title: Decomposition of an azo dye in aqueous solution by combination of ultrasound and visible light.
abstract: The degradation of Acid Orange 7 in aqueous solution has been investigated under the irradiation of ultrasound and visible light respectively and simultaneously. We have observed that the maximum removal percentage K increases from 4% to 35% when the ultrasonic frequency f and power P change from f=20 KHz and P=3 W to f=1 MHz and P=40 W. On the other hand, the K-value is approximately 3% under the irradiation of visible light at 632 nm and 100 mW/mm(2). Under the simultaneous irradiation of ultrasound (1 MHz, 40 W) and visible light (632 nm, 100 mW/mm(2)), the K-value reaches to approximately 65%, indicating a synergistic effect of ultrasound and visible light irradiations. A simple model based on the band gap theory and cavitation theory is proposed to explain the synergistic phenomenon.
authors.affiliation: State Key Lab of Modern Acoustics, Nanjing University, Nanjing 210093, China.
authors.forename: C Y
authors.initials: CY
authors.lastname: Ma
authors.forename: J Y
authors.initials: JY
authors.lastname: Xu
authors.forename: X J
authors.initials: XJ
authors.lastname: Liu
mesh_terms: D001391:Azo Compounds / Q000737:chemistry* / Q000302:isolation & purification / Q000528:radiation effects*; D001557:Benzenesulfonates; D004396:Coloring Agents / Q000737:chemistry / Q000302:isolation & purification / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D007220:Industrial Waste / Q000517:prevention & control; D008027:Light; D011829:Radiation Dosage; D012996:Solutions; D013010:Sonication; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification / Q000528:radiation effects*; D018508:Water Purification / Q000379:methods
chemical_list: D001391:Azo Compounds; D001557:Benzenesulfonates; D004396:Coloring Agents; D007220:Industrial Waste; D012996:Solutions; D014874:Water Pollutants, Chemical; D014867:Water; C014722:2-naphthol orange