Assessment of soil organic contamination in a typical petrochemical industry park in China

The concentrations of total petroleum hydrocarbons (TPH), n-alkanes (n-C-8 through n-C-40), and 16 polycyclic aromatic hydrocarbons (PAHs) in soils were determined to assess the level of organic contamination in soils from the Da-gang Petrochemical Industry Park with several big state-run enterprises, a recent rapid flourishing park in China. The results showed that the concentration of TPH in soil was high, up to 20 ng/g-12.8478 %; in particular, the content in most sites ranged from 1 to 2 %. Thus, it is clear that soil environment in the Da-gang Petrochemical Industry Park has been seriously polluted by TPH according to the Nemerow pollution index method. Furthermore, the average concentration of Sigma(n-C>(16) through n-C-34) in 30 sampling sites was above the maximum limit set for F3 under all the conditions in the Canada-wide standards for petroleum hydrocarbons (PHC CWS) with 43.33-93.33 % soil samples exceeding F3 standards, and n-alkanes possessing higher concentrations were proved much abundant alkanes in this study. Besides, the predominance of even n-alkanes and lower carbon preference index (CPI) demonstrated that n-alkanes in surface soils were mainly caused by anthropogenic inputs, while the concentration of Sigma(16)-PAHs was in the range of 1652.5-8217.3 ng/g and the BaA/(BaA + Chr) and Flu/(Flu + Pyr) ratios indicated that pyrogenic PAHs may be the dominant PAHs inmost soils with the contribution of petrogenic hydrocarbons in some sites.