title: Fate of thiabendazole through the treatment of a simulated agro-food industrial effluent by combined MBR/Fenton processes at μg/L scale.
abstract: This study has been carried out to assess the performance of a combined system consisting of a membrane bioreactor (MBR) followed by an advanced oxidation process (Fenton/Photo-Fenton) for removing the fungicide thiabendazole (TBZ) in a simulated agro-food industrial wastewater. Previous studies have shown the presence of TBZ in the effluent of an agro-food industry treated by activated sludge in a sequencing batch reactor (SBR), thus reinforcing the need for alternative treatments for removal. In this study, a simulated agro-food industry effluent was enriched with 100 μg L(-1) TBZ and treated by combined MBR/Fenton and MBR/solar photo-Fenton systems. Samples were directly injected into a highly sensitive liquid chromatography-triple quadrupole-linear ion trap-mass spectrometer (LC-QqLiT-MS/MS) analytical system to monitor the degradation of TBZ even at low concentration levels (ng L(-1)). Results showed that the biological treatment applied was not effective in TBZ degradation, which remained almost unaltered; although most dissolved organic matter was biodegraded effectively. Fenton and solar photo-Fenton, were assayed as tertiary treatments. The experiments were run without any pH adjustment by using an iron dosage strategy in the presence of excess hydrogen peroxide. Both treatments resulted in a total degradation of TBZ, obtaining more than 99% removal in both cases. To assure the total elimination of contaminants in the treated waters, transformation products (TPs) of TBZ generated during Fenton degradation experiments were identified and monitored by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS/MS). Up to four TPs could be identified. Two of them corresponded to mono-hydroxylated derivatives, typically generated under hydroxyl radicals driven processes. The other two corresponded with the hydrolysis of the TBZ molecule to yield benzoimidazole and thiazole-4-carboxamidine. All of them were also degraded during the treatment.
authors.affiliation: Department of Chemical Engineering, University of Almería, 04120 Almería, Spain; CIESOL, Joint Centre of the University of Almería-CIEMAT, 04120 Almería, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Sánchez Peréz
authors.affiliation: Department of Chemical Engineering, University of Almería, 04120 Almería, Spain; CIESOL, Joint Centre of the University of Almería-CIEMAT, 04120 Almería, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Carra
authors.affiliation: Universidade Federal da Integração Latino-Americana (UNILA), PO Box 2044, CEP 85867-970 Foz do Iguaçu, PR, Brazil.
authors.forename: C
authors.initials: C
authors.lastname: Sirtori
authors.affiliation: CIESOL, Joint Centre of the University of Almería-CIEMAT, 04120 Almería, Spain; Department of Chemistry and Physics, University of Almería, 04120 Almería, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Agüera
authors.affiliation: Department of Chemical Engineering, University of Almería, 04120 Almería, Spain; CIESOL, Joint Centre of the University of Almería-CIEMAT, 04120 Almería, Spain. Electronic address: abgarcia@ual.es.
authors.forename: B
authors.initials: B
authors.lastname: Esteban
mesh_terms: D000383:Agriculture; D001673:Biodegradation, Environmental; D019149:Bioreactors; D002851:Chromatography, High Pressure Liquid; D006861:Hydrogen Peroxide; D007501:Iron; D008567:Membranes, Artificial; D053719:Tandem Mass Spectrometry; D013827:Thiabendazole / Q000378:metabolism*; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000379:methods*
chemical_list: D006861:Hydrogen Peroxide; D007501:Iron; D008567:Membranes, Artificial; D013827:Thiabendazole; D062065:Wastewater; D014874:Water Pollutants, Chemical; C045076:Fenton's reagent
keywords: Fenton; LC-QLiT-MS/M; LC-QTOF-MS/MS; Membrane bioreactor; Thiabendazole; Transformation products