Study on an on-site radon-in-water measurement system based on degassing membrane

Wang, Yunxiang; Zhang, Lei; Wang, Jingbo; Guo, Qiuju

doi:10.1016/j.radmeas.2019.106231

Cited by 8 publications

(3 citation statements)

References 32 publications

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“…The membrane keeps water and air physically separated, and the unit is not affected by the operational orientation when connected to Rn detector (Schubert et al, 2008). However, turbid waters can clog the membrane relatively quickly; hence contactors generally require relatively clean water with low suspended particulate matter (SPM) concentrations compared to the shower-head Rn extractor which is part of the RAD AQUA system (Wang et al, 2020). To reduce the possibility of suspended particle clogging the extraction module during operation, a pre-filtration device with a 45-mm micro-strainer (Huiante Co., China) is installed at the water inlet of the OUC-Rn system.…”

Section: Ouc-rn System Setupmentioning

confidence: 99%

In-situ radon-in-water detection for high resolution submarine groundwater discharge assessment

Zhao

Burnett

et al. 2022

Front. Mar. Sci.

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Submarine groundwater discharge (SGD), including both land-based fresh groundwater that enters the ocean from coastal aquifers as well as recirculated seawater that is continuously recharged and discharged on the seabed, has been considered as an important component of the global water and biogenic element (e.g., nitrogen, phosphorus, silicon and carbon) sources and a significant pathway for material exchange at the land-sea interface of coastal ecosystems. Some researchers reported that SGD associated nutrient additions to coastal waters have caused unwanted ecological issues, including red tides, coastal acidification and hypoxia. Natural radon isotope (222Rn, t1/2 = 3.8 d) is an excellent tracer for studying SGD and other oceanographic processes including air-sea gas exchange, sediment-water diffusion, and earthquake prediction. However, the conventional radon measurement methods suffer many technical disadvantages. We consequently developed a convenient submersible radon determination approach (“OUC-Rn”) using a commercial pulsed ionization chamber (PIC) radon sensor and gas extraction membrane module to produce high precision and high resolution observations. We demonstrate the radon degassing efficiency of the membrane contactor is comparable to the shower-head type air-water exchanger but is independent of operating position. The radon measurement efficiency of the PIC is 2-fold higher than the RAD7 detector and is far less influenced by moisture. We successfully deployed the system in 2.5 meters water depth over a 100 hours period in an anthropogenic influenced bay. Based on our high temporal resolution observations, the SGD flux was estimated to be 0-43.0 cm/d (mean: 25.4 ± 14.5 cm/d). The SGD fluxes pattern plotted together with the tidal variations revealed that tidal pumping may be the main force driving seawater recirculation into aquifers and thus affecting nutrient, carbon and other dissolved matters dynamics in coastal regions.

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Section: Ouc-rn System Setupmentioning

confidence: 99%

In-situ radon-in-water detection for high resolution submarine groundwater discharge assessment

Zhao

Burnett

et al. 2022

Front. Mar. Sci.

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“…The measuring method includes diffusion, degassing membrane method and the bubbling method. In bubbling method, the balance time of radon-in-water and radon-in-air concentration is shortened by increasing the contact area between water and air with bubbling probe (Wang et al 2020). Therefore, this method has been widely used, and new measurement methods and equipment have been developed, such as an improved version of the ionization chamber, a series of equipment based on bubble chambers and RAD7 monitors (D Lane-Smith.…”

Section: Introductionmentioning

confidence: 99%

Research on the conversion coefficient for measuring radon concentration in water based on bubbling method

Fan

Lin

et al. 2022

Radiation Measurements

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Section: Introductionmentioning

confidence: 99%

Research on the Conversion Coefficient for Measuring Radon Concentration in Water Based on Bubbling Method

Tao

Fan

Lin

et al. 2021

Preprint

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Radon is soluble in water, and the radon in drinking water is one of the sources of indoor radon. The China national standard for drinking water (GB5749-2006) indicates that the radon concentration in drinking water cannot be higher than 300pCi/L. The widely used method for measuring radon concentration in water is to use the RAD7 and the H2O accessory which provided by the Durridge Company for bubbling measurement. There are two kind sample bottles: 40ml and 250ml; the measurement steps: bubbling for 5 minutes, and measuring for 20 minutes. For the 40ml sample volume the conversion coefficient is around 25. For the 250ml sample volume the conversion coefficient is around 4. Since the price of the accessory is more than one thousand dollars, and the drying tube of the accessory is small, it needs to be replaced after each measurement which makes the operation is troublesome. We used a big drying tube to perform the radon concentration in water measurement. A new model for description the radon concentration in the gas circuit is proposed, and the conversion coefficient in any measurement condition is obtained. Any volume of sample bottle and drying tube can be used, selecting the suitable bubbling time and measuring time, the radon concentration in water can be obtained.

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Study on an on-site radon-in-water measurement system based on degassing membrane

Cited by 8 publications

References 32 publications

In-situ radon-in-water detection for high resolution submarine groundwater discharge assessment

In-situ radon-in-water detection for high resolution submarine groundwater discharge assessment

Research on the conversion coefficient for measuring radon concentration in water based on bubbling method

Research on the Conversion Coefficient for Measuring Radon Concentration in Water Based on Bubbling Method

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