天津市道路环境大气颗粒物水溶性无机离子分析

大气颗粒物,尤其是其中的水溶性无机离子,对人体危害很大.天津市大气污染中机动车尾气污染相对较高,为探究不同道路类型下水溶性无机离子的污染特征,于2015年4~5月对天津市四类道路类型分别进行大气颗粒物PM_(2.5)和PM_(10)采样及水溶性离子组分分析,并运用皮尔森相关性分析、水溶性离子比值关系分析及主成分分析方法进行探讨.结果表明,天津市水溶性无机离子主要集中在细颗粒物中,不同离子在不同道路下所占质量分数差异很大,二次污染相对较重;二次离子是水溶性无机离子的重要组成部分,在细颗粒物中含量相对较高,在PM_(2.5)中的含量是PM_(10)中的1~2倍左右;K~+、Mg~(2+)、Na~+与Ca~(2+)之间有较高的同源性;各道路PM_(2.5)和PM_(10)第一贡献因子均是燃烧和二次污染的混合源,第二贡献因子主要为扬尘与交通混合源.

Water-soluble Inorganic Ions in the Road Ambient Atmospheric Particles of Tianjin

Atmospheric particles, especially water-soluble inorganic ions are hazardous to human body. Motor vehicle exhaust is the greatest contributor to atmosphere pollution in Tianjin. In order to explore the emission characteristics of different road types, PM_2.5 and PM₁₀ from four types of roads were sampled and analyzed by water-soluble ions component analysis and Pearson correlation analysis during the period of April to May, 2015 to discover the ratio of PM_2.5 to PM₁₀ and the major pollutants. The results showed that water-soluble inorganic ions mainly existed in fine particles varying with different road types, which mainly came from secondary pollution. The quantities of secondary ions in PM_2.5 were twice as high as that in PM₁₀, which were the key components of the water-soluble inorganic ions. This was probably due to the increase of automobiles and their emissions, as well as the transmission and spreading of pollutants in the surroundings. Furthermore, water-soluble inorganic ions might exist in the forms of NaNO₃, NH₄Cl, NH₄NO₃, (NH₄)₂SO₄, KCl, KNO₃, K₂SO₄, MgCl₂, CaCl₂, etc. K⁺, Mg²⁺, Na⁺and Ca²⁺ showed high homology and the contributors of PM_2.5 and PM₁₀ were mainly the mixture of combustion and secondary pollutants, then followed by the mixture of re-suspended dust and traffic source.