Removal of per- and polyfluoroalkyl substances from water by plasma treatment: Insights into structural effects and underlying mechanisms

Water Research, Journal Year: 2024, Volume and Issue: 253, P. 121316 - 121316

Published: Feb. 14, 2024

Language: Английский

---

Electrochemical Reduction of Perfluorooctanoic Acid (PFOA): An Experimental and Theoretical Approach

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(15), P. 10687 - 10698

Published: April 5, 2024

Perfluorooctanoic acid (PFOA) is an artificial chemical of global concern due to its high environmental persistence and potential human health risk. Electrochemical methods are promising technologies for water treatment because they efficient, cheap, scalable. The electrochemical reduction PFOA one the current methodologies. This process leads defluorination carbon chain hydrogenated products. Here, we describe a mechanistic study in gold electrodes. By using linear sweep voltammetry (LSV), E0′ −1.80 V vs Ag/AgCl was estimated. Using scan rate diagnosis, determined electron-transfer coefficient (αexp) 0.37, corresponding concerted mechanism. strong adsorption into surface confirmed by Langmuir-like isotherm absence (KA = 1.89 × 1012 cm3 mol–1) presence negative 3.94 107 mol–1, at −1.40 Ag/AgCl). Based on Marcus–Hush's theory, calculations show solvent reorganization energy (λ0) 0.9 eV, suggesting large electrostatic repulsion between perfluorinated water. estimated free transition state electron transfer (ΔG‡ 2.42 eV) suggests that it thermodynamically reaction-limiting step. 19F – 1H NMR, UV–vis, mass spectrometry studies confirm displacement fluorine atoms hydrogen. Density functional theory (DFT) also support mechanism reductive PFOA, agreement with experimental values.

Language: Английский

---

Unveiling the Contribution of Hydrogen Radicals to Per- and Polyfluoroalkyl Substances (PFASs) Defluorination: Applicability and Degradation Mechanisms

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 12, 2025

At present, the defluorination of per- and polyfluoroalkyl substances (PFASs), including perfluoroether compounds as substitutes perfluorooctanoic acid (PFOA) perfluorooctanesulfonate, is limited by effective active species produced during oxidation-reduction process. The contribution hydrogen radical (•H) a companion substance in photoreduction electrocatalytic degradation PFASs has been neglected. Herein, we demonstrate that perfluorocarboxylic acids such PFOA hexafluoropropylene oxide dimer (GenX) underwent near-complete photodegradation continuously generating •H through perfluoroalkyl activation water under UV irradiation without any reagents catalysts. Importantly, initial dissolved oxygen, H+, impurities surface scarcely inhibited PFASs. difference mechanism between GenX action was elucidated combining theoretical calculations with targeted nontargeted analysis methods. investigation different indicates were not easily photodegraded via reduction compared other compounds, whereas polyfluorinated which some F atoms replaced Cl more prone to elimination. However, UV/•H system ineffective against perfluorosulfonic acids. This study provides an unprecedented perspective for further development removal technology design alternative are easy eliminate.

Language: Английский

---

Circulating microdroplet-driven self-Fenton for micropollutant elimination: the overlook of ligand-to-metal charge transfer and chloride radical

Applied Catalysis B Environment and Energy, Journal Year: 2025, Volume and Issue: unknown, P. 125214 - 125214

Published: Feb. 1, 2025

Language: Английский

---

Target and nontarget analysis of per- and polyfluoroalkyl substances in surface water, groundwater and sediments of three typical fluorochemical industrial parks in China

Journal of Hazardous Materials, Journal Year: 2023, Volume and Issue: 460, P. 132411 - 132411

Published: Aug. 29, 2023

Language: Английский

---

Fluoropolymers as Unique and Irreplaceable Materials: Challenges and Future Trends in These Specific Per or Poly-Fluoroalkyl Substances

Molecules, Journal Year: 2023, Volume and Issue: 28(22), P. 7564 - 7564

Published: Nov. 13, 2023

In contrast to some low-molar-mass per- and polyfluoroalkyl substances (PFASs), which are well established be toxic, persistent, bioaccumulative, mobile, fluoropolymers (FPs) water-insoluble, safe, bioinert, durable. These niche high-performance polymers fulfil the 13 polymer-of-low-concern (PLC) criteria in their recommended conditions of use. addition, more recent innovations (e.g., use non-fluorinated surfactants aqueous radical (co)polymerization fluoroalkenes) from industrial manufacturers FPs highlighted. This review also aims show how these specialty endowed with outstanding properties essential (even irreplaceable, since hydrocarbon polymer alternatives used similar fail) for our daily life (electronics, energy, optics, internet things, transportation, etc.) constitute a special family separate other “conventional” C1–C10 PFASs found everywhere on Earth its oceans. Furthermore, information reports recycling unzipping depolymerization polytetrafluoroethylene, PTFE, into TFE), end-of-life FPs, risk assessment, circular economy, regulations. Various studies devoted environments involving though they present volume (with yearly production 330,300 t) compared all plastics 460 million t). Complementary reviews PFASs, lack such above data, this presents both fundamental applied strategies as evidenced by major FP producers.

Language: Английский

---

Nontarget Screening and Fate of Emerging Per- and Polyfluoroalkyl Substances in Wastewater Treatment Plants in Tianjin, China

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(48), P. 20127 - 20137

Published: Oct. 6, 2023

Wastewater treatment plants (WWTPs) are typical point sources of per- and polyfluoroalkyl substances (PFAS) released into the environment. The suspect nontarget screening based on gas chromatography or liquid chromatography-high resolution mass spectrometry were performed atmosphere, wastewater, sludge samples collected from two WWTPs in Tianjin to discover emerging PFAS their fate this study. A total 40 (14 neutral 26 ionic) 64 identified atmosphere wastewater/sludge, respectively, among which 5 short-chain perfluoroalkyl sulfonamide derivatives, 4 ionic PFAS, 15 aqueous film-forming foam-related cationic zwitterionic have rarely never been reported China. Active air sampling is more conducive enrichment while passive inclined leave out some ultrashort-chain unstable transformation intermediates. Moreover, most precursors intermediates could be enriched at night, associated with aerosols high water content particles enter easily during day. Although not eliminated efficiently conventional units, deep bed filtration advanced oxidation processes partly remove precursors.

Language: Английский

---

Chlorine oxide radical: An emerging free radical for denitrification and pollutant degradation

Journal of environmental chemical engineering, Journal Year: 2024, Volume and Issue: 12(3), P. 112630 - 112630

Published: March 28, 2024

Language: Английский

---

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

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown

Published: April 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

Language: Английский

---

Promoting SO₄^·– and ^·OH Generation from Sulfate Solution toward Efficient Electrochemical Oxidation of Organic Contaminants at a B/N-Doped Diamond Flow-Through Electrode

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 22, 2025

Electrochemical oxidation via in situ-generated reactive oxygen species (ROS) is effective for the mineralization of refractory organic pollutants. However, performance usually limited by low yield and utilization efficiency ROS. Herein, a B/N-doped diamond (BND) flow-through electrode with enhanced SO4·–/·OH generation was designed electrochemical pollutants sulfate solution. Both its yields SO4·– selectivity were improved regulating B/N doping, production facilitated mode. BND showed fast PFOA kinetic constants 2.56–4.58 h–1 at current densities 2.0–5.0 mA cm–2. Its energy consumption 2.15–6.46 kWh m–3, which lower than those state-of-the-art electrodes under similar conditions. The anode also efficient treating fluorine wastewater coking wastewater. superior contributed utilization, as well high selectivity.

Language: Английский

---