Enrichment of marine sediment colloids with polychlorinated biphenyls (PCBs)
- Environmental Protection Agency, Narragansett, RI (United States). Environmental Research Lab.
- Science Applications International Corp., Shalimar, FL (United States)
Marine sediments represent a sink for a variety of anthropogenic compounds including polycyclic aromatic hydrocarbons, and PCBs. Despite acceptance of this principle, the actual geochemical fate of contaminants in sediments is not fully known. Consequently, understanding the fate and bioavailability of sediment associated contaminants is compromised. Physical separation techniques (e.g., filtration) allow gross determinations of particulate and interstitial water concentrations of contaminants. But quantification of the freely dissolved contaminants remains constrained by technical difficulty, and as a result these concentrations are often estimated rather than empirically determined. In this presentation, the three phase distribution of approximately 40 PCB congeners, in a marine sediment core from a severely contaminated site, are reported. All three phases; freely dissolved, colloidal and particulate, were empirically determined using reverse phase chromatography with size selected C{sub 18}. Distributions of PCB congeners varied by degree of chlorination, solubility, and colloidal organic carbon (COC) concentration. Low molecular weight congeners, di-Cl, tri-Cl and tetra-Cl, were approximately 20, 40 and 60% colloidal bound, respectively, while heavier congeners (i.e., penta-Cl, hexa-Cl, and hepta-Cl) were approximately 85% colloidal bound. Regardless of chlorination or solubility, all congeners demonstrated an increased colloidal association with increasing COC. Colloidal and particulate partition coefficients (K{sub COC} and K{sub OC}) appear to change in magnitude also as a function of COC quantity or quality.
- OSTI ID:
- 460499
- Report Number(s):
- CONF-961149--
- Country of Publication:
- United States
- Language:
- English
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