Abstract 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