title: Application of advanced oxidation processes to doxycycline and norfloxacin removal from water.
abstract: Doxycycline (Dxy) and Norfloxacin (Nfx) have been oxidized by means of different technologies of increasing complexity. Preliminary experiments showed that activated carbon adsorption (1.0 g L⁻¹) of these antibiotics (C(Antibiotic) = 5 × 10⁻⁵ M) led to a 60 and 85 % of total organic carbon (TOC) removal, however, a significant decrease in adsorption capacity was experienced after several reuses of the adsorbent. UV-C irradiation of Dxy (20 % removal in 2 h) or Nfx (90 % removal in 2 h) did not affect the initial TOC content of the solution while single ozonation (C(O₃) gas inlet concentration = 15.0 ppm) led to the instantaneous disappearance of the parent compounds while TOC conversion values in the proximity of 40 % were obtained. Complex systems based on the combination of ozone, UV-C radiation, titanium dioxide and activated carbon led to similar TOC removals of the order of 70 and 65 % for Dxy and Nfx, respectively. An attempt has been made to calculate the quantum yield and direct ozonation rate constants for doxycycline and norfloxacin. Additionally, the best systems, i.e., the O₃ and O₃/UV-C processes, have been simulated by a pseudoempirical model by considering TOC as a surrogate parameter.
authors: Departamento de Ingeniería Química y Química Física, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain. fjrivas@unex.es
authors: Javier
authors: J
authors: Rivas
authors: Angel
authors: A
authors: Encinas
authors: Fernando
authors: F
authors: Beltrán
authors: Nigel
authors: N
authors: Graham
mesh_terms: D000327:Adsorption; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000528:radiation effects; D002606:Charcoal / Q000737:chemistry; D004318:Doxycycline / Q000737:chemistry / Q000302:isolation & purification* / Q000528:radiation effects; D007700:Kinetics; D009643:Norfloxacin / Q000737:chemistry / Q000302:isolation & purification* / Q000528:radiation effects; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry; D014025:Titanium / Q000737:chemistry; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification* / Q000528:radiation effects; D018508:Water Purification / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D002606:Charcoal; D010126:Ozone; D014025:Titanium; D009643:Norfloxacin; D004318:Doxycycline