Application of Silicone Rubber Passive Samplers to Determine the Availability of Polycyclic Aromatic Hydrocarbons (PAHs) in Marine Sediments

摘要

Polycyclic aromatic hydrocarbons (PAHs) in marine systems readily become adsorbed onto similarly hydrophobic organic matter found in sediment. Subsequent desorption, exchange with the water phase, and degradation of these compounds from the sediment is inadequately understood. Traditionally, possible risks of PAH contamination in marine environments have been assessed based upon total concentrations found in sediments. Direct sediment analyses, however, do not necessarily reflect how much of the sediment-bound PAH is available, or could become available, for uptake by organisms living in the water. Thus, the purpose of this laboratory-scale Masters Thesis research project was to investigate the bioavailability of PAHs in marine sediments in relation to the total sediment concentration. The ultimate goal would be to assist in the development of a passive sampling device that would allow for a more accurate risk assessment data set when reviewing license applications for remote disposal of harbor dredge sediments. For all groups of PAHs, in every sediment sample analyzed in this study, the waterextractable sediment concentration determined from silicone rubber extract data was found to be less than the total concentration extracted directly from the sediment. This supports the assertion that a fraction of PAHs in marine environments is bound to the sediment and, therefore, is not readily available for exchange into the pore water.