南京北郊冬季细颗粒物中水溶性离子的变化趋势  

Variation trend of water-soluble ions in fine particulate matter in the northern suburbs of Nanjing in winter

作　　者：浮天 蒋伯琪 张佳颖 陈爱军[1] 胡建林 于兴娜[1] FU Tian;JIANG Boqi;ZHANG Jiaying;CHEN Aijun;HU Jianlin;YU Xingna(Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration,School of Atmospheric Physics,Nanjing University of Information Science and Technology,Nanjing 210044;Jiangsu Key Laboratory of High Technology for Atmospheric Environment Monitoring and Pollution Control,School of Environmental Science and Engineering,Nanjing University of Information Science and Technology,Nanjing 210044)

机构地区：[1]南京信息工程大学大气物理学院,中国气象局气溶胶-云-降水重点开放实验室,南京210044 [2]南京信息工程大学环境科学与工程学院,江苏省大气环境监测与污染控制高技术研究重点实验室,南京210044

出　　处：《环境科学学报》2024年第3期310-316,共7页Acta Scientiae Circumstantiae

基　　金：国家重点研发计划(No.2019YFC0214604);国家自然科学基金(No.41775154);安徽省重点研究与开发计划(No.2022h11020008);江苏省“六大人才高峰”项目(No.JNHB-057)。

摘　　要：为了探究南京北郊冬季PM_(2.5)组分的长期变化特征、污染来源差异,于2014年、2015年、2019年和2021年冬季分别开展细颗粒物采样,使用离子色谱仪对PM_(2.5)中9种水溶性离子进行分析测定,并运用主成分分析法对离子进行源解析.结果表明:二次离子SO_(4)^(2-)、NO_(3)^(-)和NH4+(SNA)占离子总浓度的75%~87%,其中,SO_(4)^(2-)与NH_(4)^(+)的离子浓度在2015年冬季达到峰值后出现逐年下降趋势,但NO_(3)^(-)的浓度与占比在2014—2019年均表现出上升趋势.4年中SO_(2)的二次转化程度均高于NO2,硫氧化率(SOR)于2019年达到最大值,而氮氧化率(NOR)则逐年下降.2019年起移动源对颗粒物的贡献程度大幅上升,固定源的贡献降低,NO_(3)^(-)/SO_(4)^(2-)比值显著增大.冬季NH4+、SO_(4)^(2-)、NO_(3)^(-)呈显著相关,推测主要结合为(NH_(4))_(2)SO_(4)、NH_(4)HSO_(4)和NH_(4)NO_(3)存在.主成分分析结果表明,移动源和燃烧源是南京北郊冬季PM_(2.5)的主要贡献者,然而2019年冬季与SO_(4)^(2-)相关的燃料燃烧源贡献显著降低,2021年扬尘源和工业源对PM_(2.5)的贡献相较于2019年有明显下降.To explore the long-term variation characteristics and the source differences of PM_(2.5)in winter in the northern suburbs of Nanjing,fine particulate matter samples were collected in winters of 2014,2015,2019,and 2021,respectively.The concentrations of 9 water-soluble ions in PM_(2.5)were determined using the ion chromatography,and source apportionment was employed by principal component analysis method.The results showed that the concentrations of secondary SO_(4)^(2-),NO_(3)^(-),and NH_(4)^(+)(SNA)accounted for 75%~87%of the total ion concentrations.Among them,the ion concentrations of SO_(4)^(2-)and NH_(4)^(+)peaked in winter of 2015 and showed a decreasing trend from 2019 to 2021,while the concentrations and fractions of NO_(3)^(-)increased between 2014 and 2019.The secondary transformation of SO_(2)was higher than that of NO_(2) in all four years,with SOR reaching the maximum value in 2019,but decreasing in NOR year by year.From 2019,the contribution of mobile sources to particulate matter has increased significantly,while the contribution of stationary sources decreased,with the remarkable rise of NO_(3)^(-)/SO_(4)^(2-)-ratio.The relationships between NH_(4)^(+),SO_(4)^(2-),and NO_(3)^(-)were significantly correlated in winter,suggesting that the existence as(NH_(4))_(2)SO_(4),NH_(4)HSO_(4),and NH_(4)NO_(3).The mobile and combustion sources were the main contributors to PM_(2.5)in winter in the northern suburbs of Nanjing based on the method of principal component analysis.However,the contributions of fuel combustion sources related to SO_(4)^(2-)distinctly declined in winter of 2019,and the contributions of dust and industrial sources to PM_(2.5)decreased obviously compared to 2019.

关 键 词：PM_(2.5) 水溶性离子 变化趋势 来源解析 南京市 

分 类 号：X513[环境科学与工程—环境工程]