title: Degradation of the insecticide propoxur by electrochemical advanced oxidation processes using a boron-doped diamond/air-diffusion cell.
abstract: A solution with 0.38 mM of the pesticide propoxur (PX) at pH 3.0 has been comparatively treated by electrochemical oxidation with electrogenerated H2O2(EO-H2O2), electro-Fenton (EF), and photoelectro-Fenton (PEF). The trials were carried out with a 100-mL boron-doped diamond (BDD)/air-diffusion cell. The EO-H2O2process had the lowest oxidation ability due to the slow reaction of intermediates with•OH produced from water discharge at the BDD anode. The EF treatment yielded quicker mineralization due to the additional•OH formed between added Fe2+and electrogenerated H2O2. The PEF process was the most powerful since it led to total mineralization by the combined oxidative action of hydroxyl radicals and UVA irradiation. The PX decay agreed with a pseudo-first-order kinetics in EO-H2O2, whereas in EF and PEF, it obeyed a much faster pseudo-first-order kinetics followed by a much slower one, which are related to the oxidation of its Fe(II) and Fe(III) complexes, respectively. EO-H2O2showed similar oxidation ability within the pH range 3.0-9.0. The effect of current density and Fe2+and substrate contents on the performance of the EF process was examined. Two primary aromatic products were identified by LC-MS during PX degradation.
authors.affiliation: Instituto de Química (INQUI), Universidade Federal de Mato Grosso do Sul, 549, Av. Senador Filinto Muller 1555, 79070-900, Campo Grande, Mato Grosso do Sul, Brazil.
authors.forename: Diego Roberto Vieira
authors.initials: DRV
authors.lastname: Guelfi
authors.affiliation: Instituto de Química (INQUI), Universidade Federal de Mato Grosso do Sul, 549, Av. Senador Filinto Muller 1555, 79070-900, Campo Grande, Mato Grosso do Sul, Brazil.
authors.forename: Fábio
authors.initials: F
authors.lastname: Gozzi
authors.affiliation: Laboratori d'Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, c/Martí i Franquès 1-11, 08028, Barcelona, Spain.
authors.forename: Ignasi
authors.initials: I
authors.lastname: Sirés
authors.affiliation: Laboratori d'Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, c/Martí i Franquès 1-11, 08028, Barcelona, Spain.
authors.forename: Enric
authors.initials: E
authors.lastname: Brillas
authors.affiliation: Instituto de Química (INQUI), Universidade Federal de Mato Grosso do Sul, 549, Av. Senador Filinto Muller 1555, 79070-900, Campo Grande, Mato Grosso do Sul, Brazil.
authors.forename: Amílcar
authors.initials: A
authors.lastname: Machulek
authors.affiliation: Instituto de Química (INQUI), Universidade Federal de Mato Grosso do Sul, 549, Av. Senador Filinto Muller 1555, 79070-900, Campo Grande, Mato Grosso do Sul, Brazil. scolive@gmail.com.
authors.forename: Silvio César
authors.identifier: http://orcid.org/0000-0002-2820-932X
authors.initials: SC
authors.lastname: de Oliveira
mesh_terms: D001895:Boron / Q000737:chemistry*; D018130:Diamond / Q000737:chemistry*; D007306:Insecticides / Q000032:analysis / Q000737:chemistry; D010084:Oxidation-Reduction; D001074:Propoxur / Q000032:analysis / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry; D018508:Water Purification
chemical_list: D007306:Insecticides; D014874:Water Pollutants, Chemical; D018130:Diamond; D001074:Propoxur; D001895:Boron
keywords: Electro-Fenton; Electrochemical oxidation; Hydroxyl radical; Oxidation products; Photoelectro-Fenton; Photolysis; Propoxur; Water treatment