Decolourization of anthraquinone reactive dye by electrochemical reduction on reticulated glassy carbon electrode

the electrochemistry reduction for the removal of reactive blue 4 (rb4) dye from aqueous solution using reticulated glassy carbon electrode is investigated. at ph < 8.0 the anthraquinone group of the rb4 dye are reduced in one cathodic step to hidroquinone after a reversible two-electron process involving a precedent two protons reaction. a stable semiquinone is detected by spectrophotometric technique. at ph > 8.0 the reduction process involves two reversible 2-electron steps, whose species are generated by a protonation equilibrium of anthraquinone group. the results shows that 60% of color removal was obtained after 3 hours of rb4 dye electrolysis at acidic and neutral conditions and only 37% at alkaline conditions. simultaneously 64% of total organic carbon was removed after electrolysis at ph 2.0.