Photochemistry of acenaphthene at a silica gel/air interface

Reyes, Celso; Sigman, Michael E.; Arce, Rafael; Barbas, John T.; Dabestani, Reza

doi:10.1016/s1010-6030(97)00290-6

Cited by 33 publications

(32 citation statements)

References 16 publications

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“…Thereinto, amorphous silica (AS) in soils is assumed to play a major role in Si availability and cycling because it is more soluble than crystalline minerals . A significant portion of total particulate matters in the atmosphere is originally from soils, and thus AS is always found in the constituents of aerosol particulates . It was reported that Si–O • or Si • radicals on AS surfaces could form after light irradiation due to the disordered structure of AS, which could react with adsorbed H 2 O 2 , H 2 O, and O 2 to yield reactive oxygen species (ROS) such as • OH, O 2 •– , etc .…”

Section: Introductionmentioning

confidence: 99%

Persistent Free Radicals from Low-Molecular-Weight Organic Compounds Enhance Cross-Coupling Reactions and Toxicity of Anthracene on Amorphous Silica Surfaces under Light

Sun

Wang

Liu

et al. 2021

Environ. Sci. Technol.

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Polycyclic aromatic hydrocarbon (PAH) contamination has raised great environmental concerns, while the effects of low-molecular-weight organic compounds (LMWOCs) on PAH photodegradation at amorphous silica (AS)/air interfaces have been largely ignored. In this study, the phototransformation of anthracene (ANT) at amorphous silica (AS)/air interfaces was investigated with the addition of LMWOCs. ANT removal was attributed to •OH attacking and the energy transfer process via 3ANT*. Light irradiation induced the fractured SiO• or Si• generation on AS surfaces, which could react with absorbed H2O and O2 to generate •OH and further yield a series of hydroxylated products of ANT. The presence of citric acid and oxalic acid improved •OH generation and enhanced ANT removal by 1.0- and 2.2-fold, respectively. For comparison, the presence of catechol and hydroquinone significantly decreased ANT removal and produced coupling products. The results of density functional theory calculations suggest that persistent free radicals (PFRs) on AS surfaces from catechol or hydroquinone after •OH attacking prefer to cross-couple with ANT via C–C bonding rather than self-couple. Dianthrone and cross-coupling products might possess higher ecotoxicity, while hydroxylated products were less ecotoxic than their parent compounds based on Ecological Structure Activity Relationships (ECOSAR) estimation. The results of this study revealed the potential ecotoxicity of PAH-adsorbed particulates coexisting with LMWOCs and also provided a new insight into PAH transformation through PFR pathways.

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Section: Introductionmentioning

confidence: 99%

Persistent Free Radicals from Low-Molecular-Weight Organic Compounds Enhance Cross-Coupling Reactions and Toxicity of Anthracene on Amorphous Silica Surfaces under Light

Sun

Wang

Liu

et al. 2021

Environ. Sci. Technol.

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“…8, as the particulate matter before, during and after the fog has very large OPAC/PAH ratios. The gas phase has a significantly lower OPAC content, indicating that the oxidation of acenaphthene is either facilitated by the air-particulate interface 64 or that the (gas-phase) oxidation products associate predominantly with particles. Both effects are likely to happen simultaneously as the surface-enhanced oxidation of acenaphthene has been described before 64 and the vapor pressure of the monitored oxidation products 65,66 (acenaphthenequinone, 1-acenaphthenone, 1-acenaphthenol and 1,8-naphthalic acid anhydride) is at least two orders of magnitude lower than that of acenaphthene.…”

Section: Resultsmentioning

confidence: 99%

“…The gas phase has a significantly lower OPAC content, indicating that the oxidation of acenaphthene is either facilitated by the air-particulate interface 64 or that the (gas-phase) oxidation products associate predominantly with particles. Both effects are likely to happen simultaneously as the surface-enhanced oxidation of acenaphthene has been described before 64 and the vapor pressure of the monitored oxidation products 65,66 (acenaphthenequinone, 1-acenaphthenone, 1-acenaphthenol and 1,8-naphthalic acid anhydride) is at least two orders of magnitude lower than that of acenaphthene. The presence of fog water does not enhance the degradation of acenaphthene significantly, as its degradation rate is already high; however, the dissolution of the oxidation products of acenaphthene from the PM 2.5 to the fog water can be clearly seen in Fig.…”

Section: Resultsmentioning

confidence: 99%

Processing of atmospheric polycyclic aromatic hydrocarbons by fog in an urban environment

et al. 2012

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Polycyclic aromatic hydrocarbons (PAH) are ubiquitous pollutants in the atmosphere, predominantly known for their toxicity. Although there has been substantial work on the atmospheric degradation of PAH, little is known about how the presence of atmospheric droplets (e.g., a fog cloud) affects the fate of PAH. In order to assess the processing of PAH and their corresponding oxidation products during a fog event, two field-sampling campaigns in Fresno, CA and Davis, CA were conducted. The simultaneous evaluation of concentrations of the PAH and oxygenated polycyclic aromatic compounds (OPAC) in the gas phase, particulate matter and fog water droplets before, during and after fog allows for the characterization of transformative and transport processes in a fog cloud. By tracking the ratio of OPAC to PAH in the individual atmospheric phases, two major polycyclic aromatic compounds-processing pathways can be identified: (i) the dissolution of OPAC from particulate matter and (ii) the uptake and oxidation of PAH in the fog water droplets. Wet deposition steadily decreases the pollutant concentration in the fog cloud droplets during a fog event; however, uptake and concentration via evaporative water loss upon the dissipation of a fog cloud cause an increase in the atmospheric pollutant concentration.

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“…In other laboratory experiments [26][27][28], it was reported that 1,8-NA could be formed by the oxidation of several PAHs, such as acenaphthylene, acenaphthene and even those with more than three rings like benz [a]anthracene. In addition, Kamens et al [14] conducted outdoor chamber experiments where diluted wood smoke was exposed to midday natural sunlight and found that particle-associated 1,8-NA increased in concentrations with time in the presence of the sunlight (and low photochemical O 3 accumulation, i.e.…”

Section: Size Distribution Of Pahs In Urban Atmospheric Particlesmentioning

confidence: 99%

Study on the size-segregated distribution of 37 species of polycyclic aromatic hydrocarbons in urban atmospheric fine particles of Japan

Wang

Kobayashi

Zhou

et al. 2014

WIT Transactions on Ecology and the Environment

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The size-segregated distribution and seasonal concentrations of polycyclic aromatic hydrocarbons (PAHs) in urban suspended particulate matter (SPM) at the Japan national route 463 in the urban of Saitama city, Japan were investigated using an Andersen high-volume air sampler. Air sampling was carried out from June 2013 to January 2014. 37 species of toxic PAHs such as benzo [j] [a,l]pyrene were measured. It was found that the average concentration of 37 species of particulate PAHs including methyl-PAHs, benzothiophenes and oxy-PAHs from atmospheric oxidation of PAHs collected in the urban of Saitama city was 3.42 to 6.51 ng/m 3 during 2013 sampling campaign periods. 1,8-naphthalic anhydride (1,8-NA) showed the highest concentration among 37 species of PAHs. The concentrations of high molecular PAHs, which were found in all seasons, followed different size distribution, especially with the highest peak in fine particle sizes around 1.1 μm. The concentrations of low-molecular PAHs were not much different with particle sizes. The toxicity analysis indicated that the carcinogenic potency of particulate PAHs primarily existed in the particle size below 1.1 μm. 37 species of PAHs in urban atmospheric fine particles were not only derived from vehicle emission with long range transportation, but also produced by local other anthropogenic sources.

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Photochemistry of acenaphthene at a silica gel/air interface

Cited by 33 publications

References 16 publications

Persistent Free Radicals from Low-Molecular-Weight Organic Compounds Enhance Cross-Coupling Reactions and Toxicity of Anthracene on Amorphous Silica Surfaces under Light

Persistent Free Radicals from Low-Molecular-Weight Organic Compounds Enhance Cross-Coupling Reactions and Toxicity of Anthracene on Amorphous Silica Surfaces under Light

Processing of atmospheric polycyclic aromatic hydrocarbons by fog in an urban environment

Study on the size-segregated distribution of 37 species of polycyclic aromatic hydrocarbons in urban atmospheric fine particles of Japan

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