Article

Electro-Fenton degradation of synthetic dye mixture: influence of intermediates. J Environ Eng Manage

J. Environ. Eng. Manage 01/2009; 19:277-282.

ABSTRACT

Electro-Fenton process is a potentially useful oxidation process for destroying toxic organic compounds in aqueous medium. In this study, the electro-Fenton degradation of a solution mixture of Malachite Green (MG) and Orange II catalyzed by ferric ions was examined. Results showed that this system could degrade and mineralize the dye mixture. It was shown that absorbance decrease in MG was accelerated in the presence of Orange II, whereas absorbance decrease of Orange II at the same conditions was depressed. This behavior was attributed to generation of hydroquinone-like intermediates from degradation of Orange II that can accelerate Fenton reaction by reduction of Fe 3+ to Fe 2+ ions. GC-MS detection of the products formed in the Orange II electro-Fenton degradation showed the generation of dihydroxynaphthalene compounds that are probably responsible for acceleration of MG degradation.

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Available from: Vahid Vatanpour
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    • "dye wastewater include adsorption [6] chlorination and ozonation [7] [8], electrochemical methods [9] [10], biological methods [11] [12], and chemical oxidation [12] [13]. However, because of high dye concentrations and the increased stability of synthetic dyes, these methods are becoming less effective for the treatment of colored industry effluents. "
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    • "Rao et al.[48]reported a small effect of cathodes like Al, Cu, Pt and Zn on the decolorization and COD removal of Malachite Green by AO with a Pt anode, indicating its poor electroreduction ability. Better results were obtained by EF with Pt/graphite-felt tank reactors[18,19]. Oturan et al.[19]found total decolorization in 22 min and 95% COD abatement in 420 min when 250 cm 3 of 0.5 mmol dm À3 Malachite Green in 0.05 mol dm À3 Na 2 SO 4 with 0.2 mM Fe 3+ were electrolyzed at pH 3.0 and 200 mA. "
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