Thallium Long-Term Fate from Rock-Deposit to Soil: The Jas Roux Sulfosalt Natural Analogue
2023
Rose, Jérôme | Chaurand, Perrine | Dentant, Cédric | Angeletti, Bernard | Borschneck, Daniel | Kieffer, Isabelle | Proux, Olivier | Bonet, Richard | Auffan, Mélanie | Levard, Clément | Fehlauer, Till | Collin, Blanche | Doelsch, Emmanuel | Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE) ; Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) | Pacte, Laboratoire de sciences sociales (PACTE) ; Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Sciences Po Grenoble - Institut d'études politiques de Grenoble (IEPG) ; Université Grenoble Alpes (UGA) | Parc national des Ecrins | Observatoire des Sciences de l'Univers de Grenoble (OSUG ) ; Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]) | Recyclage et risque (UPR Recyclage et risque) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)
Inorganic contaminant release resulting frommining activities can impact surrounding ecosystems. Ores formedby primary sulfide minerals produce sulfuric acid after mineraloxidation, which is the driving force of metal release. Yet secondarymetal sulfates may form and play a crucial role in controlling themetal fate. In the case of thallium (Tl), it has been shown that innatural Tl-rich sulfide deposits and those found in mining areas, Tlcan be trapped by Tl-jarosite (Tl-rich iron sulfate) anddorallcharite (TlFe3(SO4)2(OH)6). Our Tl speciation characterizationresults have generated novel insight into the long-termbehavior of this metal derived from a unique natural hotspot: theJas Roux site (France). The biogeochemical cycle of the soilecosystems of Jas Roux dates back almost 15000 years ago and has now reached a steady state. A chemical gradient was found insoils across the toposequence underlying the Jas Roux outcrop. X-ray absorption spectroscopy revealed that Tl was mainly present insecondary minerals at the top of the studied zone. Oxidative dissolution of Tl-rich sulfide minerals and pyrite accounts for thepresence of Tl-jarosite in soils, either by direct formation in soils or by gravity erosion from the outcrop. The Tl-jarosite quantity wasfound to decrease from the top to the bottom of the toposequence, probably due to sulfate leaching. Released Tl likely adsorbed onphyllosilicates such as Illite or muscovite, and a fraction of Tl was found to have oxidized into Tl(III) along the toposequence.
显示更多 [+] 显示较少 [-]