Effect of aeration on oxygen transfer characteristics in integrated wastewater treatment systems utilizing mass transfer model and computation fluid dynamics methods

This paper investigates the aeration and oxygen transfer characteristics within the aeration tank of an integrated wastewater treatment system (IWTS) using Computational Fluid Dynamics coupled with Population Balance Model and oxygen transfer model. The findings suggest that increasing the air flow rate significantly enhances the oxygen transfer rate, albeit at a decreasing rate of growth. The oxygen overall mass transfer coefficient is primarily influenced by the interfacial area per unit volume and to a lesser by the oxygen mass transfer coefficient (kL). A strong positive correlation is found between turbulence intensity and kL, which, along with dissolved oxygen distribution, confirms the critical role of turbulence in the oxygen transfer process. For small-scale IWTS, an air flow rate of 30 L/min may be the optimal choice.