title: Removal of dimethyl phthalate from water by ozone microbubbles.
abstract: This work investigates the removal of dimethyl phthalate (DMP) from water using ozone microbubbles in a pilot plant of 20 dm3capacity. Experiments were performed under various reaction conditions to examine the effects of the initial concentration of DMP, pH of the medium, ozone generation rate, and the role of H2O2on the removal of DMP. The DMP present in water was effectively removed by the ozone microbubbles. The removal was effective in neutral and alkaline media. Increase in the initial concentration of the target pollutant negatively affected its removal efficiency. The removal efficiency dramatically increased from 1% to 99% when the ozone generation rate was increased from 0.28 to 1.94 mg s-1at pH 7. The total organic carbon measurements revealed that a complete mineralization of DMP was achieved within 1.8 ks at the high ozone feed rate. The use of t-butyl alcohol as the hydroxyl radical scavenger confirmed that the reaction between the target organic compound and ·OH radical dominated over its direct reaction with ozone. The reaction between DMP and ozone followed an overall second-order kinetics. The volumetric mass transfer coefficient of ozone in the reacting system and the enhancement factor increased with increasing initial concentration of DMP. Very low values of Hatta number were obtained at all initial concentrations of DMP and pH, which show that the mass transfer resistance was small.
authors: a Department of Chemical Engineering , Indian Institute of Technology Guwahati , Guwahati , India.
authors: Abdisa
authors: A
authors: Jabesa
authors: a Department of Chemical Engineering , Indian Institute of Technology Guwahati , Guwahati , India.
authors: Pallab
authors: P
authors: Ghosh
mesh_terms: D006861:Hydrogen Peroxide; D007700:Kinetics; D045423:Microbubbles; D010126:Ozone; D014867:Water; D014874:Water Pollutants, Chemical; D018508:Water Purification
chemical_list: D014874:Water Pollutants, Chemical; D014867:Water; D010126:Ozone; D006861:Hydrogen Peroxide
keywords: Dimethyl phthalate; hydroxyl radical; kinetics; microbubbles; ozone