Black carbon (BC) in urban and surrounding rural soils of Beijing, China: Spatial distribution and relationship with polycyclic aromatic hydrocarbons (PAHs)

Autor: Liu, Shaoda1, Xia, Xinghui xiaxh@bnu.edu.cn, Zhai, Yawei1, Wang, Ran1, Liu, Ting1, Zhang, Shangwei1
Předmět:
Zdroj: Chemosphere. Jan2011, Vol. 82 Issue 2, p223-228. 6p.
Abstrakt: Abstract: The concentrations of black carbon (BC), total organic carbon (TOC) and polycyclic aromatic hydrocarbons (PAHs) have been determined in soils from urban and rural areas of Beijing. The rural area can be divided into plain and mountainous areas which are close to and relatively far from the urban area, respectively. Concentration of BC (5.83±3.05mgg−1) and BC/TOC concentration ratio (0.37±0.15) in Beijing’s urban soil are high compared with that in world background soils and rural soils of Beijing, suggesting the urban environment to be an essential source and sink of BC. Concentration of BC in the urban area decreases from the inner city to exterior areas, which correlates with the urbanization history of Beijing and infers accumulation of BC in old urban soils. Black carbon in Beijing soils mainly comes from fossil fuel combustion, especially traffic emission. Median PAH concentration in the urban area (502ngg−1) is one order of magnitude higher than that in the rural plain (148ngg−1) and mountainous area (146ngg−1) where PAHs are supposed to mainly come from atmospheric deposition from the urban area. Concentrations of BC correlate significantly with those of PAHs (p <0.01, except naphthalene) in the urban area and with those of heavier 4-, 5- and 6- ring PAHs (p <0.01) in the adjacent rural plain area, while there is no significant correlation with any PAH in the farther rural mountainous area. [ABSTRACT FROM AUTHOR]
Databáze: GreenFILE