Temperature effect on photolysis decomposing of perfluorooctanoic acid

Zhang, Tiliang; Pan, Gang; Zhou, Qin

doi:10.1016/j.jes.2015.05.008

Cited by 26 publications

(6 citation statements)

References 50 publications

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“…Interestingly, in S1am all three compounds show significant correlation (ρ = 0.44, 0.52, 0.45, and 0.33 respectively; p < 0.05) with water temperature as well, which may be explained by the fact that quantum yield, and thus photolysis rate increases with water temperature. 64 The high correlation of hydrochlorothiazide attenuation with solar radiation (Figure 3) makes it a potential future candidate for tracing intrinsic photolytical processes in contaminated rivers.…”

Section: Environmental Science and Technologymentioning

confidence: 99%

Spatial and Temporal Variability in Attenuation of Polar Organic Micropollutants in an Urban Lowland Stream

Jaeger

Posselt

Betterle

et al. 2019

Environ. Sci. Technol.

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Contamination of rivers by trace organic compounds (TrOCs) poses a risk for aquatic ecosystems and drinking water quality. Spatially- and temporally varying environmental conditions are expected to play a major role in controlling in-stream attenuation of TrOCs. This variability is rarely captured by in situ studies of TrOC attenuation. Instead, snap-shots or time-weighted average conditions and corresponding attenuation rates are reported. The present work sought to investigate this variability and factors controlling it by analysis of 24 TrOCs over a 4.7 km reach of the River Erpe (Berlin, Germany). The factors investigated included sunlight and water temperature as well as the presence of macrophytes. Attenuation rate constants in 48 consecutive hourly water parcels were tracked along two contiguous river sections of different characteristics. Section 1 was less shaded and more densely covered with submerged macrophytes compared to section 2. The sampling campaign was repeated after macrophyte removal from section 1. The findings show, that section 1 generally provided more favorable conditions for both photo- and biodegradation. Macrophyte removal enhanced photolysis of some compounds (e.g., hydrochlorothiazide and diclofenac) while reducing the biodegradation of metoprolol. The transformation products metoprolol acid and valsartan acid were formed along the reach under all conditions.

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Section: Environmental Science and Technologymentioning

confidence: 99%

Spatial and Temporal Variability in Attenuation of Polar Organic Micropollutants in an Urban Lowland Stream

Jaeger

Posselt

Betterle

et al. 2019

Environ. Sci. Technol.

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“…Consequently, many unregulated PFASs could have indirect impacts by producing more recalcitrant products during chemical transformations such as PFOA. , Chemical transformation from one PFAS compound to another in the context of remediation is also an active area of investigation, and several of these mechanisms remain unexplored to date . Currently, AOTs including UV photolysis, − surface- and or metal-mediated photocatalysis, − sonolysis, − electrochemical decomposition, − and persulfate oxidation ,− have shown promise to degrade PFOA and other PFAS compounds, but so far, many have shown only lab-scale applicability.…”

Section: Introductionmentioning

confidence: 99%

1,2-Fluorine Radical Rearrangements: Isomerization Events in Perfluorinated Radicals

Hoomissen

Vyas

2017

J. Phys. Chem. A

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Devising effective degradation technologies for perfluoroalkyl substances (PFASs) is an active area of research, where the molecular mechanisms involving both oxidative and reductive pathways are still elusive. One commonly neglected pathway in PFAS degradation is fluorine atom migration in perfluoroalkyl radicals, which was largely assumed to be implausible because of the high C-F bond strength. Using density functional theory calculations, it was demonstrated that 1,2-F atom migrations are thermodynamically favored when the fluorine atom migrated from a less branched carbon center to a more branched carbon center. Activation barriers for these rearrangements were within 19-29 kcal/mol, which are possible to easily overcome at elevated temperatures or in photochemically activated species in the gas or aqueous phase. It was also found that the activation barriers for the 1,2-F atom migration are lowered as much as by 10 kcal/mol when common oxidative degradation products such as HF assisted the rearrangements or if the resulting radical center was stabilized by vicinal π-bonds. Natural bond orbital analyses showed that fluorine moves as a radical in a noncharge-separated state. These findings add an important reaction to the existing knowledge of mechanisms for PFAS degradation and highlights the fact that 1,2-F atom shifts may be a small channel for isomerization of these compounds, but upon availability of mineralization products, this isomerization process could become more prominent.

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“…La descomposición de los contaminantes es más eficiente en cortos tiempos exposición, cuando la temperatura incrementa cerca de 60 °C con ayuda de luz ultravioleta (Zhang et al, 2016).…”

Section: Temperaturaunclassified

Tecnologías para el tratamiento de aguas con radiación solar para el desarrollo sustentable: Una Revisión

Rascón

Huaman

Ángeles

et al. 2021

Rev. de investig. agroproducción sustentable

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La falta de tecnologías económicas y eficientes para el tratamiento de aguas es un problema global. Muchos investigadores buscan nuevas alternativas para el tratamiento de aguas que, reemplacen a las tecnologías tradicionales como la cloración, la filtración o la ebullición. Algunas de las tecnologías alternativas, son los que utilizan la radiación solar como los destiladores solares, el fotofenton o la desinfección solar (SODIS). Son tecnologías más económicas a comparación con las tradicionales, al utilizar la radiación solar como energía renovable, y por lo tanto el costo disminuye. Sin embargo, mediante estas tecnologías, no se pueden tratar grandes volúmenes de agua, como es el caso del SODIS que pueden tratar eficiente mente bajos volúmenes de agua mediante el uso botellas de politereftalato de etileno (PET). En el intento de mejorar las tecnologías basados en radiación solar se han creado algunas como las bolsas SODIS o los colectores solares con espejos parabólicos, también llamados concentradores parabólicos compuestos (CPC). Aun así, también presentan una serie de inconvenientes. En el caso de las bolsas SODIS, dan un mal olor al agua tratada, mientras que, en el caso de los CPC el costo de su implementación es más elevado. Como una alternativa económica a todo esto, surgió la fotocatálisis que usa normalmente el Óxido de Titanio (TiO<sub>2</sub>) como fotocatalizador. Con ello se reducen los tiempos de exposición mediante reacciones redox, lo que hace que métodos como el SODIS sean más eficientes.

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Temperature effect on photolysis decomposing of perfluorooctanoic acid

Cited by 26 publications

References 50 publications

Spatial and Temporal Variability in Attenuation of Polar Organic Micropollutants in an Urban Lowland Stream

Spatial and Temporal Variability in Attenuation of Polar Organic Micropollutants in an Urban Lowland Stream

1,2-Fluorine Radical Rearrangements: Isomerization Events in Perfluorinated Radicals

Tecnologías para el tratamiento de aguas con radiación solar para el desarrollo sustentable: Una Revisión

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