Liège University - Hydrogeology & Environmental Geology

The GEO³ (Geotechnologies, Hydrogeology, Geophysical Prospecting) research team at the University of Liège (Belgium) is made up of 5 internationally recognised permanent members and around ten non-permanent members (PhD students, postdocs, research engineers). The postdoctoral researcher will be supervised by Serge Brouyère, a professor at the University of Liège specialising in groundwater quality and pollution. The postdoctoral researcher will have the opportunity to attend international conferences, workshops and summer schools.

Homepage: https://www.uee.uliege.be/cms/c_3680052/en/ueenew-hydrogeologie-et-geologie-de-l-environnement

Postdoc description:

For several years, the Hydrogeology and Environmental Geology team at the University of Liège has been developing innovative approaches aimed at mapping the vulnerability of groundwater (Apsû method, Popescu et al. 2019, Brouyère et al. 2021) and to assess the risk of groundwater pollution at different scales, from the polluted industrial site to the scale of aquifers via the catchment areas (PolluESO approach, Jamin et al. 2012, Brouyère et al. 2022). The common specificity developed with these various projects is that the risk assessment is systematically based on the pollutants fluxes and mass discharge rates into and through groundwater. The REPAIRS project, funded as part of the Feder SWaM@Sc project portfolio, aims to further develop such flux-based risk assessment approaches.

The two existing core tools (Apsû and PolluESO) are based on the same module for calculating the leaching of pollutants from the soil surface to the groundwater saturated zone, through a series of soil and geological horizons (“cascading” model). This module considers advection, hydrodynamic dispersion, retardation (linear sorption) and linear degradation processes. In PolluESO, the leaching module calculates a mass flow that feeds a Modflow-MT3D numerical model to calculate the dispersion of the pollutant in the groundwater saturated zone.
However, such approaches have several limitations. Degradation of some pollutants can generate products which themselves present a certain risk (e.g. relevant metabolites of pesticides, chlorinated solvents, etc.). In addition, according to the basic principle of the mass flux approach, if the groundwater is located in a less permeable medium, the spreading of the pollutant will be limited, and the volume of contaminated groundwater will be small. It is therefore possible to envisage situations where the pollution remains very local and the groundwater as a whole is only marginally affected.

In this context, the aim of the postdoctoral research is twofold. Firstly, the leaching module will be improved to include more complex degradation reactions, such as degradation (of parent molecules) and production (of daughter molecules). Secondly, the leaching module will be supplemented by a simplified dispersion module based on an approach similar to that developed in the BRGM’s MISP tool (Guyonnet 2001). In a second step, the newly developed modules will be incorporated into the Apsû and PolluESO tools for carrying pollutants leaching and dispersion risk assessment studies through groundwater. A webGIS application could also be envisaged.

A 18-month work contract is offered as part of the REPAIRS project. The person recruited will have a post-doctoral employment contract at the University of Liège. The position must be filled as soon as possible, as the project ends in December 2025.

Requirements:

Holder of a PhD in geosciences and/or environmental sciences with good references in scientific programming (development of calculation codes and interfacing).
Experience in groundwater flow and reactive transport modelling.
Good knowledge of English (spoken and written). Knowledge of French is an advantage but not a requirement.

References:

Popescu, I.-C., Brouyère, S., & Dassargues, A. (2019). The APSÛ method for process-based groundwater vulnerability assessment. Hydrogeology Journal. doi:10.1007/s10040-019-02013-z, https://hdl.handle.net/2268/238771
Brouyère, S., Balzani, L., & Orban, P. (2022). The CASPER project: an integrated approach for pollution risk assessment in peri-urban groundwater catchment areas. Advances in Geosciences, 59, 45-51. doi:10.5194/adgeo-59-45-2022, https://hdl.handle.net/2268/297326
Jamin, P., Dollé, F., Chisala, B., Orban, P., Popescu, I. C., Hériveaux, C., Dassargues, A., & Brouyère, S. (2012). A regional flux-based risk assessment approach for multiple contaminated sites on groundwater bodies. Journal of Contaminant Hydrology, 127 (1-4), 65-75. doi:10.1016/j.jconhyd.2011.07.001, https://hdl.handle.net/2268/101984
Brouyère, S., Micella, I., Thomas, C., Orban, P., Popescu, I.-C., & Dassargues, A. (09 September 2021). Recent advances in the use of process-based groundwater vulnerability for risk mapping [Paper presentation]. 48ème Congrès Annuel de l’Association Internationale des Hydrogéologues (AIH – IAH), Bruxelles, Belgium. https://hdl.handle.net/2268/263438
Guyonnet, D. (2001) – MISP_v1. An analytical model for estimating impact of pollutant sources on groundwater. User’s guide. BRGM Report RP-51040-FR

The candidate must provide:
- A motivation letter describing his/her research interests, aptitudes and motivations for the position.
- A detailed CV including a list of previous research work and publications, if any.
- The names and contacts of two referees (one of whom must be the principal supervisor of the candidate’s PhD thesis or equivalent).
- Diplomas (or translations) attesting to the successful completion of a PhD thesis.
- Any relevant document likely to support the application.

Applications must be submitted by email (pdf format) in French or English (all supporting documents must be translated into one of these languages).

Interested candidates are invited to contact Serge Brouyère (serge.brouyere@uliege.be) to discuss the post-doctorate offer.