title: Determination of the sources of nitrate and the microbiological sources of pollution in the Sava River Basin.
abstract: Coupled measurements of nitrate (NO3-), nitrogen (N), and oxygen (O) isotopic composition (δ15NNO3and δ18ONO3) were used to investigate the sources and processes of N cycling, while the microbial source tracking (MST) method was used to identify microbiological pollution in the surface water of the Sava River Basin (SRB) in autumn in 2014 and 2015 during high and low water discharge. Atmospheric nitrate deposition or nitrate-containing fertilizers were found not to be significant sources of riverine nitrate in the SRB. The ranges of isotope values suggest that NO3-in the SRB derives from soil nitrification, sewage, and/or manure, which were further supported by MST analysis. Microbiological indicators show the existence of hotspots of fecal pollution in the SRB, which are human associated. Long-term observations indicate persistent fecal contamination at selected locations caused by continuous discharge of untreated wastewaters into the SRB.
authors: Department of Geography, University of Munich, Luisenstraße 37, 80333 Munich, Germany; Jožef Stefan International Postgraduate School, Jamova ulica 39, 1000 Ljubljana, Slovenia. Electronic address: j.vrzel@iggf.geo.uni-muenchen.de.
authors: Janja
authors: J
authors: Vrzel
authors: University of Belgrade, Faculty of Biology, Chair of Microbiology, Center for Genotoxicology and Ecogenotoxicology, Studentski trg 16, 11000 Belgrade, Serbia. Electronic address: brankavg@bio.bg.ac.rs.
authors: Branka
authors: B
authors: Vuković-Gačić
authors: University of Belgrade, Faculty of Biology, Chair of Microbiology, Center for Genotoxicology and Ecogenotoxicology, Studentski trg 16, 11000 Belgrade, Serbia. Electronic address: stoimirk@bio.bg.ac.rs.
authors: Stoimir
authors: S
authors: Kolarević
authors: University of Belgrade, Institute for Multidisciplinary Research, Kneza Višeslava 1, 11030 Belgrade, Serbia. Electronic address: zorga@imsi.rs.
authors: Zoran
authors: Z
authors: Gačić
authors: University of Belgrade, Institute for Biological Research ¨Siniša Stanković¨, Bulevar despota Stefana 142, 11060 Belgrade, Serbia. Electronic address: margareta.kracun@ibiss.bg.ac.rs.
authors: Margareta
authors: M
authors: Kračun-Kolarević
authors: University of Belgrade, Institute for Multidisciplinary Research, Kneza Višeslava 1, 11030 Belgrade, Serbia. Electronic address: kosticjovana@hotmail.com.
authors: Jovana
authors: J
authors: Kostić
authors: University of Belgrade, Faculty of Biology, Chair of Microbiology, Center for Genotoxicology and Ecogenotoxicology, Studentski trg 16, 11000 Belgrade, Serbia. Electronic address: mustafab@bio.bg.ac.rs.
authors: Mustafa
authors: M
authors: Aborgiba
authors: Vienna University of Technology, Institute for Chemical Engineering, Research Group Environmental Microbiology and Molecular Ecology, The Interuniversity Cooperation Centre Water & Health, Gumpendorfer Straße 1a, 1060 Vienna, Austria. Electronic address: andreas.farnleitner@wavenet.at.
authors: Andreas
authors: A
authors: Farnleitner
authors: Vienna University of Technology, Institute for Chemical Engineering, Research Group Environmental Microbiology and Molecular Ecology, The Interuniversity Cooperation Centre Water & Health, Gumpendorfer Straße 1a, 1060 Vienna, Austria. Electronic address: georg.reischer@tuwien.ac.at.
authors: Georg
authors: G
authors: Reischer
authors: Vienna University of Technology, Institute for Chemical Engineering, Research Group Environmental Microbiology and Molecular Ecology, The Interuniversity Cooperation Centre Water & Health, Gumpendorfer Straße 1a, 1060 Vienna, Austria. Electronic address: rita.linke@tuwien.ac.at.
authors: Rita
authors: R
authors: Linke
authors: University of Belgrade, Institute for Biological Research ¨Siniša Stanković¨, Bulevar despota Stefana 142, 11060 Belgrade, Serbia. Electronic address: mpaunovi@ibiss.bg.ac.rs.
authors: Momir
authors: M
authors: Paunović
authors: Jožef Stefan International Postgraduate School, Jamova ulica 39, 1000 Ljubljana, Slovenia; Department of Environmental Sciences, Jožef Stefan Institute, Jamova ulica 39, 1000 Ljubljana, Slovenia. Electronic address: nives.ogrinc@ijs.si.
authors: Nives
authors: N
authors: Ogrinc
mesh_terms: D063368:Balkan Peninsula; D004784:Environmental Monitoring; D009566:Nitrates / Q000032:analysis*; D009587:Nitrogen Isotopes / Q000032:analysis; D010103:Oxygen Isotopes / Q000032:analysis; D045483:Rivers / Q000737:chemistry* / Q000382:microbiology*; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D009566:Nitrates; D009587:Nitrogen Isotopes; D010103:Oxygen Isotopes; D014874:Water Pollutants, Chemical
keywords: Fecal indicators; Microbial source tracking; Nutrients; Sava River Basin; Stable isotopes