Boron Doped Diamond (BDD) thin films have recently received great attention, as they possess several technologically important characteristics including an inert surface with low adsorption properties, remarkable corrosion stability, even in strongly acidic media, and extremely high O2 evolution overvoltage. Owing to these properties, they are excellent materials for Electrochemical Oxidation (EO) processes [1]. BDD anodes have been defined as non-active electrodes, since it is expected that they do not provide any catalytically active site for the adsorption of reactants and/or products in aqueous media. Hydroxyl radicals (BDD(•OH)) formed from water oxidation are then considered the responsible species for the electrochemical combustion of organic pollutants, although slower reactions with other Reactive Oxygen Species (H2O2 and O3) and weaker electrogenerated oxidants (peroxo-disulphate, peroxodicarbonate or peroxodiphosphate) are also feasible [2]. According to the Comninellis’ model [3], the most important factor determining the extent of organic pollutants mineralization in EO is the anode material. In this light, a high number of electrodes has been tested, including graphite, Ti/Pt, Pt, PbO2 and mixed metal oxides of Ti, Ru, Ir, Sn and Sb; however, synthetic BDD thin films are currently preferred as anode material due to its better oxidative performance. Many research groups have demonstrated that the use of BDD thin films in EO provides total mineralization with high current efficiency for different organics in real and synthetic wastewaters [2]. In recent years, the interest for removing pollutants from textile wastewaters has increased, and the use of BDD films deposited on several supports has been also extended to dyestuff treatment. Effluents of a large variety of industries usually contain important quantities of synthetic organic dyes. The discharge of these colored compounds in the environment may cause considerable non-aesthetic pollution and serious health-risk factors. Since conventional wastewater treatment plants cannot degrade the majority of these pollutants, powerful methods for the decontamination of dyes wastewaters have received increasing attention over the past decade. This communication will present an overview of efficient electrochemical BDD technologies developed to decolorize and/or degrade dyeing effluents and other organic pollutants for environmental protection. [1] S. Ferro, J. Mat. Chem. 2002, 12, 2843-2855. [2] C. A. Martinez-Huitle, S. Ferro, Chem. Soc. Rev., 35 (2006) 1324-1340. [3] Ch. Comninellis, Electrochim. Acta., 39 (1994) 1857-1861.
Application of BDD electrodes for electrochemical oxidation of organic pollutants for the wastewater treatment
MARTINEZ, Carlos Alberto;FERRO, Sergio
2010
Abstract
Boron Doped Diamond (BDD) thin films have recently received great attention, as they possess several technologically important characteristics including an inert surface with low adsorption properties, remarkable corrosion stability, even in strongly acidic media, and extremely high O2 evolution overvoltage. Owing to these properties, they are excellent materials for Electrochemical Oxidation (EO) processes [1]. BDD anodes have been defined as non-active electrodes, since it is expected that they do not provide any catalytically active site for the adsorption of reactants and/or products in aqueous media. Hydroxyl radicals (BDD(•OH)) formed from water oxidation are then considered the responsible species for the electrochemical combustion of organic pollutants, although slower reactions with other Reactive Oxygen Species (H2O2 and O3) and weaker electrogenerated oxidants (peroxo-disulphate, peroxodicarbonate or peroxodiphosphate) are also feasible [2]. According to the Comninellis’ model [3], the most important factor determining the extent of organic pollutants mineralization in EO is the anode material. In this light, a high number of electrodes has been tested, including graphite, Ti/Pt, Pt, PbO2 and mixed metal oxides of Ti, Ru, Ir, Sn and Sb; however, synthetic BDD thin films are currently preferred as anode material due to its better oxidative performance. Many research groups have demonstrated that the use of BDD thin films in EO provides total mineralization with high current efficiency for different organics in real and synthetic wastewaters [2]. In recent years, the interest for removing pollutants from textile wastewaters has increased, and the use of BDD films deposited on several supports has been also extended to dyestuff treatment. Effluents of a large variety of industries usually contain important quantities of synthetic organic dyes. The discharge of these colored compounds in the environment may cause considerable non-aesthetic pollution and serious health-risk factors. Since conventional wastewater treatment plants cannot degrade the majority of these pollutants, powerful methods for the decontamination of dyes wastewaters have received increasing attention over the past decade. This communication will present an overview of efficient electrochemical BDD technologies developed to decolorize and/or degrade dyeing effluents and other organic pollutants for environmental protection. [1] S. Ferro, J. Mat. Chem. 2002, 12, 2843-2855. [2] C. A. Martinez-Huitle, S. Ferro, Chem. Soc. Rev., 35 (2006) 1324-1340. [3] Ch. Comninellis, Electrochim. Acta., 39 (1994) 1857-1861.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
