TY - JOUR
T1 - Advances in solar photoelectro-Fenton
T2 - Decolorization and mineralization of the Direct Yellow 4 diazo dye using an autonomous solar pre-pilot plant
AU - Garcia-Segura, Sergi
AU - Brillas, Enric
N1 - Funding Information:
The authors are grateful to the financial support from MICINN (Ministerio de Ciencia e Innovación, Spain) under the project CTQ2010-16164/BQU, co-financed with FEDER funds. S. Garcia-Segura thanks the grant awarded from MEC (Ministerio de Educación y Ciencia, Spain).
PY - 2014/9/10
Y1 - 2014/9/10
N2 - Here, an overview on the advances in solar photoelectro-Fenton (SPEF) is initially presented to show that it is the more potent electrochemical advanced oxidation process based on Fenton's reaction chemistry to remove organic pollutants from waters, due to the synergistic action of generated hydroxyl radicals and solar irradiation. As a novel advance for SPEF, an autonomous solar pre-pilot plant is proposed to make an energetically inexpensive process that can be viable at industrial level. The plant of 10 dm3 capacity contained a Pt/air-diffusion cell with 90.2 cm2 electrode area, coupled to a solar compound parabolic collectors (CPCs) photoreactor of 1.57 dm3 irradiation volume and to a solar photovoltaic panel that provides a maximum average current of 5.0 A. The oxidation ability of this plant was assessed by studying the degradation of Direct Yellow 4 (DY4) diazo dye, which involved the predominant destruction of organics by OH formed from Fenton's reaction between H2O2 generated at the cathode and added Fe2+, along with the photolysis of Fe(III)-carboxylate complexes with sunlight in the CPCs photoreactor. The effect of Fe2+ and dye contents as well as current on decolorization rate, substrate decay and mineralization rate was examined. About 96-97% mineralization was rapidly attained using 0.50 mmol dm-3 Fe2+ and up to 0.32 mmol dm-3 DY4 at 5.0 A. The DY4 decay always obeyed a pseudo-first-order kinetics. Eleven aromatic products, twenty two hydroxylated derivatives and nine short-linear carboxylic acids were identified as intermediates. The Fe(III) complexes of most acids were rapidly removed, pre-eminently photolyzed by sunlight, except those of acetic and oxamic acids that were slowly destroyed. The initial N of the dye was mainly released as NH4+ ion and its initial S was lost as SO42- ion. A plausible reaction sequence for DY4 mineralization involving all the detected products was finally proposed.
AB - Here, an overview on the advances in solar photoelectro-Fenton (SPEF) is initially presented to show that it is the more potent electrochemical advanced oxidation process based on Fenton's reaction chemistry to remove organic pollutants from waters, due to the synergistic action of generated hydroxyl radicals and solar irradiation. As a novel advance for SPEF, an autonomous solar pre-pilot plant is proposed to make an energetically inexpensive process that can be viable at industrial level. The plant of 10 dm3 capacity contained a Pt/air-diffusion cell with 90.2 cm2 electrode area, coupled to a solar compound parabolic collectors (CPCs) photoreactor of 1.57 dm3 irradiation volume and to a solar photovoltaic panel that provides a maximum average current of 5.0 A. The oxidation ability of this plant was assessed by studying the degradation of Direct Yellow 4 (DY4) diazo dye, which involved the predominant destruction of organics by OH formed from Fenton's reaction between H2O2 generated at the cathode and added Fe2+, along with the photolysis of Fe(III)-carboxylate complexes with sunlight in the CPCs photoreactor. The effect of Fe2+ and dye contents as well as current on decolorization rate, substrate decay and mineralization rate was examined. About 96-97% mineralization was rapidly attained using 0.50 mmol dm-3 Fe2+ and up to 0.32 mmol dm-3 DY4 at 5.0 A. The DY4 decay always obeyed a pseudo-first-order kinetics. Eleven aromatic products, twenty two hydroxylated derivatives and nine short-linear carboxylic acids were identified as intermediates. The Fe(III) complexes of most acids were rapidly removed, pre-eminently photolyzed by sunlight, except those of acetic and oxamic acids that were slowly destroyed. The initial N of the dye was mainly released as NH4+ ion and its initial S was lost as SO42- ion. A plausible reaction sequence for DY4 mineralization involving all the detected products was finally proposed.
KW - Direct Yellow 4
KW - Hydroxyl radical
KW - Oxidation products
KW - Solar photoelectro-Fenton
KW - Water treatment
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U2 - 10.1016/j.electacta.2014.04.009
DO - 10.1016/j.electacta.2014.04.009
M3 - Article
AN - SCOPUS:84906946806
SN - 0013-4686
VL - 140
SP - 384
EP - 395
JO - Electrochimica Acta
JF - Electrochimica Acta
ER -