Decoloration of Azo Dyes by Hydrogen Peroxide Catalyzed by Water-Soluble Manganese Porphyrins

Abstract

Water-soluble manganese porphyrins are catalysts for the decoloration of azo dyes by hydrogen peroxide under mild conditions (pH 8.0 and 25°C). The decoloration rate depends on the structure of the manganese porphyrin and the added ligands.

Effect of a non-ionic surfactant, Merpol, on dye decolorization of Reactive blue 19 by laccase

“…Although Reactive blue 19 most likely bears a net negative charge at pH 5, hydrophobic interactions with Merpol may be dominant. This may partially explain our results and is supported by Tokuda et al [21] who has shown that both electrostatic and hydrophobic interactions affected decolorization rates by peroxide bleaching agents in the presence of surfactant molecules.…”

“…This is significant since surfactants are common in dye effluents and can affect not only biological decolorization (whether enzymatic or with a fungal culture) but also physical or chemical decolorization processes [21]. The efficiency of the process will most likely diminish with the degree of interaction between the dye and the surfactant and the quantity of the surfactant.…”

Indium tin oxide coated conducting glass electrode for electrochemical destruction of textile colorants

“…Over the past few years, alternative methods for dye treatment have been investigated, including chemical oxidation with reagents such as: ozone, hydrogen peroxide, ozone/UV, hydrogen peroxide/UV and Fenton's reagent [6][7][8][9][10]. Other alternative techniques such as biological treatment [11][12][13], adsorption and precipitation [14][15][16] and reductive treatment [17][18][19] have applied successfully. For all the proposed techniques, great care has to be taken to keep the costs of such processes at reasonable levels and to avoid the formation of byproducts, which cause additional costs for secondary treatment or disposal.…”

Kinetics of the oxidative degradation of thionine dye by hydrogen peroxide catalyzed by supported transition metal ions complexes

“…H 2 O 2 itself is a moderate oxidizing agent towards most organic substrates. Activation of hydrogen peroxide by transition metal complexes for the oxidation of organic substrates has been extensively studied 30–36. The heterogeneous activation of H 2 O 2 eliminated the addition of soluble catalysts and may offer a great flexibility in terms of reaction rate.…”