Effect of Varying Discharge Rate on the Performance of Venturi Aeration System

Abstract

Venturi aeration is an economical method to increase dissolved oxygen (DO) in aquatic water bodies. For this paper, aeration experiments were conducted with 200 litres volume of the water tank, having dimensions of 90 cm length, 55 cm breadth, and 45 cm depth. The venturi was fabricated keeping the dimension of converging and diverging length same, i.e., 76 mm and throat length of 100 mm. The venturi aeration system was operated with six different discharge rates (0.00025, 0.00033, 0.00042, 0.00050, 0.00058 and 0.00067 m3/s). This work is intended to estimate the effect of varying discharges on the efficiency of venturi aerator in terms of standard oxygen transfer rate (SOTR) and standard aeration efficiency (SAE). The experiment shows promising results in terms of SOTR and SAE at moderate to high discharge rates, on the other hand a declining trend is seen when the liquid discharge rate is too high. The oxygen transfer rate was found to have a good relationship with the discharge rate.