摘要
天津市空气质量保障期间PM_(2.5)浓度为27μg/m^(3),达到历史同期最好水平;水溶性离子浓度为9.02μg/m^(3),比保障期前和保障期后分别降低64.70%和39.66%。各离子浓度由高到低为NO^(-)_(3)>NH^(+)_(4)>SO^(2-)_(4)>Cl^(-)>Na^(+)>K^(+)>NO^(-)_(2)>Ca_(2+)>Mg^(2+)>F^(-),NO^(-)_(3)、NH^(+)_(4)和SO^(2-)_(4)等二次离子是PM_(2.5)中最主要的离子成分。硫氧化率(SOR)和氮氧化率(NOR)分别为0.18和0.14,虽低于保障期前和保障期后,但仍存在明显的二次转化过程。NOR日变化趋势表明夜间及上午时段NO_(2)向NO^(-)_(3)的二次转化较为剧烈。
The average concentration of PM_(2.5)was 27μg/m^(3)during the military parade period,which was the best level since PM_(2.5)was monitored form 2013.The concentration of water-soluble ions in PM_(2.5)was 9.02μg/m^(3),64.70%and 39.66%lower than the periods before(11~22 August)and after(4~15 September).The concentration of ions followed from high to low by NO^(-)_(3)>NH^(+)_(4)>SO^(2-)_(4)>Cl^(-)>Na^(+)>K^(+)>NO^(-)_(2)>Ca^(2+)>Mg^(2+)>F^(-),and those NO^(-)_(3)、NH^(+)_(4),SO^(2-)_(4)were the main ionic components in PM_(2.5).The sulfur oxidation ratio(SOR)and nitrogen oxidation ration(NOR)was 0.18 and 0.14 showing the obvious secondary transformation processes,but the levels were lower than both before and after.Higher NOR were observed indicating more intense transformation reaction of NO_(2)to NO^(-)_(3)-at night and in the morning.
作者
李鹏
高璟赟
肖致美
毕温凯
李源
Li Peng;Gao Jingyun;Xiao Zhimei;Bi Wenkai;Li Yuan(Tianjin Eco-Environmental Monitoring Center, Tianjin 300191, China)
出处
《环境科学与管理》
CAS
2021年第3期95-99,共5页
Environmental Science and Management
基金
国家科技支撑计划项目(No.2014BAC23B01)。
