Chlorine-oxygen double vacancy feocl catalyst, its preparation method and application in removal of organic pollutants in activated chlorite in water

Abstract

The application discloses a chlorine-oxygen double vacancy FeOCl catalyst and a preparation method and application thereof in removal of organic pollutants in water by activating chlorite, and relates to the technical field of organic wastewater treatment. The chlorine-oxygen double vacancy FeOCl catalyst is successfully constructed on the surface of FeOCl through a two-step method (heat treatment + reaction under illumination). The synergistic effect of the chlorine-oxygen double vacancy significantly enhances the activation capacity of FeOCl on chlorite, and the removal rate of the organic pollutants, especially antibiotic organic pollutants, is higher than that of FeOCl materials without illumination treatment. The chlorine-oxygen double vacancy FeOCl catalyst constructed in the application can simultaneously generate selective high-valence metal substances and ClO2 in the chlorite activation advanced oxidation system, realizes selective oxidative degradation of various representative organic pollutants, and can maintain high and stable removal performance in a wide pH range and various water body substrates, and exhibits good environmental adaptability.

Description

Technical Field

[0001] This invention relates to the field of organic wastewater treatment technology, and in particular to a chlorine-oxygen dual-vacancy FeOCl catalyst, its preparation method, and its application in the removal of organic pollutants from water by activating chlorite. Background Technology

[0002] With the acceleration of industrialization and urbanization, the pollution problem of recalcitrant organic pollutants (such as pharmaceuticals, personal care products, pesticides, and persistent organic pollutants) in water bodies is becoming increasingly serious, posing a severe threat to the ecological environment and human health. Traditional biological treatment methods have limited removal efficiency for recalcitrant organic pollutants, while physical adsorption methods only achieve phase transfer and cannot completely degrade recalcitrant organic pollutants. Therefore, developing efficient and thorough organic pollutant removal technologies has become a research hotspot.

[0003] Advanced oxidation processes (AEs) degrade organic pollutants by activating oxidants to generate highly oxidizing free radicals. This method is characterized by rapid reaction, wide applicability, and high mineralization. However, traditional AEs have significant limitations in practical applications: Firstly, the concentration of coexisting matrix in water is often much higher than the concentration of the target organic pollutant, inevitably leading to ineffective consumption of free radicals and significantly weakening the treatment effect of traditional AEs. Therefore, when treating trace amounts of organic matter in the environment, excessive oxidant dosage or additional energy input is usually required to maintain the treatment effect of traditional AEs, which increases treatment costs and causes secondary pollution. Secondly, while traditional AEs can achieve rapid degradation of organic pollutants, their degradation products may still possess biotoxicity and resistance gene induction capabilities. Therefore, developing selective advanced oxidation technologies for organic pollutants to achieve efficient and stable degradation of organic pollutants in water while simultaneously eliminating their biotoxicity is a key approach to the efficient and safe treatment of organic wastewater.

[0004] To achieve efficient degradation and rapid detoxification of organic pollutants, researchers have developed advanced oxidation processes based on selective oxide species, such as singlet oxygen, high-valence metal species, active chlorine species, and interfacial electron transfer. Compared with traditional advanced oxidation processes, selective advanced oxidation processes exhibit stronger resistance to water matrix interference and better biotoxicity reduction performance. Chlorite-activated selective advanced oxidation processes can generate chlorine dioxide, which features high steady-state concentration, long half-life, and selective electrophilic activity. The generated chlorine dioxide can induce the selective oxidation of electron-rich pharmacophores in organic pollutants, thereby achieving efficient degradation and effective elimination of biotoxicity. Chlorite can be activated by strong acids, ultraviolet light, and transition metal catalysts. Among these, transition metal-catalyzed activation of chlorite has attracted much attention due to its advantages of mild operation, controllable active sites, and high cost-effectiveness. However, this process faces the problem of slow reaction kinetics, mainly due to the limited number of surface active sites on transition metal catalysts, which are constrained by factors such as morphology, crystal size, and exposed crystal faces, preventing sufficient exposure. Therefore, designing and synthesizing catalysts with highly exposed and structurally stable active sites is of practical significance for improving the reaction kinetics of transition metal-catalyzed chlorite activation. Summary of the Invention

[0005] The purpose of this invention is to provide a chlorine-oxygen dual-vacancy FeOCl catalyst, its preparation method, and its application in the removal of organic pollutants from water by activating chlorite, so as to solve the problems existing in the prior art and meet the urgent need for selective oxidative degradation of organic pollutants.

[0006] To achieve the above objectives, the present invention provides the following solution: One of the technical solutions of the present invention: a method for preparing a chlorine-oxygen dual-vacancy FeOCl catalyst, comprising the following steps: Ferric chloride was heat-treated to obtain FeOCl powder (abbreviated as FOC); the FeOCl powder was dispersed in water and reacted under light to obtain the chlorine-oxygen dual-vacancy FeOCl catalyst (abbreviated as FO). v C v ).

[0007] This invention successfully constructed a dual-defect system of chloride and oxygen vacancies on the FeOCl surface using a two-step method. First, FeOCl containing a small number of chloride and oxygen vacancies was obtained through heat treatment. However, the limited number of active sites on the FeOCl surface and the slow kinetics of oxygen atom transfer to generate high-valence metal species limited the efficiency of FeOCl in activating chlorite. Building on this, further phototreatment was employed to introduce a large number of chloride-oxygen dual vacancies. These chlorine-oxygen dual vacancies can induce poorly coordinated iron atoms as active sites, thereby promoting the generation of chlorine dioxide (ClO2) and high-valence iron, accompanied by the generation of superoxide radicals. This significantly enhanced the activation ability of FeOCl for chlorite, resulting in a higher removal rate of organic pollutants, especially antibiotics, compared to untreated FeOCl materials. The chloride-oxygen dual-vacancy FeOCl catalyst activated by this invention can simultaneously generate selective high-valence metals and ClO2, achieving selective oxidative degradation of various representative organic pollutants. It maintains high and stable removal performance over a wide pH range and in various aquatic matrices, demonstrating good environmental adaptability.

[0008] Furthermore, the heat treatment temperature is 200-300 ℃, and the holding time is 1-3 h.

[0009] Furthermore, the illumination conditions include: a wavelength of 420-800 nm and an optical power of 100 mW / cm². 2 .

[0010] Furthermore, the reaction time under light is 1-4 hours.

[0011] Furthermore, the reaction process under light is carried out under stirring conditions.

[0012] Furthermore, after the reaction under light, the process includes washing and drying steps, wherein the drying temperature is 80 °C.

[0013] Furthermore, the ferric chloride is anhydrous ferric chloride, obtained by dissolving FeCl3·6H2O in water and heating and drying until the water is completely removed; the heating and drying temperature is 70-90 ℃.

[0014] The second technical solution of the present invention: a chlorine-oxygen dual-vacancy FeOCl catalyst prepared by the above-described method.

[0015] The third technical solution of the present invention: the application of the above-mentioned chlorine-oxygen dual-vacancy FeOCl catalyst in the removal of organic pollutants from water by activating chlorite.

[0016] The fourth technical solution of the present invention: a method for removing organic pollutants from water based on chlorite activated by a chlorine-oxygen dual-vacancy FeOCl catalyst, comprising the following steps: A chlorine-oxygen dual-vacancy FeOCl catalyst was added to wastewater containing organic pollutants (referred to as organic wastewater), and after stirring and adsorption, chlorite was added to carry out the oxidative degradation of organic pollutants. The chlorine-oxygen dual-vacancy FeOCl catalyst is the chlorine-oxygen dual-vacancy FeOCl catalyst described above.

[0017] Furthermore, the dosage of the chlorine-oxygen dual-vacancy FeOCl catalyst in the wastewater is 0.1-0.5 g / L.

[0018] Furthermore, the concentration of organic pollutants in the wastewater is 5-30 mg / L.

[0019] Furthermore, the chlorite includes sodium chlorite.

[0020] Furthermore, the dosage of the chlorite in the wastewater is 0.1-1.0 mM, preferably 0.3-1.0 mM.

[0021] Furthermore, the oxidative degradation is carried out under stirring conditions at room temperature.

[0022] Furthermore, the organic pollutants include phenol, p-hydroxyacetophenone, p-hydroxybenzoic acid, sulfadiazine, sulfonamide, bisphenol A, sulfadiazine, or sulfamethoxazole.

[0023] Furthermore, the pH value of the wastewater is 3-8.

[0024] The present invention discloses the following technical effects: This invention successfully constructed a dual-defect system of chloride and oxygen vacancies on the FeOCl surface using a two-step method. The synergistic effect of the chloride-oxygen dual vacancies significantly enhanced the activation ability of FeOCl for chlorite, resulting in a higher removal rate of organic pollutants, especially antibiotic-like organic pollutants, compared to FeOCl materials without phototreatment. The chloride-oxygen dual-vacancy FeOCl catalyst constructed in this invention can simultaneously generate selective high-valence metals and ClO2 in the activated chlorite advanced oxidation system, achieving selective oxidative degradation of various representative organic pollutants. It maintains highly efficient and stable removal performance over a wide pH range and in various aquatic matrices, demonstrating good environmental adaptability. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 FOC and FO prepared in Example 1 v C v X-ray diffraction pattern of the catalyst.

[0027] Figure 2 FOC and FO prepared in Example 1 v C v Electron paramagnetic resonance spectrum of the catalyst -3.

[0028] Figure 3 The image shows the K-edge EXAFS fitted spectrum of Fe in the FOC catalyst prepared in Example 1.

[0029] Figure 4 FO prepared in Example 1 v C v -3 K-edge EXAFS fitted spectrum of Fe in catalyst -3

[0030] Figure 5 To obtain FO under different illumination times v C v The effects of catalyst and FOC on the removal of sulfadiazine by activated chlorite.

[0031] Figure 6 Contains only chlorine vacancies (FOC) v ), containing only oxygen vacancies (FO) v C) and containing oxychloride double vacancy (FO) v C v The effect of FeOCl catalyst on the removal of sulfadiazine by activated chlorite.

[0032] Figure 7 Contains only chlorine vacancies (FOC) v ), containing only oxygen vacancies (FO) v C) and containing oxychloride double vacancy (FO) v C v A pseudo-first-order kinetic model of the effect of FeOCl catalyst on the removal of sulfadiazine by activated chlorite.

[0033] Figure 8 For different FO v C v Catalyst dosage on FOv C v The effect of activated chlorite on the removal of sulfadiazine.

[0034] Figure 9 For different chlorite dosages, the effect on FO v C v The effect of activated chlorite on the removal of sulfadiazine.

[0035] Figure 10 For FO v C v The removal effect of activated chlorite on different types of representative organic pollutants.

[0036] Figure 11 pH to FO v C v The effect of activated chlorite on the removal of sulfadiazine.

[0037] Figure 12 For the background substances of water body on FO v C v The effect of activated chlorite on the removal of sulfadiazine. Detailed Implementation

[0038] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0039] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0040] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0041] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0042] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0043] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0044] Unless otherwise specified, the room temperature mentioned in the following embodiments and application examples of the present invention refers to 20-30°C.

[0045] All raw materials used in the following embodiments and application examples of the present invention are commercially available products.

[0046] Example 1 A chlorine-oxygen dual-vacancy FeOCl catalyst is prepared by the following steps: 5 g of FeCl3·6H2O was dissolved in 5 mL of water and stirred until completely dissolved. The solution was then dried in an oven at 80 °C until all moisture was removed. The solution was transferred to a crucible, which was placed in a muffle furnace and heated to 250 °C. After heat treatment at this temperature for 2 h, the solution was allowed to cool naturally to room temperature to obtain FeOCl powder (FOC). 500 mg of FeOCl powder was dispersed in 60 mL of water, and a xenon lamp was turned on at a wavelength of 420-800 nm and a light power of 100 mW / cm². 2 The mixture was stirred and irradiated with light for 3 hours. After the light exposure, the resulting sample was washed with deionized water and dried in an oven at 80 °C to obtain FeOCl containing chlorine-oxygen double vacancies (abbreviated as FO). v C v -3), which is a chlorine-oxygen double-vacancy FeOCl catalyst.

[0047] Figure 1 The FOC and FO prepared in this embodiment v C v The X-ray diffraction pattern of the catalyst -3 shows that the FOC diffraction peaks are located at 11.17°, 26.10°, 35.37°, 37.89°, and 50.38°, corresponding to the (010), (110), (021), (111), and (131) planes of FeOCl (PDF#72-0619). Under visible light etching, FOC... v C v-3 exhibits a significant decrease in characteristic peak intensity compared to FOC, mainly due to FO v C v -3 Formation of vacancy.

[0048] Figure 2 The FOC and FO prepared in this embodiment v C v The electron paramagnetic resonance spectrum of the catalyst -3 shows that FOC and FO v C v -3 exhibits a significant symmetric Lorentz signal (g=2.003), which originates from unpaired local electrons in vacancies. The number of unpaired electrons was quantitatively analyzed by double integration of the EPR signal. v C v The number of unpaired electrons in -3 (0.0852) is higher than that in FOC (0.0557), indicating that visible light etching induces the generation of vacancies.

[0049] Figure 3 and Figure 4 The FOC and FO prepared in this embodiment are respectively v C v The K-edge EXAFS fitted spectrum of Fe in the catalyst -3 shows that, compared with FOC, FO v C v The coordination number of the Fe-O shell in -3 decreases from 3.9 to 3.6, which is attributed to the formation of oxygen vacancies. Therefore, due to the relaxation of the iron atom structure and the weakening of the Coulomb shielding effect, FO v C v The length of the Fe-O bond in -3 increases from 1.98 Å to 2.25 Å. Furthermore, the Fe-Cl bond in FO... v C v The number of Fe-Cl remained unchanged at -3 (2.29 Å), while the coordination number of Fe-Cl decreased significantly from 1.1 to 0.3 after visible light etching, which confirms the simultaneous formation of chlorine vacancies.

[0050] Example 2 Same as Example 1, except that the illumination time under the xenon lamp is 1 hour, and the resulting FeOCl is abbreviated as FO. v C v -1.

[0051] Example 3 Same as Example 1, except that the illumination time under the xenon lamp is 2 hours, and the resulting FeOCl is abbreviated as FO. v C v -2.

[0052] Example 4 Same as Example 1, except that the illumination time under the xenon lamp was 4 hours, and the resulting FeOCl was abbreviated as FO. v C v -4.

[0053] Comparative Example 1 The preparation steps of FeOCl catalyst containing only oxygen vacancies are as follows: Dissolve 5 g of FeCl3·6H2O in 5 mL of water and stir until completely dissolved. Dry in an oven at 80 °C until all moisture is removed. Transfer the solution to a crucible and place it in a muffle furnace. Heat the crucible to 250 °C and maintain the temperature for 2 h. Then, allow it to cool naturally to room temperature to obtain FeOCl powder. Disperse 500 mg of FeOCl powder in 60 mL of water and add 1 mol of NaCl solution. Turn on a xenon lamp with a wavelength of 420-800 nm and an optical power of 100 mW / cm². 2 The mixture was stirred and irradiated with light for 3 hours. After the light exposure, the resulting sample was washed with deionized water and dried in an oven at 80 °C to obtain FeOCl containing only oxygen vacancies (abbreviated as FO). v C).

[0054] Comparative Example 2 The preparation steps of FeOCl catalyst containing only chlorine vacancies are as follows: 5 g of FeCl3·6H2O was dissolved in 5 mL of water and stirred until completely dissolved. The solution was then dried in an oven at 80 °C until all moisture was removed. The solution was transferred to a crucible, which was placed in a muffle furnace and heated to 250 °C. After heat treatment at this temperature for 2 h, the solution was allowed to cool naturally to room temperature to obtain FeOCl powder (FOC). 500 mg of FeOCl powder was dispersed in 60 mL of water, and a xenon lamp was turned on at a wavelength of 420-800 nm and a light power of 100 mW / cm². 2 The mixture was stirred and irradiated with light for 3 hours. After the light exposure, the resulting sample was washed with deionized water and dried in an oven at 80 °C to obtain FO. v C v FO v C v The sample was soaked in 30 mL of H₂O₂ (9.8 mol / L) for 12 hours, then filtered and dried at 80 °C to obtain FeOCl containing only chlorine vacancies (abbreviated as FOC). v ).

[0055] Application Example 1 The method for removing organic pollutants from water based on FeOCl catalyst activation with chlorite (oxychloride dual-vacancy site) comprises the following steps: A sulfadiazine (SDZ) aqueous solution with pH = 7 and a concentration of 10 mg / L was prepared as simulated organic wastewater. Catalysts (FOC, FO) were then added to the organic wastewater. v C v -1、FO v C v -2、FO v C v -3 or FO v C v -4, the catalyst dosage in the organic wastewater was 0.3 g / L), and the mixture was stirred at room temperature for 30 min to reach adsorption equilibrium. Then, sodium chlorite (sodium chlorite dosage in the organic wastewater was 1.0 mmol / L) was added, and stirring was continued at room temperature to carry out the oxidative degradation of organic pollutants. Samples were taken at 5, 10, 15, 30, 45, and 60 min after the start of degradation, and the concentration of SDZ was detected by liquid chromatography.

[0056] Figure 5 To obtain FO under different illumination times v C v The effect of catalyst and FOC on the removal of sulfadiazine by activated chlorite (Figure [SDZ]) t [SDZ]0 represents the sulfadiazine concentration after a specific reaction time (where [SDZ]0 represents the sulfadiazine concentration at the initial time). It can be seen that each FO... v C v The catalyst achieved 100% removal of sulfadiazine within 60 minutes, demonstrating that FO v C v The activation of chlorite was achieved, and the activation effect was significantly better than that of FOC.

[0057] Application Example 2 Contains only chlorine vacancy (FOC) v ), containing only oxygen vacancies (FO) v C) and containing oxychloride double vacancy (FO) v C v The effect of FeOCl catalyst on the removal of sulfadiazine by activated chlorite was tested using the following steps: A sulfadiazine aqueous solution with pH = 7 and a concentration of 10 mg / L was prepared as simulated organic wastewater. FeOCl catalysts (FO) with different vacancy conditions were then added to the organic wastewater. v C, FOC v or FO v C v-3, the catalyst dosage in the organic wastewater was 0.3 g / L), and the mixture was stirred at room temperature for 30 min to reach adsorption equilibrium. Then, sodium chlorite (1.0 mmol / L in the organic wastewater) was added, and stirring was continued at room temperature to carry out the oxidative degradation of organic pollutants.

[0058] Figure 6 Contains only chlorine vacancies (FOC) v ), containing only oxygen vacancies (FO) v C) and containing oxychloride double vacancy (FO) v C v The effect of FeOCl catalyst on the removal of sulfadiazine by activated chlorite can be seen that FOCl... v and FO v The degradation effect of C was worse than that of FO. v C v -3.

[0059] Figure 7 Contains only chlorine vacancies (FOC) v ), containing only oxygen vacancies (FO) v C) and containing oxychloride double vacancy (FO) v C v A pseudo-first-order kinetic model of the effect of FeOCl catalyst on the removal of sulfadiazine from activated chlorite was used (in the figure, C is the concentration of sulfadiazine after a specific reaction time, and C0 is the concentration of sulfadiazine at the initial time). It can be seen that the degradation rate constant of FeOCl material containing chlorine-oxygen double vacancies for organic matter degradation is 0.152 min. −1 Compared to FO v C and FOC v All showed significant improvement.

[0060] Application Example 3 The effect of different catalyst dosages on FO v C v The effect of activated chlorite on the removal of sulfadiazine was investigated using the following test procedures: A sulfadiazine aqueous solution with pH = 7 and a concentration of 10 mg / L was prepared as simulated organic wastewater. Different amounts of FO were added to the organic wastewater. v C v -3 (FO) v C v -3 was added to the organic wastewater at dosages of 0.1 g / L, 0.2 g / L, 0.3 g / L, 0.4 g / L, or 0.5 g / L, respectively, and stirred at room temperature for 30 min to reach adsorption equilibrium. Then, sodium chlorite (1.0 mmol / L in the organic wastewater) was added, and stirring was continued at room temperature to carry out the oxidative degradation of organic pollutants.

[0061] Figure 8 For different FO v C v Catalyst dosage on FO v C v The effect of activated chlorite on the removal of sulfadiazine can be seen as follows: with FO v C v Increasing the catalyst dosage significantly improves the sulfadiazine removal efficiency.

[0062] Application Example 4 The effect of different chlorite dosages on FO v C v The effect of activated chlorite on the removal of sulfadiazine was investigated using the following test procedures: Prepare a sulfadiazine aqueous solution with pH = 7 and a concentration of 10 mg / L as simulated organic wastewater. Add FO to the organic wastewater. v C v -3 (FO) v C v -3 was added to the organic wastewater at a dosage of 0.3 g / L, and stirred at room temperature for 30 min to reach adsorption equilibrium. Then, different amounts of sodium chlorite (0.1 mmol / L, 0.3 mmol / L, 0.5 mmol / L, 0.7 mmol / L, or 1.0 mmol / L in the organic wastewater) were added, and stirring was continued at room temperature to carry out the oxidative degradation of organic pollutants.

[0063] Figure 9 For different chlorite dosages, the effect on FO v C v The effect of activated chlorite on the removal of sulfadiazine shows that the removal efficiency of sulfadiazine is significantly improved with the increase of sodium chlorite dosage.

[0064] Application Example 5 FO v C v The removal efficiency of activated chlorite on different representative organic pollutants was tested using the following steps: Prepare 100 μmol / L aqueous solutions of phenol, p-hydroxyacetophenone, p-hydroxybenzoic acid, sulfadiazine, sulfonamide, bisphenol A, sulfadiazine, or sulfamethoxazole at pH = 7 as simulated organic wastewater. Add FO to each of these organic wastewater solutions. v C v -3 (FO) v C v-3 was added at a dosage of 0.3 g / L to each organic wastewater, and stirred at room temperature for 30 min to reach adsorption equilibrium. Then sodium chlorite (1.0 mmol / L) was added, and stirring was continued at room temperature to carry out the oxidative degradation of each organic pollutant.

[0065] Figure 10 For FO v C v The removal effects of activated chlorite on different types of representative organic pollutants show that this oxidation system has universal applicability in pollutant degradation.

[0066] Application Example 6 pH on FO v C v The effect of activated chlorite on the removal of sulfadiazine was investigated using the following test procedures: Prepare sulfadiazine aqueous solutions with a concentration of 10 mg / L, and adjust the pH to 3, 4, 5, 6, and 8 respectively to simulate organic wastewater. Add FO to each organic wastewater solution. v C v -3 (FO) v C v -3 was added at a dosage of 0.3 g / L to each organic wastewater, and stirred at room temperature for 30 min to reach adsorption equilibrium. Then sodium chlorite (1.0 mmol / L) was added, and stirring was continued at room temperature to carry out the oxidative degradation of organic pollutants.

[0067] Figure 11 pH to FO v C v The effect of activated chlorite on the removal of sulfadiazine demonstrates that the oxidation system can maintain highly efficient and stable sulfadiazine removal performance over a wide pH range.

[0068] Application Example 7 Water background material on FO v C v The effect of activated chlorite on the removal of sulfadiazine was investigated using the following test procedures: A sulfadiazine aqueous solution with pH = 7 and a concentration of 10 mg / L was prepared as simulated organic wastewater. Background substances Cl- were added to the organic wastewater. - SO4 2- Or NO3 - (The dosage of each background substance in the organic wastewater was 1 mmol / L), and then FO was added to the organic wastewater after the addition of different background substances. v C v -3 (FO) v C v-3 was added at a dosage of 0.3 g / L to each organic wastewater, and stirred at room temperature for 30 min to reach adsorption equilibrium. Then sodium chlorite (1.0 mmol / L) was added, and stirring was continued at room temperature to carry out the oxidative degradation of organic pollutants.

[0069] Figure 12 For the background substances of water body on FO v C v The effect of activated chlorite on the removal of sulfadiazine (where blank represents no background substance added) shows that this oxidation system can effectively resist the presence of Cl in the water. - NO3 - The interference effect can resist SO4 to a certain extent. 2- The interference effect.

[0070] The above examples and application cases illustrate that the synergistic effect of chlorine-oxygen dual vacancies significantly improves the activation efficiency of chlorite, resulting in a better removal rate of organic pollutants than untreated FeOCl (i.e., FOC) materials. Using FO v C v Using sodium chlorite as a catalyst and sodium chlorite as an oxidant, FO was constructed. v C v The activated chlorite advanced oxidation system can simultaneously generate selective high-valence metals and ClO2, achieving selective oxidative degradation of various representative organic pollutants. It maintains high and stable removal performance across a wide pH range and in various water substrates (containing different background substances), demonstrating good environmental adaptability. This invention provides a green, efficient, and highly selective advanced oxidation technology that achieves targeted removal of organic pollutants from wastewater.

[0071] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing a chlorine-oxygen dual-vacancy FeOCl catalyst, characterized in that, Includes the following steps: Ferric chloride was heat-treated to obtain FeOCl powder; the FeOCl powder was dispersed in water and reacted under light to obtain the chlorine-oxygen dual-vacancy FeOCl catalyst.

2. The preparation method of the chlorine-oxygen dual-vacancy FeOCl catalyst as described in claim 1, characterized in that, The heat treatment temperature is 200-300 ℃, and the holding time is 1-3 h.

3. The preparation method of the chlorine-oxygen dual-vacancy FeOCl catalyst as described in claim 1, characterized in that, The illumination conditions include: wavelength of 420-800 nm and optical power of 100 mW / cm². 2 .

4. The preparation method of the chlorine-oxygen dual-vacancy FeOCl catalyst as described in claim 1, characterized in that, The reaction time under light is 1-4 hours.

5. The preparation method of the chlorine-oxygen dual-vacancy FeOCl catalyst as described in claim 1, characterized in that, The ratio of FeOCl powder to water is 50 mg: 5-7 mL.

6. A chlorine-oxygen dual-vacancy FeOCl catalyst prepared by the method described in any one of claims 1-5.

7. The application of the chlorine-oxygen dual-vacancy FeOCl catalyst as described in claim 6 in the removal of organic pollutants from water by activating chlorite.

8. A method for removing organic pollutants from water based on the activation of chlorite using a chlorine-oxygen dual-vacancy FeOCl catalyst, characterized in that, Includes the following steps: A chlorine-oxygen dual-vacancy FeOCl catalyst was added to wastewater containing organic pollutants. After stirring and adsorption, chlorite was added to carry out the oxidative degradation of organic pollutants. The chlorine-oxygen dual-vacancy FeOCl catalyst is the chlorine-oxygen dual-vacancy FeOCl catalyst as described in claim 6.

9. The method for removing organic pollutants from water based on the activation of chlorite using a chlorine-oxygen dual-vacancy FeOCl catalyst as described in claim 8, characterized in that, The dosage of the chlorine-oxygen dual-vacancy FeOCl catalyst in the wastewater is 0.1-0.5 g / L.

10. The method for removing organic pollutants from water based on the activation of chlorite by a chlorine-oxygen dual-vacancy FeOCl catalyst as described in claim 8, characterized in that, The chlorite includes sodium chlorite; And / or, the dosage of the chlorite in the wastewater is 0.1-1.0 mM.

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