title: Radon as a naturally occurring tracer for the assessment of residual NAPL contamination of aquifers.
abstract: The noble gas radon has a strong affinity to non-aqueous phase-liquids (NAPLs). That property makes it applicable as naturally occurring partitioning tracer for assessing residual NAPL contamination of aquifers. In a NAPL contaminated aquifer, radon dissolved in the groundwater partitions preferably into the NAPL. The magnitude of the resulting radon deficit in the groundwater depends on the NAPL-specific radon partition coefficient and on the NAPL saturation of the pore space. Hence, if the partition coefficient is known, the NAPL saturation is attainable by determination of the radon deficit. After a concise discussion of theoretical aspects regarding radon partitioning into NAPL, related experimental data and results of a field investigation are presented. Aim of the laboratory experiments was the determination of radon partition coefficients of multi-component NAPLs of environmental concern. The on-site activities were carried out in order to confirm the applicability of the "radon method" under field conditions.
authors.affiliation: UFZ Centre for Environmental Research, Permoserstrasse 15, 04318 Leipzig, Germany. michael.schubert@ufz.de
authors.forename: Michael
authors.initials: M
authors.lastname: Schubert
authors.forename: Albrecht
authors.initials: A
authors.lastname: Paschke
authors.forename: Steffen
authors.initials: S
authors.lastname: Lau
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Geyer
authors.forename: Kay
authors.initials: K
authors.lastname: Knöller
mesh_terms: D004785:Environmental Pollutants / Q000032:analysis; D005618:Fresh Water / Q000032:analysis; D008433:Mathematics; D011849:Radioactive Tracers; D011886:Radon / Q000032:analysis*; D012989:Soil Pollutants; D012995:Solubility; D013816:Thermodynamics; D014873:Water Pollutants / Q000032:analysis
chemical_list: D004785:Environmental Pollutants; D011849:Radioactive Tracers; D012989:Soil Pollutants; D014873:Water Pollutants; D011886:Radon