PhD projects

The RESCUE doctoral candidates (DCs) will work on collaborative PhD projects spanning topics from fundamental understanding of contaminant behaviour and geophysical signatures, through high-resolution site characterisation (HRSC) and conceptual site model (CSM) development, to monitoring contamination and remediation processes, and socio-economic, legal and sustainability assessment across different contaminant types, geophysical methods, and spatial scales. The projects are embedded within different RESCUE work packages (WPs) and involve close collaboration through joint research activities, secondments, and network-wide training and exchange.

The PhD project descriptions below provide information on the research objectives, expected results, contaminant types and geophysical methods addressed, and planned secondments.

Contaminant abbreviations: PFAS = per- and polyfluoroalkyl substances; HM = heavy metals; PHC = petroleum hydrocarbons; CHC = chlorinated hydrocarbons.

Geophysical method abbreviations: ERT = electrical resistivity tomography; (S)IP = (spectral) induced polarization; FDEM/TEM = frequency-/time-domain electromagnetics; GPR = ground penetrating radar; NMR = nuclear magnetic resonance; SEIS = seismics; µCT = X-ray micro-computed tomography.

Objectives:

• To quantify the relationship between selected contaminants and geophysical signatures (SIP and NMR) under controlled laboratory conditions.
• To develop a coupled digital rock-physics (DRP) and multiphysics simulation framework that mechanistically links pore-scale flow, reactive transport, and geophysical response.
• To validate laboratory data against pilot- and field-scale data to improve the interpretation of geophysical monitoring.

Expected Results:

• Mechanistic understanding of how contaminant type, concentration, phase saturation, and associated geochemical conditions (pH and ionic strength) control SIP and NMR responses.
• Validated DRP-based petrophysical models predicting SIP and NMR signals under multiphase conditions.
• A new multiphysics framework dynamically integrating pore-scale fluid dynamics, geochemical reactions, and electrodynamics.

Contaminants: HM, PFAS

Geophysical methods: SIP, NMR

Planned Secondments:

• S1.1. UGent (3 months): Training in µCT imaging and DRP to derive pore-scale models predicting SIP and NMR responses under multiphase conditions, with T. Bultreys.
• S1.2. FZJ (2 months): Participation in field campaigns at the Krauthausen site, acquiring and integrating SIP with borehole NMR and GPR data, with A. Klotzsche.
• S1.3. Geolinks (2 months): Petrophysical interpretation of passive seismic data, with T. Kremer.
• S1.4. GeoSphere Austria (2 months): Field training in planning, acquisition, and interpretation of geophysical surveys to complement SIP/NMR analyses, with I. Schlögel.

Objectives:

• To evaluate PFAS transport behaviour under varying geochemical conditions.
• To investigate interaction mechanisms with HM, including competitive sorption, complexation, and redox effects.
• To integrate geophysical methods (SIP) to monitor contaminant migration at lab scale.
• To numerically simulate PFAS-HM co-migration, with AI-driven approaches, and study geophysical detectability.

Expected Results:

• Dataset capturing PFAS transport behaviour under varying geochemical conditions, including co-occurring HM.
• Understanding of PFAS mobility, revealing how co-contaminants influence environmental persistence and exposure pathways.
• Modelling framework supporting risk assessments and remediation technologies design.
• Geophysical-geochemical-AI framework as a basis for translation to field-scale applications.

Contaminants: HM, PFAS

Geophysical methods: ERT/IP, SIP

Planned Secondments:

• S2.1. UStutt (3 months): Training in advanced unsaturated-zone experiments and subsurface modelling to support PFAS-metal transport model calibration.
• S2.2. SU (4 months): Development and testing of AI-physics integration approaches for contaminant transport modelling.
• S2.3. Geosyntec (1 month): Exposure to PFAS prediction tools and risk-assessment workflows to link model outputs to applied site remediation.

Objectives:

• To develop a petrophysical model of complex electrical conductivity using SIP and µCT in variably saturated soil, including uncertainty.
• To characterise the SIP response of hydrocarbon contamination, and to investigate this response under natural attenuation and enhanced (bio)remediation using dynamic experiments.

Expected Results:

• Validated probabilistic petrophysical model for variably-saturated soil linking SIP signals with pore size distribution (obtained with µCT) and cation exchange capacity.
• Mechanistic understanding of how contaminant type, concentration, phase saturation, (bio)degradation control the SIP response.

Contaminants: CHC, PHC

Geophysical methods: SIP

Planned Secondments:

• S3.1. SU (3 months): Petrophysical modelling under uncontaminated conditions to compare probabilistic and mechanistic petrophysical approaches, with D. Jougnot.
• S3.2. EUT (2 months): Laboratory training for dynamic experiments with CHC and PHC, integration of SIP into existing laboratory setups, with L. del Val Alonso and C. Bosch.
• S3.3. ERM (1 month): Exposure to practical and regulatory aspects of site remediation, analysing how geophysics can support legal evidence of contamination, with L. Thomas.

Objectives:

• To develop geophysical soil characterisation workflows to delineate management zones and support phytomanagement decisions at multi-contaminated pilot sites using ground-based and drone-based geophysics.
• To integrate geophysics with conventional soil analyses to monitor changes in soil properties and conditions (soil health), and vegetation development.
• To assess the fate and mobility of contaminants (e.g., HM, PHC) within the soil–water–plant system and relate geophysical variations to biological, chemical, physical soil health indicators.
• To provide guidelines and decision-support tools for adaptive management and stakeholder engagement.

Expected Results:

• Improved understanding of how subsurface heterogeneity affects soil health and vegetation performance under phytomanagement, supporting more targeted interventions.
• Quantitative links between geophysical signals and biological/chemical indicators in the shallow root zone.
• Insights into (co-)contaminant behaviour within the soil–water–plant system under different phytomanagement configurations.
• Adaptive monitoring and management frameworks, enabling scalable and replicable brownfield rehabilitation.

Contaminants: HM, PHC, PFAS

Geophysical methods: GPR, FDEM, ERT

Planned Secondments:

• S4.1. UGent (8 months): Training in GPR/FDEM/ERT workflows for soil characterisation; acquisition and interpretation of (time-lapse, TL) datasets, with P. De Smedt.
• S4.2. Siterem (2 months): Exposure to consultancy practice to validate geophysical workflows and integrate results into phytomanagement planning, with V. Vanderheyden.
• S4.3. LIST (2 months): Development of soil health indicators aligned with the Soil Monitoring Law; guidelines and best practices for GISR for phytomanagement (M30), with A. Espinoza.

Objectives:

• To develop and test new probabilistic inversion methodology enabling uncertainty quantification (UQ) and direct estimation of hydrological parameters from TEM data.
• To integrate geophysical and hydrological modelling to enhance prediction of flow and transport processes at contaminated sites.
• To evaluate the methodology on synthetic (digital twins) and real datasets and benchmark it against existing approaches for hydrological parameter estimation.

Expected Results:

• Validated probabilistic inversion methodology providing spatially distributed hydrological parameters with quantified uncertainty.
• Improved reliability of hydrological parameter estimation for modelling groundwater flow and contaminant transport.
• Framework for integrated geophysical–hydrological inversion contributing to improved CSM development and supporting risk assessment, remedial design, and monitoring.

Contaminants: PHC, PFAS

Geophysical methods: TEM

Planned Secondments:

• S5.1. SU (3 months): Co-development of AI-based approaches to enhance computational efficiency of probabilistic inversion, with L. Bodet.
• S5.2. UGent (2 months): Comparison with numerical simulation-based prediction approaches (Bayesian Evidential Learning, BEL), with T. Hermans and E. Van De Vijver.
• S5.3. Central Denmark Region (1 month): Exposure to practical and regulatory aspects of site remediation, analysing how geophysics can support legal evidence of contamination, with F. Jørgensen.

Objectives:

• To develop and test a new (joint) probabilistic hierarchical inversion methodology for FDEM and ERT, enabling multi-level UQ.
• To integrate geophysical inverse modelling with petrophysical modelling for direct estimation of petrophysical properties, including contamination.
• To evaluate the methodology on synthetic (digital twins) and real contaminated site datasets, assessing its applicability for HRSC and CSM development.

Expected Results:

• Validated probabilistic hierarchical (joint) inversion methodology, providing quantified multi-level uncertainties across data and model components, including petrophysics.
• Improved reliability and consistency of contamination detection and delineation through consistent multi-source geophysical and conventional data integration, supporting CSM development, risk assessment, and remedial design.

Contaminants: PHC, CHC

Geophysical methods: FDEM, ERT

Planned Secondments:

• S6.1. TAUW (1 month): Exposure to consultancy practice in site remediation, focusing on practical workflows, regulatory frameworks, and decision-making processes, with H. De Wilde.
• S6.2. AU (3 months): Comparison of probabilistic inversion strategies for FDEM and TEM data, with T. Mejer Hansen and L. Meldgaard Madsen.
• S6.3. ULiège (3 months): Comparison of probabilistic inversion with BEL to characterize heterogeneity, with F. Nguyen and D. Caterina.

Objectives:

• To develop new physics-aware AI-based inversion for hybrid (active–passive) seismic data, enabling efficient and uncertainty-aware subsurface modelling
• To optimize data-acquisition and processing strategies minimising field and computational demands while preserving physical realism.
• To develop seismic-petrophysical models adapted to conditions encountered at contaminated sites.

Expected Results:

• Validated and benchmarked open-source physics-aware AI-based inversion methodology for hybrid seismic data, enabling reliable and uncertainty-aware estimation of subsurface properties and conditions at contaminated sites.
• Optimised data-acquisition and processing strategies that minimise field and computational effort without compromising model fidelity.
• Demonstrated applicability of the developed workflows for both site characterisation and time-lapse (TL) monitoring of contaminant and remediation processes.

Contaminants: PHC, PFAS

Geophysical methods: SEIS

Planned Secondments:

• S7.1. FZJ (3 months): Joint seismic-GPR field campaign at the Krauthausen site, integrated workflows for characterisation and monitoring, with A. Klotzsche and J. Vanderborght.
• S7.2. ULiège (2 months): Alternative inversion strategies and adaptation of AI-based tools for seismic applications, with F. Nguyen and D. Caterina.
• S7.3. Geolinks (2 months): Experimentation, proof-of-concept and validation of hybrid seismic workflows at a contaminated site, with T. Kremer.

Objectives:

• To improve the mechanistic understanding of PFAS retention and transport processes in the unsaturated zone, and to identify the spatial and temporal resolutions required for effective monitoring.
• To establish geophysical–hydrological relationships enabling the estimation of soil moisture dynamics and associated PFAS mass fluxes.
• To integrate SIP and NMR data for high-resolution monitoring of hydrodynamic parameters.
• To develop and validate a multi-method monitoring workflow to quantify in-situ PFAS mass fluxes.

Expected Results:

• Fundamental understanding of the dynamic geophysical response to unsaturated flow and associated PFAS retention and transport.
• New experimental benchmark datasets, digital twins, and calibrated and validated relationships linking SIP and NMR responses to hydrodynamic processes and PFAS retention and transport.
• Validated multi-method monitoring workflow for the quantitative estimation of PFAS fluxes in the unsaturated zone, across laboratory, pilot, and field scales and forming the basis for practitioner guidelines.

Contaminants: PFAS

Geophysical methods: NMR, SIP

Planned Secondments:

• S8.1. UniVie (3 months): Experience with NMR and SIP laboratory setups for quantifying water saturation and PFAS-related processes under controlled conditions, with C. Zhang.
• S8.2. Arcadis (3 months): Pilot-scale application of geophysical monitoring of soil moisture and PFAS at test sites in Reilingen (aqueous film forming foam, AFFF) and in Hügelsheim (biosolid-contaminated agricultural field), with M. Reinhard, T. Heitmann, and M. Bester (output: real field datasets and draft workflow protocol).
• S8.3. PFAS-Geschäftsstelle, Landratsamt Rastatt (1 month): Exposure to regulatory and administrative procedures for PFAS-contaminated site management and integration of innovative monitoring approaches, with R. Söhlmann.

Objectives:

• To develop new TL ERT inversion methodologies based on: (1) “standard” Tikhonov regularisation, for simply yet robust prior knowledge incorporation, and (2) deep generative model training, for realistic reconstruction of spatiotemporal subsurface variations.
• To evaluate inversion performance using coupled reactive flow-and-transport simulations and realistic noise characterisation.
• To assess the robustness, sensitivity, and interpretation uncertainty on synthetic and real cases, representing variable contamination and remediation scenarios.

Expected Results:

• Validated TL ERT inversion methodologies targeting improved recovery of spatiotemporal subsurface variations under realistic contamination and remediation conditions.
• Corresponding open-source inversion code and openly accessible benchmark datasets (synthetic and field).
• Evaluated method performance across varying subsurface conditions and monitoring targets, and datasets of different sources and quality.

Contaminants: PHC, CHC

Geophysical methods: ERT

Planned Secondments:

• S9.1. SU (3 months): Development of synthetic benchmark datasets, including petrophysics, and integration of seismic data in the TL ERT inversion, with L. Bodet and D. Jougnot.
• S9.2. EUT (3 months): Acquisition of real ERT field datasets at EUT’s full-scale bioremediation pilots (LIFE InBioSoil project); testing of the TL ERT workflow under real site conditions, with L. del Val Alonso, C. Bosch, and S. Jou (output: field datasets and joint paper).
• S9.3. Canopea (1 month): Exposure to environmental policy frameworks and stakeholder decision-making relevant to contaminated-site management, with A. Defourny.

Objectives:

• To develop and test a 4-D GPR full-waveform inversion (FWI) workflow for monitoring flow and transport of contaminants and (injected) (bio)remediation agents.
• To optimise data acquisition via digital-twin technologies.
• To establish quantitative petrophysical relationships between GPR-derived parameters (permittivity, electrical conductivity) and subsurface properties and conditions relevant to contamination and remediation.
• To extend the workflow from cross-borehole to borehole-to-surface and surface GPR.

Expected Results:

• Operational 4-D GPR FWI workflow for high-resolution TL imaging of subsurface changes, including responses to flow and transport of contamination and the distribution of injected remediation agents – validated at the Krauthausen site and demonstrated on at least one real remediation case.
• A digital twin of the Krauthausen site, benchmark datasets for inversion and petrophysical model evaluation, quantitative relationships linking GPR-derived parameters to subsurface changes related to contamination and remediation processes.

Contaminants: PHC, CHC

Geophysical methods: GPR

Planned Secondments:

• S10.1. AU (3 months): Training and field practice in NMR and towed TEM, and assessment of the potential to extend from deterministic to probabilistic GPR FWI, with T. Mejer Hansen, L. Meldgaard Madsen, and A. V. Andersen.
• S10.2. EUT (2 months): Training in in-situ bioremediation (biostimulation and bioaugmentation), including current monitoring and performance-evaluation practices. Joint field campaign at EUT’s full-scale bioremediation pilots (LIFE InBioSoil project) to collect TL GPR datasets and assess the workflow under real field conditions, with L. del Val Alonso, C. Bosch, S. Jou (output: real field datasets and joint paper).
• S10.3. Injectis (2 months): Training in injection-based (bio)remediation and application of GPR FWI to injected-based remediation case, with J. Vandenbruwane and L. Counet.

Objectives:

• To develop and evaluate the use of ERT/IP to optimise the design, implementation, and monitoring of electrochemical nanoremediation (ENR) using nanoscale zero-valent iron (nZVI).
• To advance understanding of the (geophysical responses to) nZVI distribution, transport and reactivity, and induced remediation processes.
• To explore and assess the feasibility of dual-use electrode systems enabling both direct current (DC) application and geoelectrical measuring for enhanced ENR monitoring and process control.
• To upscale from laboratory experiments to pilot-scale tests under operational field conditions as part of a real remediation project.

Expected Results:

• Operational ERT-based workflow for improved design, implementation, and performance assessment of ENR using nZVI, validated from laboratory experiments through pilot-scale testing and evaluated under operational field conditions.
• Prototype dual-use electrode configuration, including proof-of-feasibility tests.
• Benchmark datasets, processing protocols and interpretation guidelines supporting geophysics-informed/integrated optimisation of ENR for future research and practical exploitation.

Contaminants: PFAS, CHC, HM

Geophysical methods: ERT/IP

Planned Secondments:

• S11.1. UGent (4 months): Training in ERT/IP data acquisition, processing and interpretation; test of ERT monitoring of ENR in sandbox-OhmPi setup, with E. Van De Vijver and T. Hermans.
• S11.2. Technical University of Liberec (4 months): Further development and testing of ERT-informed ERN. Development and preliminary testing of prototype OhmPi system with dual-use electrodes in lab experiments, with J. Nosek and A. Pavelková.
• S11.3. UStutt (4 months): Upscaling, refinement and validation of ERT-informed ERN and prototype dual-use electrode system to pilot-scale tests, with S. Kleinknecht and C. Haslauer.

Objectives:

• To develop an advanced ERT/IP monitoring workflow to support the design, implementation and evaluation of bioremediation via injection-based bioaugmentation, and mycoremediation in particular.
• To understand the geophysical responses to contaminant and amendment distribution, fate and transport, associated processes (microbial and fungal biomass dynamics, biofilm formation).
• To apply the workflow at operational remediation site.

Expected Results:

• Validated ERT monitoring workflow for tracking amendment distribution and bioremediation progress under operational field conditions.
• Understanding of ERT responses to bioaugmentation (mycoremediation) processes.
• Full-scale benchmark datasets, processing protocols, and practitioner-oriented guidelines for geophysics-informed design, implementation, and evaluation of injection-based bioremediation campaigns.

Contaminants: PHC, CHC

Geophysical methods: ERT

Planned Secondments:

• S12.1. ULiège (4 months): Hands-on training in ERT and (S)IP data acquisition, processing, and interpretation at laboratory and field scale, with F. Nguyen and D. Caterina.
• S12.2. University of Barcelona (1 month): Field-scale application of ERT monitoring to full-scale bioremediation pilots (LIFE InBioSoil project), with A. Marcuello and P. Queralt (output: real field datasets and joint paper).
• S12.3. Brussels Airport Company (1 month): Exposure to site-owner decision-making, regulatory constraints, and practical considerations for contaminated site investigation and remediation, with N. Soenens.

Objectives:

• To develop a context-sensitive methodology for assessing and monitoring soil health using geophysics to characterize and manage contaminated soils, integrating soil health descriptors, ecosystem services, and EU regulatory frameworks.
• To simulate site-specific phytomanagement, combining system dynamic modelling of the ecological processes, economic analysis, and life cycle assessment (LCA) into a unified, evidence-based approach.

Expected Results:

• A comprehensive, context-sensitive framework integrating geophysical methods with soil health assessment and regulatory requirements defined by EU policies (incl. “Soil Monitoring Law”), connecting biophysical and economic descriptors across urban and peri-urban settings.
• Site-specific evaluation of phytomanagement strategies through implementation within the enhanced NBenefit$ tool.

Contaminants: Cross-cutting

Geophysical methods: Cross-cutting

Planned Secondments:

• S13.1. UGent (3 months): Training on relevant geophysical methods for the characterisation and monitoring of contaminated sites, with E. Van De Vijver, P. De Smedt, and T. Hermans.
• S13.2. LiU (4 months): Collection of economic (Life Cycle Costing) and environmental (LCA) data to develop the NBenefit$ tool, with J. Johansson, N. Svensson, and J. L. Esguerra.
• S13.3. Università degli Studi di Milano-Bicocca (4 months): Study of plant-microorganisms interaction for air-pollutant removal to design and calibrate the system dynamic model in NBenefit$, with A. Franzetti.
• S13.4. Siterem (1 month): Application of NBenefit$ tool to a real case study in Wallonia, with V. Vanderheyden, S. Schadeck, and L. Niemirowski.

Objectives:

• To develop and apply a generic methodology for assessing environmental impacts and ecosystem services of both conventional and geophysics-informed remediation strategies in different project settings and institutional contexts.

Expected Results:

• A generic methodology capable of benchmarking the environmental impacts and ecosystem services of different conventional and geophysics-informed remediation strategies, facilitating project planning and implementation.
• Key knowledge on generically critical factors in terms of different project settings and institutional contexts influencing the selection of environmentally preferable remediation strategies with high ecosystem services.

Contaminants: Cross-cutting

Geophysical methods: Cross-cutting

Planned Secondments:

• S14.1. UGent (3 months) Learning about geophysical methods in remediation applications and different methodologies for ecosystem services assessment (ESA), with E. Van De Vijver.
• S14.2. Ossiado (2 months): Training on regenerative soil restoration in urban (re)development, with E. Vermeulen (Ossiado).
• S14.3. LIST (2 months) Joint synthesizing work with DC 13 & 14 related to the overall WP4 objectives.

Objectives:

• To develop a methodology for assessing techno- and socio-economic performance of conventional and geophysics-informed remediation strategies and perform a trade-off analysis against other sustainability criteria.
• To contrast the results to key remediation stakeholders’ preferences, perspectives and interests.

Expected Results:

• Comparison of the techno- and socio-economic impacts of different conventional and geophysics-informed remediation strategies in different project settings.
• An improved understanding of the trade-offs between economic and environmental performance related to geophysics-informed remediation strategies.

Contaminants: Cross-cutting

Geophysical methods: Cross-cutting

Planned Secondments:

• S15.1. ULiège (2 months): Specialised training in nature-based solutions and phytomanagement, with C. Nouet and M. Hanikenne (ULiège).
• S15.2. OVAM (2 months): Hands-on experience on remediation planning and implementation with special emphasis on key stakeholders, existing sustainability frameworks, and institutional conditions influencing decision-making.
• S15.3. LIST (3 months): Joint synthesizing work with DCs 13 and 14 related to the overall objectives of WP4.