GeoActa Special Publication 1
2008
Acquisto online |
GeoActa
an international Journal of Earth Sciences
|
|
Barbara Nisi
Department of Earth Sciences, University of Florence, Via G. La Pira, 4, 50121 Florence (Italy)
|
Orlando Vaselli, Antonella Buccianti
Department of Earth Sciences, University of Florence, Via G. La Pira, 4, 50121 Florence (Italy)CNR Institute of Geosciences and Earth Resources, Via G. La Pira, 4, 50121 Florence (Italy)
|
Steven R. Silva
U.S. Geological Survey, Middlefield Rd. 345, Menlo Park, CA 94025 (USA)
|
|
Sources of nitrate in the Arno River Waters: constraints from d15N and d18O
|
|
|
|
PDF (414 KB)
|
Abstract
Running waters in anthropogenically affected areas are susceptible to nitrate contamination. Source identification is a fundamental step for the development of effective remediation. Previous studies pointed to pollution by nitrogen-bearing contaminants in the Arno Basin. In this paper, eleven surface water samples have been analysed for main and trace components and 15N/14N and 18O/16O ratios, with the aim of identifying for the first time the origin of nitrate in the Arno River Basin so that further investigations can appropriately be designed. d18O(NO3) and d15N(NO3) values have allowed to hypothesise the main sources of nitrate, as follows: i) mineralized fertilizer, ii) soil-organic nitrogen, iii) manure and septic waste. The anomalously high d15N and d18O values in the Chiana (d15N=24.9 and d18O=15.5) and Usciana tributaries (d15N=30.1 and d18O=7.2) show a low probability of belonging to the same population as that of the other samples and can be related to denitrification process of nitrate from animal waste/sewage and/or an industrial process (e.g. tanneries).
Keywords: Italy, Arno River, Nitrate, Nitrogen and Oxygen Isotopes, Environmental Geochemistry
|
|
|