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CHEMICAL DYNAMICS OF HYDROPHOBIC ORGANIC CONTAMINANTS DURING RESUSPENSION
Citation:
Latimer, J S., W Davis, AND D J. Keith. CHEMICAL DYNAMICS OF HYDROPHOBIC ORGANIC CONTAMINANTS DURING RESUSPENSION. Presented at Estuarine Research Federation 95 Conference, Corpus Christi TX, November 12-15, 1995.
Description:
Laboratory experiments were designed to study the chemical-particle dynamics of toxic hydrophobic organics during resuspension episodes using a particle entrainment simulator (PES). The purpose was to obtain insight into chemical transport mechanisms during resuspension. Information on these mechanisms would be useful in assessing effects of dredging, dredge spoil disposal, or ordinary sediment mobilization in urban estuaries. Sediments from Black Rock Harbor, CT and two sites in Narragansett Bay, RI, representing a range of contaminant and bulk sediment properties, were subjected to experiments using the PES. Results indicate that on a volume normalized basis contaminant concentrations in the water column became elevated as applied shear increased from 2 to 5 dynes cm-2; however, on a mass and organic carbon normalized basis, the loadings decreased with increasing applied shear. The differences
observed were traced to textural and chemical properties in the bulk sediments. It was concluded that the distribution of the contaminants was likely related to the amount of, and contaminant load on, material entrained during resuspension events. These observations are the result of: (1) dilution of contaminants from depleted coarse grained material, (2) fortification from more highly loaded coarse grained materials (in the case of PAHs with log Kow >6) and (3) the effects from fine grained, highly enriched material.