A method for the catalytic generation of non-radical treated soil leachate from a modified phthalocyanine photosensitizer

Abstract

The application relates to a method for treating soil leachate by using a modified phthalocyanine photosensitizer to generate non-radical treatment soil leachate. The method for treating soil leachate comprises the following steps: S1, providing a phthalocyanine photosensitizer with amphiphilic property; S2, mixing and contacting the phthalocyanine photosensitizer with soil leachate containing micellar-encapsulated organic pollutants to obtain a mixed solution; and S3, aerating the mixed solution obtained in the step S2, and realizing the degradation of the organic pollutants in the soil leachate under natural light irradiation. The application utilizes the characteristics that singlet oxygen is easy to enrich in the hydrophobic interior of the surfactant micelles and the characteristics that the singlet oxygen oxidation process is less affected by the water quality background components, efficiently removes the organic pollutants encapsulated by the surfactant micelles without destroying the surfactant molecules, and provides an effective method for soil leachate treatment and reuse.

Description

Technical Field

[0001] This invention relates to the field of soil remediation technology, and in particular to a method for treating soil leachate by catalyzing the generation of non-radicals using modified phthalocyanine photosensitizers. Specifically, it is a method for treating organic pollutants in soil leachate wastewater by catalyzing the generation of singlet oxygen using bond-modified phthalocyanine photosensitizers. Background Technology

[0002] Soil is not only the material basis for agricultural production but also a vital resource for the survival and development of humans and other organisms. With the expanding scope of human activities and the accelerating pace of urbanization and industrialization, soil organic pollution has become increasingly serious. Persistent organic pollutants (POPs) are a significant class of hydrophobic organic pollutants in soil, such as polycyclic aromatic hydrocarbons (e.g., naphthalene), organochlorine pesticides (e.g., heptachlor), and brominated flame retardants (e.g., polybrominated diphenyl ethers). Once these organic pollutants enter the soil, they are adsorbed by soil organic matter and minerals, leading to a significant reduction in their bioavailability and resulting in long retention times and difficulty in degradation. Soil organic pollutants are mostly characterized by strong bioaccumulation, persistence, and high toxicity, affecting crop growth and quality, seriously impacting ecological security and human health, and representing one of the most pressing soil pollution problems to be addressed.

[0003] Domestic and international scholars have conducted extensive research on organic soil remediation technologies. Among these, surfactant leaching remediation technology has attracted widespread attention due to its simplicity, high efficiency, short cycle time, and low cost and energy consumption, making it one of the most promising technologies for remediating organic soil. Surfactant leaching remediation technology primarily utilizes the solubilizing and flow-enhancing properties of surfactants to increase the solubility and fluidity of hydrophobic organic matter in the aqueous phase. This allows the surfactant to combine with the hydrophobic organic matter to form colloidal particles, which are then collected and processed in the aqueous phase to achieve the remediation goal. Surfactant leaching remediation technology can effectively separate hydrophobic organic pollutants such as polycyclic aromatic hydrocarbons, organochlorine pesticides, and brominated flame retardants from the soil, bringing the pollutants to the surface or easily collected and processed devices, thereby achieving the purpose of soil remediation. It is worth noting that although surfactant leaching technology extracts organic pollutants from the soil and achieves efficient remediation of organically contaminated soil, the organic pollutants are only migrated from the soil to the leaching solution and are not completely degraded or removed. Properly treating soil leaching wastewater not only reduces the environmental risks of organic pollutants but also enables the recycling and reuse of the leaching solution, significantly reducing the amount of surfactants used in the remediation process and economically and efficiently removing organic pollutants from the leaching wastewater. Therefore, how to treat the large amounts of surfactants and recalcitrant organic pollutants present in soil leaching wastewater is extremely important and a key issue in the promotion and application of soil leaching remediation technology, which has significant environmental and economic implications.

[0004] Traditional methods for treating surfactant leaching wastewater mainly include physical and biological methods. Physical methods involve physical or mechanical separation to treat the wastewater, such as air stripping, solvent extraction, adsorption, and membrane filtration, but these methods cannot achieve the degradation and detoxification of pollutants. Biological methods utilize the metabolism of microorganisms to transform organic pollutants into stable, harmless substances; however, the microbial cultivation cycle is long, and the treatment conditions are relatively stringent, making it impossible to achieve rapid and efficient treatment of surfactant leaching wastewater. In summary, the use of physical and biological methods to treat soil leaching wastewater has certain limitations.

[0005] In recent years, soil leachate treatment methods based on advanced oxidation technologies have attracted widespread attention. These methods typically utilize photocatalysis, electrocatalysis, ozone oxidation, Fenton reaction, and other mechanisms to generate hydroxyl radicals (·OH) and / or sulfate radicals (SO4··OH). - Free radical oxidation technology utilizes the strong oxidizing properties of free radicals to degrade and remove organic pollutants from soil leaching wastewater. However, background components in the leaching wastewater (such as surfactants, humic substances, and halide ions) can capture free radicals, easily interfering with the pollutant degradation process. Furthermore, organic pollutants in the leaching solution are mainly encapsulated in surfactant micelles, while free radicals have difficulty penetrating the micelles, increasing the difficulty of oxidative removal. Therefore, to ensure the desired pollutant removal effect, it is necessary to increase the free radical production. This increases treatment costs, and the surfactants in the leaching solution are oxidized along with the pollutants by free radicals, hindering the recycling of the leaching solution. In conclusion, considering the non-selective oxidation characteristics of free radicals and the water quality characteristics of soil leaching solution, the use of free radical oxidation technology to treat soil leaching wastewater also has certain limitations.

[0006] Phthalocyanine complexes possess a highly conjugated electronic system. Due to the strong electron interactions between the phthalocyanine rings, they exhibit excellent optical, electrical, thermal, magnetic properties and chemical stability, making them widely used in dyes, catalysts, and nonlinear optical materials. Metallic phthalocyanine complexes exhibit strong transitions in the visible light region, showing strong absorption in the visible light spectrum of natural light. Furthermore, they are non-toxic and harmless to the environment, making them a class of photosensitizers and photocatalysts with excellent performance. Summary of the Invention

[0007] To address the practical technical problems of difficult organic pollution treatment and low recovery efficiency in soil leachate, this invention provides a method for treating soil leachate by catalyzing the generation of non-radicals using modified phthalocyanine photosensitizers. This invention utilizes the characteristic that singlet oxygen readily accumulates within the hydrophobic interior of surfactant micelles and that the singlet oxygen oxidation process is less affected by background water composition. This method efficiently removes organic pollutants encapsulated in surfactant micelles without damaging surfactant molecules, providing an effective method for the treatment and reuse of soil leachate.

[0008] Surfactant micelles consist of a nonpolar core formed by the aggregation of the hydrophobic tails of surfactant molecules, while the hydrophilic heads face outwards and are in contact with the aqueous solution. Furthermore, most of the singlet oxygen within the micelles exists in a gaseous state, exhibiting a longer lifetime in a nonpolar environment compared to a polar one. The hydrophobic interior provides a relatively stable environment for the accumulation of singlet oxygen, causing molecules to spontaneously migrate to and adsorb within the micelles. Simultaneously, singlet oxygen reacts with organic contaminants within the surfactant molecules, further promoting their accumulation within the hydrophobic interior.

[0009] Phthalocyanine complexes are inherently insoluble in water. To enable them to bind to micelles in soil leachate and generate singlet oxygen in situ to oxidize organic pollutants within the micelles, amphiphilic groups are introduced. Utilizing the adsorption properties of both hydrophilic and hydrophobic groups, they bind to micelles at different sites, effectively degrading organic pollutants. Sulfonic acid groups, as hydrophilic groups, significantly improve the water solubility of phthalocyanine complexes. Furthermore, phthalocyanines containing an average of three sulfonic acid groups exhibit good dispersibility and higher singlet oxygen yields compared to disulfonic and tetrasulfonic phthalocyanines, demonstrating stable and efficient singlet oxygen generation.

[0010] This invention is achieved through the following scheme:

[0011] The purpose of this invention is to provide a method for treating soil leachate by catalyzing the generation of non-radical treatments using modified phthalocyanine photosensitizers, comprising the following steps:

[0012] S1. An amphiphilic phthalocyanine photosensitizer is provided, with the following structural formula:

[0013] Where M is iron, copper, cobalt, aluminum, nickel, magnesium, or zinc; R is a hydrophobic group, or a group obtained by freely combining a hydrophobic group and a hydrophilic group;

[0014] S2. The amphiphilic phthalocyanine photosensitizer is mixed and contacted with soil leachate containing organic pollutants encapsulated in micelles to obtain a mixture;

[0015] S3. Aerate the mixture from step S2 and degrade the organic pollutants in the soil leachate under natural light.

[0016] In some embodiments of the present invention, in step S1, the metal in the amphiphilic phthalocyanine photosensitizer is at least one of iron, copper, cobalt, aluminum, nickel, magnesium, and zinc.

[0017] In some embodiments of the present invention, in step S1, the hydrophilic group includes amino, carboxyl, hydroxyl, amide, sulfonic acid, and their derivatives; the hydrophobic group includes halogen, hydrocarbon, phenyl, and their derivatives. The term "derivative" refers to a more complex product derived from a simple compound by replacing an atom or group of atoms with other atoms or groups; for example, acyl halides, acid anhydrides, and esters are derivatives of carboxylic acids.

[0018] Furthermore, the amphiphilic modified phthalocyanine complex has at least four substituents, of which at least three are sulfonic acid groups and directly substituted on the phthalocyanine ring.

[0019] The substituents other than the sulfonic acid group are selected from at least one or a combination of halogen, hydrocarbon, amino, carboxyl, hydroxy, amide, and hydroxyphenyl substituents.

[0020] Preferably, the modified phthalocyanine complex has at least one substituent other than the sulfonic acid group. In one embodiment, the substituent is a carboxyl group. Phthalocyanine complexes containing carboxyl functional groups can form hydrogen bonds with corresponding groups (such as amino, hydroxyl, etc.) in surfactant molecules, enhancing their binding to micelles and improving their ability to adsorb onto micelles and thus increasing their ability to oxidatively degrade organic pollutants. In another embodiment, the modified phthalocyanine complex derivative includes at least one or a combination of the following substituents: halogen, hydrocarbon, amino, carboxyl, hydroxyl, amide, sulfonic acid, and hydroxyphenyl, wherein halogens include, but are not limited to, chlorine, bromine, and iodine, and carboxylic acid derivatives include, but are not limited to, acyl halides, acid anhydrides, and esters. Examples of the modified phthalocyanine complexes of the present invention include, but are not limited to, 2-ethyl acetate trisulfonate phthalocyanine, 2-ethyl acetoacetate trisulfonate phthalocyanine, and 2-(4-hydroxyphenyl)trisulfonate phthalocyanine.

[0021] In some embodiments of the present invention, the mass ratio of the amphiphilic phthalocyanine photosensitizer to the soil leachate containing micelle-encapsulated organic pollutants is 1:1 to 1:200.

[0022] In some embodiments of the present invention, the amphiphilic phthalocyanine photosensitizer is prepared by the following method:

[0023] a. Provide metal chlorides, phthalonitriles, chlorosulfonic acid, thionyl chloride, and R-group precursors;

[0024] b. Mix and heat the phthalonitrile and metal chloride, cool, grind and wash, and vacuum dry to obtain a monosubstituted phthalocyanine solid.

[0025] c. Add the R-group precursor to the phthalocyanine solid obtained in step b, pressurize and heat for the first time. After the liquid has completely disappeared, add chlorosulfonic acid and heat for the second time. Then add thionyl chloride and heat for the third time. After heating, cool and let stand. Place in an ice bath at 0°C for 15-60 min (preferably 30-45 min) for hydrolysis and filter to obtain crude phthalocyanine complex with amphiphilic group modification. Dissolve it in distilled water. To achieve product purification, control the pH to 8-10, for example, pH 8, 9, 10. Filter and evaporate the filtrate to obtain pure phthalocyanine complex with amphiphilic group modification.

[0026] In some embodiments of the present invention, in step b, the mass ratio of the metal chloride to the phthalonitrile is 1:1-1:30, preferably 1:2-1:15, and even more preferably 1:2-1:8;

[0027] The metal chloride is at least one of iron, copper, cobalt, aluminum, nickel, magnesium, and zinc.

[0028] In some embodiments of the present invention, in step b, the heating temperature is 180℃-240℃, preferably 190℃-220℃; the heating time is 4-12h, preferably 5-8h. Heating is stopped when the solid phase transforms into a liquid phase and becomes dark green due to the formation of phthalocyanine rings. After cooling to room temperature, the phthalocyanine solid is removed and ground into a fine powder. It is then repeatedly washed with distilled water and concentrated sulfuric acid, filtered at least three times, and dried to obtain pure phthalocyanine solid.

[0029] In some embodiments of the present invention, in step c, the mass ratio of sulfonium chloride to chlorosulfonic acid is 1:1-1:20, preferably 1:1-1:15, and even more preferably 1:3-1:10; in a specific embodiment, a 0.1M-1.0M, preferably 0.2M-0.8M, sulfonium chloride solution and a 0.1M-0.6M, preferably 0.1M-0.3M chlorosulfonic acid solution are prepared.

[0030] The mass ratio of phthalocyanine solid to hydrophilic precursor is 1:1-1:80, preferably 1:2-1:50, and even more preferably 1:2-1:30; the mass ratio of phthalocyanine solid to hydrophobic precursor is 1:1-1:120, preferably 1:2-1:90, and even more preferably 1:4-1:70.

[0031] The initial heating temperature is 50-110℃, preferably 60-90℃; the pressure is 3-20MPa, preferably 7-15MPa; and the stirring time is 3-12h, preferably 4-8h.

[0032] The second heating temperature is 60-150℃, preferably 80-100℃, and the heating time is 1-4h, preferably 2-3h; then the heating is stopped and stirring is continued, and after cooling to 40-50℃, the 0.2M-0.8M thionyl chloride solution from step b is added in 2-8 equal portions, preferably 3-5 portions.

[0033] The temperature for the third heating is 90-100℃, and the heating time is 2-6 hours, preferably 3-4 hours;

[0034] It also includes the purification of phthalocyanine complexes with amphiphilic groups. The amphiphilic phthalocyanine complexes are dissolved in distilled water, the pH of the mixture is adjusted to 8-10, the mixture is filtered, and the filtrate is heated and evaporated to obtain the purified amphiphilic phthalocyanine complexes.

[0035] In some embodiments of the present invention, the organic pollutants include naphthalene and pentachlorophenol.

[0036] Other steps or operations may be included before, after, or between steps (1)-(3) or (a)-(d) of the present invention, for example, to further optimize and / or improve the method described in the present invention. In some embodiments, the method further includes the step of washing the filter with distilled water and drying it.

[0037] The technical solution of the present invention has the following advantages over the prior art:

[0038] The present invention provides a method for preparing phthalocyanine complexes with amphoteric group modification, applicable to different metal elements, with low energy consumption, diverse structures, wide range of uses, and readily available raw materials.

[0039] This invention utilizes substituents such as sulfonic acid groups, amide groups, and carboxyl groups to form stable chemical bonds with phthalocyanine rings. Furthermore, the hydrophilic properties of the substituents greatly improve its water solubility, enabling it to effectively bind micelles in soil leachate.

[0040] The modified phthalocyanine complex of this invention enhances its photocatalytic activity, effectively increases the singlet oxygen yield, and achieves efficient treatment of organic polluted soil leaching wastewater. At the same time, it ensures that the surfactants in the soil leaching solution are not destroyed, which is conducive to the recycling and reuse of surfactants.

[0041] The modified phthalocyanine complexes of this invention exhibit long-lasting catalytic activity and are easy to separate, which is beneficial for surfactant recovery. Detailed Implementation

[0042] The present invention will be further described below with reference to specific embodiments, so that those skilled in the art can better understand and implement the present invention, but the embodiments are not intended to limit the present invention.

[0043] 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 the upper and lower limits of the range and each intermediate value between them are 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, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0044] 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 to which this invention is described. While only preferred methods and materials are 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. Unless otherwise stated, “%” means percentage based on weight.

[0045] Example 1

[0046] This embodiment provides a method for generating non-radical treatment of soil leachate using a modified phthalocyanine photosensitizer, specifically including the following steps:

[0047] (I) Synthesis of modified phthalocyanine photosensitizers: (1) Weigh 2g of ferrous chloride, weigh phthalonitrile at a mass ratio of 1:4 for ferrous chloride and mix it evenly with ferrous chloride. Add it to a solid-phase reactor with a controlled temperature of 200℃ and continue stirring and heating for 8h. Stop heating when the solid phase is completely converted into liquid phase and is dark green. After cooling to room temperature, take out the crude phthalocyanine iron solid, place it in a mortar and grind it into fine solid powder. Wash it with distilled water and concentrated sulfuric acid in sequence and filter it. Repeat the operation three times and then dry it to obtain pure unsubstituted phthalocyanine iron solid.

[0048] (2) The dried unsubstituted iron phthalocyanine solid was mixed with 0.1M ethyl 2-chloroacetoacetate in pure ethanol at a mass ratio of 1:1. The mixture was stirred and heated at 60℃ and 8MPa for 6 hours. After filtration and drying, monosubstituted ethyl acetoacetate iron phthalocyanine (β-substituted) was obtained. After cooling, 0.3M chlorosulfonic acid solution was added. The mixture was heated and stirred at 80℃ for 3 hours. Heating was stopped but stirring was continued. When the solution cooled to 40℃, 0.2M thionyl chloride solution was added in three equal portions according to a mass ratio of 1:8 of thionyl chloride to chlorosulfonic acid. The mixture was then heated to 90℃ and the reaction was stopped after 4 hours. The mixture was then allowed to stand for 15 minutes. The solution was poured into ice water at 0°C and hydrolyzed for 45 minutes. After filtration, crude monosubstituted ethyl acetoacetate trisulfonic phthalocyanine iron (β-substituted) was obtained. Then, it was dissolved in distilled water to wash away the solvent and impurities adhering to the crystal surface. The pH was controlled at 9. Insoluble impurities (such as unreacted raw materials) were removed by filtration and the filtrate was evaporated to obtain pure monosubstituted ethyl acetoacetate trisulfonic phthalocyanine iron (β-substituted).

[0049]

[0050] (II) Steps for treating soil leachate: Using the monosubstituted ethyl acetoacetate trisulfonate phthalocyanine iron (β-substituted) obtained in step (I) at a mass ratio of 1:30, the monosubstituted ethyl acetoacetate trisulfonate phthalocyanine iron (β-substituted) is added to the soil leachate to be treated. The pH is controlled at 5 during the catalytic oxidation reaction. Oxygen is introduced into the mixture and aerated for 2 hours. Under sufficient oxygen and continuous stirring, singlet oxygen is generated by irradiation with natural light. The singlet oxygen reacts fully with the organic pollutants for 4 hours to achieve the oxidation treatment of the soil leachate wastewater.

[0051] (III) Results Testing: 1 mL samples of the treated soil leaching wastewater and the untreated leaching wastewater were taken and tested by high performance liquid chromatography. The appropriate detection wavelength for organic pollutants (such as naphthalene and pentachlorophenol) was determined by ultraviolet / visible spectrophotometer. The concentration of pollutants before and after treatment was obtained by using the linear relationship between the main peak area and concentration of pollutants at different concentrations. The pollutant removal rate was then calculated. The results are shown in Table 1.

[0052] Example 2

[0053] This embodiment is another exemplary method for treating soil leaching wastewater. Unlike embodiment 1, in this embodiment, the pressure is 10 MPa when the solid phthalocyanine iron is mixed with ethyl 2-chloroacetoacetate.

[0054] Example 3

[0055] This embodiment is another exemplary method for treating soil leaching wastewater. Unlike embodiment 1, in this embodiment, the pressure is 12 MPa when the solid phthalocyanine iron is mixed with ethyl 2-chloroacetoacetate.

[0056] Example 4

[0057] This embodiment is another exemplary method for treating soil leaching wastewater. The difference from Embodiment 1 is that in this embodiment, the mass ratio of monosubstituted ethyl acetoacetate trisulfonic acid phthalocyanine iron (β-substituted) to soil leaching liquid is 1:10.

[0058] Example 5

[0059] This embodiment is another exemplary method for treating soil leaching wastewater. The difference from Embodiment 1 is that in this embodiment, the mass ratio of monosubstituted ethyl acetoacetate trisulfonic acid phthalocyanine iron (β-substituted) to soil leaching liquid is 1:50.

[0060] Example 6

[0061] This embodiment is another exemplary method for treating soil leaching wastewater. The difference from Embodiment 1 is that in this embodiment, the mass ratio of monosubstituted ethyl acetoacetate trisulfonic acid phthalocyanine iron (β-substituted) to soil leaching liquid is 1:60.

[0062] Example 7

[0063] This embodiment is another exemplary method for treating soil leaching wastewater. Unlike embodiment 1, in this embodiment, the temperature is 70°C when the solid phthalocyanine iron is mixed with ethyl 2-chloroacetoacetate.

[0064] Example 8

[0065] This embodiment is another exemplary method for treating soil leaching wastewater. Unlike embodiment 1, in this embodiment, the temperature is 90°C when the solid phthalocyanine iron is mixed with ethyl 2-chloroacetoacetate.

[0066] Example 9

[0067] This embodiment is another exemplary method for treating soil leaching wastewater. Unlike embodiment 1, in this embodiment, when the crude monosubstituted ethyl acetoacetate trisulfonic acid phthalocyanine iron (β-substituted) is dissolved in distilled water for purification, the pH is controlled at 8.

[0068] Example 10

[0069] This embodiment is another exemplary method for treating soil leaching wastewater. Unlike embodiment 1, in this embodiment, when the crude monosubstituted ethyl acetoacetate trisulfonic acid phthalocyanine iron (β-substituted) is dissolved in distilled water for purification, the pH is controlled at 10.

[0070] Comparative Example 1

[0071] This comparative example is another exemplary method for treating soil leaching wastewater. Unlike Example 1, this comparative example does not include ethyl 2-chloroacetoacetate, chlorosulfonic acid, and thionyl chloride for substitution reactions.

[0072] Test case

[0073] Table 1 shows the organic pollutant removal rates determined by the treatment methods in Examples 1-3.

[0074] Table 1

[0075]

[0076]

[0077] The results of Examples 1 and 2-3 in Table 1 above show that the pressure during the reaction of solid phthalocyanine iron with ethyl 2-chloroacetoacetate affects the treatment effect of the method described in this invention. The method of this invention works best under high pressure conditions, preferably 7-15 MPa, with 10 MPa being the optimal pressure for treating organic pollutants in the examples. Lower pressure slows down the primary substitution process, resulting in poorer conversion and a lower yield in the subsequent trisubstituted sulfonic acid group process, thus slightly reducing catalytic efficiency. Higher pressure, on the other hand, reduces the efficiency of the primary substitution process, making disubstituted or even multisubstituted processes more likely, leading to changes in the properties of the photosensitizer catalyst itself and a decrease in catalytic efficiency.

[0078] As shown in Table 1 above, the mass ratio of the amphiphilic modified phthalocyanine complex to the soil leachate affects the treatment effect. When the mass ratio of monosubstituted ethyl acetoacetate trisulfonic acid phthalocyanine iron (β-substituted) to the soil leachate is 1:50, the treatment effect on organic pollutants in the leachate is better. If the mass ratio of the amphiphilic modified phthalocyanine complex to the soil leachate is too low, the catalyst content is relatively low, the photocatalytic oxidation effect is poor, and the singlet oxygen yield is low, which is insufficient to effectively degrade organic pollutants. If the mass ratio is too high, the concentration of the phthalocyanine complex is too high, making it difficult for natural light to penetrate into the micelles, thus affecting singlet oxygen generation.

[0079] As can be seen from the results of Examples 1 and 7-8 in Table 1 above, the temperature during the reaction of phthalocyanine iron solid with ethyl 2-chloroacetoacetate affects the treatment effect of the method described in this invention. The method achieves better treatment effect at 70°C. When the temperature is too low, phthalocyanine iron solid and ethyl 2-chloroacetoacetate are difficult to undergo substitution reaction on the phthalocyanine ring, the number of amphiphilic groups is small and it is difficult to form hydrogen bonds with the corresponding groups in the surfactant molecule, resulting in poor binding ability with micelles and a decrease in catalytic oxidation effect; when the temperature is too high, the substituent precursor is easily pyrolyzed, producing other side reactions, reducing the yield of the subsequent target catalyst, and affecting the generation of singlet oxygen.

[0080] As can be seen from the results of Examples 1 and 9-10 in Table 1 above, the pH concentration during the purification of monosubstituted ethyl acetoacetate trisulfonate phthalocyanine iron (β-substituted) affects the treatment effect of the method described in this invention. The method for purifying monosubstituted ethyl acetoacetate trisulfonate phthalocyanine iron (β-substituted) achieves better results under alkaline conditions with a pH of 9. Too low a pH easily disrupts the stable system of the phthalocyanine complex, reducing the catalytic effect; too high a pH easily leads to hydrolysis, which is detrimental to micelle binding.

[0081] As can be seen from the results of Example 1 and Comparative Example 1 in Table 1 above, the absence of ethyl 2-chloroacetoacetate, chlorosulfonic acid, and sulfoxide in the reaction affects the treatment effect of the method described in this invention. Ethyl 2-chloroacetoacetate, chlorosulfonic acid, and sulfoxide participate in the reaction as precursors of hydrophilic and hydrophobic groups, respectively. Ferrophthalocyanine without amphiphilic modification is difficult to dissolve in soil leachate, lacks adsorption properties and binds to micelles, resulting in low singlet oxygen yield and difficulty in penetrating the micelles to oxidize and degrade organic pollutants.

[0082] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for treating soil leachate by catalyzing the generation of free radicals using a modified phthalocyanine photosensitizer, characterized in that, Includes the following steps: S1. An amphiphilic phthalocyanine photosensitizer is provided, with the following structural formula: Where M is iron, copper, cobalt, aluminum, nickel, magnesium, or zinc; R is a hydrophobic group, or a group obtained by freely combining a hydrophobic group and a hydrophilic group; S2. The amphiphilic phthalocyanine photosensitizer is mixed and contacted with soil leachate containing organic pollutants encapsulated in micelles to obtain a mixture; S3. Aerate the mixture in step S2 and degrade the organic pollutants in the soil leachate under natural light. The amphiphilic phthalocyanine photosensitizer was prepared by the following method: a. Provide metal chlorides, phthalonitriles, chlorosulfonic acid, thionyl chloride, and R-group precursors; b. Mix and heat the phthalonitrile and metal chloride, cool, grind and wash, and vacuum dry to obtain phthalocyanine solid. c. Add the R-group precursor to the phthalocyanine solid obtained in step b, pressurize and heat for the first time. After the liquid has completely disappeared, add chlorosulfonic acid and heat for the second time. Then add thionyl chloride and heat for the third time. After heating, cool, place in an ice bath for hydrolysis and filter. Evaporate the filtrate to obtain the phthalocyanine complex with amphiphilic group modification.

2. The method according to claim 1, characterized in that, In step S1, the hydrophobic group includes halogens, hydrocarbon groups, phenyl groups and their derivatives.

3. The method according to claim 1, characterized in that, In step S1, the hydrophilic groups include amino, carboxyl, hydroxyl, amide, sulfonic acid and their derivatives.

4. The method according to claim 1, characterized in that, In step b, the mass ratio of the metal chloride to the phthalonitrile is 1:1 to 1:30; The metal chloride is at least one of iron, copper, cobalt, aluminum, nickel, magnesium, and zinc.

5. The method according to claim 1, characterized in that, In step b, the heating temperature is 180℃-240℃, and the heating time is 4-12h.

6. The method according to claim 1, characterized in that, In step c, the mass ratio of thionyl chloride to chlorosulfonic acid is 1:1 to 1:20, and the mass ratio of phthalocyanine solid to chlorosulfonic acid is 1:1 to 1:

100. The mass ratio of phthalocyanine solid to R-group precursor is 1:1 to 1:

80.

7. The method according to claim 1, characterized in that, In step c, the temperature for the first heating is 50-110℃, and the pressure is 3-20MPa; The second heating temperature is 60-150℃, and the heating time is 1-4 hours; The third heating stage involves raising the temperature to 90-100℃ and heating for 2-6 hours. It also includes the purification of phthalocyanine complexes with amphiphilic groups. The amphiphilic phthalocyanine complexes are dissolved in distilled water, the pH of the mixture is adjusted to 8-10, the mixture is filtered, and the filtrate is heated and evaporated to obtain the purified amphiphilic phthalocyanine complexes.

8. The method according to claim 1, characterized in that, In step S2, the mass ratio of the amphiphilic phthalocyanine photosensitizer to the soil leachate containing micellar-encapsulated organic pollutants is 1:1 to 1:

200.

9. The method according to claim 1, characterized in that, The organic pollutants include naphthalene and pentachlorophenol.

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