利用氮氧同位素定量识别地下水中硝酸盐来源

为研究西安市浅层地下水中硝酸盐来源,采集秦岭山前、市郊、市区地下水样,分析其常规化学指标和氮氧同位素,利用硝酸盐氮氧双同位素和Iso Source同位素模型,确定地下水中硝酸盐的主要来源及各个来源的贡献率。研究结果表明:西安市区的硝酸盐主要来源于生活污水粪肥,约占55%~75%;郊区的硝酸盐主要来源是土壤有机氮和生活污水粪肥,分别占37%~55%,36%~58%;而山前地区的硝酸盐主要来源于土壤有机氮转化,约占77%~96%。

Quantitative identification of nitrate source in groundwater by using nitrogen and oxygen isotope

In order to study the nitrate source in shallow groundwater of Xi'an,the paper collected several samples of acquisition underground water from piedmont area of Qingling, suburban, urban of Xi'an,analyzed the conventional chemical index and nitrogen oxygen isotopes. It used the nitrogen and oxygen isotope model of nitrate,Isosource model to identify the main sources of nitrate in groundwater and the ratio every source.The results show that in urban area of Xi'an,the nitrate in groundwater is mainly from animal waste water and sewage, which accounts for from 55% to 75%. In the suburban area, the nitrate in groundwater is mainly from organic nitrogen of soil, animal waste and sewage which is from 37% to 55% and from 36% to 58% respectively. In the piedmont area of Qingling, the nitrate in groungwater is mainly from soil organic nitrogen and the rate is from 77% to 96%.