Distillery Wastewater Treated by Electrochemical Oxidation with Boron-Doped Diamond Electrodes

Electrochemical oxidation of pretreated distillery wastewater was performed using a boron doped diamond anode (BDD). The role of direct oxidation of organic matter was assessed with experiments of linear sweep voltammetry, noting that the deactivation of the electrode surface occurs in the region of potentials below oxygen evolution. Then, galvanostatic bulk electrolyses were conducted during 4 hours at current densities (20 mAcm(-2), 30 mAcm(-2) and 40 mAcm(-2)) corresponding to high anodic potentials, in a single compartment flow cell in a re-circulated batch process. Two different flow rates were evaluated, finding that the process was controlled by the mass transport of organics towards the anode. Initial pH variation did not significantly affect the oxidation process. Analyses of the treated samples were carried out by UV spectroscopy, Pt-Co color, COD and TOC. The degradation of organic compounds measured as TOC was up to 81%; 88% COD removal efficiencies and 98% color removal were also obtained.