TY - JOUR
T1 - Degradation of the antibiotic trimethoprim by electrochemical advanced oxidation processes using a carbon-PTFE air-diffusion cathode and a boron-doped diamond or platinum anode
AU - Moreira, Francisca C.
AU - Garcia-Segura, Sergi
AU - Boaventura, Rui A.R.
AU - Brillas, Enric
AU - Vilar, Vítor J.P.
N1 - Funding Information:
Financial support was partially provided by (i) project Pest-C/EQB/LA0020/2013, financed by FEDER through COMPETE – Programa Operacional Factores de Competitividade, (ii) FCT – Fundação para a Ciência e a Tecnologia, (iii) QREN and (iv) ON2. F.C. Moreira acknowledges her Doctoral fellowship SFRH/BD/80361/2011 supported by FCT. S. Garcia-Segura thanks the Doctoral grant awarded from MEC (Ministerio de Educación y Ciencia, Spain). V.J.P. Vilar acknowledges the FCT Investigator 2013 Programme (IF/01501/2013).
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/11
Y1 - 2014/11
N2 - The degradation of 20.0mgL-1 of trimethoprim (TMP), an antibiotic commonly detected in wastewaters, in an aqueous solution with 7.0gL-1 Na2SO4 was accomplished by electrochemical advanced oxidation processes (EAOPs) such as anodic oxidation with electrogenerated H2O2 (AO-H2O2), electro-Fenton (EF), photoelectro-Fenton (PEF) and solar photoelectro-Fenton (SPEF), as well as by the classical Fenton and photo-Fenton processes. All experiments were performed in a novel 2.2L lab-scale flow plant equipped with compound parabolic collectors (CPCs) and an electrochemical filter-press cell with a BDD or Pt anode and a carbon-PTFE air-diffusion cathode to electrogenerate H2O2. The effect of initial Fe2+ concentration, current density and pH on the PEF method with the BDD anode (PEF-BDD) was firstly assessed by means of TMP and dissolved organic carbon (DOC) decays, aiming to establish a treatment process using minimal iron concentration, adequate current density/H2O2 production and maximal pH. This treatment was efficiently performed using a low Fe2+ dose of 2.0mgL-1, a low current density of 5mAcm-2 and pH of 3.5 without iron precipitation. The relative oxidation ability of EAOPs using the BDD/air-diffusion cell increased in the order: AO-H2O2<EF<PEF<SPEF. The EF-BDD and PEF-BDD processes were more effective than the comparable Fenton and photo-Fenton ones. The PEF-BDD process exhibited slightly faster TMP degradation than the PEF-Pt one, whereas in SPEF the influence of the anode was almost negligible. After ca. 37kJL-1 UV energy, 77 and 73% mineralization with 30 and 26% current efficiency and 1.2 and 0.9kWhm-3 energy cost were obtained, respectively. It was found a slow and partial TMP mineralization mainly linked to the formation of a high content of hardly oxidizable N-derivatives, containing the major part of N. Up to 18 aromatic products and 19 hydroxylated derivatives were detected by LC-MS during TMP degradation by PEF-Pt. An additional SPEF-Pt experiment using a real wastewater matrix spiked with TMP attained slower TMP and DOC decays.
AB - The degradation of 20.0mgL-1 of trimethoprim (TMP), an antibiotic commonly detected in wastewaters, in an aqueous solution with 7.0gL-1 Na2SO4 was accomplished by electrochemical advanced oxidation processes (EAOPs) such as anodic oxidation with electrogenerated H2O2 (AO-H2O2), electro-Fenton (EF), photoelectro-Fenton (PEF) and solar photoelectro-Fenton (SPEF), as well as by the classical Fenton and photo-Fenton processes. All experiments were performed in a novel 2.2L lab-scale flow plant equipped with compound parabolic collectors (CPCs) and an electrochemical filter-press cell with a BDD or Pt anode and a carbon-PTFE air-diffusion cathode to electrogenerate H2O2. The effect of initial Fe2+ concentration, current density and pH on the PEF method with the BDD anode (PEF-BDD) was firstly assessed by means of TMP and dissolved organic carbon (DOC) decays, aiming to establish a treatment process using minimal iron concentration, adequate current density/H2O2 production and maximal pH. This treatment was efficiently performed using a low Fe2+ dose of 2.0mgL-1, a low current density of 5mAcm-2 and pH of 3.5 without iron precipitation. The relative oxidation ability of EAOPs using the BDD/air-diffusion cell increased in the order: AO-H2O2<EF<PEF<SPEF. The EF-BDD and PEF-BDD processes were more effective than the comparable Fenton and photo-Fenton ones. The PEF-BDD process exhibited slightly faster TMP degradation than the PEF-Pt one, whereas in SPEF the influence of the anode was almost negligible. After ca. 37kJL-1 UV energy, 77 and 73% mineralization with 30 and 26% current efficiency and 1.2 and 0.9kWhm-3 energy cost were obtained, respectively. It was found a slow and partial TMP mineralization mainly linked to the formation of a high content of hardly oxidizable N-derivatives, containing the major part of N. Up to 18 aromatic products and 19 hydroxylated derivatives were detected by LC-MS during TMP degradation by PEF-Pt. An additional SPEF-Pt experiment using a real wastewater matrix spiked with TMP attained slower TMP and DOC decays.
KW - EAOPs
KW - Oxidation products
KW - Photoelectro-Fenton
KW - Real wastewater
KW - Trimethoprim
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U2 - 10.1016/j.apcatb.2014.05.052
DO - 10.1016/j.apcatb.2014.05.052
M3 - Article
AN - SCOPUS:84904644394
VL - 160-161
SP - 492
EP - 505
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
SN - 0926-3373
IS - 1
ER -