Optimization of oxygen transfer coefficient and standard aeration efficiency of a Venturi-type aerator using response surface methodology

This research focuses on determining the optimal parameters for maximizing dissolved oxygen (DO) when using a Venturi-type aerator, considering two objectives: oxygen transfer coefficient corrected to 20°C (KLa20) and standard aeration efficiency (SAE). The determination of the optimal parameters for the Venturi-type aerator was carried out under thirty experimental conditions of a face-centered central composite design (FCCD), involving four influencing variables: Venturi convergence angle (α), Venturi divergence angle (β), water flow rate (Qw), and air flow rate (Qa). Response surface methodology (RSM) was used to evaluate the experimentally collected data. The analysis of the experimental results showed that the most suitable conditions for were 45° convergence angles and 15° divergence angles, with a water flow rate of 40 L/min and an air flow rate of 0.9 L/min, resulting in a value of 4.278 h-1. For optimal SAE values, the study found that the Venturi convergence angle of 45°, the Venturi divergence angle of 15°, the water flow rate of 20 L/min, and the air flow rate of 0.9 L/min should be set. These parameters gave an SAE value of 0.0343 kgO2/kWh. Analysis of the regression equations developed in this study showed that the coefficients of determination (R2) of the KLa20 and SAE prediction equations were more than 90% for both equations. Therefore, the response can be accurately predicted, and these equations serve as guidelines for the design of the most appropriate Venturi-type aerator in practice.