澜沧江水系氮磷污染及硝酸盐来源解析  

Analysis of Nitrogen and Phosphorus Pollution and Nitrogen Sources in the Lancang River

作　　者：郭树芳 陈安强[1] 习斌 居学海 黄宏坤 刘建香[1] 毛妍婷[1] 郭云周[1] 雷宝坤[1] GUO Shu-fang;CHEN An-qiang;XI Bin;JU Xue-hai;HUANG Hong-kun;LIU Jian-xiang;MAO Yan-ting;GUO Yun-zhou;LEI Bao-kun(Agricultural Environment and Resources Institute,Yunnan Academy of Agricultural Sciences,Kunming 650201,China;Rural Energy and Environment Agency,Ministry of Agriculture and Rural Affairs,Beijing 100125,China)

机构地区：[1]云南省农业科学院农业环境资源研究所,昆明650201 [2]农业农村部农业生态与资源保护总站,北京100125

出　　处：《环境科学》2022年第12期5491-5498,共8页Environmental Science

基　　金：云南农业农村绿色发展保障技术体系专项(530000210000000016943);第二次全国污染源普查项目(2110399);云南省重大科技专项计划项目(202102AE090011);国家自然科学基金项目(31960635)。

摘　　要：有效控制氮磷输入是水质持续改善的关键因素.为识别澜沧江水系水体中氮磷浓度、氮污染物来源及其空间分布特征,在澜沧江流域开展了干流和支流水样的采集,分析流域不同区域水体氮磷浓度,并利用氮氧同位素技术结合稳定同位素SIAR模型,解析了水系不同区域氮素来源及其贡献率.结果表明:①澜沧江水系氮浓度偏低,ρ(TN)分布在0.34~4.18 mg·L^(-1)之间,从上游至下游有升高趋势;ρ(TP)分布在0.11~2.34 mg·L^(-1)之间.②澜沧江水系的δ^(15) N-NO_(3)-和δ^(18) O-NO_(3)-值分别分布在-5‰~5‰和-16‰~16‰之间,主要落在降雨及肥料和土壤氮范围内,主要存在硝化作用.③澜沧江干流中土壤氮和化学肥料的贡献率分别为37.67%~42.41%和34.22%~38.56%,粪便和生活污水占15.01%~20.79%,大气沉降仅占4.49%~7.32%.中游支流和下游支流中土壤氮的贡献明显高于化学肥料,土壤氮的贡献率达53.97%~61.57%,化学肥料占33.37%~38.30%,而大气沉降、粪便和生活污水的贡献率较低.研究分析了澜沧江水系上、中和下游干流和支流的氮素来源,为该区域的水质管理和污染源治理提供了依据.The effective control of nitrogen(N)and phosphorus(P)input is a key factor in the improvement of water quality.In order to identify the concentrations of N and P and the sources of N pollutants and their spatial distribution characteristics in the Lancang River,water samples of Lancang mainstream and major tributaries were collected,and the N sources and contribution rates were analyzed by using nitrogen and oxygen isotope technology combined with a stable isotope SIAR model.The results showed that:①the N concentrations in the Lancang River were low,and the TN concentrations ranged from 0.34 to 4.18 mg·L^(-1) and increased from upstream to downstream;the TP concentrations ranged from 0.11 to 2.34 mg·L^(-1).②δ^(15)N-NO_(3)-andδ^(18)O-NO_(3)-in the Lancang River were in the range of-5‰-5‰and-16‰-16‰,respectively,and mainly fell in the range of rainfall,fertilizer,and soil N.The nitrification process occurred mainly in the Lancang River.③The contribution rates of soil N and chemical fertilizer in the mainstream of the Lancang River ranged from 37.67%-42.41%and 34.22%-38.56%,respectively,manure and sewage accounted for 15.01%-20.79%,and atmospheric deposition accounted for only 4.49%-7.32%.The contribution rates of soil N of 53.97%-61.57%in tributaries in the middle and downstream reaches were higher than that of chemical fertilizer(33.37%-38.30%),whereas the contributions of atmospheric deposition and manure and sewage were low.This study analyzed the N source of the Lancang mainstream and tributaries in the upper,middle,and lower reaches,providing a theoretical basis for water quality management and pollution source control in the Lancang River basin.

关 键 词：澜沧江流域 NO_(3)--N 氮同位素 氧同位素 来源解析 

分 类 号：X522[环境科学与工程—环境工程]