CN106198168B - Sample preparation device for measuring strontium-90 in low-salinity water body - Google Patents

Abstract

The invention relates to a sample preparation device for measuring strontium-90 in low-salinity water body, which comprises: a purification component, the purification component includes a water tank and a filter arranged in the water tank; a mixing component, the mixing component includes A water storage tank in communication with the filter, a stirrer installed in the water storage tank, a plurality of dosing devices connected with the water storage tank for adding chemical reagents into it; a filter assembly, the filter assembly It includes a filtrate collector communicated with the water storage tank and a strontium membrane mounted on the filtrate collector. By adopting purification components, mixing components and filtering components with specific structures, and enriching strontium-90 in water through strontium membranes, more samples can be processed in a short period of time, greatly shortening the processing time and process.

Description

A sample preparation device for measuring strontium-90 in low salinity water

technical field

The invention belongs to the field of environmental monitoring, and relates to a sample preparation device, in particular to a sample preparation device for measuring strontium-90 in a low-salinity water body.

Background technique

Strontium-90 (ie, ⁹⁰ Sr) is a fission product of U-235 and Pu-239, mainly derived from nuclear weapons explosions and nuclear reactors. In a nuclear power plant reactor, it may enter the primary circuit of the reactor due to defective or damaged fuel cladding, and is discharged to the environment with the liquid radioactive effluent. Strontium-90 is a pure beta radionuclide with a half-life of 28.8 years, which is a highly toxic nuclide. Among the radioactive strontium isotopes, strontium-90 is the most harmful because of its long physical and biological half-lives (49.3 years) and will Persistently deposited in the hematopoietic skeletal system, replacing calcium and causing radiation sickness (such as leukemia); at the same time, the high-energy b-rays produced by its daughter yttrium-90 (ie, ⁹⁰ Y) can cause severe damage to the bone marrow.

Strontium-90 is the most concerned radionuclide in environmental monitoring and liquid effluent monitoring of nuclear facilities. By monitoring the surrounding environment of nuclear facilities and the activity concentration of strontium-90 in liquid radioactive effluents, we can confirm whether there is any abnormality in the operation of nuclear facilities. emissions, and can be used to assess the possible radiation effects on the public from the discharge of radioactive material from nuclear facilities.

In the prior art, the fuming nitric acid method (GB 6764-86) or the extraction chromatography method (GB 6766-86) are generally used, and the measurement is performed by a proportional counter. These two analysis methods have the characteristics of complicated analysis steps and long analysis time. In order to reduce the cost of analyzing samples, there is a need to develop a fast and inexpensive method for analyzing strontium-90 in water. 3M Company of the United States has launched a solid phase extraction disk (Solid Phase Extraction Disk) for the determination of strontium-90 in groundwater samples. Its operation steps are simple and fast, and it saves chemical reagents. However, the solid phase extraction tablet is only suitable for treating water bodies with high activity concentration of strontium-90, and is not suitable for treating environmental water samples and nuclear facility liquid effluents with low activity concentration of strontium-90.

At present, there is no sample preparation device for the measurement of strontium-90 in water at home and abroad. In order to reduce the cost of analyzing samples, it is necessary to develop a sample preparation device for the measurement of strontium-90 in water, so as to facilitate the analysis of environmental samples and nuclear samples with low salinity. Strontium-90 was measured in liquid effluent samples from the facility.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a sample preparation device for measuring strontium-90 in low salinity water in order to overcome the deficiencies of the prior art.

In order to achieve the above purpose, the technical scheme adopted in the present invention is: a sample preparation device for measuring strontium-90 in a low salinity water body, which comprises:

a purification assembly, the purification assembly includes a water tank and a filter arranged in the water tank;

A mixing assembly comprising a water storage tank in communication with the filter, an agitator installed in the water storage tank, and a plurality of dosing devices in communication with the water storage tank for adding chemical reagents therein ;

The filter assembly includes a filtrate collector communicated with the water storage tank and a strontium membrane installed on the filtrate collector.

Preferably, the purification assembly further includes a microfilter in communication with the filter and an ultrafilter in communication with the microfilter.

Further, the microfilter and the filter are connected by a booster pump.

Further, the mixing assembly also includes an adapter connected with each of the dosing devices, a peristaltic pump connected between the adapter and the water storage tank, and a peristaltic pump connected with the water storage tank and connected with the peristaltic pump. The first three-way valve communicated with the filtrate collector.

Further, the filter assembly also includes a suction filtration pump connected with the filtrate collector, a first two-way valve connected with the water storage tank and the filtrate collector, and a first two-way valve connected with the filtrate collector for The second 2-way valve that controls its outflow.

Further, the mixing assembly also includes a second three-way valve connected with the water storage tank and the ultrafilter, and a third two-way valve installed between the second three-way valve and the water storage tank valve; the purification assembly further includes a third three-way valve that is connected to the booster pump and the microfilter and is connected to the second three-way valve; A liquid level controller in which a three-way valve, a second three-way valve, the third three-way valve and the booster pump are electrically connected.

Further, a pressure sensor is installed on the pipeline between the second three-way valve and the third two-way valve.

Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art: the sample preparation device for the measurement of strontium-90 in low-salinity water bodies of the present invention adopts specific structures of purification components, mixing components and filtering components, and through The strontium membrane can enrich the strontium-90 in the water body, so that more samples can be processed in a short time, and the processing time and process can be greatly shortened.

Description of drawings

1 is a schematic structural diagram of a sample preparation device for measuring strontium-90 in a low-salinity water body according to the present invention;

Among them, 1, purification component; 11, water tank; 12, filter; 14, microfilter; 15, ultrafilter; 16, third three-way valve; 2, mixing component; 21, water storage tank; 22, agitator; 23, the third two-way valve; 24, the first three-way valve; 25, the peristaltic pump; 26, the adapter; 27, the dosing device; 28, the pressure sensor; 29, the second three-way valve; 3, the filter assembly; 31, filtrate collector; 32, suction filter pump; 33, first two-way valve; 34, second two-way valve; 35, strontium diaphragm.

Detailed ways

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in Figure 1, the sample preparation device for measuring strontium-90 in low salinity water body mainly includes a purification component 1, a mixing component 2 and a filtering component 3.

The purification assembly 1 includes a water tank 11 and a filter 12 arranged in the water tank 11 . The mixing assembly 2 includes a water storage tank 21 in communication with the filter 12 , a stirrer 22 installed in the water storage tank 21 , and a plurality of dosing devices 27 in communication with the water storage tank 21 for adding chemical reagents thereto. The filter assembly 3 includes a filtrate collector 31 communicated with the water storage tank 21 and a strontium membrane 35 (ie, a strontium solid phase extraction membrane for extracting strontium-90 in water) mounted on the filtrate collector 31 .

In this embodiment, in order to optimize the performance of the sample preparation device, the purification assembly 1 further includes a microfilter 14 communicated with the filter 12 and an ultrafilter 15 communicated with the microfilter 14, so that the water body can be effectively removed. Impurities make up for the defect that the prior art cannot handle a large number of water samples. The microfilter 14 and the filter 12 are connected by a booster pump 13 . The mixing assembly 2 also includes an adapter 26 connected with each dosing device 27, a peristaltic pump 25 connected between the adapter 26 and the water storage tank 21, and a peristaltic pump 25 connected with the water storage tank 21 and communicated with the filtrate collector 31. The first three-way valve 24 can be added to the water storage tank 21 or the filtrate collector 31 as required (in this embodiment, there are three dosing devices 27, respectively containing concentrated nitric acid, methanol and 2 mol/L nitric acid). The filter assembly 3 also includes a suction filtration pump 32 connected with the filtrate collector 31, a first two-way valve 33 connected with the water storage tank 21 and the filtrate collector 31, and a filter connected with the filtrate collector 31 for controlling the output of the filtrate. The second two-way valve 34 can speed up the speed of the water body passing through the strontium diaphragm 35, and can control the on-off of the first two-way valve 33 and the second two-way valve 34 as required.

In this embodiment, the mixing assembly 2 further includes a second three-way valve 29 connected with the water storage tank 21 and the ultrafilter 15 and a third two-way valve installed between the second three-way valve 29 and the water storage tank 21 23; The purification assembly 1 also includes a third three-way valve 16 connected to the booster pump 13 and the microfilter 14 and connected to the second three-way valve 29; in this way, by introducing pure water into the water tank 11, the third three-way valve is passed through the third three-way valve. 16. The second three-way valve 29 directly enters the water storage tank 21 to realize the reverse cleaning of the sample preparation device, thereby ensuring the durability of the sample preparation device and each sample measurement will not be disturbed by the previous sample. The water storage tank 21 is also provided with a liquid level controller 20 respectively connected to the third two-way valve 23, the second three-way valve 29, the third three-way valve 16 and the booster pump 13, the second three-way valve 29 and the booster pump 13. A pressure sensor 28 is installed on the pipeline between the third two-way valve 23, which improves the automation of the sample preparation device, and can measure strontium-90 in low-salinity environmental water bodies and liquid effluents of nuclear facilities, so that most water bodies can be treated ; If it is measured with a liquid scintillation spectrometer, it can reach a low enough detection limit to meet the detection limit requirements of strontium-90 measurement in environmental water samples.

The above-mentioned embodiments are only intended to illustrate the technical concept and characteristics of the present invention, and the purpose thereof is to enable those who are familiar with the art to understand the content of the present invention and implement them accordingly, and cannot limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included within the protection scope of the present invention.

Claims (1)

1. A sample preparation device for measuring strontium-90 in a low-salinity water body, characterized in that it comprises: a purification assembly (1), the purification assembly (1) comprising a water tank (11), which is arranged in the water tank (1). The filter (12) in 11), the microfilter (14) in communication with the filter (12), and the ultrafilter (15) in communication with the microfilter (14); A mixing assembly (2), the mixing assembly (2) comprising a water storage tank (21) communicated with the filter (12), a stirrer (22) installed in the water storage tank (21), and a water storage tank (22) The water storage tank (21) is communicated with a plurality of dosing devices (27) for adding chemical reagents into it; A filter assembly (3), the filter assembly (3) comprising a filtrate collector (31) communicated with the water storage tank (21) and a strontium membrane (35) mounted on the filtrate collector (31) , the strontium membrane (35) is used to extract strontium-90 in water; The microfilter (14) and the filter (12) are connected through a booster pump (13); the mixing assembly (2) further comprises a rotary pump connected to each of the dosing devices (27). A joint (26), a peristaltic pump (25) connecting the adapter (26) and the water storage tank (21), and connecting the peristaltic pump (25) with the water storage tank (21) and with the filtrate A first three-way valve (24) connected to the collector (31); the filter assembly (3) further includes a suction filter pump (32) connected to the filtrate collector (31), and connected to the water storage tank (21) and the first two-way valve (33) of the filtrate collector (31) and the second two-way valve (34) connected with the filtrate collector (31) for controlling its liquid outlet; The mixing assembly (2) further comprises a second three-way valve (29) connected with the water storage tank (21) and the ultrafilter (15), and a second three-way valve (29) installed on the second three-way valve (29) and the ultrafilter (15). A third two-way valve (23) between the water storage tanks (21); the purification assembly (1) further comprises a connection between the booster pump (13) and the microfilter (14) and with the first A third three-way valve (16) connected to the two-three-way valve (29); the water storage tank (21) is also provided with the third two-way valve (23) and the second three-way valve (29), respectively. ), the third three-way valve (16) and the booster pump (13) are electrically connected to the liquid level controller (20); the second three-way valve (29) and the third two-way A pressure sensor (28) is installed on the pipeline between the valves (23); Pure water is introduced into the water tank (11), and enters the water storage tank (21) through the third three-way valve (16) and the second three-way valve (29) to realize the Backwashing of the sample preparation device.

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