Combined use of LS-PIV and CFD for the characterization of turbulent flow in the contact chamber of ‘COSTA AZUL’ wastewater treatment plant, Carlos Paz

Abstract

Abstract The Costa Azul wastewater treatment plant is situated in Carlos Paz city (Córdoba, Argentina). The treated water is discharged to the San Roque reservoir, which is the source of water for the city of Córdoba and surrounding towns. Consequently, it is of great importance to evaluate the potential impact on the water quality reservoir for the preservation of public health. Currently, the WWTP lacks an accurate flow monitoring system at the last treatment: disinfection. This problem led to the development of a methodology in which experimental in-situ work and computational fluid dynamics (CFD) were applied, in a combined way, to calibrate the flow measurement system. First, large-scale particle image velocimetry (LS-PIV) was applied. The results made it possible to obtain characteristic parameters of the average flow: cross-sectional velocity profiles, recirculation and flow stagnation zones, flow discharge and characteristic parameters of the contact chamber. Second, numerical models, based on the Reynolds-average Navier–Stokes equations with the k–ε turbulent closure model were used. Based on the simulation results, it was possible to calibrate the discharge equation for a rectangular weir, and elaborate recommendations to improve the discharge measurement system and hydraulics in the area of the contact chamber curves.