Sediment retention in constructed wetland ponds--a laboratory study.

Laboratory experiments on sediment removal and particle settlement were conducted in a hydraulic laboratory model scaled 1:1 to study processes and mechanisms governing sediment transport under well defined and reproducible conditions. Parameters governing particle settling were varied and their effect studied ceteris paribus. These governing parameters were flow velocity, TSS input concentration, presence of plants, vegetation density, and the presence of wind.

Salt tracer experiments in constructed wetland ponds with emergent vegetation: laboratory study on the formation of density layers and its influence on breakthrough curve analysis.

Constructed wetlands are a rapidly expanding and intensively studied wastewater treatment system. One of the main types in use is the free water surface (FWS) wetland or wetland pond. In studies on these ponds, salt tracer experiments are a convenient tool to determine travel time distributions, which are, in turn, related to hydraulic and sedimentation (trapping) as well as nutrient removal efficiencies.