Viscosity-temperature compensation method for blocking migration of petroleum pollutants in soil based on source

Abstract

The invention is applicable to the technical field of petroleum-polluted soil treatment, and provides a viscosity-temperature compensation method for blocking migration of petroleum pollutants in soil based on a source, which comprises the following steps: extracting petroleum in soil, measuring asphaltene content, adjusting the water content parameter of polluted soil, adding a first modifier epoxidized acrylate (AESO), and uniformly stirring; adding a second modifier polymethacrylate (T602HB), uniformly stirring, continuing to add lime and fly ash, uniformly stirring, compacting and curing, and carrying out a wide-temperature-range simulated rainfall test. On one hand, a first modifier AESO and a second modifier T602HB are added according to the content of asphaltene in a grading manner to construct a composite active interface of'tackifying-viscosity reducing and combining ', so that the adsorption effect between soil particles and petroleum is enhanced, and on the other hand, the modifiers and lime-fly ash are added in a grading manner; the competitive adsorption phenomenon of the composite modifier is solved, and the compatibility problem of organic-inorganic materials is prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of treating oil-contaminated soil, and more specifically, to a viscosity-temperature compensation method for blocking the migration of petroleum pollutants in soil at the source. Background Technique

[0002] The viscosity-temperature property of petroleum affects the adsorption performance between the medium and petroleum, and is the key to inducing the dynamic evolution of petroleum pollutants in soil. Petroleum mainly includes oil, gum, asphaltene, and carbon. Asphaltene, as an important polar macromolecular component in petroleum, its content and structure have a decisive influence on the temperature sensitivity of petroleum. At high temperatures, the thermal motion of asphaltene increases, the micelle structure depolymerizes, and the network becomes loose, resulting in a decrease in the overall viscosity of petroleum molecules and an increase in its fluidity. At low temperatures, asphaltene forms a three-dimensional network through polar groups and aromatic ring structures, encapsulating oil and gum, greatly increasing the viscosity of petroleum. It is difficult to restore the network structure after destruction. Asphaltene dominates the temperature-sensitive behavior of petroleum through changes in molecular aggregation states, thereby affecting the dynamic desorption-adsorption behavior of petroleum molecules in contaminated soil. Lime-fly ash can improve the adsorption of petroleum pollutants in soil to a certain extent, but it has also been found that the transformation of the occurrence form of petroleum in soil caused by environmental temperature is the internal cause of the performance fluctuations of oil-contaminated soil. The desorption amount of petroleum still changes continuously with temperature fluctuations. The reasonable regulation of the viscosity-temperature property of oil-contaminated soil determines its stability and environmental safety during the engineering reuse process, and is the key scientific problem to be solved in promoting the engineering reuse of oil-contaminated soil.

[0003] Currently, there are two major defects in the treatment of oil-contaminated soil: poor adaptability within a wide temperature range and insufficient two-way stability of petroleum-soil particles. Traditional single modification methods cannot meet the requirements of high-temperature viscosity increase and low-temperature fluidity, and lime-fly ash has limitations in suppressing the temperature sensitivity of asphaltene, resulting in secondary migration of petroleum pollutants. Therefore, based on the above problems, a viscosity-temperature compensation method for blocking the migration of petroleum pollutants in soil at the source is proposed to construct a complex structure system of hierarchical and staged-synergistic solidification. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a viscosity-temperature compensation method for blocking the migration of petroleum pollutants in soil at the source to solve the phenomenon of competitive adsorption of composite modifiers and prevent the compatibility problem between organic and inorganic materials.

[0005] To achieve the above purpose, the present invention provides the following technical solutions: A viscosity-temperature compensation method for blocking the migration of petroleum pollutants in soil at the source, comprising the following steps: Step S1, extract petroleum in the soil and determine the asphaltene content; Step S2, adjust the moisture content parameter of the contaminated soil; Step S3: Add the first modifier, epoxidized acrylate (AESO), and stir evenly. Step S4: Add the second modifier, polymethacrylate (T602HB), and stir evenly. Step S5: Continuously add lime and fly ash and stir evenly. Step S6: Compactly cure and conduct a wide-temperature-range simulated rainfall test.

[0006] The present invention is further configured such that in the step S1, the asphaltene content in the petroleum is measured according to the solvent precipitation method, which is beneficial to dynamically regulating the dosing ratio of the modifier and achieving precise viscosity-temperature compensation.

[0007] The present invention is further configured such that in the step S2, the water content of the petroleum-contaminated soil is controlled to be 17.7%, and after stirring evenly, it is sealed and cured at room temperature for 24 hours to achieve the oil-water competitive adsorption equilibrium.

[0008] The present invention is further configured such that in the step S3, the first modifier, epoxidized acrylate soybean oil (AESO), is added according to 12% of the asphaltene content. After mixing and stirring evenly, it is covered with a film and sealed and cured at room temperature for 24 hours, which is beneficial for AESO to fully contact with the petroleum pollutants, and through its epoxy groups to pre-crosslink with the asphaltene, enhancing the petroleum viscosity.

[0009] The present invention is further configured such that in the step S4, the second modifier, polymethacrylate (T602HB), is added according to 6% of the asphaltene content. After mixing and stirring evenly, it is covered with a film and sealed and cured at room temperature for 7 days.

[0010] The present invention is further configured such that in the step S5, lime and fly ash are added according to the petroleum pollution concentration. When the petroleum pollution concentration ≤ 60 mg / g, the addition amounts of lime and fly ash are 8% and 20% of the dry soil mass percentage; when the petroleum pollution concentration is 60 m / g - 90 mg / g, the addition amounts of lime and fly ash are 10% and 25% of the dry soil mass percentage; when the petroleum pollution concentration > 90 mg / g, the addition amounts of lime and fly ash are 12% and 25% of the dry soil mass percentage. After mixing and stirring evenly, it is compacted and cured in a constant temperature and humidity environment for 28 days.

[0011] The present invention is further configured such that in the step S6, the petroleum-contaminated soil containing the first modifier, the second modifier, lime, and fly ash is compacted and cured, and a wide-temperature-range simulated rainfall test is conducted to determine the blocking effect.

[0012] The advantages of the present invention are: The present invention uses a method of hierarchical and staged - collaborative curing. On the one hand, the first modifier AESO and the second modifier T602HB are added in stages according to the asphaltene content to construct a "viscosity - increasing and viscosity - decreasing" composite active interface, enhancing the adsorption effect between soil particles and petroleum. On the other hand, the modifier, lime, and fly ash are added in stages to solve the phenomenon of competitive adsorption of the composite modifier and prevent the problem of the compatibility of organic - inorganic materials, enabling the polluted soil to meet the standards for road and traffic construction land (category II land) in the "Soil Environmental Quality - Risk Control Standards for Soil Pollution of Construction Land" (GB36600 - 2018) after remediation and can be directly reused as subgrade materials. The first modifier, epoxidized acrylate soybean oil (AESO), the second modifier, polymethacrylate (T602HB), lime, and fly ash have the advantages of low price, easy availability, and environmental friendliness, avoiding high operating costs and meeting the current engineering implementation prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a flowchart of the viscosity - temperature compensation method for blocking the migration of petroleum pollutants in soil at the source according to the present invention; Figure 2 is a distribution diagram of the oil content in the filtered polluted soil under different treatment methods according to the present invention; Figure 3 is a comparison diagram of the phenomena of the filtrate of the polluted soil under different treatment methods according to the present invention; Figure 4 is a comparison diagram of the phenomena of the filtrate of the solidified polluted soil under different treatment methods according to the present invention; Figure 5 is a microscopic comparison diagram of the polluted soil under different treatment methods according to the present invention; Figure 6 is a microscopic comparison diagram of the solidified polluted soil under different treatment methods according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] The following further elaborates the present application in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only for explaining the relevant invention and not for limiting the invention. Additionally, it should be noted that for ease of description, only parts related to the invention are shown in the drawings.

[0015] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will elaborate on the present application in detail with reference to the drawings and embodiments.

[0016] Please refer to Figure 1-6 , the present invention provides the following technical solutions: Specifically, it refers to a viscosity - temperature compensation method for blocking the migration of petroleum pollutants in soil at the source, and the specific operation steps are as follows: In this experiment, three types of contaminated soils with different petroleum concentrations were selected, and the petroleum concentrations in the contaminated soils were controlled at 30 mg / g, 90 mg / g, and 150 mg / g. Corresponding control groups were set for the petroleum-contaminated soils with different contamination concentrations.

[0017] Example 1 To ensure accurate viscosity compensation, the asphaltene content in petroleum was determined according to the solvent precipitation method. An appropriate amount of dry soil was taken, and the water content of the contaminated soil was controlled at 17.7% of the dry soil mass percentage. After stirring evenly, it was sealed and cured at room temperature for 24 hours with a film covering. According to the dry soil mass percentage, the petroleum concentration in the contaminated soil was controlled at 30 mg / g. To achieve the actual contaminated environment, the petroleum-contaminated soil was sealed and stored for 24 hours after preparation.

[0018] The first modifier, epoxidized acrylate soybean oil (AESO), was added at 12% of the asphaltene content. After mixing and stirring evenly, it was sealed and cured at room temperature for 24 hours with a film covering, and then 6% of the second modifier, polymethacrylate (T602HB), was added. After mixing and stirring evenly, it was sealed and cured at room temperature for 7 days to allow the modifier to fully contact with the petroleum.

[0019] According to the dry soil mass percentage, the ratio of lime to fly ash was controlled at 8% and 20%. After stirring evenly, it was cured in a constant temperature and humidity environment. The curing temperature was 20 ± 2°C, the curing humidity was ≥90%, and the curing age was 28 days.

[0020] Specific operation for making the soil column: Using a mold, the soil sample was compacted with a manual light compaction instrument. The cured soil sample was filled into the column body, and the cured samples were subjected to a wide-temperature-range simulated rainfall test at 0°C, 20°C, 40°C, 60°C, and 80°C. The column body was made of stainless steel, with a total height of 230 mm and an inner diameter of 70 mm.

[0021] Example 2 To ensure accurate viscosity compensation, the asphaltene content in petroleum was determined according to the solvent precipitation method. An appropriate amount of dry soil was taken, and the water content of the contaminated soil was controlled at 17.7% of the dry soil mass percentage. After stirring evenly, it was sealed and cured at room temperature for 24 hours with a film covering. According to the dry soil mass percentage, the petroleum concentration in the contaminated soil was controlled at 90 mg / g. To achieve the actual contaminated environment, the petroleum-contaminated soil was sealed and stored for 24 hours after preparation.

[0022] According to the dry soil mass percentage, the ratio of lime to fly ash was controlled at 10% and 25%. After stirring evenly, it was cured in a constant temperature and humidity environment. The curing temperature was 20 ± 2°C, the curing humidity was ≥90%, and the curing age was 28 days.

[0023] The remaining steps were the same as those in Example 1.

[0024] Example 3 To ensure accurate viscosity compensation, the asphaltene content in petroleum is determined by the solvent precipitation method. Take an appropriate amount of dry soil, control the moisture content of the contaminated soil to be 17.7% of the dry soil mass percentage. After stirring evenly, cover it with a film and seal it for curing at room temperature for 24 hours. According to the dry soil mass percentage, control the petroleum concentration in the contaminated soil to be 150 mg / g. To achieve the actual contaminated environment, after preparation, the petroleum-contaminated soil is sealed and stored for 24 hours.

[0025] According to the dry soil mass percentage, control the ratio of lime to fly ash to be 12% and 25%. After stirring evenly, cure it in a constant temperature and humidity environment. The curing temperature is 20 ± 2 °C, the curing humidity is ≥ 90%, and the curing age is 28 days.

[0026] The remaining steps are the same as those in Example 1.

[0027] Comparative Example 1 Take an appropriate amount of dry soil, control the moisture content of the contaminated soil to be 17.7% of the dry soil mass percentage. After stirring evenly, cover it with a film and seal it for curing at room temperature for 24 hours. According to the dry soil mass percentage, control the petroleum concentration in the contaminated soil to be 30 mg / g. To achieve the actual contaminated environment, after preparation, the petroleum-contaminated soil is sealed and stored for 24 hours.

[0028] Specific operation for making the soil column: Use a mold and compact the soil sample with a manual light compaction instrument. Fill the cured soil sample into the column body. The cured samples are subjected to a wide-temperature range simulated rainfall test at 0 °C, 20 °C, 40 °C, 60 °C, and 80 °C. The column body is made of stainless steel, with a total height of 230 mm and an inner diameter of 70 mm.

[0029] Comparative Example 2 Take an appropriate amount of dry soil, control the moisture content of the contaminated soil to be 17.7% of the dry soil mass percentage. After stirring evenly, cover it with a film and seal it for curing at room temperature for 24 hours. According to the dry soil mass percentage, control the petroleum concentration in the contaminated soil to be 90 mg / g. To achieve the actual contaminated environment, after preparation, the petroleum-contaminated soil is sealed and stored for 24 hours.

[0030] The remaining steps are the same as those in Comparative Example 1.

[0031] Comparative Example 3 According to the dry soil mass percentage, control the petroleum concentration in the contaminated soil to be 150 mg / g. The remaining steps are the same as those in Comparative Example 1.

[0032] Comparative Example 4 To ensure accurate viscosity compensation, the asphaltene content in petroleum was determined according to the solvent precipitation method. An appropriate amount of dry soil was taken, and the water content of the contaminated soil was controlled at 17.7% of the dry soil mass percentage. After stirring evenly, it was sealed and cured at room temperature for 24 hours with a film. According to the dry soil mass percentage, the petroleum concentration in the contaminated soil was controlled at 30 mg / g. To achieve the actual contaminated environment, the petroleum-contaminated soil was sealed and stored for 24 hours after preparation.

[0033] The first modifier, epoxidized acrylate soybean oil (AESO), was added at 12% of the asphaltene content. After mixing and stirring evenly, it was sealed and cured at room temperature for 24 hours with a film, and then 6% of the second modifier, polymethacrylate (T602HB), was added. After mixing and stirring evenly, it was sealed and cured at room temperature for 7 days to allow the modifier to fully contact with the petroleum.

[0034] Specific operation for making the soil column: Using a mold, the soil sample was compacted with a manual light compaction instrument. The cured soil sample was filled into the column body, and the cured samples were subjected to a wide-temperature-range simulated rainfall test at 0 °C, 20 °C, 40 °C, 60 °C, and 80 °C. The column body was made of stainless steel, with a total height of 230 mm and an inner diameter of 70 mm.

[0035] Comparative Example 5 To ensure accurate viscosity compensation, the asphaltene content in petroleum was determined according to the solvent precipitation method. An appropriate amount of dry soil was taken, and the water content of the contaminated soil was controlled at 17.7% of the dry soil mass percentage. After stirring evenly, it was sealed and cured at room temperature for 24 hours with a film. According to the dry soil mass percentage, the petroleum concentration in the contaminated soil was controlled at 90 mg / g. To achieve the actual contaminated environment, the petroleum-contaminated soil was sealed and stored for 24 hours after preparation.

[0036] The remaining steps were the same as those in Comparative Example 4.

[0037] Comparative Example 6 According to the dry soil mass percentage, the petroleum concentration in the contaminated soil was controlled at 150 mg / g, and the remaining steps were the same as those in Comparative Example 4.

[0038] Comparative Example 7 An appropriate amount of dry soil was taken, and the water content of the contaminated soil was controlled at 17.7% of the dry soil mass percentage. After stirring evenly, it was sealed and cured at room temperature for 24 hours with a film. According to the dry soil mass percentage, the petroleum concentration in the contaminated soil was controlled at 30 mg / g. To achieve the actual contaminated environment, the petroleum-contaminated soil was sealed and stored for 24 hours after preparation.

[0039] According to the dry soil mass percentage, the ratio of lime to fly ash was controlled at 8% and 20%. After stirring evenly, it was cured in a constant-temperature and constant-humidity environment. The curing temperature was 20 ± 2 °C, the curing humidity was ≥ 90%, and the curing age was 28 days.

[0040] Specific operation of soil column production: Using a mold, compact the soil sample with a manual light compactor. Fill the cured soil sample into the column. The cured samples are subjected to a wide-temperature-range simulated rainfall test at 0°C, 20°C, 40°C, 60°C, and 80°C respectively. The column is made of stainless steel, with a total height of 230 mm and an inner diameter of 70 mm.

[0041] Comparative Example 8 Take an appropriate amount of dry soil, control the water content of the contaminated soil to be 17.7% of the dry soil mass percentage. After stirring evenly, cover it with a film and seal it for curing at room temperature for 24 hours. According to the dry soil mass percentage, control the petroleum concentration in the contaminated soil to be 90 mg / g. To achieve the actual contaminated environment, seal and store the petroleum-contaminated soil for 24 hours after preparation.

[0042] According to the dry soil mass percentage, control the ratio of lime to fly ash to be 10% and 25%. After stirring evenly, cure it in a constant temperature and humidity environment. The curing temperature is 20 ± 2°C, the curing humidity is ≥ 90%, and the curing age is 28 days.

[0043] The remaining steps are the same as those in Comparative Example 7.

[0044] Comparative Example 9 Take an appropriate amount of dry soil, control the water content of the contaminated soil to be 17.7% of the dry soil mass percentage. After stirring evenly, cover it with a film and seal it for curing at room temperature for 24 hours. According to the dry soil mass percentage, control the petroleum concentration in the contaminated soil to be 150 mg / g. To achieve the actual contaminated environment, seal and store the petroleum-contaminated soil for 24 hours after preparation.

[0045] According to the dry soil mass percentage, control the ratio of lime to fly ash to be 12% and 25%. After stirring evenly, cure it in a constant temperature and humidity environment. The curing temperature is 20 ± 2°C, the curing humidity is ≥ 90%, and the curing age is 28 days.

[0046] The remaining steps are the same as those in Comparative Example 7.

[0047] Such as Figure 2As shown by the comparison, the maximum volatility rates of the oil-contaminated soil compared to the initial oil content are as high as 75%, 83.59%, and 84.03% respectively; the oil content after filtration of the modified oil-contaminated soil at each temperature is between that of the oil-contaminated soil and the solidified oil-contaminated soil. In terms of improving the temperature sensitivity of asphaltene, its effect is lower than that of the solidification effect of lime fly ash; at high temperatures, the volatility rate of the solidified oil-contaminated soil is as high as 57%; the modifier in combination with lime fly ash significantly improves the temperature sensitivity of asphaltene, making the overall solidified oil-contaminated soil less affected by temperature. The oil content after filtration within the studied temperature range is always close to the initial oil content, and the change rate compared to the initial oil content is 0.79% - 4.19%, meeting the standards for road and traffic construction land (category II land) in the "Soil Environmental Quality - Risk Control Standards for Soil Pollution of Construction Land" (GB36600 - 2018).

[0048] As Figure 3 As shown by the comparison Figure 4 As shown, a thick oil layer was observed in the oil-contaminated soil within a wide temperature range; the oil content concentration and filtrate clarity of the modified oil-contaminated soil were improved compared to the oil-contaminated soil. The regulation effect was the best at an environmental temperature of 60°C, but there was still an obvious oil layer. Even the filtration phenomenon was aggravated under the working condition of 80°C. Although the modifier could passivate the viscosity-temperature property of asphaltene to a certain extent, it was not effective in strengthening the adsorption stability of oil in the soil; in the high-temperature stage (>40°C), the effects of both lime and fly ash were not ideal. Combining Figure 3 with the data shown, the desorption performance of petroleum pollutants in the solidified oil-contaminated soil was still positively correlated with temperature; the filtrate of the solidified oil-contaminated soil with the modifier in combination with lime fly ash was always clear under all studied working conditions, confirming that the synergistic solidification effect of the modifier and lime fly ash could enhance the adsorption stability of petroleum pollutants in the soil, solve the influence of temperature on its desorption performance, and achieve the risk of blocking the migration and diffusion of petroleum pollutants in the soil from the source.

[0049] As Figure 5As shown by the comparison, the distribution of oil in soil under the action of temperature is closely related to the thermosensitivity of the asphaltenes contained. At low temperatures (≤20°C), the asphaltene molecular chains aggregate to form a three-dimensional crystal network, which encapsulates other oil components and increases the viscosity of the oil. The strongly bound oil increases, and the oil mostly exists in the form of irregular thick oil films on the surface and in the pores of soil particles. When the temperature rises (≥40°C), the thermal motion of asphaltenes increases, and the network structure loosens, resulting in a decrease in the viscosity of the oil and the disappearance of the thick oil film state. Along with the increase in the content of free and weakly bound states, the mobile oil is mostly distributed in the pores of the soil mass. The combined use of the two modifiers plays a viscosity-reducing role at low temperatures, and the modified oil mostly exists in the form of uniform thin oil films on the surface and in the pores of soil particles. Under high-temperature conditions (>60°C), although the modifier can play a certain viscosity-increasing role, its viscosity value still shows a downward trend overall, and the thin film is more susceptible to temperature than the thick oil film, resulting in a decrease in the clarity of the soil particle contour.

[0050] As Figure 6 As shown by the comparison, affected by the fluctuations in the thermosensitivity of asphaltenes, the morphology of the solidified product gradually changes from rod-shaped to flocculent. The free oil and flocculent products fill the pores of the soil mass. The change in the aggregation morphology of asphaltenes under the influence of temperature will affect the rheology of the oil, directly weakening the solidification effect of lime fly ash. This is exactly the reason for the limited regulation of lime fly ash. Epoxy acrylate soybean oil (AESO) and polymethacrylate (T602HB) are used in combination with lime-fly ash for the thermosensitivity treatment of oil-contaminated soil. Through the complementary and mutually promoting effects of the modifier and lime and fly ash in terms of viscosity-temperature compensation, the dynamic desorption-adsorption effect between the oil-soil interface is enhanced, forming a "viscosity-increasing and viscosity-reducing combined" composite structure, strengthening the persistence of the thin oil film state.

[0051] In this patent, with the help of osmosis, dispersion and other effects, the modifier enters the voids of the asphaltene structure. AESO, through its long functional group chain and abundant hydroxyl groups (-OH), fully extends in the pores of asphaltenes, plays a cross-linking role and encapsulates other oil components, enhancing the cohesion of asphaltenes, thereby increasing the viscosity of the oil in a high-temperature environment; T602HB forms a co-crystal with asphaltenes through its alkyl side chain, changes the crystal growth direction, and makes it form uniform and loose grains, which can prevent the asphaltene and aromatic ring structure from forming a three-dimensional space network, thereby reducing the viscosity of the oil in a low-temperature environment and ensuring the low-temperature fluidity of the oil product. The combined use of the two viscosity index improvers helps to achieve two-way viscosity-temperature compensation regulation for high and low temperatures, and further obtain the stability of the oil viscosity in a wide temperature range.

[0052] The above description is only a preferred embodiment of the present application and an explanation of the technical principles applied. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solutions formed by the specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the technical solutions formed by mutually replacing the above features with the technical features (but not limited to) disclosed in the present application that have similar functions.

Claims

1. A viscosity-temperature compensation method based on blocking the migration of petroleum pollutants in soil at the source, characterized by: The following steps are involved: Step S1, extracting petroleum from the soil and determining the asphaltene content; Step S2: adjusting the moisture content parameters of the contaminated soil; Step S3, adding the first modifier epoxidized acrylate (AESO) and stirring evenly; Step S4, adding the second modifier polymethacrylate (T602HB) and stirring evenly; Step S5: continue to add lime and fly ash and stir evenly; Step S6: compaction and maintenance, and conduct a wide temperature range simulated rainfall test.

2. The viscosity-temperature compensation method based on source blocking of petroleum pollutant migration in soil according to claim 1 is characterized in that: In the step S1, the asphaltene content in the petroleum is determined according to the solvent precipitation method, which is conducive to dynamically controlling the dosage ratio of the modifier and realizing accurate viscosity-temperature compensation.

3. The viscosity-temperature compensation method based on source blocking of petroleum pollutant migration in soil according to claim 1 is characterized in that: In the step S2, the moisture content of the petroleum contaminated soil is controlled to be 17.7%, and after being stirred evenly, the soil is sealed and cured at room temperature for 24 hours to achieve oil-water competitive adsorption equilibrium.

4. The viscosity-temperature compensation method based on source blocking of petroleum pollutant migration in soil according to claim 1 is characterized in that: In the step S3, the first modifier epoxidized acrylate soybean oil (AESO) is added according to the asphaltene content of 12%, and after being mixed and stirred evenly, the film is coated and sealed at room temperature for 24 hours, which is conducive to full contact between AESO and petroleum pollutants, and pre-crosslinking with asphaltene through its epoxy group to enhance the viscosity of petroleum.

5. The viscosity-temperature compensation method based on source blocking of petroleum pollutant migration in soil according to claim 1 is characterized in that: In the step S4, a second modifier, polymethacrylate (T602HB), is added according to 6% of the asphaltene content, and after mixing and stirring evenly, the mixture is coated and sealed at room temperature for 7 days.

6. The viscosity-temperature compensation method based on source blocking of petroleum pollutant migration in soil according to claim 1 is characterized in that: In the step S5, lime and fly ash are added according to the petroleum pollution concentration. When the petroleum pollution concentration is ≤60mg / g, the amount of lime and fly ash added is 8% and 20% of the dry soil mass percentage; when the petroleum pollution concentration is 60m / g-90mg / g, the amount of lime and fly ash added is 10% and 25% of the dry soil mass percentage; when the petroleum pollution concentration is greater than 90mg / g, the amount of lime and fly ash added is 12% and 25% of the dry soil mass percentage. The mixture is stirred evenly and then compacted, and cured for 28 days in a constant temperature and humidity environment.

7. The viscosity-temperature compensation method based on source blocking of petroleum pollutant migration in soil according to claim 1 is characterized in that: In the step S6, the petroleum contaminated soil containing the first modifier, the second modifier, lime and fly ash is compacted and cured, and a wide temperature range simulated rainfall test is carried out to determine the blocking effect.

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