西安市大气降水的主要化学组分及其来源  

Main Chemical Components in Atmospheric Precipitation and Their Sources in Xi’an

作　　者：周东 黄智浦 李思敏 王森[1,3] 牛振川 熊晓虎[2] 冯雪 ZHOU Dong;HUANG Zhi-pu;LI Si-min;WANG Sen;NIU Zhen-chuan;XIONG Xiao-hu;FENG Xue(Key Laboratory of Surface Processes and Environmental Carrying Capacity in Shaanxi Provincial,College of Urban and Environmental Sciences,Northwestern University,Xi'an 710127,China;StateKey Laboratory of Loess and Quaternary Geology,Institute ofEarth Environment,Chinese Academy of Sciences,Xian 710061,China;Urban Ecosystem Observation and Research Station in Xi'an,Xi'an 710127,China;National Field Observation and Research Station of Regional Eco-Environmental Change and Comprehensive Management in Guanzhong Plain,Xi'an 710061,China;Institute of Earth Environment Innovation in Xi'an,Xi'an 710061,China)

机构地区：[1]西北大学城市与环境学院,陕西省地表过程与环境承载力重点实验室,西安710127 [2]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710061 [3]陕西西安城市生态系统定位观测研究站,西安710127 [4]陕西关中平原区域生态环境变化与综合治理国家野外科学观测研究站,西安710061 [5]西安地球环境创新研究院,西安710061

出　　处：《环境科学》2023年第6期3142-3151,共10页Environmental Science

基　　金：中国科学院战略性先导科技专项(XDA23010302);国家自然科学基金项目(42173082,41773141,41573136)。

摘　　要：为认识西安市大气降水主要化学组分的现状,对2019年西安市市区和郊区大气降水样品的pH值、电导率、水溶性离子和重金属的质量浓度、湿沉降通量和来源进行了研究.结果表明,西安市冬季大气降水pH、电导率、水溶性离子和重金属浓度均高于其它季节.降水中主要的水溶性离子为Ca^(2+)、NH_(4)^(+)、SO_(4)^(2-)和NO_(3)^(-),其之和占总离子浓度的(88.5±2.8)%;市区和郊区主要重金属是Zn和Fe、Zn和Mn,其之和分别占总金属浓度的(54.0%±3)%和(47.0%±8)%.市区和郊区降水中水溶性离子的湿沉降通量分别为(253.2±58.4)mg·(m^(2)·month)^(-1)和(241.9±61.1)mg·(m^(2)·month)^(-1),呈现出冬季高于其他季节的特点;重金属的湿沉降通量分别为(86.2±37.5)mg·(m^(2)·month)^(-1)和(88.1±37.4)mg·(m^(2)·month)^(-1),季节差异较小.PMF源解析表明,市区和郊区降水中水溶性离子主要来源于燃烧源(57.5%和32.32%),其次是机动车源(24.4%和17.2%)和扬尘源(18.1%和27.0%),郊区降水中离子还受到了当地农业(11.1%)的影响.市区和郊区降水中重金属主要来源于工业源(51.8%和46.7%);燃煤和机动车混合源在冬季贡献率比夏季分别高10.7%和6.1%.In order to understand the current status of main chemical components of atmospheric precipitation in Xi'an,the pH,electrical conductivity,mass concentration of water-soluble ions and heavy metals,wet deposition fluxes,and their sources in precipitation samples in urban and suburban areas of Xi'an in 2019 were studied.The results showed that the pH,conductivity,water-soluble ions,and heavy metals in precipitation in Xi'an in winter were higher than those in other seasons.The main water-soluble ions in precipitation were Ca^(2+),NH_(4)^(+),SO_(4)^(2-),and NO_(3)^(-),and the sum of these ions accounted for(88.5%±2.8)% of the total ion concentration in urban and suburban areas.The main heavy metals were Zn,Fe,and Zn and Mn;their sum accounted for(54.0%±3)% and(47.0%±8)% of the total metal concentration.The wet deposition fluxes of water-soluble ions in precipitation in urban and suburban areas were(253.2±58.4)mg·(m^(2)·month)^(-1)and(241.9±61.1)mg·(m^(2)·month)^(-1),respectively.They showed higher values in winter than those in other seasons.The wet deposition fluxes of heavy metals were(86.2±37.5)mg·(m^(2)·month)^(-1)and(88.1±37.4)mg·(m^(2)·month)^(-1),respectively,with little seasonal difference.The source analysis using PMF showed that the water-soluble ions in urban and suburban precipitation mainly came from combustion sources(57.5% and 32.32%),followed by motor vehicles(24.4% and 17.2%)and dust sources(18.1% and 27.0%).The ions in suburban precipitation were also affected by local agriculture(11.1%).Heavy metals in precipitation in urban and suburban areas mainly came from industrial sources(51.8% and 46.7%),and the contribution rate of coal and motor vehicle mixed sources in winter was 10.7% and 6.1% higher than that in summer,respectively.

关 键 词：大气降水 水溶性离子 重金属 正交矩阵因子分解模型 湿沉降通量 来源解析 

分 类 号：X131[环境科学与工程—环境科学]