The effect of surfactant as the organic component of the simulated wastewater on aluminium as electrode material was studied. The characterisation of electrode material referred to various solutions (low sodium chloride concentration, sodium sulphate and anionic, cationic and non-ionic surfactants) and conditions of pH. The overall anodic and cathodic processes were studied by voltammetric techniques in potentiostatic and galvanostatic variants. The scan rate ranged between 0.02-200 V/s and 0.0001-0.01 A/s, respectively. The electrode processes could be stimulated or inhibited depending on scan rate, history of the electrode, pH and surfactant type. The change of the anodic inhibition or activation was interpreted by the character of superficial oxide film and partially defilming process. Such aspects correlated to some extent with the electrode activity in electrocoagulation. The simulated water treatment was carried out in an electrocoagulation cell in galvanostatic conditions. The efficiencies of treatment ranged between 40 and 60% as chemical oxygen demand (COD) removal. (C) 2000 Elsevier Science Ltd. All rights reserved.