Abstract

Sediment Oxygen Demand (SOD) is the key parameter for water quality analysis and water quality numerical simulations in waters such as estuaries, bays, rivers and lakes. The SOD rate can be measured in laboratory and in situ, but the in situ technique appears to be the better approach for measuring SOD as it may be the most accurate method. In order to design the SOD measurement chamber suitably, the authors numerically simulated the three-dimensional flow in the cylindrical SOD measurement chambers, which in situ measurement commonly used, by using RNG-based k-e double equation turbulence model. The SOD chambers with three kinds of inflow pipe types are analyzed. The results show that the chamber III presents distinct advantages over the others for in situ SOD measurement because the good flow mixing can be achieved and bottom sediment suspension can be avoided in the chamber. The numerical simulation results are compared and validated by laboratory tests.

Keywords: Sediment Oxygen Demand (SOD), Renormalization group (RNG), velocity field, in situ measurement