||This study determined the distribution of particulate polycyclic aromatic hydrocarbons (PAHs) in Gaoping coastal area. In addition, principal component analysis (PCA), hierarchical cluster analysis (HCA) and chemical fingerprinting were performed to investigate the possible sources of PAHs in this area. |
The total concentrations of 36 analyzed PAHs (ΣPAHs) varied from 0.20 to 34.4 ng/L in the water column with the mean value of 2.53±2.19 ng/L. Higher ΣPAHs values were observed in Gaoping Submarine Canyon in November 2012 due to the higher contents of suspended particles. ΣPAHs on suspended particles varied from 137 to 4270 ng/g with the mean value of 1010±825 ng/g. Higher values occurred at stations W05, W07, W08, W10 and W11 whose particles were finer and bearing higher sorption capacity in general. In addition, PAH concentrations were found significantly correlated with organic carbon content (R=0.30, P<0.05). Relatively, particulate PAH concentrations in Gaoping coastal area were at lower level comparing with other areas in the world.
Results from chemical fingerprinting, HCA and PCA indicate that particulate PAHs in the study area were mainly from petrogenic sources and petroleum combustion in May and November 2012, from petroleum combustion and pyrogenic sources in September 2012; while from pyrogenic sources in March 2013. The characteristics of bottom suspended particles in Gaoping Submarine Canyon were different from other samples. The tidal current in the canyon might cause those particles distinct from other areas in source recognition. In addition, the surface particles exhibited stronger signal from terrestrial input and atmosphere deposition.