Determination of the radon transfer velocity coefficient in water under static and turbulent conditions

The risk associated with the inhalation of radon gas has prompted numerous studies analyzing its behavior and transport from its generating source (soil, water or building materials) to its accumulation in enclosed spaces. In this research, the process of radon gas release from water to air in hermetically sealed equipment and under controlled conditions at laboratory scale is analyzed. The experimental measurements have been later processed and analyzed by an iterative algorithm, based on the minimization of the squared error, to develop a dynamic model through which the transfer velocity coefficient (k) is obtained in different test conditions. From the experimental results and the dynamic model a coefficient of (1.4 ± 0.14)·10−3 m h−1 is obtained for static water conditions and (2.4 ± 0.6)·10−3 m·h−1for turbulent water. It is verified that the escape process of radon gas in water is slower when it is in a static state, without turbulence. Finally, the coefficient is validated by calculating the estimated radon concentration evolution in air, which in turn is compared with the experimental results. •Radon transfer velocity coefficient in water has been determined.•Developed an iterative algorithm that describes radon scape from water to air.•Coefficients and dynamic model have been validated through experimental results.•Radon transfer velocity coefficient is higher for turbulent water conditions.