Studies on Photochemical Reactions of Air Pollutants. XIV. Photooxidation of Sulfur Dioxide in Air by Various Air Pollutants

Nojima, Kazuhiro; Yamaashi, Y.

doi:10.1248/cpb.52.335

Cited by 3 publications

(4 citation statements)

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“…Photodissociation to produce SO + O is not possible in the troposphere because it requires wavelengths (∼217 nm) beyond the tropospheric cutoff (290 nm). Photo-oxidation processes were considered, − namely disproportionation and spin-forbidden reaction with O 2 , ,− but experiments showed that upon exposure to sunlight, SO 2 in air is oxidized to SO 3 only in the presence of pollutants . Reaction with hydrocarbons RH was shown to produce R and HOSO radicals through H-transfer. , There is now consensus that the reactive entity in the photochemistry of pure sulfur dioxide is the triplet state molecule 3 SO 2 . , The lowest triplet state ( 3 B 1 ) can be reached by direct absorption of light or by intersystem crossing from the lowest excited singlet states ( l A 2 and 1 B 1 ) in the first allowed absorption band, which extends from 240 to 330 nm, and the excited states decay into the ground state through radiative or nonradiative processes (eqs –).…”

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“…Photo-oxidation processes were considered, 7−9 namely disproportionation and spin-forbidden reaction with O 2 , 7,10−12 but experiments showed that upon exposure to sunlight, SO 2 in air is oxidized to SO 3 only in the presence of pollutants. 13 Reaction with hydrocarbons RH was shown to produce R and HOSO radicals through H-transfer. 14,15 There is now consensus that the reactive entity in the photochemistry of pure sulfur dioxide is the triplet state molecule 3 SO 2 .…”

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Photochemistry of SO₂ at the Air–Water Interface: A Source of OH and HOSO Radicals

et al. 2018

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The photochemistry of sulfur dioxide in the near UV-vis energy range has been studied in aqueous environments. The combination of previously reported experimental measurements with accurate quantum chemical calculations achieved in this work reveals that the process represents an important source of OH radicals in the troposphere. It implicates the reaction of the lowest triplet excited state of SO with a water molecule. When the process occurs in the gas-phase, photochemical OH production is only significant under high humidity conditions and high SO concentrations as those measured in polluted urban areas. However, the OH production rate increases by several orders of magnitude when the process takes place at the surface of water droplets. The present study indicates therefore that the atmospheric importance of sulfur dioxide goes beyond its well-known role as acid rain and aerosol formation precursor.

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Photochemistry of SO₂ at the Air–Water Interface: A Source of OH and HOSO Radicals

et al. 2018

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“…Sulfur dioxide can also be converted to sulfuric acid by other routes. Sulfur dioxide that leaves the smokestack of the power plant can react with ultraviolet light in sunlight and other species in the air such as hydroxyl radicals, biacetyl, benzaldehyde, and nitrogen dioxide to produce sulfur trioxide, but whether the sulfur dioxide can be oxidized in sunlight without these species present is controversial , . The sulfur dioxide can react with liquid water adsorbed onto the ash surfaces to produce sulfurous acid.…”

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Classroom Illustrations of Acidic Air Pollution Using Nylon Fabric

et al. 2011

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seemed to be a fairly typical warm and muggy summer day in central Illinois, but something out of the ordinary arrived from the skies. In downtown Peoria by the riverfront, businesses were making money, factories were making products, and smoke billowed into the sky from the smokestack of one of the coal-burning power plants. When lunchtime rolled around, the employees from the local stores walked to the local restaurants to refuel for the rest of the afternoon. According to an article in the local paper, the "Peoria Journal Star" (1), the ladies working downtown noticed ash deposits and holes in their nylon stockings after returning from lunch. They concluded that the ash had attacked the fibers of the nylon stockings. Many ladies returned their stockings to the store where they had been purchased, but the same disintegration occurred as they walked back to work (1). When the employees returned to work, many of them reported having headaches and burning of the eyes. 1 The affected people were angered at the damage apparently caused by this ash, even though pollution regulations were weaker in those days. Accusations were made against the power plant, but a company representative denied the allegations by saying, "We haven't changed anything we are doing that would cause this phenomenon, but we will investigate to see if there is something that we aren't aware of that would have caused it" (1). The local news featured a company representative placing stockings under the smoke stack and no damage was observed (2). The company claimed that because of this, there was no way that the smoke could be blamed. Many people took this as fact. However, what happened next became part of the Bradley University Chemistry departmental lore. David Sweet, a student who was researching with Professor Tom Cummings in the Chemistry Department, believed that this demonstration was flawed. The ash that had fallen from the sky was fly ash, a byproduct of coal combustion flying up and out the power plant smokestack. It appeared to him that the fly ash falling from the smokestack had carried sulfur-containing oxyacids out of the exhaust plume down to earth. When the ash came in contact with the nylon stockings, the acids attacked the fabric.David Sweet was so infuriated by the power company's claims that he called both the company and a local TV station to complain. There was no success with the company, but a TV news reporter asked him for an interview. Sweet went to the lab to come up with a demonstration proving the company was wrong (2). He ran a sequence of experiments in which he passed sulfur dioxide from a small tank up a ceramic tube through nylon stockings in attempt to mimic the environmental conditions on the day the nylon damage occurred. The first experiment used a dry, room-temperature stocking, and as he passed the sulfur dioxide through it there was no damage. He then passed the sulfur dioxide

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“…Such characteristic results in the selectivity on the analysis of SDA. 4-NPH•HCl [14] was selected from many hydrazine derivatives because of its high solubility in methanol which also acts as a part of solvent to dissolve DAA in the reaction.…”

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confidence: 99%

Facile and Accurate Analysis of Sodium Dehydroacetate in Cosmetic Powders After Extraction by Na2CO3-Methanol-H2O and Derivatization with 4-Nitrophenylhydrazine∙HCl

et al. 2017

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Sodium dehydroacetate (SDA) was extracted from cosmetic powders using a Na 2 CO 3 -methanol-H 2 O system. After the extract was neutralized, the resulting dehydroacetic acid (DAA) reacted with 4-nitrophenylhydrazine•HCl (4-NPH•HCl) to give the corresponding hydrazone, which was determined by an HPLC-VIS (400 nm) system. Using 4-NPH•HCl in great excess was suitable for detecting the presence of DAA, which almost reacted with the hydrazine to yield the corresponding hydrazone. As a result, it was determined that contaminants in the cosmetic powder did not interfere with analysis of the hydrazone. Importantly, the molar absorptivity of the hydrazone (1.29 × 10 4 at 400 nm) is five times that of DAA (2.57 × 10 3 at 230 nm). Accordingly, detection of the hydrazone at 400 nm in a new analytical method might have fivefold higher sensitivity compared with that of DAA at 230 nm in the standard method.

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Studies on Photochemical Reactions of Air Pollutants. XIV. Photooxidation of Sulfur Dioxide in Air by Various Air Pollutants

Cited by 3 publications

References 27 publications

Photochemistry of SO₂ at the Air–Water Interface: A Source of OH and HOSO Radicals

Photochemistry of SO₂ at the Air–Water Interface: A Source of OH and HOSO Radicals

Classroom Illustrations of Acidic Air Pollution Using Nylon Fabric

Facile and Accurate Analysis of Sodium Dehydroacetate in Cosmetic Powders After Extraction by Na<sub>2</sub>CO<sub>3</sub>-Methanol-H<sub>2</sub>O and Derivatization with 4-Nitrophenylhydrazine∙HCl

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Studies on Photochemical Reactions of Air Pollutants. XIV. Photooxidation of Sulfur Dioxide in Air by Various Air Pollutants

Cited by 3 publications

References 27 publications

Photochemistry of SO2 at the Air–Water Interface: A Source of OH and HOSO Radicals

Photochemistry of SO2 at the Air–Water Interface: A Source of OH and HOSO Radicals

Classroom Illustrations of Acidic Air Pollution Using Nylon Fabric

Facile and Accurate Analysis of Sodium Dehydroacetate in Cosmetic Powders After Extraction by Na<sub>2</sub>CO<sub>3</sub>-Methanol-H<sub>2</sub>O and Derivatization with 4-Nitrophenylhydrazine∙HCl

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Photochemistry of SO₂ at the Air–Water Interface: A Source of OH and HOSO Radicals

Photochemistry of SO₂ at the Air–Water Interface: A Source of OH and HOSO Radicals