Abstract:
In order to understand the pollution characteristics and distribution of PAHs in farmland soil of peri-urban areas, a case study of Zhougang of Nanjing was carried out to investigate the content, spatial distribution characteristics and sources of 15 optimal PAHs components in topsoil. Results showed that 14 PAHs were detected (Ace was not detected), and most of them were high loop (4-6 rings) PAHs. The total content of PAHs in farmland soil ranged from 24.49 to 750.04 μg kg
−1 with an average value of 230.89 μg kg
−1. About 48.28% of farmland soil in this study area was polluted. Compared with the other farmland soil in China, the PAHs contents in this study area were at medium and low levels. The spatial trend analysis showed obvious increasing or decreasing regularity in east-west and north-south direction for the total content of 14 PAHs. According to the spatial distribution characteristics, the 14 PAHs contents in the farmland soil were significantly different and overall showed a decline from the northeast to southwest areas. There was a certain accumulation of PAHs at some points, where existed local point source pollution. The results of principal component analysis (PCA) and multiple linear regression showed that the main sources of 14 PAHs in the study area were coal and biomass combustion, followed by the combustion of gas and diesel oils, with contribution rates of 71% and 29%, respectively, which were closely related to the local industrial development level.