Abstract: An oxygenation apparatus for introducing a flow of oxygen gas molecules into a carrier liquid in a one-pass operation comprises a receiving chamber for receiving carrier liquid, a contacting chamber for allowing the oxygen gas molecules to thoroughly contact the carrier liquid, and a separating partition located between the receiving chamber and the contacting chamber so as to preclude the return of oxygenated carrier liquid from the contacting chamber to the receiving chamber. There is an inlet for introducing oxygen gas molecules at a pressure slightly above the ambient surrounding air pressure into the apparatus, which terminates in an end portion having a gas introduction orifice. The gas introduction orifice is located in fluid communication with the receiving chamber, and causes a jet of oxygen gas molecules to be emitted therefrom.