管内曝気によるDO改善の試み

抄録

This paper gives the results of the laboratory experiments on the DO improvement technique for natural water bodies such as lake or sea. This technique forms bubble cluster on the water surface in a h- shaped pipe by aerating water to be treated introduced into the pipe. The bubble cluster has a high rate of gas exchange between gas and liquid phases due to the high gradient of DO concentration in the liquid phase of the water film of a bubble. Performance of the device has been investigated by the quantity of oxygen dissolution flux evaluated by the product of the equivalent DO increment and the rate of the water treatment, and the ratio of this flux to the power required for aeration. Present experiment showed that the good condition for oxygen dissolution is accomplished at some optimum flow rate of air for aeration, that the elevation of the horizontal part of h-shaped pipe above the outer water surface should be as low as possible, and that the energy efficiency becomes high as the flow rate of air is low.