Partitioning of PAHs in pore water from mangrove wetlands in Shantou, China

• PAHs partitioning in pore water in sediment from mangrove wetlands was studied.
• POC could strongly adsorb low-ring PAHs.
• The trend of PAHs partitioning tend to suspended particulate matter.
• POC was a key factor in PAHs partitioning in mangrove wetlands.
• The model of Kp=Kocfoc+Kbcfbc may more accurately predict PAHs partitioning trend.

To investigate the trend of selected polycyclic aromatic hydrocarbons (PAHs) partitioning, fifteen pore water samples collected from the sediments of three mangrove wetlands were analyzed, and the partition coefficients and the partition model for the PAHs were determined by the correlation between Koc and octanol–water partition coefficient (Kow). The results revealed that the mean Kp values in inner mangrove wetlands were between 143 and 1031 L /Kg; the particulate organic carbon (POC) could strongly adsorb low-ring PAHs; the PAHs partitioning was on a obvious trend transported to particle phase. We suggest that the classic equilibrium model of organic carbon normalized (Kp=Kocfoc) may be used to predict the trend of the selected PAHs partitioning.