Distribution and sources of PAHs in the sediments of land-based sewage outlet to Zhanjiang bay and their environment significance

In order to investigate the sources inputs of PAHs into the Zhanjiang bay, this study has analyzed the compositions and spatial distributions of PAHs in the water way sediments of 11 main drainages into Zhanjiang bay.The results showed that ∑PAHs concentrations ranged from 28.1×10^-9 to 1533.7×10^-9 in 11 sediment samples, and urban samples showed higher level of PAHs concentration than that of rural and suburban samples.This suggests that the inputs of PAHs from urban areas may be the major source of PAHs in Zhanjiang bay.The composition and ratios of PAHs isomers showed that PAHs were mainly derived from the combustion of coal, biomass and petrol, as well as petroleum related pollutions.It was also showed that the concentrations, spatial distribution and sources of PAHs were consistent with the energy consumption structure and agriculture economical statue of Zhanjiang district.Therefore, this study provided useful data for the economic development planning, marine environmental management and POPs pollution control of Zhanjiang bay area.