生态环境学报2018，Vol.27Issue(4)：714-721,8.DOI:10.16258/j.cnki.1674-5906.2018.04.017
温湿度对南京北郊PM2.5中二次无机离子生成演化的影响
Influences of Temperature and Humidity on Formation and Evolution of Secondary Aerosol Inorganic Ions of PM2.5at Northern Suburban Nanjing
摘要
Abstract
As the important components of PM2.5, it is of great significance to study the formation and evolution of secondary inorganic ions and their influencing factors in the process of atmospheric pollution for further understanding of the formation and dissipation mechanism of haze. In this study, the mass concentration of secondary aerosol inorganic ions of PM2.5and the influences of temperature and humidity on its formation and evolution were analyzed by using PM2.5and its water-soluble ion data from March 2016 to March 2017 in the northern suburb of Nanjing. The main conclusions were as follows: (1) The annual average concentration of total water-soluble ions (TWSI) in PM2.5was 41.35 μg·m-3, accounting for 69.94% of PM2.5. The main water-soluble ions were NO3-, SO42-, NH4+ (SNA) which contributed 91.78% of TWSI. (2) The average values of sulfur oxidation rate (SOR) was about 0.49 without obvious seasonal difference. SOR was higher with humidity increase especially when RH>60%. The proportion of SO42- in PM2.5increased with RH in winter and opposite in summer which might be related to the rising NO3- proportion. The intercept of ratio of n(NH4+)/n(SO42-) to n(NO3-)/n(SO42-) was greater in winter than that in summer, showing the sulfate was mainly exist as low acidity solid or liquid state (NH4)2SO4, NH4HSO4in the atmosphere of the northern suburbs of Nanjing. And (3) when the temperature was above 25 ℃, the gas-particle distribution index (FHNO3) of NO3- remarkably increased with temperature, indicating that the higher temperature was beneficial to the conversion of solid NH4NO3to gaseous HNO3. The effect of relative humidity was opposite to the temperature, especially when the temperature was higher than 25 ℃, the lower the relative humidity was more conducive to the transformation of the solid NH4NO3to the gaseous HNO3, which meant that the higher temperature was beneficial to the conversion of solid NH4NO3to gaseous HNO3while temperature did the opposite. The average FHNO3 under clean days was 0.07 which was 1.94 times in polluted days, which demonstrated formation of NH4NO3was more easily to generate in polluted days and aggravates air pollution.关键词
PM2.5/二次无机离子/生成演化/温湿度/MARGAKey words
PM2.5/secondary aerosol inorganic ions/formation and evolution/temperature and humidity/MARGA分类
资源环境引用本文复制引用
刘寿东,张莉,张园园,林昕,范美益,赵翔,曹芳,章炎麟..温湿度对南京北郊PM2.5中二次无机离子生成演化的影响[J].生态环境学报,2018,27(4):714-721,8.基金项目
国家自然科学基金重大研究计划培育项目(91644103) （91644103）
教育部长江学者和创新团队发展计划项目(IRT_15R36) （IRT_15R36）
江苏省青年基金项目(BK20150895) （BK20150895）
