Abstract

Abstract: Aeration is the process by which the area of contact between water and air is increased, either by natural methods or by mechanical devices. Proper aeration can make considerable improvements in a pond ecosystem. This paper investigates pond aeration by two phase flow systems such as high head gated conduit flow systems and two phase pipe flow systems using venturi tubes. When the gate of a high head outlet conduit is partly opened or a minimal amount of differential pressure exists between the inlet and outlet sides of the venturi tube, air suction occurs at air vents. In two phase flow systems, air that is entrained into the water will be momentarily forced downstream in the form of small air bubbles. The dissolution of oxygen into the water results from the air suction downstream of high head gated conduit and venturi tube, and the rising air bubbles into pond. Moreover, high pressure in two phase flow systems also facilitates the dissolution of oxygen into the water. Therefore, two phase flow systems have an extremely high efficiency for transferring oxygen from air bubbles to water. It was observed from the results that two phase flow systems were more efficient in deep ponds than in shallow ponds.