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The indirect electrochemical oxidation (IEO) of Reactive Blue 19 has been studied at boron-doped diamond (BDD) and Ru 0.3 Ti 0.7 O 2 /Ti anodes by applying 25, 50 and 75 mA cm −2 in presence of NaCl as supporting electrolyte. Results clearly showed that electrochemical degradation of dye was achieved via electrogenerated species (hydroxyl radicals and active chlorine), obtaining higher removal efficiencies of color (100% for both anodes) and organic matter from solution (from 30 up to 60% for Ru 0.3 Ti 0.7 O 2 /Ti and from 65 up to 80% for BDD). In order to understand the key role of oxidants, active chlorine species were also determined, achieving different concentrations of dissolved Cl 2 , HClO, ClO − , chlorite, chlorine dioxide and chlorate at both anodes, as a consequence of experimental conditions used as well as the nature of electrode material employed. For BDD, the IEO was more effective due to the effective production of • OH radicals as well as HClO and ClO − species that favor the degradation of organic matter. The results are discussed on the light of existing literature.

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Aim of the present communication is to show experimental results, and related conclusions, on the electrochemical oxidation (EO) of tartaric acid (TA), which has been oxidized at Ti/PbO2, Ti/Pt, Pt and HBDD electrodes at different current densities in acidic media. TA complete mineralization has been achieved only at HBDD and Ti/PbO2, being higher the faradaic efficiency at the latter electrode. At Pt electrode, the electroxidation was found to be extremely slow, in acidic conditions. The experimental evidence has shown that the main factor is the interaction of the organic substrate and hydroxyl radicals with the electrode surface, during TA oxidation. In the case of the EO of oxalic acid (OA) in acidic media that was previously studied, better results were obtained at the Pt electrode, supporting the idea that the interaction of organic substrate with the electrode surface, was the main determining parameter and based on the results here reported, this idea was confirmed for TA, more complex compound than OA.