Three shear turbulence resuspension mesocosms (STORM tanks) were used to examine the release of polychlorinated biphenyls (PCBs) from resuspended Hudson River sediment.Twenty-two percent of the resuspended PCBs desorbed after 2 h,and 35 +-8 of PCBs were in the dissolved phase after apparent steady state was reached in 2 days.After the first resuspension event,the solids were allowed to settle and the quiescent time was varied to determine whether the labile pool of PCBs is recharged during sediment consolidation.The steady-state log K_(oc) values for the third subsequent resuspension were higher than for the first event due to lower dissolved PCB concentrations;the particulate PCB concentrations were constant between events.With 1 day of consolidation between resuspension events,the dissolved concentration of all congeners decreased an average of 8 +- 5 between subsequent resuspension events.With 4 days between events,only the dissolved pentachlorinated PCBs decreased significantly p = 0.002),suggesting that the easily desorbable PCBs recharge when there is sufficient time between resuspension events.
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