A solubilizing agent and its application in oxidation remediation of petroleum hydrocarbon contaminated soil

Abstract

The present invention relates to a solubilizing agent and its use in the oxidative remediation of petroleum hydrocarbon-contaminated soil. The solubilizing agent comprises alkaline protease, potassium fatty acid soap, and sodium lauryl sulfate. The solubilizing agent can be used in combination with persulfate to oxidatively remediate petroleum hydrocarbon-contaminated soil. This application method effectively couples the enhanced solubilization and oxidative degradation processes, improving the oxidative remediation efficiency of petroleum hydrocarbon-contaminated soil, achieving a high petroleum hydrocarbon removal rate, and being environmentally friendly, thus possessing promising application prospects.

Description

Technical Field

[0001] The present invention relates to the field of soil remediation, and in particular to a solubilizer and its application in the oxidation remediation of petroleum hydrocarbon-contaminated soil. Background Art

[0002] Petroleum hydrocarbons are primarily a mixture of hydrocarbons composed of carbon and hydrogen, primarily including straight-chain alkanes, cycloalkanes, olefins, and polycyclic aromatic hydrocarbons. Petroleum emissions from production processes such as extraction, storage, processing, refining, and transportation cause significant environmental pollution, particularly to the soil. According to the 2014 China Soil Pollution Survey, 23.6% of the 494 soil sites surveyed in 13 oil production areas exceeded standards, with petroleum hydrocarbons being the primary pollutant. Petroleum hydrocarbons entering the soil can also cause a series of significant ecological impacts on soil plants, animals, and microorganisms. Therefore, remediation of petroleum hydrocarbon-contaminated soils is necessary.

[0003] Chemical oxidation remediation technology is widely favored due to its advantages such as short remediation cycle, high remediation efficiency, and no influence from pollutant concentration. Chemical oxidants commonly used in in-situ chemical oxidation remediation include hydrogen peroxide (H2O2), permanganate (MnO4 - ), ozone (O3) and persulfate (S2O8 2- ). Among them, persulfate is a new type of oxidant that has been widely researched and applied in recent years. It features good stability, high solubility in water, a wide pH range, and diverse activation methods. However, petroleum hydrocarbons are highly hydrophobic substances that bind tightly to soil organic matter and other components. Therefore, the remediation efficiency of persulfate alone is not ideal. This is mainly manifested in the fact that even with the addition of a large amount of oxidant, the removal efficiency of petroleum hydrocarbons is not high.

[0004] To improve the remediation efficiency of petroleum hydrocarbon-contaminated soil, methods can be used to desorb petroleum hydrocarbons from the soil and release them into the aqueous phase to promote the reaction between oxidants and petroleum hydrocarbons. Surfactants are a commonly used chemical reagent that can desorb pollutants from soil by increasing the solubility of pollutants. Due to the wide differences in the structures and properties of different surfactants, the structural properties of pollutants vary greatly, and the composition and properties of the soil have a significant impact on the surfactant's solubilization of pollutants. Randomly adding surfactants does not achieve a good solubilization effect on specific pollutants. It is necessary to screen the appropriate surfactant type and parameters based on the properties of the pollutants. The document "Chemosphere 2004, 57:1139-1150" found that the elution effect of different surfactants on petroleum hydrocarbons varies greatly. Therefore, it is necessary to comprehensively consider the properties of the pollutants, the properties of the soil, and the properties of the surfactants and synergists to develop effective and enhanced solubilization formulas. Since the goal of soil contamination remediation is to remove pollutants and reduce the ecological and health risks of the soil, the various additives used in remediation should be as environmentally friendly as possible. However, current research focuses more on the solubilization and elution effects, and pays less attention to the environmental friendliness of the additives.

[0005] Solubilization and elution can transfer pollutants from the soil phase to the aqueous solution phase to a certain extent, but the pollutants are not completely removed, and the fundamental purpose of soil remediation is not achieved. The eluent containing pollutants requires further treatment, which also requires appropriate technology and corresponding costs. If surfactants are used to enhance solubilization, and then oxidants such as persulfates are added to the same remediation system for oxidative remediation, the treatment process can be simplified to a certain extent compared to first eluting out the pollutants and then treating the eluent, and the treatment cost can be reduced. However, enhanced solubilization and oxidative degradation are two significantly different chemical processes. How to achieve effective coupling of these two processes to achieve the best remediation effect for specific pollutants (such as petroleum hydrocarbons) in complex soil systems is very worthy of relevant research. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention provides a solubilizing agent and its application in the oxidative remediation of petroleum hydrocarbon-contaminated soil. This solubilizing agent can be used in combination with persulfate to oxidatively remediate petroleum hydrocarbon-contaminated soil. This application method effectively couples the enhanced solubilization and oxidative degradation processes, improving the oxidative remediation efficiency of petroleum hydrocarbon-contaminated soil, achieving a high petroleum hydrocarbon removal rate and being environmentally friendly, thus possessing promising application prospects.

[0007] The invention provides a solubilizing agent comprising alkaline protease, fatty acid potassium soap and sodium lauryl sulfate.

[0008] According to the present invention, in the solubilizer, the mass ratio of alkaline protease, fatty acid potassium soap, and sodium lauryl sulfate is (0.5-2):1:(0.5-3), preferably (0.8-1.2):1:(1-2).

[0009] According to the present invention, the pH of the solubilizer is 5 to 13, preferably 9 to 10. The specific pH value can be, but is not limited to, the following: 6, 7, 8, 9, 10, 11, 12.

[0010] According to the present invention, the enzymatic activity of the alkaline protease is 500-6000 U / mL, preferably 3000-5000 U / mL.

[0011] According to the present invention, the carbon number of the fatty acid potassium soap is C12~C20, preferably C14~C18.

[0012] According to the present invention, the solubilizing agent can be prepared according to a conventional method for preparing a composite system solution. Preferably, a pH adjuster can be added to adjust the pH of the solution during preparation. The pH adjuster can be at least one of potassium hydroxide, sodium hydroxide, and calcium hydroxide, preferably potassium hydroxide.

[0013] The present invention also provides the use of the solubilizing agent in the oxidation remediation of petroleum hydrocarbon-contaminated soil, wherein the method of the application comprises the following steps:

[0014] The solubilizing agent is added to the petroleum hydrocarbon contaminated soil for solubilization treatment; then persulfate is added for oxidation treatment to obtain the repaired soil.

[0015] According to the present invention, the solubilizer comprises: alkaline protease, fatty acid potassium soap, and sodium lauryl sulfate.

[0016] According to the present invention, preferably, the mass ratio of alkaline protease, fatty acid potassium soap, and sodium lauryl sulfate is (0.5-2):1:(0.5-3), preferably (0.8-1.2):1:(1-2).

[0017] According to the present invention, preferably, a pH adjuster may be added to adjust the pH of the solubilizer to 5-13, preferably 9-10.

[0018] According to the present invention, preferably, the pH adjuster can be at least one of potassium hydroxide, sodium hydroxide, and calcium hydroxide, preferably potassium hydroxide.

[0019] According to the present invention, preferably, the fatty acid potassium soap may have carbon atoms ranging from C12 to C20, preferably C14 to C18.

[0020] According to the present invention, preferably, the enzymatic activity of the alkaline protease is 500-6000 U / mL, preferably 3000-5000 U / mL.

[0021] According to the present invention, further, the specific form of the solubilizer is a solution; the concentration of the solubilizer solution is 2000~40000 mg / L, preferably 15000~25000 mg / L.

[0022] According to the present invention, further, the mass ratio of the petroleum hydrocarbon contaminated soil to the solubilizer solution is 1:2 to 1:10, preferably 1:4 to 1:6.

[0023] According to the present invention, further, the solubilization treatment time is 2 to 40 h, preferably 20 to 30 h.

[0024] According to the present invention, further, the persulfate may be any soluble persulfate, preferably at least one of sodium persulfate, potassium persulfate and ammonium persulfate.

[0025] According to the present invention, further, the amount of persulfate added per gram of contaminated soil is 0.20-1.00 g, preferably 0.40-0.60 g.

[0026] According to the present invention, further, the oxidation treatment time is 1 to 240 h, preferably 120 to 180 h.

[0027] According to the present invention, further, the petroleum hydrocarbon is a hydrophobic organic pollutant, which can be straight-chain alkanes, cycloalkanes, olefins and polycyclic aromatic hydrocarbons, preferably straight-chain alkanes; the concentration of petroleum hydrocarbons in the contaminated soil is 800~4000 mg / kg, preferably 1800~2400 mg / kg.

[0028] According to the present invention, preferably, after adding the persulfate, the mixture is ultrasonicated and / or heated; the ultrasonication time is 1 to 6 hours, preferably 2 to 4 hours; the heating temperature is 30 to 80°C, preferably 50 to 60°C.

[0029] Compared with the prior art, the advantages of the present invention are:

[0030] This invention has developed a solubilizing agent formed by compounding a novel, environmentally friendly additive, alkaline protease, with the anionic surfactants, potassium fatty acid soap, and sodium lauryl sulfate. By combining these three components in a specific ratio, the solubilization effect on petroleum hydrocarbons can be further enhanced. Adjusting the pH with potassium hydroxide further strengthens the solubilization. This alkaline condition simultaneously activates persulfate. Furthermore, this system can be combined with ultrasonic and thermal activation to improve the oxidative remediation efficiency of petroleum hydrocarbon-contaminated soil.

[0031] The alkaline protease used in the present invention is a biological agent extracted from microorganisms and composed of multiple polypeptide chains. It has the advantages of being non-toxic and harmless. In addition, the adjuvant has good mutual solubility with anionic surfactants. Through reasonable proportioning and pH adjustment, it can significantly enhance the surfactant's solubilization effect on petroleum hydrocarbon pollutants and further improve the oxidative removal efficiency of pollutants by oxidants such as persulfate. The application method of the present invention not only comprehensively considers the coupling of solubilization and oxidation of pollutants, significantly improving the solubilization and oxidation efficiency, but also takes into account the environmental friendliness of the adjuvant, and has excellent application prospects. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with specific embodiments, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0033] In the present invention, in the examples and comparative examples, the mass of petroleum hydrocarbons in the solution and in the soil was determined using an infrared oil meter according to the method "Determination of Petroleum in Soil by Infrared Spectrophotometry" (HJ1051-2019);

[0034] The calculation formula of solubilization rate is:

[0035] Solubilization rate (%) = mass M of petroleum hydrocarbon dissolved in the solution w / Mass of petroleum hydrocarbons in the original contaminated soil M S0 ×100%;

[0036] The formula for calculating the oxidation rate is:

[0037] Oxidation rate (%) = (mass of petroleum hydrocarbons in the original contaminated soil M S0 -The mass of petroleum hydrocarbons dissolved in the solution M w -The mass of petroleum hydrocarbons remaining in the soil after oxidation M SR ) / mass of petroleum hydrocarbons in the original contaminated soil M S0 ×100%.

[0038] Example 1:

[0039] Prepare a solubilizer solution: Prepare a solution of alkaline protease, fatty acid potassium soap, and sodium lauryl sulfate in a mass ratio of 1:1:2, with water as the solvent. Adjust the pH of the solubilizer solution to 10 with potassium hydroxide. The concentration of the solubilizer solution is 25,000 mg / L. The alkaline protease activity is 5,000 U / mL, and the fatty acid potassium soap has 16 carbon atoms.

[0040] The concentration of petroleum hydrocarbons in the contaminated soil was 1800 mg / kg, consisting of straight-chain alkanes. The petroleum hydrocarbon-contaminated soil and solubilizer solution were mixed at a mass ratio of 1:5. The mixture was then placed on a disc shaker and allowed to react at 60 rpm / min at room temperature (20°C) for 24 hours to obtain a mixture. One-fifth of the mixture was centrifuged in a high-speed centrifuge. After solid-liquid separation, the mass of petroleum hydrocarbons in the supernatant was measured, and the solubilization rate of petroleum hydrocarbons was calculated (see Table 1).

[0041] Sodium persulfate was added to the remaining unseparated mixture according to the stoichiometric ratio to conduct an oxidation experiment. The amount of persulfate added was 0.5 g per gram of contaminated soil. The sample was then placed on a thermostatic shaker at 60°C for 120 hours. After centrifugation in a high-speed centrifuge and solid-liquid separation, the mass of petroleum hydrocarbons remaining in the oxidized soil was measured, and the petroleum hydrocarbon oxidation rate was calculated (see Table 1).

[0042] Example 2

[0043] Prepare a solubilizer solution: Prepare a solution containing alkaline protease, potassium fatty acid soap, and sodium lauryl sulfate in a mass ratio of 1:1:2, with water as the solvent. The concentration of the solubilizer solution is 25,000 mg / L. Without adding a pH adjuster, the pH of the solubilizer solution is 8.4. The alkaline protease activity is 5,000 U / mL, and the potassium fatty acid soap has 16 carbon atoms.

[0044] The concentration of petroleum hydrocarbons in the contaminated soil was 1800 mg / kg, consisting of linear alkanes. The petroleum hydrocarbon-contaminated soil and the solubilizer solution were mixed at a mass ratio of 1:5. The mixture was then placed on a disk shaker and allowed to react at 60 rpm / min at room temperature (20°C) for 24 hours to obtain a mixture. The solubilization efficiency was determined according to the method in Example 1, as shown in Table 1.

[0045] Oxidation experiments were conducted by adding sodium persulfate according to the stoichiometric ratio. The persulfate dosage was 0.5 g per gram of contaminated soil. The samples were then placed on a thermostatic shaker at 60°C for 120 hours. After centrifugation in a high-speed centrifuge and solid-liquid separation, the mass of petroleum hydrocarbons remaining in the oxidized soil was measured, and the petroleum hydrocarbon oxidation rate was calculated (see Table 1).

[0046] Example 3

[0047] Prepare a solubilizer solution: Prepare a solution containing alkaline protease, fatty acid potassium soap, and sodium lauryl sulfate in a mass ratio of 0.5:1:3, with water as the solvent. Adjust the pH of the solubilizer solution to 10 with potassium hydroxide. The concentration of the solubilizer solution is 25,000 mg / L. The alkaline protease activity is 5,000 U / mL, and the fatty acid potassium soap has 16 carbon atoms.

[0048] The concentration of petroleum hydrocarbons in the contaminated soil was 1800 mg / kg, consisting of linear alkanes. The petroleum hydrocarbon-contaminated soil and the solubilizer solution were mixed at a mass ratio of 1:5. The mixture was then placed on a disk shaker and allowed to react at 60 rpm / min at room temperature (20°C) for 24 hours to obtain a mixture. The solubilization efficiency was determined according to the method in Example 1, as shown in Table 1.

[0049] Oxidation experiments were conducted by adding sodium persulfate according to the stoichiometric ratio. The persulfate dosage was 0.5 g per gram of contaminated soil. The samples were then placed on a thermostatic shaker at 60°C for 120 hours. After centrifugation in a high-speed centrifuge and solid-liquid separation, the mass of petroleum hydrocarbons remaining in the oxidized soil was measured, and the petroleum hydrocarbon oxidation rate was calculated (see Table 1).

[0050] Example 4

[0051] Prepare a solubilizer solution: Prepare a solution containing alkaline protease, fatty acid potassium soap, and sodium lauryl sulfate in a mass ratio of 0.8:1:1, with water as the solvent. Adjust the pH of the solubilizer solution to 10 with sodium hydroxide. The concentration of the solubilizer solution is 20,000 mg / L. The alkaline protease activity is 4,000 U / mL, and the fatty acid potassium soap has 14 carbon atoms.

[0052] The concentration of petroleum hydrocarbons in the contaminated soil was 2000 mg / kg, consisting of linear alkanes. The petroleum hydrocarbon-contaminated soil and solubilizing agent solution were mixed at a mass ratio of 1:6. The mixture was then placed on a disk shaker at 60 rpm / min and room temperature (20°C) for 24 hours. The sample tube was then ultrasonically cleaned for 2 hours at 1000 W to obtain a mixture. The solubilization efficiency was determined according to the method in Example 1, as shown in Table 1.

[0053] Oxidation experiments were conducted by adding sodium persulfate according to the stoichiometric ratio. The amount of persulfate added was 0.6 g per gram of contaminated soil. The samples were then placed on a thermostatic shaker at 60°C for 160 hours. After centrifugation in a high-speed centrifuge and solid-liquid separation, the mass of petroleum hydrocarbons remaining in the soil after oxidation was measured, and the petroleum hydrocarbon oxidation rate was calculated (see Table 1).

[0054] Example 5

[0055] Prepare a solubilizer solution: Prepare a solution containing alkaline protease, fatty acid potassium soap, and sodium lauryl sulfate in a mass ratio of 1.2:1:1.5, with water as the solvent. Adjust the pH of the solubilizer solution to 9.5 with potassium hydroxide. The concentration of the solubilizer solution is 25,000 mg / L. The alkaline protease activity is 3,000 U / mL, and the fatty acid potassium soap has 18 carbon atoms.

[0056] The concentration of petroleum hydrocarbons in the contaminated soil was 2400 mg / kg, consisting of linear alkanes. The petroleum hydrocarbon-contaminated soil and solubilizing agent solution were mixed at a mass ratio of 1:4. The mixture was then placed on a disk shaker at 60 rpm / min and room temperature (20°C) for 28 hours. The sample tube was then ultrasonically cleaned for 2 hours at 1000 W to obtain a mixture. The solubilization efficiency was determined according to the method in Example 1, as shown in Table 1.

[0057] Oxidation experiments were conducted by adding sodium persulfate according to the stoichiometric ratio. The amount of persulfate added was 0.5 g per gram of contaminated soil. After the addition of sodium persulfate, the mixture was sonicated for 2 hours. The sample was then placed on a thermostatic shaker at 60°C for 180 hours of oxidation. After centrifugation in a high-speed centrifuge and solid-liquid separation, the mass of petroleum hydrocarbons remaining in the oxidized soil was measured, and the petroleum hydrocarbon oxidation rate was calculated (see Table 1).

[0058] Example 6

[0059] Prepare a solubilizer solution: Prepare a solution of alkaline protease, fatty acid potassium soap, and sodium lauryl sulfate in a mass ratio of 1:1:2, with water as the solvent. Adjust the pH of the solubilizer solution to 13 with potassium hydroxide. The concentration of the solubilizer solution is 25,000 mg / L. The alkaline protease activity is 5,000 U / mL, and the fatty acid potassium soap has 16 carbon atoms.

[0060] The concentration of petroleum hydrocarbons in the contaminated soil was 1800 mg / kg, consisting of linear alkanes. The petroleum hydrocarbon-contaminated soil and the solubilizer solution were mixed at a mass ratio of 1:5. The mixture was then placed on a disk shaker and allowed to react at 60 rpm / min at room temperature (20°C) for 24 hours to obtain a mixture. The solubilization efficiency was determined according to the method in Example 1, as shown in Table 1.

[0061] Oxidation experiments were conducted by adding sodium persulfate according to the stoichiometric ratio. The persulfate dosage was 0.5 g per gram of contaminated soil. The samples were then placed on a thermostatic shaker at 60°C for 120 hours. After centrifugation in a high-speed centrifuge and solid-liquid separation, the mass of petroleum hydrocarbons remaining in the oxidized soil was measured, and the petroleum hydrocarbon oxidation rate was calculated (see Table 1).

[0062] Example 7:

[0063] Prepare a solubilizer solution: Prepare a solution of alkaline protease, fatty acid potassium soap, and sodium lauryl sulfate in a mass ratio of 1:1:2, with water as the solvent. Adjust the pH of the solubilizer solution to 10 with calcium hydroxide. The concentration of the solubilizer solution is 25,000 mg / L. The alkaline protease activity is 5,000 U / mL, and the fatty acid potassium soap has 16 carbon atoms.

[0064] The concentration of petroleum hydrocarbons in the contaminated soil was 1800 mg / kg, consisting of linear alkanes. The petroleum hydrocarbon-contaminated soil and the solubilizer solution were mixed at a mass ratio of 1:5. The mixture was then placed on a disk shaker and allowed to react at 60 rpm / min at room temperature (20°C) for 24 hours to obtain a mixture. The solubilization efficiency was determined according to the method in Example 1, as shown in Table 1.

[0065] Sodium persulfate was added to the remaining unseparated mixture according to the stoichiometric ratio to conduct an oxidation experiment. The amount of persulfate added was 0.5 g per gram of contaminated soil. The sample was then placed on a thermostatic shaker at 60°C for 120 hours. After centrifugation in a high-speed centrifuge and solid-liquid separation, the mass of petroleum hydrocarbons remaining in the oxidized soil was measured, and the petroleum hydrocarbon oxidation rate was calculated (see Table 1).

[0066] Comparative Example 1

[0067] Prepare a solubilizer solution: Prepare a solution of fatty acid potassium soap and sodium lauryl sulfate in a mass ratio of 1:2, with water as the solvent. Adjust the pH of the solubilizer solution to 10 with potassium hydroxide. The concentration of the solubilizer solution is 25,000 mg / L. The fatty acid potassium soap has 16 carbon atoms.

[0068] The concentration of petroleum hydrocarbons in the contaminated soil was 1800 mg / kg, consisting of linear alkanes. The petroleum hydrocarbon-contaminated soil and the solubilizer solution were mixed at a mass ratio of 1:5. The mixture was then placed on a disk shaker and allowed to react at 60 rpm / min at room temperature (20°C) for 24 hours to obtain a mixture. The solubilization efficiency was determined according to the method in Example 1, as shown in Table 1.

[0069] Oxidation experiments were conducted by adding sodium persulfate according to the stoichiometric ratio. The persulfate dosage was 0.5 g per gram of contaminated soil. The samples were then placed on a thermostatic shaker at 60°C for 120 hours. After centrifugation in a high-speed centrifuge and solid-liquid separation, the mass of petroleum hydrocarbons remaining in the oxidized soil was measured, and the petroleum hydrocarbon oxidation rate was calculated (see Table 1).

[0070] Comparative Example 2

[0071] Prepare a solubilizer solution: Prepare a solution of alkaline protease and sodium lauryl sulfate in a mass ratio of 1:2, with water as the solvent. Adjust the pH of the solubilizer solution to 10 with potassium hydroxide. The concentration of the solubilizer solution is 25,000 mg / L. The enzymatic activity of the alkaline protease is 5,000 U / mL.

[0072] The concentration of petroleum hydrocarbons in the contaminated soil was 1800 mg / kg, consisting of linear alkanes. The petroleum hydrocarbon-contaminated soil and the solubilizer solution were mixed at a mass ratio of 1:5. The mixture was then placed on a disk shaker and allowed to react at 60 rpm / min at room temperature (20°C) for 24 hours to obtain a mixture. The solubilization efficiency was determined according to the method in Example 1, as shown in Table 1.

[0073] Oxidation experiments were conducted by adding sodium persulfate according to the stoichiometric ratio. The persulfate dosage was 0.5 g per gram of contaminated soil. The samples were then placed on a thermostatic shaker at 60°C for 120 hours. After centrifugation in a high-speed centrifuge and solid-liquid separation, the mass of petroleum hydrocarbons remaining in the oxidized soil was measured, and the petroleum hydrocarbon oxidation rate was calculated (see Table 1).

[0074] Comparative Example 3

[0075] Prepare the solubilizer solution: Prepare a 25,000 mg / L sodium lauryl sulfate solution. Adjust the pH of the solubilizer solution to 10 with potassium hydroxide.

[0076] The concentration of petroleum hydrocarbons in the contaminated soil was 1800 mg / kg, consisting of linear alkanes. The petroleum hydrocarbon-contaminated soil and the solubilizer solution were mixed at a mass ratio of 1:5. The mixture was then placed on a disk shaker and allowed to react at 60 rpm / min at room temperature (20°C) for 24 hours to obtain a mixture. The solubilization efficiency was determined according to the method in Example 1, as shown in Table 1.

[0077] Oxidation experiments were conducted by adding sodium persulfate according to the stoichiometric ratio. The persulfate dosage was 0.5 g per gram of contaminated soil. The samples were then placed on a thermostatic shaker at 60°C for 120 hours. After centrifugation in a high-speed centrifuge and solid-liquid separation, the mass of petroleum hydrocarbons remaining in the oxidized soil was measured, and the petroleum hydrocarbon oxidation rate was calculated (see Table 1).

[0078] Table 1

[0079] Solubilization rate (%) Oxidation rate (%) Example 1 89 92 Example 2 82 87 Example 3 79 84 Example 4 90 92 Example 5 90 91 Example 6 78 85 Example 7 83 86 Comparative Example 1 75 82 Comparative Example 2 77 83 Comparative Example 3 68 75

[0080] The above describes in detail the specific embodiments of the present invention, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as the contents disclosed by the present invention and fall within the scope of protection of the present invention.

Claims

1. A solubilizing agent comprising: Alkaline protease, fatty acid potassium soap, and sodium lauryl sulfate; the mass ratio of alkaline protease, fatty acid potassium soap, and sodium lauryl sulfate is (0.5-2):1:(0.5-3); the enzymatic activity of the alkaline protease is 500-6000 U / mL; the number of carbon atoms of the fatty acid potassium soap is C12-C20; and the pH of the solubilizer is 5-13.

2. The solubilizing agent according to claim 1, wherein In the solubilizer, the mass ratio of alkaline protease, fatty acid potassium soap, and sodium lauryl sulfate is (0.8-1.2):1:(1-2).

3. The solubilizing agent according to claim 1, characterized in that The pH of the solubilizer is 9~10.

4. The solubilizing agent according to claim 1, characterized in that The alkaline protease has an enzymatic activity of 3000-5000 U / mL.

5. The solubilizing agent according to claim 1, characterized in that The carbon number of the fatty acid potassium soap is C14~C18.

6. The solubilizing agent according to claim 1, characterized in that The solubilizing agent contains a pH regulator; the pH regulator is at least one of potassium hydroxide, sodium hydroxide, and calcium hydroxide.

7. The solubilizing agent according to claim 6, characterized in that The pH regulator is potassium hydroxide.

8. Use of the solubilizing agent according to any one of claims 1 to 7 in the oxidation remediation of petroleum hydrocarbon contaminated soil, characterized in that: The application method comprises the following steps: The solubilizing agent is added to petroleum hydrocarbon contaminated soil for solubilization treatment; then persulfate is added for oxidation treatment to obtain repaired soil.

9. The application according to claim 8, characterized in that: The solubilizer is in the form of a solution; the concentration of the solubilizer solution is 2000-40000 mg / L; and the mass ratio of the petroleum hydrocarbon-contaminated soil to the solubilizer solution is 1:2-1:

10.

10. The use according to claim 9, characterized in that: The solubilizer is in the form of a solution; the concentration of the solubilizer solution is 15,000 to 25,000 mg / L; and the mass ratio of the petroleum hydrocarbon-contaminated soil to the solubilizer solution is 1:4 to 1:

6.

11. The use according to claim 8, characterized in that: The solubilization treatment time is 2 to 40 hours; the oxidation treatment time is 1 to 240 hours.

12. The application according to claim 11, characterized in that: The solubilization treatment time is 20-30 h; the oxidation treatment time is 120-180 h.

13. The use according to claim 8, characterized in that: The persulfate is a soluble persulfate.

14. The use according to claim 13, characterized in that The persulfate is at least one of sodium persulfate, potassium persulfate and ammonium persulfate.

15. The use according to claim 8, characterized in that: The amount of persulfate added per gram of contaminated soil is 0.20~1.00 g.

16. The use according to claim 15, characterized in that The amount of persulfate added per gram of contaminated soil is 0.40~0.60g.

17. The use according to claim 8, characterized in that The petroleum hydrocarbons are hydrophobic organic pollutants; the concentration of petroleum hydrocarbons in contaminated soil is 800-4000 mg / kg.

18. The use according to claim 17, characterized in that: The petroleum hydrocarbons are hydrophobic organic pollutants; the concentration of petroleum hydrocarbons in contaminated soil is 1800-2400 mg / kg.

19. The use according to claim 8, characterized in that After adding the persulfate, the mixture is ultrasonicated and / or heated; the ultrasonication time is 1 to 6 hours; and the heating temperature is 30 to 80°C.

20. The use according to claim 19, characterized in that The ultrasonic time is 2-4 hours; the heating temperature is 50-60°C.