title: Ultrasonic degradation of 1-H-benzotriazole in water.
abstract: This paper reports on the effect of different parameters of ultrasonic power, pollutant initial concentration, pH and the presence of co-existing chemical species (oxygen, nitrogen, ozone, and radical scavengers) on the ultrasonic degradation of the endocrine disruptor 1-H-benzotriazole. Increasing the 1-H-benzotriazole initial concentration from 41.97 to 167.88 μM increased the pollutant degradation rate by 40%. Likewise, a high applied ultrasonic power enhanced the extent of 1-H-benzotriazole removal and its initial degradation rate, which was accelerated in the presence of ozone and oxygen, but inhibited by nitrogen. The most favorable pH for the ultrasonic degradation was acidic media, reaching ∼90% pollutant removal in 2 h. The hydroxyl free radical concentration in the reaction medium was proportional to the ultrasound power and the irradiation time. Kinetic models based on a Langmuir-type mechanism were used to predict the pollutant sonochemical degradation. It was concluded that degradation takes place at both the bubble-liquid interfacial region and in the bulk solution, and OH radicals were the main species responsible for the reaction. Hydroxyl free radicals were generated by water pyrolysis and then diffused into the interfacial region and the bulk solution where most of the solute molecules were present.
authors.affiliation: Grupo GDCON, Facultad de Ingeniería, Sede de Investigación Universitaria (SIU), Universidad de Antioquia, Calle 70 No. 52 -21, Medellín, Colombia.
authors.forename: Henry
authors.initials: H
authors.lastname: Zúñiga-Benítez
authors.affiliation: Department of Chemical and Biological Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9, Canada E-mail: j.soltan@usask.ca.
authors.forename: Jafar
authors.initials: J
authors.lastname: Soltan
authors.affiliation: Grupo GDCON, Facultad de Ingeniería, Sede de Investigación Universitaria (SIU), Universidad de Antioquia, Calle 70 No. 52 -21, Medellín, Colombia.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Peñuela
mesh_terms: D057919:Biological Oxygen Demand Analysis; D002244:Carbon / Q000737:chemistry; D016166:Free Radical Scavengers; D005609:Free Radicals; D005740:Gases; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical; D007700:Kinetics; D010100:Oxygen / Q000737:chemistry; D010126:Ozone / Q000737:chemistry; D012996:Solutions; D013010:Sonication; D013997:Time Factors; D014230:Triazoles / Q000032:analysis / Q000737:chemistry*; D014465:Ultrasonics; D014463:Ultrasonography / Q000379:methods; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D016166:Free Radical Scavengers; D005609:Free Radicals; D005740:Gases; D012996:Solutions; D014230:Triazoles; D014874:Water Pollutants, Chemical; D014867:Water; D017665:Hydroxyl Radical; D010126:Ozone; D002244:Carbon; C012771:benzotriazole; D010100:Oxygen