Seemingly at odds with expected behavior the transport coefficient for soluble HOCs released from bed-sediment increases with increasing partitioning on to the particle phase. This apparent behavior is supported by two sets of data: one set is total PCBs plus five congeners from the Hudson River, NY and the other set is three HOCs tested in our laboratory microcosm. 7 The proposed mechanism for this behavior is particle bioturbation in the upper decimeters of the sediment bed, instantaneous desorption at the sediment-water interface followed by transport through the benthic boundary layer. A simple theoretical model equation is developed based on the mechanism and correlated to both data sets, The intrinsic transport coefficients extracted from the correlation parameters agree with published data on the particle mixing biodiffusion and the benthic boundary layer coefficients.
|Number of pages||4|
|Journal||ACS Division of Environmental Chemistry, Preprints|
|State||Published - Aug 20 2000|