A numerical flow analysis using the concept of inflow age for oxidation pond design

•Cases of oxidation ponds have been made for analyzing the flow characteristics.•4 indices have been suggested for estimating the flow characteristics in ponds.•The computational flow simulations have been carried.•Using the indices, the flow characteristics and optimal conditions were estimated.

A numerical flow analysis for the design of an oxidation pond was conducted to investigate the optimal flow characteristics. This analysis includes the inflow rate and the shape and depth of the oxidation pond. The total area and maximum depth of the pond were 500 m2 and 3 m, respectively. We defined the retention time, retention time ratio, homogeneity index, and inflow exchange efficiency in order to choose the optimal conditions. The optimum width to length ratio and depth of the pond were found to be 1:5 and 2 m, respectively.