Trifluoroacetic Acid: Toxicity, Sources, Sinks and Future Prospects

Sustainability, Год журнала: 2024, Номер 16(6), С. 2382 - 2382

Опубликована: Март 13, 2024

Trifluoroacetic acid (TFA) is a known and persistent pollutant in the environment. Although several direct anthropogenic sources exist, production from atmospheric degradation of fluorocarbons such as some hydrofluorocarbons (HFCs) has been source for time. The current transition HFCs to HFOs (hydrofluoroolefins) beneficial global warming viewpoint because are much shorter-lived pose smaller threat terms warming, but fraction converted into TFA higher than seen corresponding region which produced close source. Therefore, it timely review role Earth’s This considers its toxicity, removal processes, measurement variety environments, future prospects. New model integrations used quantify impacts uncertainties on levels using Henry’s Law constant range gas-phase kinetic parameters chosen reaction OH radicals with representative HFO (HFO-1234yf). Model runs suggest that surface concentrations vary by up 10% based data could be 25% previously modelled values depending analysis adopted. estimates require updating warrants further investigation. toxicity appears low, studies wider animal plant types required.

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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Spontaneous Degradation of the “Forever Chemicals” Perfluoroalkyl and Polyfluoroalkyl Substances (PFASs) on Water Droplet Surfaces

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Апрель 8, 2024

Because of their innate chemical stability, the ubiquitous perfluoroalkyl and polyfluoroalkyl substances (PFASs) have been dubbed "forever chemicals" attracted considerable attention. However, stability under environmental conditions has not widely verified. Herein, perfluorooctanoic acid (PFOA), a used detected PFAS, was found to be spontaneously degraded in aqueous microdroplets room temperature atmospheric pressure conditions. This unexpected fast degradation occurred via unique multicycle redox reaction PFOA with interfacial reactive species on droplet surface. Similar observed for other PFASs. study extends current understanding fate chemistry PFASs provides insight into aid development effective methods removing

Язык: Английский

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A Comprehensive Review of Novel Adsorbents for Per- and Polyfluoroalkyl Substances in Water

ACS ES&T Water, Год журнала: 2024, Номер 4(4), С. 1191 - 1205

Опубликована: Март 8, 2024

Recent literature has seen a significant surge in studies focusing on new adsorbent materials for per- and polyfluoroalkyl substances (PFASg), class of contaminants found natural waters worldwide that pose considerable threat to human environmental health. Despite growing interest, the fundamental mechanisms PFAS adsorption these are not fully understood, thus hindering progress developing effective solutions removal. This Review aims bridge knowledge gap by offering critical appraisal recent innovations specifically designed treating PFAS. Strategies aimed at enhancing nanopore capacity or introducing anion-exchange capabilities have shown promise. Innovative such as carbon nanotubes, graphene, graphene oxide evaluated. Modified clay-based silica-based adsorbents demonstrated efficacy removing PFAS, driven hydrophobic effect, Coulombic interactions, electrostatic interactions. Polymers, ranging from types synthetic variants, promise removal across wide pH range. We discuss including F–F ion-pair adsorption, ion exchange chemically thermally modified provide general guideline design adsorbents. offers holistic view advances related materials.

Язык: Английский

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Critical evaluation of hyperspectral imaging technology for detection and quantification of microplastics in soil

Journal of Hazardous Materials, Год журнала: 2024, Номер 476, С. 135041 - 135041

Опубликована: Июнь 26, 2024

Язык: Английский

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Photocatalyst degradation of perfluorooctanoic acid in water: Mechanisms, approaches, and perspectives

Separation and Purification Technology, Год журнала: 2024, Номер 338, С. 126503 - 126503

Опубликована: Янв. 25, 2024

Язык: Английский

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Headgroup Dependence and Kinetic Bottlenecks of Gas-Phase Thermal PFAS Destruction

ACS ES&T Engineering, Год журнала: 2025, Номер unknown

Опубликована: Янв. 2, 2025

Recent studies of thermal PFAS destruction have reported seemingly incoherent temperatures and products, often because decomposition pathways are highly dependent on the respective experimental system. Here, we applied accurate DLPNO–CCSD(T) coupled cluster calculations to isolate identify major processes during in gas phase, with relevance incineration, oxidation, other treatment technologies which their volatile products desorb into phase. All investigated perfluoroalkyl acids decompose via unimolecular headgroup loss, either through HF elimination or homolytic bond cleavage as a function type. In contrast, all fluorotelomers undergo initial hydrogen abstraction from characteristic C2H4 moiety by hydroxyl radicals under representative incineration conditions, followed radical decomposition. Subsequent formation perfluoroalkanes, including CF4, can then be prevented supplying sufficient donors such hydrocarbon fuel water well scavenging released fluorine. This leads generation stable 1H-perfluoroalkanes. While parent proceeds at gas-phase ≤700 °C, carbon–carbon 1H-perfluoroalkanes requires up ∼950 °C 2 s residence time, making this step kinetic bottleneck way complete mineralization.

Язык: Английский

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Accurate Enthalpies of Formation for PFAS from First-Principles: Combining Different Levels of Theory in a Generalized Thermochemical Hierarchy

ACS Physical Chemistry Au, Год журнала: 2024, Номер 4(3), С. 247 - 258

Опубликована: Фев. 27, 2024

The enthalpies of formation are computed for a large number per- and poly fluoroalkyl substances (PFAS) using connectivity-based hierarchy (CBH) approach. A combination different electronic structure methods used to provide the reference data in hierarchical manner. ANL0 method, conjunction with active thermochemical tables, provides smaller species subchemical accuracy. Coupled-cluster theory explicit correlations compute intermediate species, based upon results. For largest PFAS, including perfluorooctanoic acid (PFOA) heptafluoropropylene oxide dimer (GenX), coupled-cluster local is used. sequence homodesmotic reactions proposed by CBH determined automatically new open-source code, AutoCBH. results first reported majority species. convergence analysis global uncertainty quantification confirm that at 0 K should be accurate within ±5 kJ/mol. This approach not limited but can applied many chemical systems.

Язык: Английский

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Fate of perfluoroalkyl and polyfluoroalkyl substances (PFAS) through two full‐scale wastewater sludge incinerators

Water Environment Research, Год журнала: 2024, Номер 96(3)

Опубликована: Март 1, 2024

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are an emerging issue in wastewater treatment. High-temperature thermal processes, incineration being time-tested, offer the opportunity to destroy change composition of PFAS. The fate PFAS has been documented through sludge incinerators, including a multiple hearth furnace (MHF) fluidized bed (FBF). dewatered feedstock averaged 247- 1280-μmol targeted per sample run MHF FBF feed, respectively. Stack emissions (reportable for all from only) 5% that value with shorter alkyl chain compounds comprising majority Wet scrubber water streams accumulated nonpolar fluorinated organics exhaust average 0.740- 0.114-mol F- run, FBF, Simple alkane measured at stack represented 0.5%-4.5% total estimated facility greenhouse gas emissions. PRACTITIONER POINTS: emitted six short stack, which were compared did not consistently emit reportable but contamination complicated assessment. Five percent molar load was reported stack. wet exhaust. Ultra-short volatile

Язык: Английский

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Catalytic Degradation of Hexafluoropropylene Oxide Trimeric Acid during the Hydrothermal Regeneration of Spent Activated Carbon

ACS ES&T Engineering, Год журнала: 2024, Номер 4(6), С. 1391 - 1400

Опубликована: Май 29, 2024

Regeneration of granular activated carbon (GAC) after adsorption perfluoroalkyl and polyfluoroalkyl substances is an emerging challenge. This study reports a successful regeneration spent GAC with hexafluoropropylene oxide trimer acid (HFPO–TA) at 120 °C. For the first time, we observed that significantly catalyzed degradation defluorination adsorbed HFPO–TA. The new catalytic mechanism HFPO–TA on was proposed. Reaction intermediates' analysis confirmed ether group near carboxyl split into dimer (HFPO–DA) trifluoroacetic (TFA). Subsequently, HFPO–DA further broken down to produce PFPrA TFA. These intermediates were detected only when not found dissolved in water without GAC. Bond dissociation energy calculations revealed close carboxylic had smaller more susceptible breakage compared decarboxylation reaction gas-phase products contained significant amounts 1H-substituted HFPO–DA, indicating Furthermore, density functional theory indicated site carried positive charge GAC, facilitating through nucleophilic reaction. Finally, efficiency remained 81% fifth adsorption–degradation cycle. offers novel cost-effective strategy for degradative HFPO–TA-adsorbed

Язык: Английский

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