Application of Photoelectro-Fenton/BDD Process Based on the Cathodic Production of H2O2 for Degradation of Industrial Dyes

Wednesday, 8 October 2014: 09:00
Sunrise, 2nd Floor, Galactic Ballroom 4 (Moon Palace Resort)
J. M. Peralta Hernandez and A. cruz-Rizo (CIATEC)
Photoelectro-Fenton/BDD process promotes in situ hydrogen peroxide (H2O2) by means of oxygen reduction via two electrons, adding Fe2+ to the solution resulting in the production of free hydroxyl radicals (OH). The reaction can be catalyzed by the UV ligth accelerating the degradation of organic compounds in solution, because it promotes the photocehmical regeneration of Fe2+, and as a result a major OH radicals production. In the present work, the authors discussed the study of the H2O2 production over boron doped diamond (BDD) cathode and the degradation of two industrial azo dyes, Blue-BR (B-BR) and Black-TRS (B-TRS) by photoelectro-Fenton/BDD (PEF/BDD) process using UV-ligth source. Comparative electrolyses carried out with 3L filter press pilot plant equipped with a BDD anode and cathode at constant current density showed the superiority of the processes with BDD because of the higher oxidation ability of ·OH formed from water oxidation at the BDD surface. Total mineralization was rapidly reached for the most potent treatment of PEF with BDD due to the additional oxidation by ·OH produced from Fenton's type reaction between added Fe2+ (0.5mM) and H2O2 generated at the cathode. Azo dyes decay always followed a pseudo-first-order kinetics. The influence of current density and substrate concentration on PEF with BDD was examined.