This started with NASA and potable water in spacecraft.
It's seen much more application, though, in fountains and swimming pools to stomp on algae. Usually, a mix of Cu and Ag is used. I would research the effects of ingesting Cu and Ag. A couple decades ago, I did some design work on this kind of ion generator for pools. It used a copper plug with a drilled center section that contained silver. It is very easy to send in a ion stream; more work to control the amount of it in a variable amount of drinking water.