Exploring the influence of water exchange on the distribution of polycyclic aromatic hydrocarbons in marine sediments by numerical calculation model

•Delft3D was used to build a multi-process coupled dynamic model of PAHs.•The model was used to calculate the water exchange time of PAHs in Liaodong Bay.•The closer the area next to the bay-mouth, the shorter the water exchange time is.•Concentration of PAHs in sediment and its water exchange rate has negative correlation.