A nuclide-enriched material, an enriched adsorption column comprising the material, and a preparation method and application thereof

Abstract

The present application discloses a kind of nuclide enrichment material and enrichment adsorption column comprising the material, its preparation method and application, the nuclide enrichment material is the composition of K·Ag·Fe·Co (CN) 6 and MnO2, can adsorb multiple gamma nuclide.Nuclide enrichment adsorption column is to use the above-mentioned material as adsorbent, can simultaneously adsorb multiple gamma nuclide, can be used for the direct measurement of gamma nuclide in liquid sample, and there is no obvious requirement to the pH of water body.The adsorption column can meet all requirements of our country radiation environment monitoring, radiation environment quality monitoring, liquid effluent monitoring to the type of gamma nuclide in liquid sample monitoring.

Description

Technical Field

[0001] This invention relates to the technical field of γ-nucleus enrichment, specifically to a nuclide enrichment material, a nuclide enrichment adsorption column, its preparation method, and its application. Background Technology

[0002] Effluent monitoring is a crucial aspect of radiation monitoring at nuclear power plants. It involves measuring the activity concentration of gaseous and liquid radioactive effluents released into the surrounding environment to determine whether annual emissions meet regulatory and standard requirements, thus ensuring the safe operation of the nuclear power plant. Furthermore, as a type of nuclear facility with complex structures and extremely high safety requirements, nuclear power plants encompass various types of radioactive pollution monitoring. Their effluent monitoring and supervision are the most comprehensive and representative, providing a reference for the monitoring and supervision of other nuclear and radiation facilities. Nuclear power plant wastewater has a high tritium content, making conventional methods (evaporation concentration, co-precipitation) unsuitable for sample enrichment. Currently, direct measurement methods are commonly used for monitoring liquid effluents from nuclear power plants. However, the detection limit of this method is more than 10 times higher than that of environmental sample measurement methods. This results in significant uncertainty in statistical data when calculating emissions.

[0003] According to the relevant provisions of the "Technical Specification for Environmental Emergency Monitoring of Nuclear Power Plants" (HJ1128-2020) and the "Technical Specification for Emergency Monitoring of Radiation Accidents" (HJ1155-2020), when a nuclear accident or radiation accident occurs, the surrounding environment should be sampled and analyzed as soon as possible. In the case of a nuclear accident, the monitoring of terrestrial environmental water and seawater discharged from liquid effluent outlets is particularly important. In the event of an accident, monitoring agencies are required to be able to analyze water samples quickly. However, existing monitoring technologies are time-consuming and cannot achieve rapid and accurate analysis.

[0004] Currently, there are no commercially available columns for enriching gamma nuclides in liquids. Although research has explored this topic, most studies involve loading one type of adsorbent onto a single enrichment column, which can effectively adsorb 1-3 nuclides. However, there are many types of gamma nuclides in the environment. Just from the liquid effluents from nuclear power plants, there are more than a dozen gamma nuclides that require special attention. If we want to enrich all the nuclides of interest, we need to connect multiple enrichment columns of different types in series, which is complicated and not convenient for direct measurement. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, one objective of this invention is to provide a radionuclide enrichment material comprising a composition of K·Ag·Fe·Co(CN)6 and MnO2, capable of adsorbing multiple γ-nuclides. A second objective is to provide a radionuclide enrichment adsorption column, using the aforementioned material as an adsorbent, capable of simultaneously adsorbing multiple γ-nuclides for convenient direct measurement. A third objective is to provide a method for preparing a radionuclide enrichment adsorption column, employing a circulating filtration process to attach the adsorbent to the column; this method is simple and suitable for large-scale production. A fourth objective is to provide an application of the radionuclide enrichment adsorption column for the detection of multiple γ-nuclides in liquid samples, with a wide range of applicability.

[0006] One of the objectives of this invention is achieved through the following technical solution:

[0007] A nuclide enrichment material comprising K·Ag·Fe·Co(CN)6 and MnO2.

[0008] Furthermore, the molar ratio of MnO2 to K·Ag·Fe·Co(CN)6 is 0.1:1 to 1:1; and the particle size of MnO2 is 100 to 200 mesh.

[0009] Specifically, the preparation method of K·Ag·Fe·Co(CN)6 includes the following steps:

[0010] 1) Prepare a cobalt nitrate solution, then add silver nitrate solid, stir until homogeneous, and obtain a mixed solution;

[0011] 2) Prepare a potassium ferrocyanate trihydrate solution;

[0012] 3) Mix the solution from step 1) with the solution from step 2), stir, let stand, and a precipitate will form to obtain a turbid liquid containing K·Ag·Fe·Co(CN)6.

[0013] Furthermore, the mass concentration of the cobalt nitrate solution is 0.1–0.5 mol / L; the mass concentration of silver nitrate in the mixed solution is 0.008–0.05 mol / L; and the mass concentration of the potassium ferrocyanate trihydrate solution is 0.1–0.5 mol / L.

[0014] Furthermore, the molar ratio of cobalt nitrate, silver nitrate, and potassium ferrocyanate trihydrate is 1:(0.08~1):1.

[0015] The second objective of this invention is achieved by the following technical solution:

[0016] A radionuclide enrichment adsorption column, wherein the adsorbent used in the adsorption column is the aforementioned radionuclide enrichment material.

[0017] The third objective of this invention is achieved by the following technical solution:

[0018] The preparation method of the above-mentioned radionuclide enrichment adsorption column includes the following steps:

[0019] 1) First, activate the blank column to obtain an activated column;

[0020] 2) The activated column is then immersed in a turbid solution containing K·Ag·Fe·Co(CN)6. After the activated column is removed, it is dried to obtain an adsorption column with K·Ag·Fe·Co(CN)6 attached.

[0021] 3) The adsorption column from step 2) is immersed in a suspension of MnO2 powder for cyclic adsorption. After drying, a radionuclide enrichment adsorption column is obtained.

[0022] Furthermore, the activation treatment includes the following steps: first, soaking the blank column in hydrochloric acid, then soaking it in sodium hydroxide solution, and removing the blank column; next, soaking it in sodium dodecylbenzenesulfonate solution, removing it, washing it with distilled water until the washing water is neutral, and drying it to obtain the activated column. Ordinary blank columns are hydrophobic, which is not conducive to adsorbent adhesion. Sodium dodecylbenzenesulfonate is an effective surfactant; after treatment, the hydrophobicity of the column is effectively improved, facilitating subsequent operations.

[0023] Furthermore, the blank column is a polypropylene fiber column.

[0024] The fourth objective of this invention is achieved by the following technical solution:

[0025] The above-mentioned application of the radionuclide enrichment adsorption column is that the radionuclide enrichment adsorption column is used for the detection of γ radionuclides in liquid samples.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] (1) The nuclide enrichment material of the present invention is a combination of K·Ag·Fe·Co(CN)6 and MnO2, which can effectively adsorb a variety of γ nuclides, specifically, it can effectively adsorb pure β nuclides such as Strontium-90 and Nickel-63. Strontium-90 and Nickel-63 are key nuclides of concern in liquid effluents from nuclear power plants. The specific principle of K·Ag·Fe·Co(CN)6 adsorbing nuclides is: surface adsorption and carrier; MnO2 can effectively adsorb metal components such as manganese, strontium and nickel, and can also provide a large adsorption area.

[0028] (2) The nuclide enrichment adsorption column of the present invention uses the above-mentioned material as an adsorbent, which can simultaneously adsorb multiple γ nuclides, facilitating direct measurement. It can effectively adsorb pure β nuclide strontium-90. However, due to the high tritium content in its liquid effluent, radiochemical analysis carries a significant risk. By adsorbing these two nuclides onto the enrichment adsorption column and then performing analysis and measurement after desorption, the influence of tritium on the staff is avoided.

[0029] (3) The radionuclide enrichment adsorption column of the present invention is used for the detection of γ-nuclides in liquid samples. Liquid samples include, but are not limited to, rainwater, snow water, surface water, groundwater, drinking water, seawater, and nuclear power plant wastewater, etc., and have no significant requirements on the pH of the water body. Experiments have shown that good adsorption effects can be obtained at pH = 2 to 9. This adsorption column can meet all the requirements of my country's radiation environment monitoring, radiation environment quality monitoring, and liquid effluent monitoring for the types of γ-nuclides to be detected in liquid samples.

[0030] (3) The radionuclide enrichment adsorption column of this invention has a large enrichment capacity, capable of enriching at least 50L of seawater, and an even larger enrichment capacity for terrestrial water. It also lowers the detection limit for effluent monitoring, maintaining it at the same level as the seawater detection limit. Using the enrichment column allows effluent to reach seawater levels, far below the current lower detection limit for effluent monitoring, improving data accuracy and thus enhancing the effectiveness of environmental water sample monitoring. This adsorption column can also rapidly enrich radionuclides, with a sample flow rate of up to 3L / min, improving analytical efficiency and reducing analysis time. It can be used for rapid measurements in nuclear accident emergency situations. Detailed Implementation

[0031] The present invention will now be further described in conjunction with specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0032] Example 1

[0033] A method for preparing a radionuclide enrichment adsorption column, wherein the adsorbent used in the adsorption column is a radionuclide enrichment material, comprising the following steps:

[0034] 1) First, activate the blank column to obtain an activated column;

[0035] 2) The activated column is then immersed in a turbid solution containing K·Ag·Fe·Co(CN)6 for 30 minutes. After the activated column is removed, it is placed in an oven at 60°C for drying, so that most of the adsorbent can adhere tightly to the column and the water flow will not wash it off, thus obtaining an adsorption column with K·Ag·Fe·Co(CN)6 attached.

[0036] 3) The adsorption column from step 2) is immersed in a suspension of MnO2 powder for cyclic adsorption. After drying, a radionuclide enrichment adsorption column is obtained.

[0037] The activation treatment includes the following steps: soaking the column in 0.5 mol / L hydrochloric acid at 60°C for 12 hours, then transferring it to a 0.5 mol / L sodium hydroxide solution and soaking it at 60°C for 12 hours. The blank column is then removed and soaked in a 0.3 g / L sodium dodecylbenzenesulfonate solution at 60°C for 3-5 hours. After removal, the column is washed with distilled water until the washing water is neutral, and then dried in an oven at 60°C to obtain the activated column. The blank column is a polypropylene fiber column with a pore size of 5 μm. The molar ratio of MnO2 to K·Ag·Fe·Co(CN)6 in the radionuclide enrichment material is 1:1; the MnO2 particle size in the MnO2 powder suspension is 100 mesh.

[0038] The preparation method of the K·Ag·Fe·Co(CN)6 turbid liquid includes the following steps:

[0039] 1) Prepare a cobalt nitrate solution with a mass concentration of 0.1 mol / L, then add silver nitrate solid to make its mass concentration 0.0088 mol / L (1.5 g / L), stir well to obtain a mixed solution;

[0040] 2) Prepare a 0.1 mol / L potassium ferrocyanate trihydrate solution;

[0041] 3) Mix the solution from step 1) with the solution from step 2), stir, let stand, and a precipitate will form to obtain a turbid liquid containing K·Ag·Fe·Co(CN)6.

[0042] Example 2

[0043] A method for preparing a radionuclide enrichment adsorption column, wherein the adsorbent used in the adsorption column is a radionuclide enrichment material, comprising the following steps:

[0044] 1) First, activate the blank column to obtain an activated column;

[0045] 2) The activated column is then immersed in a turbid solution containing K·Ag·Fe·Co(CN)6 for 30 minutes. After the activated column is removed, it is placed in an oven at 60°C for drying, so that most of the adsorbent can adhere tightly to the column and the water flow will not wash it off, thus obtaining an adsorption column with K·Ag·Fe·Co(CN)6 attached.

[0046] 3) The adsorption column from step 2) is immersed in a suspension of MnO2 powder for cyclic adsorption. After drying, a radionuclide enrichment adsorption column is obtained.

[0047] The activation treatment includes the following steps: soaking the column in 0.5 mol / L hydrochloric acid at 60°C for 12 hours, then transferring it to a 0.5 mol / L sodium hydroxide solution and soaking it at 60°C for 12 hours. The blank column is then removed and soaked in a 0.3 g / L sodium dodecylbenzenesulfonate solution at 60°C for 3-5 hours. After removal, the column is washed with distilled water until the washing water is neutral, and then dried in an oven at 60°C to obtain the activated column. The blank column is a polypropylene fiber column with a pore size of 5 μm. The molar ratio of MnO2 to K·Ag·Fe·Co(CN)6 in the radionuclide enrichment material is 0.5:1; the MnO2 particle size in the MnO2 powder suspension is 150 mesh.

[0048] The preparation method of the K·Ag·Fe·Co(CN)6 turbid liquid includes the following steps:

[0049] 1) Prepare a cobalt nitrate solution with a mass concentration of 0.2 mol / L, then add silver nitrate solid to make its mass concentration 0.016 mol / L and stir until homogeneous to obtain a mixed solution;

[0050] 2) Prepare a 0.2 mol / L potassium ferrocyanate trihydrate solution;

[0051] 3) Mix the solution from step 1) with the solution from step 2), stir, let stand, and a precipitate will form to obtain a turbid liquid containing K·Ag·Fe·Co(CN)6.

[0052] Example 3

[0053] A method for preparing a radionuclide enrichment adsorption column, wherein the adsorbent used in the adsorption column is a radionuclide enrichment material, comprising the following steps:

[0054] 1) First, activate the blank column to obtain an activated column;

[0055] 2) The activated column is then immersed in a turbid solution containing K·Ag·Fe·Co(CN)6 for 30 minutes. After the activated column is removed, it is placed in an oven at 60°C for drying, so that most of the adsorbent can adhere tightly to the column and the water flow will not wash it off, thus obtaining an adsorption column with K·Ag·Fe·Co(CN)6 attached.

[0056] 3) The adsorption column from step 2) is immersed in a suspension of MnO2 powder for cyclic adsorption. After drying, a radionuclide enrichment adsorption column is obtained.

[0057] The activation treatment includes the following steps: soaking the column in 0.5 mol / L hydrochloric acid at 60°C for 12 hours, then transferring it to a 0.5 mol / L sodium hydroxide solution and soaking it at 60°C for 12 hours. The blank column is then removed and soaked in a 0.3 g / L sodium dodecylbenzenesulfonate solution at 60°C for 3-5 hours. After removal, the column is washed with distilled water until the washing water is neutral, and then dried in an oven at 60°C to obtain the activated column. The blank column is a polypropylene fiber column with a pore size of 5 μm. The molar ratio of MnO2 to K·Ag·Fe·Co(CN)6 in the radionuclide enrichment material is [value missing]; the MnO2 particle size in the MnO2 powder suspension is 200 mesh.

[0058] The preparation method of the K·Ag·Fe·Co(CN)6 turbid liquid includes the following steps:

[0059] 1) Prepare a cobalt nitrate solution with a mass concentration of 1 mol / L, then add silver nitrate solid to make its mass concentration 0.05 mol / L and stir evenly to obtain a mixed solution;

[0060] 2) Prepare a 0.5 mol / L potassium ferrocyanate trihydrate solution;

[0061] 3) Mix the solution from step 1) with the solution from step 2), stir, let stand, and a precipitate will form to obtain a turbid liquid containing K·Ag·Fe·Co(CN)6.

[0062] Comparative Example 1

[0063] The difference between Comparative Example 1 and Example 1 is that the adsorption column of Comparative Example 1 was only supplemented with the same amount of K·Ag·Fe·Co(CN)6 as the adsorbent as that of Example 1.

[0064] Comparative Example 2

[0065] The difference between Comparative Example 2 and Example 1 is that the adsorption column of Comparative Example 2 only added the same amount of MnO2 as that of Example 1 as the adsorbent.

[0066] Chemical composition testing

[0067] To verify the chemical elements contained in K·Ag·Fe·Co(CN)6, polarization-excited X-ray fluorescence spectrometry (EDXRF) was used to test the chemical elements in the adsorption column of Comparative Example 1. Since the adsorption column of Comparative Example 1 contains only one adsorbent, interference from other elements can be reduced. Specific data are shown in Table 1.

[0068] Table 1. Test results of the adsorption column in Comparative Example 1

[0069] element content(%) K 28.536 Fe 23.714 Ag 22.024 Co 21.54 Al 3.957 S 0.229

[0070] As shown in Table 1, the adsorption column of Comparative Example 1 contains K, Co, Fe, Ag, Al, and S, which are known. Al and S are provided by the activation column itself, so the remaining K, Co, Fe, and Ag are provided by K·Ag·Fe·Co(CN)6. Moreover, the mass ratio of the four is close to 1:1:1:1.

[0071] Performance testing

[0072] I. Adsorption effect test

[0073] The experiment was divided into three groups: the adsorption columns of Example 1 and Comparative Examples 1 and 2. For each group, 210g of the same source of raw liquid (nuclear power plant waste liquid) was passed into the corresponding adsorption column at a flow rate of 3L / min for 2 hours. The pH of the raw liquid was 2. The radionuclide activity and adsorption efficiency data before and after column permeation for each group are shown in Table 1.

[0074] Table 1. Nuclide activity and adsorption efficiency data of each group of original solutions before and after column chromatography.

[0075]

[0076]

[0077] As shown in Table 2, Example 1 showed better adsorption performance compared to Comparative Examples 1 and 2, indicating that the combination of K·Ag·Fe·Co(CN)6 and MnO2 as adsorbents can significantly improve the adsorption effect of the adsorption column.

[0078] II. Test on the effect of pH on adsorption efficiency

[0079] The experiment was divided into three groups. In each group, 210g of the same source of raw liquid (nuclear power plant waste liquid) was introduced into the adsorption column of Example 1 at a flow rate of 3L / min and the adsorption time was 2h. The pH of the raw liquid was adjusted to 2, 7 and 9 respectively, and the activity and adsorption efficiency of enriched nuclides at different pH values ​​were detected. See Table 2 for details.

[0080] Table 2. Activity and adsorption efficiency data of enriched nuclides at different pH values.

[0081]

[0082]

[0083] As shown in Table 2, the adsorption column of Example 1 showed no significant difference in adsorption effect on water bodies with pH values ​​of 2, 7, and 9. It can be used for the enrichment of nuclides in various water bodies such as rainwater, snow water, surface water, groundwater, drinking water, seawater, and nuclear power plant wastewater, and has a wide range of applications.

[0084] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. An isotope-enriched material, characterized by, The materials include KAgFeCo(CN)6 and MnO2; The preparation method of the KAgFeCo(CN)6 includes the following steps: 1) Prepare a cobalt nitrate solution, then add silver nitrate solid, stir until homogeneous, and obtain a mixed solution; 2) Prepare a potassium ferrocyanate trihydrate solution; 3) Mix the solution from step 1) with the solution from step 2), stir, let stand, and a precipitate will form to obtain a turbid liquid containing KAgFeCo(CN)6.

2. The isotope-enriched material of claim 1, wherein, The molar ratio of MnO2 to KAgFeCo(CN)6 is 0.1:1 to 1:1; the particle size of MnO2 is 100 to 200 mesh.

3. The isotope-enriched material of claim 1, wherein, The cobalt nitrate solution has a molar concentration of 0.5–1 mol / L; the silver nitrate solution in the mixed solution has a molar concentration of 0.008–0.5 mol / L; and the potassium ferrocyanate trihydrate solution has a molar concentration of 0.1–0.5 mol / L.

4. The isotope-enriched material of claim 1, wherein, The molar ratio of cobalt nitrate, silver nitrate and potassium ferrocyanate trihydrate is 1:(0.08~1):

1.

5. A species-enriching adsorption column, characterized by, The adsorbent used in the adsorption column is the nuclide enrichment material according to any one of claims 1 to 4.

6. The method of claim 5, wherein the isotope-enriched adsorption column is prepared by the steps of: Includes the following steps: 1) First, activate the blank column to obtain an activated column; 2) The activated column is then immersed in a turbid solution containing KAGFeCo(CN)6. After the activated column is removed, it is dried to obtain an adsorption column with KAGFeCo(CN)6 attached. 3) The adsorption column from step 2) is immersed in a suspension of MnO2 powder for cyclic adsorption. After drying, a radionuclide enrichment adsorption column is obtained.

7. The method for preparing the radionuclide enrichment adsorption column as described in claim 6, characterized in that, The activation treatment includes the following steps: first, soak the blank column in hydrochloric acid, then soak it in sodium hydroxide solution, and remove the blank column; then soak it in sodium dodecylbenzenesulfonate solution, remove it, wash it with distilled water until the washing water is neutral, and dry it to obtain the activated column.

8. The method for preparing the radionuclide enrichment adsorption column as described in claim 6, characterized in that, The blank column is a polypropylene fiber column.

9. Use of the isotope-enriched adsorption column according to claim 5, characterized in that The radionuclide enrichment adsorption column is used for the detection of γ radionuclides in liquid samples.

Images