FLUORANTHENE K-DOC IN SEDIMENT PORE WATERS

When calculating concentrations of truly dissolved hydrophobic organic contaminants (HOCs) in sediment pore water, a common assumption is that the partition coefficient between pore water and colloidal plus dissolved organic carbon (K-DOC) equals the partition coefficient between pore water and sediment total organic carbon (K-DOC). This study examined the K-DOC of fluoranthene in pore water from 11 sediments. Truly dissolved fluoranthene was separated from DOG-associated fluoranthene by partitioning on C-18 Sep Paks. Measured values of K-DOC were not constant over the 11 sediments examined, and were over or underestimated by assuming that K-DOC = K-oc. Current models used to predict the fate of HOCs may require modification to account for the observed difference between K-DOC and K-OC.