Constructed wetland is a suitable technology mainly diffused for treating wastewater coming from small and medium municipalities and from decentralized settlements (holiday resorts, shopping centers) where high variability in wastewater flow and quality occurs. In addition they are increasingly used to treat agricultural and animal wastewater, landfill lecheates, industrial wastewater, runoff. The paper presents the features of the different phytoremediation systems, the role of the vegetation and the characteristics of the most interesting species. Examples of some systems installed in Southern and Northern Italy are here presented. In particular a constructed wetland for wastewater treatment of IKEA store in Catania allowed to obtain water always satisfacting the limits imposed by the Italian Legislation to discharge the wastewater in surface water bodies. Similarly, satisfactory performance was obtained also by floating wetland systems installed in different locations of North Italy.
Keywords: Subsurface horizontal flow systems, Subsurface vertical flow systems, surface flow systems, floating systems, removal efficiency