Release of polycyclic aromatic hydrocarbons from Yangtze River sediment cores during periods of simulated resuspension.

The role of resuspension duration on release of 16 PAHs was measured experimentally using a particle entrainment simulator (PES). Three sediment cores were resuspended for 12h at 0.2 and 0.5 N m(-2). PAHs in water column and total suspended solids (TSS) were monitored at intervals. After 0.25 h of resuspension, PAH release was on average 42% of their concentrations after 12h of resuspension, indicating fast release of PAHs from sediments in an initial short time. Moreover, PAHs released faster at 0.5 N m(-2) than at 0.2N m(-2); low molecular weight PAHs (2-3-ring) released faster than median molecular weight (4-ring) PAHs. PAH concentrations in TSS showed generally increase with time and differences in magnitudes based on sediment type and energy. Overall, the composition of sediments is the major factor in determining the amount of released PAHs, more so than the level of resuspension energy applied.