A modular waste disinfection system for the disinfection of substantially liquid infectious waste streams and methods of treating such waste streams are disclosed. The modular waste disinfection system includes a metal ion generation chamber for introducing metal ions into the waste material; an oxidant generation chamber in fluid flow communication with the metal ion generation chamber for disinfection of the waste material with an oxidizing agent; and a chelation chamber in fluid flow communication with the oxidant generation chamber for deactivation of metal ions in the waste material, wherein the waste is discharged to a sanitary sewer after disinfection.