An air-water interface generator is a proposed apparatus aiming to enhance oxygen transfer by increasing the contact area between air and water. It has been proved that this apparatus could increase the volumetric oxygen transfer coefficient in laboratory scale. Therefore, it is important to study about upscaling in order to apply this apparatus in an actual aeration tank. In this study, the apparatus was investigated for the effect of water volume and water depth on the oxygen transfer process. Referring to the experimental results, an air flow rate approximately 31.5-32.5 m3/hr per m3 of water could achieve satisfactory degrees of both oxygen transfer performance and efficiency. Moreover, an empirical model with ±40 % error was also proposed. From the model, the enhancement of volumetric oxygen transfer coefficient around 30 % could be estimated.
Keywords: Dissolved oxygen; air–water interface; diffused aeration; oxygen transfer efficiency; volumetric oxygen transfer coefficient.