Contaminated soil treatment agent, method for producing the same, and method for treating contaminated soil

Abstract

The present application discloses a contaminated soil treatment agent, a preparation method thereof and a contaminated soil treatment method. The contaminated soil treatment agent comprises the following components in parts by weight: (1) 1 part of fatty acid ester alkyl sulfonate; (2) 0.1-50 parts of hydrocarbyl amine polyether anionic surfactant; and (3) optionally 0.2-10 parts of nanoparticles. The contaminated soil treatment agent can form good foam, has good removal effect on heavy metal ions and organic pollutants in soil, is green and easy to degrade, and cannot cause secondary pollution.

Description

Technical Field

[0001] This invention relates to the technical field of soil remediation, and more specifically, to contaminated soil treatment agents, their preparation methods, and methods for treating contaminated soil. Background Technology

[0002] Soil pollution caused by pollutants from chemical plants such as pesticide, dye, petrochemical, and paper mills is mainly caused by organic residues.

[0003] Furthermore, the world has entered an era of information and intelligence, with electronic products and devices being constantly innovated and upgraded, resulting in the disposal of increasingly more old electronic products and devices, thus creating a massive amount of e-waste. E-waste contains various heavy metals, such as cadmium, chromium, lead, copper, mercury, zinc, and nickel. These factors contribute to the complexity of pollutants in the soil, making remediation more difficult than remediation of a single type of pollution.

[0004] Soil remediation technologies can be categorized into in-situ remediation and ex-situ remediation technologies based on the remediation location. In-situ remediation is more economical, while ex-situ remediation carries lower environmental risk and offers more controllable treatment effects, but has a smaller treatment range. In-situ chemical leaching is a highly efficient and thorough chemical remediation technology that removes soil pollutants. It primarily utilizes the adsorption and complexation between surfactants / complexing agents and heavy metals. By enhancing dissolution, adsorption, and elution, heavy metals in the soil are transferred to the liquid phase. Furthermore, the solubilizing effect of surfactants can encapsulate organic pollutants within the emulsion, thus simultaneously removing heavy metal ions and organic pollutants from the soil, thereby achieving the goal of remediating contaminated soil.

[0005] Patent CN112159666A describes a composite biological cleaning agent for nickel-contaminated soil. The eluent is prepared using saponin, Tween 80, and citric acid. It can simultaneously remove polychlorinated biphenyls and heavy metal pollution from the soil with a removal rate of over 80%. However, it employs an out-of-situ oscillation method.

[0006] Therefore, a more efficient treatment agent is needed to solve the problem of organic pollutants and heavy metal ions being trapped in the pores of heterogeneous soils, making removal difficult and causing secondary pollution during the treatment process. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention proposes a soil treatment agent, its preparation method, and a method for treating contaminated soil. The treatment agent of this invention, which removes organic pollutants and heavy metal ions from soil, can form good foam, exhibits excellent removal effects on heavy metal ions and organic pollutants in soil, and is green, easily degradable, and will not cause secondary pollution.

[0008] One objective of this invention is to provide a treatment agent for contaminated soil, comprising, by weight, the following substances:

[0009] (1) 1 part fatty acid ester alkoxysulfonate

[0010] (2) 0.1 to 50 parts of hydrocarbon amine polyether anionic surfactant; for example, 0.1, 0.2, 1, 2, 6, 8, 10, 15, 20, 25, 30, 35, 40, 45, 50 parts, or any range of any two of the above numbers;

[0011] (3) Selectively 0.2 to 10 parts of nanoparticles; for example, 0.2, 1, 2, 6, 8, 10 parts, or any range of any two of the above numbers.

[0012] In the treatment agent described in this invention, preferably,

[0013] The hydrocarbon-based amine polyether anionic surfactant has the general molecular formula shown in formula (II):

[0014]

[0015] In formula (II), R2 is selected from carbon atoms with the number of carbon atoms C8 to C9. 20 saturated or unsaturated hydrocarbon groups;

[0016] m, n, p, q may be the same or different, and each number is independently any number from 0 to 20, and m+n≥1; for example, m, n, p, q may be the same or different, and each number is independently 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or any range formed by any two of the above numbers;

[0017] X is an anionic group, and the two X's can be the same or different; M is a cation or cationic group that makes the general formula of the molecule electrically neutral, and the two M's can be the same or different.

[0018] Preferably, X is a monovalent anionic group.

[0019] Preferably,

[0020] In formula (II), R2 is selected from carbon atoms of C. 12 ~C 20 Saturated or unsaturated hydrocarbon groups; preferably straight-chain C 12 ~C 20 Saturated or unsaturated hydrocarbon groups; and / or,

[0021] m, n, p, q may be the same or different, each being an independent number from 0 to 5, and m+n≥1;

[0022] Preferably,

[0023] m+p is any number from 1 to 5; and / or,

[0024] n+q is any number from 0 to 5; and / or,

[0025] In this invention, the m+p in the preferred hydrocarbon amine polyether anionic surfactant is limited to any number from 1 to 5; and the n+q is limited to any number from 0 to 5. This is because, on the one hand, the ratio of ethoxy and propoxy groups needs to be appropriate to consider the HLB value; on the other hand, the limiting area occupied by the molecule cannot be too large. A suitable number of ethoxy and propoxy groups makes the performance of the hydrocarbon amine polyether anionic surfactant better.

[0026] X is selected from at least one of carboxylate and phosphate groups; and / or,

[0027] M is selected from alkali metal ions, NH4+ + At least one of them.

[0028] Preferably,

[0029] m, n, p, q may be the same or different, each being an independent number from 0 to 2, and m+n≥1; and / or,

[0030] The alkali metal ions are selected from Li + Na + K + 、Rb + At least one of them.

[0031] In this invention, the hydrocarbon-based amine polyether anionic surfactant, which is available in the prior art, can be purchased directly or synthesized according to existing methods, such as the preparation method comprising the following steps:

[0032] a. Under alkaline catalyst and protective atmosphere, R2NH2 reacts sequentially with the required amounts of propylene oxide and ethylene oxide to obtain compound (A);

[0033]

[0034] b. React the compound of formula (A) obtained in step a with an ionizing reagent and a base in a solvent to generate compound of formula (II).

[0035]

[0036] In step a, the alkaline catalyst is selected from alkali metal hydroxides, preferably at least one of sodium hydroxide and potassium hydroxide;

[0037] The molar ratio of ethylene oxide to R2NH2 is 0-40:1; the molar ratio of propylene oxide to R2NH2 is 0-40:1; and the ratio of the total molar amount of ethylene oxide and propylene oxide to the molar amount of R2NH2 is ≥1:1.

[0038] The reaction temperature in step a is 120–140 °C.

[0039] In step b, the base is selected from alkali metal hydroxides, preferably at least one of sodium hydroxide and potassium hydroxide;

[0040] The ionizing agent is XM-CH2-halogen; the halogen is selected from chlorine, bromine or iodine;

[0041] The solvent is selected from at least one of benzene-based solvents; preferably at least one of toluene and benzene; more preferably toluene / benzene (v / v = 1);

[0042] The molar ratio of compound (A), ionizing reagent, and base is 1:(2-20):(2-20);

[0043] The reaction temperature in step b is 50–120°C; the reaction time is 3–15 hours.

[0044] In the treatment agent described in this invention, preferably,

[0045] The fatty acid ester alkoxysulfonate has the general molecular formula shown in formula (I):

[0046]

[0047] In formula (I), R is selected from C 10 ~C 26 aliphatic hydrocarbon groups;

[0048] Preferably, the R is selected from linear C. 10 ~C 26 aliphatic hydrocarbon groups;

[0049] R' is selected from C1 to C4 hydrocarbon groups; preferably, R' is selected from C1 to C2 hydrocarbon groups.

[0050] -A is selected from -(C2H4O) a -(C3H6O) b - at least one of the following: where a is any number satisfying 0 < a ≤ 15, and b is any number satisfying 0 ≤ b ≤ 10; for example, a is any range consisting of 0.1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and any two of the above numbers; for example, b is any range consisting of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and any two of the above numbers.

[0051] Y + To make the general molecular formula an electrically neutral monovalent metal cation.

[0052] Preferably,

[0053] The fatty acid ester alkoxysulfonate has the general molecular formula shown in formula (III):

[0054]

[0055] Preferably,

[0056] The R is selected from C. 12 ~C 20 The aliphatic hydrocarbon group; preferably, the R is selected from straight-chain C. 12 ~C 20 aliphatic hydrocarbon groups; and / or,

[0057] The a is any integer from 1 to 10; and / or,

[0058] b is any integer from 0 to 8; and / or,

[0059] Y + Selected from Na + K + ;

[0060] Preferably,

[0061] a is any integer from 3 to 10; and / or,

[0062] b is any integer from 0 to 5;

[0063] More preferably,

[0064] b is 0; Y + Selected from Na + ;

[0065] More preferably,

[0066] The fatty acid ester alkoxysulfonate is sodium fatty acid methyl ester ethoxysulfonate.

[0067] The fatty acid ester alkoxysulfonate described in this invention is readily available in the prior art and can also be synthesized using existing methods, such as the following preparation methods:

[0068] a. Under the catalysis of a catalyst and the protection of nitrogen, α-olefin fatty acid methyl esters are heated and reacted with the required amounts of ethylene oxide and propylene oxide in sequence. After the reaction is completed, the temperature is lowered and the catalyst is filtered to obtain compound (B).

[0069]

[0070] b. Dissolve the compound of formula (B) in a solvent, then add the peroxide and heat for the first time; then add the aqueous solution of sodium bisulfite and sodium sulfite dropwise, heat for the reaction, cool after the reaction is completed, and then perform post-treatment to obtain the compound of formula (III).

[0071]

[0072] Preferably, in step a, the catalyst is selected from barium sulfate;

[0073] The amount of catalyst added is 0.8-1.2 wt% of the mass of the α-olefin fatty acid methyl ester, preferably 1 wt%.

[0074] The molar ratio of ethylene oxide to α-olefin fatty acid methyl ester is less than or equal to 15 and greater than 0.

[0075] The molar ratio of propylene oxide to α-olefin fatty acid methyl ester is 0-10;

[0076] The temperature for the heating reaction is 170-190 degrees Celsius; preferably 180 degrees Celsius.

[0077] In compound (B), R is selected from C. 10 ~C 26 aliphatic hydrocarbon groups;

[0078] In step b, the solvent is selected from isopropanol;

[0079] The molar volume ratio of compound (B) to solvent is 1 mole: 400-600 mL;

[0080] The peroxide is selected from tert-butyl peroxide; the molar volume ratio of compound (B) to peroxide is 1 mole: 4-6 mL;

[0081] The initial heating temperature is 40-50℃, preferably 45℃;

[0082] The second heating temperature is 70-80℃, and the reaction time is 2.5-4 hours, preferably 75℃ for 3 hours;

[0083] The molar ratio of sodium bisulfite to sodium sulfite is 1:0.2-0.4, preferably 1:0.3;

[0084] The molar ratio of compound (B) to sodium bisulfite and sodium sulfite is 1:1.2-1.4.

[0085] The post-treatment involved adjusting the pH of the system to 13 with a 25% sodium hydroxide aqueous solution and removing unreacted substances by chloroform extraction.

[0086] In the treatment agent described in this invention, preferably,

[0087] The nanoparticles are selected from at least one of silicon dioxide, calcium carbonate, and lithium saponite; preferably, the particle size of the nanoparticles is ≤80nm, more preferably 10-50nm.

[0088] In the treatment agent described in this invention, preferably,

[0089] The weight ratio of the fatty acid ester alkoxysulfonate to the hydrocarbon amine polyether anionic surfactant is 1:(0.2-10); and / or,

[0090] The weight ratio of the fatty acid ester alkoxysulfonate to the nanoparticles is 1:(0.2-5).

[0091] In the treatment agent described in this invention, preferably,

[0092] The treatment agent also includes a solvent.

[0093] In addition to fatty acid ester alkoxysulfonates, hydrocarbon amine polyether anionic surfactants, and optionally nanoparticles, the treatment agent of this invention may also include other substances commonly used in the art. It is sufficient to ensure that the total amount of each component meets the requirement of 100%.

[0094] In the treatment agent described in this invention, preferably,

[0095] The solvent is water; and / or,

[0096] The solvent accounts for 95 to 99.5 wt% of the total weight of the treatment agent.

[0097] The key active ingredients of the treatment agent of the present invention are fatty acid ester alkoxysulfonate, hydrocarbon amine polyether anionic surfactant, and optionally nanoparticles. Those skilled in the art know that, for the sake of convenience in transportation and storage or on-site use, various supply forms can be adopted, such as anhydrous solid form, aqueous solid form, aqueous paste form, or aqueous solution form; the aqueous solution form includes the form of a concentrated solution prepared with water, or the form of a treatment agent prepared directly to the concentration required for on-site oil displacement; there are no special requirements for the water, which can be deionized water or water containing inorganic minerals, and the water containing inorganic minerals can be tap water or formation water.

[0098] A second objective of this invention is to provide a method for preparing the soil contaminated treatment agent described in one objective of this invention, comprising the following steps:

[0099] The contaminated soil treatment agent is prepared by optionally adding nanoparticles to components including the aforementioned fatty acid ester alkoxysulfonate and hydrocarbon amine polyether anionic surfactant. Here, "thorough mixing" means that the solvent-soluble components are fully dissolved and the solvent-insoluble components are fully dispersed.

[0100] A third objective of this invention is to provide the application of the treatment agent described in one objective of this invention or the treatment agent prepared by the preparation method described in another objective of this invention in the removal of heavy metal ions from soil.

[0101] The fourth objective of this invention is to provide a method for removing heavy metal ions from soil, comprising the following steps:

[0102] The treatment agent described in one objective of the present invention or the treatment agent prepared by the preparation method described in another objective of the present invention is injected into the soil along with gas, and water is added until no foam flows out.

[0103] In this invention, the injection volume of the treatment agent is based on the main standard of no foam outflow. Preferably, the injection volume of the treatment agent is 0.5-3.0 times the pore volume of the soil to be injected. The pore volume of the soil can be calculated or measured using existing methods.

[0104] Preferably, when injecting contaminated soil,

[0105] The gas flow rate is 0.2–200 mL / min; and / or,

[0106] The gas is selected from at least one of nitrogen, air, and carbon dioxide; and / or,

[0107] The flow rate of the treatment agent is 0.1–50 mL / min; and / or,

[0108] The heavy metal ions removed from the contaminated soil are at least one of lead, chromium, cadmium, mercury, and arsenic, preferably cadmium; and / or,

[0109] The removal rate of heavy metal ions in the soil is ≥85%; the removal rate of organic pollutants in the soil is over 90%.

[0110] The fatty acid ester alkoxysulfonate and the hydrocarbon amine polyether anionic surfactant in the composition of this invention are both green and easily degradable surfactants, avoiding secondary pollution to the formation. The nanoparticles are selected from inorganic substances contained in the formation, thus also not causing secondary pollution. The hydrocarbon amine polyether anionic surfactant in this composition has multiple carboxylate groups, which can form complexes with heavy metal ions, carrying them out, and also exhibits good foaming properties. The fatty acid ester alkoxysulfonate in the composition can react with organic pollutants, exhibiting good detergency. Furthermore, the two components work synergistically, reducing the interfacial tension between organic matter and water while enhancing foaming performance. They can also interact with the nanoparticles through hydrogen bonding, stabilizing the foam film. This results in increased adsorption capacity and film strength after the system is mixed with gas to form foam, expanding the swept volume and achieving the effect of removing organic pollutants and heavy metal ion pollution from the soil.

[0111] 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.

[0112] Compared with the prior art, the present invention has the following advantages:

[0113] The treatment agent of the present invention can be applied to remove heavy and light phase organic pollutants in soil.

[0114] The treatment agent of this invention can remove more than 90% of organic pollutants in the soil and more than 85% of heavy metal ions, achieving good technical results.

[0115] The treatment agent of this invention can remove organic pollutants and heavy metal ions in soil in situ, and is simple to operate and has a lower cost. Detailed Implementation

[0116] The present invention will now be described in detail with reference to specific 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] The fatty acid ester alkoxysulfonate in the examples was prepared according to the method described in the following specific preparation example. The nanoparticles were purchased from Evonik Degussa.

[0121] The content of heavy metal ions was determined by atomic absorption spectrometry.

[0122] The content of organic pollutants in the soil was determined by gas chromatography.

[0123] The method for testing soil pore volume is as follows:

[0124] Simulated quartz sand is filled into a simulated planar model of soil. After filling the model, a vacuum pump is used to evacuate the model. Then, water is added to saturate the model (pure water is drawn into the model by itself). The volume of water drawn in is recorded as the pore volume.

[0125] Preparation Examples 1-6

[0126] A method for preparing a hydrocarbon-based amine polyether anionic surfactant includes the following steps:

[0127] a. Under a nitrogen atmosphere with 0.5 mol of potassium hydroxide, 1 mol of R2NH2 reacts sequentially with the required amounts of propylene oxide and ethylene oxide at 120 °C. After the reaction is completed, the temperature is lowered to 90 °C, low-boiling substances are removed under vacuum, and after cooling, neutralization, dehydration and other post-treatments are performed to obtain compound (A).

[0128]

[0129] b. The compound (A) obtained in step a (1 mole) is reacted with ClCH2COONa (5 moles) and sodium hydroxide (5 moles) in 1000 mL of toluene / benzene (v / v = 1) to generate compound (II). The reaction temperature is 90 °C and the reaction time is 10 hours. After acidification with 20 wt% hydrochloric acid, separation of water and inorganic salts, and removal of solvent by evaporation, the product is mixed with water and the pH of the system is adjusted to 13 with 25% sodium hydroxide aqueous solution to obtain compound (II).

[0130]

[0131] In the preparation example of hydrocarbon-based amine polyether anionic surfactant, the amounts of propylene oxide and ethylene oxide added are shown in Table 1.

[0132] Table 1

[0133]

[0134] Preparation Examples 7-12

[0135] A method for preparing fatty acid ester alkoxysulfonate includes the following steps:

[0136] a. Under the catalysis of barium sulfate catalyst (catalyst being 1 wt% of the mass of α-olefin fatty acid methyl ester) and under nitrogen protection, α-olefin fatty acid methyl ester (1 mole) was reacted sequentially with the required amounts of ethylene oxide and propylene oxide at 180 °C. After the reaction was completed, the temperature was lowered and the catalyst was filtered to obtain compound (B).

[0137]

[0138] b. Add 1 mole of compound (B) obtained in step a to a reaction vessel, add 500 mL of isopropanol as solvent and 5 mL of tert-butyl peroxide, and heat to 45°C. Prepare an aqueous solution containing 1 mole of sodium bisulfite and 0.3 moles of sodium sulfite, add it dropwise to the reaction vessel, heat to 75°C and react for 3 hours. After the reaction is completed, cool, add 25% sodium hydroxide aqueous solution to adjust the pH of the system to 13, and remove unreacted substances by chloroform extraction to obtain compound (III);

[0139]

[0140] In the preparation examples of fatty acid ester alkoxysulfonates, the amounts of propylene oxide and ethylene oxide added are shown in Table 2.

[0141] Table 2

[0142]

[0143]

Example 1

[0144] Fatty acid ester alkoxysulfonate (prepared in Preparation Example 7), hydrocarbon amine polyether anionic surfactant (prepared in Preparation Example 1), and nano-silica particles (particle size 20 nm) were dissolved in tap water at a weight ratio of 1:0.8:1 to prepare a 2 wt% aqueous solution, thus obtaining treatment agent HF-1. The specific structural composition of fatty acid ester alkoxysulfonate and hydrocarbon amine polyether anionic surfactant is shown in Table 3.

[0145]

Example 2

[0146] Fatty acid ester alkoxysulfonate (prepared in Preparation Example 8), hydrocarbon amine polyether anionic surfactant (prepared in Preparation Example 2), and nano-silica particles (particle size 20 nm) were dissolved in tap water at a weight ratio of 1:4:2 to prepare a 2 wt% aqueous solution, thus obtaining treatment agent HF-2. The specific structural composition of fatty acid ester alkoxysulfonate and hydrocarbon amine polyether anionic surfactant is shown in Table 3.

[0147]

Example 3

[0148] Fatty acid ester alkoxysulfonate (prepared in Preparation Example 9), hydrocarbon amine polyether anionic surfactant (prepared in Preparation Example 3), and nano-silica particles (particle size 20 nm) were dissolved in tap water at a weight ratio of 1:0.3:0.3 to prepare a 2 wt% aqueous solution, thus obtaining the treatment agent HF-3. The specific structural composition of the fatty acid ester alkoxysulfonate and hydrocarbon amine polyether anionic surfactant is shown in Table 3.

[0149]

Example 4

[0150] Fatty acid ester alkoxysulfonate (prepared in Preparation Example 10), hydrocarbon amine polyether anionic surfactant (prepared in Preparation Example 4), and nano-silica particles (particle size 20 nm) were dissolved in tap water at a weight ratio of 1:10:4 to prepare a 2 wt% aqueous solution, thus obtaining the treatment agent HF-4. The specific structural composition of the fatty acid ester alkoxysulfonate and hydrocarbon amine polyether anionic surfactant is shown in Table 3.

[0151]

Example 5

[0152] Fatty acid ester alkoxysulfonate (prepared in Preparation Example 11), hydrocarbon amine polyether anionic surfactant (prepared in Preparation Example 5), and nano-silica particles (particle size 20 nm) were dissolved in tap water at a weight ratio of 1:7:3 to prepare a 2 wt% aqueous solution, thus obtaining the treatment agent HF-5. The specific structural composition of the fatty acid ester alkoxysulfonate and hydrocarbon amine polyether anionic surfactant is shown in Table 3.

[0153]

Example 6

[0154] Fatty acid ester alkoxysulfonate (prepared in Preparation Example 12), hydrocarbon amine polyether anionic surfactant (prepared in Preparation Example 6), and nano-silica particles (particle size 20 nm) were dissolved in tap water at a weight ratio of 1:1:0.5 to prepare a 2 wt% aqueous solution, thus obtaining the treatment agent HF-6. The specific structural composition of the fatty acid ester alkoxysulfonate and hydrocarbon amine polyether anionic surfactant is shown in Table 3.

[0155]

Example 7

[0156] The treatment agent HF-7 was formed by combining the fatty acid ester alkoxysulfonate and the hydrocarbon amine polyether anionic surfactant from [Example 2]. The specific structural composition of the fatty acid ester alkoxysulfonate and the hydrocarbon amine polyether anionic surfactant is shown in Table 3.

[0157] Table 3 shows the structure of each component in the treatment agents in Examples 1-7.

[0158]

[0159] In Table 3, R2 and R are both straight-chain carbon chains;

[0160] In Table 3, the I:II:III mass ratio refers to the mass ratio of fatty acid ester alkoxysulfonate, hydrocarbon amine polyether anionic surfactant, and nano silica particles.

[0161]

Example 8

[0162] A planar sand-filled model with different permeabilities was constructed using quartz sand containing 800 mg / kg cadmium ions and 1000 mg / L organic pollutants (where cumene and tetrachloroethylene = 1:1 (V / V)). The upper layer had a permeability of 4000 mD, and the lower layer had a permeability of 100 mD. The treatment agents from Examples 1-7 were injected together with nitrogen for displacement at injection rates of 1.5 mL / min and 3 mL / min, respectively. After displacing 1.0 PV (i.e., the injection volume of the treatment agent was 1 times the pore volume of the soil to be injected), water was injected until no foam flowed out. The cadmium ion content and organic pollutant content in the quartz sand were measured, and the cadmium ion and organic matter removal rates were calculated. The results are shown in Table 4.

[0163] Table 4 shows the removal rates of pollutants displaced by the treatment agents in Examples 1-7.

[0164]

[0165]

Comparative Example 1

[0166] Using only the fatty acid ester alkoxysulfonate from [Examples 1-2] as the treatment agent, the pollutant displacement test was conducted in accordance with the method of [Example 8], and the results are shown in Table 5.

[0167] [Comparative Example 2]

[0168] Using only the hydrocarbon-based amine polyether anionic surfactant from [Examples 1-2] as the treatment agent, the pollutant displacement test was conducted using the same method as in [Example 8]. The results are shown in Table 5.

[0169] [Comparative Example 3]

[0170] Using only the fatty acid ester alkoxysulfonate and nano silica particles (20 nm in diameter) from [Examples 1-2] as treatment agents, the pollutant displacement test was conducted using the same method as in [Example 8]. The results are shown in Table 5.

[0171] [Comparative Example 4]

[0172] Using only the hydrocarbon-based amine polyether anionic surfactant and nano-silica particles (20 nm in diameter) from [Examples 1-2], the pollutant displacement test was conducted using the same method as in [Example 8]. The results are shown in Table 5.

[0173] [Comparative Example 5]

[0174] In Example 1, fatty acid ester alkoxysulfonate was replaced with sodium dodecyl sulfonate. Sodium dodecyl sulfonate was mixed with hydrocarbon amine polyether anionic surfactant and nano silica at a mass ratio of 1:0.8:1, and the pollutant displacement test was carried out in the same way as in Example 8. The results are shown in Table 5.

[0175] [Comparative Example 6]

[0176] The amine in the hydrocarbon amine polyether anionic surfactant in Example 2 was replaced with an amide group, and the pollutant displacement test was carried out under the same conditions as in Example 8. The results are shown in Table 5.

[0177] [Comparative Example 7]

[0178] The hydrocarbon amine polyether anionic surfactant in Example 2 was replaced with sodium aliphatic amine polyoxyethylene ether carboxylate (i.e., the structure formed after removing the -(C3H6O)- structure of the hydrocarbon amine polyether anionic surfactant in Example 2 of Formula (II) of this invention), and the pollutant displacement test was carried out using the same method as in [Example 8]. The results are shown in Table 5.

[0179] Table 5 shows the removal rates of pollutants displaced by the treatment agents in the comparative examples.

[0180]

[0181]

[0182] By comparing Comparative Examples 1-5 with Examples 1 and 2, it can be clearly seen that the fatty acid ester alkoxysulfonate and the hydrocarbon amine polyether anionic surfactant of the present invention have a synergistic effect when combined.

[0183] Furthermore, the results of Comparative Examples 6-7 show that the hydrocarbon amine polyether anionic surfactant of Formula (II) of the present invention, compared with other surfactants of similar structures, produces the best treatment agent when compounded with fatty acid ester alkoxysulfonate.

[0184] 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.

Claims

1. A contaminated soil treatment agent, comprising, by weight, the following substances: (1) 1 part fatty acid ester alkoxysulfonate (2) 0.1~50 parts of hydrocarbon amine polyether anionic surfactant (3) Optionally 0.2 to 10 parts of nanoparticles; The fatty acid ester alkoxysulfonate has the general molecular formula shown in formula (I): ； Formula (I) In formula (I), R is selected from C 10 ~C 26 Aliphatic hydrocarbon group; R' is selected from C1~C4 hydrocarbon groups; -A is selected from -(C2H4O) a -(C3H6O) b - at least one of them; wherein a is any number satisfying 0 < a ≤ 15, and b is any number satisfying 0 ≤ b ≤ 10; Y + To make the general molecular formula an electrically neutral monovalent metal cation; The hydrocarbon-based amine polyether anionic surfactant has the general molecular formula shown in formula (II): ， Equation (II) In formula (II), R2 is selected from carbon atoms with the number of carbon atoms C8~C9. 20 Saturated or unsaturated hydrocarbon groups; m, n, p, q may be the same or different, and each is an independent number from 0 to 20, and m+n≥1; X is selected from carboxylate groups; M is a cation or cationic group that makes the general formula of the molecule electrically neutral, and the two M's may be the same or different.

2. The treatment agent according to claim 1, characterized in that: In formula (II), R2 is selected from carbon atoms of C. 12 ~C 20 Saturated or unsaturated hydrocarbon groups; and / or, m, n, p, and q may be the same or different, and each is an independent number from 0 to 5, and m+n≥1.

3. The treatment agent according to claim 2, characterized in that: m+p is any number from 1 to 5; and / or, n+q is any number from 0 to 5; and / or, M is selected from alkali metal ions, NH4+ + At least one of them.

4. The treatment agent according to claim 3, characterized in that: m, n, p, q may be the same or different, each being an independent number from 0 to 2, and m+n≥1; and / or, The alkali metal ions are selected from Li + Na + K + 、Rb + At least one of them.

5. The treatment agent according to claim 1, characterized in that: The fatty acid ester alkoxysulfonate has the general molecular formula shown in formula (I): ； Formula (I) In formula (I), R' is selected from hydrocarbon groups of C1 to C2.

6. The treatment agent according to claim 5, characterized in that: The fatty acid ester alkoxysulfonate has the general molecular formula shown in formula (III): Formula (III); The R is selected from C. 12 ~C 20 aliphatic hydrocarbon groups; a is any integer from 1 to 10; b is any integer from 0 to 8; Y + ChoiceNa + , K + .

7. The treatment agent according to claim 6, characterized in that: a is any integer from 3 to 10; and / or, b is any integer from 0 to 5.

8. The treatment agent according to claim 7, characterized in that: b is 0; Y + Selected from Na + .

9. The treatment agent according to claim 8, characterized in that: The fatty acid ester alkoxysulfonate is sodium fatty acid methyl ester ethoxysulfonate.

10. The treatment agent according to claim 1, characterized in that: The nanoparticles are selected from at least one of silica, calcium carbonate, and lithium saponite; and / or, The particle size of the nanoparticles is ≤80nm.

11. The treatment agent according to claim 1, characterized in that: The weight ratio of the fatty acid ester alkoxysulfonate to the hydrocarbon amine polyether anionic surfactant in the treatment agent is 1:(0.2~10); and / or, The weight ratio of the fatty acid ester alkoxysulfonate to the nanoparticles is 1:(0.2~5).

12. The treatment agent according to claim 1, characterized in that: It also includes solvents.

13. The treatment agent according to claim 12, characterized in that: The solvent is water; and / or, The solvent accounts for 95 to 99.5 wt% of the total weight of the treatment agent.

14. A method for preparing a contaminated soil treatment agent according to any one of claims 1 to 13, comprising the following steps: The components, including the fatty acid ester alkoxysulfonate and the hydrocarbon amine polyether anionic surfactant, are fully dissolved in a solvent, and nanoparticles are optionally added; the contaminated soil treatment agent is thus prepared.

15. The application of a treatment agent according to any one of claims 1 to 13 or a treatment agent prepared by the preparation method according to claim 14 in the removal of heavy metal ions from soil.

16. A method for treating contaminated soil, comprising the following steps: Inject the treatment agent according to any one of claims 1 to 13 or the treatment agent prepared by the preparation method according to claim 14 together with gas into the contaminated soil, and then add water until no more foam flows out.

17. The method for treating contaminated soil according to claim 16, characterized in that: The injection volume of the treatment agent is 0.5-3.0 times the pore volume of the soil to be injected.

18. The processing method according to claim 17, characterized in that: When injecting contaminated soil, The gas flow rate is 0.2–200 mL / min; and / or, The gas is selected from at least one of nitrogen, air, and carbon dioxide; and / or, The flow rate of the treatment agent is 0.1–50 mL / min; and / or, The heavy metal ions removed from the contaminated soil are at least one of lead, chromium, cadmium, mercury, and arsenic.

19. The processing method according to claim 18, characterized in that: The heavy metal ions removed from the contaminated soil were cadmium.

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