We are looking for a highly motivated, creative, and well-qualified young scientist for a 3-year PhD position to join our INTERREG-funded transnational research project ReactiveCity, focusing on the transport and transformation of urban micropollutants and associated risks in aquatic ecosystems.

Context

The cities of the Upper Rhine are gradually adopting adaptation plans to mitigate the effects of climate change and improve urban sustainability in line with the One Health approach. Concepts like the sponge city and the permeable city, are in sustainable urban water management and rely on the reuse of rainwater and treated wastewater, increased stormwater retention after rainfall events, and improved surface permeability for reducing run-off in favour of aquifer recharge. These measures make it possible to increase both water supply (Luthy et al., 2019) and to limit the discharge of potentially polluted runoff into surface water bodies (Zhang et al., 2020).

However, these waters are often contaminated by micropollutants (Wiest et al., 2021; Finckh et al., 2024) which can have adverse environmental effects even at very low concentrations (Bollmann et al., 2014; Challis et al., 2021; Mutzner et al., 2023). Therefore, a sustainable urban water management must go hand in hand with a reduction and further elimination of micropollutants, specifically pharmaceutical residues and biocides who make up the most significant fraction of micropollutants in urban storm- and wastewater (Zhang et al., 2024).

However, characterising micropollutants in the urban aquatic environment remains a major challenge, due to pronounced temporal and spatial variability of both water budget and contaminant concentrations which are dependent on many variables such as hydro-climatic events (Goorè Bi et al., 2015) and land use characteristics (Mutzner et al., 2022). 

ReactiveCity envisions a biocide-free city and aims to develop generic tools for a spatialised assessment of emission zones and flows of urban biocides and the effectiveness of alternatives as well as monitoring flows of urban biocides and assessing their ecotoxicological impact. ReactiveCity pursues a holistic approach, bringing together a wide range of disciplines and stakeholders, including citizens, city authorities and water managers.

Project and Partners

The PhD thesis is part of the ReactiveCity project (https://fered.unistra.fr/recherches/projets/reactivecity) and will be conducted within the Institute of Earth and Environment of Strasbourg (ITES-UMR 7063; https://ites.unistra.fr/) at the University of Strasbourg (https://www.unistra.fr/) over a duration of three years. ReactiveCity is a cross-border research project in partnership with the universities and cities of Freiburg and Landau and is co-funded by the European Union under the INTERREG VI Upper Rhine programme (https://www.interreg-rhin-sup.eu/projet/reactivecity-une-ville-pro-active-sans-biocides/).

The PhD project 

The PhD project will evolve around the following key questions:

(i) What is the potential and what are the limitations of applying multi-element compound-specific isotope analysis (ME-CSIA) to urban micropollutants and their transformation products in order to monitor their transformation and persistence on an urban scale?

(ii) How can selected biocides and their transformation products in urban aquatic environments (stormwater basins, wastewater discharge etc.) be monitored in situ?

(iii) How can in situ diagnostic data be combined with transformation kinetics and isotopic fractionation of target biocides obtained from laboratory experiments in order to improve predictions of biocides flows at the city scale from a pre-existing numerical model? 

In order to assess these questions, the PhD student will 

(a) develop in situ studies on the transformation of micropollutants in stormwater retention zones and at the outlets of wastewater treatment plants, based on continuous composite sampling; 

(b) conduct laboratory experiments with selected model compounds for mechanistic insights into their degradation kinetics in specific urban environments; 

(c) plan and conduct field sampling campaigns for target and non-target screening of biocides, taking into account variations in rainfall patterns and biocide usage;

(d) perform hydrochemical analysis, quantitative and qualitative assessment of micropollutants (LC-MS/MS, HR-MS via Orbitrap) and stable isotope analysis on both laboratory and field samples, including use of ME-CSIA for selected representative model micropollutants;

(e) interpret and predict fluxes, transformation, and natural attenuation of urban micropollutants in urban emission sources and receiving key compartments (stormwater retention basins and wastewater treatment plant discharges) quantitatively and qualitatively,  as well as assess the associated ecotoxicological risks;

(f) prepare scientific publications and presentations for scientific conferences.

The succesful candidate has the opportunity to apply high-resolution mass spectrometric analysis techniques as well as stable isotope analysis methods (CSIA via GC-IRMS and other methods) to study and interpret the fate of micropollutants present in urban surface waters and sediments. Besides, he or she will collaborate as part of an interdisciplinary team with external partners (University of Freiburg and Landau, Strasbourg Eurometropolis services) to develop scenarios aimed at reducing urban micropollutant emissions at the source.

The selected candidate will contribute to the development of approaches such as mass balances, conceptual models, and modelling of different scenarios for reducing the use of urban micropollutants at the source. The objective will be to evaluate the emissions and transformation of priority urban micropollutants and their transformation products in key urban aquatic receiving environments, as well as to assess the resulting risks.

We provide comprehensive hands-on training on state-of-the-art analytical devices as well as a flexible working environment, exceptional and continuous mentoring and the opportunity to conduct independent research and to set your own research priorities within the scope of the project.  In cooperation with the CNRS, the ITES also offers various opportunities for personal and professional development.

Work Environment

Research at the University of Strasbourg covers a broad range of scientific fields and actively promotes interdisciplinary and international collaborations. The Institute of Earth & Environment, with approximately 200 collaborators, is structured around four disciplinary pillars to explore earth processes and study the surface environment: hydrology, geochemistry, geology, and geophysics. Within ITES, laboratory and field experiments are conducted to study the transport of water and contaminants.

Our interdisciplinary and international research group focuses specifically on the transformation of pollutants in watersheds, soils, and aquifers and we combine hydrological, microbiological and stable isotope approaches. We offer access to and hands-on experience on a wide range of state-of-the-art analytical devices such as GC-MS, LC-MS/MS and HR-MS (Orbitrap) and we are one of a few research units worldwide which are able to perform CSIA (GC-IRMS, MC-ICP-MS) for a wide range of compounds and isotopes.

Nestled in the heart of Europe, in a socially and economically vibrant trinational region, Strasbourg is not only known for European politics, the high quality of living and a buzzing student life, but also reowned for its commitment to environmental sustainability.

Constraints and Risks

Fieldwork. Laboratory work.

Application Information

Candidates must: 

• Hold a Master's degree or an engineering diploma in environmental sciences, aquatic biogeochemistry, hydrogeology, environmental chemistr or a similar discipline, obtained within the last two years (candidates who obtained their degree after 1st January 2022 will be considered).
• Have experience in fieldwork, hydrochemical analyses, analytical chemistry and/or possibly isotopic analysis.
• Possess good proficiency in English, both written and spoken.
• Demonstrate a proven ability to present scientific results, preferably with at least one article published or in the process of being published in peer-reviewed journals in the field.
• Have strong communication skills and be able to work within an interdisciplinary team composed of scientists, engineers, and technicians. Proven experience in international research is required.
• Preferably have practical knowledge of fieldwork, pollutant transformation, micropollutant chemistry, sampling methods, urban context modelling, and/or high-resolution and stable isotope analysis.

If you wish to apply for the position, please submit as a single PDF file:

• a maximum 2-page cover letter,
• a maximum 3-page thesis plan / research proposal with your scientific interest in and your suitability for this field and project, your proposed methodological approach (excluding figures & tables, references and SI),
• a detailed CV including courses and marks obtained during the master,
• if applicable, a list of publications,
• recommendation letters from two referees, and
•  any other relevant information (e.g. copies of certificates,).

Please note that applications which do not contain all of the elements above will NOT be considered. We are accepting applications as long as this offer is online. The starting date can be handled in a flexible manner. The offered salary and social benefits are according to French public sector regulations (around 2200€ gross per month).

Relevant (co)authored publications 

Höhener, P.; Guers, D.; Malleret, L.; Boukaroum, O.; Martin-Laurent, F.; Masbou, J.; Payraudeau, S.; Imfeld, G. Multi-Elemental Compound-Specific Isotope Analysis of Pesticides for Source Identification and Monitoring of Degradation in Soil: A Review. Environ Chem Lett2022. https://doi.org/10.1007/s10311-022-01489-8.

Hofstetter, T. B.; Bakkour, R.; Buchner, D.; Eisenmann, H.; Fischer, A.; Gehre, M.; Haderlein, S. B.; Höhener, P.; Hunkeler, D.; Imfeld, G.; Jochmann, M. A.; Kümmel, S.; Martin, P. R.; Pati, S. G.; Schmidt, T. C.; Vogt, C.; Elsner, M. Perspectives of Compound-Specific Isotope Analysis of Organic Contaminants for Assessing Environmental Fate and Managing Chemical Pollution. Nat Water2024, 2 (1), 14–30. https://doi.org/10.1038/s44221-023-00176-4.

Liu, X.; Akay, C.; Köpke, J.; Kümmel, S.; Richnow, H. H.; Imfeld, G. Direct Phototransformation of Sulfamethoxazole Characterized by Four-Dimensional Element Compound Specific Isotope Analysis. Environ. Sci. Technol.2024, 58 (23), 10322–10333. https://doi.org/10.1021/acs.est.4c02666.

Borreca, A.; Vuilleumier, S.; Imfeld, G. Combined Effects of Micropollutants and Their Degradation on Prokaryotic Communities at the Sediment–Water Interface. Sci Rep2024, 14 (1), 16840. https://doi.org/10.1038/s41598-024-67308-y.

Sereni, L.; Junginger, T.; J.; Payraudeau, S.; Imfeld, G.. Emissions of the Urban Biocide Terbutryn from Facades to Soil and Stormwater System Estimated over Three Decades. In EGU - Water quality in the soil-groundwater-river continuum: modelling, monitoring and mitigation of micropollutants and pathogens’; Vienne (Austria), Austria, 2023. https://doi.org/10.5194/egusphere-egu23-14583.

Junginger, T.; Payraudeau, S.; Imfeld, G. Transformation and Stable Isotope Fractionation of the Urban Biocide Terbutryn during Biodegradation, Photodegradation and Abiotic Hydrolysis. Chemosphere2022, 305, 135329. https://doi.org/10.1016/j.chemosphere.2022.135329.

Junginger, T.; Payraudeau, S.; Imfeld, G. Emissions of the Urban Biocide Terbutryn from Facades: The Contribution of Transformation Products. Environ. Sci. Technol.2023. https://doi.org/10.1021/acs.est.2c08192.

Cited References

Luthy, R. G.; Sharvelle, S.; Dillon, P. Urban Stormwater to Enhance Water Supply. Environ. Sci. Technol.2019, 53 (10), 5534–5542. https://doi.org/10.1021/acs.est.8b05913.

Zhang, K.; Deletic, A.; Dotto, C. B. S.; Allen, R.; Bach, P. M. Modelling a ‘Business Case’ for Blue-Green Infrastructure: Lessons from the Water Sensitive Cities Toolkit. Blue-Green Systems2020, 2 (1), 383–403. https://doi.org/10.2166/bgs.2020.018.

Wiest, L.; Gosset, A.; Fildier, A.; Libert, C.; Hervé, M.; Sibeud, E.; Giroud, B.; Vulliet, E.; Bastide, T.; Polomé, P.; Perrodin, Y. Occurrence and Removal of Emerging Pollutants in Urban Sewage Treatment Plants Using LC-QToF-MS Suspect Screening and Quantification. Science of The Total Environment2021, 774, 145779. https://doi.org/10.1016/j.scitotenv.2021.145779.

Finckh, S.; Carmona, E.; Borchardt, D.; Büttner, O.; Krauss, M.; Schulze, T.; Yang, S.; Brack, W. Mapping Chemical Footprints of Organic Micropollutants in European Streams. Environment International2024, 183, 108371. https://doi.org/10.1016/j.envint.2023.108371.

Mutzner, L.; Zhang, K.; Luthy, R. G.; Arp, H. P. H.; Spahr, S. Urban Stormwater Capture for Water Supply: Look out for Persistent, Mobile and Toxic Substances. Environ. Sci.: Water Res. Technol.2023, 9 (12), 3094–3102. https://doi.org/10.1039/D3EW00160A.

Bollmann, U. E.; Vollertsen, J.; Carmeliet, J.; Bester, K. Dynamics of Biocide Emissions from Buildings in a Suburban Stormwater Catchment – Concentrations, Mass Loads and Emission Processes. Water Research2014, 56, 66–76. https://doi.org/10.1016/j.watres.2014.02.033.

Challis, J. K.; Popick, H.; Prajapati, S.; Harder, P.; Giesy, J. P.; McPhedran, K.; Brinkmann, M. Occurrences of Tire Rubber-Derived Contaminants in Cold-Climate Urban Runoff. Environ. Sci. Technol. Lett.2021, 8 (11), 961–967. https://doi.org/10.1021/acs.estlett.1c00682.

Zhang, K.; Zheng, Z.; Mutzner, L.; Shi, B.; McCarthy, D.; Le-Clech, P.; Khan, S.; Fletcher, T. D.; Hancock, M.; Deletic, A. Review of Trace Organic Chemicals in Urban Stormwater: Concentrations, Distributions, Risks, and Drivers. Water Research2024, 258, 121782. https://doi.org/10.1016/j.watres.2024.121782.

Gooré Bi, E.; Monette, F.; Gasperi, J. Analysis of the Influence of Rainfall Variables on Urban Effluents Concentrations and Fluxes in Wet Weather. Journal of Hydrology2015, 523, 320–332. https://doi.org/10.1016/j.jhydrol.2015.01.017.

Mutzner, L.; Furrer, V.; Castebrunet, H.; Dittmer, U.; Fuchs, S.; Gernjak, W.; Gromaire, M.-C.; Matzinger, A.; Mikkelsen, P. S.; Selbig, W. R.; Vezzaro, L. A Decade of Monitoring Micropollutants in Urban Wet-Weather Flows: What Did We Learn? Water Research2022, 223, 118968. https://doi.org/10.1016/j.watres.2022.118968.

Yang, Y.; Zhang, X.; Jiang, J.; Han, J.; Li, W.; Li, X.; Yee Leung, K. M.; Snyder, S. A.; Alvarez, P. J. J. Which Micropollutants in Water Environments Deserve More Attention Globally? Environ. Sci. Technol.2022, 56 (1), 13–29. https://doi.org/10.1021/acs.est.1c04250.