common aeration system in ASPs in developed countries and provide the extra benefit of keeping the solution well-mixed [11]. As such the aim of this work is the study of the volumetric oxygen
mass transfer kLa of diffused aerators in an ASP, under varying operational conditions, by measurement of the dissolved oxygen (DO). An empirical correlation for kLa versus nine studied variables (Table 1; tank volume (Vt), height (Ht), diameter (Dt) & surface area (At), airflow rate (Qa), diffusers surface area (Ad) & depth (hd), bubble size (db) and dynamic viscosity (l)) for clean water and for activated sludge in a diffused aerated cylindrical batch reactor will be created. Via the static method (ASCE [5]) the oxygen mass transfer from clean water and AS samples will be tested under equal varying operational conditions. An adapted model (based on Al-Ahmady [12] for rectangular tanks) for diffused aeration in wastewater, similar to the many existing models (although based on clean water, Table 1) will be created via the dimensionless analysis