Factors affecting fine bubble creation and bubble size for activated sludge

This paper addresses a study of air bubble creation in wastewater treatment system using both computational fluid dynamic (CFD) and experimental techniques. Based on the results found in this work, it was found that the bubble size depends on several factors such as flow rate, inlet pressure and contact angle for rubber membrane. Among these factors, it was found that the flow rate has the largest effect on the bubble size followed by membrane material contact angle. The punch size has a moderate effect on the bubble size while the punch length and punch direction have slight effect on bubble size. Finer bubbles are desired and they provide larger surface area and longer residency time which will improve the standard oxygen transfer.