This study focused on the electrochemical degradation of hydrolyzed Remazol Black B (CI Reactive Black 5), a common diazo reactive dye, in aqueous solution. In the presence of various auxiliary dye chemicals, a typical Remazol Black simulated exhausted dyebath liquor was treated electrochemically in various basic electrochemical reactor configurations such as batch, batch recirculation and single pass systems. The effect of current density, supporting electrolyte concentration, electrolysis duration, specific electrode surface and fluid flow rate on pollutant removal and energy consumption performance of the systems was critically evaluated. Batch studies show the following operating parameters, current density: 2.5 A/dm 2 , electrolysis duration: 6 h, and supporting electrolyte concentration: 3 g/L, were optimal for good overall performance of the system. Color removal was complete by 3 h of treatment for all combinations of parameters studied. The pollutant removal performance of the batch recirculation system was found to have improved considerably by increasing the flow rate. Performance of the batch recirculation system was comparatively better than the other rector configurations studied, with respect to capacity utilization and energy consumption.