Application of CFD methods to the upgrading of a contact tank

The paper presents the results of a Computational Fluid Dynamics (CFD) study undertaken to upgrading the hydraulic efficiency of the contact tank of the wastewater treatment plant of Nola-Marigliano, near Napoli. First numerical simulations were performed to compare the hydraulic performances of two existing operating schemes (A and B). The results pointed out the presence of recirculation areas near the baffles and the corners of the tank. Second some different changes were proposed for scheme A, which has shown the best performances, to reduce dead-zones inside the tank. Hence, further numerical simulations pointed out that the introduction of a grid inside the internal walls of the tank allowed to improve its hydraulic performance. Overall, the study demonstrated that CFD methods could be applied to improve the hydraulic performances of existing contact tanks.