title: Ultrasonic-assisted ozone oxidation process of triphenylmethane dye degradation: evidence for the promotion effects of ultrasonic on malachite green decolorization and degradation mechanism.
abstract: This study aimed to prove the promotion effects of ultrasonic on malachite green (MG) decolorization in the ultrasonic-assisted ozone oxidation process (UAOOP), and propose the possible pathway of MG degradation. The decolorization of MG followed an apparent pseudo first-order kinetic law (initial MG concentration 100-1000 mg/L). When ultrasonic (US) was applied with ozone simultaneously, the apparent pseudo-first-order rate constant (K(app)) increased, and the time MG decolorized to the half of initial concentration (T(1/2)) shortened 185 s (1000 mg/L). Moreover, the stoichiometric ratio (Z(app)) between O(3) and MG was enhanced by US to 2.0 mol, saving 11% oxidant addition, comparing to individual ozone process. These results indicated that the application of US can reduce reaction time and dose of ozone addition. The possible pathway of MG degradation included three major approaches. And the result suggested that the reaction between MG and hydroxyl radical was substitution reaction rather than adduct reaction.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
authors.forename: Xian-Jiao
authors.initials: XJ
authors.lastname: Zhou
authors.forename: Wan-Qian
authors.initials: WQ
authors.lastname: Guo
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Yang
authors.forename: He-Shan
authors.initials: HS
authors.lastname: Zheng
authors.forename: Nan-Qi
authors.initials: NQ
authors.lastname: Ren
mesh_terms: D001673:Biodegradation, Environmental; D004396:Coloring Agents / Q000737:chemistry / Q000528:radiation effects; D019220:High-Energy Shock Waves; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D011829:Radiation Dosage; D012394:Rosaniline Dyes / Q000737:chemistry* / Q000528:radiation effects*; D013010:Sonication; D014320:Triphenylmethyl Compounds / Q000737:chemistry* / Q000528:radiation effects*
chemical_list: D004396:Coloring Agents; D012394:Rosaniline Dyes; D014320:Triphenylmethyl Compounds; C005095:malachite green; D010126:Ozone; C046945:triphenylmethane