Merits and Limitations of Radical vs. Nonradical Pathways in Persulfate-Based Advanced Oxidation Processes

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(33), P. 12153 - 12179

Published: Aug. 3, 2023

Urbanization and industrialization have exerted significant adverse effects on water quality, resulting in a growing need for reliable eco-friendly treatment technologies. Persulfate (PS)-based advanced oxidation processes (AOPs) are emerging as viable technologies to treat challenging industrial wastewaters or remediate groundwater impacted by hazardous wastes. While the generated reactive species can degrade variety of priority organic contaminants through radical nonradical pathways, there is lack systematic in-depth comparison these pathways practical implementation different scenarios. Our comparative analysis reaction rate constants vs. indicates that radical-based AOPs may achieve high removal efficiency with relatively short contact time. Nonradical feature advantages minimal matrix interference complex wastewater treatments. (e.g., singlet oxygen, high-valent metals, surface activated PS) preferentially react bearing electron-donating groups, allowing enhancement degradation known target contaminants. For byproduct formation, analytical limitations computational chemistry applications also considered. Finally, we propose holistically estimated electrical energy per order (EE/O) parameter show significantly higher requirements pathways. Overall, critical comparisons help prioritize basic research PS-based inform merits system-specific applications.

Language: Английский

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Activation of peroxymonosulfate via mediated electron transfer mechanism on single-atom Fe catalyst for effective organic pollutants removal

Applied Catalysis B Environment and Energy, Journal Year: 2021, Volume and Issue: 299, P. 120714 - 120714

Published: Sept. 14, 2021

Language: Английский

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Aqueous Iron(IV)–Oxo Complex: An Emerging Powerful Reactive Oxidant Formed by Iron(II)-Based Advanced Oxidation Processes for Oxidative Water Treatment

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(3), P. 1492 - 1509

Published: Jan. 10, 2022

High-valent iron(IV)–oxo complexes are of great significance as reactive intermediates implicated in diverse chemical and biological systems. The aqueous complex (FeaqIVO2+) is the simplest but one most powerful ferryl ion species, which possesses a high-spin state, high reduction potential, long lifetime. It has been well documented that FeaqIVO2+ reacts with organic compounds through various pathways (hydrogen-atom, hydride, oxygen-atom, electron transfer electrophilic addition) at moderate reaction rates show selective reactivity toward inorganic ions prevailing natural water, single out superior candidate for oxidative water treatment. This review provides state-of-the-art knowledge on properties oxidation mechanism kinetics FeaqIVO2+, special attention to similarities differences two representative free radicals (hydroxyl radical sulfate radical). Moreover, prospective role Feaq2+ activation-initiated advanced processes (AOPs) intensively investigated over past 20 years, significantly challenged conventional recognition dominated these AOPs. latest progress identifying contribution Feaq2+-based AOPs thereby reviewed, highlighting controversies nature oxidants formed several activated peroxide oxyacid processes. Finally, future perspectives advancing evaluation from an engineering viewpoint proposed.

Language: Английский

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Activation of peroxymonosulfate by single atom Co-N-C catalysts for high-efficient removal of chloroquine phosphate via non-radical pathways: Electron-transfer mechanism

Chemical Engineering Journal, Journal Year: 2021, Volume and Issue: 429, P. 132245 - 132245

Published: Sept. 3, 2021

Language: Английский

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Insights into the oxidation of organic contaminants by Co(II) activated peracetic acid: The overlooked role of high-valent cobalt-oxo species

Water Research, Journal Year: 2021, Volume and Issue: 201, P. 117313 - 117313

Published: May 31, 2021

Language: Английский

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Novel Nonradical Oxidation of Sulfonamide Antibiotics with Co(II)-Doped g-C₃N₄-Activated Peracetic Acid: Role of High-Valent Cobalt–Oxo Species

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 55(18), P. 12640 - 12651

Published: Aug. 31, 2021

Herein, we report that Co(II)-doped g-C3N4 can efficiently trigger peracetic acid (PAA) oxidation of various sulfonamides (SAs) in a wide pH range. Quite different from the traditional radical-generating or typical nonradical-involved (i.e., singlet oxygenation and mediated electron transfer) catalytic systems, PAA activation follows novel nonradical pathway with unprecedented high-valent cobalt–oxo species [Co(IV)] as dominant reactive species. Our experiments density functional theory calculations indicate Co atom fixated into nitrogen pots serves main active site, enabling dissociation adsorbed conversion coordinated Co(II) to Co(IV) via unique two-electron transfer mechanism. Considering be highly electrophilic nature, substituents five-membered six-membered heterocyclic moieties) on SAs could affect their nucleophilicity, thus leading differences degradation efficiency transformation pathway. Also, benefiting selective Co(IV), established oxidative system exhibits excellent anti-interference capacity achieves satisfactory decontamination performance under actual water conditions. This study provides new approach degrade by activating heterogeneous cobalt-complexed catalysts.

Language: Английский

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Fe, N-doped carbonaceous catalyst activating periodate for micropollutant removal: Significant role of electron transfer

Applied Catalysis B Environment and Energy, Journal Year: 2021, Volume and Issue: 303, P. 120880 - 120880

Published: Nov. 1, 2021

Language: Английский

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Oxygen doping of cobalt-single-atom coordination enhances peroxymonosulfate activation and high-valent cobalt–oxo species formation

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(16)

Published: April 11, 2023

The high-valent cobalt-oxo species (Co(IV)=O) is being increasingly investigated for water purification because of its high redox potential, long half-life, and antiinterference properties. However, generation Co(IV)=O inefficient unsustainable. Here, a cobalt-single-atom catalyst with N/O dual coordination was synthesized by O-doping engineering. O-doped (Co-OCN) greatly activated peroxymonosulfate (PMS) achieved pollutant degradation kinetic constant 73.12 min-1 g-2, which 4.9 times higher than that Co-CN (catalyst without O-doping) those most reported single-atom catalytic PMS systems. Co-OCN/PMS realized dominant oxidation pollutants increasing the steady-state concentration (1.03 × 10-10 M) 5.9 compared Co-CN/PMS. A competitive kinetics calculation showed contribution to micropollutant 97.5% during process. Density functional theory calculations influenced charge density (increased Bader transfer from 0.68 0.85 e), optimized electron distribution Co center d-band -1.14 -1.06 eV), enhanced adsorption energy -2.46 -3.03 eV, lowered barrier key reaction intermediate (*O*H2O) formation 1.12 0.98 eV. Co-OCN fabricated on carbon felt flow-through device, continuous efficient removal micropollutants (degradation efficiency >85% after 36 h operation). This study provides new protocol activation elimination through heteroatom-doping metal-oxo purification.

Language: Английский

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Sulfide-modified zero-valent iron activated periodate for sulfadiazine removal: Performance and dominant routine of reactive species production

Water Research, Journal Year: 2022, Volume and Issue: 220, P. 118676 - 118676

Published: May 26, 2022

Language: Английский

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Degradation of Organic Contaminants in the Fe(II)/Peroxymonosulfate Process under Acidic Conditions: The Overlooked Rapid Oxidation Stage

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 55(22), P. 15390 - 15399

Published: Nov. 3, 2021

The iron(II)-activated peroxymonosulfate [Fe(II)/PMS] process is effective in degrading organic contaminants with a rapid oxidation stage followed by slow one. Nevertheless, prior studies have greatly underestimated the degradation rates of and ignored differences kinetics mechanism these two stages. In this work, we investigated mechanisms under acidic conditions combining stopped-flow spectrophotometric method batch experiments. were rapidly oxidized rate constants 0.18–2.9 s–1 stage. Meanwhile, both Fe(IV) SO4•– active oxidants contributed differently to different Additionally, presence Cl– promoted phenol estradiol but effects Br– humic acid on differed from those contrast, was amounts generated small This work updates fundamental understanding process.

Language: Английский

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