The oxygenation column are designed to optimize the saturation of gases in water, and can obtain gas transfer efficiencies of up to 100%. The operation of the cone is simple: water and gas (either pure oxygen, ozone or other gas) enter from the top where the velocity is reduced as the body of the vessel expands. As the water moves to the bottom of the vessel the gas rises to the top and is constantly sheared. The undissolved gas keeps returning to the top, and when adjusted properly, only water without bubbles can exit the bottom. At higher pressures, the dissolved oxygen concentration could be increased significantly above saturation.