NASA uses a form of Ionic Silver to disinfect the water system on board spacecraft. They decided to test silver in ionic form after finding that “Microbial growth is common on wetted surfaces in spacecraft environmental control and life support systems despite the use of chemical and physical disinfection methods.”
As a result of research, they now use silver as they found that both the silver ions in water and on metal surfaces were effective in controlling bacterial growth:
silver is an effective antimicrobial through multiple pathways. … the results indicate that 0.4 mg/L ionic silver is an effective biocide against many bacteria and that a pre-passivation of metal surfaces with silver can provide additional microbial control
“Disinfection of Spacecraft Potable Water Systems by Passivation with Ionic Silver” was posted on their website in 2011.