La polarisation provoquée des particules métalliques: Retour d'expériences de terrain et en laboratoire

International audienceInduced polarization (IP) has been used to characterize past metallurgical sites and deposits as part of the NWE-REGENERATIS project. This presentation is based on the results obtained for the Pompey site (FR) to develop the adopted methodology: Classic approach to which is added (3) Targeted sampling; (4) Laboratory geochemical analyzes (XRF); (5) Geostatistical analysis of correlations between IP and geochemical datasets; (6) Quantitative interpretation using a geostatistical approach that makes it possible to distinguish between different volumes and to associate a joint probability of occurrence.La polarisation provoquée (PP) a été utilisée pour caractériser d'anciens sites et gisements métallurgiques dans le cadre du projet NWE-REGENERATIS. Cette présentation s'appuie sur les résultats obtenus pour le site de Pompey (FR) pour développer la méthodologie retenue : Approche classique à laquelle s'ajoute (3) Echantillonnage ciblé ; (4) Analyses géochimiques en laboratoire (XRF) ; (5) Analyse géostatistique des corrélations entre données PP et géochimiques ; (6) Interprétation quantitative à l'aide d'une approche géostatistique qui permet de distinguer différents volumes de composition chimique différente et d'y associer une probabilité jointe d'occurrence

La polarisation provoquée des particules métalliques: Retour d'expériences de terrain et en laboratoire

International audienceInduced polarization (IP) has been used to characterize past metallurgical sites and deposits as part of the NWE-REGENERATIS project. This presentation is based on the results obtained for the Pompey site (FR) to develop the adopted methodology: Classic approach to which is added (3) Targeted sampling; (4) Laboratory geochemical analyzes (XRF); (5) Geostatistical analysis of correlations between IP and geochemical datasets; (6) Quantitative interpretation using a geostatistical approach that makes it possible to distinguish between different volumes and to associate a joint probability of occurrence.La polarisation provoquée (PP) a été utilisée pour caractériser d'anciens sites et gisements métallurgiques dans le cadre du projet NWE-REGENERATIS. Cette présentation s'appuie sur les résultats obtenus pour le site de Pompey (FR) pour développer la méthodologie retenue : Approche classique à laquelle s'ajoute (3) Echantillonnage ciblé ; (4) Analyses géochimiques en laboratoire (XRF) ; (5) Analyse géostatistique des corrélations entre données PP et géochimiques ; (6) Interprétation quantitative à l'aide d'une approche géostatistique qui permet de distinguer différents volumes de composition chimique différente et d'y associer une probabilité jointe d'occurrence

IP signature of metallic particles: lessons learnt from field and laboratory experiments

International audiencePast metallurgical sites and deposits account for a significant proportion of potentially contaminated sites in the European Union (EU): about 100,000 have been identified only in the North West regions of the EU. While recent wastes from sites still in operation are commonly recovered, this is not the case for old aggregated materials with a high content of ferrous (and other) metals, white and black slag, etc., which are considered to be sources of pollution and are costly to manage or dispose of. These sites could be considered as opportunities to recover large volumes of resources (metals, materials and land) using urban mining techniques if they were better characterized

IP signature of metallic particles: lessons learnt from field and laboratory experiments

International audiencePast metallurgical sites and deposits account for a significant proportion of potentially contaminated sites in the European Union (EU): about 100,000 have been identified only in the North West regions of the EU. While recent wastes from sites still in operation are commonly recovered, this is not the case for old aggregated materials with a high content of ferrous (and other) metals, white and black slag, etc., which are considered to be sources of pollution and are costly to manage or dispose of. These sites could be considered as opportunities to recover large volumes of resources (metals, materials and land) using urban mining techniques if they were better characterized

Vadose zone water content characterization of a heterogeneous limestone by 3D-SNMR

International audienceIn the current climate change context, the quality and availability of water resource are important society issues. Indeed, the consumption of water and fertilizers by farms and their discharge into the soil and aquifers leads to a critical environmental situation. To manage the effect and fate of these contaminations, it is necessary to have a relevant knowledge of the vadose zone dynamics and exchanges especially flow paths from the soil to the deep aquifers. Parts of the vadose zone are well studied such as the first meters with an adapted instrumentation, and the water table properties with piezometric measurements and pumping tests. The geophysics methods allow studying the deep vadose zone properties. The surface nuclear magnetic resonance (SNMR) is a direct geophysical method based on the protons magnetic resonance to measure water content in the subsurface. This method can be used to detect the water table level coupled with hydrogeological measurements (piezometric measurements and pumping tests) or to characterize aquifers properties and boundaries coupled with other geophysical methods (electrical, EM or gravimetric methods). The current study is carried out in Villamblain (France) at the heart of the Beauce region; one of the most cultivated and highly nitrate-contaminated area in France. The vadose zone is a highly heterogeneous limestone with geochemical alteration, complex network of fractures and karstification. This field site was chosen to develop an observatory of transfers in the Vadose Zone named O-ZNS (https://plateformes-pivots.eu/o-zns/). This observatory consists of an exceptional well (20 m-deep and 4 m-diameter) equipped with multiple sensors and accessible for direct characterization of the heterogeneous vadose zone, surrounded by 8 boreholes used for water sampling, geophysical well-logging, piezometric level monitoring and vadose zone geochemical properties monitoring. In this study, the SNMR method is used (1) to characterize the spatial heterogeneities of the 3D aquifer and of the vadose zone limestone, in a 3D-model jointly interpreted with other geophysical measurements (3D-ERT, 3D-IP, gravimetric, GPR profiles) and soundings; (2) to characterize the vadose zone water content, in combination with GPR and NMR logging water content profiles. Both these works are ongoing. This research aims to know more accurately the vadose zone water content measured by SNMR in the context of a heterogeneous limestone with the goal to monitor the vadose zone flow dynamics with time-lapse measurements coupled with hydrogeological measurements

Vadose zone water content characterization of a heterogeneous limestone by 3D-SNMR

International audienceIn the current climate change context, the quality and availability of water resource are important society issues. Indeed, the consumption of water and fertilizers by farms and their discharge into the soil and aquifers leads to a critical environmental situation. To manage the effect and fate of these contaminations, it is necessary to have a relevant knowledge of the vadose zone dynamics and exchanges especially flow paths from the soil to the deep aquifers. Parts of the vadose zone are well studied such as the first meters with an adapted instrumentation, and the water table properties with piezometric measurements and pumping tests. The geophysics methods allow studying the deep vadose zone properties. The surface nuclear magnetic resonance (SNMR) is a direct geophysical method based on the protons magnetic resonance to measure water content in the subsurface. This method can be used to detect the water table level coupled with hydrogeological measurements (piezometric measurements and pumping tests) or to characterize aquifers properties and boundaries coupled with other geophysical methods (electrical, EM or gravimetric methods). The current study is carried out in Villamblain (France) at the heart of the Beauce region; one of the most cultivated and highly nitrate-contaminated area in France. The vadose zone is a highly heterogeneous limestone with geochemical alteration, complex network of fractures and karstification. This field site was chosen to develop an observatory of transfers in the Vadose Zone named O-ZNS (https://plateformes-pivots.eu/o-zns/). This observatory consists of an exceptional well (20 m-deep and 4 m-diameter) equipped with multiple sensors and accessible for direct characterization of the heterogeneous vadose zone, surrounded by 8 boreholes used for water sampling, geophysical well-logging, piezometric level monitoring and vadose zone geochemical properties monitoring. In this study, the SNMR method is used (1) to characterize the spatial heterogeneities of the 3D aquifer and of the vadose zone limestone, in a 3D-model jointly interpreted with other geophysical measurements (3D-ERT, 3D-IP, gravimetric, GPR profiles) and soundings; (2) to characterize the vadose zone water content, in combination with GPR and NMR logging water content profiles. Both these works are ongoing. This research aims to know more accurately the vadose zone water content measured by SNMR in the context of a heterogeneous limestone with the goal to monitor the vadose zone flow dynamics with time-lapse measurements coupled with hydrogeological measurements

Vadose zone water content characterization of a heterogeneous limestone by 3D-SNMR

International audienceIn the current climate change context, the quality and availability of water resource are important society issues. Indeed, the consumption of water and fertilizers by farms and their discharge into the soil and aquifers leads to a critical environmental situation. To manage the effect and fate of these contaminations, it is necessary to have a relevant knowledge of the vadose zone dynamics and exchanges especially flow paths from the soil to the deep aquifers. Parts of the vadose zone are well studied such as the first meters with an adapted instrumentation, and the water table properties with piezometric measurements and pumping tests. The geophysics methods allow studying the deep vadose zone properties. The surface nuclear magnetic resonance (SNMR) is a direct geophysical method based on the protons magnetic resonance to measure water content in the subsurface. This method can be used to detect the water table level coupled with hydrogeological measurements (piezometric measurements and pumping tests) or to characterize aquifers properties and boundaries coupled with other geophysical methods (electrical, EM or gravimetric methods). The current study is carried out in Villamblain (France) at the heart of the Beauce region; one of the most cultivated and highly nitrate-contaminated area in France. The vadose zone is a highly heterogeneous limestone with geochemical alteration, complex network of fractures and karstification. This field site was chosen to develop an observatory of transfers in the Vadose Zone named O-ZNS (https://plateformes-pivots.eu/o-zns/). This observatory consists of an exceptional well (20 m-deep and 4 m-diameter) equipped with multiple sensors and accessible for direct characterization of the heterogeneous vadose zone, surrounded by 8 boreholes used for water sampling, geophysical well-logging, piezometric level monitoring and vadose zone geochemical properties monitoring. In this study, the SNMR method is used (1) to characterize the spatial heterogeneities of the 3D aquifer and of the vadose zone limestone, in a 3D-model jointly interpreted with other geophysical measurements (3D-ERT, 3D-IP, gravimetric, GPR profiles) and soundings; (2) to characterize the vadose zone water content, in combination with GPR and NMR logging water content profiles. Both these works are ongoing. This research aims to know more accurately the vadose zone water content measured by SNMR in the context of a heterogeneous limestone with the goal to monitor the vadose zone flow dynamics with time-lapse measurements coupled with hydrogeological measurements

Vadose zone water content characterization of a heterogeneous limestone by 3D-SNMR

International audienceIn the current climate change context, the quality and availability of water resource are important society issues. Indeed, the consumption of water and fertilizers by farms and their discharge into the soil and aquifers leads to a critical environmental situation. To manage the effect and fate of these contaminations, it is necessary to have a relevant knowledge of the vadose zone dynamics and exchanges especially flow paths from the soil to the deep aquifers. Parts of the vadose zone are well studied such as the first meters with an adapted instrumentation, and the water table properties with piezometric measurements and pumping tests. The geophysics methods allow studying the deep vadose zone properties. The surface nuclear magnetic resonance (SNMR) is a direct geophysical method based on the protons magnetic resonance to measure water content in the subsurface. This method can be used to detect the water table level coupled with hydrogeological measurements (piezometric measurements and pumping tests) or to characterize aquifers properties and boundaries coupled with other geophysical methods (electrical, EM or gravimetric methods). The current study is carried out in Villamblain (France) at the heart of the Beauce region; one of the most cultivated and highly nitrate-contaminated area in France. The vadose zone is a highly heterogeneous limestone with geochemical alteration, complex network of fractures and karstification. This field site was chosen to develop an observatory of transfers in the Vadose Zone named O-ZNS (https://plateformes-pivots.eu/o-zns/). This observatory consists of an exceptional well (20 m-deep and 4 m-diameter) equipped with multiple sensors and accessible for direct characterization of the heterogeneous vadose zone, surrounded by 8 boreholes used for water sampling, geophysical well-logging, piezometric level monitoring and vadose zone geochemical properties monitoring. In this study, the SNMR method is used (1) to characterize the spatial heterogeneities of the 3D aquifer and of the vadose zone limestone, in a 3D-model jointly interpreted with other geophysical measurements (3D-ERT, 3D-IP, gravimetric, GPR profiles) and soundings; (2) to characterize the vadose zone water content, in combination with GPR and NMR logging water content profiles. Both these works are ongoing. This research aims to know more accurately the vadose zone water content measured by SNMR in the context of a heterogeneous limestone with the goal to monitor the vadose zone flow dynamics with time-lapse measurements coupled with hydrogeological measurements

Caractérisation géophysique multi-méthodes et multi-échelles de la ZNS des calcaires hétérogènes de Beauce

International audienceThe water cycle issue needs a relevant knowledge of the vadose zone dynamics and particularly of the deep vadose zone. The joint interpretation of SNMR and electrical results with log data in the Beauce heterogeneous weathered limestone allows distinguishing a spatial variability at decametric scale with two areas with variable lithological and hydrogeological properties: a karstified fractured limestone, which assumes fast flows and a highly clayey weathered fractured limestone, which assumes a barrier without flows.L’enjeu sur la compréhension du cycle d’eau nécessite une connaissance fine de la dynamique dans la zone non saturée (ZNS) et particulièrement la ZNS profonde. L’interprétation jointe des résultats électriques et RMP et des données de forage dans les calcaires hétérogènes altérés de Beauce permet de distinguer une variabilité spatiale à l’échelle décamétrique avec deux zones du milieu aux propriétés lithologiques et hydrogéologiques différentes : un calcaire fracturé karstifié supposant des écoulements rapides et un calcaire fracturé très altéré argileux supposant une barrière sans écoulements