浦阳江中下游氮分布特征及来源解析  

Distribution patterns and source analysis of nitrogen in middle and lower reaches of the Puyang River

作　　者：张毅敏 桂浩翔 陈婷 张志伟 高月香 于江华[1] ZHANG Yimin;GUI Haoxiang;CHEN Ting;ZHANG Zhiwei;GAO Yuexiang;YU Jianghua(College of Environmental Science and Engineering,Nanjing University of Information Science&Technology,Nanjing 210044,China;Nanjing Institute of Environmental Science,MEE,Nanjing 210042,China;School of Geography and Planning University,Ningxia University,Yinchuan 750021,China;School of Environment,Hohai University,Nanjing 210098,China)

机构地区：[1]南京信息工程大学环境科学与工程学院,江苏南京210044 [2]生态环境部南京环境科学研究所,江苏南京210042 [3]宁夏大学地理科学与规划学院,宁夏银川750021 [4]河海大学环境学院,江苏南京210098

出　　处：《水资源保护》2024年第6期206-214,共9页Water Resources Protection

基　　金：全国第二次污染源普查农业源入水污染负荷核算项目(2110399);江苏省研究生科研与实践创新计划项目(SJCX23_0413)。

摘　　要：基于2022—2023年绍兴市浦阳江中下游水体中TN、NO_(3)^(-)、NO_(2)^(-)和NH_(4)^(+)质量浓度数据,分析了氮污染的主要形态、质量浓度和负荷的空间分布,并通过正向溯源法(现场监测、产排污系数法、SWAT模型)及反向溯源法(氮氧稳定同位素方法)探析了氮污染来源。结果表明:地表水氮污染以硝态氮为主,旱季TN质量浓度显著高于雨季(p<0.05),城镇及农业分布地区氮素指标质量浓度高于其他区域;2022年流域内TN负荷以生活源(58.7%)为主,其次为农业源(39.5%);TN高负荷地区主要分布在人口密集的浦阳江下游干流沿岸以及农田分布较多的子流域;TN负荷与降水量之间存在较强的正相关性(p<0.01),并在雨季的6月达到最高值;城市化程度和生活区集群对δ^(15)N-NO^(3)^(-)值有较大影响,流域硝酸盐来源以生活污水为主(平均占比54.5%);不同支流的硝酸盐来源也存在差异,土地利用类型及城镇化水平是主要驱动因素。Based on the data of total nitrogen(TN),nitrate(NO_(3)^(-)),nitrite(NO_(2)^(-)),and ammonium(NH_(4)^(+))mass concentrations in the middle and lower reaches of the Puyang River in Shaoxing City from 2022 to 2023,this study analyzes the primary forms,concentration levels,and spatial distribution of nitrogen pollution.The sources of nitrogen pollution were investigated by using both forward tracing methods(field monitoring,emission coefficient approach,and SWAT model)and reverse tracing methods(nitrogen and oxygen stable isotope methods).The results indicate that nitrogen pollution in surface water is predominantly in the form of nitrate nitrogen,with TN mass concentrations in the dry season significantly higher than that in the rainy season(p<0.05).Higher nitrogen levels were observed in urban and agricultural areas compared to other regions.In 2022,domestic sewage sources accounted for the largest share of TN load(58.7%),followed by agricultural sources(39.5%).Areas with high TN load were concentrated along the densely populated lower reaches of the Puyang River and in sub-watersheds with extensive farmland.There was a strong positive correlation between TN load and precipitation(p<0.01),reaching the highest valuein June during the rainy season.The degree of urbanization and residential clustering significantly influenced δ^(15)N-NO_(3)^(-) values,with domestic sewage identified as the primary source of nitrate in the watershed(averaging 54.5%).The sources of nitrate in different tributaries also vary,driven largely by land use types and urbanization levels.

关 键 词：氮负荷 硝酸盐来源 稳定同位素 SWAT模型 浦阳江流域 

分 类 号：X52[环境科学与工程—环境工程]