Superfund Research Program
Sequestration Processes for Attenuation and Treatment of Arsenic and other Toxic Elements in Mine Waters
Air-water interface: The air-water interfaces present in geological media are critical for numerous applications in several fields. They are very important for biogeochemical processes that influence the transport and fate of contaminants at mining sites. The research team used a high-resolution imaging method similar to CAT scans combined with advanced 3-D image visualization to investigate the impact of soil surface structure on air–water interfacial area. The studies revealed the presence of air–water interfaces associated with water residing within macroscopic features such as pits and crevices on the surfaces of the solids. These microenvironments, which are not included in standard models, may have an impact on pore-scale physical and biogeochemical processes.
PFAS Contamination: The research team are developing and testing the theory governing the transport of per- and poly-fluoroalkyl substances (PFAS) in environmental systems. The research team’s work comprises: (1) the first investigations of the influence of adsorption at air-water and oil-water interfaces on the retention and transport of PFAS in porous media; (2) demonstration that these retention processes have significant impact on PFAS migration and storage in source zones; (3) development of the first comprehensive conceptual and mathematical models for PFAS retention in multi-phase systems; and (4) chemometric tools to develop the first quantitative structure-property relationship (QSPR) model for predicting interfacial adsorption coefficients for PFAS and, ultimately, retention and migration of PFAS in soil and groundwater systems. This information is critical for improving characterization of contaminated sites, examining soil leaching potential, assessing exposure risk, developing management and mitigation strategies, and implementing effective remediation efforts.