Insights into the Long-Term Mass Discharge and Transformation of AFFF in the Unsaturated Zone
Abstract
The overall goals of this project were 1) to attain insight into the transformation and mass discharge of PFAS AFFF sources that reside in the unsaturated zone, and 2) to understand how these processes change over time with AFFF composition and mass. The overall approach consisted of installing a highly instrumented test cell an AFFF source area to monitor PFAS porewater concentrations as a function of moisture content and time with unsaturated zone. To provide insight into the mechanisms controlling the PFAS porewater concentrations, parallel set of bench-scale experiments were performed using site soils. Results of the study showed that a substantial fraction of the PFAS sorbed to the soil was typically resistant to desorption. Accounting for this fra as well as the mass of PFAS adsorbed to the air-water interface, PFAS porewater concentrations could be reasonably predicted. During flushing, decreases in PFAS porewater concentrations were reflective of what was observed in the bench-scale soil desorption isotherms.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 15, 2023
- Accession Number
- AD1216354
Entities
People
- Charles E Schaefer
- Christopher P Higgins
- David Lippincott
- Dung Tien Nguyen
- Jennifer Field
- Paul B. Hatzinger
Organizations
- CDM Smith
- Colorado School of Mines
- Oregon State University