EGU22-13477, updated on 28 Mar 2022
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Residence time of groundwater in porous aquifers by estimating Ra retardation factor

Alessandra Briganti1, Mario Voltaggio1, Paola Tuccimei2, and Michele Soligo2
Alessandra Briganti et al.
  • 1National Research Council (CNR), Institute of Environmental Geology and Geoengineering (IGAG Montelibretti), Monterotondo, Rome, Italy (
  • 2Science Department, Roma Tre University, Rome, Italy

Groundwater age can differ when determined by radioactive tracers due to different retardation factors. According to Krishnawami et al. 1982, Radon isotopes supply to groundwater is considered as a measure of the supply of Radium isotopes. This assumption considerably affects the estimation of the Ra retardation factor. Briganti et al. 2020 reports how the different groundwater supply mechanisms of Ra and Rn should be considered in order to avoid a relevant variation between the real water residence time and the age calculated. In the same work an alternative method for estimating Ra retardation factor is proposed without using Rn data as a comparison term. A synthesis of the main results of laboratory tests is presented in order to describe possible applications of the method.


Briganti A., Voltaggio M., Tuccimei P. & Soligo M. 2020. Radium in groundwater hosted in porous aquifers: estimation of retardation factor and recoil rate constant by using NAPLs. SN Appl. Sci. 2, 1934 (2020).

Krishnaswami S., Graustein W.S., Turekian K.K., Dowd J.F. 1982. Radium, thorium and radioactive lead isotopes in groundwaters: application to the in situ determination of adsorption-desorption rate constants and retardation factors. Water Resour. Res. 18:1633–1675.

How to cite: Briganti, A., Voltaggio, M., Tuccimei, P., and Soligo, M.: Residence time of groundwater in porous aquifers by estimating Ra retardation factor, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13477,, 2022.


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