P1 Assessing Pollutant Turnover in Rivers by Target, Non-Target, and Toxicity Analysis

People Involved

Principal Investigators

Jun.-Prof. Dr. Christiane Zarfl

University of Tübingen, Environmental Systems Analysis


Dr. Marc Schwientek

University of Tübingen, Hydrogeochemistry

Prof. Dr. Beate Escher

University of Tübingen, Environmental Toxicology & Helmholtz Center for Environmental Research (UFZ), Cell Toxicology

Prof. Dr. Christian Zwiener

University of Tübingen, Environmental Analytical Chemistry


Dr. Martina Werneburg

University of Tübingen, Environmental Analytical Chemistry (until 10/2019)

Maximilian Müller, MSc

Clarissa Glaser, MSc

University of Tübingen, Environmental Systems Analysis

Ran Wei (associated)

University of Tübingen, RTG Hydrosystem Modelling

Research Questions and General Approach

Research Questions

Rivers integrate pollutants’ emissions and processes of the whole catchment. They also receive a broad spectrum of pollutants via direct and indirect inputs. In-stream processes such as sorption to particles, sedimentation, and transformation, both biotic and abiotic, modify pollutant signals. However, toxic effects of mixtures are largely unknown.

Thus the objectives of project P1 “Rivers” are:

  • To distinguish dominant input sources (diffuse vs. point, surface vs. subsurface) for a large set of chemical pollutants and their degradation products in rivers.
  • To quantify transformation processes within studied river channels compared to turnover in other compartments of the catchment
  • To identify important driving factors of natural attenuation processes in different river reaches.
  • To define suitable indicator chemicals or pollutant patterns that can be used as proxies for relevant environmental processes.

General Approach of P1

In the “River” project P1 we combine the following methods to answer the research questions:

  • Lagrangian sampling of river segments of contrasting characteristics
  • Non-target screening with high resolution mass spectrometry (HRMS) to detect pollutant patterns and transformation products
  • Cell-based bioassays for different modes of toxic action as risk-scaled sum parameters of mixtures of pollutants
  • Mass-balance models using chemical and bioanalytical equivalent concentrations (BEQ)


Combining chemical and toxicological analysis to assess water quality in the Ammer River and its tributaries
Quantification of groundwater exfiltration into the Ammer River

Quantification of micropollutants’ net attenuation in different reaches of the Ammer River
Analyzing micropollutant and toxicological effect dynamics during a rain event
Investigating particle-associated pollutant dynamics during a rain event
Modelling sediment and pollutant loads according to different general source areas



Glaser C., Schwientek M., Junginger T., Gilfedder B. S., Frei S., Werneburg M., Zwiener C., Zarfl C. (2020): Comparison of environmental tracers including organic micropollutants as groundwater exfiltration indicators into a small river of a karstic catchment. Hydrological Processes (revised)

Müller, M.E., Zwiener, C., Escher, B.I. (2020): Storm event-driven occurrence and transport of dissolved and sorbed organic micropollutants and associated effects in a river. Environ. Toxicol. Chem. (submitted)


Glaser C., Zarfl C., Werneburg M., Böckmann M., Zwiener C., Schwientek M. (2020): Temporal and spatial variable in-stream attenuation of selected pharmaceuticals. Sci. Total Environ. 741, 139514, doi: https://doi.org/10.1016/j.scitotenv.2020.139514.

Glaser C., Zarfl C., Rügner H., Lewis A., Schwientek M. (2020): Analysing particle-associated pollutant transport to identify in-stream sediment processes during a high flow event. Water 12(1794), 1-16, doi: https://doi.org/10.3390/w12061794.

Müller M.E., Werneburg M., Glaser C., Schwientek M., Zarfl C., Escher B. I., Zwiener C. (2020): Influence of emission sources and tributaries on the spatial and temporal patterns of micropollutant mixtures and associated effects in a small river. Environ. Toxicol. Chem. 39(7), 1382-1391, doi: https://doi.org/10.1002/etc.4726.

Glaser C., Schwientek M., Zarfl C. (2019): Designing field-based investigations of organic micropollutant fate in rivers. Environ. Sci. Pollut. Res. 28, 28633-28649, doi: https://doi.org/10.1007/s11356-019-06058-1.

Guillet, G., Knapp, J.L.A., Merel,S., Cirpka, O.A., Grathwohl, P., Zwiener, C., Schwientek, M. (2019): Fate of wastewater contaminants in rivers: Using conservative-tracer based transfer functions to assess reactive transport. Science of the Total Environment 656: 1250-1260, doi: 10.1016/j.scitotenv.2018.11.379.

Liu Y., Zarfl C., Basu N., Cirpka O.A. (2019): Turnover and legacy of sediment-associated PAH in a baseflow-dominated river. Sci. Total Environ. 671, 754-764, doi: https://doi.org/10.1016/j.scitotenv.2019.03.236.

Müller, M.E., Vikstrom, S., König, M., Schlichting, R., Zarfl, C., Zwiener, C., Escher, B.I. (2019): Mitochondrial toxicity of selected micropollutants, their mixtures and surface water samples measured by the oxygen consumption rate in cells. Environmental Toxicology and Chemistry 38(5), 1000-1011, doi: https://doi.org/10.1002/etc.4396.

Liu Y., Zarfl C., Basu N., Schwientek M., Cirpka O.A. (2018): Contributions of catchment and in-stream processes to suspended sediment transport in a dominantly groundwater-fed catchment. Hydrol. Earth Syst. Sc. 22, 3903-3921, doi: https://doi.org/10.5194/hess-22-3903-2018.

Müller M.E., Escher B.I., Schwientek M., Werneburg M., Zarfl C., Zwiener C. (2018): Combining in vitro reporter gene bioassays with chemical analysis to assess changes in the water quality along the Ammer River, Southwestern Germany. Environ. Sci. Europe 30(1), 20, doi: https://doi.org/10.1186/s12302-018-0148-y.

Schwientek, M., Rügner, H., Scherer U., Rode M., Grathwohl P. (2017): A parsimonious approach to estimate PAH concentrations in river sediments of anthropogenically impacted watersheds. Science of the Total Environm. 601-602: 636-645, doi:10.1016/j.scitotenv.2017.05.208.

BSc and MSc Theses

BSc Theses

Sarah Hanus (2017/2018): Transverse mixing of the Neckar River downstream of the confluence with the Ammer River

Eva Voggenreiter (2018): Estimating groundwater inflow in the Ammer River using geochemical tracers

Lorenz Krüger (2019): Modelling micropollutants in the Ammer River

Matthias Böckmann (2019): Fate of organic micropllutants in the Ammer River - A modelling approach

Niklas Best (2019): Räumliche Verteilung und Dynamik von Pestiziden in Fließgewässern des Ammer-Einzugsgebiets

Rosa Degenhardt (2019/2020): Linking in-vitro effects and micropollutant concentrations in the Ammer Catchment through mixture toxicity modelling

MSc Theses

Michaela Löffler (2016/2017): Natural and anthropogenic Influences on the microbial community composition in the River Ammer (Tübingen, Germany)

Andrea Schübel (2017): Influence of wastewater treatment plant effluents on the bacterial community composition in river sediments

Tobias Junginger (2019): Determination and quantification of groundwater inflow in a complex river system