Dredged material has the potential to make up 12 percent of the cement manufactured in the United States.
To keep U.S. waterways clear, coastal management must dispose of 12 to 28 cubic tons of dredged material each year.
From Sediment to Cement
Research explores a sustainable method of transforming dredged sediment into concrete.
Challenge
Each year, between 12 and 28 million cubic yards of contaminated sediments are dredged from U.S. coastal waterways. Where to put these sediments is a formidable management challenge. With space for landfill becoming increasingly limited and expensive, coastal managers need sustainable options to address this issue.
Response
CICEET-sponsored researchers explored the viability of using contaminated sediments in the manufacture of cement—
potentially a management strategy suitable for adoption by the coastal community on a national scale. They characterized a range of dredged sediments in terms of their mineralogy and contaminant content. They then assessed the procedures and economics related to using dredged sediments in the manufacture
of cement.
Results showed that it is both technically and economically viable to use dredged sediment as a component of cement; particularly 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 percent of the raw materials for cement could be composed of dredged sediments.
They also found that using contaminated dredged material to manufacture cement can actually lower the amount of heavy metals in the final product, since mined materials used for cement often contain more heavy metals than contaminated marine sediments. Organic contaminants, such as PCBs and PAHs are removed during normal kiln firing process. The high chloride content of marine sediments did not affect the final product, but does require more often frequent cleaning of the manufacturing system.
Impact
Because these results are system dependent, researchers are pursuing pilot and full-scale test opportunities in order to confirm
the viability of this technology. The Port Authority of New York/New Jersey 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 approximately $55 per cubic yard at the minimum.
Learn More
Dr. Kevin Gardner
University of New Hampshire
T: 603.862.4334
E: kevin.gardner@unh.edu
Related Projects
In Situ Treatment of PCB-Contaminated Sediments Using Zero-Valent Iron [Bulletin]
Reusing Contaminated Dredged Sediments to Manufacture Cement [Bulletin]
Renourishing Marshes with Dredge Spoil [Bulletin]
Patented Technology for Stabilizing Metals in Dredged Sediment [Bulletin]
Development and Demonstration of Low Pressure Control Zone Contaminated Sediment Dredging Technology [Final Report]
Hydrogen-enhanced Remediation of Capped and Natural Sediments [Progress Report]
Enclosed Excavator for Contaminated Sediment Removal from Coastal Aquatic Environments [Progress Report]
Polychlorinated Biphenyl Remediation in Sediments: Pilot Scale Demonstration [Progress Report]
In Situ Remediation of PAH Contaminated Sediment [Progress Report]
A new technology uses ozone gas to treat polluted sediments in situ. [Project Brief]
Development of a Sediment Profile Imaging and Micro-sampling System (SPIMS) to Evaluate Bedded Sediment Quality [Progress report]
In situ Sediment Porewater Sensor to Detect Organic Micropollutants Using Solid Phase Microextraction (SPME) Technology [Progress Report]