EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Occurrence and Distribution of PFAS in the River and Groundwater at Two Danube Sites 

Ali AA Obeid1,2, Thomas James Oudega1,2, Ottavia Zoboli3, Claudia Gundacker4, Alfred Paul Blaschke1,2, Matthias Zessner3,2, Ernis Saracevic3, Nicolas Devau5, Margaret E. Stevenson1,2, Nikola Krlovic3, Meiqi Liu3, Zsuzsanna Nagy-Kovács6, Balázs László6, Gerhard Lindner1,2, and Julia Derx1,2
Ali AA Obeid et al.
  • 1Institute of Hydraulic Engineering and Water Resources Management, TU Wien, Austria
  • 2Interuniversity Cooperation Centre for Water and Health (ICC Water & Health),
  • 3Institute for Water Quality and Resource Management, TU Wien, Austria
  • 4Institute of Medical Genetics, Medical University of Vienna, Austria
  • 5BRGM, French Geological Survey, 3 Av. Claude Guillemin, B.P. 6009, F-45000 Orléans, France
  • 6Budapest Waterworks Ltd, Váci út 23-27, 1134 Budapast, Hungary

Per- and Polyfluoroalkyl Substances (PFAS) are chemicals used for many domestic and industrial purposes related to their physicochemical properties. However, those same properties make them mobile and persistent in the environment, and on top of that, they are toxic and can affect human health in the short and long term, as they are bio-accumulative. Many processes govern the transport of PFAS in the surface waters and groundwater, e.g., sorption, biodegradation, co-transport, and transformation. Monitoring PFAS at different locations can help understand these processes and provide datasets to calibrate and validate reactive transport models simulating PFAS fate and transport. This study compares PFAS presence and distribution in river water and groundwater at two Danube river sites. One site is characterized by a steady water level in the river and natural flow from the river to the groundwater, with a clogging layer at the aquifer-river interface. In contrast, the other site has a more dynamic water level in the river, several pumping wells affecting water infiltration rates, and lacks a clogging layer.

Samples were collected monthly for 12 months at the static study site and 8 months at the dynamic study site. Targeted analysis for 32 PFAS compounds has been carried out using liquid chromatography mass spectrometry (LCMS). The concentrations of the compounds were generally less than 20 ng/l, and most of the compounds were lower than the limit of quantification/detection. The results show that 3H-perfluoro-3-[(3-methoxypropoxy) propanic acid] (ADONA) had the highest concentration at the two sites, both in the river and groundwater. The longer chain PFAS exhibited a slight reduction in concentration from the river towards groundwater due to, most likely, sorption, while the shorter chain did not. The 6:2 FTS precursor was detected in the river but not in the groundwater. For some substances, the concentrations were higher in the groundwater compared to the river, indicating either background water influence, a transformation of PFAS, different transport routes (e.g., accumulation over time), or longer flow paths. Longer chain lengths, greater than 9 carbon atoms, were never detected above the limit of quantification in the river and groundwater. More PFAS compounds were detected at the dynamic study site than at the static one, even though, it is located further downstream, indicating nearby PFAS sources or/and influents along the river course. It is worth mentioning that large wastewater treatment plants are discharging their effluent downstream of the static site, in addition to sewer overflows from large cities in between. The PFAS concentrations in the river and groundwater during one high-flow event showed little difference compared to the ones during basic monthly monitoring at both study sites, however, another high flow event is needed to confirm this observation.

How to cite: Obeid, A. A., Oudega, T. J., Zoboli, O., Gundacker, C., Blaschke, A. P., Zessner, M., Saracevic, E., Devau, N., Stevenson, M. E., Krlovic, N., Liu, M., Nagy-Kovács, Z., László, B., Lindner, G., and Derx, J.: Occurrence and Distribution of PFAS in the River and Groundwater at Two Danube Sites , EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-11264,, 2023.

Supplementary materials

Supplementary material file