title: Treatment of solutions containing nonylphenol ethoxylate by photoelectrooxidation.
abstract: In this work the photoelectrooxidation (PEO) was applied in the treatment of a solution containing nonylphenol ethoxylate surfactant (NP4EO). The use of different lamps (125 and 250 W), current density (5 and 10 mA cm(-2)) and treatment time (0, 60, 120, 180 and 240 min) were investigated. The samples were characterized by UV/Vis, total organic carbon (TOC), gas chromatography associated to mass spectroscopy (GC/MS) and ecotoxicity. The reaction kinetics were calculated and the light flux and pH were measured. The results of analysis by UV/Vis show that there is degradation of nonylphenol ethoxylated in the treatment time of 240 min for all configurations, and the configurations that used a 250 W lamp and a current density of 10 mA cm(-2) obtained better results, with a reduction of 83% in TOC, indicating a high mineralization of the surfactant. It was further found in the GC/MS that the configurations that used the 125 W lamp promoted a smaller incident light flux on the solution, and, regardless of the applied current density, it was generated the reaction intermediate nonylphenol, more toxic than the parent compound. The opposite can be observed when a 250 W lamp was used, which produced a higher incident light flux. Based on the degradation products detected, a simplified mechanism for degradation of nonylphenol ethoxylate was proposed. Although a treatment time of 240 min with photoelectrooxidation with different configurations was not effective in the complete mineralization of the compound, a promising process was developed with the treatment using a lamp of 250 W and a current density of 10 mA cm(-2), which generated a solution with less toxicity than the original one.
authors.affiliation: Universidade Federal do Rio Grande do Sul (UFRGS) - Programa de Pós-Graduação em Engenharia de Minas, Metalúrgica e de Materiais (PPGE3M), Av. Bento Gonçalves, 9500 Porto Alegre, RS, Brazil.
authors.forename: Salatiel Wohlmuth
authors.initials: SW
authors.lastname: da Silva
authors.affiliation: Universidade Federal do Rio Grande do Sul (UFRGS) - Programa de Pós-Graduação em Engenharia de Minas, Metalúrgica e de Materiais (PPGE3M), Av. Bento Gonçalves, 9500 Porto Alegre, RS, Brazil.
authors.forename: Gustavo Lanferdini
authors.initials: GL
authors.lastname: Bordignon
authors.affiliation: Universidade Feevale, Campus II ERS-239, 2755, Novo Hamburgo, RS, Brazil.
authors.forename: Cheila
authors.initials: C
authors.lastname: Viegas
authors.affiliation: Universidade Feevale, Campus II ERS-239, 2755, Novo Hamburgo, RS, Brazil.
authors.forename: Marco Antônio Siqueira
authors.initials: MA
authors.lastname: Rodrigues
authors.affiliation: Universidade Federal do Rio Grande do Sul (UFRGS) - Laboratório de Ecotoxicologia, Centro de Ecologia, Av. Bento Gonçalves, 9500, Setor 4, Prédio 43411, Sala 213, Porto Alegre, RS, Brazil.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Arenzon
authors.affiliation: Universidade Federal do Rio Grande do Sul (UFRGS) - Programa de Pós-Graduação em Engenharia de Minas, Metalúrgica e de Materiais (PPGE3M), Av. Bento Gonçalves, 9500 Porto Alegre, RS, Brazil. Electronic address: amb@ufrgs.br.
authors.forename: Andréa Moura
authors.initials: AM
authors.lastname: Bernardes
mesh_terms: D055664:Electrochemical Techniques; D005026:Ethylene Glycols / Q000737:chemistry* / Q000528:radiation effects*; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D055668:Photochemical Processes; D012996:Solutions; D013501:Surface-Active Agents / Q000737:chemistry* / Q000528:radiation effects*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000528:radiation effects; D018508:Water Purification / Q000379:methods
chemical_list: D005026:Ethylene Glycols; D012996:Solutions; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C021754:terics
keywords: Advanced oxidation process; Endocrine disruptor; Nonylphenol ethoxylate; Photoeletectrooxidation