title: Effect of reactive core mat application on bioavailability of hydrophobic organic compounds.
abstract: Sediment remediation techniques to limit the bioavailability of contaminants are of special interest due to related acute or chronic toxicities associated with sediment contaminants. Bioavailability in aquatic sediments can be particularly problematic due to their accessibility to food chain biota, and interactions with surface and ground water. The effect of a reactive core mat (RCM) containing organoclay on the bioavailability of hydrophobic organic compounds (HOCs) (i.e., PCBs and naphthalene) was studied using oligochaete worms (Lumbriculus variegatus). Sediment sampled from the Neponset River (Milton, MA) with 10 ppm background PCB contamination was used in the experimental study. The objective of this study is to investigate the difference in HOC concentration of worms exposed to: a) a grab sample of contaminated sediment (10.4% total organic carbon); and b) an initially clean mixture of sand and organic matter (the so-called biouptake layer), placed on top of the RCM-capped sediment during consolidation coupled solute transport experiments. In addition to the experimental data, the U.S. Army Corps of Engineers (USACE) biota-sediment accumulation factor (BSAF) database was validated and used to model biouptake of contaminants for certain cases. Results indicate that RCM capping reduced the average bioavailability of both PCBs and naphthalene by a factor of about 50. In fact, worms exposed to the RCM-protected biouptake layer show virtually the same HOC concentrations as those measured in the control worm samples.
authors.affiliation: Department of Civil and Environmental Engineering, Northeastern University, 400 Snell Engineering Center 360 Huntington Avenue, Boston, MA 02115, United States. meric.d@neu.edu
authors.forename: Dogus
authors.initials: D
authors.lastname: Meric
authors.forename: Sara M
authors.initials: SM
authors.lastname: Barbuto
authors.forename: Akram N
authors.initials: AN
authors.lastname: Alshawabkeh
authors.forename: James P
authors.initials: JP
authors.lastname: Shine
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Sheahan
mesh_terms: D000818:Animals; D004785:Environmental Pollutants / Q000737:chemistry* / Q000378:metabolism; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005374:Filtration; D020387:Food Chain; D019015:Geologic Sediments / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008962:Models, Theoretical; D009281:Naphthalenes / Q000737:chemistry / Q000378:metabolism; D009835:Oligochaeta / Q000378:metabolism*; D011078:Polychlorinated Biphenyls / Q000737:chemistry / Q000378:metabolism
chemical_list: D004785:Environmental Pollutants; D009281:Naphthalenes; C031721:naphthalene; D011078:Polychlorinated Biphenyls