Method for removing uranyl ions from a solution using a mesoporous microsphere composite material

Abstract

The application discloses a method for removing uranyl ions in a solution by using a mesoporous microsphere composite material, and belongs to the field of radioactive waste treatment. The method comprises the following steps: firstly, performing molecular pre-assembly on citric acid by an ethylenediamine-mediated cross-linking reaction before a condensation reaction of the silica, so as to construct a covalent bridge between the organic molecules and the forming silica network, and obtaining a citric acid ligand solution; then synthesizing unmodified mesoporous silica microspheres by a Stober method with precise control; thirdly, reacting the mesoporous silica microspheres with the citric acid derivative, so as to initiate the condensation of the silica and the encapsulation of the organic component; fourthly, attaching the citric acid derivative to the outer surface; and finally, obtaining the mesoporous silica composite material and adsorbing the uranyl ion acid solution. The method has the mutual synergy of the citric acid derivative and the silica carrier, the composite material has high binding performance with the uranyl ions, and high adsorption capacity is exhibited.

Description

Technical Field

[0001] This invention relates to the field of radioactive waste treatment, and specifically to a method for removing uranyl ions from a solution using a mesoporous microsphere composite material. Background Technology

[0002] Nuclear energy has rapidly developed as an important low-carbon energy solution, significantly alleviating global energy security issues and carbon emission pressures. However, uranium-containing wastewater generated during uranium mining, nuclear fuel preparation, and spent fuel reprocessing has become an increasingly serious ecological hazard, mainly due to the combined chemical nephrotoxicity and long-term radioactive hazards of uranium. Water-soluble uranium(VI) is particularly concerning, as it has strong migration capabilities in aquatic systems and easily accumulates along the food chain, ultimately threatening human health through groundwater pollution and agricultural irrigation. Among various remediation technologies, adsorption has become one of the mainstream technologies due to its simplicity, low cost, and applicability to complex matrix systems. Although traditional adsorbents such as activated carbon and zeolites, as well as advanced porous materials such as metal-organic frameworks / covalent organic frameworks, have been proven to have uranium(VI) capture capabilities, their practical applications are often limited by low selectivity, performance highly dependent on pH, and insufficient binding sites. This technological gap highlights the necessity of adsorbent innovation through rational structural design and performance optimization.

[0003] Silica-based adsorbents are promising candidates for adsorption materials due to their excellent chemical inertness, mechanical strength, and economical synthesis processes. The inherent advantages of porous silica structures—especially their ultra-high specific surface area and tunable mesoporous structure—provide numerous accessible binding sites for uranium(VI) coordination reactions. Furthermore, silica-based materials can be functionalized in diverse ways through silane coupling reactions, polymer grafting, or heteroatom doping, a characteristic crucial for tailoring uranium adsorption performance and selectivity. Summary of the Invention

[0004] The purpose of this invention is to provide a highly efficient and economical method for uranium ion adsorption, solving the problems of low uranium adsorption efficiency and complex operation in existing technologies.

[0005] This invention provides a method for removing uranyl ions from solution based on mesoporous microsphere composite materials, comprising the following steps:

[0006] Step 1: Citric acid is pre-assembled via an ethylenediamine-mediated cross-linking reaction to obtain a pre-synthesized ligand solution;

[0007] Step 2: Synthesize unmodified mesoporous silica microspheres using the Stuber process;

[0008] Step 3: Disperse the unmodified mesoporous silica microspheres in deionized water by ultrasonication to form a stable suspension;

[0009] Step 4: Add the suspension to the CTAB template system, and after equilibration for a period of time, add tetraethyl orthosilicate and the pre-synthesized ligand solution in sequence to carry out the reaction;

[0010] Step 5: After the reaction is complete, the product is collected by centrifugation and dispersed in deionized water. A mineralization promoter and a pre-synthesized ligand solution are added, and the mixture is then filtered, washed, and dried to obtain a mesoporous microsphere composite material.

[0011] Step 6: Place the mesoporous microsphere composite material into an acidic solution of uranyl ions to adsorb the uranyl ions.

[0012] Furthermore, in step 1, the molecular pre-assembly of citric acid via an ethylenediamine-mediated cross-linking reaction specifically involves:

[0013] Step 1.1: Dissolve citric acid and ethylenediamine in deionized water, mix thoroughly to obtain a homogeneous precursor solution;

[0014] Step 1.2: The homogeneous precursor solution was transferred to a reaction vessel for hydrothermal reaction. After the reaction was completed, it was cooled to room temperature to obtain the pre-synthesized ligand solution.

[0015] Further, the mass-to-volume ratio of citric acid to ethylenediamine is 1:1~1.5; the concentration of citric acid is 0.15~0.25 mol / L; the concentration of ethylenediamine is 0.5~1 mol / L; the mixing conditions are stirring at 800~850 r / min for 30~45 min at a temperature of 55~70℃; in step 1.2, the hydrothermal reaction temperature is 150~155℃ and the time is 5~6 h.

[0016] Further, in step 2, the synthesis of unmodified mesoporous silica microspheres specifically involves:

[0017] Step 2.1: Add tetraethyl orthosilicate to a ternary solvent system for hydrolysis;

[0018] Step 2.2: Unmodified mesoporous silica microspheres are obtained by filtration, washing, and drying.

[0019] Further, in step 2.1, the concentration of tetraethyl orthosilicate is 0.25~0.3mol / L; the ternary solvent system is anhydrous ethanol, deionized water and ammonia water, with a volume ratio of 7.4:1:0.5; the hydrolysis time is 1~1.2h; in step 2.2, the drying temperature is 40~60℃ and the time is 2~3h.

[0020] Furthermore, in step 3, the concentration of the unmodified mesoporous silica microspheres is 4.5~5 mg / mL.

[0021] Further, in step 4, the mass ratio of the CTAB template agent to the unmodified mesoporous silica microspheres is 4~4.2:1; the CTAB template system is a solution of hexadecyltrimethylammonium bromide, water, ethanol, and sodium hydroxide; the concentration of hexadecyltrimethylammonium bromide in the CTAB template system is 0.009~0.01mol / L, and the volume ratio of water, ethanol, and sodium hydroxide solution is 52~55:15~20:1.

[0022] Further, in step 4, the equilibration time is 30-45 min; after the mixed solution is equilibrated, the volume ratio of tetraethyl orthosilicate to sodium hydroxide solution is 0.14-0.16:1, and the ratio of ligand solution to sodium hydroxide solution is 3-5:1; after adding tetraethyl orthosilicate and the pre-synthesized ligand solution, the reaction is carried out at a stirring rate of 1000-1200 r / min for 6-7 h.

[0023] Further, in step 5, the centrifugation rate is 800~1000 r / min; the mass-volume ratio of the product to deionized water is 4.5~5 mg / mL; the mineralization promoter is sodium carbonate, and the concentration of the mineralization promoter is 0.1~0.2 mol / L; the volume ratio of the pre-synthesized ligand solution to deionized water is 1:5~6 mL; the reaction temperature is 45~55℃, and the time is 10~12 h.

[0024] Further, the mass-to-volume ratio of the mesoporous microsphere composite material to the solution is 1g:150~300mL; the uranyl ion-containing acid solution is uranyl nitrate solution; the pH of the uranyl ion-containing acid solution is 1~4. The pH is adjusted using 15M nitric acid or sodium hydroxide. The adsorption conditions are stirring at 200~300 r / min for 6~8 h.

[0025] The beneficial effects of this invention are as follows:

[0026] The synergistic interaction between the citric acid derivative ligand and the silica support in this invention results in a material with high binding performance to uranyl ions. In multi-component systems containing multiple competing cations, the composite material exhibits excellent adsorption selectivity for uranium(VI). Besides the coordination chemistry of the embedded ligands themselves, the unique nano-confined environment within the mesoporous channels is considered crucial for enhancing adsorption performance and stability. The spatially confined channels allow for the pre-assembly of ligand molecules, increasing the effective local concentration of the ligands and orienteding functional groups to form configurations more favorable for uranium(VI) coordination. Furthermore, this confinement effect stabilizes the formed uranium-ligand complexes, achieving stabilization by reducing the conformational freedom of the ligands after metal binding and by constructing a local microenvironment to protect the complex. The synergistic effect between the customized ligand chemistry and the physicochemical properties of the mesoscopic confinement is a key reason why the composite material exhibits high adsorption capacity, high selectivity, and excellent regeneration performance. The in-situ confinement strategy proposed in this study is also applicable to various chelating ligands containing carboxyl, amino, or other functional groups, providing a general technical platform for the rational design of advanced adsorbents targeting specific radionuclides or heavy metals. Through the coordination of the ligands, the composite material exhibits a high adsorption capacity for uranium(VI), reaching 188.3 mg / g. Attached Figure Description

[0027] Figure 1 These are scanning electron microscope images of the mesoporous microsphere composite material at different magnifications according to the present invention;

[0028] Figure 2 The images show the FTIR spectra of the mesoporous microsphere composite material and the unmodified mesoporous microsphere composite material of the present invention.

[0029] Figure 3 The diagram shows the kinetic adsorption curve of the mesoporous microsphere composite material of the present invention.

[0030] Figure 4 This is a selective adsorption diagram of the mesoporous microsphere composite material of the present invention. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to specific embodiments. The examples given are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0032] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods.

[0033] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0034] This invention discloses an in-situ encapsulation strategy to construct organically embedded mesoporous silica microspheres (OMSS) for efficient extraction of uranium (VI) from solution. By confining citric acid derivatives within 2.52 nm mesoporous channels during the self-assembly process, the resulting composite material exhibits excellent binding capacity for uranium (VI), with the OMSS achieving an uranium (VI) adsorption capacity of 188.3 mg / g.

[0035] The in-situ encapsulation strategy provided by this invention includes the following steps: pre-assembling precursor materials; synthesizing unmodified mesoporous silica microspheres; reacting the pre-synthesized ligand solution with the silica microspheres to initiate silica condensation and encapsulation of organic components; and adding a mineralization promoter and the pre-synthesized ligand solution. The mesoporous microsphere composite material of this invention has citric acid derivatives embedded within it, and citric acid derivatives also adhered to its outer surface. The inner and outer surfaces of the composite material can simultaneously adsorb uranyl ions, greatly improving the adsorption capacity.

[0036] The method for removing uranyl ions from solution using the mesoporous microsphere composite material of the present invention is as follows:

[0037] Step 1: Pre-assemble citric acid molecules via ethylenediamine-mediated cross-linking reaction;

[0038] Step 1.1: Dissolve citric acid and ethylenediamine in deionized water, mix thoroughly to obtain a homogeneous precursor solution;

[0039] Step 1.2: The homogeneous precursor solution was transferred to a reaction vessel for hydrothermal reaction. After the reaction was completed, it was cooled to room temperature to obtain the pre-synthesized ligand solution.

[0040] Step 2: Synthesize unmodified mesoporous silica microspheres using the Stuber process;

[0041] Step 3: Disperse the unmodified mesoporous silica microspheres in deionized water by ultrasonication to form a stable suspension;

[0042] Step 4: Add the suspension to the CTAB template system, and after equilibration for a period of time, add tetraethyl orthosilicate and the pre-synthesized ligand solution in sequence to carry out the reaction;

[0043] Step 5: After the reaction is complete, the product is collected by centrifugation and dispersed in deionized water. A mineralization promoter and a pre-synthesized ligand solution are added, and the mixture is then filtered, washed, and dried to obtain a mesoporous microsphere composite material.

[0044] Step 6: Place the mesoporous microsphere composite material into an acidic solution of uranyl ions to adsorb the uranyl ions.

[0045] The above method involves four factors affecting the pre-assembly process of the precursor material: solid-liquid ratio, solution concentration, preparation temperature, and reaction time.

[0046] In the method of step 1 above, the solid-liquid ratio, citric acid (s, g): ethylenediamine (l, mL), can be 1:1 to 1.5.

[0047] In the method of step 1 above, the concentration of the solution, the concentration of citric acid can be 0.15~0.25mol / L, and the concentration of ethylenediamine can be 0.5~1mol / L.

[0048] In the method described in step 1 above, the preparation temperature can be a constant temperature water bath of 55~70℃ and the rotation speed is 800~850r / min.

[0049] In step 1 above, the reaction time is 30-45 minutes; then the precursor solution is transferred to the reaction vessel.

[0050] In the method described in step 1 above, the preparation temperature can be 150~155℃.

[0051] The reaction time in step 1 above is 5-6 hours, followed by natural cooling.

[0052] In the method described in step 1 above, the reaction solvent is deionized water.

[0053] The method in step 2 above describes the influence of two factors on the solution concentration and reaction time during the synthesis of unmodified mesoporous silica microspheres.

[0054] In step 2 above, the solution concentration, specifically the TEOS concentration, can be 0.25~0.3 mol / L.

[0055] In step 2 above, the solution solvent is a ternary mixture of anhydrous ethanol, deionized water and ammonia water, with a volume ratio of 7.4:1:0.5.

[0056] In the method of step 2 above, the room temperature is 25~35℃, the reaction time can be 1~1.2h, and the rotation speed is 500~550r / min.

[0057] The method in step 2 above involves collecting the monodisperse silica gel through vacuum filtration using a 0.45 μm filter membrane, repeatedly washing it with a mixture of ethanol and water at a volume ratio of 3:1, and drying it at a temperature of 40~60℃ for 2~3 hours.

[0058] In the above method, the reaction of the pre-synthesized ligand solution with silica microspheres to initiate silica polycondensation and organic component encapsulation is influenced by four factors: solid-solid ratio, solution concentration, preparation temperature, and reaction time.

[0059] In step 3 above, the unmodified mesoporous silica microspheres need to be ultrasonically dispersed in deionized water before the reaction to form a stable suspension. The concentration of the unmodified mesoporous silica microspheres is 4.5~5 g / L.

[0060] The above method uses ultrasound under normal temperature and pressure conditions.

[0061] In the method described in step 4 above, the solid-to-solid ratio, where the mass ratio of unmodified mesoporous silica microspheres to CTAB is 1:4~4.2.

[0062] The sodium hydroxide solution used in step 4 above is 2 mol / L.

[0063] In step 4 above, the solution concentration, the CTAB concentration can be 0.009~0.01 mol / L, the volume ratio of water:ethanol:sodium hydroxide solution is 52~55:15~20:1, and the concentration of sodium hydroxide solution is 2mol / L.

[0064] In step 4 above, the equilibration time of the mixed solution is 30-45 minutes.

[0065] In step 4 above, the mixing conditions are normal temperature and pressure.

[0066] In step 4 above, after the mixed solution is equilibrated, 0.14~0.16 volumes (compared to sodium hydroxide) of TEOS and 3~5 volumes (compared to sodium hydroxide) of the pre-synthesized ligand solution are injected.

[0067] In step 4 above, the reaction time is 6-7 hours and the rotation speed is 1000-1200 r / min.

[0068] In step 5 above, after the reaction, the product needs to be centrifuged and dispersed in deionized water, while a mineralization promoter, i.e., a ligand solution, is added.

[0069] In step 5 above, the concentration of the mineralization promoter is 0.1~0.2 mol / L, and the volume ratio of the pre-synthesized ligand solution to water is 1:5~6 mL.

[0070] In step 5 above, the reaction temperature can be a constant temperature water bath of 45~55℃.

[0071] In step 5 above, the reaction time is 10-12 hours.

[0072] The synthesized product, obtained by the method in step 5 above, is vacuum filtered through a 0.45 μm filter membrane, washed repeatedly with ethanol / water, and finally dried at 40~50℃ for 1~2 h.

[0073] In step 6 above, the mass-to-volume ratio of the mesoporous microsphere composite material to the solution is 1g:150~300mL; the acid solution for the uranyl ions is uranyl nitrate solution; and the adsorption conditions are stirring at 200~300 r / min for 6~8h.

[0074] Example 1

[0075] First, citric acid is pre-assembled into molecules via an ethylenediamine-mediated cross-linking reaction prior to the silica polycondensation reaction, with the aim of constructing covalent bridges between the organic molecules and the forming silica network.

[0076] (1) Dissolve 2.10 g of citric acid and 2.68 mL of ethylenediamine (EDA) together in 50 mL of deionized water and react for 30 min at 60 °C and 800 r / min with magnetic stirring.

[0077] (2) The homogeneous precursor solution was then transferred to a 100 mL polytetrafluoroethylene-lined hydrothermal reactor and hydrothermally reacted at 150 °C for 5 h under normal pressure. After the reaction was completed, the mixture was allowed to cool naturally to room temperature.

[0078] II. Synthesis of Unmodified Mesoporous Silica Microspheres (UMSS) via the Stuber Process with Precise Control

[0079] (3) Add 6 mL of tetraethyl orthosilicate (TEOS) to a ternary solvent system consisting of 74 mL of anhydrous ethanol, 10 mL of deionized water and 5 mL of ammonia, and hydrolyze by magnetic stirring at 500 r / min for 1 h.

[0080] (4) The monodisperse silica gel obtained was collected by vacuum filtration through a 0.45 μm filter membrane and repeatedly washed with ethanol / water (volume ratio 3:1) to remove residual reactants. The gel was then dried at 40~60℃ for 2 h to obtain unmodified mesoporous silica microspheres.

[0081] III. Mesoporous silica microspheres react with pre-synthesized ligand solution to initiate silica condensation and encapsulation of organic components;

[0082] (5) Disperse 50 mg of unmodified mesoporous silica microspheres in 10 mL of deionized water by ultrasonication to form a stable suspension;

[0083] (6) The suspension was added to a CTAB template system containing 200 mg cetyltrimethylammonium bromide (CTAB), 43 mL water, 15 mL ethanol and 0.8 mL 2 mol / L sodium hydroxide. After equilibration for 30 min, 0.125 mL tetraethyl orthosilicate was rapidly injected, followed by 3 mL of pre-synthesized ligand solution to initiate simultaneous silica polycondensation and organic component encapsulation.

[0084] (7) Stir vigorously at 1000~1200r / min for 6 h to ensure complete skeleton growth;

[0085] (8) Collect the product by centrifugation at 800-1000 rpm, redisperse it in 10 mL of deionized water (concentration), add 200 mg of sodium carbonate as a mineralization promoter and 2 mL of ligand solution, and stir at 50 °C for 10 h.

[0086] (9) Finally, the product was separated by vacuum filtration through a 0.45 μm filter membrane, washed three times with ethanol / water to remove the CTAB template agent, and dried to obtain the target product.

[0087] (10) The synthesized mesoporous silica composite material was dispersed in uranyl nitrate solutions with different pH values ​​and an initial uranium(VI) concentration of 400 mg / L. The pH of the system was precisely adjusted using 1.0 mol / L nitric acid / sodium hydroxide solution. The solid-liquid ratio of the adsorbent material to the uranyl nitrate solution was 1 g: 200 mL. The suspension was placed in a 25°C water bath and shaken at 200 r / min for 360 min. Finally, the solution was filtered to obtain a clear solution. The pH was adjusted to 1-5 before its adsorption capacity was measured. The adsorption capacity of the mesoporous silica composite material was 188.3 mg / g.

[0088] like Figure 2 The infrared characterization results shown demonstrate that the citric acid ligand was successfully loaded into the mesoporous silica microspheres.

[0089] Comparative Example 1

[0090] The difference between this comparative example and Example 1 is that the volume of the pre-synthesized ligand solution added in step (6) is changed, specifically:

[0091] (6) The suspension was added to a CTAB template system containing 200 mg cetyltrimethylammonium bromide (CTAB), 43 mL water, 15 mL ethanol and 0.8 mL 2 mol / L sodium hydroxide. After equilibration for 30 min, 0.125 mL tetraethyl orthosilicate was rapidly injected, followed by 8-10 mL of pre-synthesized ligand solution to initiate simultaneous silica polycondensation and organic component encapsulation.

[0092] The comparative example of mesoporous silica composite material has a concentration of 10~25 mg / g. The increase of ligand solution leads to pore blockage of the synthesized mesoporous silica microspheres, preventing uranyl ions from entering the pores and combining with the groups of the material, thus resulting in a reduction in adsorption capacity.

[0093] Comparative Example 2

[0094] The difference between this comparative example and Example 1 is that the stirring time in step (1) is changed, specifically:

[0095] (1) Dissolve 2.10 g of citric acid and 2.68 mL of ethylenediamine (EDA) together in 50 mL of deionized water and react for 10 min at 60 °C and 800 r / min with magnetic stirring.

[0096] In this comparative example, due to the short stirring time of citric acid, some citric acid was not completely dissolved, which affected the uniformity of the synthesized carbon source and thus reduced the adsorption capacity.

[0097] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for removing uranyl ions from solution using a mesoporous microsphere composite material, characterized in that, Includes the following steps: Step 1: Citric acid is pre-assembled via an ethylenediamine-mediated cross-linking reaction to obtain a pre-synthesized ligand solution; Step 2: Synthesize unmodified mesoporous silica microspheres using the Stuber process; Step 3: Disperse the unmodified mesoporous silica microspheres in deionized water by ultrasonication to form a stable suspension; Step 4: Add the suspension to the CTAB template system, and after equilibration for a period of time, add tetraethyl orthosilicate and the pre-synthesized ligand solution in sequence to carry out the reaction; Step 5: After the reaction is complete, the product is collected by centrifugation and dispersed in deionized water. A mineralization promoter and a pre-synthesized ligand solution are added, and the mixture is then filtered, washed, and dried to obtain a mesoporous microsphere composite material. Step 6: Place the mesoporous microsphere composite material into an acidic solution of uranyl ions to adsorb the uranyl ions.

2. The method for removing uranyl ions from solution using the mesoporous microsphere composite material according to claim 1, characterized in that, In step 1, the molecular pre-assembly of citric acid via an ethylenediamine-mediated cross-linking reaction specifically involves: Step 1.1: Dissolve citric acid and ethylenediamine in deionized water, mix thoroughly to obtain a homogeneous precursor solution; Step 1.2: The homogeneous precursor solution is transferred to a reaction vessel for hydrothermal reaction. After the reaction is completed, it is cooled to room temperature to obtain the pre-synthesized ligand solution.

3. The method for removing uranyl ions from solution using the mesoporous microsphere composite material according to claim 2, characterized in that, In step 1.1, the mass-to-volume ratio of citric acid to ethylenediamine is 1 g: 1~1.5 mL; the concentration of citric acid is 0.15~0.25 mol / L; the concentration of ethylenediamine is 0.5~1 mol / L; the mixing conditions are stirring at 800~850 r / min for 30~45 min at a temperature of 55~70℃; in step 1.2, the hydrothermal reaction temperature is 150~155℃ and the time is 5~6 h.

4. The method for removing uranyl ions from solution using the mesoporous microsphere composite material according to claim 1, characterized in that, In step 2, the synthesis of unmodified mesoporous silica microspheres specifically involves: Step 2.1: Add tetraethyl orthosilicate to a ternary solvent system for hydrolysis; Step 2.2: Unmodified mesoporous silica microspheres are obtained by filtration, washing, and drying.

5. The method for removing uranyl ions from solution using the mesoporous microsphere composite material according to claim 4, characterized in that, In step 2.1, the concentration of tetraethyl orthosilicate is 0.25~0.3 mol / L; the ternary solvent system is anhydrous ethanol, deionized water and ammonia water, with a volume ratio of 7.4:1:0.5; the hydrolysis time is 1~1.2h; in step 2.2, the drying temperature is 40~60℃ and the time is 2~3h.

6. The method for removing uranyl ions from solution using the mesoporous microsphere composite material according to claim 1, characterized in that, In step 3, the concentration of the unmodified mesoporous silica microspheres is 4.5~5 mg / mL.

7. The method for removing uranyl ions from solution using the mesoporous microsphere composite material according to claim 1, characterized in that, In step 4, the mass ratio of the CTAB template agent to the unmodified mesoporous silica microspheres is 4~4.2:1; the CTAB template system is a solution of hexadecyltrimethylammonium bromide, water, ethanol, and sodium hydroxide; the concentration of hexadecyltrimethylammonium bromide in the CTAB template system is 0.009~0.01 mol / L, and the volume ratio of water, ethanol, and sodium hydroxide solution is 52~55:15~20:

1.

8. The method for removing uranyl ions from solution using the mesoporous microsphere composite material according to claim 1, characterized in that, In step 4, the equilibration time is 30-45 min; after the mixed solution is equilibrated, the volume ratio of tetraethyl orthosilicate to sodium hydroxide solution is 0.14-0.16:1, and the ratio of ligand solution to sodium hydroxide solution is 3-5:1; after adding tetraethyl orthosilicate and the pre-synthesized ligand solution, the reaction is carried out at a stirring rate of 1000-1200 r / min for 6-7 h.

9. The method for removing uranyl ions from solution using the mesoporous microsphere composite material according to claim 1, characterized in that, In step 5, the centrifugation rate is 800~1000 r / min; the mass-volume ratio of the product to deionized water is 4.5~5 mg / mL; the mineralization promoter is sodium carbonate, and the concentration of the mineralization promoter is 0.1~0.2 mol / L; the volume ratio of the pre-synthesized ligand solution to deionized water is 1:5~6 mL; the reaction temperature is 45~55℃, and the time is 10~12 h.

10. The method for removing uranyl ions from solution using the mesoporous microsphere composite material according to claim 1, characterized in that, The mass-to-volume ratio of the mesoporous microsphere composite material to the solution is 1g:150~300mL; the acid solution of the uranyl ions is uranyl nitrate solution; the adsorption conditions are stirring at 200~300 r / min for 6~8h.

Images