Method for degrading aromatic organic pollutants in water by activating persulfate through nonmetal heteroatom coordinated diatomic catalyst

Abstract

The invention belongs to the field of water environment treatment, and particularly relates to a method for activating aromatic organic pollutants in persulfate degradation water by using a nonmetal heteroatom coordinated diatomic catalyst. The preparation method comprises the following steps: co-doping two transition metals on a carbon-based carrier through non-metal phosphorus atom coordination, and carrying out high-temperature calcination in an inert gas environment to obtain the non-metal heteroatom coordinated diatomic catalyst. The transition metal Fe is combined with any one of Co and Ni; the carbon-based carrier is a metal organic framework ZIF-8. The preparation method disclosed by the invention is simple in step, convenient to operate, quick in treatment effect, high in product yield and low in cost, and has good economic value and social benefit. Compared with the traditional monatomic catalyst and nano-catalyst, the diatomic catalyst prepared by the invention has the advantages of uniform active sites, atomic-scale dispersion, excellent catalytic effect and the like, and can be a key technology for eliminating organic pollution to the water environment in the industries of chemistry, chemical engineering, pharmacy and the like.

Description

Technical Field

[0001] The invention belongs to the field of water environment treatment, and specifically relates to a method and application of preparation of a diatomic catalyst coordinated by non-metallic heteroatoms and activation of persulfate to degrade aromatic organic pollutants in water. Background Art

[0002] Persistent organic pollutants, antibiotics, endocrine disruptors and other organic pollutants are important types of new pollutants introduced by the country in recent years. They can enter aquatic ecosystems through atmospheric dry and wet deposition, surface runoff and direct exchange at the water-air interface, have direct toxic effects on aquatic organisms and microbial communities, and have effects on human health such as nervous system damage, reproductive system and immune dysfunction, neurobehavioral developmental disorders, endocrine disorders and cancer. At the same time, new organic pollutants also bring potential risks to human health, including increasing human resistance to antibiotics and possible immune system abnormalities and fertility problems. Therefore, how to efficiently, thoroughly and non-toxicly treat new organic pollutants in the water environment is an important issue.

[0003] The removal of organic pollutants in water bodies usually adopts physicochemical treatment technology or physicochemical treatment coupled with biochemical treatment. Advanced oxidation technology similar to Fenton reaction is an important treatment method. It mainly produces active oxygen species through catalyst activation of oxidants (such as hydrogen peroxide and persulfate (PMS)) to oxidize and degrade organic pollutants. Active oxygen species such as hydroxyl radicals and superoxide radicals usually have a good degradation effect on electron-rich organic pollutants, but the effect is general on aromatic ring organic pollutants that are difficult to biodegrade in water bodies, especially for aromatic ring compounds containing some electron-withdrawing groups, such as phenol, nitrobenzene and p-chlorophenol. The electron-withdrawing groups cause the main structure of organic pollutants to be electron-deficient, and the active oxygen species are difficult to effectively degrade. Summary of the invention

[0004] The purpose of the present invention is to provide a method and application of preparing a diatomic catalyst coordinated by non-metallic heteroatoms and activating persulfate to degrade aromatic organic pollutants in water. The diatomic catalyst prepared by the present invention has the characteristics of atomic-level dispersion and can efficiently remove aromatic organic pollutants. The diatomic catalyst coordinated by non-metallic heteroatoms designed in the present invention can achieve asymmetric distribution of electrons through heterogeneous diatomic sites, thereby achieving rapid and efficient removal of various aromatic organic pollutants. It has excellent degradation effect and can achieve rapid degradation of various pollutants within 1 minute.

[0005] In order to achieve the above object, the present invention provides the following technical solution: a method for degrading aromatic organic pollutants in water by activating persulfate with a diatomic catalyst coordinated by a non-metallic heteroatom, comprising the following steps:

[0006] (1) dissolving a carbon-based carrier ZIF-8 and a transition metal compound in methanol and mixing them for reaction, collecting the insoluble matter and calcining at high temperature to obtain a diatomic catalyst; the transition metal compound is (1,1'-bis(diphenylphosphino)ferrocene) chloride X, wherein X is one of Co and Ni;

[0007] (2) Add diatomic catalysts and persulfate to the polluted water to oxidize and eliminate aromatic organic pollutants in the water.

[0008] Preferably, the mass ratio of the carbon-based carrier ZIF-8 to the transition metal compound is 1:0.01~0.1;

[0009] The mass ratio of the carbon-based carrier ZIF-8 to methanol is 1:10-500;

[0010] The mass concentration / molar concentration of the diatomic catalyst and the persulfate is 0.01-1 g / L: 0.1-1.0 mmol / L.

[0011] Preferably, the calcination temperature is 800-1000°C and the calcination time is 2-5 h.

[0012] Preferably, the persulfate is potassium permonosulfate (PMS).

[0013] Preferably, the diatomic catalyst is ZIF-Fe-P-Ni or ZIF-Fe-P-Co; the specific preparation method is as follows:

[0014] 2 g of ZIF-8 was weighed and dissolved in 300 mL of methanol. Then 0.44 mmol of (1,1'-bis(diphenylphosphino)ferrocene) nickel dichloride or (1,1'-bis(diphenylphosphino)ferrocene) cobalt dichloride (II) was weighed and dissolved in 200 mL of methanol. The two were then stirred for 5 min and mixed by ultrasonic for 10 min. The mixture was stirred vigorously at 40 °C for 16 h. The solid product was collected by filtration, washed with methanol 5 times, and dried. Finally, the evenly ground solid was placed in a tubular furnace and heated at a heating rate of 5 °C / min at an argon flow rate of 100 mL / min to 950 °C for 3 h. After cooling to room temperature, the diatomic catalyst ZIF-Fe-P-Ni or ZIF-Fe-P-Co was obtained.

[0015] Preferably, the diatomic catalyst has an atomic dispersion effect, and can achieve rapid degradation and removal of a variety of aromatic organic pollutants within 1 minute.

[0016] Preferably, the method comprises the following steps: adding a diatomic catalyst to water containing organic pollutants, fully mixing and stirring, and then adding persulfate, wherein the oxidant is activated by the diatomic catalyst to generate a large number of free radicals and non-free radicals, which attack and destroy the structure of aromatic organic pollutants to achieve the purpose of efficient degradation.

[0017] Preferably, the pollutants include fluoroquinolone antibiotics, sulfonamide antibiotics, and p-chlorophenol organic pollutants.

[0018] Preferably, evenly ground ZIF-Fe-P-Ni is added to water bodies contaminated by SMX, NOR and 4-CP, respectively, so that the concentration of ZIF-Fe-P-Ni in the reaction system is 0.1 g / L, and then PMS is added to make the concentration of PMS in the reaction system 0.1-0.4 mM. Stirring for 1 min can complete 100% removal of organic pollutants in SMX and 4-CP polluted water bodies, and stirring for 5 minutes can complete 100% removal of organic pollutants in NOR polluted water bodies.

[0019] Compared with the prior art, the present invention has the following characteristics and beneficial effects:

[0020] (1) It can be mass-produced and applied on a large scale.

[0021] (2) Different from the general multi-step calcination method, the present invention adopts a one-step calcination method, the synthesis steps are simple, and the synthesis reaction conditions are easy to achieve.

[0022] (3) The material itself is non-toxic and can be recycled.

[0023] (4) Multiple metals are evenly dispersed on the carrier to achieve efficient atomic utilization.

[0024] (5) The process of removing aromatic organic pollutants from water bodies is simple, the technology is simple, and it is easy to achieve a 100% removal rate of pollutants under natural conditions.

[0025] (6) The diatomic catalyst activated persulfate prepared by the present invention can oxidatively degrade various types of organic pollutants that are difficult to remove in water bodies, such as quinolone antibiotics, sulfonamide antibiotics and phenolic compounds.

[0026] (7) This technical method has a high oxidation degradation rate for aromatic organic pollutants in polluted water bodies, and can achieve 100% degradation efficiency within 1 minute.

[0027] (8) The present invention uses a metal ligand compound containing P to react with ZIF-8 to prepare a diatomic catalyst coordinated by a non-metallic P heteroatom. The doping of non-metal leads to uneven electron distribution of transition metal atoms, which makes it easier to induce electron migration, thereby promoting the catalytic effect.

[0028] (9) This technical method can be used to prepare a variety of diatomic catalysts with excellent effects, such as ZIF-Fe-P-Co, ZIF-Fe-P-Ni, etc.

[0029] (10) Figure 4 The figure shows the adsorption effect of 0.1 g / L single-atom and double-atom catalysts on 10 mg / L 4-CP without adding PMS. The adsorption effect of the catalyst on pollutants is about 20%. Figure 5 The figure shows the degradation of 4-CP by 0.1 g / L single and double atom catalysts. Among them, ZIF-Fe-P-Ni can achieve 100% removal of 4-CP in about 30 seconds. The degradation effect is very obvious, indicating that the oxidative degradation step accounts for the main contribution to the removal of aromatic organic pollutants, rather than a simple adsorption process that may cause secondary pollution to the environment.

[0030] In addition, compared with the existing aromatic organic pollutant removal technology, the technical method provided by the present invention does not need to premix the catalyst and the pollutant for a long time in advance, but directly adds the diatomic catalyst and persulfate to the polluted water body, and can achieve 100% removal of aromatic pollutants in a short time; in the elimination mechanism of aromatic organic pollutants, the present invention adopts a metal ligand compound containing P, and reacts with ZIF-8 to obtain a diatomic catalyst containing non-metallic P heteroatom coordination, and the doping of non-metallic causes uneven distribution of electrons of transition metal atoms, which is more likely to cause electron migration and destroy the chemical structure of aromatic organic pollutants, thereby promoting catalytic oxidation degradation effect. Therefore, the diatomic material of the present invention can remove a variety of aromatic organic pollutants, such as quinolone antibiotics, sulfonamide antibiotics and phenolic compounds, and has a non-specific and efficient elimination effect on single organic pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. 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 creative labor.

[0032] Figure 1 XRD diagrams of single-atom and diatomic catalysts with different coordination environments and different transition metal coordination amounts.

[0033] Figure 2 Fourier transform infrared (FTIR) spectra of single and diatomic catalysts with different coordination environments and different transition metal coordination amounts.

[0034] Figure 3The effect diagram of 0.1 g / L ZIF-Fe-P-Ni dual-atom catalyst catalyzing 0.4 mM PMS to degrade 10 mg / L sulfamethoxazole (SMX, sulfonamide antibacterial agent), norfloxacin (NOR, quinolone antibiotic) and p-chlorophenol (4-CP).

[0035] Figure 4 This is a diagram showing the effect of single and double atom catalysts with different coordination environments catalyzing 0.1 mM PMS to degrade 10 mg / L 4-CP.

[0036] Figure 5 This is a diagram showing the adsorption effect of 0.1 g / L single-atom and diatomic catalysts with different coordination environments on 10 mg / L 4-CP.

[0037] Figure 6 This is a diagram showing the effect of 0.1 g / L ZIF-Fe-P-Ni atomic catalyst catalyzing different concentrations of PMS to degrade 10 mg / L 4-CP.

[0038] Figure 7 This is a diagram showing the effect of different dosages of ZIF-Fe-P-Ni diatomic catalysts catalyzing the degradation of 10 mg / L 4-CP by 0.1 mM PMS.

[0039] Figure 8 This is a diagram showing the effect of 0.1 g / L of diatomic catalysts coordinated with different masses of transition metals on the degradation of 10 mg / L 4-CP by 0.1 mM PMS. DETAILED DESCRIPTION

[0040] The present invention is further illustrated by examples below. The preparation of the diatomic catalyst provided by the present invention and the technical method for degrading aromatic organic pollutants are described in detail in combination with the drawings and examples, but they should not be understood as limiting the scope of protection of the present invention.

[0041] Example 1

[0042] Weigh 12.75 g Zn(NO3)6H2O and dissolve it in 1 L pure water. Then weigh 29.15 g 2-methylimidazole and dissolve it in 1 L pure water. Stir the two for 5 min and mix them. Stir rapidly for 2 h and let stand for 12 h. Pour out the supernatant, wash with water by centrifugation 3 times, collect the precipitate and dry it to obtain the carbon-based carrier ZIF-8.

[0043] Weigh 2 g of ZIF-8 and dissolve it in 300 mL of methanol, then weigh 0.44 mmol (1,1'-bis(diphenylphosphino)ferrocene) nickel dichloride and dissolve it in 200 mL of methanol, then stir the two separately for 5 min and mix them by ultrasonic for 10 min, stir vigorously at 40 ° C for 16 h, collect the solid product by suction filtration, wash it with methanol 5 times, and dry it. Finally, put the evenly ground solid into a tube furnace, heat it at a heating rate of 5 ° C / min under an argon flow rate (100 mL / min), heat it to 950 ° C for 3 h, and cool it to room temperature to obtain the diatomic catalyst ZIF-Fe-P-Ni;

[0044] Add evenly ground ZIF-Fe-P-Ni to water bodies polluted with concentrations of 10 mg / L SMX, NOR and 4-CP, respectively, so that the concentration of ZIF-Fe-P-Ni in the reaction system is 0.1 g / L, then add PMS, so that the concentration of PMS in the reaction system is 0.4 mM, and stir for 1 min to complete 100% removal of organic pollutants in SMX and 4-CP polluted water bodies, and stir for 5 min to complete 100% removal of organic pollutants in NOR polluted water bodies. Figure 3 shown.

[0045] Example 2

[0046] Weigh 12.75 g of Zn(NO3)6H2O and dissolve it in 1 L of pure water. Then weigh 29.15 g of 2-methylimidazole and dissolve it in 1 L of pure water. Stir the two for 5 min and mix them. Stir rapidly for 2 h and let stand for 12 h. Pour out the supernatant, wash with water by centrifugation 3 times, collect the precipitate and dry it to obtain the carbon-based carrier ZIF-8.

[0047] Weigh 2g of ZIF-8 and dissolve it in 300 mL of methanol, then weigh 0.44mmol (1,1'-bis(diphenylphosphino)ferrocene) nickel dichloride / cobalt (II) and dissolve it in 200 mL of methanol, then stir the two separately for 5 min and mix them by ultrasonic for 10 min, stir vigorously at 40°C for 16 h, collect the solid product by filtration, wash it with methanol 5 times, and dry it. Finally, put the evenly ground solid into a tube furnace, heat it at a heating rate of 5°C / min under an argon flow rate (100 mL / min), heat it to 950°C for 3 h, and cool it to room temperature to obtain the diatomic catalysts ZIF-Fe-P-Ni and ZIF-Fe-P-Co;

[0048] The synthesis of other single-atom catalysts mainly changes the types of metal ligand compounds, but the total molar number of metal ions is the same as that of the dual-atom catalysts. That is, 0.88 mmol of ferrocene is used for the synthesis of the ZIF-Fe catalyst, 0.88 mmol of (1,1'-bis(diphenylphosphino)ferrocene) is used for the synthesis of the ZIF-Fe-P catalyst, and 0.88 mmol of nickel dichloride hexahydrate is used for the synthesis of the ZIF-Ni catalyst. The remaining steps are the same as those for the synthesis of the dual-atom catalysts;

[0049] Add the well-ground ZIF, ZIF-Fe, ZIF-Ni, ZIF-Fe-P, ZIF-Fe-P-Co, and ZIF-Fe-P-Ni to the water body polluted by 4-CP, so that the concentration of the above catalysts in the reaction system is 0.1 g / L, and then add PMS so that the concentration of PMS in the reaction system is 0.1 mM. In addition, the adsorption performance of the above catalysts on 4-CP without adding PMS was also investigated. As Figure 4 shown, when PMS is not added, the adsorption and removal rate of 4-CP by all catalysts is about 20%, indicating that the adsorption ability of the above single-atom catalysts on 4-CP is relatively weak. When PMS is added, as Figure 5 shown, the removal rate of 4-CP by the above single-atom catalysts increases, indicating that the catalytic oxidation process occurs. Among them, the catalytic effect order is: ZIF < ZIF-Fe < ZIF-Ni < ZIF-Fe-P < ZIF-Fe-P-Co < ZIF-Fe-P-Ni. It can be seen that ZIF-Fe-P-Ni has the best removal effect on 4-CP, and can achieve 100% removal efficiency of organic pollutants in the 4-CP-polluted water body within 30 seconds.

[0050] Example 3

[0051] Weigh 12.75 g of Zn(NO3)·6H2O and dissolve it in 1 L of pure water. Then weigh 29.15 g of 2-methylimidazole and dissolve it in 1 L of pure water. After stirring each of them for 5 min, mix them, stir rapidly for 2 h, and then let it stand for 12 h. Pour off the supernatant, wash it by centrifugation three times, collect the precipitate and dry it to obtain the carbon-based carrier ZIF-8.

[0052] Weigh 2 g of ZIF-8 and dissolve it in 300 mL of methanol. Then weigh 0.09, 0.18, 0.26 and 0.44 mmol (1,1'-bis(diphenylphosphino)ferrocene) nickel dichloride and dissolve it in 200 mL of methanol. Then stir the two separately for 5 min and mix them by ultrasonic for 10 min. Stir vigorously at 40 ° C for 16 h. The solid phase product is collected by filtration, washed with methanol 5 times, and dried. Finally, the ground solid is placed in a tubular furnace and heated at a heating rate of 5 ° C / min under an argon flow rate (100 mL / min). It is heated to 950 ° C for 3 h and cooled to room temperature to obtain the diatomic catalyst ZIF-Fe-P-Ni with different ratios.

[0053] Add evenly ground ZIF-Fe-P-Ni to the water body contaminated by 4-CP, so that the concentration of ZIF-Fe-P-Ni in the reaction system is 0.1 g / L, and then add PMS, so that the concentration of PMS in the reaction system is 0.1 mM. Figure 6 As shown, all ratios of ZIF-Fe-P-Ni can achieve almost 100% removal of 4-CP within 4 min. Among them, the ZIF-Fe-P-Ni with the addition of 0.44 mmol (1,1'-bis(diphenylphosphino)ferrocene) nickel dichloride has the best effect, which can achieve 100% removal of 4-CP within 30 seconds.

[0054] Example 4

[0055] Weigh 12.75 g of Zn(NO3)6H2O and dissolve it in 1 L of pure water. Then weigh 29.15 g of 2-methylimidazole and dissolve it in 1 L of pure water. Stir the two for 5 min and mix them. Stir rapidly for 2 h and let stand for 12 h. Pour out the supernatant, wash with water by centrifugation 3 times, collect the precipitate and dry it to obtain the carbon-based carrier ZIF-8.

[0056] Weigh 2 g of ZIF-8 and dissolve it in 300 mL of methanol, then weigh 0.44 mmol (1,1'-bis(diphenylphosphino)ferrocene) nickel dichloride and dissolve it in 200 mL of methanol, then stir the two separately for 5 min and mix them by ultrasonic for 10 min, stir vigorously at 40 ° C for 16 h, collect the solid product by suction filtration, wash it with methanol 5 times, and dry it. Finally, put the evenly ground solid into a tube furnace, heat it at a heating rate of 5 ° C / min under an argon flow rate (100 mL / min), heat it to 950 ° C for 3 h, and cool it to room temperature to obtain the diatomic catalyst ZIF-Fe-P-Ni.

[0057] Evenly ground ZIF-Fe-P-Ni was added to the water body contaminated by 4-CP, so that the concentration of ZIF-Fe-P-Ni in the reaction system was 0.1 g / L, and then PMS was added, so that the concentration of PMS in the reaction system was 0.05, 0.1, 0.15, 0.2, and 0.4 mM, respectively. Figure 7 As shown in the figure, with the increase of PMS concentration, the removal effect of ZIF-Fe-P-Ni on 4-CP gradually increased, and the best effect was achieved when the PMS concentration was 0.4 mM. However, based on the cost saving considerations, 0.1 mM PMS was used.

[0058] Example 5

[0059] Weigh 12.75 g of Zn(NO3)6H2O and dissolve it in 1 L of pure water. Then weigh 29.15 g of 2-methylimidazole and dissolve it in 1 L of pure water. Stir the two for 5 min and mix them. Stir rapidly for 2 h and let stand for 12 h. Pour out the supernatant, wash with water by centrifugation 3 times, collect the precipitate and dry it to obtain the carbon-based carrier ZIF-8.

[0060] Weigh 2 g of ZIF-8 and dissolve it in 300 mL of methanol, then weigh 0.44 mmol (1,1'-bis(diphenylphosphino)ferrocene) nickel dichloride and dissolve it in 200 mL of methanol, then stir the two separately for 5 min and mix them by ultrasonic for 10 min, stir vigorously at 40 ° C for 16 h, collect the solid product by suction filtration, wash it with methanol 5 times, and dry it. Finally, put the evenly ground solid into a tube furnace, heat it at a heating rate of 5 ° C / min under an argon flow rate (100 mL / min), heat it to 950 ° C for 3 h, and cool it to room temperature to obtain the diatomic catalyst ZIF-Fe-P-Ni.

[0061] Evenly ground ZIF-Fe-P-Ni was added to the water body contaminated by 4-CP, and the concentrations of ZIF-Fe-P-Ni in the reaction system were 0.025, 0.05, 0.075, and 0.1 g / L, respectively. PMS was then added, and its concentration in the reaction system was 0.1 mM. Figure 8 As shown in the figure, with the increase of ZIF-Fe-P-Ni dosage, the removal effect of ZIF-Fe-P-Ni on 4-CP gradually increased, and the best effect was achieved when the ZIF-Fe-P-Ni dosage was 0.1 g / L.

[0062] Performance test

[0063] To further illustrate the effect of the present invention, X-ray diffraction (XRD) was performed on the catalyst of the present invention. Figure 1The XRD spectra of the catalyst samples ZIF, ZIF-Fe, ZIF-Fe-P, ZIF-Ni, ZIF-Fe-P-Ni, and ZIF-Fe-P-Co prepared in the above embodiment are shown. Figure 1 It can be seen that the diffraction peaks of the prepared ZIF-Fe, ZIF-Fe-P, ZIF-Fe-P-Ni, and ZIF-Fe-P-Co are the same as those of ZIF, and no peaks of Fe or Ni nanoparticles are detected, indicating that Fe and Ni exist in the form of single atoms.

[0064] Figure 2 Fourier transform infrared spectra (FTIR) were performed on the catalyst samples ZIF, ZIF-Fe, ZIF-Fe-P, ZIF-Ni, ZIF-Fe-P-Ni, and ZIF-Fe-P-Co described in the present invention. Figure 2 It can be seen that the diffraction peaks of the prepared ZIF-Fe, ZIF-Fe-P, ZIF-Ni, ZIF-Fe-P-Ni, and ZIF-Fe-P-Co are the same as those of ZIF, and no peaks of Fe or Ni nanoparticles are detected, indicating that Fe and Ni exist in the form of single atoms.

[0065] Figure 4 The figure shows the adsorption effect of 0.1 g / L single-atom and double-atom catalysts on 10 mg / L 4-CP without adding PMS. The adsorption effect of the catalyst on pollutants is about 20%. Figure 5 The figure shows the degradation of 4-CP by 0.1 g / L single and double atom catalysts. Among them, ZIF-Fe-P-Ni can achieve 100% removal of 4-CP in about 30 seconds. The degradation effect is very obvious, indicating that the oxidative degradation step accounts for the main contribution to the removal of aromatic organic pollutants, rather than a simple adsorption process that may cause secondary pollution to the environment.

[0066] In addition, compared with the existing aromatic organic pollutant removal technology, the technical method provided by this patent does not need to premix the catalyst and the pollutant for a long time in advance, but directly adds the diatomic catalyst and persulfate to the polluted water body, and can achieve 100% removal of aromatic pollutants in a short time; in the elimination mechanism of aromatic organic pollutants, the present invention uses a metal ligand compound containing P to react with ZIF-8 to obtain a diatomic catalyst containing non-metallic P heteroatom coordination, and the doping of non-metallic causes uneven distribution of electrons of transition metal atoms, which is more likely to cause electron migration and destroy the chemical structure of aromatic organic pollutants, thereby promoting catalytic oxidation degradation effect. Therefore, the diatomic material of the present invention can remove a variety of aromatic organic pollutants, such as quinolone antibiotics, sulfonamide antibiotics and phenolic compounds, and has a non-specific and efficient elimination effect on single organic pollutants.

[0067] Although the above-mentioned embodiment has made a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity. Equal changes and modifications made according to the scope of the patent application of the present invention should all fall within the scope of protection of the present invention.

Claims

1. A method for degrading aromatic organic pollutants in water by activating persulfate with a diatomic catalyst coordinated by a non-metallic heteroatom, characterized in that: The following steps are involved: (1) dissolving a carbon-based carrier ZIF-8 and a transition metal compound in methanol and mixing them for reaction, collecting the insoluble matter and calcining at high temperature to obtain a diatomic catalyst; the transition metal compound is (1,1'-bis(diphenylphosphino)ferrocene) chloride X, wherein X is one of Co and Ni; (2) Add diatomic catalysts and persulfate to the polluted water to oxidize and eliminate aromatic organic pollutants in the water.

2. The method for degrading aromatic organic pollutants in water by activating persulfate with a non-metallic heteroatom coordinated diatomic catalyst according to claim 1, characterized in that: The mass ratio of the carbon-based carrier ZIF-8 to the transition metal compound is 1:0.01-0.1; The mass ratio of the carbon-based carrier ZIF-8 to methanol is 1:10-500; The mass concentration / molar concentration of the diatomic catalyst and the persulfate is 0.01~1g / L: 0.1~1.0 mmol / L.

3. The method for degrading aromatic organic pollutants in water by activating persulfate with a non-metallic heteroatom coordinated diatomic catalyst according to claim 1, characterized in that: The calcination temperature is 800-1000°C and the calcination time is 2-5 h.

4. The method for degrading aromatic organic pollutants in water by activating persulfate with a non-metallic heteroatom coordinated diatomic catalyst according to claim 1, characterized in that: The persulfate is potassium permonosulfate PMS.

5. The method for degrading aromatic organic pollutants in water by activating persulfate with a non-metallic heteroatom coordinated diatomic catalyst according to claim 1, characterized in that: The diatomic catalyst is ZIF-Fe-P-Ni or ZIF-Fe-P-Co; the specific preparation method is as follows: 2 g of ZIF-8 was weighed and dissolved in 300 mL of methanol. Then 0.44 mmol of (1,1'-bis(diphenylphosphino)ferrocene) nickel dichloride or (1,1'-bis(diphenylphosphino)ferrocene) cobalt dichloride (II) was weighed and dissolved in 200 mL of methanol. The two were then stirred for 5 min and mixed by ultrasonic for 10 min. They were vigorously stirred at 40 °C for 16 h. The solid phase product was collected by filtration, washed with methanol 5 times, and dried. Finally, the evenly ground solid was placed in a tubular furnace and heated at a heating rate of 5 °C / min at an argon flow rate of 100 mL / min to 950 °C for 3 h. After cooling to room temperature, the diatomic catalyst ZIF-Fe-P-Ni or ZIF-Fe-P-Co was obtained.

6. The method for degrading aromatic organic pollutants in water by activating persulfate with a non-metallic heteroatom coordinated diatomic catalyst according to claim 1, characterized in that: The diatomic catalyst has an atomic dispersion effect and can achieve rapid degradation and removal of a variety of aromatic organic pollutants within 1 minute.

7. The method for degrading aromatic organic pollutants in water by activating persulfate with a non-metallic heteroatom coordinated diatomic catalyst according to claim 1, characterized in that: The method comprises the following steps: adding a diatomic catalyst into a water body containing organic pollutants, fully mixing and stirring, and then adding persulfate. The oxidant is activated by the diatomic catalyst to generate a large number of free radicals and non-free radicals, which attack and destroy the structure of aromatic organic pollutants to achieve the purpose of efficient degradation.

8. The method for degrading aromatic organic pollutants in water by activating persulfate with a non-metallic heteroatom coordinated diatomic catalyst according to claim 1, characterized in that: The pollutants include fluoroquinolone antibiotics, sulfonamide antibiotics, and para-chlorophenol organic pollutants.

9. The method for degrading aromatic organic pollutants in water by activating persulfate with a non-metallic heteroatom coordinated diatomic catalyst according to claim 5, characterized in that: Evenly ground ZIF-Fe-P-Ni was added to water bodies contaminated by SMX, NOR and 4-CP respectively, so that the concentration of ZIF-Fe-P-Ni in the reaction system was 0.1 g / L, and PMS was then added to make the concentration of PMS in the reaction system 0.1-0.4 mM. Stirring for 1 min can complete 100% removal of organic pollutants in SMX and 4-CP polluted water bodies, and stirring for 5 minutes can complete 100% removal of organic pollutants in NOR polluted water bodies.

Images