Mathematical Modeling of Oxygenation Capacity in Wastewater Based on Air Diffuser Type

Abstract

The oxygenation capacity in wastewater directly impacts the performance of biological treatment systems. In this context, this study develops a mathematical model describing this capacity as a function of the aeration system used. Three configurations were evaluated: fine bubble, coarse bubble, and extra coarse bubble, through experimental tests measuring dissolved oxygen concentration, saturation time, and the overall mass transfer coefficient (kLa). The data generated models with high fit levels (R² between 0.9988 and 1), supporting their validity in representing the observed behavior. The fine bubble system showed the highest initial oxygenation capacity, reaching a rate of 1.28 mg/L·s⁻¹, though it decreased significantly over time by 96.09%. Overall, the results quantitatively characterize the dynamics of each diffuser type, providing relevant technical criteria for the design and selection of wastewater treatment systems.