title: Iohexol degradation in wastewater and urine by UV-based Advanced Oxidation Processes (AOPs): Process modeling and by-products identification.
abstract: In this work, an Iodinated Contrast Medium (ICM), Iohexol, was subjected to treatment by 3 Advanced Oxidation Processes (AOPs) (UV, UV/H2O2, UV/H2O2/Fe2+). Water, wastewater and urine were spiked with Iohexol, in order to investigate the treatment efficiency of AOPs. A tri-level approach has been deployed to assess the UV-based AOPs efficacy. The treatment was heavily influenced by the UV transmittance and the organics content of the matrix, as dilution and acidification improved the degradation but iron/H2O2increase only moderately. Furthermore, optimization of the treatment conditions, as well as modeling of the degradation was performed, by step-wise constructed quadratic or product models, and determination of the optimal operational regions was achieved through desirability functions. Finally, global chemical parameters (COD, TOC and UV-Vis absorbance) were followed in parallel with specific analyses to elucidate the degradation process of Iohexol by UV-based AOPs. Through HPLC/MS analysis the degradation pathway and the effects the operational parameters were monitored, thus attributing the pathways the respective modifications. The addition of iron in the UV/H2O2process inflicted additional pathways beneficial for both Iohexol and organics removal from the matrix.
authors.affiliation: SB, ISIC, Group of Advanced Oxidation Processes, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, 1015 Lausanne, Switzerland. Electronic address: Stefanos.Giannakis@epfl.ch.
authors.forename: Stefanos
authors.initials: S
authors.lastname: Giannakis
authors.affiliation: Laboratoire d'Electrochimie Physique et Analytique, École Polytechnique Fédérale de Lausanne - Valais Wallis, 1951 Sion, Switzerland.
authors.forename: Milica
authors.initials: M
authors.lastname: Jovic
authors.affiliation: Laboratoire d'Electrochimie Physique et Analytique, École Polytechnique Fédérale de Lausanne - Valais Wallis, 1951 Sion, Switzerland.
authors.forename: Natalia
authors.initials: N
authors.lastname: Gasilova
authors.affiliation: Escola Tècnica Superior d'Enginyeria Química (ETSEQ), Universitat Rovira i Virgili (URV), 43007 Tarragona, Spain.
authors.forename: Miquel
authors.initials: M
authors.lastname: Pastor Gelabert
authors.affiliation: SB, ISIC, Group of Advanced Oxidation Processes, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, 1015 Lausanne, Switzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Schindelholz
authors.affiliation: SB, Physics Section Management, École Polytechnique Fédérale de Lausanne (EPFL), Station 3, 1015 Lausanne, Switzerland.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Furbringer
authors.affiliation: Laboratoire d'Electrochimie Physique et Analytique, École Polytechnique Fédérale de Lausanne - Valais Wallis, 1951 Sion, Switzerland.
authors.forename: Hubert
authors.initials: H
authors.lastname: Girault
authors.affiliation: SB, ISIC, Group of Advanced Oxidation Processes, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, 1015 Lausanne, Switzerland. Electronic address: Cesar.Pulgarin@epfl.ch.
authors.forename: César
authors.initials: C
authors.lastname: Pulgarin
mesh_terms: D006861:Hydrogen Peroxide / Q000737:chemistry; D007472:Iohexol; D010084:Oxidation-Reduction; D014466:Ultraviolet Rays; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification
chemical_list: D006861:Hydrogen Peroxide; D007472:Iohexol; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Advanced Oxidation Process; Degradation pathway; Iodinated Contrast Media; Modeling and optimization; Urine purification; Wastewater treatment