基于氮氧同位素的入海河流硝酸盐来源差异化分析  

Analysis of Nitrate Sources in Different Rivers Flowing into the Sea Based on Nitrogen and Oxygen Isotopes

作　　者：辛卓航 常鹏娟 刘志红[1] 宋长春 XIN Zhuo-hang;CHANG Peng-juan;LIU Zhi-hong;SONG Chang-chun(Department of Hydraulic Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学水利工程系,大连116024

出　　处：《环境科学》2025年第3期1371-1381,共11页Environmental Science

基　　金：国家自然科学基金项目(U21A20155,52279007,52009015)。

摘　　要：陆域氮通量输入是河口氮负荷的首要来源,引发富营养化和低氧等生态环境问题,系统识别入海河流的氮来源是河口氮管控的前提.基于对环渤海辽宁省、河北省的12条入海河流179个点位的氮氧同位素特征分析,系统识别了河流的硝酸盐来源,并结合稳定同位素(SIAR)模型定量计算各污染源对河流硝酸盐的贡献率.结果表明,研究区硝酸盐的转化主要以硝化作用为主.对12条河流,动物粪便及污水的贡献率范围为13.9%~90.1%,土壤氮的贡献率范围为4.3%~54.0%.此外,沧州市廖家洼河、宣惠河和南排河的农业化肥贡献率较高,为25.2%~64.4%.总体而言,这12条河流的氮通量受人类活动干扰强度大,且不同河流的硝酸盐主要来源存在差异,应有针对性地采取差异化的氮污染源管控措施.The nitrogen flux from terrestrial input is the primary source of nitrogen load in estuarine areas,leading to ecological issues,such as coastal eutrophication and hypoxia.Systematically identifying the nitrogen sources from different rivers draining into the sea is a prerequisite for controlling the nitrogen pollution in estuarine areas.Based on the nitrogen and oxygen isotopes of 179 sampling sites across 12 rivers in Liaoning and Hebei Provinces,the nitrate sources of different rivers were systematically identified.Moreover,the stable isotope analysis in the R(SIAR)model was employed to quantitatively calculate the contribution rates of various pollution sources to river nitrate.The results indicated that nitrification was the primary process of nitrate transformation.For all 12 rivers,the contribution rate of animal manure and sewage ranged from 13.9%to 90.1%and that of soil nitrogen ranged from 4.3%to 54.0%.Additionally,for the Liaojiawa River,Xuanhui River,and Nanpai River in Cangzhou City,agricultural fertilizers were observed to have relatively high contribution rates,ranging from 25.2%to 64.4%.Overall,the nitrogen loads in these 12 rivers were highly disturbed by anthropogenic activities and the primary sources of nitrate varied among different rivers.Therefore implementing targeted and differentiated control measures in watershed nitrogen control and management is important.

关 键 词：环渤海河流 氮氧同位素 硝酸盐来源 稳定同位素(SIAR)模型 贡献率 

分 类 号：X522[环境科学与工程—环境工程]