Keywords: aromatic sulphonic acids, wastewater treatment, boron-doped diamond electrode, electrochemical oxidation, cyclic voltammetry, bulk electrolysis, mineralisation
Electrochemical oxidation of aromatic sulphonated acids on a boron-doped diamond electrode
The electrochemical oxidation of an industrial wastewater containing aromatic sulphonated acids on a boron-doped diamond electrode (BDD) was studied using cyclic voltammetry and bulk electrolysis. The influence of the current density and flow-rate was investigated in order to find the optimum conditions. It was found that a polymeric film, which caused BDD deactivation, was formed in the potential region of water stability during oxidation, however it was removed by high-potential anodic polarisation in the region of O2 evolution. The complete mineralisation of the wastewater was achieved over the whole range of experimental conditions examined, due to the production of hydroxyl radicals on the diamond surface. The oxidation of the aromatic sulphonated acids was favoured by a low current density and a high flow-rate meaning that the oxidation was a diffusion-controlled process.