Numerical Analysis of the Performance of Horizontal and Wavy Subsurface Flow Constructed Wetlands

A three-dimensional numerical model is proposed for modeling the TP transport in the Horizontal Subsurface Flow (HSSF) and Wavy subsurface Flow (WSSF) constructed wetland in this article. Both numerical simulations and physical experiments indicate that the removal efficiency of WSSF is higher than that of HSSF. The difference of performance in removing pollutants, e.g., Total Phosphorus (TP), between HSSF and WSSF is numerically analyzed from three interactive aspects, that is, the hydraulic behavior, the substrate and the plant roots. It is shown that the dead zone volume in WSSF is smaller than in HSSF with less short circuiting. The soil in the top layer is more used in WSSF than in HSSF. The TP uptake by the plant roots in WSSF is higher than that in HSSF.