Construction of a Wetland
A constructed wetland usually consists of two components: The mechanical and the biological/organic treatment stage. A ‘vertical flow wetland’ (VF) is a planted filter bed that is drained at the bottom. By means of a mechanical dosing system, water is poured onto the surface. The feed of the organic water-treatment plants either functions with the aid of a submersible pump or a slug feeder in a ducted incline. In the settling pit, solid constituents of the sewage are withheld and removed. Subsequently, the sewage flows vertically down through a planted retention soil filter (under gravel filter). At the bottom of the wetland, it is collected in a drainage pipe.
Slug Feeder
This system works automatically and thus, external power supply is not needed. The sewage is gathered in a chamber and after reaching a certain level, the water is fed by surges into the sewage system. Its function is explained in the following clip:
Where to Put the Purified Water of the Wetland?
Water that has flowed through a constructed wetland is highly efficiently purified (biologically as well as mechanically). It can be easily used for irrigation purposes and it can be drained into the next outlet channel or drained away into the subsoil. The discharge values at all locations lie below the legally allowed levels throughout the year.
