摘要
为研究河谷型城市在春节期间大气PM_(2.5)中组分的变化和来源特征,选取2025年宝鸡市春节期间的在线监测数据(PM_(2.5)、水溶性无机离子、重金属元素以及碳质组分)进行研究。结果显示春节时由于烟花爆竹的燃放,PM_(2.5)平均质量浓度98.8μg/m^(3)略高于春节前92.4μg/m^(3),是春节后37.6μg/m^(3)的1.6倍,在1月28日(除夕夜)01:00时,PM_(2.5)浓度达到峰值285.6μg/m^(3)。春节时水溶性无机离子质量浓度按照从大到小为:SO_(4)^(2-)>NO_(3)^(-)>NH_(4)^(+)>K^(+)>Cl^(-)>Ca^(2+)>Na^(+)>Mg^(2+),春节时质量浓度增加的离子有SO_(4)^(2-)、K^(+)和Cl^(-)。大气颗粒物整体呈酸性,大气中存在较强的SO_(2)和NO_(2)的二次转化过程,春节时转化率有明显升高,且二次无机颗粒物(SNA)(NO_(3)^(-)、SO_(4)^(2-)和NH_(4)^(+))在PM_(2.5)中的占比较春节前和春节后分别增加了1.8%和3.2%。春节期间宝鸡市大气PM_(2.5)中NH_(4)^(+)、NO_(3)^(-)和SO_(4)^(2-)主要以(NH_(4))_(2)SO_(4)和NH_(4)NO_(3)形式存在。Pearson相关性分析和PMF源解析表明:Na^(+)、Mg^(2+)、Ca^(2+)、Al、Cu和Ba是主要污染物,春节时宝鸡市大气污染源有4个因子,分别是燃煤和工业源、二次无机转化源、烟花爆竹源、生物质燃烧和扬尘源,这可能与宝鸡市地形特殊,冬季逆温频发以及春节时特定时段燃放烟花爆竹有关。后向轨迹分析结果显示,春节时宝鸡市的气团轨迹主要来源于本地源,气团传输路径短,大气质量浓度受短距离传输影响大。
To study the variation and source characteristics of components in atmospheric PM_(2.5)of valley cities during the Spring Festival,online monitoring data(PM_(2.5),water-soluble inorganic ions,heavy metal elements,and carbonaceous components)of Baoji City during the Spring Festival 2025 were selected for research.The results showed that during the Spring Festival,due to the discharge of fireworks and firecrackers,the average mass concentration of PM_(2.5)was 98.8μg/m^(3),which was slightly higher than that before the Spring Festival(92.4μg/m^(3))and it was 1.6 times higher than the that after the Spring Festival(37.6μg/m^(3)).At 01:00 on January 28th(Lunar New Year's Eve),the PM_(2.5)concentration reached its peak of285.6μg/m^(3).The mass concentration of water-soluble inorganic ions during the Spring Festival,in descending order,was as follows:SO_(4)^(2-)>NO_(3)^(-)>NH_(4)^(+)>K^(+)>Cl^(-)>Ca^(2+)>Na^(+)>Mg^(2+).The ions with increased mass concentration during the Spring Festival included SO_(4)^(2-),K^(+)and Cl^(-).Atmospheric particulate matter was generally acidic,and there was a strong secondary conversion process of SO_(2)and NO_(2)in the atmosphere.The conversion rate increased significantly during the Spring Festival.Moreover,the proportion of SNA(NO_(3)^(-),SO_(4)^(2-),and NH_(4)^(+))in PM_(2.5)increased by 1.8%and 3.2%respectively,compared to those before and after the Spring Festival.During the Spring Festival in Baoji City,NH_(4)^(+),NO_(3)^(-)and SO_(4)^(2-)in atmospheric PM_(2.5)mainly exist in the form of(NH_(4))_2SO_(4)and NH_(4)NO_(3).Correlation analysis and PMF source apportionment showed that Na^(+),Mg^(2+),Ca^(2+),Al,Cu and Ba were the major pollutants.During the Spring Festival,there were four main atmospheric pollution sources in Baoji City:coal combustion and industrial sources,secondary inorganic transformation sources,fireworks and firecrackers sources,and biomass burning and dust sources.This may be related to Baoji's unique topography,frequent winter temperature inversions,and fireworks discharge during specific periods during the Spring Festival.Backward trajectory results indicated that air mass trajectories in Baoji City during the Spring Festival mainly originated from nearby cities,with short transmission paths,resulting in significant impacts of short-distance transmission on atmospheric concentration levels.
作者
刘丽霞
王维
LIU Lixia;WANG Wei(Baoji Environmental Monitoring Center Station,Baoji,Shaanxi 721006,China)
出处
《四川环境》
2025年第6期11-21,共11页
Sichuan Environment
基金
宝鸡市区县大气环境监测能力提升项目(2023610399Q1-40003)。
