摘要
使用MARGA离子在线分析仪ADI2080对2017年12月27日～2018年1月5日南京市PM_(2.5)化学组分进行连续采样分析,结合气象要素和大气环境监测数据,探讨了霾污染过程中水溶性离子的时间分布特征及其来源特征.结果表明:霾日中南京水溶性离子浓度为121.41μg/m^3,是洁净日的3.2倍.霾污染过程中水溶性离子平均浓度大小顺序为NO_3^-> SO_4^(2-)> NH_4^+> Cl^-> K^+> Ca^(2+)> Mg^(2+),SNA离子占总水溶性离子浓度的91.97%.霾日中水溶性离子日变化均为三峰型,洁净日中Cl^-、SO_4^(2-)和NH_4^+的日变化为单峰型,Ca^(2+)为双峰型,K^+、Mg^(2+)为三峰型.随着空气污染状况的加重,总水溶性离子在PM_(2.5)中的占比不断减少,空气质量为优时占比95.93%,严重污染时为63.25%.霾日中随着污染加重,NH_4^+占总离子的比例稳定在23%左右,SO_4^(2-)占比缓慢减小,NO_3^-占比不断增大.NOR、SOR的日变化在霾日呈双峰型分布,洁净日则较为平稳.观测期间的水溶性离子主要来源有二次转化、煤烟尘、扬尘以及生物质燃烧.
The composition of Pm2.5 was monitored online continuously by using MARGA 1 S Analyzer ADI 2080 in Nanjing from December 27, 2017 to January 5, 2018. Combined with meteorological elements and atmospheric environmental monitoring data, the time distribution and source characteristics of water-soluble ions in haze pollution process was investigated. The mass concentration of water-soluble ions in Nanjing during the haze pollution was 121.41μg/m^3, 3.2 times of the level in clean days. The order of the average mass concentration of water-soluble ions in the haze pollution process was NO3^-> SO4^2-> NH4^+> Cl^-> K^+> Ca^2+> Mg^2+.SO4^2-, NO3^- and NH4^+ accounted for 91.97% of the total water-soluble ions concentration. The diurnal variations of water-soluble ions in haze days were all trimodal, while in clean days, Cl^-, SO4^2-and NH4^- were unimodal, Ca^2+ was bimodal, K^+ and Mg^2+ were trimodal. With the aggravation of the air pollution, the proportion of total water-soluble ions in Pm2.5 was decreasing. When the air quality was excellent, the proportion was 95.93%, while it was 63.25% when serious pollution occurred. With the increase of pollution in haze days, the proportion of NH4^+ to total water-soluble ions was stable at around 23%, the proportion of SO4^2-decreased slowly, and the proportion of NO3^-increased continuously. The diurnal variations of NOR and SOR were bimodal in haze days, while in clear days, they were relatively stable. During the observation period, water-soluble ions were derived mainly from secondary conversion, coal ash, dust, and biomass combustion.
作者
刘安康
王红磊
陈魁
卢文
施双双
刘贞
LIU An-kang;WANG Hong-lei;CHEN Kui;LU Wen;SHI Shuang-shuang;LIU Zhen(Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration,Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science &Technology,Nanjing 210044,China;Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention,Shanghai 200433,China;Qinhuangdao Meteorological Bureau,Qinhuangdao 066000,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2019年第5期1793-1803,共11页
China Environmental Science
基金
国家自然科学基金资助项目(41805096
41575132)
江苏省自然科学基金资助项目(BK20180801)
江苏省高等学校自然科学研究项目(18KJB170011)
上海市大气颗粒物污染防治重点实验室开放课题(FDLAP18006)
河北省气象局青年基金资助项目(17ky25)
