近十年来黄河中下游河水硝酸盐含量和来源变化及影响因素分析  

Decadal dynamics of nitrate content,source variations and influencing factors in the middle and lower reaches of the Yellow River

作　　者：陈欣 冯震江 徐俏 夏瑞[2] 马翠梅 夏星辉[1] CHEN Xin;FENG Zhenjiang;XU Qiao;XIA Rui;MA Cuimei;XIA Xinghui(School of Environment,Beijing Normal University,Beijing 100875;Chinese Research Academy of Environmental Sciences,Beijing 100012;National Center for Climate Change Strategy and International Cooperation,Beijing 100035)

机构地区：[1]北京师范大学环境学院,北京100875 [2]中国环境科学研究院,北京100012 [3]国家应对气候变化战略研究和国际合作中心,北京100035

出　　处：《环境科学学报》2025年第3期241-250,共10页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金重点项目(No.52039001);黄河流域生态保护和高质量发展联合研究项目(No.2022-YRUC-01-0202)。

摘　　要：黄河流域生态保护和高质量发展是国家重大发展战略,但黄河水质低于全国平均水平,入海总氮浓度高于其它大型河流.硝酸盐作为河流中主要的含氮化合物,探究河流硝酸盐浓度和来源的时空变化,评价流域环境管理措施对河流硝酸盐的影响,对缓解河流氮污染具有重要作用.然而,黄河中下游河水硝酸盐浓度和来源及其在环境管理措施实施后的时空变化尚不清楚.因此,本研究分析了2011、2023和2024年黄河中下游流域河水硝酸盐的浓度和同位素组成(Δ^(17)O、δ^(15)N和δ^(18)O-NO_(3)^(-)),结合δ^(15)N/Δ^(17)O-NO_(3)^(-)稳定同位素SIAR模型,探讨了河水硝酸盐浓度和来源的时空变化特征,分析了流域环境管理措施的影响.结果表明,近10年来,黄河中下游河水硝酸盐浓度呈下降趋势,平均浓度由4.4 mg·L^(-1)降至2.6 mg·L^(-1).黄河水系硝酸盐浓度的变化与流域生态环境管理措施的实施密切相关,对化肥施用量的严格控制、水土流失的治理以及污水处理效率的提高减少了入河氮负荷.而且,各个污染来源对黄河中下游河水硝酸盐的相对贡献发生了变化,来自土壤氮和化肥的贡献由约70%降低至约50%,来自污水粪肥的贡献由约30%增加至约50%,说明未来应在继续治理水土流失等面源污染的基础上,加强对农村生活污水、畜禽养殖废水等的治理和控制.研究结果为进一步调整和制定削减河流氮污染的政策提供了科学依据,对于提升黄河水质、改善渤海富营养化污染现状等具有重要意义.The ecological protection and high-quality development of the Yellow River Basin is an important national development strategy.Despite ongoing efforts,the water quality of the Yellow River remains below the national average,with its total nitrogen concentration discharging into the sea exceeding that of other major rivers.Given the dominance of nitrate in riverine nitrogen species,understanding its spatiotemporal patterns,source dynamics,and responses to environmental governance is critical for effective pollution control.This study addresses critical knowledge gaps regarding decadal nitrate evolution in the middle-lower Yellow River(MLYR)through an integrated analysis of nitrate isotopes(Δ^(17)O,δ^(15)N,andδ^(18)O-NO_(3)-)and hydrological monitoring data from 2011 to 2024.Our findings reveal nitrate concentrations decreased from 4.4 mg·L^(-1)to 2.6 mg·L^(-1)over the study period,demonstrating significant improvements in nitrogen management.This reduction is closely associated with ecological and environmental management measures,including stricter controls on fertilizer application,enhanced soil erosion management,and improved wastewater treatment efficiency.Dual isotope Bayesian mixing models usingδ^(15)N/Δ^(17)O-NO_(3)-traces indicate fundamental shifts in various pollution sources:soil nitrogen and fertilizers decreased from approximately 70%to 50%,while sewage and manure increased from approximately 30%to 50%.Our results underscore the urgent need for targeted controls of rural domestic sewage and livestock breeding wastewater,alongside continued mitigation of non-point source pollution.This study provides critical insights for refining and formulating policies to control nitrate pollution,ultimately contributing to improved water quality in the Yellow River and alleviating eutrophication pressures in the Bohai Sea.

关 键 词：黄河流域 硝酸盐 源解析 氮氧同位素 

分 类 号：X522[环境科学与工程—环境工程]