加拿大阿萨巴斯卡地区Mildred泥炭柱多环芳烃分布特征及来源解析

Distribution Characteristics and Source Apportionment of Polycyclic Aromatic Hydrocarbons in Mildred Peat Core from the Athabasca Region, Canada

利用气相色谱-质谱联用仪(GC-MS),对加拿大阿萨巴斯卡地区Mildred泥炭柱的35个泥炭样品的多环芳烃(polycyclic aromatic hydrocarbons,PAHs)浓度进行了测定,分析了其含量分布特征;采用特征比值和主成分分析-多元线性回归方法,解析PAHs的源。研究结果表明,泥炭样品中的PAHs以菲系列、二苯并噻吩系列、4环PAHs(荧蒽、芘、?)为主,萘系列及5环及以上PAHs含量偏低而难以被检测出来;泥炭柱中的PAHs含量为0.7～12.0μg/g,且随着深度的加深逐渐减少,其最大值出现在近地表处;泥炭柱中的PAHs主要是周边油砂工业活动排放造成,属于异地石油源,少部分PAHs源于化石燃料和木材燃烧,大气中的PAHs迁移和沉降是泥炭柱中的PAHs的主要输入途径;Mildred泥炭地中石油源的PAHs贡献率最大,所占比例为76.3%,化石燃料燃烧和树木燃烧排放的PAHs所占比例分别为12.9%和10.8%。

Polycyclic aromatic hydrocarbons (PAHs) in 35 peat samples collected from the Mildred peat core in the Athabasca Region, Canada, were quantitatively analyzed by gas chromatograph mass spectroscopy (GCMS). The distribution pattern of PAHs was discussed, and the PAHs source apportionment was conducted by characteristic ratio analysis and principal component analysis- multivariable linear regression. The results showed that many kinds of PAHs in peat samples were found, mainly including phenanthrene series, dibenzothiophene series, 4- rings PAHs (fluoranthene, pyrene, chrysene), whereas naphthalene series and 5- rings and above PAHs could not be detected because of low content. The concentrations of PAHs ranged between 0.7 pig/g and 12.0 pg/g, with gradually decreased trend with the depth. The maximum PAHs concentration occurred on or near the surface. PAHs deposition in the Mildred peat core was mainly caused by emissions from the surrounding oil sand industries, while a small portion of PAHs was derived from fossil fuel and wood combustions. Atmospheric migration and subsidence was the important pathway of the input of PAHs to the peat land. The primary source of PAHs was the petroleum source and its contribution rate was 76.3%. PAHs derived from fossil fuel combustion and wood combustion contributed up to 12.9% and 10.8%, respectively.