Active oxygen species generated during chlorination and ozonation

Autor:	Hiroaki Nagaoka, Hideo Utsumi, Masafumi Hakoda, Satoko Shimbara, Akira Hamada, Youn-son Chung
Rok vydání:	1994
Předmět:	Pollutant Environmental Engineering Radical Inorganic chemistry chemistry.chemical_element Photochemistry law.invention Active oxygen chemistry law Reagent polycyclic compounds Ultraviolet irradiation Chlorine Water treatment Electron paramagnetic resonance Water Science and Technology
Zdroj:	Water Science and Technology. 30:91-99
ISSN:	1996-9732 0273-1223
DOI:	10.2166/wst.1994.0451
Popis:	In water treatment, ultraviolet irradiation, ozonation, and chlorination are believed to produce various active oxygen species, which seem to participate in reactions with fumic acid, pollutants and bacteria. It was, however, very difficult to determine the actual kinds and amount of active oxygen during the processes because of deficiencies of method. In order to determine the kinds and amounts of active oxygen species which may participate in water treatment process, the spin-trapping ESR (electron spin resonance) technique was applied to measuring unstable free radicals generated during chlorination and ozonation. As spin-trapping reagent, DMPO (5,5-dimethyl-1-pyrroline-N-oxide) was dissolved in phosphate-buffered water, and the solution was treated by either chlorination or ozonation. Immediately after the treatment, ESR spectrum was measured at room temperature. Typical ESR spectra due to DMPO-OH were observed from both treatments, indicating the generation of hydroxy radical in chlorination and ozonation. In addition to DMPO-OH, several different signals were observed and their appearance depended on the chlorine or ozone concentration.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c60d1d1888bd1aed8e467ea3cc3e42b0 https://doi.org/10.2166/wst.1994.0451 Zobrazit plný text záznamu