Remobilization of polycyclic aromatic hydrocarbons during the resuspension of Yangtze River sediments using a particle entrainment simulator

Remobilization of 16 polycyclic aromatic hydrocarbons (PAHs) during sediment resuspension was investigated using a particle entrainment simulator at shear stress from 0.2 to 0.5 N m−2, typical of the energy levels present in many tidally driven aquatic environments. The results suggested that desorption from the entrained particles was the primary source of dissolved PAHs. ∑PAHs concentrations in particles on volume normalization increased about four times. However, on mass weight basis, ∑PAHs concentrations decreased from 6039.74 ± 138.28 μg kg−1 to 1665.39 ± 112.26 μg kg−1. The same trend was observed for individual PAHs. Dissolved concentrations of PAHs demonstrated significant differences depending on molecular weight and applied shear. The distribution of PAHs between particle and water phase suggested that for three-ring PAHs, the amounts of PAHs in particles were higher than the predicted values during our experiments. This might be due to presence of another active sorbent.