Tracing the sources and cycling of phosphorus in river sediments using oxygen isotopes: Methodological adaptations and first results from a case study in France

Autor: Dominique Trevisan, Gérard Gruau, Chiara Pistocchi, Federica Tamburini, Jean-Marcel Dorioz, André Ferhi
Přispěvatelé: Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), 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 Pierre et Marie Curie - Paris 6 (UPMC), Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL), Institut National de la Recherche Agronomique (INRA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), EFPA department of INRA, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Pollution
Geologic Sediments
Environmental Engineering
media_common.quotation_subject
Drainage basin
Soil science
010501 environmental sciences
Oxygen Isotopes
01 natural sciences
Isotopes of oxygen
Soil
Rivers
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry
In-stream processes
Waste Management and Disposal
0105 earth and related environmental sciences
Water Science and Technology
Civil and Structural Engineering
media_common
Hydrology
geography
geography.geographical_feature_category
Ecological Modeling
Sediment
Biota
Phosphorus
Agriculture
04 agricultural and veterinary sciences
Eutrophication
6. Clean water
Phosphorus transfer
13. Climate action
Soil water
Phosphate oxygen isotopes
040103 agronomy & agriculture
0401 agriculture
forestry
and fisheries
Bank
Geology
Environmental Monitoring
Zdroj: Water Research
Water Research, 2017, 111, pp.346-356. ⟨10.1016/j.watres.2016.12.038⟩
Water Research, IWA Publishing, 2017, 111, pp.346-356. ⟨10.1016/j.watres.2016.12.038⟩
ISSN: 0043-1354
Popis: International audience; An essential aspect of eutrophication studies is to trace the ultimate origin of phosphate ions (P-PO4) associated with the solid phase of river sediments, as certain processes can make these ions available for algae. However, this is not a straightforward task because of the diversity of allochthonous and autochthonous sources that can supply P-PO4 to river sediments as well as the existence of in-stream processes that can change the speciation of these inputs and obscure the original sources. Here, we present the results of a study designed to explore the potentials, limitations and conditions for the use of the oxygen isotope composition of phosphate (δ18Op) extracted from river sediments for this type of tracing. We first tested if the method commonly applied to soils to purify P-PO4 and to measure their δ18Op concentrations could be adapted to sediments. We then applied this method to a set of sediments collected in a river along a gradient of anthropogenic pressure and compared their isotopic signatures with those from samples that are representative of the potential P-PO4 inputs to the river system (soils and riverbank material).The results showed that following some adaptations, the purification method could be successfully transposed to river sediments with a high level of P-PO4 purification (>97%) and high δ18Op measurement repeatability and accuracy (3‰) in the sediment δ18Op value immediately downstream from the discharge point revealed the strong impact of municipal wastewater. The calculation of the theoretical equilibrium δ18Op values using the river water temperature and δ18Ow showed that the downstream sediments were in equilibrium, which was not the case for the upstream sediments. This difference could be related to the contrast between the short residence time of the transfer system in the catchment head, which can preserve the isotopic variability of the source materials, and the longer residence times and higher P bioavailability in the lower catchment, possibly fostering the recycling of P-PO4 by the biota and the equilibration of the oxygen isotope signature in P-PO4. These results demonstrate the potential of the isotopic approach to assess the sources and in-stream turnover of sedimentary P in river systems.
Databáze: OpenAIRE
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