扎龙湿地沉积物垂向剖面中多环芳烃分布特征

对扎龙湿地核心区沉积物分层取样，以正己烷/二氯甲烷为提取剂，用超声波方法提取沉积物中16种优控PAHs，采用GC/MS法定量分析w(PAHs). 结果表明，扎龙湿地剖面沉积物中2环和3环PAHs占PAHs总量的86%以上，4环以上的PAHs所占比例较小. 在各层沉积物中含量较高的萘、菲、芴及PAHs总量随深度的增加而减小，沉积物表层0～10 cm内的w(PAHs)最高，达396.61 ng/g. 表层沉积物中含量较高的PAHs为萘>菲>芴>荧蒽>芘>二氢苊>苊烯>. w(PAHs)与沉积物中w(TOC)呈正相关关系，相关系数为0.9347. 从扎龙湿地的低环PAHs污染特征以及同周边地区大气颗粒物中的PAHs对照分析表明，扎龙湿地沉积物中的PAHs主要来源于石油类污染. 

Distributional Characteristics of Polycyclic Aromatic Hydrocarbons in Vertical Section of Sediments from Zhalong Wetland

The 16 prior polycyclic aromatic hydrocarbons (PAHs) were extracted with the use of a ultrasonic batch with the mixture of hexane and dichloromethane as extractants from the samples from the vertical section of sediments from Zhalong wetland. The PAHs were quantitatively analyzed with GC/MS. The results show that the sum of the PAHs with 2 or 3 aromatic rings is more than 86% of the total PAHs, while the sum of the PAHs with 4 or more aromatic rings is only small fraction of the total PAHs. Among all the layer of sediments, the contents of naphthalene, phenanthrene, fluorine, and the total amount of PAHs decrease as the sediment is deeper from surface. The total amount of the PAHs was the highest in the surface sediment (0～10 cm) layer, being 396.61 ng/g. The order of the PAHs concentration in the surface sediment layer is: naphthalene > phenanthrene > fluorine > dibenzo［a,h］anthracene > pyrene > acenaphthene > acenaphthylene> chrysene. The content of the PAHs is directly proportional to the content of TOC with a correlation coefficient of 0.934 7. The contrast analysis of the pollution charactersof low ring PAHs at Zhalong wetland to those of atmospheric particles at its surrounding areas indicates the PAHs in the sediments from Zhalong wetland mainly from oil pollution.