某油泥堆放场地中多环芳烃的污染及其垂向分布特征

通过采集某油田油泥堆放场地及其周边24个表层土壤样品和2个剖面土壤样品，采用超声波萃取-气相色谱/氢火焰离子化检测分析方法，对美国环境保护局(USEPA)优控的16种多环芳烃(PAHs)进行定量分析.结果表明:该研究区域的PAHs污染已较为严重，污染场地内16种PAHs的检出率为100%，w(PAHs)平均值为7 770.7 ng/g；周边土壤的16种多环芳烃的检出率为58.3%～100%，二苯并［a,h］蒽及茚并［1,2,3-cd］芘的检出率相对较低，w(PAHs)平均值为2 038.8 ng/g.研究区域内主要污染物为萘、苊、二氢苊、芴、菲、蒽、荧蒽、、芘、苯并［a］蒽和苯并［a］芘.从母体PAHs与污染物来源的关系和单组分比值可以看出，污染场地内及周边土壤的污染源是石油源和燃烧源的混合源.w(PAHs)在土壤剖面中的峰值出现在40～60及20～40 cm处，不同组分的PAHs在土壤剖面中的迁移能力表现为2～3环PAHs＞4环PAHs＞5～6环PAHs. 

Contamination and Vertical Distribution Characteristics of Polycyclic Aromatic Hydrocarbons at an Oil Sludge Storage Site

24 surface samples and 2 profile samples at a typical oil sludge storage site and in its peripheral soil were collected and analyzed. The UE-GC/FID method was used to quantitatively analyze the 16 kinds of PAHs which were controlled priority pollutants by the USEPA. The results showed that the study area was polluted severely by PAHs. The detection rate of the 16 kinds of PAHs at the contaminatedsites was 100%, in their peripheral soil it ranged from 58.3% to 100%, while the detection rate of dibenzo ［a,h］ anthracene and indeno ［1,2,3-cd］ pyrene was relatively low. The average quantity of PAHs reached 7 770.7 and 2 038.8 ng/g respectively. The main pollutants were naphthalene, acenaphthene, acenaphthylene, fluorene, phenanthrene, anthracene, fluoranthene, chrysene, pyrene, benzo［a］anthracene and benzo［a］pyrene. The pollution sources were mixed sources of combustion and oil sources according to mono-component ratio and relationship between precursor PAHs and the contaminants. The peak values of PAHs in the profiles appeared in the range of 40～60 and 20～40 cm. The ability of different PAHs components to transport downward changed in the profile, which was characterized as 2～3 ring PAHs>4 ring PAHs>5～6 ring PAHs.