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Reusing Contaminated, Dredged Sediments
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Project Title: Development of Beneficial Use Alternatives for the Management of Dredged, Contaminated Sediments
Research Locations: Hudson River, NY - Narragansett Bay, RI
Last Update: 8-28-02
Each year, between 12 and 28 million cubic yards of contaminated sediments are dredged from US coastal waterways. Disposal of these sediments is a formidable management challenge. The goal of this project is to investigate the viability of using contaminated sediments in the manufacture of cement. This research examines the fate of contaminants used for cement as well as the overall performance of cement containing dredged sediments. If successful, the result will be an innovative management strategy suitable for adoption by the coastal community on a national scale.
Approach
Foremost among the research objectives of this project are:
- characterize a range of dredged sediments in terms of their mineralogy and contaminant content
- assess the procedures that will be necessary to use dredged sediments in the manufacture of cement
- assess the economics of using dredged sediments in the manufacture of cement
Results
In general, the results show that it is both technically and economically
viable to use dredged sediments as a component of
cement. Specifically:
- sampled dredged material contained large quantities of silicon,
iron and aluminum oxides, three of the four main ingredients in
cement. Researchers estimate that as much as 12% of the raw
materials for cement could be composed of dredged sediments.
- using contaminated dredged material in the manufacture of cement can actually lower the amount of heavy metals in the final product, because mined materials used for cement often contain more heavy metals than contaminated marine sediments.
- organic contaminants (e.g., PCBs, PAHs) are volatilized in the normal kiln firing process.
Chloride Concerns
The high chloride content of marine sediments doesn’t affect the
final product, but it can lead to problematic scaling within the
kilns. To avoid this, manufacturers would have to shut down and
clean the system more often.
What About the Cost?
The Port Authority of New York/New Jersey (PANYNJ) commissioned
an economic analysis of using contaminated sediments in
cement manufacture. The analysis showed that it would cost them
between $15 and $25 per cubic foot to prepare dredged material
for cement manufacture: (Current options for dredged material
disposal cost PANYNJ around $55 per cubic yard at the minimum.)
Scaling Up
Because these results are system dependent, researchers are pursuing
pilot and full-scale test opportunities in order to confirm
the viability of this technology.
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Project Coordinator
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Kevin Gardner University of New Hampshire (603) 862-4334 kevin.gardner@unh.edu |
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Start -End Date:
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09/01/2000 - 09/01/2002
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NERR Reserve(s):
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Hudson River, NY - Narragansett Bay, RI
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| For more information: |
Dolores Jalbert Leonard Phone: (603) 862-3685 Email: dolores.leonard@unh.edu |