Abstract: Water may be purified through the utilization of ultraviolet light and ozone so as to obtain some residual ozone in the water treated by passing a mixture of water and air or air and ozone through a nozzle which concurrently compresses the mixture and breaks up any gas bubbles within the mixture into what may be loosely referred to as a radiation housing or chamber. The housing is a hollow, cylindrical chamber located around an elongated tubular lamp for producing actinic light such as ultraviolet light. The mixture is introduced into this chamber in a substantially tangential manner so as to swirl around the interior chamber in passing from the inlet of the chamber where the nozzle is located to the outlet of the chamber at the other end of the chamber.