摘要
采用硝酸盐δ15N和δ18O相结合的方法对石家庄市地下水中的NO3-来源、反硝化作用的发生进行了识别,并结合氚分布特征对其污染深度进行了讨论.结果表明,该区地下水中硝酸盐的δ15N/δ18O比值大约是2∶1,说明发生了一定程度的反硝化作用;反硝化作用后硝酸盐的δ15N和δ18O值的范围分别为4.6‰-13.9‰和1.9‰-7.8‰,通过校正分析,判定其NO3-主要来源于当地的化肥和动物粪肥;同时NO3-随深度的分布关系表明该区的污染范围仅局限于浅部,污染深度〈150 m,这与氚含量所反映的现代水循环深度相对应.
A dual isotope method of measuring both the δ15N and δ18O in NO3- was used to discriminate the origin of nitrate and its denitrification in groundwater in Shijiazhuang. Furthermore, the contaminated depth was discussed by tritium. The results show that the ratio of δ15N/δ18O in NO3- is close to 2 ： 1, indicating that some denitrification is occurring in this area ; The value of δ15N and - δ18O in NO3- after deuitrification are 4.6‰-13.9‰ and 1.9‰-7.8‰ respectively, which indicates that the main source of nitrate in groundwater are local fertilizer and Animal Waste/Septic Systems. The relationship between NO3- concentration and the depth also shows that the pollution depth is less than 150 m, which is corresponding to the depth of active recharge zone indicated by tritium content. This implies the shallow aquifer above 150m is vulnerable to pollution.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2009年第6期1602-1607,共6页
Environmental Science
基金
国家自然科学基金项目(40472125)
国土资源部重大创新项目(1212010734411)
