It has been discovered that providing a reactor for disinfecting liquids having therein an antimicrobial-coated medium in an active and dynamic suspension allows for the passage of certain particles while preventing the passage of viable microorganisms. There is provided a reactor for disinfecting a liquid comprising a raw liquid inlet for allowing a raw liquid to enter the reactor, a disinfected liquid outlet for releasing a disinfected liquid from the reactor, and a suspension device for creating a highly dynamic suspension of the antimicrobial medium in a cross-section of the reactor through which the raw liquid passes to insure a substantially uniform, high average number of interactions between the antimicrobial medium and microorganisms present in the liquid passing through the reactor, thereby decreasing a quantity of viable microorganisms in the liquid as it passes from the inlet to the outlet.