Analysis on Distribution Characteristics of Soil Polycyclic Aromatic Hydrocarbons(PHAs) in a Large Coking Plant Site

Contents of 16 polycyclic aromatic hydrocarbons(PAHs) listed for prior control by USEPA in soil samples from a large coking plant site were detected. The characteristics of horizontal and vertical distribution of the 16 PAHs were discussed, while their ecological risk and sources were investigated. Results show that: (1) The total PAHs(ΣPAHs) contents ranged from 0-47 912.23 mg·kg^-1 with a maximum of ΣPAHs in indigenous coking area; Moreover, the contents of ΣPAHs in indigenous coking area, chemical production area were higher than those in other areas, which were mainly made up of naphthalene; Besides, the contents of ΣPAHs in < 3 m depth soil were higher than those in the subsoil. (2) The ecological risk sequence in different areas showed indigenous coking area> chemical production area> coking area> coal yard> office area. (3) The content ratios of total 2-3 rings PAHs and 4-6 rings PAHs revealed that the PAHs in chemical production area were mainly originated from coal tar leaking, while the PAHs in coking area, coal yard and office area mainly from soot deposition made by coking. In addition, the PAHs in indigenous coking area were mainly from both coal tar leaking and soot deposition.