Electrochemical degradation of the reactive red 141 dye on a β-PbO2 anode assessed by the response surface methodology

Abstract

A degradação eletroquímica do corante Vermelho Reativo 141 foi investigada por meio da aplicação da metodologia de superfície de respostas, utilizando reator filtro-prensa com anodo de β-PbO 2 . A carga requerida para 90% de descoloração (Q 90 The electrochemical degradation of the Reactive Red 141 dye using a filter-press reactor with a β-PbO 2 anode was investigated through the application of the response surface methodology. The charge required for 90% decolorization (Q 90 ) and the chemical oxygen demand removal percentage after 30 min electrolysis (COD 30 ) were used to model the system. The investigated independent variables were the current density, pH, NaCl concentration, and temperature. Low ), when Cl 2 and HOCl are the predominant oxidant species. The best values of COD 30 were obtained at high current densities and acidic to neutral conditions (pH 5-7); however, the consequent energy consumption makes the process not economically feasible under these conditions. For strongly acidic solutions, specific energy consumptions associated to Q 90 as low as 0.79 kW h m -3 were attained.

Synthesis and characterization of new Ti–Bi2O3 anode and its use for reactive dye degradation

“…and their mixtures. All the above mentioned materials have a high surface area and excellent mechanical and chemical resistance even at high current densities [12][13][14][15][16][17][18].…”

A comparison of electrodeposited Ti/β-PbO2 and Ti-Pt/β-PbO2 anodes in the electrochemical degradation of the direct yellow 86 dye

“…22 Thus, different pH conditions were reported as the best ones for color and organic removals. 6,18,23 The possible formation of undesirable chloro-organic derivatives is a known drawback of electrooxidation processes in chloride-containing solutions, although very few papers have actually reported these compounds. 24 Undesirable inorganic compounds, such as ClO 4 -ions, which are mainly formed in electrooxidations using BDD anodes, also represent serious health problems.…”

“…25 PbO 2 film anodes are interesting materials for the electrochemical degradation of pollutants due to their medium to high oxidation power, easiness of preparation, and low cost. [12][13][14]23 The PbO 2 film electrochemical performance and stabilization are influenced by the presence of doping species, 12,13,26 electrodeposition conditions, 26,27 and substrate preparation. The main concern when using PbO 2 anodes is the possible release of toxic Pb 2+ ions and problems related to the adherence of the oxide film to the substrate that reduce the lifetime of the anodes.…”

Eletrochemical Oxidation of Herbicides

“…For DSA-like anodes, the •OH radicals strongly bind to the surface, eventually leading to the indirect oxidation of organics via formation/decomposition of an oxide of higher valence (De Oliveira et al, 2008). In order to increase the oxidation rate of DSA-kind materials, different approaches have been proposed in the literature, such as the use of PbO 2 (Cestarolli & De Andrade, 2003;Aquino et al, 2010;Panizza et al, 2008a) and BDD (Panizza et al, 2008b), and changes in the supporting electrolyte (Aquino Neto & De Andrade, 2009b).…”