Measuring 222Rn in aquatic environment via Pulsed Ionization Chamber Radon Detector
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Abstract: Radon (Rn) is a naturally occurring radioactive inert gas in nature, and 222Rn has been routinely used as a powerful tracer in various aquatic environmental research on timescales of hours to days, such as submarine groundwater discharge. Here we developed a new approach to measure 222Rn in discrete water samples with a wide range of 222Rn concentrations using a Pulsed Ionization Chamber (PIC) Radon Detector. The sensitivity of the new PIC system is evaluated at 6.06 counts per minute for 1 Bq/L when a 500 mL water sample volume is used. A robust logarithmic correlation between sample volumes, ranging from 250 mL to 5000 mL, and system sensitivity obtained in this study strongly suggests that this approach is suitable for measuring radon concentration levels in various natural waters. Compared to the currently available methods for measuring radon in grab samples, the PIC system is cheaper, easier to operate and does not require extra accessories (e.g., drying tubes etc.) to maintain stable measurements throughout the counting procedure.
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Table 1. Comparison of 222Rn measured by Pulsed Ionization Chamber Radon Detector and RAD7 in groundwater and surface seawater samples collected in the Jiaozhou Bay
Sample Date
(YYYY.MM.DD)Sample bottle
volume/mLPIC/
(Bq·L−1)RAD7/
(Bq·L−1)Groundwater 2021.10.20 250 8.3 ± 0.6 8.5 ± 1.2 2021.10.20 250 8.6 ± 0.8 8.5 ± 1.2 2021.11.17 250 2.3 ± 0.2 1.7 ± 0.6 2021.12.19 250 3.1 ± 0.2 2.7 ± 1.0 Surface seawater 2021.11.17 500 0.30 ± 0.03 0.3 ± 0.1 -
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