京津冀地区城市环境空气颗粒物及其元素特征分析

于2013年四个季度,选择京津冀3个主要城市和1个对照点,以及4个全国大气背景站,同步采集环境空气颗粒物PM10和PM2.5样品,采用微波消解ICP-MS法分析样品中的68种元素.结果表明,京津冀3个城市四个季度PM10和PM2.5均超过国家二级标准限值,且采暖季高于非采暖季.全年PM2.5/PM10比值大于0.5,细颗粒物污染占主导.元素在PM2.5中所占比例高于PM10.而背景点颗粒物浓度低于标准限值,远低于城市点,且四个季节变化不大.在检出的57种元素中,Na、Mg、Al、S、K、Ca、Fe、Zn在0.1~10μg/m3之间,P、Ti、Mn、Ni、Cu、Ba、Pb在10~100ng/m3之间,其他含量较低元素如Cd、Co、Ge、Ga、Zr、Sr、V等在0.01~10ng/m3之间.元素S、Na、K、Al、Fe、Mg、Ca等含量大于1%,P、Zn、Pb、Cu、Ba等其他元素含量介于0.1%~1%.富集因子分析结果提示,K、Ca、Cr、Fe、Cu、Zn、As、Cd和Pb等9种元素主要来源于人为污染,采暖季与非采暖季富集因子比值在1.1~3.5之间.因子分析提示,燃煤、工业污染源、燃油等是颗粒物污染的主要贡献因素.

Characterization of elements in air particulate matters in Beijing-Tianjin-Hebei megacities,China

Air particulate matter samples from three Beijing-Tianjin-Hebei megacities, a reference and four national background sites were collected. 68 elements in PM10 and PM2.5 were analyzed with microwave-assisted digestion and inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the daily mass concentrations of PM10 and PM2.5 in three Beijing-Tianjin-Hebei megacities were much higher than the relevant Chinese air quality standards. The concentrations in heating season were much higher than those in non- heating season. The ratios of PM2.5/PM10 were higher than 0.5, which indicated PM2.5 was the main component of PM pollution. The concentrations of PM10 and PM2.5 in national background sites changed slightly in seasons and were lower than the air quality standards and the city sites. The concentrations of Na, Mg, Al, S, K, Ca Fe and Zn were in the range of 0.1~10μg/m3; P, Ti, Mn, Ni, Cu, Ba and Pb 10~100ng/m3; Cd、Co、Ge、Ga、Zr、Sr and V 0.01~10ng/m3. The contents of S, Na, K, Al, Fe, Mg and Ca were all higher than 1%. The contents of the other elements including P, Zn, Pb, Cu and Ba were ranged in 0.1%~1%. The enrichment factors analysis revealed that K, Ca, Cr, Fe, Cu, Zn, As, Cd and Pb were enriched in PM2.5, which suggested the anthropogenic sources in this region. The enrichment factor ratio of heating season to non-heating season were 1.1~3.5. The factor analysis indicated that coal combustion, factory emissions and fuel combustion were primary sources of the air particulate matter pollution.