Hydrologie : recherche actuelle

The Effect of Hydraulic Jump on the Performance of Waste Stabilization Ponds

Abstract

Agunwamba J C and Ogarekpe N M

One of the simplest forms of biological treatment processes used in the tropics is the waste stabilization pond (WSP). The relative simplicity and low operating cost of the WSP make it the preferred technology for handling, treatment and disposal of municipal waste for small communities. However, its use in urban areas is limited because of its large area requirement. Hence, the research is aimed at investigating if the introduction of hydraulic jump in the Waste Stabilization Pond can increase treatment efficiency and consequently reduce the land area requirement. Thus, WSPs with varying number of hydraulic jumps were constructed using metallic tanks. The hydraulic jumps were created to introduce turbulence thereby adding dissolved oxygen in the pond. Wastewater samples collected from different points (including inlets and outlets) in the ponds were examined for physio-chemical and biological characteristics for a period of ten weeks. The parameters examined were dissolved oxygen, coliform, biochemical oxygen demand (BOD5), chemical oxygen demand and tracer studies. The efficiencies of the WSPs with respect to these parameters fluctuated with variations in the atmospheric conditions and varying discharge with the highest efficiency obtained from the pond with two hydraulic jumps. The research revealed that the cost of wastewater treatment using hydraulic jump enabled WSP was approximately one and a half times lower than the conventional WSP for the same efficiencies.