Relación entre 18O del agua y el contenido de NO3, como herramienta metodológica para analizar su concentración en un arroyo del sudeste bonaerense

CALVI, CAROLINA; MARTINEZ, DANIEL E.; DAPEÑA, CRISTINA

Puerto Madryn

Otro; IV Reunión Argentina de Geoquímica de la Superficie; 2016

IPEEC-CONICET, CESIMAR-CONICET, UTN FRCH

Nitrate pollution of surface water is a global problem producing human health and environmental consequences. The study area includes La Ballenera creek located in the SE of the Buenos Aires province. In this work a relationship is established between changes in 18O and NO3 in superficial water. During 2013-2014 were taken 127 samples on the bridge over Route 77 (SLBA) and 51 on the bridge over Route 11 (SLBB). Nitrate concentrations were measured in the range of 2 -79.6 mg/L. In winter-spring intervals (1 and 3), there are variable nitrate and cycles of 18O, which start from -5.5 ? in SLBA to more enriched values (-3 ?) in SLBB. In summer-autumn 2014 (2) in SLBA  18O values are close to -5.5 ? and NO3 levels exceed 45 mg/L; while in SLBB 18O values are more variable than in SLBA and nitrate average is 6 mg/L. The analogous 18O value (-5.5 ?) of superficial water and the aquifer confirm the great influence of groundwater in that period in relation to 1 and 3.