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

The oxygenation capacity in wastewater directly affects the performance of biological treatment systems. In this context, this study develops a mathematical model that describes this capacity as a function of the aeration system used. Three configurations were evaluated: fine bubble, coarse bubble, and extra coarse bubble, using experimental tests that measured dissolved oxygen concentration, saturation time, and the overall mass transfer coefficient (kLa). The resulting models achieved high fit (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 1.28 mg.L⁻¹.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.