Performance Assessment of Venturi-Assisted Confined Tube Aerators with Varying Diameter

Abstract

A significant amount of energy in wastewater treatment plants is spent on aeration to treat the organic matter with microorganisms in an oxygen-enriched environment. In this study, a novel and simplistic aeration concept known as Confined Tube Aeration (CTA) is proposed, in which the main elements are a Venturi injector and a coiled tube at its outlet. Two Venturi injector diameters were chosen for evaluation in this study, measuring 1 inch (25.4 mm) and 4 inch (101.6 mm). In this study, a relationship was developed between air suction rate and pressure differential across the injector. Then, a numerical model was developed to analyze hydrodynamic conditions and evaluate system performance. The main findings are that the larger diameter aerator performs 20% better than the smaller injector in terms of standard aeration efficiency (SAE), with a maximal value of 0.74 kgO2/kWh found for the larger diameter system. These results suggest that future SAE improvements may be made for larger diameter systems in full-scale wastewater treatment applications with suitably designed injectors.