摘要
对2016年3月南京北郊PM_(2.5)进行采样分析,通过样品中的水溶性离子(Na^+、NH_4^+、K^+、Ca^(2+)、Mg^(2+)、Cl^-、NO_3^-、SO_4^(2-))和碳质组分(OC、EC),探讨霾污染的特征、来源及硫酸盐形成机制.结果表明,采样期间南京北郊PM_(2.5)平均浓度(103.22±48.5)μg/m^3.污染天二次硫酸盐的形成与NO_2对SO_2的氧化相关性较强,而O_3的氧化作用影响较小;清洁天则相反.污染天,具有酸度缓冲作用的矿物粉尘使得气溶胶颗粒物总体呈弱碱性,而碱性环境下又更利于二次硫酸盐的形成.南京北郊早春二次污染严重,SOC主要由大气中碳氢化合物与O_3发生光氧化反应生成.污染天主要排放源为机动车尾气排放,其次是生物质和煤炭燃烧;清洁天主要排放源为煤炭燃烧和扬尘,机动车尾气影响较小.
To investigate the characteristics and sources of haze pollution and the formation mechanism of sulfate the northern suburb of Nanjing,PM2.5 samples were collected in March 2016,and the concentrations of water-soluble ions(Na^+,NH4^+,K^+,Ca^2+,Mg^2+,Cl^-,NO3^-and SO4^2-)and carbonaceous components(OE and EC)were measured.The average concentration of PM2.5 during the sampling period was(103.22±48.5)μg/m3.In contrast to clean days,the formation of secondary sulphate in the polluted days was much stronger related to the oxidation of SO2 by NO2 than the oxidation with O3.The mineral dust could serve as buffered agent and kept the aerosol in weakly alkaline state during polluted days,which was preferred for the secondary sulfate formation.In this work,the secondary organic carbon(SOC)in PM2.5 was mainly formed from the photooxidation of hydrocarbons with O3.The main sources of PM2.5 components in polluted days were motor vehicle emissions,followed by biomass and coal combustion.In clean days,the bulk components were mainly contributed by coal combustion and dust emission with little influences from motor vehicle exhaust.
作者
赵云卿
陈善莉
朱彬
郭照冰
ZHAO Yun-qing;CHEN Shan-li;ZHU Bin;GUO Zhao-bing(School of Environmental Science and Engineering,Nanjing University of Information Science&Technology,Nanjing 210044,China;Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control,Nanjing 210044,China;School of Atmospheric Physics,Nanjing University of Information Science&Technology,Nanjing 210044,China)
出处
《中国环境科学》
EI
CAS
CSSCI
CSCD
北大核心
2018年第7期2438-2444,共7页
China Environmental Science
基金
国家自然科学基金资助项目(41373023
41625006)
江苏省"333人才工程"项目
江苏省"青蓝工程"项目
江苏省大学生创新训练计划项目(201710300019)
江苏环保科研课题项目(2017010)