The constructed wetlands are treatment and disposal systems, which mimic the environment and also have aesthetic value - they can be incorporated in the surrounding land arrangements. There are two main types – subsurface flow and free surface flow. The video shows a scheme, which incorporates preliminary treatment in the form of a septic tank, followed by an aeration chamber, subsurface wetland and a surface wetland as a final treatment stage.
Special vegetation, typical for wet environments is applied, such as cattails, reed, etc. Passing through the root systems of the plants, the wastewater is partially treated by biological means and partially evaporated. The wetlands are designed based on their capacity to remove organic materials and the climatic conditions in the locality. It should be noted, that the constructed wetlands usually do not absorb the whole amount of wastewater at the inlet and therefore are only partially disposing it. The effluent is considered save for reuse, if the wetlands are designed and operated properly.