[Delivery and release of sediment PAHs during resuspension]

The resuspension of sediment after being disturbed is simulated by particle entrainment simulator (PES). The conclusions came out as follows. Sediment nature like granulometric composition and sediment PAHs richness markedly affected the release of PAHs. During the resuspension experiment, the total suspended solids (TSS) content of the overlying water showed significant correlation with particulate PAHs. The influence of the shear stress on the release of PAHs was reflected on two aspects. On one hand, its increase was accompanied with the increase of particulate PAHs. On the other hand, the PAHs enrichment effect of TSS decreased with the increase in the shear stress, since the stronger shear stress could draw more coarse particles with fewer PAHs into overlying water. The total PAHs in the overlying water continued to raise before stabilization at 120 min or 240 min. The particulate PAHs and dissolved PAHs answered each other very well. The release behavior among PAHs of different weight varied significantly. Due to the hydrophobic property of heavy weight PAHs, PAHs detected in overlying water were mostly 3-ring or 4-ring.