The origin of Uranium in groundwater of the eastern Halkidiki region, northern Greece.

Autor: Kazakis N; Aristotle University of Thessaloniki, School of Geology, Laboratory of Engineering Geology and Hydrogeology, 54124 Thessaloniki, Greece. Electronic address: kazakis@geo.auth.gr., Busico G; Aristotle University of Thessaloniki, School of Geology, Laboratory of Engineering Geology and Hydrogeology, 54124 Thessaloniki, Greece; University of Campania 'Luigi Vanvitelli', Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Via Vivaldi 43, 81100 Caserta, Italy., Ntona MM; Aristotle University of Thessaloniki, School of Geology, Laboratory of Engineering Geology and Hydrogeology, 54124 Thessaloniki, Greece; University of Campania 'Luigi Vanvitelli', Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Via Vivaldi 43, 81100 Caserta, Italy., Philippou K; Department of Chemistry, University of Cyprus, 75, Kallipoleos Avenue, P.O. Box 20537, 1678 Nicosia, Cyprus., Kaprara E; Aristotle University of Thessaloniki, Department of Chemical Engineering, 54124 Thessaloniki, Greece., Mitrakas M; Aristotle University of Thessaloniki, Department of Chemical Engineering, 54124 Thessaloniki, Greece., Bannenberg M; Department of Chemistry, University of Cyprus, 75, Kallipoleos Avenue, P.O. Box 20537, 1678 Nicosia, Cyprus., Ioannidou A; Physics Department, Nuclear Physics Laboratory, Aristotle University of Thessaloniki, Thessaloniki, Greece., Pashalidis I; Department of Chemistry, University of Cyprus, 75, Kallipoleos Avenue, P.O. Box 20537, 1678 Nicosia, Cyprus., Colombani N; Polytechnic University of Marche, Department of Materials, Environmental Sciences and Urban Planning, Via Brecce Bianche 12, 60131 Ancona, Italy., Mastrocicco M; University of Campania 'Luigi Vanvitelli', Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Via Vivaldi 43, 81100 Caserta, Italy., Voudouris K; Aristotle University of Thessaloniki, School of Geology, Laboratory of Engineering Geology and Hydrogeology, 54124 Thessaloniki, Greece.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2022 Mar 15; Vol. 812, pp. 152445. Date of Electronic Publication: 2021 Dec 21.
DOI: 10.1016/j.scitotenv.2021.152445
Abstrakt: Uranium (U) pollution in groundwater has become a serious problem worldwide. Even in low concentrations, U has both radiological and toxicological impacts on human health. In this study an integrated hydrogeological approach was applied to conceptualize an aquifer system, and determine the origin of U detected in the aquifer of the eastern Halkidiki region in northern Greece. Data from measurements of groundwater level and hydrochemical and stable isotope analyses of groundwater samples were applied to perform geochemical modeling and multivariate statistical analysis. The modeling and statistical analysis identified three hydrogeochemical groups within the studied hydro-system, and U(VI) as the dominant U species. The first group is linked to the deeper aquifer which is characterized by water-rock interactions with weathering products of granodiorite. In this group the dominant U species is uranyl phosphate and U concentration is 3.7 μg/L. The upper aquifer corresponds to the second hydrogeochemical group where U concentrations are mainly influenced by high concentrations of nitrogen species (NO 3 - and NO 2 - ). Factor analysis further discriminated the upper aquifer into a saline coastal zone and an inland zone impacted by agricultural activities. The third hydrogeochemical group presents the highest concentration of U (up to 15 μg/L) in groundwater and corresponds to the internal aquifer system. The U within this system is triggered by the presence of Mn 2+ , while the long residence time of the groundwater contributes synergistically to the hydrogeochemical process. Manganese triggers U oxidation in parallel with Fe 2+ precipitation that acts as a regulator of U concentration. Groundwater depletion of the upper aquifers promotes the up-coning of geothermal fluids from fault zones leading to increased concentrations of U in the mid-depth aquifers.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2021 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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