Oxygen versus Air
Ozone generators can either utilize oxygen or air as the feed gas. The ozone manufacturers have optimized their corona discharge dielectric to maximize ozone output while minimizing equipment cost and ensuring reliability. Some of the ozone manufacturers design their units to specifically operate on oxygen. Others allow either feed-gas be used although clearly specify different operating parameters to ensure equipment reliability.
It has been a trend over the past 10 years to produce ozone with oxygen. Switching to oxygen as the feed gas lowered ozone production energy (cost) in half. There are also numerous other advantages of going to oxygen as the feed gas (maintenance on dielectric, double performance output, and significant increase in ozone concentration (6-10% wt). There are also disadvantages from the application standpoint: oxygen gas requirement (storage, cost, safety), excess dissolved oxygen gas saturation, and dealing with the high concentration of ozone (reaction kinetics).
Do your homework and your application will direct which feed gas is best to use. Or ask OWS to assist.