title: Mechanism and kinetic considerations of TOC removal from the powdered activated carbon ozonation of diclofenac aqueous solutions.
abstract: Ozonation of DCF in aqueous solution in the presence of powdered activated carbon (PAC) has been studied for mechanistic and kinetic purposes. The effects of gas flow rate, ozone gas concentration and initial TOC on the TOC elimination rate were then investigated. The use of PAC allows liquid-solid and internal diffusion mass transfer resistances being eliminated. Gas-liquid mass transfer resistance is also eliminated when ozonation is applied to DCF preozonated solutions. In the absence of mass transfer resistances a mechanism of reactions involving homogeneous and heterogeneous steps for TOC removal was proposed. From this mechanism a mathematical model constituted by mass balances of main species in water was established. Considerations about the changing nature of ozonation intermediates, as being promoters or inhibitors of ozone decomposition, is a key point to better predict the experimental concentrations of species present in this system.
authors.affiliation: Departamento de Ingeniería Química y Química Física, Universidad de Extremadura, 06071 Badajoz, Spain. fbeltran@unex.es
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Beltrán
authors.forename: J Pablo
authors.initials: JP
authors.lastname: Pocostales
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Alvarez
authors.forename: Josefa
authors.initials: J
authors.lastname: Jaramillo
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal; D002244:Carbon; D002606:Charcoal; D004008:Diclofenac / Q000737:chemistry*; D007700:Kinetics; D010126:Ozone / Q000737:chemistry*; D011208:Powders; D012996:Solutions
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D011208:Powders; D012996:Solutions; D004008:Diclofenac; D002606:Charcoal; D010126:Ozone; D002244:Carbon