Orlando Vaselli Antonella Buccianti Steven R. Silva Barbara Nisi 2005 <p><span>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&nbsp;¹⁵N/¹⁴N and&nbsp;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.&nbsp;</span><span>d</span><span>¹⁸O(NO₃)and&nbsp;</span><span>d</span><span>¹⁵N(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&nbsp;</span><span>d</span><span>¹⁵N and&nbsp;</span><span>d</span><span>¹⁸O values in the Chiana (</span><span>d</span><span>¹⁵N=24.9&permil; and&nbsp;</span><span>d</span><span>¹⁸O=15.5&permil;) and Usciana tributaries (</span><span>d</span><span>¹⁵N=30.1&permil; and&nbsp;</span><span>d</span><span>¹⁸O=7.2&permil;) 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).</span></p> application/pdf en GeoSed Sources of nitrate in the Arno River waters: Constraints from d¹⁵N and d¹⁸O article