鞍山市大气PM_(10)中多环芳烃(PAHs)的污染特征及其来源

Pollution Characteristics and Source Analysis of PAHs in PM_(10) in Anshan City

2005年3月和8月在辽宁省鞍山市8个采样点采集PM10样品,用液相色谱-质谱法分析了PM10上负载的11种多环芳烃(PAHs),并探讨了其分布特征和来源.结果表明:鞍山市PM10中ρ(ΣPAHs)时空变化特征显著,冬季高于夏季,且工业区PAHs污染最严重;在PAHs中4环以上的组分占主导,冬季ρ(4环PAHs)较高,而在夏季ρ(5～6环PAHs)较高.运用比值法和主成分分析法对PAHs来源进行分析,发现冬季的主要污染源为燃煤排放、机动车尾气排放和炼钢工业排放;夏季主要污染源为燃煤排放、机动车尾气排放、生物质燃烧排放和炼钢工业排放等,来源较冬季复杂.机动车尾气排放对PAHs的贡献在2个季节都较为明显,冬季燃煤排放的贡献比重明显增加.

Atmospheric PM10 samples were collected at eight sampling sites in Anshan City in March and August 2005.The mass concentrations of 11 polycyclic aromatic hydrocarbons（PAHs） loaded in the PM10 samples were measured by LC /MS method,and distribution characteristics and sources of PAHs were discussed.The results showed that the total mass concentrations of PM10-bound PAHs varied temporally and spatially to a remarkable extent,with higher concentrations in winter than in summer,and the highest concentrations in the industrial area of Anshan City.PAHs species with four or more rings comprised the most PAHs.Mass concentrations of four-ring PAHs were higher in winter,while mass concentrations of PAHs with five and six-rings were higher in summer.The sources of PAHs were analyzed using diagnostic ratio method and principal component analysis method.It was found that coal combustion,vehicle exhaust and steel industry emissions were three major sources of PM10-bound PAHs in winter.However,in addition to those source contributors,other sources such as biomass combustion might contribute to the atmospheric PM10-bound PAHs in summer.In summary,vehicle exhaust was recognized to be the most significant PAHs contributor in both summer and winter,while the contribution of coal combustion clearly increased in winter.