Oil washing composition, preparation method and application thereof, and method for repairing heavy oil-contaminated soil

Abstract

The present invention relates to the technical field of soil contamination remediation in the petroleum and petrochemical industries, and discloses a detergent composition, its preparation method, and its application, as well as a method for remediating heavy oil-contaminated soil. The oil-washing composition contains the following components, either separately or in combination: an anionic sulfonate surfactant, a cyclodextrin, and water. The anionic sulfonate surfactant is a branched tail-chain anionic sulfonate surfactant having the structure represented by formula (I). The detergent composition provided by the present invention features low usage, high oil-washing efficiency, and easy biodegradation. Furthermore, the detergent composition provided by the present invention can be used to remediate heavy oil-contaminated soil, achieving efficient and green leaching of heavy oil contaminants. #imgabs0#

Description

Technical Field

[0001] The present invention relates to the technical field of soil pollution remediation in the petroleum and petrochemical industries, and in particular to an oil washing composition, a preparation method and application thereof, and a method for remediating heavy oil-contaminated soil. Background Art

[0002] In recent years, soil pollution in the petroleum and petrochemical industries has garnered significant attention. Due to factors such as company relocations, leakage from aging equipment, pipeline and tank leaks, illegal discharges, and sudden environmental incidents, the soil at various company sites is contaminated to varying degrees by petroleum. Furthermore, the remediation of aging, oil-contaminated soil left over from oilfields and the disposal of ground sludge, oil-containing sludge, and tank bottom mud collected by oilfield joint stations have become significant challenges.

[0003] Under the guidance of the concept of "ecological priority and green development", how to repair polluted sites and achieve green development is a key issue that needs to be urgently addressed.

[0004] Ex situ soil leaching is a mature soil remediation technology with the advantages of rapid results and simple process. However, soil contaminants from the petroleum and petrochemical industries are high in polycyclic aromatic hydrocarbons (PAHs). These PAHs have poor water solubility and strong adhesion to soil surfaces, making them ineffective for removal by traditional leaching agents.

[0005] Therefore, there is an urgent need to develop efficient green soil cleaning agents for PAHs-rich contaminated soils.

[0006] Soil detergents are usually oil-water amphiphilic surfactant molecules that rely on the following two mechanisms to clean crude oil from soil: (1) Curling mechanism. Surfactants gather in large quantities at the interface between soil and water and between oil and water, reducing the interfacial tension of the contact surface; at the same time, their adsorption at the interface produces a wetting reversal effect, which can wet the surface of soil and oil with water and increase the contact angle between soil and oil, thereby reducing the adsorption force of soil on oil, thereby stripping oil pollutants from the soil surface and migrating them into the water phase. (2) Solubilization mechanism. Surfactants form aggregates such as micelles and vesicles in water. The hydrophobic microregions inside the aggregates can solubilize oily pollutants with poor water solubility through the principle of like dissolves like, causing them to desorb from the surface of soil particles and disperse into the water phase.

[0007] CN112724981A discloses a petroleum-contaminated soil eluent composition, which is composed of a nonionic surfactant, an amphoteric surfactant, an alkaline substance, and water. It can significantly reduce the content of petroleum hydrocarbons in contaminated soil, ultimately achieving the purpose of soil remediation and utilization. However, the nonionic surfactant and the amphoteric surfactant, as the two main components of the eluent composition, are both weakly positively charged and have a large adsorption capacity in the soil, which may lead to increased agent costs and large retention. Therefore, the scope of application of the eluent composition provided by this technology is limited.

[0008] CN110404952A discloses a leaching agent for repairing contaminated soil, which contains the following components: 50 to 70 parts by weight of a non-ionic biosurfactant and 5 to 30 parts by weight of an anionic surfactant. Through the synergistic combination of non-ionic biosurfactants and anionic surfactants, the solubilization effect of the leaching agent on soil organic pollutants, especially polycyclic aromatic hydrocarbons, is enhanced, and the elution efficiency of the leaching agent is significantly improved. However, the system must be foamed before use to improve the sweep efficiency of the leaching agent in the soil medium. On the one hand, the foaming process is relatively time-consuming and labor-intensive; on the other hand, in order to give full play to the function of the foam, the foam of the system is required to be as much and as stable as possible. However, after the elution is completed, the treatment of the remaining foam is also relatively cumbersome. Summary of the Invention

[0009] The purpose of the present invention is to overcome the problems of low elution efficiency, environmental pollution and complex operation in the prior art, and to provide a lotion composition for repairing heavy oil-contaminated soil. The lotion composition has the characteristics of low dosage, high oil washing efficiency and easy biodegradation.

[0010] To achieve the above-mentioned object, the first aspect of the present invention provides an oil washing composition for remediating heavy oil-contaminated soil, wherein the oil washing composition comprises the following components, which are stored separately or in combination: an anionic sulfonate surfactant, cyclodextrin, and water;

[0011] The anionic sulfonate surfactant is a branched tail chain anionic sulfonate surfactant having a structure shown in formula (I).

[0012]

[0013] In formula (I), M is Na, K, Li or NH4.

[0014] The second aspect of the present invention provides a method for preparing the washing oil composition of the first aspect, the method comprising: mixing an anionic sulfonate surfactant, cyclodextrin and water;

[0015] The definition of the anionic sulfonate surfactant is the same as that described in the first aspect.

[0016] The third aspect of the present invention provides use of the oil washing composition described in the first aspect in remediating heavy oil-contaminated soil.

[0017] A fourth aspect of the present invention provides a method for remediating heavy oil-contaminated soil, the method comprising:

[0018] (1) contacting and eluting the oil washing composition described in the first aspect with heavy oil-contaminated soil to obtain a mixture I;

[0019] (2) subjecting the mixture I to solid-liquid separation.

[0020] The oil-washing composition provided by the present invention for remediating heavy oil-contaminated soil improves the efficiency of leaching pollutants from heavy oil-contaminated soil through the synergistic effect of branched tail-chain anionic sulfonates and cyclodextrins. Furthermore, both main components of the wash composition are readily biodegradable, resulting in low residual amounts in the soil and preventing secondary pollution. Therefore, the method provided by the present invention for remediating heavy oil-contaminated soil is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a multi-branched tail chain anionic sodium sulfonate surfactant BC prepared in the preparation example of the present invention. 16 ESI mass spectrum of SO3Na. DETAILED DESCRIPTION

[0022] The endpoints of the ranges and any values disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0023] As mentioned above, the first aspect of the present invention provides an oil washing composition for remediating heavy oil-contaminated soil, wherein the oil washing composition comprises the following components, which are stored separately or in combination: an anionic sulfonate surfactant, cyclodextrin, and water;

[0024] The anionic sulfonate surfactant is a branched tail chain anionic sulfonate surfactant having a structure shown in formula (I).

[0025]

[0026] In formula (I), M is Na, K, Li or NH4.

[0027] Preferably, in formula (I), M is Na, K or NH4.

[0028] More preferably, in formula (I), M is Na.

[0029] The present invention has no particular limitation on the method for preparing the branched tail chain anionic sulfonate surfactant. However, in order to achieve better results, the present invention preferably provides the following method for preparing the anionic sulfonate surfactant.

[0030] According to a preferred embodiment, the present invention provides a method for preparing a branched tail chain anionic sulfonate surfactant, the method comprising:

[0031] (1) contacting a quaternary olefin represented by formula (I-1), acrylonitrile, and a sulfonating agent to obtain a mixture I;

[0032] (2) using an alkaline substance containing the element M to adjust the pH value of the mixture I to be greater than or equal to 7;

[0033]

[0034] In the alkaline substance, the definition of M is the same as that in the first aspect.

[0035] More preferably, the method for preparing anionic sulfonate surfactant is carried out under normal pressure.

[0036] More preferably, the sulfonating agent is at least one selected from chlorosulfonic acid, aminosulfonic acid, fuming sulfuric acid, and sulfur trioxide.

[0037] Preferably, the molar ratio of the stacked olefin, the acrylonitrile, and the sulfonating agent is 1:(0.5-5):(1-10). More preferably, the molar ratio of the stacked olefin, the acrylonitrile, and the sulfonating agent is 1:(1-2):(1-2).

[0038] Preferably, the conditions for the contact reaction at least meet the following requirements: temperature of 0-40° C. and time of 0.5-12 h; more preferably, the conditions for the contact reaction at least meet the following requirements: temperature of 15-30° C. and time of 4-8 h.

[0039] Preferably, an alkaline substance is used to adjust the pH value of the mixture I.

[0040] Preferably, the alkaline substance is selected from at least one of lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, ammonia water and ammonium carbonate.

[0041] The method for preparing the anionic sulfonate surfactant described in the first aspect is preferably carried out under stirring. There is no particular requirement for the stirring speed, and the method can be carried out using parameters known in the art.

[0042] Preferably, the route of the preparation method of the present invention is as follows:

[0043]

[0044] The superposed olefin raw material with a specific number of carbon atoms can be obtained by cutting the superposition process product into components. The acrylonitrile, sulfonating agent and base used in the present invention can be commercially available chemical reagents or can be prepared according to methods known in the art.

[0045] The preparation method of the anionic sulfonate surfactant is to use industrial superposed olefin as raw material, supplemented with acrylonitrile, and prepare the branched tail chain anionic sulfonate surfactant through a two-step one-pot process of sulfonation and acid-base neutralization.

[0046] The preparation method provided by the present invention is characterized in that the superposed olefin, acrylonitrile and sulfonating agent are reacted in proportion in one pot at room temperature and pressure to obtain an intermediate, and then the final product is prepared through acid-base neutralization reaction.

[0047] Preferably, the cyclodextrin is at least one selected from α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin.

[0048] In order to further improve the elution efficiency of the oil washing composition for heavy oil pollutants and enhance the stripping and dispersion of oil from the soil surface, more preferably, the cyclodextrin is β-cyclodextrin and / or γ-cyclodextrin.

[0049] Preferably, in the first aspect of the present invention, based on the total weight of the washing oil composition, the content of the anionic sulfonate surfactant is 0.5-1 wt%, the content of the cyclodextrin is 0.1-0.5 wt%, and the content of water is 98.5-99.4 wt%.

[0050] More preferably, the content of the anionic sulfonate surfactant is 0.8-1 wt %, the content of the cyclodextrin is 0.3-0.5 wt %, and the content of water is 98.5-98.9 wt %.

[0051] As mentioned above, the second aspect of the present invention provides a method for preparing the washing oil composition described in the first aspect, the method comprising: mixing an anionic sulfonate surfactant, cyclodextrin and water.

[0052] The definition of the anionic sulfonate surfactant is the same as that described in the first aspect, and will not be further described in the second aspect of the present invention. Those skilled in the art should not interpret this as a limitation to the present invention.

[0053] In the second aspect of the present invention, preferably, the cyclodextrin is at least one selected from α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin.

[0054] More preferably, the cyclodextrin is β-cyclodextrin and / or γ-cyclodextrin.

[0055] Preferably, in the second aspect of the present invention, based on the total weight of the anionic sulfonate surfactant, the cyclodextrin and the water, the amount of the anionic sulfonate surfactant is 0.5-1wt%, the amount of the cyclodextrin is 0.1-0.5wt%, and the amount of the water is 98.5-99.4wt%.

[0056] More preferably, the amount of the anionic sulfonate surfactant is 0.8-1 wt%, the amount of the cyclodextrin is 0.3-0.5 wt%, and the amount of water is 98.5-98.9 wt%.

[0057] Preferably, the mixing conditions at least meet the following conditions: temperature of 15-40° C., stirring speed of 300-800 rpm, and stirring time of 10-30 min.

[0058] The water described in the present invention can be deionized water, tap water, etc., and there is no special requirement for this.

[0059] As mentioned above, the third aspect of the present invention provides the use of the oil washing composition described in the first aspect in remediating heavy oil-contaminated soil.

[0060] The oil washing composition provided by the present invention has a good application effect on heavy oil-contaminated soil with a hydrocarbon oil content greater than or equal to 5wt%, and its oil washing efficiency is above 80%.

[0061] As mentioned above, the fourth aspect of the present invention provides a method for remediating heavy oil-contaminated soil, the method comprising:

[0062] (1) contacting and eluting the oil washing composition described in the first aspect with heavy oil-contaminated soil to obtain a mixture I;

[0063] (2) subjecting the mixture I to solid-liquid separation.

[0064] Preferably, in step (1), the contact elution conditions at least meet the following conditions: temperature of 25 to 80° C., and time of 1 to 6 hours.

[0065] More preferably, the contact elution conditions at least meet the following requirements: temperature of 40-60° C. and time of 2-4 hours.

[0066] Preferably, the weight ratio of the oil washing composition to the heavy oil contaminated soil is 3:1 to 10:1.

[0067] In order to further improve the elution efficiency of the oil washing composition, more preferably, the weight ratio of the oil washing composition to the heavy oil contaminated soil is 3:1 to 6:1.

[0068] Preferably, in the fourth aspect of the present invention, the hydrocarbon oil content in the heavy oil-contaminated soil is greater than or equal to 5 wt%.

[0069] The method for repairing heavy oil-contaminated soil provided by the present invention is green and environmentally friendly, with a simple process. The two main components of the oil washing composition used are non-toxic and easily biodegradable, and will not cause secondary pollution.

[0070] The present invention will be described in detail below through examples. In the following examples, all the reagents used are commercially available chemical reagents, as shown in Table 1.

[0071] Unless otherwise specified, the hydrocarbon oil content in the soil of the present invention is calculated by weight.

[0072] The main raw materials used in the preparation examples, embodiments and comparative examples are shown in Table 1.

[0073] Table 1

[0074] Product Name abbreviation source purity <![CDATA[C 16 Polyolefins - The laminated product is obtained by cutting the components 95％ Acrylonitrile - Braingwei AR Chlorosulfonic acid - Sinopharm >98％ Sodium hydroxide - Sinopharm >99％ α-cyclodextrin - Aladdin >99％ β-cyclodextrin - Aladdin >99％ γ-cyclodextrin - Aladdin >98％ Sodium α-olefin sulfonate AOS Zhejiang Jielang >98％

[0075] Preparation Example 1

[0076] C-based 16 Branched tail chain anionic sulfonate surfactant BC 16 Preparation of SO3Na:

[0077] Weigh C 16 22.4 g of superposed olefin was placed in a reaction flask, 10.6 g of acrylonitrile was added and stirred evenly. Then, 23.3 g of chlorosulfonic acid was weighed into a dropping funnel and added dropwise to the reaction flask while stirring. After the addition of chlorosulfonic acid, stirring was continued and the reaction was carried out at 25 ° C and normal pressure for 8 h. Subsequently, 8 g of sodium hydroxide was weighed, dissolved in 50 ml of water, and added to the reaction system several times until the pH value of the system was 9, thus obtaining the product BC. 16 SO3Na.

[0078] BC 16 After the SO3Na product system was freeze-dried, the product was characterized by ESI-MS. Figure 1As shown, the product system contains 374.3049 ((M-Na) - ) has the highest peak value, which is BC 16 The molecular ion peak of SO3Na proves that the product was successfully prepared.

[0079] In the following examples and comparative examples, the heavy oil-contaminated soil used was prepared according to the following steps:

[0080] 5000g of uncontaminated soil (from the Henan Oilfield) was pulverized and dried in a 150°C thermostat for 6 hours. The dried soil was then screened using a 100-mesh sieve. The sieved soil and crude oil were then placed in separate thermostats at 80°C for 8 hours. 95g of the dried soil was then mixed with 5g of heavy oil (density 0.922g / mL) from the Henan Oilfield and allowed to mix at 80°C. The soil-crude oil mixture was then aged in a 50°C thermostat for one week to produce an oil-containing soil sample with an oil content of 5wt%.

[0081] The calculation formulas for the oil removal rate and residual oil content of the oil washing composition are as follows:

[0082] Oil removal rate of oil-containing soil = ρV / (0.5g)*100%

[0083] Residual oil content in soil after cleaning = (0.5g-ρV) / m*100%

[0084] Where:

[0085] ρ is the density of crude oil, which is 0.922 g / mL;

[0086] V is the volume of crude oil read after liquid-solid separation, mL;

[0087] m is the mass of oil-containing soil after liquid-solid separation, g.

[0088] Example 1

[0089] At 35 ° C and 500 rpm, 1g of branched tail chain anionic sodium sulfonate surfactant BC 16 SO3Na and 0.5g of β-cyclodextrin were added to 98.5g of water and stirred for 15 minutes until completely dissolved to obtain a cleaning oil composition.

[0090] Methods for remediating heavy oil contaminated soil:

[0091] (1) Weigh 10 g of oil-containing soil, add 60 g of the oil-washing composition into a conical flask, place it in a shaker, heat it to 60°C, and shake it at a constant speed for 4 hours.

[0092] (2) The mixture of the oil-containing soil and the oil-washing composition was allowed to stand and settle, and the upper solution was removed and transferred to a graduated centrifuge tube. The mixture was centrifuged at 6000 rpm, and the volume of the separated oil (V) was read as 0.49 mL. The lower solid was dried and weighed.

[0093] The oil washing efficiency of Example 1 was obtained by calculation formula to be 90.4%, and the residual oil content in the soil was 0.51%.

[0094] Example 2

[0095] At 20 ° C and 500 rpm, 1g of branched tail chain anionic sodium sulfonate surfactant BC 16 SO3Na and 0.1 g of γ-cyclodextrin were added to 98.9 g of water and stirred for 30 minutes until completely dissolved to obtain a cleaning oil composition.

[0096] Methods for remediating heavy oil contaminated soil:

[0097] (1) Weigh 10 g of oil-containing soil, add 30 g of the oil-washing composition into a conical flask, place it in a shaker, heat it to 60°C, and shake it at a constant speed for 4 hours.

[0098] (2) The mixture of the oil-containing soil and the oil-washing composition was allowed to stand and settle, and the upper solution was removed and transferred to a graduated centrifuge tube. The mixture was centrifuged at 6000 rpm, and the volume of the separated oil (V) was read as 0.47 mL. The lower solid was dried and weighed.

[0099] The oil washing efficiency of Example 2 was obtained by calculation formula to be 86.7%, and the residual oil content in the soil was 0.70%.

[0100] Example 3

[0101] At 25 ° C and 500 rpm, 0.5 g of branched tail chain anionic sodium sulfonate surfactant BC 16 SO3Na and 0.5g of β-cyclodextrin were added to 99g of water and stirred for 20min until completely dissolved to obtain a cleaning oil composition.

[0102] Methods for remediating heavy oil contaminated soil:

[0103] (1) Weigh 10 g of oil-containing soil, add 60 g of high-efficiency oil washing system into a conical flask, place it in a shaker, heat it to 40°C, and shake it at a constant speed for 6 hours.

[0104] (2) The mixture of the oil-containing soil and the oil-washing composition was allowed to stand and settle, and the upper solution was removed and transferred to a graduated centrifuge tube. The mixture was centrifuged at 6000 rpm, and the volume of the separated oil (V) was read as 0.46 mL. The lower solid was dried and weighed.

[0105] The oil washing efficiency of Example 3 was obtained by calculation formula to be 84.8%, and the residual oil content in the soil was 0.79%.

[0106] Example 4

[0107] At 30 ° C and 500 rpm, 1g of branched tail chain anionic sodium sulfonate surfactant BC 16 SO3Na and 0.3g of β-cyclodextrin were added to 98.7g of water and stirred for 20min until completely dissolved to obtain a cleaning oil composition.

[0108] Methods for remediating heavy oil contaminated soil:

[0109] (1) Weigh 10 g of oil-containing soil, add 40 g of the oil-washing composition into a conical flask, place it in a shaker, heat it to 50°C, and shake it at a constant speed for 5 hours.

[0110] (2) The mixture of the oil-containing soil and the oil-washing composition was allowed to stand and settle, and the upper solution was taken out and transferred to a graduated centrifuge tube. The mixture was centrifuged at 6000 rpm, and the volume of the separated oil (V) was read as 0.45 mL. The lower solid was dried and weighed.

[0111] The oil washing efficiency of Example 4 was obtained by calculation formula to be 82.98%, and the residual oil content in the soil was 0.89%.

[0112] Example 5

[0113] At 20 ° C and 500 rpm, 0.8 g of branched tail chain anionic sodium sulfonate surfactant BC 16 SO3Na and 0.3g of α-cyclodextrin were added to 98.9g of water and stirred for 25min until completely dissolved to obtain a cleaning oil composition.

[0114] Methods for remediating heavy oil contaminated soil:

[0115] (1) Weigh 10 g of oil-containing soil, add 80 g of high-efficiency oil washing system into a conical flask, place it in a shaker, heat it to 65°C, and shake it at a constant speed for 3 hours.

[0116] (2) The mixture of the oil-containing soil and the oil-washing composition was allowed to stand and settle, and the upper solution was removed and transferred to a graduated centrifuge tube. The mixture was centrifuged at 6000 rpm, and the volume of the separated oil (V) was read as 0.44 mL. The lower solid was dried and weighed.

[0117] The oil washing efficiency of Example 5 was calculated to be 81.14% by the formula, and the residual oil content in the soil was 0.99%.

[0118] Comparative Example 1

[0119] At 35° C. and 500 rpm, 1 g of linear anionic sodium sulfonate surfactant AOS and 0.5 g of β-cyclodextrin were added to 98.5 g of water and stirred for 15 minutes until completely dissolved to obtain a cleaning oil composition.

[0120] Methods for remediating heavy oil contaminated soil:

[0121] (1) Weigh 10 g of oil-containing soil, add 60 g of the oil-washing composition into a conical flask, place it in a shaker, heat it to 60°C, and shake it at a constant speed for 4 hours.

[0122] (2) The mixture of the oil-containing soil and the oil-washing composition was allowed to stand and settle, and the upper solution was removed and transferred to a graduated centrifuge tube. The mixture was centrifuged at 6000 rpm, and the volume of the separated oil (V) was read as 0.32 mL. The lower solid was dried and weighed.

[0123] The oil washing efficiency of Comparative Example 1 was obtained by calculation formula to be 59.0%, and the residual oil content in the soil was 2.13%.

[0124] Comparative Example 2

[0125] 1.5 g of β-cyclodextrin was added to 98.5 g of water at 35° C. and 500 rpm, and stirred for 15 minutes until completely dissolved to obtain a cleaning oil composition.

[0126] Methods for remediating heavy oil contaminated soil:

[0127] (1) Weigh 10 g of oil-containing soil, add 60 g of the oil-washing composition into a conical flask, place it in a shaker, heat it to 60°C, and shake it at a constant speed for 4 hours.

[0128] (2) The mixture of the oil-containing soil and the oil-washing composition was allowed to stand and settle, and the upper solution was taken out and transferred to a graduated centrifuge tube. The mixture was centrifuged at 6000 rpm, and the volume of the separated oil (V) was read as 0.24 mL. The lower solid was dried and weighed.

[0129] The oil washing efficiency of Comparative Example 2 was obtained by calculation formula to be 44.3%, and the residual oil content in the soil was 2.88%.

[0130] Comparative Example 3

[0131] At 35°C and 500 rpm, 1.5 g of branched tail chain anionic sodium sulfonate surfactant BC 16 SO3Na was added to 98.5 g of water and stirred for 15 min until completely dissolved to obtain a washing oil composition.

[0132] Methods for remediating heavy oil contaminated soil:

[0133] (1) Weigh 10 g of oil-containing soil, add 60 g of the oil-washing composition into a conical flask, place it in a shaker, heat it to 60°C, and shake it at a constant speed for 4 hours.

[0134] (2) The mixture of the oil-containing soil and the oil-washing composition was allowed to stand and settle, and the upper solution was removed and transferred to a graduated centrifuge tube. The mixture was centrifuged at 6000 rpm, and the volume of the separated oil (V) was read as 0.31 mL. The lower solid was dried and weighed.

[0135] The oil washing efficiency of Comparative Example 3 was obtained by calculation formula to be 57.2%, and the residual oil content in the soil was 2.21%.

[0136] The above five examples show that the oil washing compositions formed by compounding the branched tail-chain anionic sodium sulfonate surfactant and cyclodextrin have an oil washing efficiency of over 80%, and the residual oil content in the soil can be reduced to as low as 0.51%, showing a good elution effect on heavy oil pollutants.

[0137] In Example 1, compared with Comparative Example 1, a linear anionic sulfonate surfactant, AOS, was substituted for a branched tail anionic sulfonate surfactant. The surfactant was mixed with cyclodextrin and water to prepare a lotion composition. The experimental results showed that the branched tail anionic sodium sulfonate surfactant exhibited superior oil-cleaning performance compared to conventional linear anionic sulfonate surfactants. This is due to the branched tail structure, which imparts a stronger wetting reversal capability to the sodium sulfonate surfactant.

[0138] Comparison of Example 1 with Comparative Examples 2 and 3 reveals that while using either cyclodextrin or a branched tail anionic sodium sulfonate surfactant alone to prepare a detergent composition can effectively remove heavy oil contaminants, the oil removal efficiency is low. Therefore, both the branched tail anionic sodium sulfonate surfactant and cyclodextrin are essential in the detergent composition provided by the present invention.

[0139] At the same time, the branched tail chain anionic sodium sulfonate surfactant and cyclodextrin are non-toxic, easily biodegradable, and will not produce secondary pollution. Therefore, the method for repairing heavy oil-contaminated soil provided by the present invention is green and environmentally friendly.

[0140] In summary, the detergent composition provided by the present invention effectively cleans oil films on soil surfaces through the effective synergy between the curling and exfoliating effects of the branched tail-chain anionic sodium sulfonate surfactant and the solubilizing effect of cyclodextrin. Its oil removal efficiency reaches over 80%, and the residual oil content in the soil can be reduced to as low as 0.51%. It features low usage, high oil removal efficiency, and easy biodegradation. Furthermore, the oil removal composition provided by the present invention can be used in the remediation and treatment of heavy oil-contaminated soil in the petroleum and petrochemical industries, achieving efficient and green leaching of heavy oil contaminants.

[0141] The preferred embodiments of the present invention have been described in detail above, 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 disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. An oil washing composition for repairing heavy oil-contaminated soil, characterized in that: The cleaning oil composition contains the following components which are stored separately or in combination: anionic sulfonate surfactant, cyclodextrin and water; The anionic sulfonate surfactant is a branched tail chain anionic sulfonate surfactant having a structure shown in formula (I). Formula (I), In formula (I), M is Na, K, Li or NH4; Based on the total weight of the washing oil composition, the content of the anionic sulfonate surfactant is 0.5-1 wt %, the content of the cyclodextrin is 0.1-0.5 wt %, and the content of water is 98.5-99.4 wt %.

2. The cleaning oil composition according to claim 1, wherein In formula (I), M is Na, K or NH4.

3. The cleaning oil composition according to claim 2, wherein In formula (I), M is Na.

4. The cleaning oil composition according to claim 1, wherein The cyclodextrin is selected from α -cyclodextrin, β -cyclodextrin and γ - at least one of cyclodextrins.

5. The cleaning oil composition according to claim 4, wherein The cyclodextrin is β - cyclodextrin and / or γ -Cyclodextrin.

6. The washing oil composition according to any one of claims 1 to 5, wherein Based on the total weight of the washing oil composition, the content of the anionic sulfonate surfactant is 0.8-1 wt %, the content of the cyclodextrin is 0.3-0.5 wt %, and the content of water is 98.5-98.9 wt %.

7. A method for preparing the washing oil composition according to any one of claims 1 to 6, characterized in that: The method comprises: mixing an anionic sulfonate surfactant, cyclodextrin and water; Wherein, the definition of the anionic sulfonate surfactant is the same as the definition of the anionic sulfonate surfactant described in any one of claims 1 to 3; Based on the total weight of the anionic sulfonate surfactant, the cyclodextrin and the water, the amount of the anionic sulfonate surfactant is 0.5-1wt%, the amount of the cyclodextrin is 0.1-0.5wt%, and the amount of the water is 98.5-99.4wt%.

8. The method according to claim 7, wherein: The cyclodextrin is selected from α -cyclodextrin, β -cyclodextrin and γ - at least one of cyclodextrins.

9. The method according to claim 8, wherein The cyclodextrin is β - cyclodextrin and / or γ -Cyclodextrin.

10. The method according to any one of claims 7 to 9, wherein: Based on the total weight of the anionic sulfonate surfactant, the cyclodextrin and the water, the amount of the anionic sulfonate surfactant is 0.8-1wt%, the amount of the cyclodextrin is 0.3-0.5wt%, and the amount of the water is 98.5-98.9wt%.

11. The method according to any one of claims 7 to 9, wherein: The mixing conditions at least meet the following requirements: temperature of 15-40° C., stirring speed of 300-800 rpm, and stirring time of 10-30 min.

12. Use of the oil washing composition according to any one of claims 1 to 6 in remediating soil contaminated by heavy oil.

13. A method for remediating heavy oil-contaminated soil, characterized in that: The method includes: (1) contacting and eluting the oil washing composition according to any one of claims 1 to 6 with heavy oil-contaminated soil to obtain a mixture I; (2) subjecting the mixture I to solid-liquid separation.

14. The method according to claim 13, wherein In step (1), the contact elution conditions at least meet the following requirements: temperature of 25-80°C and time of 1-6 hours.

15. The method according to claim 14, wherein In step (1), the contact elution conditions at least meet the following requirements: temperature of 40-60°C and time of 2-4 hours.

16. The method according to claim 13, wherein: The weight ratio of the oil washing composition to the heavy oil contaminated soil is 3:1 to 10:

1.

17. The method according to claim 16, wherein The weight ratio of the oil washing composition to the heavy oil contaminated soil is 3:1 to 6:

1.

18. The method according to any one of claims 13 to 17, wherein: The hydrocarbon oil content in the heavy oil-contaminated soil is greater than or equal to 5 wt %.

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