TY - JOUR
T1 - Transport of PFOS in aquifer sediment
T2 - Transport behavior and a distributed-sorption model
AU - Wang, Yake
AU - Khan, Naima
AU - Huang, Dandan
AU - Carroll, Kenneth C.
AU - Brusseau, Mark L.
N1 - Funding Information:
This research was supported by the NIEHS Superfund Research Program (grant # P42 ES04940 ). Additionally, we appreciate the support from the Department of Energy (DOE) Minority Serving Institution Partnership Program (MSIPP) managed by the Savannah River National Laboratory and from NMSU's Agricultural Experiment Station Competitive Operations Grant Award. We thank the reviewers for their helpful comments.
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/7/20
Y1 - 2021/7/20
N2 - The objectives of this research were to examine the transport of perfluorooctane sulfonic acid (PFOS) in aquifer sediment comprising different geochemical properties, and to compare the behavior to that observed for PFOS transport in soil and sand. PFOS retardation was relatively low for transport in all aquifer media. The PFOS breakthrough curves were asymmetrical and exhibited extensive concentration tailing, indicating that sorption/desorption was significantly nonideal. The results of model simulations indicated that rate-limited sorption/desorption was the primary cause of the nonideal PFOS transport. Comparison of PFOS transport in aquifer media to data reported for PFOS transport in two soils and a quartz sand showed that PFOS exhibited more extensive elution tailing for the soils, likely reflecting differences in the relative contributions of various media constituents to sorption. A three-component distributed-sorption model was developed that accounted for contributions from soil organic carbon, metal oxides, and silt + clay fraction. The model produced very good predictions of Kd for the five media with lower soil organic‑carbon contents (≤0.1%). Soil organic carbon was estimated to contribute 19–42% of the total sorption for all media except the sand, to which it contributed ~100%. The contribution of silt + clay ranged from 51 to 80% for all media except the sand. The only medium for which the contribution of metal-oxides was significant is Hanford, with an estimated contribution of 15%. Overall, the results of the study indicate that sorption of PFOS by these aquifer media comprised contributions from multiple soil constituents.
AB - The objectives of this research were to examine the transport of perfluorooctane sulfonic acid (PFOS) in aquifer sediment comprising different geochemical properties, and to compare the behavior to that observed for PFOS transport in soil and sand. PFOS retardation was relatively low for transport in all aquifer media. The PFOS breakthrough curves were asymmetrical and exhibited extensive concentration tailing, indicating that sorption/desorption was significantly nonideal. The results of model simulations indicated that rate-limited sorption/desorption was the primary cause of the nonideal PFOS transport. Comparison of PFOS transport in aquifer media to data reported for PFOS transport in two soils and a quartz sand showed that PFOS exhibited more extensive elution tailing for the soils, likely reflecting differences in the relative contributions of various media constituents to sorption. A three-component distributed-sorption model was developed that accounted for contributions from soil organic carbon, metal oxides, and silt + clay fraction. The model produced very good predictions of Kd for the five media with lower soil organic‑carbon contents (≤0.1%). Soil organic carbon was estimated to contribute 19–42% of the total sorption for all media except the sand, to which it contributed ~100%. The contribution of silt + clay ranged from 51 to 80% for all media except the sand. The only medium for which the contribution of metal-oxides was significant is Hanford, with an estimated contribution of 15%. Overall, the results of the study indicate that sorption of PFOS by these aquifer media comprised contributions from multiple soil constituents.
KW - PFAS
KW - Perfluoroalkyl substances
KW - Retardation
KW - Sorption
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U2 - 10.1016/j.scitotenv.2021.146444
DO - 10.1016/j.scitotenv.2021.146444
M3 - Article
C2 - 33740555
AN - SCOPUS:85102567611
VL - 779
JO - Science of the Total Environment
JF - Science of the Total Environment
SN - 0048-9697
M1 - 146444
ER -