With a little creativity and a fan, a water ozonator can become an ozone air purifier. While the ozonator is ozonating water simply have a fan blow the excess ozone coming off the water around the house. The water ozonator can also be used while not ozonating water to purify room air the same way. If you place the output tube near a cold air return of an HVAC system, the ozone will be carried throughout the house and clean the ducts in the process.
If you're going to use a water purifier for the purpose of air purification, make sure you get one with a good air pump. The air pump is usually the first thing to fail in cheap ozonators.
Hope this helps.