Northeastern University (Sheahan)

Summary

Contaminated sediments present a global public health challenge that requires new, innovative approaches. Dr. Thomas Sheahan is developing a new type of permeable, reactive geocomposite for remediation and management of contaminated sediments. The barrier, which consists of one or more filtering layers surrounding a reactive layer, can be placed on the sediment surface. By immobilizing and/or neutralizing contaminants, the composite has the potential to minimize further contaminant migration and, in subaqueous environments, contaminant resuspension and diffusion into the overlying water column. This will limit the bioavailability of contaminants and bioaccumulation in aquatic food webs, which can be a pathway for human exposure via ingestion.

Dr. Sheahan is working to develop a comprehensive understanding of how the geocomposite would function most effectively in long-term field applications for different combinations of sediment types, sediment contaminants and pore fluid environments; and how effectively the composite can reduce ecological and human health risks associated with sediment-bound contaminants.

This research effort will entail:

• Sediment characterization including physical, chemical, biological and consolidation testing
• Batch chemical testing to assess and optimize reactivity between target contaminants and the composite reactive amendments
• Bench scale tests to model the sediment-composite-benthic system
• Modeling of the process, accounting for seepage, consolidation, dispersion and reactivity due to adsorption and transformation.