State-of-the-art review on photocatalysis for efficient wastewater treatment: Attractive approach in photocatalyst design and parameters affecting the photocatalytic degradation

Catalysis Communications, Год журнала: 2023, Номер 183, С. 106764 - 106764

Опубликована: Сен. 15, 2023

This review focuses on recently proposed photocatalyst designs for maximizing the efficiency of photogenerated charge carriers to improve photocatalytic performance photocatalysts. These include doping with metal and non-metal ions, surface grafting, noble deposition, dye sensitization, heterostructure fabrication. In addition, this thoroughly examines all prominent parameters that can influence degradation Furthermore, summarizes energy-band structures photocatalysts are suitable both O2 reduction oxidation H2O molecules generate reactive oxygen species. Lastly, we discuss future trends in development environmental applications.

Язык: Английский

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PFAS degradation by anodic electrooxidation: Influence of BDD electrode configuration and presence of dissolved organic matter

Chemical Engineering Journal, Год журнала: 2024, Номер 489, С. 151355 - 151355

Опубликована: Апрель 17, 2024

Язык: Английский

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Structural dependence of PFAS oxidation in a boron doped diamond-electrochemical system

Environmental Research, Год журнала: 2024, Номер 246, С. 118103 - 118103

Опубликована: Янв. 3, 2024

Driven by long-term persistence and adverse health impacts of legacy perfluorooctanoic acid (PFOA), production has shifted towards shorter chain analogs (C4, perfluorobutanoic (PFBA)) or fluorinated alternatives such as hexafluoropropylene oxide dimer (HFPO-DA, known GenX) 6:2 fluorotelomer carboxylic (6:2 FTCA). Yet, a thorough understanding treatment processes for these is limited. Herein, we conducted comprehensive study using an electrochemical approach with boron doped diamond anode in Na2SO4 electrolyte the remediation PFOA common alternatives, i.e., PFBA, GenX, FTCA. The degradability, fluorine recovery, transformation pathway, contributions from electro-synthesized radicals were investigated. results indicated significance length structure, chains being harder to break down (PFBA (65.6 ± 5.0%) < GenX (84.9 3.3%) (97.9 0.1%) FTCA (99.4 0.0%) within 120 min electrolysis). same by-products observed during oxidation both low high concentrations parent PFAS (2 20 mg L−1), indicating that fundamental mechanism degradation remained consistent. Nevertheless, ratio concentration varied which primarily arises more rapid decomposition at lower dosages. For all experiments, main was initiated direct electron transfer surface. Sulfate radical (SO4•−) also contributed PFAS, while hydroxyl (•OH) only played role Total recovery 96.5%, 94.0%, 76.4% 240 min. complex pathway could explain its recovery. Detailed pathways each proposed through identifying generated intermediates assessed 19F Nuclear Magnetic Resonance (NMR) spectroscopy.

Язык: Английский

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A mini-review on advanced reduction processes for per- and polyfluoroalkyl substances remediation: current status and future prospects

Current Opinion in Chemical Engineering, Год журнала: 2024, Номер 44, С. 101018 - 101018

Опубликована: Апрель 3, 2024

Advanced reduction processes (ARPs) have emerged as promising techniques for destruction of persistent per- and polyfluoroalkyl substances (PFAS) due to the formation highly reductive hydrated electrons (eaq−). The present study provides a critical review progress prospects field over past three five years categorizing topics into main sections: i) state art ARPs, comparing promise mechanisms methods such photochemical, ionizing irradiation, plasma, sonolysis, electroreduction, zero-valent iron; ii) integration ARPs with physical-separation methods, oxidation processes, their role in regeneration/management PFAS-laden media; iii) challenges/innovations real-world application ARPs. Three primary future research directions are also proposed alignment current upcoming focuses.

Язык: Английский

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Managing PFAS exhausted Ion-exchange resins through effective regeneration/electrochemical process

Water Research, Год журнала: 2024, Номер 255, С. 121529 - 121529

Опубликована: Март 26, 2024

This study proposes an integrated approach that combines ion-exchange (IX) and electrochemical technologies to tackle problems associated with PFAS contamination. Our investigation centers on evaluating the recovery efficiency of IX/electrochemical systems in presence five different salts, spanning dosages from 0.1% 8%. The outcomes reveal a slight superiority for NaCl within regeneration system, sulfate bicarbonate also showing comparable efficacy. Notably, introduction chloride ion (Cl−) into system results substantial generation undesirable chlorate (ClO3−) perchlorate (ClO4−) by-products, accounting ∼18% ∼81% consumed Cl−, respectively. Several agents, including H2O2, KI, Na2S2O3, exhibited effective mitigation ClO3− ClO4− formation. However, only H2O2 demonstrated favorable influence degradation defluorination PFOA. addition 0.8 M resulted near-complete removal ClO4−, accompanied by 1.3 2.2-fold enhancements PFOA, Furthermore, comparative analysis salts reveals Cl− OH− ions exhibit slower performance, possibly due competitive interactions PFOA anode's reactive sites. In contrast, consistently demonstrate robust decomposition efficiencies. Despite notable enhancement IX efficacy facilitated methanol, particularly PFAS-specific resins, this comes at cost reduced all PFAS. average decay rate ratio 50% compared its absence, falls range 0.11-0.39. conclusion, use 1% Na2SO4 salt stands out as option process. choice not eliminates need introduce additional chemical (e.g., H2O2) wastewater stream, but ensures both satisfactory process through treatment.

Язык: Английский

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Per-and polyfluoroalkyl degradation in a hybrid dielectric barrier discharge plasma and electrooxidation system through involving more reactive species by air and water circulation

Journal of Hazardous Materials, Год журнала: 2025, Номер 488, С. 137287 - 137287

Опубликована: Янв. 21, 2025

Язык: Английский

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Photo-oxidative/reductive decomposition of perfluorooctanoic acid (PFOA) and its common alternatives: Mechanism and kinetic modeling

Journal of Water Process Engineering, Год журнала: 2024, Номер 61, С. 105332 - 105332

Опубликована: Апрель 18, 2024

Per- and poly-fluoroalkyl substances (PFAS) are a group of diverse anthropogenic chemicals that global concern. This study explored degradation perfluorooctanoic acid (PFOA), its common alternatives, perfluorobutanoic (PFBA) hexafluoropropylene oxide dimer (HFPO-DA or GenX) through photochemical processes employing sulfite persulfate mediators. Specific objectives were to i) assess key operational parameters their interactions, ii) determine the roles direct photolysis, generated active species, UV wavelengths, iii) explore impacts copresent organic inorganic constituents, iv) develop kinetic model for sulfite-mediated optical intrinsic rates studied PFAS with hydrated electron (eaq−). Photochemical experiments conducted in well-controlled collimated beam setups, facilitating fluence-based study. In both sulfite- persulfate-mediated systems, solution pH is most significant factor, followed by mediator concentration. The Φ254 nm Φ185 0.104 ± 0.007 1.38 0.11 mol/einstein, highlighting synergistic impact introducing 185 process. Scavengers water matrices influence eaq− SO4•– dominating respectively. highlights potential role O2•– GenX decomposition elucidates intermediates evolution mechanisms, where lead distinct CO bond breakage GenX. process exhibits slower kinetics, resulting higher lower defluorination efficiency. Kinetic modeling reveals rate constants PFOA, PFBA, as (8.34 0.08) × 107, (5.85 0.07) (1.70 0.10) 107 M−1 s−1,

Язык: Английский

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Effects of functional groups of polyfluoroalkyl substances on their removal by nanofiltration

Water Research X, Год журнала: 2024, Номер 24, С. 100233 - 100233

Опубликована: Июль 3, 2024

Determining the reliability of nanofiltration (NF) membranes for removal contaminants emerging concern, including polyfluoroalkyl substances (PFASs), pharmaceuticals, and personal care products (PPCPs), is important ensuring drinking water safety. This study aimed to clarify factors that influence nine major PFASs during submerged NF treatment via extrapolation based on PPCP removal. The rejection in ultra-filtered dam by a polypiperazine-amide (NF270) membrane increased from 71 % 94 at low permeate flux 5 L/m

Язык: Английский

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Ion exchange and advanced oxidation/reduction processes for per- and polyfluoroalkyl substances treatment: a mini-review

Current Opinion in Chemical Engineering, Год журнала: 2023, Номер 42, С. 100953 - 100953

Опубликована: Сен. 14, 2023

Язык: Английский

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PFAS in Landfill Leachate: Practical Considerations for Treatment and Characterization

Journal of Hazardous Materials, Год журнала: 2024, Номер unknown, С. 136685 - 136685

Опубликована: Ноя. 1, 2024

Язык: Английский

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