Polycyclic aromatic hydrocarbons in soils of Beijing and Tianjin region:Vertical distribution, correlation with TOCand transport mechanism
HE Fengpeng , ZHANG Zhihuan , WAN Yunyang , LU Song , WANG Liang , BU Qingwei
DOI:
Received January 17, 2008,Revised April 09, 2008, Accepted , Available online
Volume 21,2009,Pages 675-685
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The contents and distribution of 20 polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic hydrocarbons (HAHs) were
investigated in 16 soil profiles of Beijing and Tianjin region. Transport of high molecular weight PAHs (HMWPAHs) and the correlation
between total organic carbon (TOC) and their concentrations were also discussed. The results indicated that highly contaminated sites
were located at urban or wastewater irrigation areas and pollutants mainly accumulated in topsoil (< 40 cm), with a sharp content
decrease at the vertical boundary of 30–40 cm. Total PAHs/HAHs concentrations in soils from Tianjin were markedly greater than
those from Beijing. Even the contents at bottoms of soil profiles in Tianjin were higher than those in topsoils of Beijing soil profile.
HMWPAHs dominated the PAH profiles, exhibiting a uniform distribution of pyrogenic origin between topsoils and deep layers.
Furthermore, the percentages of HMWPAHs remained relative constant with the depth of soil profiles, which were consistent with
the distribution of particulate matter-associated PAHs in the local atmospheric environments. Therefore, HMWPAHs transport with
particulates might be the predominant source found in soil profiles.
