摘要
为了研究大连市大气细颗粒物(PM_(2.5))的污染特征及成因,本研究对2021年6月-2022年5月在大连市采集的120个PM_(2.5)有效滤膜样品进行水溶性离子、碳质组分和无机元素的含量测定.结果表明,大连市PM_(2.5)年均质量浓度为(33.2±28.9)μg·m^(-3),冬季浓度最高,夏季浓度最低.PM_(2.5)中水溶性离子、碳质组分、无机元素的年均浓度分别为(18.7±20.5)、(6.2±4.5)、(0.8±0.5)μg·m^(-3).正定矩阵分解模型(PMF)的结果表明,PM_(2.5)的污染源贡献比例从大到小依次为二次硝酸盐(44.4%)、二次硫酸盐(19.5%)、燃煤源(10.7%)、交通源(10.6%)、工业源(6.1%)、生物质燃烧(4.6%)和海盐&扬尘(4.0%).采样期间,有9 d PM_(2.5)的日均浓度超过GB 3095-2012中24 h平均二级浓度限值(75μg·m^(-3)),系统聚类分析的结果表明,这9 d的污染特征可以分为3类.Ι型污染天气占污染总天数的66.7%,以二次硝酸盐为主要源,贡献率达到82.1%,主要来自西部和南部源区.Ⅱ型污染天气占总天数的22.2%,表现为二次硝酸盐(51.0%)为主,交通源(5.3%)为辅的混合污染特征,主要来自北部和西部的源区;与Ⅰ型相比,燃煤源和二次硫酸盐的贡献率明显增高.Ⅲ型污染天气占总天数的11.1%,主要由燃煤源和二次硫酸盐贡献,以大连以北的污染排放贡献为主.
In order to study the pollution characteristics and the causes of atmospheric fine particulate matter(PM_(2.5))in Dalian,the present study analyzed the contents of water-soluble ions,carbonaceous components and inorganic elements of 120 PM_(2.5)samples collected from June 2021 to May 2022.The results showed that the average annual concentration of PM_(2.5)was(33.2±28.9)μg·m^(-3),with the highest concentration in winter and the lowest in summer.The annual average concentrations of water-soluble ions,carbonaceous components,and inorganic elements in PM_(2.5)were(18.7±20.5),(6.2±4.5),(0.8±0.5)μg·m^(-3),respectively.The results of positive definite matrix factorization(PMF)showed that the largest source contributor of PM_(2.5)was secondary nitrate(44.4%),followed by secondary sulfate(19.5%),coal source(10.7%),transportation source(10.6%),industrial source(6.1%),biomass combustion(4.6%),and sea salt&dust(4.0%).During the sampling period,there were 9 days when the daily average PM_(2.5)concentration exceeded the 24-hour mean secondary concentration limit(75μg·m^(-3))in GB 3095-2012,The results of systematic clustering analysis showed that the pollution characteristics of these 9 days could be divided into three categories.Type Ⅰ pollution weather accounted for 66.7%of the total pollution days,and secondary nitrate was the main source with a contribution rate of 82.1%,which mainly came from the western and southern source regions.The pollution weather of type Ⅱ accounted for 22.2%of the total pollution days,which was caused by secondary nitrate(51.0%),supplemented by traffic source(5.3%),mainly from the northern and western source areas.Compared with type Ⅰ,the contribution of coal source and secondary sulfate was obviously higher.The pollution weather of type Ⅲ accounted for 11.1%of the total pollution days,mainly contributed by coal combustion and secondary sulfate,and mainly contributed by pollution emissions north of Dalian.
作者
杨萌
刘畅
王笑欢
彭晓
刘莲莲
曹姗姗
阎守政
殷雪华
孙泽宇
田崇国
YANG Meng;LIU Chang;WANG Xiaohuan;PENG Xiao;LIU Lianlian;CAO Shanshan;YAN Shouzheng;YIN Xuehua;SUN Zeyu;TIAN Chongguo(Dalian Ecological Environment Monitoring Center,Dalian 116023;Key Laboratory of Coastal Environmental Processes and Ecological Remediation,Shandong Key Laboratory of Coastal Environmental Processes,Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences,Yantai 264003;University of Chinese Academy of Sciences,Beijing 100049;Center for Ocean Meg-Science,Chinese Academy of Sciences,Qingdao 266071)
出处
《环境科学学报》
CAS
CSCD
北大核心
2024年第11期16-27,共12页
Acta Scientiae Circumstantiae
基金
国家自然科学基金项目(No.42177089,41977190)
中国科学院仪器设备功能开发技术创新项目(No.E32P030301)。
