PARENT SESSION
TA6 - Bioavailability Issues in Bioremediation of Contaminated Sediments
Chair: Tabak, Henry1, 1 U.S. EPA, Cincinnati, OH
Co-chair: Lazorchak, Jim2, 2 U.S. EPA, Cincinnati, OH
8:00 AM to 12:00 PM - Tuesday, 19 November 2002
Room Ballroom B
(378) PCB bioaccumulation from marine sediments following in situ remediation application of coal-derived particles.
Luthy, Richard1, Bridges, Todd2, Millward, Rod*,3, Ghosh, Upal1, Zimmerman, John1, Ahn, Sungwoo1, 1 Dept. of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA2 Engineering Research and Development Center, US Army Corps Waterways Experiment Station, Vicksburg, MS, USA3 ERDC-USACE. Analytical Services Inc., Vicksburg, MS, USA
ABSTRACT- We investigate the feasibility of in situ stabilization/containment of polychlorinated biphenyls (PCBs) in sediments through the addition of low-cost, coal-derived sorbent material, such as coke or regenerated activated carbon. Our past research has shown that coal-derived materials are strong sorbents that may capture organic contaminants, making them unavailable to the aqueous phase and for biological uptake. Therefore, we propose that the addition of such material is a potentially cost-effective, in situ, non-removal, management strategy. Coal-derived particulate sorbent media are two-to-three orders of magnitude more efficient in sequestering organic contaminants compared to natural sediment organic matter. Thus, the addition of clean coal-derived sorbents to contaminated sediments may reduce ecosystem exposure by reducing contaminant bioavailability and flux between sediments and pore water. We present toxicological data addressing the acute and subacute effects of coke addition on a polychaete worm (Neanthes arenaceodentata) and amphipod (Leptocheirus plumulosus), assessing any detrimental effect due to the proposed remediation technique. Results indicate that coke had no observable effect on either test organism. We explain the use of multiple tools that are leading to a mechanistic understanding of the effects of coal-derived sorbent material addition on PCB bioavailability and PCB bioaccumulation, including techniques that relate bioaccumulation effects to underlying physicochemical partitioning processes. We will present results from short-term sediment contact experiments with coke and activated carbon on PCB body burdens in the test species and discuss the implications of these findings in support of continued research on this potential remediation technique.
Key words: organic, polychlorinated, biphenyl