Characterization of groundwater dynamics and contamination in an unconfined aquifer using isotope techniques to evaluate domestic supply in an urban area

In the urban area of Rio Cuarto groundwater is used for domestic supply. The objective of the current research was to investigate the water dynamics and nitrate contamination in an unconfined aquifer system of Rio Cuarto River basin. Stable isotopes of water (δ18O and δ2H) and nitrate (δ15N–NO3 and δ18O–NO3) were used and combined with conventional chemical techniques and mixing modelling approaches to determine the recharge areas and identify the main origin of nitrate pollution. More enriched water isotope values were recorded in Rio Cuarto city than in the piedmont and mountains indicating local recharge for well batteries 2 and 3. The well battery 1 and the infiltration gallery showed more negative isotopic values, demonstrating a strong influence by the recharge from the piedmont sector (impoverished groundwater). The δ15N–NO3 values and the Bayesian modeling showed that the dominant nitrate contamination source in the urban area is the on-site sanitation systems whereas in the peri-urban area nitrate contamination originates mostly from animal wastes. Both sources supply the aquifer with anthropogenic organic matter (>50%). The highest δ15N–NO3 values were correlated with low dissolved oxygen values, indicating the occurrence of denitrification processes in some places. High NO3 ions in the rural sector were attributed to the application of fertilizers and consequent nitrification processes. The samples from Rio Cuarto river located upstream of the Rio Cuarto City and close to the infiltration gallery showed the highest input from fertilizers (~40%), due to surrounding agricultural fields. The municipal well batteries showed good water quality (freshwater of low to extremely low nitrate concentration) which is linked to the high hydraulic conductivity of the aquifer that increases its capacity to dilute the contaminants. These results will be useful for local water administrators to improve water management.Fil: Blarasin, Mónica Teresa. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Geología; ArgentinaFil: Matiatos, I.. International Atomic Energy Agency (iaea); AustriaFil: Cabrera, A.. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Geología; ArgentinaFil: Lutri, Veronica Florencia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Giacobone, Daniela Beatriz. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Bécher Quinodóz, Fátima Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Matteoda, E.. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Geología; ArgentinaFil: Eric, C.. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Geología; ArgentinaFil: Felizzia, J.. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Geología; ArgentinaFil: Giuliano Albo, J.. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Geología; Argentin

Energy-Dispersive Total-Reflection Resonant Inelastic X-ray Scattering as a Tool for Elemental Speciation in Contaminated Water

This work presents a state-of the-art analytical methodology, by which chemical state information on metallic elements is obtained for liquid samples in a fast and simple manner. This method overcomes limitations of conventional X-ray techniques, such as X-ray absorption spectroscopy, by applying resonant inelastic X-ray scattering under total reflection geometry (TRIXS). TRIXS is particularly applicable for the analysis of small quantity of liquid samples deposited on polished reflectors. This feature is relevant for the chemical speciation of metallic trace elements contained in water samples, since the degree of their toxicity depends crucially on the concentration of specific chemical species included. The analytical merits of the proposed methodology were studied at Elettra Sincrotrone Trieste and at the Brazilian Synchrotron Light Laboratory. Contaminated water samples with low concentration of different chromium and manganese compounds were measured. Results prove the analytical potential of the TRIXS technique in characterizing different chemical species of metallic elements in water samples.Fil: Robledo, José Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Leani, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Karydas, Andreas G.. International Atomic Energy Agency; Austria. National Center for Scientific Research “Demokritos”. Institute of Nuclear and Particle Physics; GreciaFil: Migliori, A. International Atomic Energy Agency; AustriaFil: Pérez, Carlos A.. Brazilian Synchrotron Light Source; BrasilFil: Sanchez, Hector Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentin