Treatment of Municipal Wastewater by Subsurface Flow Wetlands Modified to Rural Communities in Mexico

Abstract

In this work, efficiency and quality of water by artificial wetland with subsurface flow were obtained. This wetland is 12.15 m long and 8 m wide with three channels. Its substrate bed consists of volcanic rock (“tezontle”), with three particle size (5-10, 10-15 and 15-20 cm), where the influence of porosity and its relation to hydraulic conductivity were determined, both parameters were related to Manning and Darcy equations for obtain water flow behaviour in each channel of wetland. The system was planted with Phragmites australis and Typha latifolia. For input to each channel were designed curved shapes with slope of radius 2.67 m, to avoid short circuits, with 6% minimum curvature, 1% slope, 0.5 m/min minimum velocity, and 2 L/s of flow (expense). Quality parameters of treated water were evaluated and with IBER software was modelled the hydrodynamic from wetland. It was concluded from results that curves sloped forms in channels improve treatment, achieving more efficiency. Furthermore the result of hydrodynamic modelling indicates that flow between channels is homogeneous, continuous and short circuits are avoided.