Electrochemical removal of CI Acid orange 10 from aqueous solutions

The removal of CI Acid orange 10 from aqueous solutions was studied by electrocoagulation and electrooxidation techniques. For electrocoagulation, metallic iron was used as electrodes whereas graphite and IrO2/TaO2/RuO2 coated titanium were used in the case of electrooxidation. During electro-coagulation, the CI Acid orange 10 molecule was split into aniline and 1-amino-2-naphthol-6,8-disulfonic acid due to reductive cleavage of azo bond. The latter was found to co-precipitate with iron oxy-hydroxide whereas aniline remained in aqueous phase. The zeta-potential measurements and FT-IR spectroscopic studies have revealed the chemical interaction between 1-amino-2-naphthol-6,8-disulfonic acid and iron oxy-hydroxide which formed as a result of anodic dissolution. De-colorization and degradation of the dye was followed using UV–Vis spectroscopy, GC–MS and TOC measurements. The CI Acid orange 10 was completely oxidized and removed with graphite electrodes. However the oxidation was only partial with IrO2/TaO2/RuO2 coated titanium electrodes. The effect of initial pH and current density on the removal of CI Acid orange 10 was discussed.