<p>Electrochemical disinfection holds promise in meeting the needs of decentralized wastewater treatment. Magneli phase titanium sub-oxide, or Ebonex, and its use as an unmodified electrochemical disinfection electrode are studied. Anodic and cathodic potential magnitudes are shown to strongly influence Ebonex surface chemistry. By controlling and maintaining hydroxyl functionalization of the Ebonex surface, chlorine generation can be both catalyzed and maintained resulting from improved electron transfer. Granular Ebonex is then placed in a packed bed electrochemical reactor (PBER) for further study. It is found that the maximum current is reached when the bed height-to-width ratio of the working electrode compartment of the PBER is 1:6. This is shown to be due to inter-granule resistances and screening of active area. The PBER is applied to the disinfection of blackwater where static versus cycled potential methods are compared. It is found that the methods are comparable in both time and energy despite the Ebonex being operated at anodic potentials 83% of the time in the cycled method compared to the static method.</p> Graphical Abstract <p></p>