CFD Design of an Outlet Diffuser to Improve Circulation in Wastewater Treatment Pools

Abstract

Algae proliferation in wastewater treatment pools is often associated with poor circulation, which promotes the formation of dead zones. This phenomenon not only reduces the efficiency of the system but also reinforces algae growth by creating stagnant conditions favorable to its development. With the aim of optimizing the operation of the wastewater treatment system in a process plant, the design of an outlet diffuser was evaluated using Computational Fluid Dynamics (CFD) tools to promote a uniform flow distribution within the pool. Three different outlet diffuser geometries were analyzed using ANSYS Fluent under steady-state flow conditions. The study identified a configuration that significantly improves flow uniformity at the outlet section, thereby helping to mitigate the formation of stagnant zones and, consequently, reducing conditions favorable to algae proliferation. Although uniformity at the outlet does not guarantee optimal hydraulic behavior throughout the entire pool—since this also depends on the inlet diffuser and the overall geometry of the system—the results represent a step forward in enhancing the overall efficiency of the treatment system.