Environmentally functional nanomaterial, preparation method thereof and application thereof in treatment of fluorine-rich radioactive nuclear wastewater

Abstract

The application discloses an environmental functional nanometer material, a preparation method thereof and application of the environmental functional nanometer material in treatment of fluorine-rich radioactive nuclear wastewater, and relates to the technical field of environmental functional nanometer materials. The application discloses an environmental functional nanometer material, a preparation method thereof and application of the environmental functional nanometer material in treatment of fluorine-rich radioactive nuclear wastewater, and relates to the technical field of environmental functional nanometer materials.

Description

Technical Field

[0001] This invention relates to the field of fluorine-rich radioactive nuclear wastewater treatment, and in particular to an environmentally functional nanomaterial, its preparation method, and its application in the treatment of fluorine-rich radioactive nuclear wastewater. Background Technology

[0002] Since Röntgen's discovery of X-rays in 1895 and Curie's discovery of radium in 1898, nuclear science and technology have been continuously developing and maturing, profoundly changing the world. However, while nuclear science has brought enormous benefits to humanity, it has also brought serious safety hazards. Among the three radioactive wastes—radioactive waste gas, wastewater, and solid waste—radioactive wastewater accounts for a considerable proportion, therefore, its treatment deserves particular attention.

[0003] Studies report that the discharge of nuclear wastewater has a devastating impact on marine ecosystems. When nuclear wastewater enters the ocean, it causes severe imbalances in the ecosystem. Fish and other marine life starve to death, posing a significant threat to key factors in maintaining marine ecological balance. Marine ecosystems are the guardians of the Earth's ecological balance, and the discharge of nuclear wastewater is destroying these guardians, leading to biodiversity loss and ecosystem collapse. Radioactive nuclides such as strontium, cobalt, and uranium will inevitably cause sustained and devastating damage to the entire marine ecosystem. The harm of nuclear wastewater mainly stems from the large amounts of 64 radioactive substances, including strontium, cobalt, and uranium, it contains. Furthermore, recent studies have found that radioactive nuclear wastewater is often rich in fluoride ions, which also pose a serious threat to the environment. Therefore, developing effective methods for treating fluoride-rich radioactive nuclear wastewater is urgently needed.

[0004] Currently, commonly used methods for treating fluoride-rich radioactive nuclear wastewater (mainly containing cobalt, strontium, and uranium nuclides) include adsorption, ion exchange, and chemical precipitation. Ion exchange resins exhibit poor selectivity for fluoride-rich radioactive nuclear wastewater, have low adsorption capacity, require frequent regeneration, and are costly. Chemical precipitation is a relatively easy and effective method for treating large volumes of wastewater, reducing the amount of final solid waste generated and facilitating subsequent solid waste treatment.

[0005] Studies have found that Ag and Cu can react with fluoride-rich radioactive wastewater to form insoluble compounds, thus removing the radioactive wastewater from the water. Monovalent copper ions are considered ideal adsorbents for removing radioactive wastewater due to their low toxicity and low cost. However, when using cuprous oxide, cuprous sulfide, and copper / divalent copper systems to remove radioactive ions from wastewater, problems such as high dosage, slow reaction kinetics, and low removal rates exist, particularly in response to sudden nuclear leaks, presenting urgent technical challenges. Therefore, if cuprous chloride precipitation is used to remove fluoride-rich radioactive wastewater, improvements are needed, such as adding membrane separation units or other advanced treatment facilities or processes to improve the removal efficiency, increasing the complexity and cost of fluoride-rich radioactive wastewater treatment. Therefore, new technologies are urgently needed to remove radionuclides and fluoride ions from fluoride-rich radioactive wastewater.

[0006] Adsorption methods, characterized by their simplicity, large adsorption capacity, high selectivity, and strong trace treatment capabilities, have become the most competitive approach. Commonly used adsorbents include zeolite and activated carbon, but their removal efficiency for radioactive nuclear wastewater is unsatisfactory. While impregnation and modification with silver and copper salts have improved the removal rate, the modification costs are high, and leakage of the impregnating agent is a common concern, limiting their practical application. Therefore, it is necessary to develop adsorbents that are simple to prepare, low in cost, and highly effective at removing fluoride-rich radioactive nuclear wastewater. Summary of the Invention

[0007] Based on the technical problems existing in the background technology, this invention proposes an environmental functional nanomaterial, its preparation method and application.

[0008] The present invention proposes a method for preparing environmentally functional nanomaterials, comprising the following steps:

[0009] S1. Mix the hydrated quartz powder and the natural copper-silver ore powder evenly to obtain the mixture;

[0010] S2. Add an appropriate amount of solvent to the mixture and stir until uniform. After drying, calcine at high temperature under a reducing atmosphere and then cool under an inert atmosphere to obtain the final product.

[0011] Preferably, the mass ratio of the diatomite powder to the natural copper-silver ore powder is (1-4):(1-5).

[0012] In this invention, the diatomite powder and the natural copper-silver ore powder are obtained by crushing and screening diatomite and natural copper-silver ore, respectively, as raw materials.

[0013] Preferably, the natural copper-silver ore contains 20-50 wt% silver and 5-20 wt% copper.

[0014] Preferably, in S2, the particle size of the diatomite powder is 0.0075-0.1 mm, and the particle size of the copper-silver ore powder is 0.0075-0.1 mm.

[0015] In this invention, the copper-silver ore is a natural copper-silver ore.

[0016] In S2, the mass of the solvent is 10-30% of the mass of the mixture; the solvent is water, ethanol, or a combination thereof.

[0017] Preferably, in S2, the high-temperature calcination temperature is 400–1000°C, and the time is 2–5 hours.

[0018] In this invention, the reducing atmosphere refers to a hydrogen atmosphere or a mixed atmosphere of hydrogen and an inert gas, wherein hydrogen accounts for more than 5% of the total volume in the mixed atmosphere of hydrogen and inert gas, and the inert gas refers to a non-reactive gas, specifically at least one of nitrogen, helium, neon, and argon.

[0019] In this invention, an inert atmosphere refers to a non-reactive gas atmosphere, specifically a nitrogen atmosphere, a helium atmosphere, a neon atmosphere, an argon atmosphere, or a mixture of two or more of the above gases.

[0020] This invention also proposes an environmentally functional nanomaterial, which is prepared by the aforementioned method.

[0021] This invention also proposes the application of the aforementioned environmentally functional nanomaterials in the treatment of fluoride-rich radioactive nuclear wastewater.

[0022] Preferably, the radioactive nuclear ions in the fluorine-rich radioactive wastewater include at least one of cobalt, strontium, and uranium.

[0023] The present invention also proposes a method for treating fluoride-rich radioactive nuclear wastewater, comprising: adding the aforementioned environmentally functional nanomaterials to the fluoride-rich radioactive nuclear wastewater, controlling the pH to 7, and removing fluoride ions and radioactive nuclear ions in an aeration reactor under conditions of oscillation and continuous aeration.

[0024] This method, by continuously aerating fluoride-rich radioactive nuclear wastewater with the added environmentally functional nanomaterials, can accelerate the rapid adsorption of fluoride-rich radioactive nuclear wastewater. It can serve as an emergency measure for quickly responding to fluoride-rich radioactive nuclear wastewater pollution.

[0025] Preferably, in the process of treating fluoride-rich radioactive nuclear wastewater using the aforementioned environmental functional nanomaterials, the pH is controlled at 4–10; more preferably, the pH is controlled at 4–8.

[0026] The beneficial effects of this invention are as follows:

[0027] Boehmite is an amorphous aluminosilicate mineral composed of silicon dioxide, water, and aluminum oxide, belonging to the category of non-traditional nano-mineral resources. It is mainly composed of various mineral nanoparticles or nano-minerals, containing non-nano-mineral particles. Previous studies have found that boehmite exhibits a sponge-like aggregate structure in its microstructure, possessing a large surface area, high chemical reactivity, and abundant fine pores. Boehmite is a major clay mineral in volcanic ash soils, formed during weathering in low-temperature, low-pressure environments, exhibiting aggregate morphologies, commonly appearing as stalactite-like, nipple-like, and grape-like massive structures. Boehmite effectively adsorbs different anions and cations from water. With a high degree of hydration and variable potential, it can form stable mineral-organic complexes through anion and ligand exchange reactions, providing physical protection for organic matter. Boehmite is abundant, environmentally friendly, and inexpensive. It possesses a natural multi-level porous structure, a large specific surface area, high chemical reactivity, ion exchange capacity, high thermal decomposition activity, and high adsorption capacity, making it believed to effectively inhibit the migration of radioactive nuclides such as fluorine, cobalt, strontium, and uranium. The interfacial reactions of low-order gibbsite with fluorine, cobalt, strontium, and uranium can effectively retain their migration. More importantly, gibbsite exhibits a high affinity for fluorine, cobalt, strontium, and uranium ions.

[0028] Natural copper-silver deposits generally contain high levels of copper, making them important associated metallic minerals and a significant nano-mineral resource.

[0029] This invention utilizes diatomite and natural copper-silver ore as raw materials, and obtains environmentally functional nanomaterials with a main phase composition of amorphous diatomite and nano-zero-valent copper-silver composite materials through pyrolysis and reduction reactions under a reducing atmosphere. High-temperature calcination of diatomite under a reducing atmosphere results in a large amount of chemical water (structural water, crystal water, interlayer water, adsorbed water, and zeolite water) in its crystal structure. High-temperature calcination and dehydration further nanostructurize the diatomite, resulting in an amorphous structure and increased specific surface area of ​​the pyrolysis products. Calcination under a reducing atmosphere also reduces the negative charge on the surface of diatomite, increases the isoelectric point of the nanomaterials, and further enhances electrostatic adsorption. High-temperature calcination of copper-silver ore also forms nanostructured porous zero-valent copper-silver composite materials, preventing the aggregation of nano-zero-valent copper-silver and increasing the active sites of the nanomaterials. Simultaneously, calcination of diatomite allows metal cations within the pores of the composite minerals to escape, synergistically removing fluoride-rich radioactive wastewater and improving the purification effect of the nanomaterials on fluoride-rich radioactive wastewater.

[0030] This invention utilizes diaspore and natural copper-silver ore as raw materials to prepare environmentally functional nanomaterials. The raw materials are inexpensive, and the preparation method is simple. The resulting environmentally functional nanomaterials possess high porosity, high adsorption capacity, and high biochemical activity. They exhibit strong adsorption of fluoride ions and radioactive nuclear ions in fluoride-rich radioactive nuclear wastewater, demonstrating excellent removal efficiency. The mechanism by which these nanomaterials remove fluoride-rich radioactive nuclear wastewater includes electrostatic adsorption, ligand exchange, Lewis acid-base theory, and co-precipitation, achieving highly efficient removal of fluoride-rich radioactive nuclear wastewater. Attached Figure Description

[0031] Figure 1 XRD patterns of natural copper- and silver-rich minerals and environmentally functional nanomaterials;

[0032] Figure 2 SEM image of diatomite;

[0033] Figure 3 SEM image of a natural copper-silver rich deposit;

[0034] Figure 4 SEM image of the environmentally functional nanomaterials prepared in Example 3;

[0035] Figure 5 SEM image of the environmentally functional nanomaterials prepared in Example 7;

[0036] Figure 6 Images of diaspore, natural copper-silver ore, and environmentally functional nanomaterials.

[0037] Figure 7 The figures show the removal effects of fluoride-rich radioactive nuclear wastewater on Examples 1-7 and Comparative Examples 1-6 at different adsorption reaction times.

[0038] Figure 8 The diagram shows the aeration reactor used in Examples 1-7 and Comparative Examples 1-6 to remove fluoride-rich radioactive nuclear wastewater under emergency conditions.

[0039] Figure 9 The removal effect of fluoride-rich radioactive nuclear wastewater by Examples 1-7 and Comparative Examples 1-6 under different adsorption reaction times with the assistance of aeration is shown in the figure.

[0040] Figure 10 This is a schematic diagram illustrating the preparation of environmentally functional nanomaterials. Detailed Implementation

[0041] The technical solution of the present invention will now be described in detail through specific embodiments.

[0042] Example 1:

[0043] A method for preparing environmentally functional nanomaterials includes the following steps:

[0044] S1. Crush diatomite to obtain diatomite powder; crush natural copper-silver ore (containing 40wt% silver and 7.5wt% copper) to obtain natural copper-silver ore powder; mix the diatomite powder and the natural copper-silver ore powder evenly to obtain a mixture, wherein the mass ratio of diatomite powder to natural copper-silver ore powder is 2:1, the particle size of the diatomite powder is 0.0075-0.1mm, and the particle size of the natural copper-silver ore powder is 0.0075-0.1mm.

[0045] S2. Add water equivalent to 25% of the mass of the mixture to the mixture and stir evenly. After drying, calcine at 600°C for 2 hours under a hydrogen atmosphere with a heating rate of 5°C per minute. Then cool under a nitrogen atmosphere to obtain the final product.

[0046] The specific surface area of ​​the environmentally functional nanomaterials prepared above is 83 m². 2 / g, Zeta potential is 7.4;

[0047] Example 2:

[0048] A method for preparing environmentally functional nanomaterials includes the following steps:

[0049] S1. Crush diatomite to obtain diatomite powder; crush natural copper-silver ore (containing 40wt% silver and 7.5wt% copper) to obtain natural copper-silver ore powder; mix the diatomite powder and the natural copper-silver ore powder evenly to obtain a mixture, wherein the mass ratio of diatomite powder to natural copper-silver ore powder is 1:1, the particle size of the diatomite powder is 0.0075-0.1mm, and the particle size of the natural copper-silver ore powder is 0.0075-0.1mm;

[0050] S2. Add water equivalent to 25% of the mass of the mixture to the mixture and stir evenly. After drying, calcine at 700°C for 3 hours in a hydrogen atmosphere with a heating rate of 10°C per minute, and then cool in a nitrogen atmosphere to obtain the final product.

[0051] The specific surface area of ​​the environmentally functional nanomaterials prepared above is 76 m². 2 / g, Zeta potential is 8.1;

[0052] Example 3:

[0053] A method for preparing environmentally functional nanomaterials includes the following steps:

[0054] S1. Crush diatomite to obtain diatomite powder; crush natural copper-silver ore (containing 40wt% silver and 7.5wt% copper) to obtain natural copper-silver ore powder; mix the diatomite powder and the natural copper-silver ore powder evenly to obtain a mixture, wherein the mass ratio of diatomite powder to natural copper-silver ore powder is 1:2, the particle size of the diatomite powder is 0.0075-0.1mm, and the particle size of the natural copper-silver ore powder is 0.0075-0.1mm;

[0055] S2. Add water equivalent to 25% of the mass of the mixture to the mixture and stir evenly. After drying, calcine at 800°C for 4 hours in a hydrogen atmosphere with a heating rate of 7°C per minute. Then cool in a nitrogen atmosphere to obtain the final product.

[0056] The specific surface area of ​​the environmentally functional nanomaterials prepared above is 90 m². 2 / g, Zeta potential is 6.8;

[0057] Example 4:

[0058] A method for preparing environmentally functional nanomaterials includes the following steps:

[0059] S1. Crush diatomite to obtain diatomite powder; crush natural copper-silver ore (containing 40wt% silver and 7.5wt% copper) to obtain natural copper-silver ore powder; mix the diatomite powder and the natural copper-silver ore powder evenly to obtain a mixture, wherein the mass ratio of diatomite powder to natural copper-silver ore powder is 1:3, the particle size of the diatomite powder is 0.0075-0.1mm, and the particle size of the natural copper-silver ore powder is 0.0075-0.1mm;

[0060] S2. Add water equivalent to 25% of the mass of the mixture to the mixture and stir evenly. After drying, calcine at 900°C for 3 hours in a hydrogen atmosphere with a heating rate of 8°C per minute. Then cool in a nitrogen atmosphere to obtain the final product.

[0061] The specific surface area of ​​the environmentally functional nanomaterials prepared above is 67 m². 2 / g, Zeta potential is 8.5;

[0062] Example 5:

[0063] A method for preparing environmentally functional nanomaterials includes the following steps:

[0064] S1. Crush diatomite to obtain diatomite powder; crush natural copper-silver ore (containing 40wt% silver and 7.5wt% copper) to obtain natural copper-silver ore powder; mix the diatomite powder and the natural copper-silver ore powder evenly to obtain a mixture, wherein the mass ratio of diatomite powder to natural copper-silver ore powder is 4:1, the particle size of the diatomite powder is 0.0075-0.1mm, and the particle size of the natural copper-silver ore powder is 0.0075-0.1mm.

[0065] S2. Add water equivalent to 30% of the mass of the mixture to the mixture and stir evenly. After drying, calcine at 700°C for 1 hour in a hydrogen atmosphere with a heating rate of 10°C per minute. Then cool in a nitrogen atmosphere to obtain the final product.

[0066] The specific surface area of ​​the environmentally functional nanomaterials prepared above is 85 m². 2 / g, Zeta potential is 9.3;

[0067] Example 6:

[0068] A method for preparing environmentally functional nanomaterials includes the following steps:

[0069] S1. Crush diatomite to obtain diatomite powder; crush natural copper-silver ore (containing 40wt% silver and 7.5wt% copper) to obtain natural copper-silver ore powder; mix the diatomite powder and the natural copper-silver ore powder evenly to obtain a mixture, wherein the mass ratio of diatomite powder to natural copper-silver ore powder is 5:2, the particle size of the diatomite powder is 0.0075-0.1mm, and the particle size of the natural copper-silver ore powder is 0.0075-0.1mm;

[0070] S2. Add water equivalent to 15% of the mass of the mixture to the mixture and stir evenly. After drying, calcine at 800°C for 2 hours under a hydrogen atmosphere with a heating rate of 6°C per minute. Then cool under a nitrogen atmosphere to obtain the final product.

[0071] The specific surface area of ​​the environmentally functional nanomaterials prepared above is 97 m². 2 / g, Zeta potential is 6.1;

[0072] Example 7:

[0073] A method for preparing environmentally functional nanomaterials includes the following steps:

[0074] S1. Crush diatomite to obtain diatomite powder; crush natural copper-silver ore (containing 40wt% silver and 7.5wt% copper) to obtain natural copper-silver ore powder; mix the diatomite powder and the natural copper-silver ore powder evenly to obtain a mixture, wherein the mass ratio of diatomite powder to natural copper-silver ore powder is 7:3, the particle size of the diatomite powder is 0.0075-0.1mm, and the particle size of the natural copper-silver ore powder is 0.0075-0.1mm;

[0075] S2. Add water equivalent to 10% of the mass of the mixture to the mixture and stir evenly. After drying, calcine at 1000°C for 3 hours in a hydrogen atmosphere with a heating rate of 4°C per minute. Then cool in a nitrogen atmosphere to obtain the final product.

[0076] The specific surface area of ​​the environmentally functional nanomaterials prepared above is 83 m². 2 / g, Zeta potential is 7.7;

[0077] Comparative Example 1:

[0078] Boehmite was crushed to obtain boehmite powder with a particle size of 0.0075–0.1 mm. The boehmite powder was first calcined at 800°C for 4 hours under a hydrogen atmosphere with a heating rate of 10°C per minute, and then cooled under a nitrogen atmosphere to obtain porous boehmite material. Boehmite itself possesses a nanostructure, which is further nanostructured after high-temperature calcination, resulting in a specific surface area of ​​79 m². 2 / g, Zeta potential is 5.8;

[0079] Comparative Example 2:

[0080] Natural copper-silver ore (containing 40 wt% silver and 7.5 wt% copper) was crushed to obtain natural copper-silver ore powder with a particle size of 0.0075–0.1 mm. The powder was then calcined at 800°C for 4 hours under a hydrogen atmosphere with a heating rate of 10°C per minute, followed by cooling under a nitrogen atmosphere to obtain a nano-zero-valent copper-silver composite material with a specific surface area of ​​18 m². 2 / g, Zeta potential is 5.4;

[0081] Comparative Example 3:

[0082] Nano-sized zero-valent silver composites were prepared by liquid-phase reduction of silver salts with sodium borohydride. These nano-sized zero-valent silver composites exhibited agglomeration, low active sites, and a specific surface area of ​​7 m². 2 / g;

[0083] Comparative Example 4:

[0084] Copper salts were used to prepare nano-zero-valent copper composite materials under the liquid-phase reduction of sodium borohydride. These nano-zero-valent copper composite materials exhibited agglomeration, low active sites, and a specific surface area of ​​5 m² / g. 2 / g;

[0085] Comparative Example 5:

[0086] Commercially available nano silver powder has a specific surface area of ​​8m². 2 / g;

[0087] Comparative Example 6:

[0088] Commercially available nano copper powder has a specific surface area of ​​5m². 2 / g;

[0089] Test case

[0090] Based on the similarity of isotopic element ions, this invention selects cobalt-59 instead of cobalt-60, cobalt-58, and cobalt-57; strontium-88 instead of strontium-90; and uranium-235, uranium-238, and uranium-234 to conduct adsorption experiments, thereby reducing harm to experimental personnel and the environment.

[0091] Characterization tests:

[0092] Figure 1 -A is the XRD pattern of natural copper-silver rich minerals. The figure shows the presence of characteristic diffraction peaks of copper and silver, as well as characteristic diffraction peaks of quartz, indicating that natural copper-silver rich minerals have high crystallinity. Figure 1 -B is the XRD pattern of the environmental functional nanomaterial. As can be seen from the figure, the environmental functional nanomaterial has an amorphous structure. This is because the high-temperature hydrogen reduction calcination composite material has an amorphous structure, which has high activity.

[0093] Figure 2 The microstructure morphology of diatomite at different magnifications. Figure 2 As can be seen from AD, hydrated alumina has kidney-shaped, granular, and plate-like structural morphologies. EH further shows that hydrated alumina has a nanoporous structure, which further indicates that hydrated alumina is suitable as a carrier to improve the activity of adsorbents.

[0094] Figure 3 The microstructure morphology of natural copper-silver rich deposits at different magnifications is shown by... Figure 3 In the AC section, it can be seen that the natural copper-silver ore has nano-sized particles and a layered stacked structure. In the D section, at high magnification, a nanoporous structure can be observed.

[0095] Figure 4 To illustrate the microstructure morphology of environmental functional nanomaterials at different magnifications, by Figure 4The AD analysis reveals that the environmentally functional nanomaterials have a nanoporous structure, with a large number of nanoparticles loaded on a plate-like structure, exhibiting high activity.

[0096] Figure 5 To illustrate the microstructure morphology of environmental functional nanomaterials at different magnifications, by Figure 5 As can be seen from the AD analysis, environmental functional nanomaterials possess a nanoporous structure, an open pore structure, and high activity.

[0097] Figure 6 In the image: AB represents a physical image of diaspore; CD represents a physical image of a natural copper- and silver-rich mineral; EF represents a physical image of an environmentally functional nanomaterial.

[0098] Adsorption experiment:

[0099] Accurately weigh 0.1 g of the samples from Examples 1-7 and Comparative Examples 1-6 above, and add them to 100 mL of a fluoride-rich radioactive ion concentration of 30 mmol / L (the concentrations of fluoride, cobalt, strontium, and uranium ions in the aqueous solution are each 30 mmol / L). The pH value is 7, and the solution is shaken at 25°C for 3 h. The concentrations of fluoride ions and radioactive ions in the supernatant are measured using ion chromatography and inductively coupled plasma mass spectrometry (ICP-MS), and the removal rates of fluoride ions and radioactive ions are calculated. The test results are shown in […]. Figure 7 See Table 1.

[0100] Table 1. Statistical Table of Removal Rate of Fluorine-Rich Radioactive Nuclear Wastewater by Environmental Functional Nanomaterials

[0101]

[0102] Depend on Figure 7 As shown in Table 1, Examples 1-7 exhibit high removal efficiency for fluoride-rich radioactive nuclear wastewater, superior to Comparative Examples 1-6. This is because the environmentally functional nanomaterials obtained by reducing and roasting natural copper- and silver-rich minerals in a hydrogen atmosphere using hydrated alumina composites contain active components such as hydrated alumina, nano-zero-valent copper, and nano-zero-valent silver, possessing a large specific surface area, high activity, and high Zeta potential. Nano-zero-valent copper and nano-zero-valent silver exhibit strong reactivity and act as electron donors, transferring electrons to fluoride ions, cobalt ions, strontium ions, and uranium ions, thereby achieving the reduction of fluoride ions and radioactive ions.

[0103] The environmentally functional nanomaterials prepared in this invention exhibit both redox effects and coprecipitation when treating fluoride, cobalt, strontium, and uranium ions in the environment. During the hydrolysis of nano-zero-valent copper and nano-zero-valent silver, they react with cobalt, fluoride, strontium, and uranium ions, as well as OH- ions in the solution. -Coordination reactions occur, producing complexes with low solubility for fluorine, cobalt, strontium, and uranium.

[0104] The environmentally functional nanomaterials of this invention exhibit co-precipitation during the adsorption of fluoride ions, generating CuF2(K) ions. sp =8.3×10 -17 Surface precipitation of fluorine-rich radioactive nuclear wastewater. The environmental functional nanomaterials prepared in this invention have high specific surface energy and strong adsorption capacity. They can rapidly and efficiently adsorb fluorine-rich radioactive nuclear wastewater into the environmental functional nanomaterials, which in Cu 0 -H2O and Ag 0 The following reactions occur with water in the H2O system ((1)-(6)):

[0105] Cu 0 +2H₂O → Cu 2+ +H2+2OH - (1)

[0106] 2Cu 2+ +2H₂O → 2Cu 3+ +H2+2OH - (2)

[0107] Ag 0 +2H₂O → Ag 2+ +H2+2OH - (3)

[0108] 2Ag 2+ +2H₂O → 2Ag 3+ +H2+2OH - (4)

[0109] 2Cu 2+ +2F - →2CuF2 (6)

[0110] Aeration-assisted adsorption test:

[0111] Accurately weigh 0.1g of the samples from Examples 1-7 and Comparative Examples 1-6 above, and add them respectively to an aeration reactor containing 100mL of an aqueous solution with a fluorine-rich radioactive ion concentration of 30mmol / L (the aqueous solution contains fluoride ions, cobalt ions, strontium ions, and uranium ions, each at a concentration of 30mmol / L). (The aeration reactor is as follows:) Figure 8 (As shown in the figure), the pH value was 7, and it was shaken at 25℃ for 3 hours with an aeration rate of 10 mL / L, and aeration was carried out continuously. The concentration of radioactive ions in the supernatant was determined by ion chromatography and inductively coupled plasma mass spectrometry (ICP-MS), and the removal rates of fluoride ions and radioactive ions were calculated. The results are shown in Table 2 and 3. Figure 9 As shown.

[0112] Table 2. Statistical Table of Removal Rate of Fluorine-Rich Radioactive Nuclear Wastewater by Aeration-Assisted Environmental Functional Nanomaterials

[0113]

[0114]

[0115] Experimental results show that the removal rates of fluorine-rich radioactive ions in Examples 1-7 and Comparative Examples 1-6 are shown in Table 2 and Table 2, respectively. Figure 9 As shown, the environmental functional nanomaterials of this invention exhibit excellent adsorption capacity for radioactive ions with the assistance of aeration, significantly improving the removal rate of fluoride-rich radioactive ions. The aqueous solutions of the aforementioned radioactive ions treated with the environmental functional nanomaterials of Examples 1-7 show superior removal effects on fluoride-rich radioactive ions compared to Comparative Examples 1-6. Their high adsorption rate and high adsorption capacity for fluoride-rich radioactive ions are due to the fact that aeration accelerates the oxidation rate of the environmental functional nanomaterials (nano-zero-valent copper and nano-zero-valent silver), efficiently promoting the complexation of copper and silver with fluoride-rich radionuclides. This is an effective emergency method for addressing wastewater pollution caused by fluoride-rich radioactive ions.

[0116] Synthesis Mechanism Analysis:

[0117] Depend on Figure 10 It can be seen that gibbsite has tube walls composed of curled gibbsite flakes, with its internal aluminum hydroxyl groups replaced by orthosilicate groups, making it an amorphous mineral with single-walled nanospheres. The nanostructured spheres are also composed of curled gibbsite flakes, with their internal oligomers or aluminum hydroxyl groups replaced by orthosilicate groups. The outer diameter of a single nanoparticle is approximately 3-6 nm, and the nanostructured sphere walls are distributed with nanostructured pores of approximately 0.4 nm in diameter. When natural copper- and silver-rich minerals are combined with gibbsite and calcined under a hydrogen atmosphere, nano-zero-valent copper and nano-zero-valent silver particles can be formed on the surface of the gibbsite, effectively increasing the active sites.

[0118] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing environmentally functional nanomaterials, characterized in that, Includes the following steps: S1. Mix the diatomite powder and the natural copper-silver ore powder evenly to obtain a mixture. The natural copper-silver ore contains 20-50 wt% silver and 5-20 wt% copper. The mass ratio of the diatomite powder to the natural copper-silver ore powder is (1-4):(1-5). S2. Add an appropriate amount of solvent to the mixture and stir until uniform. After drying, calcine at high temperature under a reducing atmosphere and then cool under an inert atmosphere to obtain the final product.

2. The method for preparing environmentally functional nanomaterials according to claim 1, characterized in that, The particle size of the diaspore powder is 0.0075~0.1mm, and the particle size of the natural copper-silver ore powder is 0.0075~0.1mm.

3. The method for preparing nanomaterials according to claim 1, characterized in that, In S2, the mass of the solvent is 10-30% of the mass of the mixture; the solvent is water, ethanol, or a combination thereof.

4. The method for preparing environmentally functional nanomaterials according to claim 1, characterized in that, In S2, the high-temperature calcination temperature is 400~1000℃ and the time is 2~5 h.

5. An environmentally functional nanomaterial, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 4.

6. The application of the environmentally functional nanomaterials of claim 5 in the treatment of fluorine-rich radioactive nuclear wastewater.

7. The application according to claim 6, characterized in that, The radioactive nuclear ions in the fluorine-rich radioactive wastewater include at least one of cobalt, strontium, and uranium.

8. A method for treating fluoride-rich radioactive nuclear wastewater, characterized in that, The environmental functional nanomaterials of claim 5 are added to the fluoride-rich radioactive nuclear wastewater, and fluoride ions and radioactive nuclear ions are removed in the aeration reactor under conditions of oscillation and continuous aeration.

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