Treatment wetlands (TW) are a green technology that reproduce in a confined area the chemicals, physicals and biological reactions that occurs in natural wetland systems.
The water quality improvements in natural wetlands had been observed by scientists and engineers for many years. This led to the development of CW as an attempt to replicate the water quality and the habitat benefits of the natural wetland in a constructed ecosystem to serve human water pollution.
Due to his natural origin and behaviour TW are complex systems in terms of biology, hydraulics and water chemistry.
Natural and constructed wetlands rely on solar insulation as a main driving energy, and warmer climates improve treatment rates (Kadlec,1996).
Within this system various kind of wastewaters are treated and transformed by the complex plants-fill medium-microbial colonies that develop and progress during the years inside the treatment bed (Cooper 1996, Masi 2000, Shepherd 2001, Borin 2005, Tocchetto 2006, 2007). The biological reactions are due to the activity of micro organisms attached to the available submerged substrate surfaces (plant roots growing in the media, and the surfaces of the media themselves).