PFAS adsorbent selection: The role of adsorbent use rate, water quality, and cost

Journal of Hazardous Materials, Год журнала: 2023, Номер 454, С. 131481 - 131481

Опубликована: Апрель 26, 2023

Язык: Английский

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Cross-national challenges and strategies for PFAS regulatory compliance in water infrastructure

Nature Water, Год журнала: 2023, Номер 1(12), С. 1004 - 1015

Опубликована: Дек. 15, 2023

Язык: Английский

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Application of Hydrothermal Alkaline Treatment to Spent Granular Activated Carbon: Destruction of Adsorbed PFASs and Adsorbent Regeneration

Environmental Science & Technology Letters, Год журнала: 2023, Номер 10(5), С. 425 - 430

Опубликована: Апрель 10, 2023

Granular activated carbon (GAC) adsorption is the most common technology applied to treat water contaminated with per- and polyfluoroalkyl substances (PFASs), but rapid exhaustion of media necessitates frequent replacement costly off-site thermal regeneration. Here, we extend application hydrothermal alkaline treatment (HALT), which uses strong alkali near-critical temperatures pressures (e.g., 350 °C, 16.5 MPa, 1 M NaOH) degrade mineralize PFASs, regeneration spent GAC. Mass balance experiments wherein a known mass perfluorooctanesulfonate (PFOS) was adsorbed onto GAC prior showed that HALT achieved >99% destruction PFOS 96 ± 4% defluorination no observed fluoro-organic intermediates [167 g L–1 GAC, NaOH, trxn = 400 min, 10–15 mg (g GAC)−1]. Treatment collected from field pilot study also effective range PFASs. Moreover, repeated cycles did not significantly affect specific surface area, similar isotherms for perfluoropentanoic acid were recorded virgin HALT-treated These findings suggest promising strategy on-site PFAS-contaminated other adsorbent may be an alternative practices.

Язык: Английский

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Influence of grain size, organic carbon and organic matter residue content on the sorption of per- and polyfluoroalkyl substances in aqueous film forming foam contaminated soils - Implications for remediation using soil washing

The Science of The Total Environment, Год журнала: 2023, Номер 875, С. 162668 - 162668

Опубликована: Март 8, 2023

A soil that was historically contaminated with Aqueous Film Forming Foam (AFFF) dry sieved into size fractions representative of those produced during washing. Batch sorption tests were then conducted to investigate the effect parameters on in situ per- and polyfluoroalkyl substances (PFAS) these different fractions: < 0.063 mm, 0.5 2 4 8 organic matter residues (SOMR). PFOS (513 ng/g), 6:2 FTS (132 ng/g) PFHxS (58 most dominant PFAS AFFF soil. Non-spiked, Kd values for 19 ranged from 0.2 138 L/Kg (log −0.8 2.14) bulk dependant head group perfluorinated chain length (spanning C4 C13). The increased decreasing grain increasing carbon content (OC), which correlated each other. For example, value silt clay (< 17.1 L/Kg, log 1.23) approximately 30 times higher compared gravel fraction (4 0.6 −0.25). highest (116.6 2.07) found SOMR fraction, had OC content. Koc 6.9 0.84) 1906 3.28) clay, indicating mineral composition also influenced sorption. results here emphasize need separate coarse-grained fine-grained fractions, particular SOMR, optimize washing process. Higher smaller indicate coarser soils are better suited

Язык: Английский

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Evaluation of commercial nanofiltration and reverse osmosis membrane filtration to remove per‐and polyfluoroalkyl substances (PFAS): Effects of transmembrane pressures and water matrices

Water Environment Research, Год журнала: 2024, Номер 96(2)

Опубликована: Янв. 30, 2024

Abstract Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are now widely found in aquatic ecosystems, including sources of drinking water portable water, due to their increasing prevalence. Among different PFAS treatment or separation technologies, nanofiltration (NF) reverse osmosis (RO) both yield high rejection efficiencies (>95%) diverse water; however, technologies affected by many intrinsic extrinsic factors. This study evaluated the carbon chain length (e.g., PFOA PFBA) two commercial RO NF membranes under operational conditions applied pressure initial concentration) feed solution matrixes, such as pH (4–10), salinity (0‐ 1000‐mM NaCl), organic matters (0–10 mM). We further performed principal component analysis (PCA) demonstrate interrelationships molecular weight (213–499 g·mol −1 ), membrane characteristics (RO NF), matrices, on rejection. Our results confirmed that size exclusion is a primary mechanism NF, well fact electrostatic interactions important when molecules have sizes less than pores. Practitioner Points Two were remove 10 PFAS. High transmembrane pressures facilitated permeate recovery RO. Electrostatic repulsion pore dominant mechanisms for removal. pH, ionic strength, Mechanisms with RO/NF explained PCA analysis.

Язык: Английский

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