Phytoremediation represents the set of technologies able to remove pollutants using artificial ecosystems equipped with natural plants. This book examines a survey about the state of the art of this technique and provides results and details about new applications. The first part deals with wastewaters phytoremediation technique, providing a description of clean-up mechanisms, treatment plants configurations, applicability and removal efficiencies through the analysis of the most recent literature data. The second part consists of a case study in which design, construction and monitoring of real-scale pilot treatment wetland built in a cold climate as primary treatment for dairy wastewaters are examined.