ABSTRACT
This chapter describes the strategy of the constructed wetlands for treating domestic and/or industrial wastewater until now and to describe the use of constructed wetlands under a perspective of the global change scenario. Constructed wetlands are engineered systems that have been designed and constructed to treat water or biosolids under different operational conditions. According to hydraulic characteristics, they are classified in three types of wetlands: surface flow (SF), horizontal subsurface (HSSF), and vertical subsurface constructed wetlands (VSSF). SF wetlands are a type of constructed wetlands where the wastewater is exposed to the atmosphere. HSSF wetland is a system where wastewater circulates through the support medium, rhizomes, and roots plants. In a VSSF wetland, wastewater is fed intermittently onto the bed surface flooding the entire surface and then by gravity, percolates and drains through the medium support. Hybrid constructed wetlands are systems which operation and performance consists in a combination of various constructed wetlands operated sequentially.
