There are comments on stabilized or aerobic oxygen in the "emergency water purification" thread. (i need to learn how to link a thread lol)
I use it at the onset of a cold, i have had great results helping me breath when i go to high altitudes. Until my body adjusts, i have trouble sleeping. i wake up gasping for breath... some aerobic oxygen in a glass of water cures that.
Be sure to use an anti oxident.
As for water purification, almost all harmful bacteria dies in the presence of oxygen. It works very much the way that hydrogen peroxide does, but not so violently.