INFLUENCE OF INFLOW-OUTFLOW SYSTEMS FOR NATURAL MIXING IN A RETENTION POND

A retention pond is used to temporarily store and control stormwater runoff. The importance of a retention pond is that it reduces flood peak discharge by temporary storage and gradually release from its outlet. It is also designed with an inlet and outlet system that also produces a natural mixing inside the pond. However, there has not been any written procedure that explains which inflow and outflow orientation is the best in producing effective natural mixing.
This research is conducted to identify the influence of inflow and outflow orientation in creating an effective natural mixing inside of a circular tank which acts as a retention pond. The research uses an experiment approach by using a constant flowrate, with a variable of nine different inflow and outflow orientation. The results were compared base on Total Suspended Solid (TSS) test. From that, it was found that the lowest level of inflow (I1) and highest level of outflow (O3) gave the best result in producing effective natural mixing.