Application of a colloidal material for adsorbing metal elements in the groundwater environment

Abstract

The present invention provides an application of a colloidal material for adsorbing metal elements in a groundwater environment, belonging to the fields of environmental protection and water treatment. The colloidal material is illite colloid, and the illite colloid is used for adsorbing the metal elements europium or americium. In the present invention, the initial concentration of europium or americium in water is above 0.3 mg / L, the dosage of the illite colloid is 0.5 - 2 g / L, the contact time of the illite colloid with the water containing europium or americium is above 10 min, and the adsorption reaction temperature is above 20 °C. The illite colloid provided by the present invention can be effectively used for adsorbing europium and americium in water treatment.

Description

Technical Field

[0001] The present invention relates to the fields of environmental protection and water treatment, and particularly to an application of a colloidal material for adsorbing metal elements in a groundwater environment. Background Art

[0002] The decay period of radioactive waste is as long as tens of thousands or even hundreds of thousands of years. Therefore, the operation period designed for a deep geological disposal repository also needs to meet the requirement of tens of thousands of years. Since the geological disposal repository is placed in the deep underground granite layer, it will be eroded by groundwater in the rock and soil fissures all year round, and a relevant stable colloidal material will be formed in the buffer material barrier. When the high-level radioactive waste geological disposal repository is invaded by groundwater, the long-lived radionuclides in the waste solidified body will leach out from the solidified body along with the erosion of groundwater. Once the waste packaging container is corroded and damaged, the radionuclides will further interact with the surrounding buffer backfill materials, etc. with the migration of groundwater to form radioactive colloids. Moreover, the colloids dispersed in water have good migration ability, which can accelerate the movement of originally less mobile components through the mobile colloids, resulting in changes in the fate of radioactive pollutants and thus posing a potential threat to environmental safety. Considering the leakage risk of the disposal repository, a large number of studies have been carried out on the colloids generated around it, especially on bentonite colloids, which have a large specific surface area and high surface energy and have a strong adsorption capacity for radionuclides.

[0003] As a trivalent rare earth element, Eu(III) is usually used as a simulated nuclide of extremely radioactive and toxic Am(III) in experiments because the ionic radius and physicochemical properties of Eu(III) are close to those of trivalent actinides when studying radionuclides.

[0004] In the prior art, there have been many studies on bentonite colloids, but few studies on other colloids. Therefore, there is a need in the art to develop a new colloidal material for water treatment and its preparation method, and the application of this new colloidal material for adsorbing metal elements in a groundwater environment is also worthy of research and development. Summary of the Invention

[0005] Therefore, the present invention first provides an application of a colloidal material for adsorbing metal elements in a groundwater environment. The colloidal material is illite colloid, and the illite colloid is used to adsorb the metal elements europium or americium. The dosage of the illite colloid is 0.5 - 2 g / L. The contact time between the illite colloid and the water containing europium or americium is more than 10 min. The initial concentration of europium or americium in the water is more than 0.3 mg / L. The adsorption reaction temperature of the illite colloid and the water containing europium or americium is more than 20 °C. The preparation method of the illite colloid includes first mixing illite powder with ultrapure water or deionized water, ultrasonic oscillation and then standing for a period of time, taking the supernatant into a centrifuge tube for centrifugation, taking the centrifuged supernatant and standing it in a first container, taking the supernatant of the first container into a second container for standing, and then taking the supernatant of the second container into a third container to obtain the illite colloid. And the weight ratio of the illite powder to the ultrapure water or deionized water is 1:50 - 200. The time of the ultrasonic oscillation is 10 minutes to 10 hours. And the standing time after ultrasonic oscillation is more than 12 hours. The centrifugation speed is more than 4000 rpm, and the centrifugation time is more than 10 min. The standing time of the supernatant in the first container is more than 24 hours, and the standing time of the supernatant in the second container is more than 24 hours. The illite colloid is stored in a refrigerator at 2 - 8 °C for standby, and the pH value of the illite colloid is adjusted to 9 - 12 before storage.

[0006] In a specific embodiment, the initial concentration of europium or americium in the water is 1.6 - 4.8 mg / L.

[0007] In a specific embodiment, the contact time between the illite colloid and the water containing europium or americium is 15 - 60 minutes, and the adsorption reaction temperature of the illite colloid and the water containing europium or americium is more than 40 °C.

[0008] In a specific embodiment, the pH value of the water containing europium or americium is 8 or more.

[0009] In a specific embodiment, the pH value of the water containing europium or americium is less than 8, and an alkali or fulvic acid is added to the water containing europium or americium for pretreatment.

[0010] In a specific embodiment, in the preparation method, the weight ratio of the illite powder to the ultrapure water or deionized water is 1:80 - 150; the time of the ultrasonic oscillation is 0.5 - 3 hours; and the standing time after ultrasonic oscillation is more than 24 hours; the centrifugation speed is 7000 - 10000 rpm; the centrifugation time is more than 30 min; the first container is a plastic container or a glass container, and the second container is a plastic container or a glass container.

[0011] The present invention also provides a method for preparing a colloidal material for water treatment. The colloidal material is illite colloid, and the preparation method includes first mixing illite powder with ultrapure water or deionized water, ultrasonic oscillation followed by standing for a period of time, taking the supernatant into a centrifuge tube for centrifugation, taking the centrifuged supernatant and standing it in a first container, taking the supernatant of the first container into a second container for standing, and then taking the supernatant of the second container into a third container to obtain the illite colloid.

[0012] In the present invention, according to the experimental experience of the inventors, generally when pouring the supernatant of the second container into the third container, illite colloid can already be formed.

[0013] In the present invention, the first container and the second container are transparent plastic containers or glass containers, which are convenient for observing the effect of static sedimentation; the material of the third container is not limited, and it can be a plastic container, a glass container, or other containers such as a ceramic container. The third container can also be the first container after being washed.

[0014] In the present invention, if the prepared illite colloid is not used immediately, it needs to be stored refrigerated in a refrigerator at 2 - 8 °C. Otherwise, if the temperature is too high for a long time, the illite colloid is likely to return to the clear liquid state.

[0015] In the present invention, an alkaline environment is more suitable for storing illite colloid. In the present invention, for example, 0.1 mol / L of NaOH or HCl is used to adjust the pH value of the illite colloid.

[0016] The present invention also provides a colloidal material prepared by the above - described preparation method.

[0017] The beneficial effects of the present invention at least include: the illite colloid provided by the present invention can be effectively used to adsorb europium and americium in water treatment. The preparation method of the illite colloid in the present invention is simple and effective, and the prepared illite colloid has good adsorption performance for europium and americium. By simulating the adsorption performance of illite colloid for Eu(III) in different water chemical environments and exploring its adsorption mechanism, the conclusion is that illite colloid can be an effective carrier for the migration of Eu(III) in the water environment, providing a basic basis for exploring the leakage of the radionuclide americium around the deep geological disposal repository. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1The particle size distribution of the illite colloid of the present invention within 30 days.

[0020] Figure 2 The change diagram of the Zeta potential of the illite colloid of the present invention within 30 days and at different pH values.

[0021] Figure 3 The SEM images of the illite colloid of the present invention before and after adsorbing Eu(III).

[0022] Figure 4 The influence of contact time on the adsorption of Eu(III) on the illite colloid.

[0023] Figure 5 The fitting curve diagram of the pseudo-second-order adsorption kinetic model.

[0024] Figure 6 The adsorption capacity curve diagram of the illite colloid under different temperatures and initial concentrations of Eu(III).

[0025] Figure 7 The influence of temperature on the distribution coefficient of Eu(III) adsorption on the illite colloid under different solution concentrations.

[0026] Figure 8 The Langmuir model diagram.

[0027] Figure 9 The Freundlich model diagram.

[0028] Figure 10 The adsorption rate diagram of the illite colloid of the present invention at different pH values.

[0029] Figure 11 The influence of fulvic acid on the adsorption of Eu(III) on the illite colloid.

[0030] Figure 12 The influence of ionic strength on adsorption. Detailed implementation manners

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0032] Illite is a potassium-rich silicate mica clay mineral, named after its earliest discovery on Ellis Island in the United States. Illite is a common clay mineral, often weathered from muscovite and potassium feldspar, and is produced in argillaceous rocks or formed by the alteration of other minerals. Illite is a new mineral species in China. Illite ore was initially discovered in Duchuantou Village, Shuangchao Township, Lucheng District, Wenzhou City, Zhejiang Province. The illite resources in Antu County, Jilin Province are very rich, with proven reserves of more than 140 million tons and a prospective reserve of more than 200 million tons, belonging to a single super-large sandy illite deposit. Illite has excellent chemical and physical properties such as rich potassium, high aluminum, low iron, smoothness, brightness, fineness, and heat resistance. Illite can freely release negative ions and far-infrared rays. Illite has a wide range of uses. In the ceramic industry, illite is used as a raw material for producing high-voltage electric porcelain and daily-use porcelain. In the chemical industry, it is used as a filler for papermaking, rubber, and paint. In agriculture, it is used to produce potassium fertilizers, etc. Illite clay can be used as a flux for high-temperature-resistant cylinders and to adsorb cesium in nuclear waste treatment to prevent radiation. Illite can also be used in high-grade cosmetics, poultry feed additives, framework ingredients for high-rise buildings and cement ingredients, pollution purification in the nuclear industry, and environmental protection. Illite consists of a double-layer silicon-oxygen tetrahedron sheet and a single-layer aluminum-oxygen octahedron sheet in a TOT "sandwich" interlayer structure. In addition to the common properties of clay minerals, it also has the characteristic of a large specific surface area; the good adsorption performance of illite is related to the active sites on its surface and other related characteristics.

[0033] That is to say, there is already prior art in the field that uses illite or illite clay for nuclear waste treatment and pollution purification in the nuclear industry. However, as a natural adsorbent, the adsorption performance of illite or illite clay in its original ore is limited, which undoubtedly restricts its application. In addition, regarding the research on colloids, the current focus is mainly on bentonite, and the inventor has not found any research on illite colloids; however, exploring the ability of illite colloids to adsorb americium in a complex environment is of great significance for the leakage of radionuclides around deep geological disposal repositories. Therefore, in the present invention, a new colloidal material, namely illite colloid, is first prepared; then the application effect of this illite colloid in adsorbing europium and americium in water treatment is verified.

[0034] Example 1

[0035] This example is for the preparation of illite colloid and its characterization.

[0036] 1. Preparation of illite colloid. At room temperature, take 5.0 g of commercially available high-purity illite powder and place it in a 1 L beaker, add 500 ml of ultrapure water, ultrasonically oscillate for 1 h, let it stand for 24 h, take the supernatant and put it into a centrifuge tube, centrifuge in a centrifuge at 8000 rpm for 30 min, take out the supernatant in the centrifuge tube and put it into a plastic bottle, let the plastic bottle stand for 24 h, take the supernatant and transfer it to a washed plastic bottle, repeat twice, and finally store the obtained colloid in a 4°C constant temperature refrigerator for standby.

[0037] 2. Batch experiments were carried out by the intermittent adsorption method to test the adsorption performance of illite colloids on Eu(III). In this experiment, the effects of contact time, reaction temperature, Eu(III) concentration, colloid amount, pH value, ionic strength, and fulvic acid concentration on the adsorption of Eu(III) by illite colloids were investigated. A certain concentration of Eu(III) solution was placed in a conical flask, adjusted to the required pH value by adding negligible volumes of 1 mol / L NaOH and HCl solutions, a certain volume of illite colloid was added, and the conical flask was placed in a thermostatic shaker and shaken for half an hour. After shaking, it was placed in a centrifuge and centrifuged at 8000 rpm for 15 min. After solid-liquid separation, the supernatant was taken, and the concentration of Eu(III) in the supernatant was detected at a wavelength of 654 nm using a UV-spectrophotometer, and compared with the Eu(III) concentration in the control group to obtain the adsorption effect. According to the following formula, by measuring the concentration, the adsorption rate (S) and adsorption capacity (q e ) of the material were calculated.

[0038] (1)

[0039] (2)

[0040] In the formula, C 0 (mg / L) is the initial concentration of europium, and C e (mg / L) is the concentration of europium at adsorption equilibrium. V is the volume of the adsorption solution (mL), and m (mg) is the mass of the adsorbent.

[0041] Example 2

[0042] This example was to explore the stability of illite colloids in different hydrochemical environments.

[0043] Illite colloids were prepared batch by batch, and the changes in pH value and Zeta potential were recorded. Under alkaline conditions, when the pH was adjusted to 7, 9, and 12, the Zeta potential of illite colloids was detected and analyzed, and the stability was inferred from the change in Zeta potential after ten days. The detection results are shown as Figure 2 , Figure 2 which contains the Zeta potential of illite colloids under different pH values on the 1st, 5th, 10th, 20th, and 30th days. From Figure 2It can be seen that the absolute value of the Zeta potential of illite colloid is larger in an alkaline environment, with a higher charge density and greater stability compared to that in a neutral environment. For illite colloids at different pH values, the change in Zeta potential over time fluctuates less, indicating that illite colloids can maintain good stability for a long time. By comparing the particle size distributions of the colloids on the 5th day, 15th day, and 30th day, it can be obtained from the particle size distribution diagram that the particle size distribution range of illite colloids is mainly between 200 nm and 500 nm. Moreover, as time goes by, the change in the peak is small, the particle size of the colloid changes little, the colloid is relatively stable, and no obvious sedimentation and aggregation phenomenon occurs.

[0044] Combined with Figure 1 and Figure 2 it can be shown that as time goes by, the particle size of the illite colloid prepared by the present invention is relatively stable, no obvious sedimentation and aggregation phenomenon occurs, and the stability of the prepared illite colloid in an alkaline environment is higher than that in a neutral environment.

[0045] Example 3

[0046] This example is to explore the adsorption mechanism of illite colloid in different hydrochemical environments. The present invention first presents the SEM images of illite colloid before and after adsorbing Eu(III), as well as the analysis of adsorption kinetics and thermodynamics models.

[0047] Figure 3 are the SEM images of illite colloid before and after adsorbing Eu(III). As can be seen from Figure 3 a, before adsorption, according to the SEM image of illite colloid, it can be obtained that the illite colloid has an irregular layered structure, with a regular surface and uniform pores, which is beneficial to the adsorption of radionuclides. The SEM image of illite colloid after adsorption is shown in Figure 3 b. As can be seen from Figure 3 b, its surface is filled with irregular spherical substances, and it can be judged that a large amount of Eu(III) is adsorbed on its surface. Although the SEM image can only show the local structure of the sample, it is of great significance for analyzing the adsorption of Eu(III) by illite colloid.

[0048] Figure 4 is the relationship diagram of contact time on the adsorption of Eu(III) on illite colloid. At different contact times, the adsorption behavior of Eu(III) on illite colloid is as shown in Figure 4As shown in the figure. In the first 15 minutes, the adsorption rate of Eu(III) was relatively fast, and the adsorption rate reached 47%. From 15 minutes to 30 minutes, the adsorption rate increased slowly. After 30 minutes, the adsorption rate and adsorption capacity basically remained unchanged, reaching adsorption equilibrium. At this time, the adsorption rate was maintained at about 48%. This shows that the adsorption of Eu(III) by illite colloid is a process of rapid adsorption and rapid reaching of adsorption equilibrium. The reason is that the surface area of illite colloid is large and evenly distributed, which is conducive to providing sufficient adsorption sites for Eu(III) on its surface. The process is fast and the adsorption capacity is large. When the adsorption sites are gradually filled and saturated by the ions in the solution, the adsorption rate will decrease and gradually reach adsorption equilibrium.

[0049] Figure 5 It is the fitting curve graph of the pseudo-second-order adsorption kinetic model of the present invention. Since illite colloid has a high adsorption capacity for Eu(III) and a fast adsorption rate, it can be preliminarily judged as chemical adsorption. The pseudo-second-order kinetic model is used to analyze the adsorption behavior of illite colloid for Eu(III). The following is the pseudo-second-order adsorption kinetic equation:

[0050] (3)

[0051] In the formula, q t represents the adsorption amount of Eu(III) on illite colloid at time t, mg / g; q e represents the adsorption amount of Eu(III) on illite colloid at adsorption equilibrium, mg / g; k 2 represents the pseudo-second-order adsorption kinetic rate constant, mg / (g min). Based on the pseudo-second-order kinetic equation, plotting t / q t against t, the result is as shown in Figure 5 shown. Figure 5 Among them, the linear correlation coefficient R 2 reached 0.999, and the value of q e was 31.36 mg / g, which was relatively close to the adsorption value of 31.12 mg / g calculated from the actual experiment.

[0052] Figure 6 is the adsorption capacity curve graph of illite colloid at different temperatures and initial concentrations of Eu(III). Figure 7 is the influence of temperature on the adsorption distribution coefficient of Eu(III) on illite colloid at different solution concentrations.

[0053] The deep low-quality disposal repository will be affected by the decay heat released from the nuclides in the repository, which will affect the temperature change around the repository. The change in temperature will affect the thermal motion of molecules and may have a certain impact on the adsorption of Eu(III) by illite colloid. Figure 6The adsorption isotherms of Eu(III) on illite colloids at 298K, 308K, and 318K are shown. As the temperature increases, the adsorption amount of Eu(III) by illite colloids is higher, indicating that high temperature can promote the adsorption of Eu(III) by colloids. To further elaborate on the adsorption mechanism, the van't Hoff isotherm equation is used to determine the thermodynamic parameters of adsorption, and the equation is as follows:

[0054] (4)

[0055] (5)

[0056] (6)

[0057] where ΔG 0 represents the standard Gibbs free energy change, J·mol-1; R is the ideal gas constant, 8.3145 J·mol -1 ·K -1 ; T is the thermodynamic temperature, K; ΔS 0 is the entropy change, J·mol -1 ; ΔH 0 is the enthalpy change, J·mol -1 ; K d is the distribution coefficient, L / g.

[0058] Figure 7 The adsorption isotherms of illite colloids for Eu(III) at 298K, 308K, and 318K are described. By plotting lnK d against 1 / T, as shown in the figure, ΔH 0 and ΔS 0 values are obtained from the slope and intercept. According to the above equation, ΔG 0 is calculated. All the thermodynamic parameters, ΔH 0 and ΔS 0 are positive, and ΔG 0 is negative, so this adsorption behavior is a spontaneous endothermic reaction. It can be seen that the values of ΔH 0 and ΔS 0 decrease with the increase in the concentration of Eu(III). This may be because at low Eu(III) concentrations, the adsorption sites are sufficient, and the adsorption reaction occurs more easily and preferentially at the adsorbable sites, and the adsorption of Eu(III) on the colloids at these sites is also better. Although the adsorption amount of the colloid can be increased at high concentrations, the adsorption rate will gradually decrease. Figure 7 In Figure 7 , the concentration of europium in water is 1.6 - 4.8 mg / L.

[0059] Figure 8 is the Langmuir model diagram. Figure 9This is a Freundlich model diagram. To further elaborate on the adsorption mechanism of illite colloids, the Langmuir and Freundlich thermodynamic models were used to fit the adsorption isotherm of Eu(III) on illite colloids, as shown in Figure 8 and 9 shown. The linear expressions of the two equations are as follows:

[0060] Linear expression of Langmuir:

[0061] (7)

[0062] Linear expression of Freundlich:

[0063] (8)

[0064] where C e is the adsorption equilibrium concentration of europium, mg / L; q e is the adsorption capacity at adsorption equilibrium, mg / g; q m is the maximum adsorption capacity; K is the adsorption amount when the Eu(III) concentration is 1 mg / L; A is the Langmuir constant; B is the Freundlich constant.

[0065] Figure 8 and Figure 9 represent the linear fitting of the Langmuir and Freundlich isothermal adsorption models. It can be concluded that the Langmuir isothermal adsorption model has a better fitting effect than Freundlich, and the maximum adsorption capacity q m fitted is also relatively close to the experimental test value, which can better describe the adsorption process of Eu(III) on illite colloids, indicating that the adsorption performance of the illite colloid surface for Eu(III) is uniform and it is a monolayer adsorption.

[0066] Figure 10is the adsorption rate of illite colloid at different pH values. The acidity and alkalinity of the solution will have a certain impact on the properties of illite colloid, or cause certain changes in the chemical form of Eu(III). Therefore, the pH value of the solution is an important reference factor affecting the adsorption of Eu(III) by illite colloid. The figure shows that when the initial concentration of Eu(III) is different and pH = 6 - 11, the adsorption amount of illite colloid to Eu(III) gradually increases with the increase of pH value. When pH = 11 and the initial concentration of Eu(III) is 1.6 mg / L, the adsorption rate reaches 93%. A large amount of aggregation of illite colloid will occur under the condition that the pH value is lower than 4. Therefore, the adsorption performance of the colloid is poor under acidic conditions. The colloid is relatively stable when pH is higher than 5, and the electrostatic attraction between europium ions and the negative surface of the colloid gradually increases with the increase of pH value. The adsorption performance of illite colloid to Eu(III) is better in neutral and alkaline environments. When pH < 7, Eu(III) in the solution mainly exists in the form of Eu 3+ When the solution is weakly alkaline (pH < 8), the content of Eu 3+ in the solution will gradually decrease, and the content of EuOH 2+ , Eu(OH) 2 + will gradually increase, but it still mainly exists in the form of Eu 3+ . Under the condition of pH < 8, the adsorption mechanism of illite colloid is mainly the complexation between the surface groups of the colloid and Eu 3+ . When the solution is under strong alkaline conditions, Eu(III) in the solution mainly exists in the form of hydrolysis products such as Eu(OH) 3 and so on.

[0067] Figure 11 shows the influence of fulvic acid on the adsorption of Eu(III) on illite colloid. Humic acid is a macromolecular organic substance widely existing in nature. Fulvic acid, also called fulvic acid, is a kind of organic acid with very small molecular weight in humic acid. In this invention, fulvic acid is taken as an example to explore its influence on the adsorption of Eu(III) by illite colloid. As shown in the figure, when pH < 8, fulvic acid has a promoting effect on the adsorption of Eu(III). This may be because the surface of fulvic acid contains functional groups such as hydroxyl groups, phenolic hydroxyl groups, and carboxyl groups, which complex with Eu(III) and carry Eu(III) adsorbed on the illite colloid. When in an environment with pH > 8, the presence of fulvic acid has a slight adverse effect on the adsorption of Eu(III) by illite colloid. This may be because fulvic acid and Eu(III) form a complex under alkaline conditions, making it difficult to adsorb on the illite colloid. Therefore, when illite colloid is used to adsorb Eu(III) at pH < 8, a certain amount of humic acid, such as fulvic acid, can be added to the water.

[0068] Figure 12Effect of ionic strength on adsorption. In the groundwater environment of fractures around a deep geological disposal repository, there are various ions. The adsorption of Eu(III) on illite colloids is mainly dominated by outer surface coordination, and the ionic strength will affect the coordination adsorption of Eu(III) on illite colloids. In the present invention, the effects of different concentrations of NaCl on the adsorption of Eu(III) on illite colloids were analyzed respectively. It was found through experiments that when the NaCl concentration was in the range of 0 to 0.01 M, the effects of different concentrations of NaCl on the adsorption of Eu(III) on illite colloids were not significant.

[0069] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present invention and is not used to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An application of a colloidal material for adsorbing metal elements in a groundwater environment, characterized in that: The colloidal material is illite colloid, and the illite colloid is used to adsorb the metal element europium or americium. The amount of illite colloid used is 0.5-2 g / L, the contact time between the illite colloid and the water containing europium or americium is more than 10 minutes, the initial concentration of europium or americium in the water is more than 0.3 mg / L, and the adsorption reaction temperature between the illite colloid and the water containing europium or americium is more than 20°C; The preparation method of illite colloid comprises the following steps: firstly mixing illite powder with ultrapure water or deionized water, ultrasonically oscillating the mixture and allowing the mixture to stand for a period of time, centrifuging the supernatant in a centrifuge tube, allowing the supernatant to stand in a first container, transferring the supernatant of the first container to a second container and allowing the supernatant to stand, and then transferring the supernatant of the second container to a third container, so as to obtain the illite colloid; and the weight ratio of the illite powder to the ultrapure water or deionized water is 1:50-200, the ultrasonic oscillation time is 10 minutes to 10 hours, and the standing time after the ultrasonic oscillation is more than 12 hours; the centrifugal speed is more than 4000 rpm, and the centrifugal time is more than 10 minutes; the standing time of the supernatant in the first container is more than 24 hours, and the standing time of the supernatant in the second container is more than 24 hours; the illite colloid is stored in a refrigerator at 2-8°C for standby use, and the pH value of the illite colloid is adjusted to 9-12 before storing the illite colloid.

2. The use according to claim 1, characterized in that: The initial concentration of europium or americium in the water is 1.6-4.8 mg / L.

3. The use according to claim 1, characterized in that: The contact time of the illite colloid and the water containing europium or americium is 15 to 60 minutes, and the adsorption reaction temperature of the illite colloid and the water containing europium or americium is above 40°C.

4. The use according to claim 1, characterized in that: The pH value of the water containing europium or americium is 8 or more.

5. The use according to claim 1, characterized in that: The pH value of the water containing europium or americium is below 8, and alkali or fulvic acid is added to the water containing europium or americium for pretreatment.

6. The use according to claim 1, characterized in that: In the preparation method, the weight ratio of the illite powder to ultrapure water or deionized water is 1:80~150; the ultrasonic oscillation time is 0.5~3 hours; and the standing time after the ultrasonic oscillation is more than 24 hours; the centrifugal speed is 7000~10000rpm; the centrifugal time is more than 30min; the first container is a plastic container or a glass container, and the second container is a plastic container or a glass container.

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