Sediment Management in the Anacostia and Grasse River
Funding
Hazardous
Substance Research Center, South & South East
Aluminum Company of
Collaborators
David Dzombak, CMU
Danny Reible, LSU
Publications
Lowry, G. V., Johnson, K. M.,
(2004) “Congener Specific PCB Dechlorination by Microscale and Nanoscale Zero-valent Iron in a Methanol/water solution.”
Environ. Sci.
Technol., 38(19) 5208-5216.
McDonough, K., Murphy, P. J., Olsta, J., Zhu,
Y., Reible, D., Lowry, G. V., Development and
Placement of a Sorbent-amended Thin Layer Sediment
Cap in the Anacostia River. Journal of Soil and Sediment Contamination,
an International Journal (in press).
Murphy, P., Marquette, A., Reible, D., Lowry,
G. V., “Predicting the Performance of Sediment Caps Amended with Sorbing Media”, Journal
of Environmental Engineering, 132 787-794.
Abstract
Releases of industrial contaminants such as polychlorinated
biphenyls (PCBs) have resulted in polluted water, soil, and sediment. Several costly ex situ remediation techniques
are available to treat these media. For
example, the US EPA is planning to dredge part of the Hudson River to remove
the PCB-contaminated sediment for ex situ treatment at a cost of nearly half a
billion dollars. Viable in situ
technologies capable of treating PCB-contaminated river sediments are needed. One attractive remedial alternative to
dredging is in situ capping. “Passive” subaqueous capping (e.g. sand or clean sediment) is a
proven sediment management tool providing physical isolation of
contaminants. However, this approach
does not reduce contaminant mass in the way that ex situ treatment does.
This research investigates the potential of “active” subaqueous caps as a sediment management tool capable of
sequestering and degrading PCBs in situ.
Previous research has shown that zero-valent
iron can be used in reactive barriers to dechlorinate
solvents such as trichloroethylene and carbon tetrachloride. Palladized iron
(Pd/Fe(0)) and nanoscale
iron are potentially capable of dechlorinating
PCBs. The potential for carbon-based
media (e.g. coke and activated carbon) to sequester PCBs and reduce their
bioavailability is high. Coal-derived
particles in sediment more strongly sorb hydrophobic
compounds than do particles of sand, silt, or clay. Furthermore, it has been shown that PAHs associated with coal particles are less bioavailable than sediment-bound PAHs. Therefore coke (an inexpensive material
derived from coal) or regenerated activated carbon may be good candidates as
“active” cap material for sequestering PCBs.
This investigation seeks to determine the best of these reactive and sorptive media based on feasibility of cap placement in the
field, ability to destroy and/or sequester PCBs, and materials cost.
Greg Lowry Home | Dept. Civil & Env. Engr.
Last Modified: June 2003