Enrichment of marine sediment colloids with polychlorinated biphenyls (PCBs)

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:242400

Burgess, R M ^[1]; Brown, W A ^[2]; Quinn, J G ^[3]

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1. Environmental Protection Agency, Narragansett, RI (United States). Environmental Research Lab.
2. Science Applications International Corp., Narragansett, RI (United States)
3. Univ. of Rhode Island, Narragansett, RI (United States). Graduate School of Oceanography

Marine sediments represent a sink for a variety of anthropogenic compounds including pesticides, 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 (i.e., the bioavailable form) 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 a new physical inclusion reverse phase chromatography technique. 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 CDC quantity or quality. These empirical data illustrate the complex interaction between hydrophobicity and natural organic carbon which ultimately can be used to quantify contaminant bioavailability.

• OSTI ID: 242400
• Report Number(s): CONF-9511137--; ISBN 1-880611-03-1
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
BIOLOGICAL AVAILABILITY
CARBON SINKS
PHASE STUDIES
POLYCHLORINATED BIPHENYLS
SEAS
SEDIMENTS
WATER CHEMISTRY
WATER POLLUTION