title: Ozone direct oxidation kinetics of Cationic Red X-GRL in aqueous solution.
abstract: This study characterizes the ozonation of the azo dye Cationic Red X-GRL in the presence of TBA (tert-butyl alcohol), a scavenger of hydroxyl radical, in a bubble column reactor. Effects of oxygen flow rate, temperature, initial dye concentration, and pH were investigated through a series of batch tests. Generally, enhancing oxygen flow rate enhanced the removal of dye. However, there was a minimum removal of dye at temperature 298 K. Increasing or decreasing temperature enhanced the degradation of dye. Increasing the initial dye concentration decreased the removal of dye while the ozonation rate increased. The rate constants and the kinetic regime of the reaction between ozone and dye were obtained by fitting the experimental data to a kinetics model based on a second order overall reaction, first order with respect to both ozone and dye. The Hatta numbers of the reactions were between 0.039 and 0.083, which indicated that the reaction occurred in the liquid bulk. The direct oxidation rate constant k(D) was correlated with temperature by a modified Arrhenius Equation with an activation energy E(a) of 15.538 kJ mol(-1).
authors.affiliation: Department of Environmental Engineering, Zhejiang University, Hangzhou 310027, China. weirong@mail.hz.zj.cn
authors.forename: Weirong
authors.initials: W
authors.lastname: Zhao
authors.forename: Zhongbiao
authors.initials: Z
authors.lastname: Wu
authors.forename: Dahui
authors.initials: D
authors.lastname: Wang
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D007700:Kinetics; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D012996:Solutions
chemical_list: D001391:Azo Compounds; D002412:Cations; C516485:Red X-GRL; D012996:Solutions; D010126:Ozone