材料期刊网

快速的经济发展和城市化进程造成我国城市大气污染日益显著,并受到更为广泛的关注.为了解济南市大气细粒子及其化学成分的污染特征,于2013.10.15-2013.11.16和2013.12.24-2014.1.27(总观测天数为62天)利用中流量颗粒物采样器采集了济南市大气PM2.5样品,分析了其中的化学成分,包括水溶性离子、无机金属元素、元素碳(EC)和有机碳(OC),并结合颗粒物质量重构法和主成分分析法探讨了济南市大气细粒子的来源.结果表明,监测期内济南市PM2.5质量浓度严重超标,日均值均高于我国国家环境空气质量标准(GB3095-2012)中的一级标准,最高日均值达到了335 μg·m-3.水溶性离子、有机碳、元素碳和金属元素分别占总PM25浓度的45.3％、34.7％、2.3％、5.6％(秋季),42.8％、32.9％、3.6％、12.5％(冬季).二次水溶性离子NO3-、SO42-和NH4+为主要的水溶性离子,分别占总离子浓度的34.1％、35.6％、9.2％(秋季)和35.2％、30.4％、15.9％(冬季).OC和EC的平均质量浓度分别为33.8.μg· m-3和4.3 μg·m-3,OC/EC比值表明秋季汽车尾气与生物质燃烧对有机气溶胶的贡献较大,而冬季燃煤排放对有机气溶胶的贡献较大.化学质量重构结果表明,秋季济南市细粒子中二次无机盐、海盐、重金属、矿物尘、建筑尘、有机物和元素碳的质量百分比分别为38.6％、1.2％、0.2％、5.4％、1.4％、34.7％和2.3％,冬季分别为34.8％、1.5％、3.5％、7.5％、3.2％ 、33.0％和3.6％.主成分分析结果表明,汽车尾气及二次转化、燃煤以及冶炼工业排放是济南市大气细粒子的主要来源.

With the rapid development of the economy and urbanization,the urban air pollution in China has become dominant,and has attracted more attentions than before.Fine particles (PM2.5),collected from 15 October 2013 to 27 January 2014 in Ji'nan,Shandong province were analyzed for water-soluble ions (WSI),metal elements,elemental carbon (EC) and organic carbon (OC) to investigate the characteristic and sources of PM2.5.Results indicated that pollution of atmospheric fine particles in Ji'nan city was very serious,and the daily average of PM2.5,exceeded level I of the National Standard (GB3095-2012),up to 335 μg · m-3 Percentages of measured chemical species,WSI,OC,EC and metal elements,to PM2.5 were 45.3％,34.7％,2.3％ and 5.6％ in the autumn,42.8％,32.9％,3.6％ and 12.5％ in the winter,respectively.Secondary water-soluble ions including NO3-、SO42-and NH4+ were the main water soluble ions,accounting for 34.1％,35.6％ and 9.2％ in the autumn and 35.2％,30.4％ and 15.9％ in the winter of all measured ions.The average concentrations of OC and EC were 33.8 μg· m-3 and 4.3 pg·m-3.It could be concluded from the ratio of OC/EC that vehicle exhaust and biomass burning in autumn and coal emissions in the winter were the main contributors to organic aerosols.The results of mass closure indicated that percentages of secondary inorganic salt (SIA),sea salt (SS),heavy metal (HM),mineral dust (MIN),construction dust (CD),organic matter (OM),and EC were 38.6％,1.2％,0.2％,5.4％,1.4％,34.7％ and 2.3％ for autumn,and 34.8％,1.5％,3.5％,7.5％,3.2％,33.0％ and 3.6％ for winter,respectively.The results of PCA indicated that vehicle exhaust,second transformation,coal combustion and industrial emissions were the main sources of PM2.5 in Ji'nan.