title: Sequential ozone advanced oxidation and biological oxidation processes to remove selected pharmaceutical contaminants from an urban wastewater.
abstract: Sequential treatments consisting in a chemical process followed by a conventional biological treatment, have been applied to remove mixtures of nine contaminants of pharmaceutical type spiked in a primary sedimentation effluent of a municipal wastewater. Combinations of ozone, UVA black light (BL) and Fe(III) or Fe₃O₄ catalysts constituted the chemical systems. Regardless of the Advanced Oxidation Process (AOP), the removal of pharmaceutical compounds was achieved in 1 h of reaction, while total organic carbon (TOC) only diminished between 3.4 and 6%. Among selected ozonation systems to be implemented before the biological treatment, the application of ozone alone in the pre-treatment stage is recommended due to the increase of the biodegradability observed. The application of ozone followed by the conventional biological treatment leads high TOC and COD removal rates, 60 and 61%, respectively, and allows the subsequent biological treatment works with shorter hydraulic residence time (HRT). Moreover, the influence of the application of AOPs before and after a conventional biological process was compared, concluding that the decision to take depends on the characterization of the initial wastewater with pharmaceutical compounds.
authors.affiliation: a Departamento de Ingeniería Química y Química Física , Universidad de Extremadura , Badajoz , Spain.
authors.forename: Azahara
authors.initials: A
authors.lastname: Espejo
authors.forename: Almudena
authors.initials: A
authors.lastname: Aguinaco
authors.forename: J F
authors.initials: JF
authors.lastname: García-Araya
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Beltrán
mesh_terms: D002384:Catalysis; D002947:Cities; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D004364:Pharmaceutical Preparations / Q000737:chemistry* / Q000378:metabolism; D012722:Sewage / Q000382:microbiology; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000378:metabolism
chemical_list: D052203:Ferrosoferric Oxide; D007501:Iron; D010126:Ozone; D004364:Pharmaceutical Preparations; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Aerobic processes; biodegradation; emerging contaminants; environmental preservation; ozone advanced oxidation processes; wastewater treatment