【摘要】 分析了密云水库沉积柱中16种美国EPA优先控制的多环芳烃(∑PAH16)的垂直分布状况,并对其来源和生态风险进行了分析和评估,目的是了解密云水库近年来PAHs污染的变化趋势.从底层16 cm至表层,沉积物中∑PAH16的含量在618.5~1 087.9 ng/g之间,且基本上一直呈上升的趋势.沉积物中多环芳烃的组成以3环的菲和芴为主,它们的含量分别为236.1~417.9 ng/g和91~130.8 ng/g,二者共占沉积物中多环芳烃总量(∑PAH16)的47.2%~58.1%.然而,高环数(5~6环)多环芳烃的比例近年来有逐渐增加的趋势.多环芳烃的组成特征显示密云水库的沉积物中多环芳烃主要来源于煤和木材的低温燃烧.然而,Flu/Flu+Pyr和INP/INP+BghiP比值的垂直变化说明,近年来机动车辆尾气排放的多环芳烃有增加的迹象.风险评价的结果显示:除了芴和菲之外,密云水库沉积物中的多环芳烃对生态环境的影响目前还处于较低风险水平.更多还原

【Abstract】 The temporal distribution of polycyclic aromatic hydrocarbons（PAHs） was measured in sediment core from Miyun reservoir,and the possible sources and the potential risk assessment also have been identified.The aim of the present work is to understand the temporal trend of PAHs in Miyun reservoir recently.The concentrations of ∑PAH₁6 in sediment ranged from 618.5 ng/g to 1087.9 ng/g,and roughly,increased continuously from the bottom（16cm under the surface） to the surface sediment.The PAHs in sediment core were mainly composed of phenanthrene and fluorene.The concentrations of phenanthrene and fluorene in sediment core were 236.1-417.9 ng/g and 91-130.8 ng/g,respectively.Both of them accounted for 47.2%-58.1% of the ∑PAH₁6 in sediments.Nevertheless,high-rings aromatic hydrocarbons（5-6 rings） were increased steadily in recent years.PAHs compositional profile indicated that the main source of PAHs was originated from the combustion of coal and biomass.However,the vertical profiles of Flu/Flu+Pyr and INP/INP+BghiP ratios suggested that the vehicles emission was increased very recently.Risk assessment suggested that PAHs in sediment from Miyun reservoir was no significant biological impairment,and low toxicological risk of PAHs was found up to now.更多还原