Hydraulic Modeling for Waste Stabilization Ponds

Treatment performance of waste stabilization ponds is a function of both the hydraulic transport and the biological and chemical transformation processes within the pond. Both the efficient hydraulic design of these ponds and the appropriate mathematical models for describing the hydraulic transport process are identified. A model consisting of a dispersed flow active zone and a fully-mixed return flow zone is developed and calibrated. Dye tracer studies and model simulations are utilized to illustrate the treatment efficiency of various pond geometries and inlet and outlet configurations. Recommendations are made for optimum design. For certain of the ponds analyzed, treatment efficiency predicted by the completely-mixed flow model compares well with that determined by analysis of dye tracer studies. The plug flow assumption seriously overestimates treatment efficiency.