It is common practice to purify water for industrial and domestic use by subjecting it to treatment with ozonized air. By “ozonized air” is meant air in which a small quantity, for example, 1 to 2 percent of ozone is incorporated. Among the advantages of water purification by means of an ozone are the fact that no harmful end products or by-products result. Also, an ozonizing system lends itself to an automatic, cyclic treatment. It is an object of the present invention to provide improvements in ozonizing systems and water purification systems employing ozone. It will therefore be apparent that a novel and advantageous apparatus, system and method for ozonizing air and for treating water with ozonized air have been provided.