title: Degradation of dibromophenols by UV irradiation.
abstract: We examined the degradation of dibromophenols (DBPs), i.e. 2,4-DBP, 2,6-DBP and 3,5-DBP by ultraviolet (UV) irradiation and estimated the relationship between degradability and molecular orbital properties of each dibromophenol. The removal of DBPs under a UV lamp system was successfully performed in an aqueous solution. After 5 min of irradiation, the initial DBPs concentration of 20 mg/L was decreased to below 1 mg/L, and about 60% of bromide ion was released. A decrease in the concentration of dissolved organic carbon (DOC) suggested the mineralization of DBPs. The mineralization may occur after release of bromide ions because the decrease of DOC was slower than the release of bromide ions. The degradability of 3,5-DBP was slightly lower than 2,6-DBP and 2,4-DBP. Molecular orbital calculation suggested that the electrophilic frontier density and the highest occupied molecular orbital (HOMO) energy may be related to the degradability of DBPs.
authors: Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu 400-8511, Japan. Electronic address: keikokh@yamanashi.ac.jp.
authors: Keiko
authors: K
authors: Katayama-Hirayama
authors: Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu 400-8511, Japan.
authors: Naoki
authors: N
authors: Toda
authors: Technology Development Division, Toshiba Lighting and Technology Corporation, Asahimachi 5-2-1, Imabari, Ehime 794-8510, Japan.
authors: Akihiko
authors: A
authors: Tauchi
authors: Technology Development Division, Toshiba Lighting and Technology Corporation, Asahimachi 5-2-1, Imabari, Ehime 794-8510, Japan.
authors: Atsushi
authors: A
authors: Fujioka
authors: Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu 400-8511, Japan.
authors: Tetsuya
authors: T
authors: Akitsu
authors: Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu 400-8511, Japan.
authors: Hidehiro
authors: H
authors: Kaneko
authors: Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu 400-8511, Japan.
authors: Kimiaki
authors: K
authors: Hirayama
mesh_terms: D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry* / Q000528:radiation effects; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D010636:Phenols; D014874:Water Pollutants, Chemical; C038964:2,6-dibromophenol; C013930:2,4-dibromophenol
keywords: DOC; UV irration; bromide ion; dibromophenol; mineralization