The Po river basin, approximately 74,000 km2, covers most part of Northern Italy, about a quarter of the national territory. Over 20 million inhabitants live in this area, which is interested by intense urbanization, industrial and agricultural a ctivities. This in turn means that the River Po is potentially affected bycontaminants that can be transferred toward the Adriatic Sea. It is therefore important to evaluate the quality and to monitor the compositional evolution of its water, taking in consideration major and trace elements as well as isotopic compositions. In the framework of a cooperative project between the Univ. Ferrara and the Helmhotz Center for Environmental Research UFZ of Halle (Germany) we carried out a wide range of different isotopic analyses including: a) 18O/16O and 2H/1H that give indication on the zone where most of the meteoric recharge occurs, and that trace the salinization due to mixing with sea water occurring in the terminal part of the River Po Delta; b) 13C/12C and 15N/14N that give indications on the origin of nutrients th at induce eutrophication processes. In particular, the carbon isotopic analysis provides information on the interaction processes between water and carbon dioxide and, therefore, on the (natural and/or anthropogenic) origin of this component. The isotopic composition (δ13C) of Dissolved Inorganic Carbon (DIC) in the Po River varies, and appears to be different at distinct distance from the River source. We observed a δ13C range of variation between 11,5‰ and 4,4 ‰, with the lower value recorded in the site at the confluence with the Ticino river. Emphasis is also given to the δ15N , and preliminary data using the Denitrifier Method (Sigman et al. 2001; Anal. Chem. 73, 4145 – 4153), show the following δ15N range of variation: 2,2 and +12,1. These data compared with data from the literature (Sacchi et al. 2013 and references therein; Applied Geochemistry), highlight nitrate contamination from several sources, including synthetic fertilizers from agricultural crops, manure from zootechnical activities, as well assewage components.
The Geochemical composition of Po River Water, with emphasis to the C-N-O-H isotopic signature
MARCHINA, Chiara;BIANCHINI, Gianluca;
2013
Abstract
The Po river basin, approximately 74,000 km2, covers most part of Northern Italy, about a quarter of the national territory. Over 20 million inhabitants live in this area, which is interested by intense urbanization, industrial and agricultural a ctivities. This in turn means that the River Po is potentially affected bycontaminants that can be transferred toward the Adriatic Sea. It is therefore important to evaluate the quality and to monitor the compositional evolution of its water, taking in consideration major and trace elements as well as isotopic compositions. In the framework of a cooperative project between the Univ. Ferrara and the Helmhotz Center for Environmental Research UFZ of Halle (Germany) we carried out a wide range of different isotopic analyses including: a) 18O/16O and 2H/1H that give indication on the zone where most of the meteoric recharge occurs, and that trace the salinization due to mixing with sea water occurring in the terminal part of the River Po Delta; b) 13C/12C and 15N/14N that give indications on the origin of nutrients th at induce eutrophication processes. In particular, the carbon isotopic analysis provides information on the interaction processes between water and carbon dioxide and, therefore, on the (natural and/or anthropogenic) origin of this component. The isotopic composition (δ13C) of Dissolved Inorganic Carbon (DIC) in the Po River varies, and appears to be different at distinct distance from the River source. We observed a δ13C range of variation between 11,5‰ and 4,4 ‰, with the lower value recorded in the site at the confluence with the Ticino river. Emphasis is also given to the δ15N , and preliminary data using the Denitrifier Method (Sigman et al. 2001; Anal. Chem. 73, 4145 – 4153), show the following δ15N range of variation: 2,2 and +12,1. These data compared with data from the literature (Sacchi et al. 2013 and references therein; Applied Geochemistry), highlight nitrate contamination from several sources, including synthetic fertilizers from agricultural crops, manure from zootechnical activities, as well assewage components.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
