贡嘎山海螺沟降雪中多环芳烃的短周期分布特征及来源分析

Short-term distribution and source apportionment of PAHs in the snow from Hailuogou, Gongga Mt.

2013年1月在贡嘎山海螺沟3个不同采样点共收集了多个雪样,利用GC-MS分析了雪样中16种优控多环芳烃的含量,探讨了多环芳烃的短周期分布特征与来源,估算了采样点与排放源的直线距离。结果显示,海螺沟各采样点雪样中多环芳烃的总含量在163.7 ng/L^281.4 ng/L之间,其中菲的含量最高。雪样中2~4环多环芳烃占多环芳烃总量的百分比为92.0%~93.7%,表明污染来自较远距离传输,但主要排放源离海螺沟的直线距离不超过357 km。将雪层与气象资料的降雪期对应,结果表明从2012年11月到2013年1月这个短周期内,海螺沟雪样受多环芳烃污染的程度没有太大变化。对海螺沟雪样中的多环芳烃进行了来源分析,结果表明海螺沟雪样中的多环芳烃主要来自煤燃烧,不排除少部分木材燃烧,这一源解析结果与海螺沟及其周边地区主要以煤炭作为燃料的能源特征相吻合。

Snow samples were collected from three sampling sites in the Hailuogou glacier of Gongga Mt. The concentration of 16 priority polycyclic aromatic hydrocarbons （PAHs） in these samples was determined by gas chromatography-mass spectrometry （GC-MS） to investigate the short-term distribution and source of PAHs in snow and estimate the distance between sampling sites and emission source of PAHs. The results showed that the total concentrations of 16 PAHs in the snow samples of Hailuogou glacier vary from 163.7 ng/L to 281.4 ng/L with the highest content of phenanthrene and the mass percentage of 2~4 ring PAHs ranges from 92.0% to 93.7%. Comparison of snow layers with the snowfall dates of meteorological data indicated that no obvious variation in the extent of PAH pollution was observed in the Hailuogou snows during the period from November 2012 to January 2013. The source apportionment suggested that the PAHs in the Hailuogou snows was mainly generated from coal combustion that occurred within a distance of less than 357 km from the Hailuogou glacier.