Uptake of perfluorinated alkyl acids by crops: results from a field study

Abstract

Variability of plant uptake of PFAAs from soil is explored with measured uptake factors for 13 PFAAs in 4 crops.

Predicting Concentration- and Ionic-Strength-Dependent Air–Water Interfacial Partitioning Parameters of PFASs Using Quantitative Structure–Property Relationships (QSPRs)

“…Results from our analysis demonstrate that both the "C18" and "no C18" models are more consistent with the Felizeter et al 2021 33 field data when rate-limited sorption and competitive sorption processes are considered for all components present in the mixture (SI 7). While the "no C18" model provides a better goodness of fit for the training data (Figure 4a,b), the "C18" model was more consistent for the PFAAs in the Felizeter et al 2021 33 data (SI 7).…”

“…Further validation of both QSPR models was conducted using an equilibrium mass balance method described in Brusseau and Guo 2022 and data from Felizeter et al 2021 in SI 7. Brusseau and Guo concluded a Langmuir-based QSPR model for predicting air–water interfacial partitioning provided a good prediction for selected PFAAs using data from Felizeter et al 2021 . However, Brusseau and Guo did not account for the significant effects of rate-limited sorption in unsaturated media with high organic matter ,,,,, or competitive sorption of PFAS mixtures at relatively high concentrations, ,, which are almost certainly present in the Felizeter et al 2021 data.…”

“…We reproduced the mass balance using the Felizeter et al 2021 data (using K ia values predicted by both the “C18” and “no C18” QSPR models) and recreate the Brusseau and Guo 2022 analysis using a molar-volume-based QSPR approximation of K ia from Brusseau and Van Glubt (Figures S.6–S.8). Results from our analysis demonstrate that both the “C18” and “no C18” models are more consistent with the Felizeter et al 2021 field data when rate-limited sorption and competitive sorption processes are considered for all components present in the mixture (SI 7). While the “no C18” model provides a better goodness of fit for the training data (Figure a,b), the “C18” model was more consistent for the PFAAs in the Felizeter et al 2021 data (SI 7).…”

“…However, the increase in air−water interfacial partitioning could also be due to the interactions among co-solutes. 46,48,49 Further validation of both QSPR models was conducted using an equilibrium mass balance method described in Brusseau and Guo 2022 82 and data from Felizeter et al 2021 33 in SI 7. Brusseau and Guo concluded a Langmuir-based QSPR model for predicting air−water interfacial partitioning provided a good prediction for selected PFAAs using data from Felizeter et al 2021.…”

“…Indeed, the most appropriate approach for modeling PFAS sorption at the air–water interfaces is currently the subject of some debate, ,,,, particularly below the CRC of each PFAS. As most field sites have PFAS porewater concentrations that are well below the CRC, − determining the accurate isotherm for describing interfacial sorption at low PFAS concentrations is of critical importance. Recent studies ,,, suggest that a Freundlich isotherm, for which PFAS sorption to the air–water interface is dependent upon PFAS concentration both above and below the CRC, is appropriate for air–water interfacial sorption.…”