Jaroslav Černi Institute for the Development of Water Resources, Jaroslava Černog 80, Belgrade, Serbia.
Water Sci Technol. 2012;66(3):472-8. doi: 10.2166/wst.2012.179.
This paper describes the use of the dual isotope method involving δ(15)N and δ(18)O measurements of dissolved nitrates to assess the origin and fate of groundwater nitrate at the Ključ groundwater source, Serbia. A sampling campaign was conducted in September 2007 during flow conditions obtaining groundwater from observation wells and river water fed by a shallow aquifer hosted in alluvial (sandy-gravel) sediments. Nitrate isotope ratios ranged from +5.3 to +16.9‰ and δ(18)O(NO(3)) values varied from -2.3 to +5.0‰. Two major contamination sources were identified with isotopic compositions characteristic for nitrate derived from nitrification of soil organic nitrogen (+5.3 to +7.8‰ for δ(15)N) resulting in nitrate concentrations of 33.6 and 78.8 mg/L and nitrate derived from animal wastes or human sewage, e.g. via septic systems, yielding δ(15)N values of +9.9 to +11.9‰ and elevated nitrate concentrations of 31.2-245.8 mg/L. The occurrence of nitrification and denitrification was also revealed based on concentration and isotope data for dissolved nitrate.
本文描述了使用双同位素方法（涉及 δ(15)N 和 δ(18)O 测量溶解硝酸盐）来评估塞尔维亚 Ključ 地下水水源地下水硝酸盐的来源和归宿。2007 年 9 月在流量条件下进行了一次采样活动，从观测井中获取地下水，并从浅含水层补给的河流中获取河水，该含水层赋存于冲积（砂卵石）沉积物中。硝酸盐同位素比值范围为+5.3 至+16.9‰，δ(18)O(NO(3))值变化范围为-2.3 至+5.0‰。确定了两个主要的污染来源，其同位素组成特征为土壤有机氮硝化生成的硝酸盐（δ(15)N 为+5.3 至+7.8‰），导致硝酸盐浓度为 33.6 和 78.8mg/L，以及源自动物废物或人类污水（例如通过化粪池系统）的硝酸盐，其 δ(15)N 值为+9.9 至+11.9‰，硝酸盐浓度为 31.2-245.8mg/L。根据溶解硝酸盐的浓度和同位素数据，还揭示了硝化和反硝化的发生。
