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Cadmium distribution in mature durum wheat grains using dissection, laser ablation-ICP-MS and synchrotron techniques *
2020
Yan, Bofang | Isaure, Marie-Pierre | Mounicou, Sandra | Castillo-Michel, Hiram | De Nolf, Wout | Nguyen, Christophe | Cornu, Jean-Yves
Understanding how essential and toxic elements are distributed in cereal grains is a key to improving the nutritional quality of cereal-based products. The main objective of this work was to characterize the distribution of Cd and of nutrients (notably Cu, Fe, Mn, P, S and Zn) in the durum wheat grain. Laser ablation inductively coupled mass spectrometry and synchrotron micro X-ray fluorescence were used for micro-scale mapping of Cd and nutrients. A dissection approach was used to quantitatively assess the distribution of Cd and nutrients among grain tissues. Micro X-ray absorption near-edge spectroscopy was used to identify the Cd chemical environment in the crease. Cadmium distribution was characterized by strong accumulation in the crease and by non-negligible dissemination in the endosperm. Inside the crease, Cd accumulated most in the pigment strand where it was mainly associated with sulfur ligands. High-resolution maps highlighted very specific accumulation areas of some nutrients in the germ, for instance Mo in the root cortex primordia and Cu in the scutellum. Cadmium loading into the grain appears to be highly restricted. In the grain, Cd co-localized with several nutrients, notably Mn and Zn, which challenges the idea of selectively removing Cd-enriched fractions by dedicated milling process.
显示更多 [+] 显示较少 [-]Modelling bioaccumulation of heavy metals in soil-crop ecosystems and identifying its controlling factors using machine learning
2020
Hu, Bifeng | Xue, Jie | Zhou, Yin | Shao, Shuai | Fu, Zhiyi | Li, Yan | Chen, Songchao | Qi, Lin | Shi, Zhou | Unité de Science du Sol (Orléans) (URSols) ; Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resource Sciences ; Zhejiang University [Hangzhou, China] | Institute of Land Science and Property, School of Public Affairs ; Zhejiang University [Hangzhou, China] | School of Earth Sciences [Hangzhou] ; Zhejiang University [Hangzhou, China] | InfoSol (InfoSol) ; Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Ningbo Planting Management Station ; Ningbo University (NBU)
The prediction and identification of the factors controlling heavy metal transfer in soil-crop ecosystems are of critical importance. In this study, random forest (RF), gradient boosted machine (GBM), and generalised linear (GLM) models were compared after being used to model and identify prior factors that affect the transfer of heavy metals (HMs) in soil-crop systems in the Yangtze River Delta, China, based on 13 covariates with 1822 pairs of soil-crop samples. The mean bioaccumulation factors (BAFs) for all crops followed the order Cd > Zn > As > Cu > Ni > Hg > Cr > Pb. The RF model showed the best prediction ability for the BAFs of HMs in soil-crop ecosystems, followed by GBM and GLM. The R2 values of the RF models for the BAFs of Zn, Cu, Cr, Ni, Hg, Cd, As, and Pb were 0.84, 0.66, 0.59, 0.58, 0.58, 0.51, 0.30, and 0.17, respectively. The primary controlling factor in soil-to-crop transfer of all HMs under study was plant type, followed by soil heavy metal content and soil organic materials. The model used herein could be used to assist the prediction of heavy metal contents in crops based on heavy metal contents in soil and other covariates, and can significantly reduce the cost, labour, and time requirements involved with laboratory analysis. It can also be used to quantify the importance of variables and identify potential control factors in heavy metal bioaccumulation in soil-crop ecosystems.
显示更多 [+] 显示较少 [-]Current status, spatial features, health risks, and potential driving factors of soil heavy metal pollution in China at province level
2020
Hu, Bifeng | Shao, Shuai | Ni, Hao | Fu, Zhiyi | Hu, Linshu | Zhou, Yin | Min, Xiaoxiao | She, Shufeng | Chen, Songchao | Huang, Mingxiang | Zhou, Lianqing | Li, Yan | Shi, Zhou | Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resource Sciences ; Zhejiang University [Hangzhou, China] | Unité de Science du Sol (Orléans) (URSols) ; Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Université d'Orléans (UO) | Department of Earth System Science [Tsinghua] ; Tsinghua University [Beijing] (THU) | School of Earth Sciences, Zhejiang University (ZJU) | College of Environmental and Resource Sciences, Zhejiang University | Institute of Land Science and Property, School of Public Affairs ; Zhejiang University [Hangzhou, China] | InfoSol (InfoSol) ; Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Information Center of Ministry of Ecology and Environment | Institute of Agricultural Remote Sensing and Information Technology Application ; Zhejiang University [Hangzhou, China]
International audience | In this study we systematically reviewed 1203 research papers published between 2008 and 2018 in China and recorded related data on eight kinds of soil heavy metals (Cr, Pb, Cd, Hg, As, Cu, Zn, and Ni). Based on that, the pollution levels, ecological risk and health risk caused by soil heavy metals were evaluated and the pollution hot spots and potential driving factors of different heavy metals in different provinces were also identified. Results indicated accumulation of heavy metals in soils of most provinces in China compared with background values. Consistent with previous findings, the most prevalent polluted heavy metals were Cd and Hg. Polluted regions are mainly located in central, southern and southwestern China. Hunan, Guangxi, Yunnan, and Guangdong provinces were the most polluted provinces. For the potential health risk caused by heavy metals pollution, children are more likely confront with non-carcinogenic risk than adults and seniors. And children in Hunan and Guangxi province were experiencing relatively larger non-carcinogenic risk. In addition, children in part of provinces were undergoing potentially carcinogenic risks due to soil heavy metals exposure. Furthermore, in our study the 31 provinces in mainland China were divided into six subsets according to corresponding potential driving factors for heavy metal accumulation. Our study provide more comprehensive and updated information for contributing to better soil management, soil remediation, and soil contamination control in China.
显示更多 [+] 显示较少 [-]Surface modifications at the oxide/water interface: implications for Cu binding, solution chemistry and chemical stability of iron oxide nanoparticles
2020
Demangeat, Edwige | Pédrot, Mathieu | Dia, Aline | Bouhnik-Le Coz, Martine | Davranche, Mélanie | Cabello-Hurtado, Francisco | Géosciences Rennes (GR) ; Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR) ; Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS) | Université de Rennes (UR) | Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO) ; Université de Rennes (UR)-Institut Ecologie et Environnement (INEE) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR) ; Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS) | Centre National de la Recherche Scientifique INSU/INEE EC2CO | Inter-disciplinary Mission programs through the NanoOrgaTraces’ and ‘ALIEN’project | the University of Rennes “Défis Scientifiques Emergents”
International audience | The oxidation of magnetite into maghemite and its coating by natural organic constituents are common changes that affect the reactivity of iron oxide nanoparticles (IONP) in aqueous environments. Certain ubiquitous compounds such as humic acids (HA) and phosphatidylcholine (PC), displaying a high affinity for both copper (Cu) and IONP, could play a critical role in the interactions involved between both compounds. The adsorption of Cu onto four different IONP was studied: magnetite nanoparticles (magnNP), maghemite NP (maghNP), HA- and PC-coated magnetite NP (HA-magnNP and PC-magnNP, respectively). According to the results, the percentage of adsorbed Cu increases with increasing pH, irrespective of the IONP. Thus, protonation/deprotonation reactions are likely involved within Cu adsorption mechanism. Contrary to the other studied IONP, HA-magnNP favor Cu adsorption at most of the pH tested including acidic pH (pH = 3), suggesting that part of the active surface sites for Cu2+ were not grabbed by protons. The Freundlich adsorption isotherm of HA-magnNP provides the highest sorption constant KF (bonding energy) and n value which supports a heterogeneous sorption process. The heterogeneous adsorption between HA-magnNP and Cu2+ can be explained by both the diversity of the binding sites HA procured and the formation of multidendate complexes between Cu2+ and some of the HA functional groups. Such favorable adsorption process was neither observed on PC-coated-magnNP nor on maghNP, whose behaviors were comparable to that of magnNP. On another hand, HA and PC coatings considerably reduced iron (Fe) dissolution from magnNP as compared with magnNP. It was suggested that HA and PC coatings either provided efficient shield against Fe leaching or fostered dissolved Fe re-adsorption onto the functional groups at the coated magnNP surfaces. Thus, this study can help to better understand the complex interfacial reactions between cations-organic matter-colloidal surfaces which are relevant in environmental and agricultural contexts.This work showed that magnetite NP properties can be affected by surface modifications, which drive NP chemical stability and Cu adsorption, thereby affecting the global water chemistry.
显示更多 [+] 显示较少 [-]Associations between persistent organic pollutants and endometriosis: A multipollutant assessment using machine learning algorithms
2020
Matta, Komodo | Vigneau, Evelyne | Cariou, Véronique | Mouret, Delphine | Ploteau, Stéphane | Le Bizec, Bruno | Antignac, Jean-Philippe | Cano-Sancho, Germán | Laboratoire d'étude des Résidus et Contaminants dans les Aliments (LABERCA) ; École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Statistique, Sensométrie et Chimiométrie (StatSC) ; École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Centre hospitalier universitaire de Nantes (CHU Nantes)
International audience
显示更多 [+] 显示较少 [-]Early-life exposure to artificial light at night elevates physiological stress in free-living songbirds
2020
Grunst, Melissa | Raap, Thomas | Grunst, Andrea | Pinxten, Rianne | Parenteau, Charline | Angelier, Frédéric | Eens, Marcel | Department of Biology, Behavioural Ecology and Ecophysiology Group ; University of Antwerp (UA) | Department of Biology (Ethology) ; University of Antwerp (UA) | Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC) ; La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Department of Biology (Ethology) ; University of Antwerp (UA) | ANR-16-CE02-0004,URBASTRESS,Influence de l'urbanisation sur les populations de vertébrés: une approche éco-physiologique(2016)
International audience | Artificial light at night (ALAN) can disrupt adaptive patterns of physiology and behavior that promote high fitness, resulting in physiological stress and elevation of steroid glucocorticoids (corticosterone, CORT in birds). Elevated CORT may have particularly profound effects early in life, with the potential for enduring effects that persist into adulthood. Research on the consequences of early-life exposure to ALAN remains limited, especially outside of the laboratory, and the effects of early-life light exposure on CORT concentrations in wild nestling birds remain to be elucidated. We used an experimental setup to test the hypothesis that ALAN elevates CORT concentrations in developing free-living birds, by exposing nestling great tits (Parus major) to ALAN inside nest boxes. We measured CORT in feathers grown over the timeframe of the experiment (7 nights), such that CORT concentrations represent an integrative metric of hormone release over the period of nocturnal light exposure, and of development. We also assessed the relationships between feather CORT concentrations, body condition, nestling size rank and fledging success. In addition, we evaluated the relationship between feather CORT concentrations and telomere length. Nestlings exposed to ALAN had higher feather CORT concentrations than control nestlings, and nestlings in poorer body condition and smaller brood members also had higher CORT. On the other hand, telomere length, fledging success, and recruitment rate were not significantly associated with light exposure or feather CORT concentrations. Results indicate that exposure to ALAN elevates CORT concentrations in nestlings, which may reflect physiological stress. In addition, the organizational effects of CORT are known to be substantial. Thus, despite the lack of effect on telomere length and survivorship, elevated CORT concentrations in nestlings exposed to ALAN may have subsequent impacts on later-life fitness and stress sensitivity.
显示更多 [+] 显示较少 [-]Data fusion for the measurement of potentially toxic elements in soil using portable spectrometers
2020
Xu, Dongyun | Chen, Songchao | Xu, Hanyi | Wang, Nan | Zhou, Yin | Shi, Zhou | Zhejiang University [Hangzhou, China] | InfoSol (InfoSol) ; Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Ministry of Agriculture
International audience | Soil contamination posed by potentially toxic elements is becoming more serious under continuously development of industrialization and the abuse of fertilizers and pesticides. The investigation of soil potentially toxic elements is therefore urgently needed to ensure human and other organisms’ health. In this study, we investigated the feasibility of the separate and combined use of portable X-ray fluorescence (pXRF) and visible near-infrared reflectance (vis-NIR) sensors for measuring eight potentially toxic elements in soil. Low-level fusion was achieved by the direct combination of the pXRF and vis-NIR spectra; middle-level fusion was achieved by the combination of selected bands of the pXRF and vis-NIR spectra using the Boruta feature selection algorithm; and high-level fusion was conducted by outer-product analysis (OPA) and Granger–Ramanathan averaging (GRA). The estimation accuracy for the eight considered elements were in the following order: Zn > Cu > Ni > Cr > As > Cd > Pb > Hg. The measurement for Cu and Zn could be achieved by pXRF spectra alone with Lin’s concordance correlation coefficient (LCCC) values of 0.96 and 0.98, and ratio of performance to interquartile distance (RPIQ) values of 2.36 and 2.69, respectively. The measurement of Ni had the highest model performance for high-level fusion GRA with LCCC of 0.89 and RPIQ of 3.42. The measurements of Cr using middle- and high-level fusion were similar, with LCCC of 0.86 and RPIQ of 2.97. The best estimation accuracy for As, Cd, and Pb were obtained by high-level fusion using OPA, with LCCC >0.72 and RPIQ >1.2. However, Hg measurement by these techniques failed, having an unacceptable performance of LCCC <0.20 and RPIQ <0.75. These results confirm the effectiveness of using portable spectrometers to determine the contents of several potentially toxic elements in soils.
显示更多 [+] 显示较少 [-]Early-life exposure to artificial light at night elevates physiological stress in free-living songbirds
2020
Grunst, Melissa | Raap, Thomas | Grunst, Andrea | Pinxten, Rianne | Parenteau, Charline | Angelier, Frédéric | Eens, Marcel | Department of Biology, Behavioural Ecology and Ecophysiology Group ; University of Antwerp (UA) | Department of Biology (Ethology) ; University of Antwerp (UA) | Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC) ; La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Department of Biology (Ethology) ; University of Antwerp (UA) | ANR-16-CE02-0004,URBASTRESS,Influence de l'urbanisation sur les populations de vertébrés: une approche éco-physiologique(2016)
International audience | Artificial light at night (ALAN) can disrupt adaptive patterns of physiology and behavior that promote high fitness, resulting in physiological stress and elevation of steroid glucocorticoids (corticosterone, CORT in birds). Elevated CORT may have particularly profound effects early in life, with the potential for enduring effects that persist into adulthood. Research on the consequences of early-life exposure to ALAN remains limited, especially outside of the laboratory, and the effects of early-life light exposure on CORT concentrations in wild nestling birds remain to be elucidated. We used an experimental setup to test the hypothesis that ALAN elevates CORT concentrations in developing free-living birds, by exposing nestling great tits (Parus major) to ALAN inside nest boxes. We measured CORT in feathers grown over the timeframe of the experiment (7 nights), such that CORT concentrations represent an integrative metric of hormone release over the period of nocturnal light exposure, and of development. We also assessed the relationships between feather CORT concentrations, body condition, nestling size rank and fledging success. In addition, we evaluated the relationship between feather CORT concentrations and telomere length. Nestlings exposed to ALAN had higher feather CORT concentrations than control nestlings, and nestlings in poorer body condition and smaller brood members also had higher CORT. On the other hand, telomere length, fledging success, and recruitment rate were not significantly associated with light exposure or feather CORT concentrations. Results indicate that exposure to ALAN elevates CORT concentrations in nestlings, which may reflect physiological stress. In addition, the organizational effects of CORT are known to be substantial. Thus, despite the lack of effect on telomere length and survivorship, elevated CORT concentrations in nestlings exposed to ALAN may have subsequent impacts on later-life fitness and stress sensitivity.
显示更多 [+] 显示较少 [-]Surface modifications at the oxide/water interface: implications for Cu binding, solution chemistry and chemical stability of iron oxide nanoparticles
2020
Demangeat, Edwige | Pédrot, Mathieu | Dia, Aline | Bouhnik-Le Coz, Martine | Davranche, Mélanie | Cabello-Hurtado, Francisco | Géosciences Rennes (GR) ; Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR) ; Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS) | Université de Rennes (UR) | Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO) ; Université de Rennes (UR)-Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR) ; Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS) | Centre National de la Recherche Scientifique INSU/INEE EC2CO | Inter-disciplinary Mission programs through the NanoOrgaTraces’ and ‘ALIEN’project | the University of Rennes “Défis Scientifiques Emergents”
International audience | The oxidation of magnetite into maghemite and its coating by natural organic constituents are common changes that affect the reactivity of iron oxide nanoparticles (IONP) in aqueous environments. Certain ubiquitous compounds such as humic acids (HA) and phosphatidylcholine (PC), displaying a high affinity for both copper (Cu) and IONP, could play a critical role in the interactions involved between both compounds. The adsorption of Cu onto four different IONP was studied: magnetite nanoparticles (magnNP), maghemite NP (maghNP), HA- and PC-coated magnetite NP (HA-magnNP and PC-magnNP, respectively). According to the results, the percentage of adsorbed Cu increases with increasing pH, irrespective of the IONP. Thus, protonation/deprotonation reactions are likely involved within Cu adsorption mechanism. Contrary to the other studied IONP, HA-magnNP favor Cu adsorption at most of the pH tested including acidic pH (pH = 3), suggesting that part of the active surface sites for Cu2+ were not grabbed by protons. The Freundlich adsorption isotherm of HA-magnNP provides the highest sorption constant KF (bonding energy) and n value which supports a heterogeneous sorption process. The heterogeneous adsorption between HA-magnNP and Cu2+ can be explained by both the diversity of the binding sites HA procured and the formation of multidendate complexes between Cu2+ and some of the HA functional groups. Such favorable adsorption process was neither observed on PC-coated-magnNP nor on maghNP, whose behaviors were comparable to that of magnNP. On another hand, HA and PC coatings considerably reduced iron (Fe) dissolution from magnNP as compared with magnNP. It was suggested that HA and PC coatings either provided efficient shield against Fe leaching or fostered dissolved Fe re-adsorption onto the functional groups at the coated magnNP surfaces. Thus, this study can help to better understand the complex interfacial reactions between cations-organic matter-colloidal surfaces which are relevant in environmental and agricultural contexts.This work showed that magnetite NP properties can be affected by surface modifications, which drive NP chemical stability and Cu adsorption, thereby affecting the global water chemistry.
显示更多 [+] 显示较少 [-]Strong temporal and spatial variation of dissolved Cu isotope composition in acid mine drainage under contrasted hydrological conditions
2020
Masbou, J. | Viers, Jérôme | Grande, Jose Antonio | Freydier, R. | Zouiten, Cyril | Seyler, Patrick | Pokrovsky, O.S., S | Behra, Philippe | Dubreuil, Brigitte | de La Torre, M.L. | Laboratoire d'Hydrologie et de Géochimie de Strasbourg (LHyGeS) ; Ecole et Observatoire des Sciences de la Terre (EOST) ; Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) | Géosciences Environnement Toulouse (GET) ; Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) ; Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) | Universidad de Huelva | Hydrosciences Montpellier (HSM) ; Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) | Tomsk State University [Tomsk] | Chimie Agro-Industrielle (CAI) ; Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques (ENSIACET) ; Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Ecole d'Ingénieurs de Purpan (INP - PURPAN) ; Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | his work was supported by the EC2CO program of the INSU/CNRS institution and by the European Union for co-funding SOIL TAKE CARE SOE1/P4/F0023 through the European Regional Development Fund (ERDF), under the Interreg SUDOE Program. This work was also partly supported by the EQUIPEX CRITEX programme (grant no. ANR-11-EQPX-0011, Pls. J. Gaillardet and L. Longuevergne) | ANR-11-EQPX-0011,CRITEX,Parc national d'équipements innovants pour l'étude spatiale et temporelle de la Zone Critique des Bassins Versants(2011)
International audience | Copper export and mobility in acid mine drainage are difficult to understand with conventional approaches. Within this context, Cu isotopes could be a powerful tool and here we have examined the relative abundance of dissolved (<0.22 μm) Cu isotopes (δ65Cu) in the Meca River which is an outlet of the Tharsis mine, one of the largest abandoned mines of the Iberian Pyrite Belt, Spain. We followed the chemical and isotopic composition of the upstream and downstream points of the catchment during a 24-h diel cycle. Additional δ65Cu values were obtained from the tributary stream, suspended matter (>0.22 μm) and bed sediments samples. Our goals were to 1) assess Cu sources variability at the upstream point under contrasted hydrological conditions and 2) investigate the conservative vs. non conservative Cu behavior along a stream. Average δ65Cu values varied from -0.47 to -0.08‰ (n = 9) upstream and from -0.63 to -0.31‰ downstream (n = 7) demonstrating that Cu isotopes are heterogeneous over the diel cycle and along the Meca River. During dry conditions, at the upstream point of the Meca River the Cu isotopic composition was heavier which is in agreement with the preferential release of heavy isotopes during the oxidative dissolution of primary sulfides. The more negative values obtained during high water flow are explained by the contribution of soil and waste deposit weathering. Finally, a comparison of upstream vs. downstream Cu isotope composition is consistent with a conservative behavior of Cu, and isotope mass balance calculations estimate that 87% of dissolved Cu detected downstream originate from the Tharsis mine outlet. These interpretations were supported by thermodynamic modelling and sediment characterization data (X-ray diffraction, Raman Spectroscopy). Overall, based on contrasted hydrological conditions (dry vs flooded), and taking the advantage of isotope insensitivity to dilution, the present work demonstrates the efficiency of using the Cu isotopes approach for tracing sources and processes in the AMD regions.
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