Author(s): Ehsan Hendi, Asaad Shamseldin, Bruce Melville, Stuart Norris
Linked Author(s): Ehsan Hendi
Keywords: Sediment retention ponds, hydraulic performance, temperature differential, residence time, buoyancy driven flow.
Abstract: Sediment retention ponds (SRPs) are widely used for control of water quality and quantity. Previous studies have examined the effect on the performance of SRPs of physical parameters such as positioning and orientation of pond inlets and outlets, pond geometry, and the location and orientation of baffles. However, the effect of a temperature difference between the pond and the inflow, an environmental parameter, is often neglected. This paper reports on a study of the effect of temperature on the performance of a model SRP, using two heat exchangers to create a temperature difference between the inflow and the water in the pond. The effect of inflow temperature is investigated, for different temperature differentials. For influent colder than the pond water, the inflow tended to sink to the bottom of the pond and move rapidly towards the outlet; for influent hotter than the pond water, the inflow tended to flow on the top of the pond. The positive or negative buoyancy-driven flow significantly reduced the hydraulic performance of the pond, and it also caused severe short-circuiting. At the end of each test, the flow became stratified, illustrating the long-term effect of temperature differentials. But, however, this stratification reduces with time
Year: 2017