天津市2017年重污染过程二次无机化学污染特征分析  

Secondary Inorganic Pollution Characteristics During Heavy Pollution Episodes of 2017 in Tianjin

作　　者：徐虹 肖致美 陈魁 李立伟 杨宁 高璟赟 李源 孔君 毕温凯 邓小文 XU Hong;XIAO Zhi-mei;CHEN Kui;LI Li-wei;YANG Ning;GAO Jing-yun;LI Yuan;KONG Jun;BI Wenkai;DENG Xiao-wen(Tianjin Eco-Environmental Monitoring Center,Tianjin 300191,China)

机构地区：[1]天津市生态环境监测中心,天津300191

出　　处：《环境科学》2019年第6期2519-2525,共7页Environmental Science

基　　金：天津市科技计划项目(16YFZCSF00260);国家重点研发计划项目(2016YFC0208501;2016YFC0208502;2016YFC0208506)

摘　　要：基于2017年天津市超级观测站数据,筛选出7次典型重污染过程,从污染物浓度、二次转化方面分析重污染过程二次无机化学污染特征.结果表明,重污染期间NO_3^-和SO_4^(2-)浓度较清洁天气增长幅度最高,显著高于PM_(2.5)的增长程度,说明二次无机转化是导致重污染期间PM_(2.5)污染加重的重要原因;下半年PM_(2.5)和SO_2污染程度较上半年减轻,与秋冬季采取燃煤治理等活动有关;重污染期间NO_2/SO_2比值为1.5～19.6,其中下半年NO_2/SO_2比值显著高于上半年,说明在各项污染源管控下移动源的影响比例相对增加;大部分重污染期间NO_3^-浓度大于SO_4^(2-)浓度,SOR值高于NOR值,说明重污染期间硫酸盐和硝酸盐转化均较重要;在SO_2浓度显著降低的情况下,重污染期间SO_4^(2-)浓度并未明显降低,说明除二次无机转化外,硫酸盐生成还受其他因素影响.Based on monitoring data collected at the supersite of Tianjin in 2017,seven typical heavy pollution episodes were investigated. The concentrations of air pollutants and secondary inorganic transformation products were analyzed to study the secondary inorganic pollution characteristics during the heavy pollution episodes. Compared to clean weather,concentrations of NO3^- and SO4^2- during the heavy pollution episodes increased at rapid growth rates. These rates were obviously higher than the rate for PM2.5 increases,which indicates that the secondary inorganic reactions had an important influence on PM2.5 pollution during the episodes. The concentrations of PM2.5 and SO2 during the episodes in the latter half of the year were lower than those in the first half of the year probably because a substantial amount of coal use had been controlled. During the heavy pollution episodes,the NO2/SO2 values were 1. 5 to 19. 6,with higher values in the latter half of the year than the first half of the year suggestive of a greater influence from mobile sources. During most episodes,NO3^- concentrations were higher than SO4^2- concentrations,and SOR values were higher than NOR values,which shows that the secondary transformation of nitrate and sulfate both played important roles during the heavy pollution episodes. When SO2 concentrations decreased significantly,SO4^2- concentrations did not decrease obviously,thus indicating that besides the secondary inorganic reactions,other factors also had a large impact on the generation of sulfate.

关 键 词：天津 重污染 2017年 二次转化 污染特征 

分 类 号：X513[环境科学与工程—环境工程]