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Role of sediment resuspension in the remobilization of particulate-phase metals from coastal sediments

Environmental Science and Technology

By:
, , , and
DOI: 10.1021/es061770z

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Abstract

The release of particulate-phase trace metals due to sediment resuspension has been investigated by combining erosion chamber experiments that apply a range of shear stresses typically encountered in coastal environments with a shear stress record simulated by a hydrodynamic model. Two sites with contrasting sediment chemistry were investigated. Sediment particles enriched in silver, copper, and lead, 4−50 times greater than the bulk surface-sediment content, were the first particles to be eroded. As the shear-stress level was increased in the chamber, the total mass eroded increased, but the enrichment of these trace metals fell, approaching the bulk-sediment content. From the temporal distribution of shear stress generated by the hydrodynamic model for a site in Boston Harbor, resuspension fluxes were estimated. The erosion threshold of this site is exceeded during spring tides, releasing the particles enriched in trace metals into the water column. Due to the higher trace metal content and the regularity of resuspension, low-energy resuspension events (up to a shear stress of 0.2 N/m2) contribute up to 60% of the resuspension metal flux in an average year. The estimated annual quantity of copper and lead resuspended into the water column is higher than estimates of the total riverine flux for these metals. These results indicate that sediment resuspension is a very important mechanism for releasing metals into the water column and provide new insight into the chemical and physical processes controlling the long-term fate of trace metals in contaminated sediments.

Geospatial Extents

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Role of sediment resuspension in the remobilization of particulate-phase metals from coastal sediments
Series title:
Environmental Science and Technology
DOI:
10.1021/es061770z
Volume
41
Issue:
7
Year Published:
2007
Language:
English
Contributing office(s):
Coastal and Marine Geology Program
Description:
7 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Environmental Science and Technology
First page:
2282
Last page:
2288
Country:
United States
State:
Massachusetts
Other Geospatial:
Hingham Bay;Massachusetts Bay