Method for synergistically degrading pfas by chlorophyll-cu derivative / h2o2 and application thereof

Abstract

The application relates to the technical field of pollutant treatment, and provides a method for degrading PFAS by chlorophyll-Cu derivatives / H2O2 and application thereof. The method for degrading PFAS provided by the application comprises the following steps: mixing a mixture containing chlorophyll-Cu derivatives and an H2O2 aqueous solution to obtain a mixture containing chlorophyll-Cu derivatives and H2O2; and mixing the mixture containing chlorophyll-Cu derivatives and H2O2 with a substance containing PFAS to make the PFAS degrade. The chlorophyll-Cu derivatives and H2O2 provided by the application can synergistically break the C-F bond in the PFAS, overcome the difficulty that the C-F bond is difficult to break in the prior art, and significantly improve the degradation efficiency of the PFAS.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pollutant treatment, in particular to a method for degrading PFAS by chlorophyll-Cu derivative / H2O2 synergistically and application thereof. BACKGROUND

[0002] Per- and Polyfluoroalkyl Substances (PFAS) are a class of synthetic organic fluorides, and their unique carbon-fluorine bond (C-F) and fluorinated carbon chain structure endow them with extremely high stability, but also lead to their persistence in the environment.

[0003] The high strength (bond energy ~485 kJ / mol) and low polarity of F bond make it one of the most difficult bonds to break in chemistry, which is the core reason why PFAS (perfluorinated compounds) are called "permanent chemicals". Therefore, it is also necessary to develop methods for degrading PFAS. SUMMARY

[0004] The purpose of the present application is to provide a method for degrading PFAS by chlorophyll-Cu derivative / H2O2 synergistically to improve the degradation rate of PFAS. The specific technical solutions are as follows:

[0005] The first aspect of the present application provides a method for degrading PFAS, which comprises: mixing a mixture containing chlorophyll-Cu derivative and an aqueous H2O2 solution to obtain a mixture containing chlorophyll-Cu derivative and H2O2; mixing the mixture containing chlorophyll-Cu derivative and H2O2 with a substance containing PFAS to cause degradation of PFAS.

[0006] In an embodiment of the present application, the concentration of H2O2 in the aqueous H2O2 solution is 273.2 g / L-303.55 g / L;

[0007] In the mixture containing chlorophyll-Cu derivative and H2O2, the concentration of chlorophyll-Cu derivative is 0.01 g / L-5 g / L, and the concentration of H2O2 is 5 mg / L-50 mg / L; the mass ratio of the substance containing PFAS to the mixture containing chlorophyll-Cu derivative and H2O2 is (1-5):1.

[0008] In an embodiment of the present application, in the mixture containing chlorophyll-Cu derivative and H2O2, the concentration of chlorophyll-Cu derivative is 0.1 g / L-0.3 g / L, and the concentration of H2O2 is 10 mg / L-30 mg / L;

[0009] The pH value of the mixture containing chlorophyll-Cu derivative is 2.0 to 7.0.

[0010] In an embodiment of the present application, the method further comprises the step of adding a persulfate salt to the mixture containing the chlorophyll-Cu derivative and H2O2;

[0011] The concentration of the persulfate salt in the mixture containing the chlorophyll-Cu derivative and H2O2 is 0.01 mol / L to 0.5 mol / L; the persulfate salt is selected from potassium persulfate or sodium persulfate.

[0012] In an embodiment of the present application, after the mixture containing the chlorophyll-Cu derivative and H2O2 is mixed with the substance containing PFAS, the method further comprises the step of treatment with a light source; the wavelength of the light source is 200 nm-2000 nm; the light source is treated at 50°C-80°C for 10 min-60 min;

[0013] The concentration of the chlorophyll-Cu derivative in the mixture containing the chlorophyll-Cu derivative and H2O2 is 0.05 g / L-5 g / L, and the concentration of H2O2 is 5 mg / L-50 mg / L.

[0014] In an embodiment of the present application, the method for preparing the mixture containing the chlorophyll-Cu derivative comprises: mixing chlorophyll a with a first organic solvent to obtain a first mixture, wherein the first organic solvent is selected from at least one of dichloromethane, methanol, ethanol, isopropanol, hexane and acetone;

[0015] The first mixture is mixed with an acid solution for demetalization to obtain a second mixture;

[0016] The second mixture is mixed with a copper salt solution and then subjected to microwave irradiation to obtain the mixture containing the chlorophyll-Cu derivative.

[0017] In an embodiment of the present application, the mass-volume ratio of chlorophyll a to the first organic solvent is 1 g:(10-50) mL;

[0018] The volume ratio of the first mixture to the acid solution is 1:(1-3); the acid solution is selected from an HCl solution with a concentration of 0.1 mol / L-1 mol / L, a sulfuric acid solution with a concentration of 0.05 mol / L-0.5 mol / L or an acetic acid solution with a concentration of 0.5 mol / L-2 mol / L;

[0019] The copper salt is selected from at least one of Cu(OAc)2, CuSO4, Cu(NO3)2 and CuCl2; the concentration of the copper salt solution is 0.01 mol / L-0.5 mol / L;

[0020] The volume ratio of the second mixture to the copper salt solution is 1:(0.5-2);

[0021] The microwave radiation has a radiation frequency of 1000-2500 MHz, a radiation temperature of 50-90℃, and a radiation time of 5-60 min.

[0022] In an embodiment of the present application, the microwave radiation is followed by the step of:

[0023] The mixture obtained after microwave radiation is mixed with biochar to allow the chlorophyll-Cu derivative to be fully adsorbed onto the surface of the biochar, and then solid-liquid separation is performed, and the solid is dried.

[0024] The mixture obtained after microwave radiation and the biochar have a mass ratio of 1:(0.1-1), and the drying temperature is -80-4℃.

[0025] In an embodiment of the present application, the method for preparing the mixture containing the chlorophyll-Cu derivative comprises: extracting a biomass raw material with a second organic solvent, collecting the liquid, and obtaining an extract containing chlorophyll a; wherein the biomass raw material comprises at least one of spirulina, spinach, and silkworm excrement; and the second organic solvent is selected from at least one of dichloromethane, methanol, ethanol, isopropanol, hexane, and acetone.

[0026] The extract containing chlorophyll a is mixed with a third organic solvent, and the liquid is collected to obtain a third mixture, wherein the third organic solvent is selected from a methanol solution containing 1-10 w / v% sodium hydroxide.

[0027] The third mixture is mixed with a copper salt solution and subjected to microwave radiation, and then filtered to remove solid impurities, to obtain a mixture containing a chlorophyll-Cu derivative.

[0028] In an embodiment of the present application, the mass ratio of the biomass raw material to the second organic solvent is 1:(3-20).

[0029] The volume ratio of the extract containing chlorophyll a to the third organic solvent is 1:(0.5-5).

[0030] The copper salt is selected from at least one of Cu(OAc)2, CuSO4, Cu(NO3)2, and CuCl2, and the concentration of the copper salt solution is 0.01-0.5 mol / L.

[0031] The mass ratio of the biomass raw material to the copper salt solution is 100:(1-10).

[0032] The microwave radiation has a radiation frequency of 1000-2500 MHz, a radiation temperature of 50-80℃, and a radiation time of 10-60 min.

[0033] The second aspect of the present application provides the use of the method of the first aspect of the present application in the purification treatment of PFAS-containing domestic water, the purification treatment of PFAS-containing sewage, or the remediation of PFAS-containing soil.

[0034] Advantages of the present application:

[0035] The present application provides a PFAS degradation method. The synergistic effect of chlorophyll-Cu derivative and H2O2 can efficiently break the C-F bond in PFAS, overcoming the difficulty of breaking the C-F bond in the prior art, and significantly improving the degradation efficiency of PFAS. Chlorophyll-Cu derivative has light absorption characteristics, and synergizes with H2O2 to generate various active free radicals, attack the C-F bond at different sites of the PFAS molecule, break the PFAS structure, and obtain short-chain PFAS molecules; the cyclic electron transfer process makes the functional groups in the PFAS molecule unstable, promotes the decomposition of PFAS, and catalyzes chlorophyll-Cu derivative to adsorb PFAS molecules to its surface through coordination, thereby increasing the local concentration of the reaction and being beneficial to the degradation of PFAS.

[0036] Of course, implementing any product or method of the present application does not necessarily require achieving all the advantages described above at the same time. DETAILED DESCRIPTION

[0037] The technical solutions in the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. All other embodiments obtained by those skilled in the art based on the present application are within the scope of protection of the present application.

[0038] The first aspect of the present application provides a method for degrading PFAS, comprising: mixing a mixture containing chlorophyll-Cu derivative and an aqueous solution of H2O2 to obtain a mixture containing chlorophyll-Cu derivative and H2O2; mixing the mixture containing chlorophyll-Cu derivative and H2O2 with a substance containing PFAS to make PFAS degrade.

[0039] Coordination between oxidizing agent and metal ion, Cu in chlorophyll-Cu derivative 2+ Can be used as an electron mediator to promote oxidative decomposition to produce active species, decompose active free radicals in the reaction process, produce, for example, ·OH, O2· -The oxidizing agent can provide a continuous oxygen source and reduce the activation energy of the reaction, and PFAS can be degraded under dark conditions. The various active radicals generated together attack the C-F bonds at different positions of the PFAS molecule, break the PFAS structure, obtain short-chain PFAS molecules, improve the mineralization rate, and avoid the accumulation of intermediate products caused by a single active radical, which is conducive to making the mineralization of PFAS more complete. The mineralization rate is a key indicator for measuring the degree of decomposition of PFAS.

[0040] The chlorophyll-Cu derivative has light absorption characteristics. Under light conditions, the electrons in the molecule can be excited to a higher energy level to form an excited state. The excited state of the chlorophyll-Cu derivative has strong redox ability and can convert the absorbed light energy into chemical energy to generate ROS, such as hydroxyl radicals (·OH), superoxide anion radicals (·O2 - ), and the like. These ROS have strong oxidizing properties and can attack PFAS molecules to cause chemical bond rupture and degradation. For example, ·OH can directly attack the C-F bond, C-C bond, and the like in the PFAS molecule, causing the PFAS molecule to gradually decompose into smaller fragments.

[0041] In the process of degrading PFAS, the central copper ion of the chlorophyll-Cu derivative plays a role in electron transfer. Cu 2+ accepts electrons and is reduced to Cu + , and then Cu + transfers electrons to other substances while being oxidized back to Cu 2+ , forming a cyclic electron transfer process. In the cycle, short-chain PFAS molecules can act as electron acceptors and accept electrons from the chlorophyll-Cu derivative, causing oxidation. This cyclic electron transfer process causes the functional groups in the PFAS molecule to change, making it unstable and decomposing.

[0042] In the process of degrading PFAS, the porphyrin ring structure of the chlorophyll-Cu derivative also coordinates with short-chain PFAS molecules. Through this coordination, PFAS molecules are adsorbed to the surface of the chlorophyll-Cu derivative, enriching PFAS molecules on the catalyst surface and increasing the local concentration of the reaction, which is conducive to the oxidation degradation of PFAS; and the coordination may also cause the structure of the PFAS molecule to be twisted and deformed to some extent, making its chemical bonds more easily attacked and broken, thereby promoting the oxidation degradation of PFAS.

[0043] In summary, the synergistic effect of chlorophyll-Cu derivative and H2O2 can efficiently break the C-F bond in PFAS, overcoming the difficulty of breaking the C-F bond in the prior art, and significantly improving the degradation efficiency of PFAS. Chlorophyll-Cu derivative has light absorption characteristics, and can produce various active free radicals in cooperation with H2O2, attack the C-F bond at different sites of PFAS molecule, break the PFAS structure, and obtain short-chain PFAS molecules; the cyclic electron transfer process makes the functional groups in the PFAS molecule unstable, promotes the decomposition of PFAS, and catalyzes chlorophyll-Cu derivative to adsorb PFAS molecules to its surface through coordination, thereby improving the local concentration of the reaction and being beneficial to the degradation of PFAS.

[0044] In an embodiment of the present application, the concentration of H2O2 in the aqueous H2O2 solution is 273.2 g / L to 303.55 g / L; the concentration of chlorophyll-Cu derivative in the mixture containing chlorophyll-Cu derivative and H2O2 is 0.01 g / L to 5 g / L, and the concentration of H2O2 is 5 mg / L to 50 mg / L; and the mass ratio of the substance containing PFAS to the mixture containing chlorophyll-Cu derivative and H2O2 is (1-5):1. For example, the concentration of H2O2 in the aqueous H2O2 solution can be 273.2 g / L, 275 g / L, 278 g / L, 280 g / L, 282 g / L, 285 g / L, 288 g / L, 290 g / L, 292 g / L, 295 g / L, 298 g / L, 300 g / L, 303.55 g / L, or a range between any two of the above values; the concentration of chlorophyll-Cu derivative in the mixture containing chlorophyll-Cu derivative and H2O2 can be 0.01 g / L, 0.1 g / L, 0.5 g / L, 1 g / L, 2 g / L, 3 g / L, 4 g / L, 5 g / L, or a range between any two of the above values; the concentration of H2O2 can be 5 mg / L, 10 mg / L, 15 mg / L, 20 mg / L, 25 mg / L, 30 mg / L, 35 mg / L, 40 mg / L, 45 mg / L, 50 mg / L, or a range between any two of the above values; and the mass ratio of the substance containing PFAS to the mixture containing chlorophyll-Cu derivative and H2O2 can be 1:1, 2:1, 3:1, 4:1, 5:1, or a range between any two of the above ratios.

[0045] In one embodiment of the present application, the method for degrading PFAS further comprises the step of adding persulfate to the mixture containing chlorophyll-Cu derivative and H2O2; the concentration of persulfate in the mixture containing chlorophyll-Cu derivative and H2O2 is 0.01 mol / L-0.5 mol / L; the persulfate is selected from potassium persulfate (K2S2O8) or sodium persulfate (Na2S2O8). For example, the concentration of persulfate can be 0.01 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L or a range between any two of the values. H2O2, persulfate and metal ion Cu 2+ react with each other, Cu 2+ in chlorophyll-Cu derivative can act as an electron mediator to promote the decomposition of oxidant H2O2 to generate active species, Cu 2+ react with persulfate to generate Cu + and SO4· - Cu + is oxidized to Cu 2+ again by O2 to form a cycle, and the generated superoxide radical (O2· - ) and SO4· - can gradually attack PFAS molecules to make them defluorinate and degrade; and in the process of electron transfer in the cycle, short-chain PFAS molecules are continuously oxidized, so that the functional groups of PFAS molecules become unstable, thereby promoting the decomposition of PFAS.

[0046] In one embodiment of the present application, after the mixture containing the chlorophyll-Cu derivative and H2O2 is mixed with the substance containing PFAS, a step of treatment with a light source is further included; the wavelength of the light source is 200 nm-2000 nm; the treatment time of the light source at 50-80°C is 10-60 min; the concentration of the chlorophyll-Cu derivative in the mixture containing the chlorophyll-Cu derivative and H2O2 is 0.05-5 g / L, and the concentration of H2O2 is 5-50 mg / L. For example, the wavelength of the light source can be 200 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 900 nm, 1100 nm, 1300 nm, 1500 nm, 1700 nm, 1900 nm, 2000 nm, or a range between any two of the above values; the treatment temperature of the light source can be 50°C, 60°C, 70°C, 80°C, or a range between any two of the above values; the treatment time of the light source can be 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, or a range between any two of the above values; the concentration of the chlorophyll-Cu derivative can be 0.05 g / L, 0.1 g / L, 0.15 g / L, 0.2 g / L, 0.3 g / L, 0.4 g / L, 0.5 g / L, 1 g / L, 1.5 g / L, 2 g / L, 2.5 g / L, 3 g / L, 3.5 g / L, 4 g / L, 4.5 g / L, 5 g / L, or a range between any two of the above values; the concentration of H2O2 can be 5 mg / L, 5.5 mg / L, 6 mg / L, 6.5 mg / L, 7 mg / L, 7.5 mg / L, 8 mg / L, 8.5 mg / L, 9 mg / L, 9.5 mg / L, 10 mg / L, 15 mg / L, 20 mg / L, 25 mg / L, 30 mg / L, 35 mg / L, 40 mg / L, 45 mg / L, 50 mg / L, or a range between any two of the above values. The chlorophyll-Cu derivative has light absorption properties, and under the light source irradiation conditions of the present application, the light absorption of the chlorophyll-Cu derivative is stronger. Because of the absorption peak of infrared and the near-infrared absorption ability, the utilization efficiency of long-wave light (such as red light and near-infrared light) in sunlight is higher, and the electrons in the chlorophyll-Cu derivative molecule can be excited to a higher energy level to form an excited state. The excited state of the chlorophyll-Cu derivative has strong redox ability and higher catalytic activity, and can convert the absorbed light energy into chemical energy in a wider spectrum range, catalyzing the oxidation to produce reactive oxygen species such as hydroxyl radicals (·OH), superoxide anion radicals (·O2 -) and the like. These active oxygen species have strong oxidizing properties and can attack PFAS molecules, causing bond breakage and degradation. For example, ·OH can directly attack C-F bonds, C-C bonds, and the like in PFAS molecules, causing the PFAS molecules to gradually decompose into smaller fragments; under the light source irradiation conditions of the present application, the structure of the chlorophyll-Cu derivative can also be stabilized (avoiding reduction and degradation of the porphyrin ring). Furthermore, under the photocatalytic system, the electron transfer efficiency is improved through the light-driven reaction mechanism, the C-F bond breakage is accelerated, the dependence on acidic conditions in the traditional Fenton system is broken through, and the degradation efficiency of PFAS is improved.

[0047] In an embodiment of the present application, the wavelength of the light source is 400-700 nm. For example, the wavelength of the light source can be 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, or a range between any two of the values.

[0048] In an embodiment of the present application, under the photocatalytic system, the concentration of the chlorophyll-Cu derivative in the mixture containing the chlorophyll-Cu derivative and H2O2 is 0.05-0.2 g / L, and the concentration of H2O2 is 5-10 mg / L. By adjusting the concentrations of the chlorophyll-Cu derivative and H2O2 within the ranges of the present application, the chlorophyll-Cu derivative and H2O2 have a synergistic effect on the degradation of PFAS, and the cost of degrading PFAS is relatively low.

[0049] In an embodiment of the present application, under the photocatalytic system, the method further comprises the step of adding persulfate to the mixture containing the chlorophyll-Cu derivative and H2O2; the concentration of the persulfate in the mixture containing the chlorophyll-Cu derivative and H2O2 is 0.01-0.5 mol / L. For example, the concentration of the persulfate can be 0.01 mol / L, 0.1 mol / L, 0.15 mol / L, 0.2 mol / L, 0.25 mol / L, 0.3 mol / L, 0.35 mol / L, 0.4 mol / L, 0.45 mol / L, 0.5 mol / L, or a range between any two of the values.

[0050] In an embodiment of the present application, under the photocatalytic system, the pH of the mixture containing the chlorophyll-Cu derivative is not particularly limited, as long as it meets the purpose of the present application.

[0051] In one embodiment of the present application, in the mixture containing chlorophyll-Cu derivative and H2O2 under non-photocatalytic system, the concentration of chlorophyll-Cu derivative is 0.1 g / L-0.3 g / L, the concentration of H2O2 is 10 mg / L-30 mg / L; the pH value of the mixture containing chlorophyll-Cu derivative is 2.0-7.0. For example, in the mixture containing chlorophyll-Cu derivative and H2O2, the concentration of chlorophyll-Cu derivative can be 0.1 g / L, 0.15 g / L, 0.2 g / L, 0.25 g / L, 0.3 g / L or a range between any two of them; the concentration of H2O2 can be 10 mg / L, 15 mg / L, 20 mg / L, 25 mg / L, 30 mg / L or a range between any two of them; the pH value can be 2.0, 3.0, 4.0, 5.0, 6.0, 7.0 or a range between any two of them. Under non-photocatalytic system, it needs to rely on the oxidation ability of oxidant H2O2 itself, and chlorophyll-Cu derivative produces active species such as ·OH, O2· - and other active free radicals, and oxidant H2O2 can provide a continuous oxygen source and reduce the reaction activation energy, which can degrade PFAS under dark conditions. The generated active free radicals work together to attack the C-F bond at different sites of PFAS molecules, break the PFAS structure, and the central copper ion of chlorophyll-Cu derivative plays a role in electron transfer in the process of oxidative degradation. Cu 2+ accepts electrons and is reduced to Cu + , then Cu + transfers electrons to other substances while being oxidized back to Cu 2+, forming a cyclic electron transfer process. In the cycle, the short-chain PFAS molecules can act as electron acceptors, accepting electrons from the chlorophyll-Cu derivatives, and undergoing oxidation. This electron transfer process can cause changes in the functional groups of the PFAS molecules, making them unstable and decomposing; in the process of degrading PFAS, the porphyrin ring structure of the chlorophyll-Cu derivative can also coordinate with the short-chain PFAS molecules. Through this coordination, the PFAS molecules are adsorbed to the surface of the chlorophyll-Cu derivative, enriching the PFAS molecules on the surface of the catalyst and increasing the local concentration of the reaction, which is conducive to the oxidation degradation of PFAS; and the coordination may also cause the structure of the PFAS molecules to be twisted and deformed to some extent, making their chemical bonds more easily attacked and broken, thereby promoting the oxidation degradation of PFAS; when the mixture containing the chlorophyll-Cu derivative is used to degrade PFAS in a non-photocatalytic system, it needs to be carried out under acidic or neutral conditions. Therefore, the concentration of chlorophyll-Cu derivative, the concentration of H2O2, and the pH are within the scope of the present application, and the use amount of chlorophyll-Cu derivative and H2O2 in the reaction is matched, which improves the degradation rate of PFAS.

[0052] In an embodiment of the present application, in a non-photocatalytic system, the method further comprises the step of adding persulfate to the mixture containing chlorophyll-Cu derivative and H2O2; the concentration of persulfate in the mixture containing chlorophyll-Cu derivative and H2O2 is 0.01 mol / L to 0.5 mol / L. For example, the concentration of persulfate can be 0.01 mol / L, 0.1 mol / L, 0.15 mol / L, 0.25 mol / L, 0.3 mol / L, 0.35 mol / L, 0.4 mol / L, 0.5 mol / L, or a range between any two of the above values.

[0053] In the present application, the way to regulate the pH value of the mixture containing chlorophyll-Cu derivative is not particularly limited, as long as it can meet the purpose of the present application. For example, the pH value can be regulated by adding a second acid solution and / or a base solution, the second acid solution is selected from HCl solution with a concentration of 0.1 mol / L to 1 mol / L, and the base solution is selected from Na2CO3 solution with a concentration of 0.1 mol / L to 1 mol / L.

[0054] In an embodiment of the present application, the method for preparing the mixture containing the chlorophyll-Cu derivative comprises: mixing chlorophyll a with a first organic solvent to obtain a first mixture, wherein the first organic solvent is selected from at least one of dichloromethane, methanol, ethanol, isopropanol, hexane and acetone; performing demetalation by mixing the first mixture with an acid solution, to obtain a second mixture, wherein the acid solution is referred to as a first acid solution; and performing microwave irradiation after mixing the second mixture with a copper salt solution, to obtain the mixture containing the chlorophyll-Cu derivative. The mixture containing the chlorophyll-Cu derivative prepared from biomass resources is used as a catalytic material, which can significantly reduce the preparation cost, realize the recycling of resources, meet the development concept of green chemistry, and further simplify the preparation process, improve the production efficiency, and make the preparation method more environmentally friendly, efficient and safe by combining the microwave-assisted green synthesis process.

[0055] In an embodiment of the present application, the mass-volume ratio of chlorophyll a to the first organic solvent is 1 g:(10-50) mL. For example, the mass-volume ratio of chlorophyll a to the first organic solvent can be 1 g:10 mL, 1 g:20 mL, 1 g:30 mL, 1 g:40 mL, 1 g:50 mL, or a range formed between any two of them.

[0056] In an embodiment of the present application, the volume ratio of the first mixture to the first acid solution is 1:(1-3); and the first acid solution is selected from an HCl solution with a concentration of 0.1 mol / L-1 mol / L, a sulfuric acid solution with a concentration of 0.05 mol / L-0.5 mol / L, or an acetic acid solution with a concentration of 0.5 mol / L-2 mol / L. For example, the volume ratio of the first mixture to the first acid solution can be 1:1, 1:2, 1:3, or a range formed between any two of them.

[0057] In an embodiment of the present application, the copper salt is selected from at least one of Cu(OAc)2, CuSO4, Cu(NO3)2 and CuCl2; and the concentration of the copper salt solution is 0.01 mol / L-0.5 mol / L. For example, the concentration of the copper salt solution can be 0.01 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, or a range formed between any two of them.

[0058] In an embodiment of the present application, the volume ratio of the second mixture to the copper salt solution is 1:(0.5-2). For example, the volume ratio of the second mixture to the copper salt solution can be 1:0.5, 1:1, 1:1.5, 1:2, or a range formed between any two of them.

[0059] In an embodiment of the present application, the microwave irradiation has a radiation frequency of 1000-2500 MHz, a radiation temperature of 50-90°C, and a radiation time of 5-60 min. In an embodiment of the present application, the radiation temperature is 60-80°C, and the radiation time is 10-20 min. For example, the microwave irradiation can have a radiation frequency of 1000, 1200, 1400, 1600, 1800, 2000, 2200, 2400, 2420, 2440, 2460, 2480, 2500 MHz, or a range between any two of the values. The radiation temperature can be 50, 60, 65, 70, 75, 80, 90°C, or a range between any two of the values. The radiation time can be 5, 10, 12, 14, 16, 18, 20, 30, 40, 50, 60 min, or a range between any two of the values.

[0060] In an embodiment of the present application, after the microwave irradiation, the mixture obtained after the microwave irradiation is mixed with biochar, and the mixture is stirred or shaken to allow the chlorophyll-Cu derivative to be fully adsorbed onto the surface of the biochar. Then, the solid-liquid separation is performed, and the solid is dried. In this embodiment, the mass ratio of the mixture obtained after the microwave irradiation to the biochar is 1: (0.1-1), and the drying temperature is -80-4°C. For example, the mass ratio of the mixture obtained after the microwave irradiation to the biochar can be 1:0.1, 1:0.2, 1:0.4, 1:0.6, 1:0.8, 1:1, or a range between any two of the ratios. The drying temperature can be -80, -60, -40, -20, -10, 0, 4°C, or a range between any two of the values. The mixture containing the chlorophyll-Cu derivative obtained in this way can be used in the process of degrading PFAS, and the solar-driven in-situ remediation can be performed. The chlorophyll-Cu derivative has light absorption properties, and under light conditions, the electrons in the molecule can be excited to a higher energy level to form an excited state. The chlorophyll-Cu derivative in the excited state has strong redox ability, and can convert the absorbed light energy into chemical energy to generate ROS, such as hydroxyl radicals (·OH), superoxide anion radicals (·O2 - ), and the like. These ROS have strong oxidizing properties, and can attack PFAS molecules to cause the chemical bonds to break and degrade. For example, ·OH can directly attack the C-F bond, C-C bond, and the like in the PFAS molecule to gradually decompose the PFAS molecule into smaller fragments.

[0061] The central copper ion of the chlorophyll-Cu derivative plays a role in electron transfer, and Cu 2+accepting an electron to be reduced to Cu + , the Cu + transfers the electron to another substance, while itself being oxidized back to Cu 2+ , forming a cyclic electron transfer process. In the cyclic process, the short-chain PFAS molecule can act as an electron acceptor, accepting an electron from the chlorophyll-Cu derivative, and undergoing an oxidation reaction. This cyclic electron transfer process can cause changes in the functional groups of the PFAS molecule, making it unstable and thus decomposing. Solar-driven can improve the efficiency of electron transfer, Cu 2+ promotes the generation of singlet oxygen ( 1 O2), accelerates the breaking of C-F bonds, oxidizes and cleaves the polar head of the PFAS molecule, promotes the decomposition of PFAS, and improves the degradation rate of PFAS.

[0062] In the mixture containing the chlorophyll-Cu derivative, the carrier is biochar, which can adsorb PFAS to the vicinity of the reaction site, shorten the reaction distance, increase the collision probability of active radicals and PFAS, and improve the degradation rate of PFAS.

[0063] In the process of degrading PFAS, the porphyrin ring structure of the chlorophyll-Cu derivative can also coordinate with the short-chain PFAS molecule. Through this coordination, the PFAS molecule is adsorbed to the surface of the chlorophyll-Cu derivative, enriching the PFAS molecule on the surface of the catalyst and increasing the local concentration of the reaction, which is conducive to the oxidation degradation of PFAS; and the coordination can also cause the structure of the PFAS molecule to be twisted and deformed to some extent, making its chemical bonds more easily attacked and broken, thereby promoting the oxidation degradation of PFAS.

[0064] In this application, the solid-liquid separation and drying step after the chlorophyll-Cu derivative is adsorbed to the surface of the biochar is not particularly limited, as long as it can achieve the purpose of the application. For example, the solid-liquid separation and drying step can be: separating the solid from the solution by filtration, centrifugation, etc., and then drying the separated solid at -80℃-4℃. Specifically, the drying step can be: separating the solid from the solution by filtration, and then drying the solid in a vacuum drying oven at 0℃ to obtain a mixture containing the chlorophyll-Cu derivative.

[0065] In this application, the temperature, intensity and time of stirring and oscillation are not particularly limited, as long as they can achieve the purpose of the application. For example, the intensity of stirring can be 100-300 rpm, the time of stirring can be 1-2 h, and the temperature of stirring can be room temperature; the intensity of oscillation can be 100-200 rpm, the time of oscillation can be 1.5-3 h, and the temperature of oscillation can be room temperature.

[0066] In the present application, the source of chlorophyll a (CAS No.: 479-61-8) is not particularly limited as long as the purpose of the present application can be achieved. For example, chlorophyll a can be obtained by market purchase or prepared by conventional methods in the art.

[0067] In an embodiment of the present application, the preparation method of the mixture containing chlorophyll-Cu derivatives comprises: extracting the biomass raw material with a second organic solvent, collecting the liquid to obtain an extract containing chlorophyll a; wherein the biomass raw material comprises at least one of spirulina, spinach and silkworm excrement; the second organic solvent is selected from at least one of dichloromethane, methanol, ethanol, isopropanol, hexane and acetone;

[0068] Mixing the extract containing chlorophyll a with a third organic solvent, collecting the liquid to obtain a third mixture, wherein the third organic solvent is selected from a methanol solution containing 1w / v%-10w / v% sodium hydroxide;

[0069] After mixing the third mixture with a copper salt solution and performing microwave irradiation, filtering to remove solid impurities to obtain a mixture containing chlorophyll-Cu derivatives (denoted as a fourth mixture). The present application uses biomass resources to prepare a mixture containing chlorophyll-Cu derivatives as a catalytic material, which can significantly reduce the preparation cost, realize the recycling of resources, meet the development concept of green chemistry, and further simplify the preparation process, improve the production efficiency, and make the preparation method more environmentally friendly, efficient and safe by combining the microwave-assisted green synthesis process.

[0070] In the present application, the filtration method is not particularly limited as long as the purpose of the present application can be achieved. For example, it can be plate and frame filtration, centrifugal filtration.

[0071] In an embodiment of the present application, the mass ratio of the biomass raw material to the second organic solvent is 1:(3-20). For example, the mass ratio of the biomass raw material to the second organic solvent can be 1:3, 1:5, 1:10, 1:15, 1:20 or a range composed between any two of them.

[0072] In an embodiment of the present application, the volume ratio of the extract containing chlorophyll a to the third organic solvent is 1:(0.5-5). For example, the volume ratio of the extract containing chlorophyll a to the third organic solvent can be 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5 or a range composed between any two of them.

[0073] In one embodiment of the present application, the copper salt is selected from at least one of Cu(OAc)2, CuSO4, Cu(NO3)2and CuCl2; the concentration of the copper salt solution is 0.01 mol / L-0.5 mol / L. For example, the concentration of the copper salt solution can be 0.01 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L or a range between any two of the values.

[0074] In one embodiment of the present application, the mass ratio of the biomass raw material to the copper salt solution is 100: (1-10). For example, the mass ratio of the biomass raw material to the copper salt solution can be 100:1, 100:2, 100:4, 100:6, 100:8, 100:10 or a range between any two of the ratios.

[0075] In one embodiment of the present application, the radiation frequency of the microwave radiation is 1000 MHz-2500 MHz, the radiation temperature is 50℃-80℃, and the radiation time is 10 min-60 min. For example, the radiation frequency of the microwave radiation can be 1000 MHz, 1200 MHz, 1400 MHz, 1600 MHz, 1800 MHz, 2000 MHz, 2200 MHz, 2400 MHz, 2420 MHz, 2440 MHz, 2460 MHz, 2480 MHz, 2500 MHz or a range between any two of the values; the radiation temperature can be 50℃, 60℃, 70℃, 80℃ or a range between any two of the values; and the radiation time can be 10 min, 20 min, 30 min, 40 min, 50 min, 60 min or a range between any two of the values.

[0076] In the present application, the method for crystallizing the chlorophyll-Cu derivative using the fourth mixture is not particularly limited as long as the purpose of the present application can be achieved. For example, the method for crystallizing the chlorophyll-Cu derivative can be acidification crystallization, specifically:

[0077] (I) The fourth mixture is slowly added to the third acid solution under stirring to avoid excessive local acidity leading to crystal agglomeration or decomposition; the pH value is monitored in real time during the acidification process, and the pH value is adjusted to an acidic range of 1-4; in one embodiment of the present application, the pH value can be adjusted to an acidic range of 1-2, and the adjustment of the pH value is performed at a temperature of 10℃-40℃; wherein the third acid solution is selected from a hydrochloric acid solution with a concentration of 0.1 mol / L to 1 mol / L, a sulfuric acid solution with a concentration of 0.05 mol / L to 0.5 mol / L or an acetic acid solution with a concentration of 0.5 mol / L to 2 mol / L.

[0078] (II) When the pH value decreases to the target range, the solid chlorophyll-Cu derivative gradually precipitates from the solution to form crystals, and the aging time is 5-24 h; for example, the aging time can be 5 h, 8 h, 10 h, 12 h, 15 h, 18 h, 20 h, 22 h, 24 h, or a range formed by any two of the above values;

[0079] (III) The crystallized crystals are washed with cold methanol at a temperature of ≤4℃ for 2-3 times to remove residual salts and impurities, and then dried at 20℃-60℃ under vacuum.

[0080] In the present application, the solubility of chlorophyll-Cu derivative is low at low temperature of 10℃-40℃ during acidification, and reducing temperature helps to improve the precipitation rate and purity of chlorophyll-Cu derivative.

[0081] The second aspect of the present application provides the use of the method of the first aspect of the present application in the purification treatment of PFAS-containing domestic water, the purification treatment of PFAS-containing sewage, or the remediation of PFAS-containing soil.

[0082] In an embodiment of the present application, the purification treatment of PFAS-containing sewage includes the purification treatment of sewage containing fire-fighting foam.

[0083] The present application provides an efficient, low-consumption, and environmentally friendly full-chain solution for PFAS pollution treatment, broadens the application range, and makes a positive contribution to environmental protection.

[0084] Examples

[0085] Hereinafter, examples and comparative examples are given to more specifically illustrate the embodiments of the present application. Various tests and evaluations are carried out according to the following methods. In addition, unless otherwise specified, "parts" and "%" are based on mass.

[0086] PFAS degradation rate test:

[0087] The test is performed by high performance liquid chromatography-mass spectrometry (HPLC-MS), and the specific steps refer to "Determination of Perfluorooctylsulfonic Acid and Perfluorooctanoic Acid and Their Salts by Isotope Dilution / Liquid Chromatography-Triple Quadrupole Mass Spectrometry" (HJ 1333-2023) and "Determination of Perfluorooctylsulfonic Acid and Perfluorooctanoic Acid and Their Salts in Soil and Sediment by Isotope Dilution / Liquid Chromatography-Triple Quadrupole Mass Spectrometry" (HJ 1334-2023).

[0088] The PFAS degradation rate (%) = (the PFAS content (mg) in the PFAS-containing substance before adding the mixture containing the chlorophyll-Cu derivative and H2O2 - the PFAS content (mg) after adding the mixture containing the chlorophyll-Cu derivative and H2O2) / the PFAS content (mg) in the PFAS-containing substance before adding the mixture containing the chlorophyll-Cu derivative H2O2 x 100%.

[0089] Example 1

[0090] 1. Preparation of a mixture containing a chlorophyll-Cu derivative:

[0091] S11: chlorophyll a is mixed with a first organic solvent methanol to obtain a first mixture; wherein the mass-volume ratio of chlorophyll a to methanol is 1 g: 20 mL;

[0092] S12: the first mixture is mixed with an HCl solution for demetallization to obtain a second mixture; wherein the concentration of the HCl solution is 0.5 mol / L; the volume ratio of the first mixture to the HCl solution is 1:2;

[0093] S13: the second mixture is mixed with a copper salt solution and then subjected to microwave irradiation, the irradiation frequency is 2450 MHz, the irradiation temperature is 80°C, and the irradiation time is 10 min to obtain a mixture containing a chlorophyll-Cu derivative; wherein the copper salt solution is selected from a CuSO4 solution with a concentration of 0.25 mol / L, and the volume ratio of the second mixture to the copper salt solution is 1:1.

[0094] 2. The specific method for degrading PFAS by using the mixture containing the chlorophyll-Cu derivative is:

[0095] S21: the mixture containing the chlorophyll-Cu derivative prepared in S13 is mixed with an H2O2 solution with a concentration of 303.55 g / L (i.e. the concentration of the H2O2 solution is 100 vol%) to obtain a mixture containing the chlorophyll-Cu derivative and H2O2, wherein the concentration of the chlorophyll-Cu derivative in the mixture containing the chlorophyll-Cu derivative and H2O2 is 0.1 g / L, and the concentration of H2O2 is 7.5 mg / L;

[0096] S22: the mixture containing the chlorophyll-Cu derivative and H2O2 is mixed with sewage containing PFAS, and then irradiated under a 550 nm light source for 20 min to degrade PFAS; wherein the mass ratio of the sewage containing PFAS (the concentration of PFAS is 7.5 mg / L, and the volume is 10 L) to the mixture containing the chlorophyll-Cu derivative and H2O2 is 3:1.

[0097] Examples 2 to 7

[0098] The rest is the same as Example 1 except that the related parameters are adjusted according to Table 1. Among them, by adjusting the volume of the mixture containing the chlorophyll-Cu derivative added, the concentration of the chlorophyll-Cu derivative in the mixture containing the chlorophyll-Cu derivative and H2O2 is adjusted; by adjusting the volume of the H2O2 solution added, the concentration of H2O2 is adjusted.

[0099] Example 8

[0100] 1. Preparation of a mixture containing a chlorophyll-Cu derivative:

[0101] S11: Mix chlorophyll a with the first organic solvent methanol to obtain a first mixture; wherein the mass-volume ratio of chlorophyll a to methanol is 1 g:20 mL;

[0102] S12: Mix the first mixture with an HCl solution for demetallization to obtain a second mixture; wherein the concentration of the HCl solution is 0.5 mol / L; the volume ratio of the first mixture to the HCl solution is 1:2;

[0103] S13: Mix the second mixture with a copper salt solution and then perform microwave irradiation, the irradiation frequency is 2450 MHz, the irradiation temperature is 80°C, and the irradiation time is 10 min to obtain a mixture containing a chlorophyll-Cu derivative; wherein the copper salt solution is selected from a Cu(OAc)2 solution with a concentration of 0.25 mol / L, and the volume ratio of the second mixture to the copper salt solution is 1:1.

[0104] 2. The specific method for degrading PFAS using the mixture containing the chlorophyll-Cu derivative is:

[0105] S21: Mix the mixture containing the chlorophyll-Cu derivative prepared in S13, an H2O2 solution with a concentration of 303.55 g / L, and a K2S2O8 solution to obtain a mixture containing chlorophyll-Cu derivative and H2O2, wherein the concentration of chlorophyll-Cu derivative in the mixture containing chlorophyll-Cu derivative and H2O2 is 0.1 g / L, the concentration of H2O2 is 7.5 mg / L, and the concentration of K2S2O8 is 0.3 mol / L;

[0106] S22: Mix the mixture containing chlorophyll-Cu derivative and H2O2 with wastewater containing PFAS (the concentration of PFAS is 7.5 mg / L, and the volume is 10 L), and then irradiate under a 550 nm light source for 20 min to degrade PFAS; wherein the mass ratio of the substance containing PFAS to the mixture containing chlorophyll-Cu derivative and H2O2 is 3:1.

[0107] Example 9

[0108] The rest is the same as Example 1 except that the "preparation of a mixture containing chlorophyll-Cu derivatives" is prepared according to the following method.

[0109] 1. Preparation of a mixture containing chlorophyll-Cu derivatives

[0110] S11: The biomass raw material spinach is soaked with the second organic solvent methanol, and the soaking liquid is collected to obtain an extract containing chlorophyll a; wherein the mass ratio of spinach to methanol is 1:10;

[0111] S12: The extract containing chlorophyll a is mixed with a third organic solvent 5w / v% sodium hydroxide methanol solution (solvent is methanol) to obtain a third mixture; wherein the volume ratio of the extract containing chlorophyll a to the third organic solvent is 1:3;

[0112] S13: The third mixture is mixed with a copper salt solution and then subjected to microwave irradiation, the irradiation frequency of microwave irradiation is 2450MHz, the irradiation temperature is 80°C, and the irradiation time is 10min, and then the solid impurities are removed by filtration to obtain a mixture containing chlorophyll-Cu derivatives; wherein the copper salt solution is selected from a CuSO4 solution with a concentration of 0.25mol / L, and the mass ratio of the biomass raw material to the copper salt solution is 100:5.

[0113] Example 10

[0114] 1. Preparation of a mixture containing chlorophyll-Cu derivatives:

[0115] S11: The mixture obtained after microwave irradiation prepared in step S13 of Example 1 and biochar are mixed according to a mass ratio of 1:0.5, stirred at room temperature at 200rpm for 1.5h to allow the chlorophyll-Cu derivatives to be fully adsorbed onto the surface of the biochar; and then filtered to separate the solid from the solution;

[0116] S12: The solid obtained by filtration is placed in a vacuum drying box at 0°C to dry to obtain a mixture containing chlorophyll-Cu derivatives (denoted as biochar loaded with chlorophyll-Cu derivatives).

[0117] 2. The specific method for degrading PFAS using the mixture containing chlorophyll-Cu derivatives is:

[0118] S21: The chlorophyll-Cu derivative loaded biochar prepared in S12 is added into a reaction container, and a H2O2 solution with a concentration of 303.55 g / L is slowly added dropwise, and the loaded biochar is magnetically stirred at a speed of 300 r / min for 20 min to make the loaded biochar and pure H2O2 fully contact and form a uniform system, to obtain a mixture containing chlorophyll-Cu derivative and H2O2, wherein the concentration of chlorophyll-Cu derivative in the mixture containing chlorophyll-Cu derivative and H2O2 is 0.1 g / L, and the concentration of H2O2 is 7.5 mg / L;

[0119] S22: The mixture containing chlorophyll-Cu derivative and H2O2 is mixed with soil containing PFAS, and then irradiated under a 550 nm light source for 20 min to degrade PFAS; wherein the mass ratio of soil containing PFAS (the concentration of PFAS is 309.5 ng / g, and the mass is 10 kg) to the mixture containing chlorophyll-Cu derivative and H2O2 is 3:1.

[0120] Example 11

[0121] 1. Preparation of a mixture containing chlorophyll-Cu derivative:

[0122] S11: Chlorophyll a is mixed with a first organic solvent methanol to obtain a first mixture; wherein the mass-volume ratio of chlorophyll a to methanol is 1 g:20 mL.

[0123] S12: The first mixture is mixed with an HCl solution for demetallization to obtain a second mixture; wherein the concentration of the HCl solution is 0.5 mol / L; and the volume ratio of the first mixture to the HCl solution is 1:2.

[0124] S13: The second mixture is mixed with a copper salt solution, and then subjected to microwave irradiation, the irradiation frequency is 2450 MHz, the irradiation temperature is 80°C, and the irradiation time is 10 min, to obtain a mixture containing chlorophyll-Cu derivative; wherein the copper salt solution is selected from a CuSO4 solution with a concentration of 0.25 mol / L, and the volume ratio of the second mixture to the copper salt solution is 1:1.

[0125] The pH of the mixture containing chlorophyll-Cu derivative is adjusted to 6.5.

[0126] 2. The specific method for degrading PFAS by using the mixture containing chlorophyll-Cu derivative is:

[0127] S21: mixing the mixture containing the chlorophyll-Cu derivative prepared in S13 and a H2O2 solution with a concentration of 303.55 g / L to obtain a mixture containing the chlorophyll-Cu derivative and H2O2, wherein the concentration of the chlorophyll-Cu derivative in the mixture containing the chlorophyll-Cu derivative and H2O2 is 0.2 g / L, and the concentration of H2O2 is 20 mg / L;

[0128] S22: mixing the mixture containing the chlorophyll-Cu derivative and H2O2 with the wastewater containing PFAS (the concentration of PFAS is 7.5 mg / L, and the volume is 10 L) to degrade the PFAS; wherein the mass ratio of the wastewater containing PFAS to the mixture containing the chlorophyll-Cu derivative and H2O2 is 3:1.

[0129] Examples 12 to 13

[0130] Except for adjusting the relevant parameters according to Table 1, the rest is the same as Example 11. Among them, in the mixture containing the chlorophyll-Cu derivative and H2O2, the concentration of the chlorophyll-Cu derivative is adjusted by adjusting the addition volume of the mixture containing the chlorophyll-Cu derivative; the concentration of H2O2 is adjusted by adjusting the addition volume of the H2O2 solution.

[0131] Example 14

[0132] Except for the "specific method for degrading PFAS by using the mixture containing the chlorophyll-Cu derivative" prepared according to the following method, the rest is the same as Example 11.

[0133] 2. The specific method for degrading PFAS by using the mixture containing the chlorophyll-Cu derivative is:

[0134] S21: mixing the mixture containing the chlorophyll-Cu derivative prepared in S13 and a H2O2 solution with a concentration of 303.55 g / L to obtain a mixture containing the chlorophyll-Cu derivative and H2O2, wherein the concentration of the chlorophyll-Cu derivative in the mixture containing the chlorophyll-Cu derivative and H2O2 is 0.2 g / L, and the concentration of H2O2 is 20 mg / L;

[0135] S22: mixing the mixture containing the chlorophyll-Cu derivative and H2O2 with the wastewater containing PFAS (the concentration of PFAS is 7.5 mg / L, and the volume is 10 L) to degrade the PFAS; wherein the mass ratio of the wastewater containing PFAS to the mixture containing the chlorophyll-Cu derivative and H2O2 is 3:1.

[0136] Table 1

[0137]

[0138] Note: " / " in Table 1 indicates that there is no corresponding preparation parameter, substance or performance parameter.

[0139] From the degradation rate results of Examples 1 to 14 in Table 1, it can be seen that the method of the present application has high PFAS degradation efficiency for degrading PFAS in soil or sewage.

[0140] In summary, the method of the present application for degrading PFAS can efficiently break the C-F bond in PFAS through the synergistic effect of chlorophyll-Cu derivative and H2O2, overcoming the difficulty of breaking the C-F bond in the prior art, and significantly improving the degradation efficiency of PFAS.

[0141] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for degrading PFAS, characterized in that, include: A mixture containing chlorophyll-Cu derivatives was mixed with an aqueous H2O2 solution to obtain a mixture containing chlorophyll-Cu derivatives and H2O2. The method for preparing the mixture containing chlorophyll-Cu derivatives includes: mixing chlorophyll a with a first organic solvent to obtain a first mixture, wherein the first organic solvent is selected from at least one of dichloromethane, methanol, ethanol, isopropanol, hexane, and acetone; mixing the first mixture with an acid solution to remove magnesium to obtain a second mixture; mixing the second mixture with a copper salt solution and then subjecting it to microwave irradiation to obtain the mixture containing chlorophyll-Cu derivatives; the microwave irradiation frequency is 1000MHz-2500MHz, the irradiation temperature is 50℃-90℃, and the irradiation time is 5min-60min; In the mixture containing chlorophyll-Cu derivative and H2O2, the concentration of chlorophyll-Cu derivative is 0.01 g / L-5 g / L, and the concentration of H2O2 is 5 mg / L-50 mg / L. The mixture containing chlorophyll-Cu derivative and H2O2 is mixed with a substance containing PFAS to degrade the PFAS; the mass ratio of the substance containing PFAS to the mixture containing chlorophyll-Cu derivative and H2O2 is (1-5):

1.

2. The method according to claim 1, characterized in that, The concentration of H2O2 in the aqueous solution is 273.2 g / L-303.55 g / L.

3. The method according to claim 1, characterized in that, In the mixture containing chlorophyll-Cu derivative and H2O2, the concentration of chlorophyll-Cu derivative is 0.1 g / L-0.3 g / L, and the concentration of H2O2 is 10 mg / L-30 mg / L; The pH value of the mixture containing chlorophyll-Cu derivatives is 2.0-7.

0.

4. The method according to claim 1, characterized in that, The method further includes the step of adding persulfate to the mixture containing chlorophyll-Cu derivative and H2O2; In the mixture containing chlorophyll-Cu derivatives and H2O2, the concentration of persulfate is 0.01 mol / L to 0.5 mol / L; the persulfate is selected from potassium persulfate or sodium persulfate.

5. The method according to claim 1, characterized in that, The mixture containing chlorophyll-Cu derivative and H2O2 is further processed with a light source after being mixed with a substance containing PFAS. The wavelength of the light source is 200nm-2000nm; the processing time of the light source at 50℃-80℃ is 10min-60min; In the mixture containing chlorophyll-Cu derivative and H2O2, the concentration of chlorophyll-Cu derivative is 0.05 g / L-5 g / L, and the concentration of H2O2 is 5 mg / L-50 mg / L.

6. The method according to claim 1, characterized in that, The mass-to-volume ratio of chlorophyll a to the first organic solvent is 1g:(10-50)mL; The volume ratio of the first mixture to the acid solution is 1:(1-3); the acid solution is selected from HCl solution with a concentration of 0.1mol / L-1mol / L, sulfuric acid solution with a concentration of 0.05mol / L-0.5mol / L, or acetic acid solution with a concentration of 0.5mol / L-2mol / L. The copper salt is selected from at least one of Cu(OAc)2, CuSO4, Cu(NO3)2 and CuCl2; the concentration of the copper salt solution is 0.01 mol / L-0.5 mol / L; The volume ratio of the second mixture to the copper salt solution is 1:(0.5-2).

7. The method according to claim 1, characterized in that, The microwave radiation process also includes the following steps: The mixture obtained after microwave irradiation was mixed with biochar to allow chlorophyll-Cu derivatives to be fully adsorbed onto the surface of the biochar. Then, solid-liquid separation was performed and the solid was dried. The mass ratio of the mixture obtained after microwave irradiation to the biochar is 1:(0.1-1). The drying temperature is -80℃ to 4℃.

8. The method according to any one of claims 1 to 5, characterized in that, The method for preparing the mixture containing chlorophyll-Cu derivatives includes: The biomass raw material is extracted with a second organic solvent, and the liquid is collected to obtain an extract containing chlorophyll a; wherein the biomass raw material includes at least one of spirulina, spinach and silkworm excrement; the second organic solvent is selected from at least one of dichloromethane, methanol, ethanol, isopropanol, hexane and acetone; The extract containing chlorophyll a is mixed with a third organic solvent, and the liquid is collected to obtain a third mixture, wherein the third organic solvent is selected from a methanol solution containing 1 w / v%-10 w / v% sodium hydroxide; The third mixture was mixed with a copper salt solution and then subjected to microwave irradiation at a frequency of 1000MHz-2500MHz, a temperature of 50℃-80℃, and a duration of 10min-60min. Solid impurities were then removed by filtration to obtain the mixture containing chlorophyll-Cu derivatives.

9. The method according to claim 8, characterized in that, The mass ratio of the biomass raw material to the second organic solvent is 1:(3-20); The volume ratio of the extract containing chlorophyll a to the third organic solvent is 1:(0.5-5). The copper salt is selected from at least one of Cu(OAc)2, CuSO4, Cu(NO3)2 and CuCl2; the concentration of the copper salt solution is 0.01 mol / L-0.5 mol / L; The mass ratio of the biomass raw material to the copper salt solution is 100:(1-10).

10. The application of the method according to any one of claims 1 to 9 in the purification treatment of household water containing PFAS, the purification treatment of wastewater containing PFAS, or the remediation of soil containing PFAS.

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