Constructed Wetlands for the Wastewater Treatment: A Review of Italian Case Studies

Wastewater is one of the major sources of pollution in aquatic environments and its treatment is crucial to reduce risk and increase clean water availability. Constructed wetlands (CWs) are one of the most efficient, environmentally friendly, and less costly techniques for this purpose. This review aims to assess the state of the art on the use of CWs in removing environmental pollutants from wastewater in Italy in order to improve the current situation and provide background for future research and development work. To evaluate the CWs performances, 76 research works (2001-2023) were examined, and the parameters considered were the type of wastewater treated, pollutants removed, macrophytes, and the kinds of CWs utilized. The pollutant removal efficiencies of all CWs reviewed showed remarkable potential, even though there are biotic and abiotic factor-driven performance variations among them. The number of articles published showed an increasing trend over time, indicating the research progress of the application of CWs in wastewater treatment. This review highlighted that most of the investigated case studies referred to pilot CWs. This finding suggests that much more large-scale experiments should be conducted in the future to confirm the potential of CWs in eliminating pollutants from wastewater.