利用δ^(15)N-NO_3^-和δ^(18)O-NO_3^-示踪北京城区河流硝酸盐来源  

δ^(15)N-NO_3^- and δ^(18)O-NO_3^- Tracing of Nitrate Sources in Beijing Urban Rivers

作　　者：赵庆良[1] 马慧雅 任玉芬[2] 王效科[2] 彭剑锋[1] 贺成武[2] 武俊良[2] 刘梦贞 闫苗苗[3] 

机构地区：[1]河南大学环境与规划学院,开封475004 [2]中国科学院生态环境研究中心城市与区域生态国家重点实验室,北京100085 [3]首都师范大学资源环境与旅游学院,北京100048

出　　处：《环境科学》2016年第5期1692-1698,共7页Environmental Science

基　　金：国家自然科学基金重点项目(71533005;41230633);国家自然科学基金项目(U1204403);中国科学院知识创新项目(KZCX2-EW-310)

摘　　要：为定量化识别北京城区河流硝酸盐来源,采用δ^(15)N-NO^-_3和δ^(18)O-NO^-_3双同位素示踪法对北京城区河流河水硝酸盐的氮氧稳定同位素组成进行分析,利用稳定同位素混合模型追溯北京城区河流硝酸盐来源,并评估各污染源的贡献率.结果表明:1北京河流无机氮污染以硝酸盐氮(NO^-_3-N)污染为主,且河流下游硝酸盐氮污染较为严重.2北京城区地表河流δ^(15)N-NO^-_3值范围为6.26‰~24.94‰,δ^(18)O-NO^-_3值范围为-0.41‰~11.74‰;下游δ^(15)N-NO^-_3值比上游大.3根据稳定同位素混合模型,北京河流中硝酸盐贡献率平均值分别为:粪肥及生活污水61.2%、土壤有机氮31.5%、大气沉降7.3%.In order to quantitatively identify sources of nitrate pollution in Beijing urban area and provide effective guidance for relevant departments to control the pollution of Beijing rivers,δ^15N-NO^-3and δ^18O-NO^-3isotope tracing method was used to analyze the composition of nitrogen and oxygen stable isotopes from nitrate in Beijing urban river. Besides,stable isotope mixing model was adopted to track nitrogen sources of nitrate in Beijing urban rivers and the contribution rates of respective pollution sources were evaluated. The results showed that： 1 NO^-3-N pollution was the main inorganic nitrogen pollution in Beijing rivers and pollution of downstream was more serious than that of upstream. 2δ^（15）N-NO^-3in Beijing urban surface rivers was in range of 6. 26‰-24. 94‰,while δ^18O-NO^-3ranged- 0. 41‰-11. 74‰; δ^15N-NO^-3increased from upstream to downstream along the flow of the surface water. 3 The nitrate pollution composition of Beijing rivers could be gained from the stable isotope mixing model. The average contribution rates of manure and sewage,soil nitrate and atmospheric deposition were 61. 2%,31. 5% and 7. 3%,respectively.

关 键 词：同位素示踪 δ15N-NO-3 δ18O-NO-3 硝酸盐污染 稳定同位素混合模型 贡献率 

分 类 号：X522[环境科学与工程—环境工程]