title: Evaluation of the origin of sulphate at the groundwater source Ključ, Serbia.
abstract: The dual-isotope method of measuring both the δ(34)S and δ(18)O values of dissolved sulphate to assess the origin and fate of groundwater sulphate at the Ključ groundwater source, Serbia is applied. A sampling campaign was conducted in September 2007 during low-flow conditions, obtaining river water and groundwater from observation wells completed in a shallow aquifer formed in alluvial sandy-gravelly sediments. In the shallow groundwater, sulphate concentrations ranged from 56.2 to 165.0 mg l(-1). The δ(34)S values of sulphate varied from-5.5 to+3.0 ‰ and [Formula: see text] values from+1.4 to+4.2 ‰. Oxidation of pedospheric (organic soil S) and lithogenic sulphur sources (e.g. pyrite) were identified as the main causes for the increasing sulphate concentrations in the analysed groundwater. This study shows that combining hydrological, chemical, and isotopic techniques is a powerful approach to identifying sources and processes that control sulphate in water resources.
authors.affiliation: Jaroslav Černi Institute for Development of Water Resources, Belgrade, Serbia. emiljevi@vinca.rs
authors.forename: Nada
authors.initials: N
authors.lastname: Miljević
authors.forename: Djulija
authors.initials: D
authors.lastname: Boreli-Zdravković
authors.forename: Jovana
authors.initials: J
authors.lastname: Veličković
authors.forename: Dušan
authors.initials: D
authors.lastname: Golobočanin
authors.forename: Bernhard
authors.initials: B
authors.lastname: Mayer
mesh_terms: D004784:Environmental Monitoring; D060587:Groundwater / Q000737:chemistry*; D010103:Oxygen Isotopes / Q000032:analysis; D055771:Serbia; D013431:Sulfates / Q000032:analysis*; D013460:Sulfur Isotopes / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply / Q000032:analysis
chemical_list: D010103:Oxygen Isotopes; D013431:Sulfates; D013460:Sulfur Isotopes; D014874:Water Pollutants, Chemical