Device and method for rapidly measuring radon transmission rate of water-gas interface

Abstract

The invention discloses a device and a method for rapidly measuring radon transmission rate of a water-gas interface. The device comprises a static floating chamber, a gas inlet pipe, a gas outlet pipe, a foam plate, a drying bottle and an RAD7 radon measuring instrument, the foam board is arranged around the static floating chamber, the air inlet pipe and the air outlet pipe are respectively installed on the static floating chamber, and the drying bottle, the RAD7 radon measuring instrument and the static floating chamber are sequentially connected through hoses. The device for rapidly measuring the radon transmission rate of the water-gas interface is compact in design, simple in structure, convenient to operate and short in measurement time. A calculation formula between the radon concentration in the water and the radon transmission rate of the water-gas interface is established, and the rate of radon in the air entering the water surface and the rate of radon in the water entering the air are calculated according to measurement data of the RAD7 radon measurement instrument. The method is simple in calculation process, accurate in result, good in environmental adaptability and high in anti-interference performance, the radon transmission rate can be continuously monitored and recorded in real time, and rich data support is provided for research on dynamic behaviors of radon.

Description

Technical Field

[0001] The present invention relates to nuclear radiation detection technology, in particular to a device and method for rapidly measuring the radon transmission rate at the water-air interface. Background Art

[0002] In the fields of environmental science and radioactive pollution monitoring, the transmission and diffusion of radon gas have always been the focus of research. Radon is a natural radioactive gas, mainly originating from the decay products of uranium and thorium in soil, rock, and water. Due to its radioactive hazards, the monitoring and control of radon are crucial for protecting human health and environmental safety. Especially in the water environment, the process of radon gas escaping from the water-air interface into the atmosphere makes a non-negligible contribution to the environmental radon concentration. However, there are many challenges in the current measurement methods for the radon transmission rate at the water-air interface.

[0003] In recent years, with the development of sensor technology and automated monitoring technology, new possibilities have been provided to solve this problem. High-sensitivity radon detection sensors, real-time data acquisition systems, and advanced computational models have made it possible to rapidly measure the radon transmission rate at the water-air interface. By precisely controlling the measurement environment and combining efficient gas collection and analysis techniques, rapid and accurate measurement of the radon transmission rate can be achieved. Such a device and method can not only improve the monitoring efficiency but also provide more accurate data support for environmental science research, helping to better understand and predict the transmission behavior of radon at the water-air interface, thereby providing a scientific basis for formulating effective environmental protection strategies.

[0004] Traditional radon measurement techniques mostly focus on the detection of indoor radon concentration. For the measurement of the radon transmission rate at the water-air interface, due to its dynamicity and complexity, there is a lack of effective direct measurement means. Existing methods often require complex equipment and a long measurement time, and it is difficult to achieve rapid and accurate on-site monitoring. Therefore, developing a device and method that can rapidly and accurately measure the radon transmission rate at the water-air interface has important scientific significance and practical application value for environmental monitoring and radioactive pollution control. Summary of the Invention

[0005] The object of the present invention is to overcome the above deficiencies of the prior art and provide a device and method for rapidly measuring the radon transmission rate at the water-air interface.

[0006] The technical solution of the present invention is: a device for quickly measuring the radon transfer rate at the water-air interface, including a static floating chamber, an intake pipe, an exhaust pipe, a foam board, a drying bottle, and a RAD7 radon detector; the foam board is arranged around the static floating chamber and fixedly connected to the static floating chamber, and a substance for drying gas is placed in the drying bottle; the intake pipe and the exhaust pipe are respectively installed on the static floating chamber, the exhaust pipe is connected to the intake end of the drying bottle through a hose, the exhaust end of the drying bottle is connected to the intake end of the RAD7 radon detector through a hose, and the exhaust end of the RAD7 radon detector is connected to the intake pipe of the static floating chamber through a hose.

[0007] A further technical solution of the present invention is: the substance placed in the drying bottle is calcium chloride powder.

[0008] Another technical solution provided by the present invention is: a method applied to the device for quickly measuring the radon transfer rate at the water-air interface, including a measurement process and a calculation process, and the specific steps are as follows. I. Measurement process Place the static floating chamber and the surrounding foam board on the water surface of the water sample to be measured, start the pump of the RAD7 radon detector, and the radon-containing air in the static floating chamber enters the drying bottle through the exhaust pipe under the action of the pump for drying, and then enters the RAD7 radon detector; record a set of radon concentration data measured by the RAD7 radon detector at regular intervals until the system reaches equilibrium, that is, the radon concentration measured in the RAD7 radon detector reaches equilibrium.

[0009] II. Calculation process The radon in water mainly comes from the decay of dissolved radium in water. The release of radon in water to the air through the water-air interface is the precipitation of radon on the water surface. Since the water volume is approximately infinite during the measurement process, assuming that the radon concentration in water remains unchanged when measuring the radon precipitation rate on the water surface, the radon concentration in the static floating chamber is expressed by formula (1) at this time: (1) Wherein, c(t) represents the radon concentration in the static floating chamber 1, with the unit of Bq / m 3 ; A 1 represents the rate of radon in the air entering the water surface, with the unit of m / s; A 2 represents the rate of radon on the water surface entering the air, with the unit of m / s; c(H 2 o) represents the radon concentration in water, with the unit of Bq / m 3 ; V represents the gas path volume, including the volume of the gas path in the static floating chamber, the volume of the measurement chamber in the RAD7 radon detector 6, and the volume of the connecting pipe, with the unit of m 3 ;S represents the surface area of the static floating chamber, in m 2 ; λ represents the radon decay constant, λ l represents the leakage coefficient.

[0010] Let the effective decay constant of radon λ e be: (2) When the surface area of the static floating chamber is very large and the height is very low, S*A 1 / V is much greater than λ and λ l , at this time, formula (2) is transformed into: (3) Since the RAD7 radon detector cannot directly measure the radon concentration, but measures the concentration of radon daughter Po-218 in the internal measurement chamber of the RAD7 radon detector, it is necessary to perform non-linear fitting through the concentration calculation expression of radon daughter Po-218 in the internal measurement chamber of the RAD7 radon detector to obtain the effective decay constant of radon λ e , and the fitting expression is as follows: (4) where, c po (t) represents the concentration of Po-218 in the measurement chamber of the RAD7 radon detector, in Bq / m 3 ; λ po represents the decay constant of Po-218; J represents the radon exhalation rate of the water surface, in Bq / (m 2 s); Substitute the obtained effective decay constant of radon λ e into formula (3) to calculate the rate A 1 at which radon in the air enters the water surface.

[0011] According to the distribution ratio of gas radon concentration to water radon concentration being A 2 / A 1 , that is, the ratio of gas radon to water radon under equilibrium conditions, it is expressed by the following formula: (5) where, TDenote the temperature during measurement. The rate at which radon in the air enters the water surface obtained from Equation (3) A 1 is substituted into the above Equation (5) to calculate the rate at which radon in the water enters the air A 2 value.

[0012] The present invention has the following advantages compared with the prior art: 1. The device for rapidly measuring the radon transfer rate at the water-air interface provided by the present invention is compact in design, simple in structure, convenient to operate, and short in measurement time.

[0013] 2. The method for rapidly measuring the radon transfer rate at the water-air interface provided by the present invention has a simple calculation process, accurate calculation results, can complete the measurement in a short time, and greatly improves the monitoring efficiency; the measurement method can accurately detect the change in radon concentration at low concentrations, ensuring the reliability of the measurement results. In addition, the present invention also has good environmental adaptability, can work stably under different water body conditions and meteorological conditions, effectively reduces the interference of external factors on the measurement results, and can realize the continuous monitoring function, record the change of the radon transfer rate in real time, and provides rich data support for studying the dynamic behavior of radon.

[0014] The following further describes the detailed structure of the present invention in conjunction with the accompanying drawings and specific embodiments. Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of a device for rapidly measuring the radon transfer rate at the water-air interface; Figure 2 is a top view of the static floating chamber. Specific Embodiments

[0016] Example 1. As Figure 1-2 shown, a device for rapidly measuring the radon transfer rate at the water-air interface includes a static floating chamber 1, an intake pipe 2, an exhaust pipe 3, a foam board 4, a drying bottle 5, and a RAD7 radon detector 6. The foam board 4 is arranged around the static floating chamber 1 and fixedly connected to the static floating chamber 1, enabling the static floating chamber 1 to float on the water surface to be measured. A substance for drying gas, such as calcium chloride powder, etc., is placed in the drying bottle 5. The intake pipe 2 and the exhaust pipe 3 are respectively installed on the static floating chamber 1. The exhaust pipe 3 is connected to the intake end of the drying bottle 5 through a hose. The exhaust end of the drying bottle 5 is connected to the intake end of the RAD7 radon detector 6 through a hose. The exhaust end of the RAD7 radon detector 6 is connected to the intake pipe 2 of the static floating chamber 1 through a hose.

[0017] Example 2. A method applied to the device for rapidly measuring the radon transfer rate at the water-air interface in Example 1 includes a measurement process and a calculation process, and the specific steps are as follows: I. Measurement Process Place the static floating chamber 1 and the surrounding foam board 4 on the water surface of the water sample 7 to be measured. Start the pump of the RAD7 radon detector 6. The radon-containing air in the static floating chamber 1 enters the drying bottle 5 through the air outlet pipe 3 under the action of the pump for drying, and then enters the RAD7 radon detector 6. At regular intervals, in this embodiment, every 10 minutes, record a set of radon concentration data measured by the RAD7 radon detector 6 until the system reaches equilibrium, that is, the radon concentration measured in the RAD7 radon detector 6 reaches equilibrium.

[0018] II. Calculation Process The radon in water mainly comes from the decay of dissolved radium in water. The radon in water is released into the air through the water-air interface, which is the precipitation of radon on the water surface. Since the water volume is approximately infinite during the measurement process, assuming that the radon concentration in water remains unchanged when measuring the radon precipitation rate on the water surface, the radon concentration in the static floating chamber 1 is expressed by formula (1): (1) Wherein, c(t) represents the radon concentration in the static floating chamber 1, with the unit of Bq / m 3 ; A 1 represents the rate of radon in the air entering the water surface, with the unit of m / s; A 2 represents the rate of radon on the water surface entering the air, with the unit of m / s; c(H 2 o) represents the radon concentration in water, with the unit of Bq / m 3 ; V represents the volume of the gas path, including the volume of the gas path in the static floating chamber 1, the volume of the measurement chamber in the RAD7 radon detector 6 and the volume of the connecting pipeline, with the unit of m 3 ; S represents the surface area of the static floating chamber 1, with the unit of m 2 ; λ represents the radon decay constant, λ l represents the leakage coefficient.

[0019] Let the effective decay constant of radon λ e be:[[]] (2) When the surface area of the static floating chamber 1 is very large and the height is very low, S*A 1 / V is much larger than λ and λ l At this time, formula (2) is transformed into:[[]] (3) Since the RAD7 radon detector 6 cannot directly measure the radon concentration, but measures the concentration of radon daughter Po-218 in the internal measurement cavity of the RAD7 radon detector 6. Therefore, it is necessary to perform non-linear fitting through the concentration calculation expression of radon daughter Po-218 in the internal measurement cavity of the RAD7 radon detector 6 to obtain the effective decay constant of radon λ e , and the fitting expression is as follows: (4) Wherein, c po (t) represents the concentration of Po-218 in the measurement cavity of the RAD7 radon detector 6, with the unit of Bq / m 3 ; λ po represents the decay constant of Po-218; J represents the radon exhalation rate of the water surface, with the unit of Bq / (m 2 s). Substitute the obtained effective decay constant of radon λ e into formula (3) to calculate the rate A 1 at which radon in the air enters the water surface

[0020] According to the literature, the distribution ratio A 2 / A 1 of the gas radon concentration to the water radon concentration can be known, that is, the ratio of gas radon to water radon in the equilibrium state, which is expressed by the following formula: (5) Wherein, T represents the temperature during measurement, which can be obtained through sensors, etc. Substitute the rate A 1 at which radon in the air enters the water surface obtained from formula (3) into the above formula (5) to calculate the rate A 2 at which radon in the water enters the air

Claims

1. An apparatus for rapidly measuring the radon transport rate at the water-air interface, characterized in that: It includes a static floating chamber, an intake pipe, an outlet pipe, a foam board, a drying bottle and a RAD7 radon detector; the foam board is arranged around the static floating chamber and fixedly connected to the static floating chamber, and a substance for drying gas is placed in the drying bottle; the intake pipe and the outlet pipe are respectively installed on the static floating chamber, the outlet pipe is connected to the intake end of the drying bottle through a hose, the outlet end of the drying bottle is connected to the intake end of the RAD7 radon detector through a hose, and the outlet end of the RAD7 radon detector is connected to the intake pipe of the static floating chamber through a hose.

2. The device for rapidly measuring the radon transport rate at the water-air interface according to claim 1, characterized in that: The substance placed in the drying bottle is calcium chloride powder.

3. A method applied to the device for rapidly measuring the radon transport rate at the water-air interface according to claim 1 or 2, characterized in that: It includes a measurement process and a calculation process, and the specific steps are as follows. I. Measurement process Place the static floating chamber and the surrounding foam board on the water surface of the water sample to be measured, start the pump of the RAD7 radon detector, and the radon-containing air in the static floating chamber enters the drying bottle through the outlet pipe under the action of the pump for drying, and then enters the RAD7 radon detector; record a set of radon concentration data measured by the RAD7 radon detector at regular intervals until the system reaches equilibrium, that is, the radon concentration measured in the RAD7 radon detector reaches equilibrium. II. Calculation process The radon in water mainly comes from the decay of radium dissolved in water. The radon in water is released into the air through the water-air interface, which is the precipitation of radon on the water surface. Since the water volume is approximately infinite during the measurement process, assuming that the radon concentration in water remains unchanged when measuring the radon precipitation rate on the water surface, the radon concentration in the static floating chamber is represented by formula (1) at this time: （1） Among them, c(t) represents the radon concentration in the static floating chamber 1, in units of Bq / m 3 ; A 1 represents the rate at which radon in the air enters the water surface, in units of m / s; A 2 represents the rate at which radon in the water surface enters the air, in units of m / s; c(H 2 o) represents the radon concentration in the water, in units of Bq / m 3 ; V represents the volume of the gas path, including the volume of the gas path in the static floating chamber, the volume of the measurement chamber in the RAD7 radon detector 6, and the volume of the connecting pipe, in units of m 3 ; S represents the surface area of the static floating chamber, in units of m 2 ; λ represents the radon decay constant, λ l represents the leakage coefficient; Let the effective decay constant of radon λ e be （2） When the surface area of the static floating chamber is very large and the height is very low, S*A 1 / V much larger than λ and λ l , at this time, formula (2) is transformed into: （3） Since the RAD7 radon detector cannot directly measure the radon concentration, but measures the concentration of the radon daughter Po-218 in the internal measurement cavity of the RAD7 radon detector, it is necessary to perform non-linear fitting through the concentration calculation expression of the radon daughter Po-218 in the internal measurement cavity of the RAD7 radon detector to obtain the effective decay constant of radon λ e , and the fitting expression is as follows: （4） in, c po (t) Indicates the concentration of Po-218 in the measurement chamber of the RAD7 radon detector in Bq / m 3 ; λ po represents the decay constant of Po-218; J represents the radon exhalation rate on the water surface, in Bq / (m 2 s); the effective decay constant of radon obtained by fitting λ e Substituting into formula (3), we can calculate the rate at which radon in the air enters the water surface: A 1 The value of According to the distribution ratio of the gas radon concentration to the water radon concentration being A 2 / A 1 , that is, the ratio of gas radon to water radon under the equilibrium state, is expressed by the following formula: （5） Among them, T represents the temperature during measurement, and the rate at which radon in the air enters the water surface obtained from formula (3) A 1 is substituted into the above formula (5) to calculate the rate at which radon in the water enters the air A 2 value.

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