Laboratory-scale experimental and modelling investigations of Rn profiles in chemically heterogeneous LNAPL contaminated vadose zones.

The potential of LNAPL delineation by Rn soil-gas monitoring in a chemically heterogeneous vadose zone was investigated in this study based on laboratory (batch and columns) experiments and numerical modelling. An enhanced version of the MIN3P reactive transport code was used to simulate Rn transport in both uncontaminated and NAPL-contaminated vadose zones and results were validated against analytical solutions and laboratory experiments. Results show that Rn activity profiles are mainly controlled by porous media Rn production, vadose zone fluid saturations and especially the type and distribution of NAPL in contaminated areas.