometry sample vial for analysis.

[0042] 49. Fe in iron filings during the reaction process 2+ Oxidized to Fe 3+ By utilizing the reducing effect of tea polyphenols in tea leaves, Fe can be regenerated. 3+ Reduced to Fe 2+ This allows the reaction to continue. Sodium thiosulfate (Na2S2O3) can rapidly reduce residual permonosulfate (PMS) and quench reactive free radicals (such as SO4· ... - (or HO·), thereby terminating the reaction and preventing the reaction from continuing after sampling, which ensures the subsequent high-performance liquid chromatography (HPLC) measurement of BPA concentration.

[0043] 50. The following is a control experiment, in which gallic acid (GA) was replaced with tea leaves for testing. 50 mL of a 10 mg·L⁻¹ solution was added to each conical flask. -1 BPA solution, and reagents containing the main components of tea polyphenols such as gallic acid (GA), ultrapure water, and 100 mmol·L⁻¹ -1 A persulfate (PMS) stock solution was used to bring the initial concentration of PMS in the reaction solution to 300 µmol·L⁻¹. -1 The initial concentration of GA was 25 µmol·L⁻¹. -1 Then, 5 mg of iron filings were added to initiate the reaction (initial iron filings concentration: 100 mg·L⁻¹). At the set time points (0, 10, 20, 30, 40, 50, 60 min), 0.8 mL of sample was accurately pipetted into a container containing 0.2 mL of sodium thiosulfate (Na₂S₂O₃, 2.5 g·L⁻¹). -1 After vortexing the mixture in a centrifuge tube, the sample was filtered using a 0.22 µm aqueous polyether sulfone (PES) syringe filter, and the filtrate was transferred to a high-performance liquid chromatography-mass spectrometry sample vial for analysis.

[0044] 51. For example Figures 2 to 3As shown in the experimental results, there were significant differences in the degradation effect of tea residue on BPA among different types of tea. The degradation efficiency was as follows: green tea > oolong tea > yellow tea > black tea > white tea > dark tea, with corresponding degradation rates of 93.7%, 76.0%, 61.1%, 54.5%, 48.2%, and 34.5% within 60 min, respectively. Among them, green tea and oolong tea residue showed the best promoting effect. This result is highly consistent with the differences in tea polyphenol content among different types of tea. Green tea and oolong tea, due to their higher tea polyphenol content, can more effectively activate PMS and generate more reactive oxygen species (such as SO42-). •－ HO • and 1 O2), thereby significantly improving the degradation efficiency of BPA.

[0045] 52. For example Figure 4 and Figure 5 As shown, green tea leaf residue is significantly more effective than gallic acid (GA). After the reaction, the iron filings were filtered and recycled three times, and the Fe2O3 content of the iron filings decreased from 97% to 96%, without a significant weakening of the effect, indicating the advantage of reusability.

[0046] 53. This invention utilizes tea residue waste in synergy with iron filings to achieve the degradation of BPA. The specific mechanism is as follows: iron oxides produced by corrosion on the iron filings surface combine with tea polyphenol molecules through coordination bonds or hydrogen bonds, forming an interfacial structure with sustained catalytic activity. The persulfate activation system based on the synergistic effect of tea polyphenols and iron filings not only exhibits excellent reusability but also strong adaptability to common environmental pollutants, providing a theoretical basis and technical support for large-scale application.

[0047] 54. It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0048] 55. The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for the degradation of bisphenol A by persulfate activated by tea residue and iron filings, characterized in that, include: Tea leaves are freeze-dried and pulverized to obtain coarse tea leaves powder; the coarse tea leaves powder is then sieved to obtain fine tea leaves powder. The tea residue powder and iron-containing substances are mixed to obtain an iron-containing tea residue mixture; The iron-containing tea residue mixture was added to a solution containing persulfate and bisphenol A to initiate a chemical reaction; the bisphenol A was measured to obtain the measurement results.

2. The method for degrading bisphenol A by tea residue and iron filings in conjunction with persulfate activation according to claim 1, characterized in that, The process of mixing the tea residue powder with iron-containing substances to obtain an iron-containing tea residue mixture includes: The tea residue powder and the iron-containing substance are mixed in a certain proportion; wherein the mass ratio of the tea residue powder to the iron-containing substance is 1:

4.

3. The method for the degradation of bisphenol A by persulfate in conjunction with tea residue and iron filings according to claim 1, characterized in that, The iron-containing substance is iron filings, and the iron filings contain ferric oxide.

4. The method for degrading bisphenol A by tea residue and iron filings in conjunction with persulfate activation according to claim 1, characterized in that, The addition of the iron-containing tea residue mixture to a solution containing persulfate and bisphenol A to initiate a chemical reaction includes: Bisphenol A solution, ultrapure water, and persulfate were added to an Erlenmeyer flask to obtain a reaction solution; wherein the volume of the bisphenol A solution was 50 ml, and the concentration of the bisphenol A solution was 10 mg·L⁻¹. -1 The concentration of the persulfate is 100 mmol·L⁻¹. -1 The concentration of persulfate in the reaction solution is 300 µmol·L⁻¹. -1 ; The iron-containing tea residue mixture is added to the reaction solution to allow the iron-containing tea residue mixture to undergo a chemical reaction in the reaction solution; wherein the mass of the iron-containing tea residue mixture is 6.25 mg.

5. The method for degrading bisphenol A by tea residue and iron filings in conjunction with persulfate activation according to claim 4, characterized in that, The bisphenol A was measured, and the measurement results were obtained, including: At set time points, the reaction solution is pipetted into a centrifuge tube containing sodium thiosulfate for vortex mixing to obtain a mixture; wherein, the set time points include 0, 10, 20, 30, 40, 50, and 60 min after the chemical reaction is started; The mixture is filtered using a filter to obtain a filtrate; The filtrate was measured using high performance liquid chromatography (HPLC) to obtain the measurement results.

6. The method for the degradation of bisphenol A by persulfate in conjunction with tea residue and iron filings according to claim 1, characterized in that, The step of sieving the coarse tea residue powder to obtain tea residue powder includes: The coarse powder of tea residue is sieved using a sieve to obtain coarse powder that does not pass through the sieve and fine powder that passes through the sieve; the size range of the sieve is greater than or equal to 40 mesh and less than or equal to 100 mesh. Collect the sieved fine powder to obtain tea residue powder.

7. The method for degrading bisphenol A by tea residue and iron filings in conjunction with persulfate activation according to claim 1, characterized in that, The tea mentioned is green tea, oolong tea, yellow tea, black tea, white tea, or dark tea.

8. The method for degrading bisphenol A by tea residue and iron filings in conjunction with persulfate activation according to claim 3, characterized in that, The iron filings contain 97% ferric oxide.

9. The method for the degradation of bisphenol A by tea residue and iron filings in conjunction with the activation of persulfate according to claim 1, characterized in that, The persulfate is potassium persulfate or sodium persulfate.

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