title: Degradation alternatives for a commercial fungicide in water: biological, photo-Fenton, and coupled biological photo-Fenton processes.
abstract: Imazalil (IMZ) is a widely used fungicide for the post-harvest treatment of citrus, classified as "likely to be carcinogenic in humans" for EPA, that can be only partially removed by conventional biological treatment. Consequently, specific or combined processes should be applied to prevent its release to the environment. Biological treatment with adapted microorganism consortium, photo-Fenton, and coupled biological photo-Fenton processes were tested as alternatives for the purification of water containing high concentration of the fungicide and the coadjutants present in the commercial formulation. IMZ-resistant consortium with the capacity to degrade IMZ in the presence of a C-rich co-substrate was isolated from sludge coming from a fruit packaging company wastewater treatment plant. This consortium was adapted to resist and degrade the organics present in photo-Fenton-oxidized IMZ water solution. Bacteria colonies from the consortia were isolated and identified. The effect of H2O2initial concentration and dosage on IMZ degradation rate, average oxidation state (AOS), organic acid concentration, oxidation, and mineralization percentage after photo-Fenton process was determined. The application of biological treatment to the oxidized solutions notably decreased the total organic carbon (TOC) in solution. The effect of the oxidation degree, limited by H2O2concentration and dosage, on the percentage of mineralization obtained after the biological treatment was determined and explained in terms of changes in AOS. The concentration of H2O2necessary to eliminate IMZ by photo-Fenton and to reduce TOC and chemical oxygen demand (COD) by biological treatment, in order to allow the release of the effluents to rivers with different flows, was estimated.
authors.affiliation: 3iA-UNSAM, Instituto de Investigación e Ingeniería Ambiental, CONICET, Universidad Nacional de San Martín, Campus Miguelete, Av. 25 de mayo y Francia, B1650HMP General San Martín, Provincia de Buenos Aires, Argentina.
authors.forename: Elsa
authors.initials: E
authors.lastname: López-Loveira
authors.affiliation: 3iA-UNSAM, Instituto de Investigación e Ingeniería Ambiental, CONICET, Universidad Nacional de San Martín, Campus Miguelete, Av. 25 de mayo y Francia, B1650HMP General San Martín, Provincia de Buenos Aires, Argentina.
authors.forename: Federico
authors.initials: F
authors.lastname: Ariganello
authors.affiliation: 3iA-UNSAM, Instituto de Investigación e Ingeniería Ambiental, CONICET, Universidad Nacional de San Martín, Campus Miguelete, Av. 25 de mayo y Francia, B1650HMP General San Martín, Provincia de Buenos Aires, Argentina.
authors.forename: María Sara
authors.initials: MS
authors.lastname: Medina
authors.affiliation: IMPAM-UBA, Laboratorio de Investigaciones en Mecanismos y Resistencias a Antibióticos, CONICET, Universidad Nacional de Buenos Aires, Paraguay 2155, C1121ABG, Ciudad de Buenos Aires, Argentina.
authors.forename: Daniela
authors.initials: D
authors.lastname: Centrón
authors.affiliation: 3iA-UNSAM, Instituto de Investigación e Ingeniería Ambiental, CONICET, Universidad Nacional de San Martín, Campus Miguelete, Av. 25 de mayo y Francia, B1650HMP General San Martín, Provincia de Buenos Aires, Argentina. rjcandal@gmail.com.
authors.forename: Roberto
authors.identifier: http://orcid.org/0000-0001-8606-2752
authors.initials: R
authors.lastname: Candal
authors.affiliation: 3iA-UNSAM, Instituto de Investigación e Ingeniería Ambiental, CONICET, Universidad Nacional de San Martín, Campus Miguelete, Av. 25 de mayo y Francia, B1650HMP General San Martín, Provincia de Buenos Aires, Argentina.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Curutchet
mesh_terms: D001673:Biodegradation, Environmental; D018857:Food Packaging; D005659:Fungicides, Industrial / Q000737:chemistry* / Q000378:metabolism / Q000528:radiation effects; D007093:Imidazoles / Q000737:chemistry* / Q000378:metabolism / Q000528:radiation effects; D059013:Microbial Consortia / Q000502:physiology*; D010084:Oxidation-Reduction; D010782:Photolysis; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000378:metabolism / Q000528:radiation effects
chemical_list: D005659:Fungicides, Industrial; D007093:Imidazoles; D014874:Water Pollutants, Chemical; C017435:enilconazole
keywords: Bioremediation; Coupled treatment; Imazalil; Photo-Fenton