Raw material composition of surface active agent, surface active agent, preparation method of surface active agent and application of surface active agent in soil remediation

Abstract

The invention discloses a raw material composition of a surfactant, the surfactant, a preparation method of the surfactant and application of the surfactant in soil remediation. The raw material composition of the surfactant comprises the following raw materials: a monomer, an initiator and a chain transfer agent, the monomers comprise an acrylamide monomer, a maleic anhydride monomer and a sodium p-styrenesulfonate monomer. The preparation method comprises the following steps: in a protective atmosphere, carrying out polymerization reaction on the raw material composition in water, and adjusting the pH value to obtain the surfactant. The multifunctional polymer surfactant disclosed by the invention can still effectively improve the solubility of petroleum hydrocarbon in water under the conditions of high salt ion concentration and high temperature, so that the petroleum hydrocarbon adsorbed on the surfaces of soil particles is promoted to be desorbed and further removed; therefore, the purpose of repairing the polluted soil of the saline-alkali land or strengthening the repairing effect by being combined with other repairing technologies is achieved.

Description

Technical Field

[0001] This invention relates to the technical field of soil remediation, and more specifically, to raw material compositions of surfactants, surfactants and their preparation methods, and their applications in soil remediation. Background Technology

[0002] Globally, oil is the most consumed fossil fuel compared to other energy sources such as coal and natural gas. During oil extraction, pipeline transportation, storage, and processing, increasing amounts of petroleum hydrocarbon pollutants are released into the soil. The presence of these pollutants not only damages the soil environment but also poses threats to human health and ecosystems.

[0003] In the development of soil remediation technologies, surfactants can quickly treat highly contaminated soil with relatively low costs and can be coupled with other methods to improve effectiveness and shorten treatment cycles. However, in some remediation scenarios, the susceptibility of surfactants to salt ions in the soil or their tendency to degrade under high temperatures limits their application and makes it difficult to achieve the desired results.

[0004] Polymer surfactants possess a range of unique properties due to their abundance of hydrophilic and hydrophobic groups, the adjustable size and position of which give rise to excellent dispersion, emulsification, resistance to salt ion interference, and stability under high-temperature conditions. These properties make them a class of surfactants with great practical value and promising future prospects.

[0005] Currently, most of the polymer surfactants disclosed in the literature are used in fields such as oil displacement, and there are no reports on surfactants that are suitable for the field of contaminated soil remediation technology and have salt and high temperature resistance.

[0006] Therefore, developing a salt- and high-temperature resistant polymer surfactant can provide important technical support for the remediation of contaminated soils such as saline-alkali land and for enhancing the effect of thermal desorption remediation. Summary of the Invention

[0007] To address the problems in existing technologies, this invention proposes a raw material composition for surfactants, the surfactant itself, its preparation method, and its application in soil remediation, along with its preparation method and application. The multifunctional polymer surfactant of this invention can effectively increase the solubility of petroleum hydrocarbons in water even under high salt ion concentrations and high temperatures, promoting the desorption and removal of petroleum hydrocarbons adsorbed on the surface of soil particles. This achieves the purpose of remediating saline-alkali contaminated soil or enhancing the remediation effect when combined with other remediation technologies.

[0008] One object of the present invention is to provide a raw material composition for preparing a surfactant, comprising the following raw materials:

[0009] Monomers, initiators, and chain transfer agents; the monomers include acrylamide monomers, maleic anhydride monomers, and sodium styrene sulfonate monomers.

[0010] In the raw material composition for preparing surfactants according to the present invention, preferably,

[0011] In the monomer, the molar ratio of sodium styrene sulfonate to maleic anhydride is (40-55):(30-55), preferably (40-50):(40-50); and / or,

[0012] For example, in the monomers described in this invention, the molar ratio of sodium styrene sulfonate to maleic anhydride is (40, 42, 44, 45, 46, 48, 50, 52, 54, 55): (30, 32, 34, 35, 36, 38, 40, 42, 44, 45, 46, 48, 50, 52, 54, 55);

[0013] In the monomer, the molar ratio of sodium styrene sulfonate to acrylamide is (40-55):(10-30); preferably, the molar ratio of sodium styrene sulfonate to acrylamide is (40-50):(25-30).

[0014] For example, in the monomers described in this invention, the molar ratio of sodium styrene sulfonate to acrylamide is (40, 42, 44, 45, 46, 48, 50, 52, 54, 55): (10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, 30).

[0015] In the raw material composition for preparing surfactants according to the present invention, preferably,

[0016] The initiator is selected from at least one of peroxides or azo compounds; and / or,

[0017] The amount of the initiator is 0.1% to 10% of the total mass of the monomer; for example, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 5%, 6%, 7%, 8%, 9%, 10%.

[0018] Preferably,

[0019] The peroxide is selected from at least one of sodium persulfate or ammonium persulfate; and / or,

[0020] The azo compound is selected from azobisisobutyronitrile; and / or,

[0021] The amount of the initiator is 0.5% to 4% of the total mass of the monomer.

[0022] In the raw material composition for preparing surfactants according to the present invention, preferably,

[0023] The chain transfer agent is selected from at least one of isopropanol, sodium bisulfite, or a thiol compound; and / or,

[0024] The chain transfer agent is used in an amount of 4% to 15% of the total mass of the monomer; for example, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%.

[0025] Preferably,

[0026] The thiol compound is selected from at least one of mercaptoethanol, mercaptoacetic acid, or mercaptopropanol; and / or,

[0027] The chain transfer agent is used in an amount of 5% to 10% of the total mass of the monomer.

[0028] A second objective of this invention is to provide a surfactant prepared from a raw material composition comprising one of the objectives of this invention.

[0029] In the surfactants described in this invention, preferably,

[0030] The surfactant has the following general structural formula:

[0031]

[0032] In terms of molar ratio, y:x is (40-55):(30-55); y:z is (40-55):(10-30); for example, y:x is (40, 42, 44, 45, 46, 48, 50, 52, 54, 55):(30, 32, 34, 35, 36, 38, 40, 42, 44, 45, 46, 48, 50, 52, 54, 55), and y:z is (40, 42, 44, 45, 46, 48, 50, 52, 54, 55):(10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, 30).

[0033] Preferably, in terms of molar ratio, y:x is (40-50):(40-50); y:z is (40-50):(25-30).

[0034] In the surfactants described in this invention, preferably,

[0035] The surfactant has a weight-average molecular weight of 5,000 to 20,000; preferably 8,000 to 16,000; and more preferably 10,000 to 16,000.

[0036] A third objective of this invention is to provide a method for preparing a surfactant, comprising the following steps:

[0037] Under a protective atmosphere, the raw material composition comprising one of the objectives of this invention is polymerized in water, and the pH is adjusted to obtain the surfactant;

[0038] Preferably, it is used for the preparation of the surfactant described in the second objective of the present invention.

[0039] In the method for preparing the surfactant described in this invention, preferably,

[0040] The monomer is dissolved in water, and an initiator and a chain transfer agent are added dropwise under a protective atmosphere, heating, and stirring to carry out a polymerization reaction, resulting in an aqueous solution containing the surfactant. The pH is adjusted and the solution is dried to obtain the surfactant.

[0041] More preferably, acrylamide and maleic anhydride are added to a three-necked flask, deionized water is added and stirred to dissolve, sodium styrene sulfonate is added and stirred to dissolve, then a protective gas is introduced to replace the air in the solution, the three-necked flask is then placed in a constant temperature water bath for heating, an initiator and a chain transfer agent are added dropwise, the reaction is stirred at a constant temperature to obtain an aqueous solution of surfactant, the pH is adjusted to neutral, and after constant temperature drying, it is pulverized into a solid powder to obtain a polymer surfactant;

[0042] In the method for preparing the surfactant described in this invention, preferably,

[0043] The amount of water used is 3 to 9 times the total mass of the monomers; preferably 3 to 6 times; for example, 3, 5, 6, 8, or 9 times; and / or,

[0044] The polymerization reaction is carried out at a temperature of 50–80°C; preferably 65–80°C; for example, 50, 55, 60, 65, 70, 75, or 80°C; and / or,

[0045] The polymerization reaction takes 20–100 min; preferably 60–100 min; for example, 20, 40, 40, 60, 80, or 100 min; and / or,

[0046] The stirring rate is 50–1000 r / min; preferably 150–400 r / min; for example, 50, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 r / min; and / or,

[0047] Adjust the pH to 5-8; preferably adjust the pH to neutral.

[0048] In the technical solution of this invention, the pH of the aqueous solution of the surfactant may cause hydrolysis of amide groups and twisting of polymer molecular chains, affecting polymer performance. Therefore, it is necessary to adjust the pH to a suitable range.

[0049] In the technical solution of this invention, pH can be adjusted using existing pH-adjusting substances, such as sodium hydroxide solution.

[0050] The fourth objective of this invention is to provide an application of a surfactant as described in the second objective of this invention or a surfactant prepared by the method described in the third objective of this invention in soil remediation; preferably, its application in the remediation of petroleum hydrocarbon-contaminated soil.

[0051] In the application described in this invention, preferably,

[0052] The soil remediation process includes the step of injecting the surfactant into the soil. Preferably, during injection, the ambient temperature of the soil is 100-170°C and the total salt content of the soil is 0.2wt%-3wt%.

[0053] The present invention also provides the application of the above-mentioned multifunctional polymer surfactant in soil remediation (including saline-alkali land); for example, the surfactant can be used for ex-situ elution of petroleum hydrocarbon contaminated soil, and can also be used for in-situ soil remediation. By injecting the surfactant, the pollutants are solubilized, thereby enhancing the processes of multiphase extraction, thermal desorption, chemical oxidation and microbial remediation, improving remediation efficiency and shortening remediation time.

[0054] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In the following, various technical solutions can, in principle, be combined with each other to obtain new technical solutions, which should also be considered as specifically disclosed herein.

[0055] The multifunctional polymer surfactant for remediation of petroleum hydrocarbon-contaminated soil provided by this invention has the following advantages:

[0056] The synthesis of existing surfactants generally requires organic solvents, while the monomers of the surfactants prepared by this invention are all water-soluble, and deionized water can be used as a solvent during their polymerization, avoiding the generation of a large amount of organic waste liquid and minimizing environmental pollution.

[0057] The polymer surfactant synthesized in this invention encapsulates contaminants through long molecular chains, with hydrophobic groups facing inward and hydrophilic groups facing outward, thereby achieving the purpose of solubilizing contaminants. Furthermore, the chain length of the polymer needs to be controlled by adding a chain transfer agent, because excessively long molecular chains may cause the polymer to curl and fail to exhibit solubilizing properties.

[0058] The polymer surfactant prepared by the method of this invention uses a carbon-carbon backbone structure and introduces hydrophilic groups such as sulfonic acid groups and carboxyl groups. This results in a polymer surfactant that not only possesses good solubilizing ability for petroleum hydrocarbons but also exhibits excellent thermal stability and resistance to salt ion interference. The surfactant of this invention still exhibits good solubilizing effects at a temperature of 170℃ and a salt content of 3%, making it applicable to the remediation of saline-alkali contaminated soil. It can also be used in combination with multiphase extraction, thermal desorption, chemical oxidation, and microbial remediation techniques to improve remediation efficacy and shorten remediation time. Attached Figure Description

[0059] Figure 1 This is a schematic diagram of the polymerization reaction experimental setup;

[0060] Figure 2 Schematic diagram of the experimental setup for evaluating the high-temperature resistance of surfactants;

[0061] Figure 3 The infrared spectrum of the polymer surfactant prepared in Example 1 of this invention is shown.

[0062] Explanation of reference numerals in the attached figures:

[0063] 1-Constant temperature water bath; 2-Three-necked flask; 3-Condenser; 4-Protective gas inlet; 5-Magnetic rotor; 6-Steam generator; 7-Soil column; 8-Heat exchanger; 9-Gas-liquid separator; 10-Activated carbon adsorption tank. Detailed Implementation

[0064] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0065] It should also be noted that the various specific technical features described in the following embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the various possible combinations will not be described separately in this invention.

[0066] Furthermore, various embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention. The resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0067] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, such as those that can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0068] Example 1

[0069] like Figure 1 The experimental setup shown involves adding 21g of acrylamide and 29g of maleic anhydride to a three-necked flask 2, followed by 532g of deionized water. The mixture is then dissolved by stirring with a magnetic rotor 5. Next, 82g of sodium styrene sulfonate is added and stirred until homogeneous. Nitrogen gas is then introduced through a protective gas inlet 4 for 10 minutes to replace any air in the solution. The three-necked flask is then heated in a 70°C constant-temperature water bath 1, with a condenser 3 attached to the flask. 1.3g of azobisisobutyronitrile and 9.3g of mercaptopropanol are added dropwise to the three-necked flask. The mixture is stirred at a constant temperature for 30 minutes at a stirring rate of 200 rpm until the polymerization reaction is complete, yielding an aqueous solution of the surfactant. A 20% sodium hydroxide aqueous solution is added dropwise to adjust the pH to neutral. After drying at a constant temperature, the solution is pulverized into a solid powder to obtain the polymer surfactant.

[0070] The structural formula of the polymer surfactant prepared in the above manner is as follows:

[0071]

[0072] In terms of molar ratio, y:x is 40:30; y:z is 40:30.

[0073] The polymer surfactant prepared in Example 1 was subjected to infrared spectroscopy detection, and the results are as follows: Figure 3 As shown in the figure. 3435cm -1 A stretching vibration peak of carboxyl hydroxyl group appears at 1396 cm⁻¹. -1 An absorption peak for the stretching vibration of NH appears; 1653 cm⁻¹ -1 The characteristic absorption peak of the carbonyl group appears at 1561 cm⁻¹. -1 An absorption peak for the stretching vibration of the benzene ring skeleton appears at 1125 cm⁻¹. -1 The characteristic absorption peak of the sulfonic acid group appears at 704 cm⁻¹. -1 The peak at this location is a characteristic peak of monosubstituted benzene rings. The analytical results indicate that all three monomers participated in the polymerization reaction, and are essentially consistent with the target product.

[0074] The weight-average molecular weight of the polymer surfactant prepared above is 12,500.

[0075] Evaluation method:

[0076] Soil contaminated with petroleum hydrocarbons (C10–C40) was prepared with a concentration of 8200 mg / kg. The prepared polymer surfactant was then subjected to performance evaluation experiments as follows.

[0077] 1) Evaluation of high temperature resistance

[0078] Mix 7.5g of polymer surfactant with 50mL of deionized water, then mix thoroughly with 500g of contaminated soil and pack into soil column 7. The steam generated by steam generator 6 is at a temperature of 100, 140, or 170℃. Steam is injected into soil column 7 through a pipe. After the pollutants are desorbed from the soil with the steam, they pass through condenser 8, then into gas-liquid separator 9. The exhaust gas is recovered through activated carbon adsorption tank 10. Steam injection continues for 40 minutes. The specific testing apparatus is as follows: Figure 2 As shown, this test uses an existing testing setup.

[0079] In the comparative experiment, no surfactant was added to the contaminated soil, and all other conditions were the same.

[0080] After the experiment, the concentration of petroleum hydrocarbons in the soil was measured, and the petroleum hydrocarbon removal rate was calculated. The results are shown in Table 1.

[0081] 2) Evaluation of salt resistance

[0082] Preparation of saline-contaminated soil: Sodium chloride, calcium chloride, and magnesium sulfate were added to the prepared contaminated soil and mixed thoroughly to control the total salt content of the soil to approximately 0.2 wt%, 1 wt%, or 3 wt%. A 1 wt% aqueous solution of the polymer surfactant was prepared. At a water-to-soil ratio of 4:1, 50 g of contaminated soil and 200 mL of surfactant solution were placed in a 500 mL Erlenmeyer flask, shaken well, and sealed. The flask was shaken every 8 hours to ensure thorough mixing of the soil and solution. After 24 hours, the lower soil layer was separated using a centrifuge, and the concentration of petroleum hydrocarbons was measured to calculate the petroleum hydrocarbon removal rate. The results are shown in Table 2.

[0083] Example 2

[0084] 21g of acrylamide and 39g of maleic anhydride were added to a three-necked flask, followed by 490g of deionized water and stirring to dissolve. Then, 103g of sodium styrene sulfonate was added and stirred until homogeneous. Nitrogen gas was then introduced for 10 minutes to replace the air in the solution. The three-necked flask was then heated in a constant temperature water bath at 75°C. 3.3g of azobisisobutyronitrile and 14.7g of mercaptoacetic acid were added dropwise. The mixture was stirred at a constant temperature for 60 minutes at a stirring rate of 100r / min until the polymerization reaction was complete, yielding an aqueous solution of the surfactant. A 20% sodium hydroxide aqueous solution was added dropwise to adjust the pH to neutral. After drying at a constant temperature, the solution was pulverized into a solid powder to obtain the polymer surfactant.

[0085] The structural formula of the polymer surfactant prepared in the above manner is as follows:

[0086]

[0087] In terms of molar ratio, y:x is 50:40; y:z is 50:30.

[0088] The weight-average molecular weight of the polymer surfactant prepared above is 10200.

[0089] The high-temperature resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 1.

[0090] The salt resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 2.

[0091] Example 3

[0092] 14g of acrylamide and 44g of maleic anhydride were added to a three-necked flask, followed by 1029g of deionized water and stirring to dissolve. Then, 113g of sodium styrene sulfonate was added and stirred until homogeneous. Nitrogen gas was then introduced for 15 minutes to replace the air in the solution. The three-necked flask was then placed in a constant temperature water bath at 65°C and heated. 3.4g of ammonium persulfate and 17g of mercaptoethanol were added dropwise. The mixture was stirred at a constant temperature for 35 minutes at a stirring rate of 600r / min until the polymerization reaction was complete, resulting in an aqueous solution of the surfactant. A 20% sodium hydroxide aqueous solution was added dropwise to adjust the pH to neutral. After drying at a constant temperature, the solution was pulverized into a solid powder to obtain the polymer surfactant.

[0093] The structural formula of the polymer surfactant prepared in the above manner is as follows:

[0094]

[0095] In terms of molar ratio, y:x is 55:45; y:z is 55:20.

[0096] The weight-average molecular weight of the polymer surfactant prepared above is 8600.

[0097] The high-temperature resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 1.

[0098] The salt resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 2.

[0099] Example 4

[0100] 17g of acrylamide and 49g of maleic anhydride were added to a three-necked flask, followed by 672g of deionized water and stirring to dissolve. Then, 82g of sodium styrene sulfonate was added and stirred until homogeneous. Nitrogen gas was then introduced for 10 minutes to replace the air in the solution. The three-necked flask was then placed in a constant temperature water bath at 70°C and heated. 2.0g of sodium persulfate and 10g of mercaptoacetic acid were added dropwise. The mixture was stirred at a constant temperature for 60 minutes at a stirring rate of 400r / min until the polymerization reaction was complete, yielding an aqueous solution of the surfactant. A 20% sodium hydroxide aqueous solution was added dropwise to adjust the pH to neutral. After drying at a constant temperature, the solution was pulverized into a solid powder to obtain the polymer surfactant.

[0101] The structural formula of the polymer surfactant prepared in the above manner is as follows:

[0102]

[0103] In terms of molar ratio, y:x is 40:50; y:z is 40:24.

[0104] The weight-average molecular weight of the polymer surfactant prepared above is 12,000.

[0105] The high-temperature resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 1.

[0106] The salt resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 2.

[0107] Example 5

[0108] 21g of acrylamide and 49g of maleic anhydride were added to a three-necked flask, followed by 519g of deionized water and stirring to dissolve. Then, 103g of sodium styrene sulfonate was added and stirred until homogeneous. Nitrogen gas was then purged into the solution for 10 minutes to replace the air. The three-necked flask was then heated in a constant-temperature water bath at 60°C. 6.9g of sodium persulfate and 8.6g of isopropanol were added dropwise. The mixture was stirred at a constant temperature for 30 minutes at a stirring rate of 800r / min until the polymerization reaction was complete, yielding an aqueous solution of the surfactant. A 20% sodium hydroxide aqueous solution was added dropwise to adjust the pH to neutral. After drying at a constant temperature, the solution was pulverized into a solid powder to obtain the polymer surfactant.

[0109] The structural formula of the polymer surfactant prepared in the above manner is as follows:

[0110]

[0111] In terms of molar ratio, y:x is 50:50; y:z is 50:30.

[0112] The weight-average molecular weight of the polymer surfactant prepared above is 16,000.

[0113] The high-temperature resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 1.

[0114] The salt resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 2.

[0115] Comparative Example 1

[0116] It uses the same proportions and preparation method as Example 5, the only difference being that maleic anhydride is replaced with an equimolar amount of acrylamide.

[0117] The high-temperature resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 1.

[0118] The salt resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 2.

[0119] Comparative Example 2

[0120] It uses the same proportions and preparation method as Example 5, the only difference being that acrylamide is replaced with an equimolar amount of maleic anhydride.

[0121] The high-temperature resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 1.

[0122] The salt resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 2.

[0123] Comparative Example 3

[0124] It adopts the same preparation method as Example 1, except that the molar ratio of sodium styrene sulfonate to maleic anhydride in the monomer is 20:20; and the molar ratio of sodium styrene sulfonate to acrylamide is 20:40.

[0125] The high-temperature resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 1.

[0126] The salt resistance performance was evaluated using the same evaluation method as in Example 1, and the results are shown in Table 2.

[0127] The ratios of x, y, and z in the polymer surfactants prepared in the above embodiments of the present invention were calculated based on the amount of raw materials fed.

[0128] The results of evaluating the high-temperature and salt resistance properties of the polymer surfactants prepared in Examples 1-5 and Comparative Examples 1-3 are as follows:

[0129] Table 1 Evaluation of High Temperature Resistance

[0130]

[0131] Table 2 Evaluation of Salt Resistance

[0132]

[0133] As can be seen from Tables 1 and 2, the multifunctional surfactants prepared in Examples 1-5 of this application still exhibit good solubilizing effects at temperatures ranging from 100 to 170°C and in soil contents ranging from 0.2% to 3%. Among these, Example 4 demonstrates the best resistance to high temperatures and salt ion interference compared to the other examples.

[0134] By comparing the results of Example 5, Comparative Example 1 and Comparative Example 2, it can be seen that in the surfactant of the present invention, acrylamide and maleic anhydride have a synergistic effect when copolymerized with sodium styrene sulfonate. The surfactant prepared by this method has a better solubilizing effect on pollutants such as petroleum hydrocarbons and better resistance to high temperature and salt ion interference.

[0135] A comparison of the results of Example 1 and Comparative Example 3 shows that the surfactant in Comparative Example 3, which is outside the formulation range of this invention, has poor solubilizing effect and poor resistance to high temperature and salt ion interference. In this invention, sodium styrene sulfonate provides not only sulfonic acid groups but also benzene rings to enhance the polymer's temperature resistance. Maleic anhydride hydrolysis provides carboxylate groups to increase the polymer's hydrophilicity, and amide groups can also enhance the polymer's stability and water solubility. However, practice shows that too many amide groups are not advisable, as they significantly affect the performance of the polymer surfactant.

[0136] In summary, the multifunctional polymer surfactant of this invention can effectively improve the solubility of petroleum hydrocarbons in water even under high salt ion concentrations and high temperatures, promoting the desorption and removal of petroleum hydrocarbons adsorbed on the surface of soil particles. The multifunctional polymer surfactant provided by this invention can be applied to the remediation of saline-alkali contaminated soil or used in combination with other remediation technologies to enhance remediation effects and shorten remediation time.

[0137] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0138] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0139] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application’s filing, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0140] In the context of this specification, except where expressly stated otherwise, any matters or issues not mentioned shall apply directly to those known in the art without any modification.

Claims

1. A raw material composition for a surfactant, characterized in that, Including the following raw materials: Monomers, initiators, and chain transfer agents; the monomers include acrylamide monomers, maleic anhydride monomers, and sodium styrene sulfonate monomers.

2. The surfactant raw material composition according to claim 1, characterized in that: In the monomer, the molar ratio of sodium styrene sulfonate to maleic anhydride is (40-55):(30-55), preferably (40-50):(40-50); and / or, In the monomer, the molar ratio of sodium styrene sulfonate to acrylamide is (40-55):(10-30); preferably, the molar ratio of sodium styrene sulfonate to acrylamide is (40-50):(25-30).

3. The surfactant raw material composition according to claim 1, characterized in that: The initiator is selected from at least one of peroxides or azo compounds; and / or, The amount of the initiator is 0.1% to 10% of the total mass of the monomer; Preferably, The peroxide is selected from at least one of sodium persulfate or ammonium persulfate; and / or, The azo compound is selected from azobisisobutyronitrile; and / or, The amount of the initiator is 0.5% to 4% of the total mass of the monomer.

4. The raw material composition of the surfactant according to claim 1, characterized in that: The chain transfer agent is selected from at least one of isopropanol, sodium bisulfite, or a thiol compound; and / or, The chain transfer agent is used in an amount of 4% to 15% of the total mass of the monomer; Preferably, The thiol compound is selected from at least one of mercaptoethanol, mercaptoacetic acid, or mercaptopropanol; and / or, The chain transfer agent is used in an amount of 5% to 10% of the total mass of the monomer.

5. A surfactant, characterized in that: The surfactant is prepared from the raw material composition comprising any one of claims 1-4.

6. The surfactant according to claim 5, characterized in that: The surfactant has the following general structural formula: In terms of molar ratio, y:x is (40-55):(30-55); y:z is (40-55):(10-30); Preferably, in terms of molar ratio, y:x is (40-50):(40-50); y:z is (40-50):(25-30).

7. The surfactant according to claim 5, characterized in that: The surfactant has a weight-average molecular weight of 5,000 to 20,000; preferably 8,000 to 16,000; and more preferably 10,000 to 16,000.

8. A method for preparing a surfactant, characterized in that, Includes the following steps: Under a protective atmosphere, the raw material composition comprising any one of claims 1-4 is polymerized in water, and the pH is adjusted to obtain the surfactant; It is preferably used in the preparation of the surfactant according to any one of claims 5-7.

9. The method for preparing the surfactant according to claim 8, characterized in that: The monomer was dissolved in water, and an initiator and a chain transfer agent were added dropwise under a protective atmosphere, heating, and stirring to carry out a polymerization reaction. The pH was adjusted, and the mixture was dried to obtain the surfactant.

10. The method for preparing the surfactant according to claim 9, characterized in that: The amount of water used is 3 to 9 times the total mass of the monomers; preferably 3 to 6 times; and / or, The polymerization reaction is carried out at a temperature of 50–80°C; preferably 65–80°C; and / or, The polymerization reaction takes 20–100 min; preferably 60–100 min; and / or, The stirring rate is 50–1000 r / min; preferably 150–400 r / min; and / or, Adjust the pH to 5-8; preferably adjust the pH to neutral.

11. The application of a surfactant as described in any one of claims 5-7 or a surfactant prepared by the method described in any one of claims 8-10 in soil remediation; preferably in the remediation of petroleum hydrocarbon contaminated soil.

12. The application according to claim 11, characterized in that: The soil remediation process includes the step of injecting the surfactant into the soil. Preferably, during injection, the ambient temperature of the soil is 100-170°C and the total salt content of the soil is 0.2wt%-3wt%.

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