Method and systems for oxygenation of water bodies

A water treatment system comprising a pump (not shown) drawing a predetermined maximum flow of water through an intake header (not shown); an oxygen contact chamber (88) operable to oxygenate water flowing therethrough to generate an oxygenated water, the pump delivering the water into the oxygen contact chamber; and a bubble capture system (84) receiving the oxygenated water from the oxygen contact chamber. The bubble capture system has a housing (93) with an outlet (95) at a lower end of the housing for releasing an outflow. The bubble capture system receives the oxygenated water from the oxygen contact chamber through an inlet riser (91) with an opening (92). The inlet riser (91) is disposed within the housing, with the opening (92) disposed adjacent a closed upper surface at the upper end of the housing. Water flow through the bubble capture system (84) is first upward, through the inlet riser (91) and out through the opening (92), followed by a downward flow toward the lower end of the housing, and then through the outlet (95). A diameter of the housing (93) of the bubble capture system (84), and the downward flow rate of the oxygenated water are selected to ensure that a downward water velocity from the opening (92) of the inlet riser (91) to the outlet (95), is slower than a bubble rise velocity of bubbles inside the housing (93). This is to ensure that the bubbles remain near a top of the housing. Bubbles in the oxygenated water are collected in an area adjacent the closed upper surface of the housing. The proposed invention can be applied to water bodies to mitigate eutrophication and may also be applicable in other fields, such as wastewater lift stations, fish farms, oil and gas industry, tidal applications with low flushing rates, and winter under ice oxygenation to prevent fish kills.