摘要
为探究宝鸡市秋季大气PM_(2.5)中水溶性离子的污染特征及来源,于2019年10月15日至11月14日分别对宝鸡市监测站、文理学院和陈仓区环保局的3个站点进行PM_(2.5)样品采集,通过离子色谱仪得到水溶性离子质量浓度,分析了3个站点水溶性离子在清洁时段和污染时段的变化特征及来源.结果表明,三站点PM_(2.5)的质量浓度陈仓区环保局>文理学院>宝鸡市监测站.清洁时段和污染时段PM_(2.5)平均质量浓度分别为40.0μg·m^(-3)和100.1μg·m^(-3),水溶性离子平均质量浓度分别为(13.7±7.7)μg·m^(-3)和(57.8±15.0)μg·m^(-3).污染时段NO_(3)^(-)/SO_(4)^(2-)值是清洁时段的1.6—1.8倍.污染越重,SNA(NO_(3)^(-)、SO_(4)^(2-)和NH_(4)+)质量浓度越大,占总水溶性离子和PM_(2.5)的比例也越大.清洁时段,SNA主要以NH_(4)HSO_(4)形式存在,污染时段主要以(NH_(4))2SO_(4)和NH_(4)NO_(3)的形式存.秋季大气PM_(2.5)整体偏中性,污染加重,碱性加强.PCA-MLR模型分析得知,秋季水溶性离子污染主要来源有二次生成源、燃煤燃烧源和扬尘源,清洁时段主要污染来源为二次生成源,贡献率为61.3%,污染时段主要来源于二次生成及燃烧混合源,贡献率达到99.2%.轨迹聚类结果得出污染源主要为本地及周边传输.
In order to explore the pollution characteristics and sources of water-soluble ions in autumn atmospheric PM_(2.5) in Baoji City,and to study the difference between cleaning period and pollution period,PM_(2.5) samples were collected from Baoji Monitoring Station,College of Arts and Sciences and Chencang Environmental Protection Bureau from October 15,2019 to November 14,2019 and analyzed for water-soluble ions by ion chromatography.The variation characteristics and emission sources of water-soluble ions at the three sites during cleaning period and pollution period were then investigated.The results showed that the average concentration of PM_(2.5) in the three stations was 40.0μg·m^(-3) and 100.1μg·m^(-3) in the pollution period and clean period,respectively,at the>College of Arts and Sciences,Chencang District Environmental Protection Bureau,Baoji City.The average mass concentrations of water-soluble ions were(13.7±7.7)μg·m^(-3) and(57.8±15.0)μg·m^(-3) at the cleaning period and the pollution period,respectively.NO_(3)-concentration was the highest at different periods,followed by SO_(4)^(2-)and NH_(4)^(+).The NO_(3)-/SO_(4)^(2-)values at the three stations during the polluted period increased by 1.6-1.8 times compared with the clean period.The heavier the pollution,the greater the mass concentration of SNA,and the greater the proportion of SNA in TWSIS and PM_(2.5).During the cleaning period,SNA mainly exists in the form of NH_(4)HSO_(4),while during the pollution period,SNA mainly exists in the form of(NH_(4))2SO_(4) and NH_(4)NO_(3).During the observation period,the overall atmospheric PM_(2.5) was neutral,pollution increased and acidity decreased slightly.PCA-MLR model analysis showed that the main sources of water-soluble ion pollution in autumn were secondary conversion,combustion and dust sources.The main pollution source in clean period was secondary generation source,with a contribution rate of 61.3%.The main pollution source in pollution period was secondary generation and combustion mixed sources,with an average contribution rate of 99.2%.According to the result of track clustering,the pollution is mainly caused by local and surrounding transportation.
作者
周变红
冯瞧
王锦
李春燕
许东东
李建军
ZHOU Bianhong;FENG Qiao;WANG Jin;LI Chunyan;XU Dongdong;LI Jianjun(Shaanxi Key Laboratory of Disaster Monitoring and Mechanism Simulation,College of Geography&Environment,Baoji University of Arts&Sciences,Baoji,721013,China;Key Laboratory of Aerosol Chemistry and Physics,State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi'an,710061,China;Earth Environment Innovation Research Institute of Xi’an,Xi’an,710061,China)
出处
《环境化学》
CAS
CSCD
北大核心
2022年第5期1673-1683,共11页
Environmental Chemistry
基金
国家大气重污染成因与治理攻关项目(DQGG-05-36)
国家自然科学基金(41977332)
陕西省自然科学基础研究项目(2019JQ4041)
中国科学院气溶胶化学物理重点实验室项目(KLACP2004)
宝鸡文理学院重点项目(ZK2018049)资助。
关键词
宝鸡市
水溶性离子
轨迹聚类
来源解析
Baoji
water-soluble ion
trajectory clustering
source apportionment
