Carbonate eluting agent as well as preparation method and application thereof

Abstract

The invention relates to a carbonate eluting agent and a preparation method and application thereof, and belongs to the technical field of radionuclide contaminated soil remediation and treatment. The carbonate eluting agent provided by the invention comprises carbonate, bicarbonate, an oxidizing agent, a eutectic solvent and an anionic surfactant, the oxidizing agent comprises sodium chlorite and hydrogen peroxide; the eutectic solvent comprises choline chloride and urea; the molar ratio of the carbonate to the bicarbonate to the hydrogen peroxide is (0.005 to 0.025) to (0.025 to 0.1) to (0.3 to 0.5); the molar ratio of choline chloride to urea in the deep eutectic solvent is (0.8-1.2): (0.8-1.2). The prepared eluting agent is green and mild, the removal rate of uranium in soil is remarkably increased by regulating and controlling the appropriate component proportion, and the eluting agent has important significance on safe development of the nuclear power industry and protection and treatment of the radioactive pollution environment.

Description

Technical Field

[0001] The present invention relates to the technical field of radionuclide contaminated soil remediation and treatment, and in particular to a carbonate eluting agent and a preparation method and application thereof. Background Art

[0002] With the increasing processing and use of radioactive elements, the pollution problem caused by uranium-containing minerals to the environment is becoming more and more serious. Due to the lack of protection in the uranium mining and smelting industry, some uranium-containing mineral powders settle into the surrounding soil environment during transportation and production, causing varying degrees of soil uranium contamination. Uranium not only has radioactive damage to organisms, but also has heavy metal chemical toxicity. It is absorbed by plants and animals in the environment and enters the ecosystem through the food chain, which may affect the growth and development of organisms and cause genetic damage.

[0003] At present, due to the increasingly prominent problem of soil uranium contamination in some decommissioned uranium mines, it is urgent and necessary to carry out research on the restoration and treatment technology of radioactive nuclide uranium contaminated soil, which is of great significance to the ecological environment management and protection of uranium mines in my country. Chemical leaching technology has been widely studied due to its advantages such as simple operation, wide application range, and engineering application. However, the existing technology uses strong acids and strong bases as leaching agents, which have a great impact on the composition and structure of the soil, and is not conducive to the environmental ecological restoration of the soil.

[0004] Therefore, actively developing and preparing new uranium-contaminated soil eluents that are green, mild, efficient, clean, and do not destroy the soil component structure is of great significance to the safe development of the nuclear power industry and the protection and remediation of the radioactively contaminated environment. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a carbonate eluent and its preparation method and application. The carbonate eluent provided by the present invention has a high removal rate of uranium in soil, is mild and environmentally friendly, and does not damage the soil structure to restore its use function.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a carbonate eluent, comprising the following components: a carbonate, a bicarbonate, an oxidant, a deep eutectic solvent, and an anionic surfactant; the oxidant comprises sodium chlorite and hydrogen peroxide; the deep eutectic solvent comprises choline chloride and urea; the molar ratio of the carbonate, the bicarbonate and the hydrogen peroxide is carbonate:bicarbonate:hydrogen peroxide=(0.05-0.25):(0.25-1):(3-5); the molar ratio of choline chloride and urea in the deep eutectic solvent is (0.8-1.2):(0.8-1.2).

[0008] The present invention adopts a combination of carbonate, bicarbonate and oxidant to leach and remove uranium in the soil: carbonate, as a milder eluent, can better protect the soil structure during the elution process, and uranyl ions can form soluble complexes with carbonates in the system and be removed from soil particles; the addition of hydrogen peroxide promotes the oxidation of insoluble tetravalent uranium in the soil into soluble hexavalent uranium and dissolves it from the soil, and compared with oxidants such as potassium permanganate and potassium dichromate, the use of hydrogen peroxide avoids secondary pollution to the soil while ensuring the oxidation effect.

[0009] The specific ratio of carbonate, bicarbonate and oxidant in the present invention can significantly improve the dissolution and removal effect of the eluent on uranium in the soil. When the ratio of the three is outside this range, the removal rate of uranium in the soil by the eluent may be significantly reduced when used.

[0010] The present invention also uses a low eutectic solvent composed of choline chloride and urea, which, as a strong electron donor, is very easy to coordinate with uranyl ions, reducing the frequency of uranium that has entered the solution being adsorbed back to the soil surface. At the same time, the addition of anionic surfactants reduces the surface tension of soil particles, promotes soil dissociation and the dissolution of uranyl ions, and further improves the removal efficiency. The above-mentioned specific low eutectic solvent system and ratio can significantly improve the removal rate of uranium in the soil by the eluent and significantly improve the repair effect of the eluent on the soil; changing the system ratio may cause the removal effect of uranium to deteriorate significantly.

[0011] The above-mentioned eluent system provided by the present invention has green and mild ingredients and a buffer system. It can reduce the damage to the soil structure during the elution process and is more conducive to restoring the use function of the soil. When the initial concentration of uranium in the soil is 735.17 mg / kg, the removal rate of uranium in the soil can reach more than 85%, and it has extremely high application potential in the restoration of heavily uranium-contaminated soil.

[0012] Preferably, the molar ratio of sodium chlorite to hydrogen peroxide is 0.3:(3-5).

[0013] Further preferably, the molar ratio of the carbonate, bicarbonate and hydrogen peroxide is carbonate:bicarbonate:hydrogen peroxide=0.1:0.5:4.

[0014] Preferably, the molar ratio of choline chloride to urea is 1:1.

[0015] The carbonate eluent system under the above-mentioned component ratio can achieve the best removal effect of uranium in the soil, and the removal rate of uranium in the soil can reach more than 93%.

[0016] Preferably, the carbonate is potassium carbonate, and the bicarbonate is potassium bicarbonate.

[0017] A leaching system of potassium carbonate and potassium bicarbonate is used, in which the presence of potassium ions can promote the migration of uranyl ions inside soil particles and better dissolve uranium in the soil.

[0018] Further preferably, the mass ratio of the potassium carbonate to the deep eutectic solvent is (0.691-3.456):(2-6). As a preferred embodiment, the mass ratio of the potassium carbonate to the deep eutectic solvent is (0.691-3.456):4.

[0019] Preferably, the anionic surfactant includes sodium dodecylbenzene sulfonate and sodium dodecyl sulfate.

[0020] More preferably, the molar ratio of the carbonate, sodium dodecylbenzene sulfonate and sodium dodecyl sulfate is carbonate: sodium dodecylbenzene sulfonate: sodium dodecyl sulfate = (5-25): (0.44-0.47): (0.47-0.50).

[0021] The combined effect of the low eutectic solvent and the anionic surfactant within the above dosage range can significantly improve the removal effect of the carbonate eluent of the present invention on uranium in soil.

[0022] In a second aspect, the present invention provides a method for preparing the above-mentioned carbonate eluent, comprising the following steps:

[0023] (1) dissolving carbonate and bicarbonate in water, then adding an oxidant and mixing well to obtain solution A;

[0024] (2) adding a low eutectic solvent and an anionic surfactant into the solution A to dissolve and mix well, thereby obtaining the carbonate eluent.

[0025] Preferably, the preparation method of the low eutectic solvent is as follows: choline chloride and urea are melted and mixed in a boiling water bath, and then cooled and dried to obtain the low eutectic solvent.

[0026] Preferably, the dissolving and mixing method includes ultrasound and stirring; the stirring speed is 200-800r / min.

[0027] In a third aspect, the present invention provides the use of the above-mentioned carbonate eluent in the remediation of uranium contaminated soil.

[0028] As a preferred solution, the application comprises the following steps:

[0029] Add the eluent to the ground and screened uranium-contaminated soil. The ratio of soil to eluent is 1t:1-3m 3 ; performing elution treatment at room temperature, and then mixing, stirring, and mud-water separation to complete the remediation of the uranium-contaminated soil.

[0030] When the carbonate eluent provided by the present invention is used, the concentration is about 0.005-0.025 mol / L potassium carbonate, and the highest uranium removal rate can be achieved after 8 hours of elution treatment.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention is based on the existing research on the concept of chemical leaching technology for contaminated soil. By screening the proportion of carbonate, oxidant, solubilizer, etc., a carbonate leaching agent is obtained. The preparation avoids the damage to the soil structure caused by the use of strong acid and strong alkali (such as nitric acid, sodium hydroxide, etc.), and can effectively remove uranium in the soil. The maximum removal rate of uranium in contaminated soil by the carbonate agent reaches 93.02%. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the carbonate eluent prepared in Example 1;

[0034] Figure 2 The diagram shows the remediation effect of the eluents in Example 1-5 (ae) and Comparative Example 1-7 (f) on uranium contaminated soil. DETAILED DESCRIPTION

[0035] In order to better illustrate the purpose, technical scheme and advantages of the present invention, the present invention will be further described below in conjunction with specific examples. The test methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0036] Example 1

[0037] An embodiment of the carbonate eluent of the present invention, the preparation method of the carbonate eluent of this embodiment is as follows:

[0038] (1) 0.005 mol potassium carbonate and 0.025 mol potassium bicarbonate were dispersed in 900 mL of deionized water, and ultrasonicated for 30 min and stirred for 1 h; 0.03 mol sodium chlorite was added under magnetic stirring at 500 r / min to completely dissolve all solid particles, and hydrogen peroxide solution was slowly added until the hydrogen peroxide content was 0.3 mol to obtain a mixed solution A;

[0039] (2) After mixing 1 mol of choline chloride and 1 mol of urea, the mixture was stirred and heated in a boiling water bath for 1 h until all the solids were dissolved. After the solution was cooled to room temperature, it was placed in a vacuum drying oven and dried for 12 h to obtain a viscous liquid low eutectic solvent;

[0040] (3) Add 4 g of the low eutectic solvent to the mixed solution A, and after it is evenly dispersed, add 0.16 g of sodium dodecylbenzene sulfonate and 0.14 g of sodium dodecyl sulfate, and continue stirring until all the solid particles are completely dissolved to obtain the carbonate eluent, such as Figure 1 shown.

[0041] Example 2

[0042] An embodiment of the carbonate eluent of the present invention, the preparation method of the carbonate eluent of this embodiment is as follows:

[0043] (1) 0.01 mol potassium carbonate and 0.05 mol potassium bicarbonate were dispersed in 900 mL of deionized water, and ultrasonicated for 30 min and stirred for 1 h; 0.03 mol sodium chlorite was added under magnetic stirring at 500 r / min to completely dissolve all solid particles, and hydrogen peroxide solution was slowly added until the hydrogen peroxide content was 0.4 mol to obtain a mixed solution A;

[0044] (2) After mixing 1 mol of choline chloride and 1 mol of urea, the mixture was stirred and heated in a boiling water bath for 1 h until all the solids were dissolved. After the solution was cooled to room temperature, it was placed in a vacuum drying oven and dried for 12 h to obtain a viscous liquid low eutectic solvent;

[0045] (3) 4 g of a low eutectic solvent was added to the mixed solution A, and after being evenly dispersed, 0.16 g of sodium dodecylbenzene sulfonate and 0.14 g of sodium dodecyl sulfate were added, and stirring was continued until all solid particles were completely dissolved to obtain the carbonate eluent.

[0046] Example 3

[0047] An embodiment of the carbonate eluent of the present invention, the preparation method of the carbonate eluent of this embodiment is as follows:

[0048] (1) 0.025 mol potassium carbonate and 0.1 mol potassium bicarbonate were dispersed in 900 mL of deionized water, and ultrasonicated for 30 min and stirred for 1 h; 0.03 mol sodium chlorite was added under magnetic stirring at 500 r / min to completely dissolve all solid particles, and hydrogen peroxide solution was slowly added until the hydrogen peroxide content was 0.5 mol to obtain a mixed solution A;

[0049] (2) After mixing 1 mol of choline chloride and 1 mol of urea, the mixture was stirred and heated in a boiling water bath for 1 h until all the solids were dissolved. After the solution was cooled to room temperature, it was placed in a vacuum drying oven and dried for 12 h to obtain a viscous liquid low eutectic solvent;

[0050] (3) 4 g of a low eutectic solvent was added to the mixed solution A, and after being evenly dispersed, 0.16 g of sodium dodecylbenzene sulfonate and 0.14 g of sodium dodecyl sulfate were added, and stirring was continued until all solid particles were completely dissolved to obtain the carbonate eluent.

[0051] Example 4

[0052] An embodiment of the carbonate eluent of the present invention, the preparation method of the carbonate eluent described in this embodiment is different from that of Example 2 only in that 0.8 mol of choline chloride and 1.2 mol of urea are used to prepare the low eutectic solvent in step (2).

[0053] Example 5

[0054] An embodiment of the carbonate eluent of the present invention, the preparation method of the carbonate eluent described in this embodiment is different from that of Example 2 only in that 1.2 mol of choline chloride and 0.8 mol of urea are used to prepare the low eutectic solvent in step (2).

[0055] Comparative Example 1

[0056] A washing agent is prepared by the following method:

[0057] (1) 0.003 mol potassium carbonate and 0.02 mol potassium bicarbonate were dispersed in 900 mL of deionized water, and ultrasonicated for 30 min and stirred for 1 h; 0.03 mol sodium chlorite was added under magnetic stirring at 500 r / min to completely dissolve all solid particles, and hydrogen peroxide solution was slowly added until the hydrogen peroxide content was 0.5 mol to obtain a mixed solution A;

[0058] (2) After mixing 1 mol of choline chloride and 1 mol of urea, the mixture was stirred and heated in a boiling water bath for 1 h until all the solids were dissolved. After the solution was cooled to room temperature, it was placed in a vacuum drying oven and dried for 12 h to obtain a viscous liquid low eutectic solvent;

[0059] (3) 4 g of a low eutectic solvent was added to the mixed solution A, and after being evenly dispersed, 0.16 g of sodium dodecylbenzene sulfonate and 0.14 g of sodium dodecyl sulfate were added, and stirring was continued until all solid particles were dissolved to obtain an eluent.

[0060] Comparative Example 2

[0061] A washing agent is prepared by the following method:

[0062] (1) 0.06 mol potassium carbonate and 0.1 mol potassium bicarbonate were dispersed in 900 mL of deionized water, and ultrasonicated for 30 min and stirred for 1 h; 0.03 mol sodium chlorite was added under magnetic stirring at 500 r / min to completely dissolve all solid particles, and hydrogen peroxide solution was slowly added until the hydrogen peroxide content was 0.2 mol to obtain a mixed solution A;

[0063] (2) After mixing 1 mol of choline chloride and 1 mol of urea, the mixture was stirred and heated in a boiling water bath for 1 h until all the solids were dissolved. After the solution was cooled to room temperature, it was placed in a vacuum drying oven and dried for 12 h to obtain a viscous liquid low eutectic solvent;

[0064] (3) 4 g of a low eutectic solvent was added to the mixed solution A, and after being evenly dispersed, 0.16 g of sodium dodecylbenzene sulfonate and 0.14 g of sodium dodecyl sulfate were added, and stirring was continued until all solid particles were dissolved to obtain an eluent.

[0065] Comparative Example 3

[0066] A washing agent is prepared by the following method:

[0067] (1) 0.01 mol potassium carbonate and 0.05 mol potassium bicarbonate were dispersed in 900 mL of deionized water, ultrasonicated for 30 min, and stirred for 1 h to obtain a mixed solution A;

[0068] (2) After mixing 1 mol of choline chloride and 1 mol of urea, the mixture was stirred and heated in a boiling water bath for 1 h until all the solids were dissolved. After the solution was cooled to room temperature, it was placed in a vacuum drying oven and dried for 12 h to obtain a viscous liquid low eutectic solvent;

[0069] (3) 4 g of a low eutectic solvent was added to the mixed solution A, and after being evenly dispersed, 0.16 g of sodium dodecylbenzene sulfonate and 0.14 g of sodium dodecyl sulfate were added, and stirring was continued until all solid particles were dissolved to obtain an eluent.

[0070] Comparative Example 4

[0071] A washing agent is prepared by the following method:

[0072] 0.01 mol potassium carbonate and 0.05 mol potassium bicarbonate were dispersed in 900 mL of deionized water, ultrasonicated for 30 min, and stirred for 1 h; 0.03 mol sodium chlorite was added under magnetic stirring at 500 r / min to completely dissolve all solid particles, and hydrogen peroxide solution was slowly added until the hydrogen peroxide was 0.4 mol to obtain an eluent.

[0073] Comparative Example 5

[0074] The only difference between Comparative Example 5 and Example 3 is that in step (2), 1 mol of choline chloride and 1.8 mol of urea are used to prepare the deep eutectic solvent.

[0075] Comparative Example 6

[0076] The only difference between Comparative Example 6 and Example 3 is that in step (2), 1.8 mol of choline chloride and 1 mol of urea are used to prepare the low eutectic solvent.

[0077] Comparative Example 7

[0078] A washing agent is prepared by the following method:

[0079] (1) 0.01 mol potassium carbonate and 0.05 mol potassium bicarbonate were dispersed in 900 mL of deionized water, and ultrasonicated for 30 min and stirred for 1 h; 0.03 mol sodium chlorite was added under magnetic stirring at 500 r / min to completely dissolve all solid particles, and hydrogen peroxide solution was slowly added until the hydrogen peroxide content was 0.4 mol to obtain a mixed solution A;

[0080] (2) After mixing 1 mol of choline chloride and 1 mol of ethylene glycol, the mixture was stirred and heated in a boiling water bath for 1 h until all the solids were dissolved. After the solution was cooled to room temperature, it was placed in a vacuum drying oven and dried for 12 h to obtain a viscous liquid low eutectic solvent;

[0081] (3) 4 g of a low eutectic solvent was added to the mixed solution A, and after being evenly dispersed, 0.16 g of sodium dodecylbenzene sulfonate and 0.14 g of sodium dodecyl sulfate were added, and stirring was continued until all solid particles were dissolved to obtain an eluent.

[0082] Effect example

[0083] In order to explore the restoration effect of the carbonate eluent provided by the present invention on the heavily uranium contaminated soil, the eluents in the examples and comparative examples were used for the elution restoration of the heavily uranium contaminated soil. The specific test steps are as follows:

[0084] The eluent was added to the uranium-contaminated soil after grinding and screening. The initial uranium concentration in the soil was 735.17 mg / kg. The ratio of soil to eluent was 1t:2m 3 ; Carry out elution treatment at room temperature, then mix, stir, separate mud and water to complete soil remediation;

[0085] During the 24-hour treatment period, samples were taken to determine the uranium concentration in the soil and the uranium removal rate was calculated. The results are as follows: Figure 2 .in Figure 2 - (a)-(e) are the removal rates of uranium in contaminated soil by carbonate eluents in Examples 1-5 at different elution times; Figure 2-(f) is a comparison of the removal rate of uranium in contaminated soil by the eluents in Comparative Examples 1-7 at different elution times with that of Example 2.

[0086] Depend on Figure 2 It can be seen that:

[0087] (1) After 8 hours of elution treatment using the eluents of each embodiment and comparative example, the removal rate of uranium in the soil reached the highest point. The carbonate eluents in the embodiments had significantly better remediation effects on uranium-contaminated soil than the eluents in the comparative examples. Among them, the solution adopted in Example 2 had the best effect.

[0088] The removal rate of uranium in the soil by the carbonate eluent of Example 1 can reach up to 86.71%, and then the removal rate fluctuates around 85%; the removal rate of uranium in the soil by the carbonate eluent of Example 2 can reach up to 93.02%, and then the removal rate fluctuates around 92%; the removal rate of uranium in the soil by the carbonate eluent of Example 3 can reach up to 89.42%, and then the removal rate fluctuates around 87%; the removal rate of uranium in the soil by the carbonate eluent of Example 4 can reach up to 90.11%, and then the removal rate fluctuates around 89%; the removal rate of uranium in the soil by the carbonate eluent of Example 5 can reach up to 91.26%, and then the removal rate fluctuates around 90%.

[0089] (2) Compared with the embodiment, the eluents in Comparative Examples 1, 2 and 3 respectively adjusted the dosage ratio of potassium carbonate / potassium bicarbonate, the dosage ratio of potassium carbonate / hydrogen peroxide and did not add an oxidant, which fell outside the scope of the present invention. Under the same treatment conditions, the uranium removal rate of Comparative Example 1 reached a maximum of 64.67%, and then the removal rate fluctuated around 61%; the uranium removal rate in Comparative Example 2 reached a maximum of 71.72%, and then the removal rate fluctuated around 68%; the uranium removal rate in Comparative Example 3 was only 43.19% at most, and then the removal rate fluctuated around 40%; all of which were significantly lower than the data in the embodiment. It can be seen that the specific dosage ratio of potassium carbonate / potassium bicarbonate / oxidant in the present invention can accelerate the migration of uranyl ions inside soil particles, and better promote the oxidation of insoluble tetravalent uranium in the soil to soluble hexavalent uranium and dissolve it from the soil, thereby significantly improving the removal effect of the eluent on uranium in the soil.

[0090] (4) Compared with the embodiment, the use conditions of the low eutectic solvent in the eluent were changed in Comparative Examples 4-7: under the same soil treatment conditions, the eluent in Comparative Example 4 did not add a low eutectic solvent and anionic surfactant, and the uranium removal rate reached a maximum of 66.51%, and then the removal rate fluctuated around 63%; in Comparative Example 5, the dosage ratio was adjusted, the dosage of choline chloride was too high, and the uranium removal rate in the soil reached a maximum of 74.15%, and then the removal rate fluctuated around 70%; in Comparative Example 6, the dosage ratio was adjusted, the dosage of urea was too high, and the uranium removal rate in the soil reached a maximum of 78.49%, and then the removal rate fluctuated around 75%; in Comparative Example 7, the choline chloride / urea system was replaced with choline chloride / ethylene glycol, and the uranium removal rate in the soil reached a maximum of 69.83%, and then the removal rate fluctuated around 65%. It can be seen that the system and proportion of the low eutectic solvent defined in the present invention are more conducive to coordination with uranyl ions, reducing the re-adsorption of dissolved uranium back to the soil surface, and significantly improving the remediation effect of the eluent on uranium-contaminated soil.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A carbonate eluent, It is characterized in that The invention comprises the following components: carbonate, bicarbonate, oxidant, low eutectic solvent and anionic surfactant; the oxidant comprises sodium chlorite and hydrogen peroxide; the low eutectic solvent comprises choline chloride and urea; the molar ratio of the carbonate, bicarbonate and hydrogen peroxide is carbonate:bicarbonate:hydrogen peroxide=(0.05-0.25):(0.25-1):(3-5); the molar ratio of choline chloride and urea in the low eutectic solvent is (0.8-1.2):(0.8-1.2).

2. The carbonate eluent according to claim 1, It is characterized in that The molar ratio of sodium chlorite to hydrogen peroxide is 0.3:(3-5).

3. The carbonate eluent according to claim 1, It is characterized in that The molar ratio of the choline chloride to the urea is 1:

1.

4. The carbonate eluent according to claim 1, It is characterized in that The carbonate is potassium carbonate, and the bicarbonate is potassium bicarbonate.

5. The carbonate eluent as claimed in claim 4, It is characterized in that The mass ratio of the potassium carbonate to the low eutectic solvent is (0.691-3.456):(2-6).

6. The carbonate eluent according to claim 1, It is characterized in that The anionic surfactants include sodium dodecylbenzene sulfonate and sodium dodecyl sulfate.

7. The carbonate eluent according to claim 6, It is characterized in that The molar ratio of the carbonate, sodium dodecylbenzene sulfonate and sodium dodecyl sulfate is carbonate: sodium dodecylbenzene sulfonate: sodium dodecyl sulfate = (5-25): (0.44-0.47): (0.47-0.50).

8. A method for preparing a carbonate eluent according to any one of claims 1 to 7, It is characterized in that The following steps are involved: (1) dissolving carbonate and bicarbonate in water, then adding an oxidant and mixing well to obtain solution A; (2) adding a low eutectic solvent and an anionic surfactant into the solution A to dissolve and mix well, thereby obtaining the carbonate eluent.

9. The method for preparing the carbonate eluent according to claim 8, It is characterized in that The preparation method of the low eutectic solvent is as follows: choline chloride and urea are melted and mixed in a boiling water bath, and then cooled and dried to obtain the low eutectic solvent.

10. Use of the carbonate eluent according to any one of claims 1 to 7 in remediation of uranium contaminated soil.

Images