Assessment of Mobilization Potential of Per- and Polyfluoroalkyl Substances for Soil Remediation.
Environ Sci Technol
; 56(14): 10030-10041, 2022 07 19.
Article
em En
| MEDLINE
| ID: mdl-35763608
ABSTRACT
This study investigated the mobilization of a wide range of per- and polyfluoroalkyl substances (PFASs) present in aqueous film-forming foams (AFFFs) in water-saturated soils through one-dimensional (1-D) column experiments with a view to assessing the feasibility of their remediation by soil desorption and washing. Results indicated that sorption/desorption of most of the shorter-carbon-chain PFASs (C ≤ 6) in soil reached greater than 99% rapidlyâafter approximately two pore volumes (PVs) and were well predicted by an equilibrium transport model, indicating that they will be readily removed by soil washing technologies. In contrast, the equilibrium model failed to predict the mobilization of longer-chain PFASs (C ≥ 7), indicating the presence of nonequilibrium sorption/desorption (confirmed by a flow interruption experiment). The actual time taken to attain 99% sorption/desorption was up to 5 times longer than predicted by the equilibrium model (e.g., â¼62 PVs versus â¼12 PVs predicted for perfluorooctane sulfonate (PFOS) in loamy sand). The increasing contribution of hydrophobic interactions over the electrostatic interactions is suggested as the main driving factor of the nonequilibrium processes. The inverse linear relationship (R2 = 0.6, p < 0.0001) between the nonequilibrium mass transfer rate coefficient and the Freundlich sorption coefficient could potentially be a useful means for preliminary evaluation of potential nonequilibrium sorption/desorption of PFASs in soils.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poluentes do Solo
/
Poluentes Químicos da Água
/
Fluorocarbonos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article