PCBs are among the most persistent and bioaccumulative substances
and lead to the majority of fish consumption advisories nationwide.
Lack of in-situ treatment ability has resulted in the need to dredge
hotspots, as in the upper Hudson River among other coastal, inland,
and riverine locations.
The technique being investigated works by the corrosion of colloidal
(~50 nm diameter) Fe0, which reduces and dechlorinates PCBs. Successful
treatment of PCBs in sediments has been demonstrated in the laboratory;
further work is continuing to parameterize this process to determine
its feasibility in the field.
Scanning electron micrograph showing
colloidal Fe0; the scale in the lower right indicates the
diameter of each particle is on the order of 50 nm.
This scanning electron micrograph shows
colloidal Fe0 (bright spots) deposited onto a silica sand
media. Depositing Fe0 onto a sand support prior to mixing
into sediments is one possible introduction method.
Dr. Kevin Gardner
Center for Contaminated Sediments Research
336 Environmental Technology Building
University of New Hampshire
Durham, NH 03824
(603) 862-4334 [phone]
(603) 862-3957 [fax]