A large volume of water 137 Cs enrichment and analysis methods

Abstract

This invention relates to a large-volume underwater... 137 The Cs enrichment and analysis method belongs to the field of radionuclide analysis. It involves taking a pre-set large volume water sample and placing it in a container. While stirring, an acid solution is added to the container to adjust the solution to acidity. While stirring, a pre-set amount of potassium cobalt ferrocyanide is added to the container, and the mixture is stirred and allowed to stand. The supernatant is removed, and the precipitate is then transferred to a centrifuge. The precipitate is then centrifuged to remove moisture. The precipitate is then transferred to an oven for drying and grinding. The dried and ground precipitate is then subjected to further processing. 137 Cs content measurement. Using the method disclosed in this invention, potassium cobalt ferrocyanide was used to measure the Cs content in a large volume water sample. 137 Cs enrichment and analysis can overcome the limitations of traditional methods using ammonium phosphomolybdate for enrichment and analysis. 137 To overcome the drawbacks of Cs precipitation during the process, such as precipitation and easy adsorption onto the solution wall, this study aims to improve the recovery rate of the enrichment analysis process and reduce the difficulty of enrichment analysis.

Description

Technical Field

[0001] This invention belongs to the field of radionuclide analysis, specifically relating to a method for analyzing large volumes of water containing radionuclides. 137 Cs enrichment and analysis methods. Background Technology

[0002] 137 Cs is the main artificial radionuclide released during nuclear explosions and the operation of nuclear facilities. Most of these radioactive materials eventually fall into surface water, oceans and other water bodies through various pathways, causing a certain degree of radioactive pollution to the environment. 137 Cs has a relatively long physical half-life of 30.17 years and chemical properties similar to... 40 K can enter organisms through the food chain, endangering marine life and human safety.

[0003] According to the "Technical Specification for Radiation Environmental Monitoring" (HJ 61-2021), during the operation of nuclear facilities, the unit must monitor the environment for radiation. 137 Cs are monitored. This includes surface water, drinking water, groundwater, and marine water. 137 Monitoring of Cs is an important component. Because of the presence of Cs in environmental water... 137 The concentration of Cs is extremely low, generally requiring pre-concentration with a large volume of water (50L-100L) before measurement. Currently, in environmental water... 137 The measurement of Cs was mainly carried out according to the standards of "Gamma Spectrometry Analysis Method for Radionuclides in Water" (GBT 16140-2018) and "Radiochemical Analysis Method for Cesium-137 in Ash of Water and Biological Samples" (HJ 816-2016): First, ammonium phosphomolybdate was used to analyze the water sample (>50L). 137 Cs are enriched, then centrifuged or purified for subsequent measurements. Currently, some literature reports also use this method, such as the paper "Cs in Seawater" by Liu Junfeng, Pan Jianming, et al. 137 "Enrichment and Analysis of Cs", and "Determination of Large Volume Cs by HPGe Spectrometer" by Xu Jia'ang, Chen Yingmin, et al. 137 Research on the Cs method. When using ammonium phosphomolybdate for enrichment, the precipitate generated in practical applications does not completely settle; some precipitate floats on the water surface and easily adheres to the container at the bottom, making it difficult to collect and resulting in a low recovery rate.

[0004] Currently, some laboratories are using distillation to enrich ammonium phosphomolybdate in order to overcome its drawbacks. However, the distillation rate is too slow, especially for seawater, where the salinity is too high, there are too many impurities, the distillation vessel is difficult to select, and it causes great difficulties for subsequent analysis.

[0005] Therefore, it is necessary to find a new precipitant for large volumes of water. 137The enrichment and analysis of Cs is of great significance. For example, Sun Yongxia published "A Study on the Mechanism of Cs+ Adsorption by Potassium Ferrocyanide Titanium", which is used in the treatment of wastewater in nearby areas. 137 Cs, however, is a complex precipitant to produce and has not been used in environmental water bodies. In the National Food Safety Standard for the Determination of Radioactive Substances Cesium-137 in Food (GB 14883.10-2016), potassium cobalt ferrocyanide is used to enrich the extract (50 mL) of Cesium-137. 137 Cs. During the analysis, potassium cobalt ferrocyanide was found to be enriched in the extract. 137 The precipitate formed by Cs did not exhibit floating and settled completely. However, due to the small volume and low impurity content of the collected extract, it differs significantly from actual water samples. Whether it is suitable for large-volume environmental water samples requires experimental verification. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a large-volume underwater [technology / method]. 137 Cs enrichment and analysis method, using potassium cobalt ferrocyanide for the enrichment and analysis of Cs in large volume water samples. 137 Cs enrichment and analysis can overcome the limitations of traditional methods using ammonium phosphomolybdate for enrichment and analysis. 137 To overcome the drawbacks of Cs precipitation during the process, such as precipitation and easy adsorption onto the solution wall, this study aims to improve the recovery rate of the enrichment analysis process and reduce the difficulty of enrichment analysis.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: a large-volume underwater... 137 Cs enrichment and analysis method, the method comprising the following steps:

[0008] S1. Take a preset large volume water sample and put it into a container. While stirring, add an acid solution to the container to adjust the solution to acidity.

[0009] S2. While stirring, continue to add a preset amount of potassium cobalt ferrocyanide to the container, stir and let stand;

[0010] S3. Remove the supernatant and then transfer the precipitate into a centrifuge.

[0011] S4. Place the precipitate from step S3 into a centrifuge and centrifuge to remove moisture;

[0012] S5. Transfer the precipitate from step S4 to an oven for drying and grinding;

[0013] S6. The precipitate after drying and grinding in step S5 is then subjected to... 137 Cs content measurement.

[0014] Furthermore, the acid solution in step S1 includes hydrochloric acid and nitric acid.

[0015] Furthermore, in step S2, the amount of potassium cobalt ferrocyanide is 1.6g of potassium cobalt ferrocyanide added to every 10L of water sample.

[0016] Furthermore, in step S6, the precipitate dried and ground in step S5 is placed into a γ box for further processing. 137 Cs content measurement.

[0017] Furthermore, in step S1, the amount of acid solution added to the container is 1 mL of acidic substance added to every 10 L of water sample.

[0018] Further, in step S5, the precipitate from step S4 is transferred to an oven and dried at 110°C, and then ground.

[0019] Furthermore, the centrifugation device in step S3 is a centrifuge bottle.

[0020] Furthermore, in step S1, the preset large-volume water sample is a 50L water sample.

[0021] The beneficial technical effects of this invention are as follows: Using the large-volume underwater [method / technology] disclosed in this invention... 137 The method of Cs enrichment and analysis uses potassium cobalt ferrocyanide for the enrichment and analysis of Cs in large volume water samples. 137 Cs enrichment and analysis can overcome the limitations of traditional methods using ammonium phosphomolybdate for enrichment and analysis. 137 The disadvantage of Cs is that the generated precipitate can float completely and does not adhere to the solution wall, thus improving the recovery rate and the degree of analysis. Attached Figure Description

[0022] Figure 1 A large-volume underwater [method] as described in the embodiments of the present invention 137 Flowchart of Cs enrichment and analysis method. Detailed Implementation

[0023] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0024] Example 1

[0025] like Figure 1 As shown, this embodiment of the invention provides a large-volume underwater... 137 A method for Cs enrichment and analysis, the method comprising the following steps:

[0026] S1. Take 50L of water sample and put it into a container. Turn on the stirrer and add 5mL of hydrochloric acid to the container to adjust the solution to acidity.

[0027] In this embodiment, the solution is adjusted to acidity by adding hydrochloric acid to the container; in fact, the solution can also be adjusted to acidity by adding nitric acid to the container.

[0028] S2. While stirring, add 8g of potassium cobalt ferrocyanide to the container, stir for 40min, and let stand for more than 12h.

[0029] S3. Remove the supernatant and then transfer the precipitate into a 500mL centrifuge bottle;

[0030] S4. Place the precipitate from step S3 into a centrifuge and centrifuge to remove moisture;

[0031] S5. Transfer the precipitate from step S4 to a petri dish, dry it in an oven at 110°C, and grind it.

[0032] S6. Place the dried precipitate from step S5 into a γ box for further processing. 137 Cs content measurement.

[0033] In this embodiment, the following experiment is used to verify the large-volume underwater [method / technology] disclosed in this embodiment of the invention. 137 Creativity in Cs enrichment and analysis methods.

[0034] S11. Take six 50L parallel water samples and place them into six 100L containers respectively. While stirring, add 5mL of hydrochloric acid to each container to adjust the solution to acidity, and then add 100Bq of hydrochloric acid to each container. 134 Cs tracer.

[0035] S12. While stirring, add 8g of potassium cobalt ferrocyanide to each of the six containers, stir for 40min, and let stand for more than 12h.

[0036] S13. Remove the supernatant, and then transfer the precipitate into 500mL centrifuge bottles respectively;

[0037] S14. Place the precipitate from step S13 into a centrifuge and centrifuge to remove moisture;

[0038] S15. Transfer the precipitate from step S14 to a petri dish, dry it in an oven at 110°C, and grind it.

[0039] S16. Place the dried precipitate from step S15 into γ boxes for further processing. 134 Cs content measurement and analysis 134 The Cs recovery rate and precision, and the analytical results are shown in Table 1.

[0040] Table 1 Large Volume Water 134 Cs recovery rate and precision analysis table

[0041]

[0042]

[0043] As can be seen from the table: 134 The recovery rate of Cs was greater than 95%, and the precision was 1.4%, indicating that the analytical method was stable and accurate.

[0044] As can be seen from the above embodiments, the large-volume underwater [substance] disclosed in this invention... 137 The Cs enrichment and analysis method involves taking a pre-set large volume water sample and placing it in a container. While stirring, an acid solution is added to the container to adjust the solution to acidity. While stirring, a pre-set amount of potassium cobalt ferrocyanide is added to the container, and the mixture is stirred and allowed to stand. The supernatant is removed, and the precipitate is transferred to a centrifuge. The precipitate is then centrifuged to remove moisture. The precipitate is transferred to an oven for drying and grinding. The dried and ground precipitate is then subjected to further processing. 137 Cs content measurement. Using the method disclosed in this invention, potassium cobalt ferrocyanide was used to measure the Cs content in a large volume water sample. 137 Cs enrichment and analysis can overcome the limitations of traditional methods using ammonium phosphomolybdate for enrichment and analysis. 137 To overcome the drawbacks of Cs precipitation during the process, such as precipitation and easy adsorption onto the solution wall, this study aims to improve the recovery rate of the enrichment analysis process and reduce the difficulty of enrichment analysis.

[0045] The method described in this invention is not limited to the embodiments described in the specific implementation. Other implementation methods derived by those skilled in the art based on the technical solution of this invention also fall within the scope of technical innovation of this invention.

Claims

1. A large-volume underwater... 137 Cs enrichment and analysis method, the method comprising the following steps: S1. Take a preset large volume water sample and put it into a container. While stirring, add an acid solution to the container to adjust the solution to acidity. The preset large volume water sample has a volume of 50L. S2. While stirring, continue to add a predetermined amount of potassium cobalt ferrocyanide to the container, stir and let stand to generate a product containing... 137 For the precipitation of Cs, the preset amount of potassium cobalt ferrocyanide is 8 grams; S3. Remove the supernatant and then transfer the precipitate into a centrifuge. S4. Place the precipitate from step S3 into a centrifuge and centrifuge to remove moisture; S5. Transfer the precipitate from step S4 to an oven for drying and grinding; S6. The precipitate dried and ground in step S5 is placed into a γ box for further processing. 137 Cs content measurement.

2. A large-volume underwater [method] as described in claim 1 137 The Cs enrichment and analysis method is characterized by: The acid solution in step S1 includes hydrochloric acid and nitric acid.

3. A large-volume underwater [method] as described in claim 2 137 The Cs enrichment and analysis method is characterized by: In step S2, the amount of potassium cobalt ferrocyanide is 1.6g of potassium cobalt ferrocyanide added to every 10L of water sample.

4. A large-volume underwater [method] as described in claim 3 137 The Cs enrichment and analysis method is characterized by: In step S1, the amount of acid solution added to the container is 1 mL of acid solution added to every 10 L of water sample.

5. A large-volume underwater [substance] as described in claim 4 137 The Cs enrichment and analysis method is characterized by: In step S5, the precipitate from step S4 is transferred to an oven and dried at 110°C, and then ground.

6. A large-volume underwater [substance] as described in claim 5 137 The Cs enrichment and analysis method is characterized by: The centrifugation device in step S3 is a centrifuge bottle.

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