naa a22 4500 510748732 CHVBK 20180411083056.0 cr unu---uuuuu 180411e20130101xx s 000 0 eng 10.1007/s11270-012-1385-0 doi (NATIONALLICENCE)springer-10.1007/s11270-012-1385-0 Electrochemical Reduction Prior to Electro-Fenton Oxidation of Azo Dyes: Impact of the Pretreatment on Biodegradability [Elektronische Daten] [F. Fourcade, M. Delawarde, L. Guihard, S. Nicolas, A. Amrane] The aim of this work was to study the degradation of three azo dyes, Orange II, Methyl red and Biebrich Scarlet by electro-Fenton and the effect of the electrochemical pretreatment on the biodegradability of the solutions. The electrochemical pretreatment showed that an electrochemical reduction on the carbon felt electrode was mainly responsible for the decolorization of the azo dyes. Indeed, the electrochemical behaviour of the azo dyes highlighted their electroactivity; electrolysis with and without ferric ions led to the same decolorization yield, namely 99% at 15min for Methyl red, and stable chemical oxygen demand (COD) values were recorded during decolorization. In a second step and owing to the absence of by-product electroactivity in reduction, the formation of hydroxyl radicals by the Fenton reaction led to the oxidation of by-products from the electrochemical reduction. It was illustrated by the decrease recorded for the COD values. The results also showed that the azo bond cleavage occurring during the electrochemical reduction was not sufficient to significantly reduce recalcitrance, as shown from biological oxygen demand (BOD)5/COD ratio examination below the limit of biodegradability (0.4). Contrarily, a positive trend was recorded for Orange II during the electro-Fenton reaction, with a BOD5/COD ratio of 0.81 after 28h of pretreatment. Springer Science+Business Media Dordrecht, 2013 Electro-Fenton nationallicence Electrochemical reduction nationallicence Azo dye nationallicence Biodegradability nationallicence Fourcade F. Université de Rennes 1, CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35708, Rennes Cedex 7, France aut Delawarde M. Université de Rennes 1, CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35708, Rennes Cedex 7, France aut Guihard L. Département Chimie, IUT de Rennes, Université de Rennes 1, 3 rue du Clos Courtel, BP 1144, 35014, Rennes Cedex, France aut Nicolas S. Département Chimie, IUT de Rennes, Université de Rennes 1, 3 rue du Clos Courtel, BP 1144, 35014, Rennes Cedex, France aut Amrane A. Université de Rennes 1, CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35708, Rennes Cedex 7, France aut Water, Air, & Soil Pollution Springer Netherlands 224/1(2013-01-01), 1-11 0049-6979 224:1<1 2013 224 11270 https://doi.org/10.1007/s11270-012-1385-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11270-012-1385-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fourcade F. Université de Rennes 1, CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35708, Rennes Cedex 7, France aut NATIONALLICENCE 700 1- Delawarde M. Université de Rennes 1, CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35708, Rennes Cedex 7, France aut NATIONALLICENCE 700 1- Guihard L. Département Chimie, IUT de Rennes, Université de Rennes 1, 3 rue du Clos Courtel, BP 1144, 35014, Rennes Cedex, France aut NATIONALLICENCE 700 1- Nicolas S. Département Chimie, IUT de Rennes, Université de Rennes 1, 3 rue du Clos Courtel, BP 1144, 35014, Rennes Cedex, France aut NATIONALLICENCE 700 1- Amrane A. Université de Rennes 1, CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35708, Rennes Cedex 7, France aut NATIONALLICENCE 773 0- Water, Air, & Soil Pollution Springer Netherlands 224/1(2013-01-01), 1-11 0049-6979 224:1<1 2013 224 11270 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer