硝酸盐水质污染与污染源类型的相关性以及氮同位素的应用分析

The Correlation of Nitrate Water Pollution and its Source Type and Application Analysis of Nitrogen Isotope

摘要:

为了研究莱芜市各类污染源对硝酸盐数值贡献的大小，通过莱芜市地下水污染调查项目各类污染源水质监测结果,挑选出符合对应污染源类型的硝酸盐水质监测数据，进行数理统计，显示对硝酸盐影响数值贡献最大的污染源类型为畜禽养殖，其次为农业面源污染、固体废弃物、工业废水排放、生活污水、矿坑排水。为识别莱芜市地下水中硝酸盐的来源，选取莱芜市10处同位素采样点进行δ15N及δ18O测试，根据测试结果，δ15N值变化范围为(5.82～19.95)×10-3，δ18O值变化范围为（8.76～5.34）×103，根据采样点δ15N、δ18O值所在的值域位置及所处的水文地质条件，表明10处同位素采样点处硝酸盐来源为粪便、化肥及工业污染，部分采样点的15N及δ18O的比值大于2，基本上可证明反硝化作用的存在。

Abstract:

In order to study the contribution of all kinds of pollution sources to the nitrate value in Laiwu city, selecting the nitrate value that meet the corresponding pollution types from all kinds of sources water monitoring results of groundwater pollution investigation project in Laiwu city, it is showed that the primary pollution source is livestock, and followed by agricultural non-point source, solid waste, industrial waste water discharge, domestic sewage and mine drainage. In order to identify the source of nitrate in underground water resource in Laiwu city, by choosing 10 isotope sampling points, δ15N and δ18O have been tested. It is showed that the δ15N value is (5.82～19.95)×103, and the δ18O value is (-8.76～-5.34)×103. According to the location of δ15N and δ18O value of sampling points in the value domain and hydrogeological conditions, it is showed that the nitrate sources of the 10 isotope sampling points are manure, chemical fertilizer, industrial pollution and the specific value of 15N and δ18O of some points are larger than 2, which can basically prove the existence of denitrification.