Parameters Affecting Hydraulic Behavior of Aerated Lagoons

Tracer studies were performed at the full-scale St-Hermas aerated lagoon, Quebec, Canada, and a dynamically similar laboratory model to determine the effects of the water flow rate and aeration rate on hydraulic mixing. The tracer study E-curves were extrapolated to ensure conservation of the tracer mass within the system and in turn were analyzed using a two-celled compartmental model. The results of the compartmental model analysis demonstrate that the water flow and aeration rates both influence the percentage of dead zones and bypassing within the system, with the water flow rate being the dominant parameter. This study therefore concludes that hydraulic mixing of aerated lagoons is significantly affected by the water flow and aeration rates. The ability to demonstrate that these hydraulic parameters affect the mixing of aerated lagoons is attributed to the E-curve development and the compartmental model analysis used in this study.