The Wetland system has been presented as an alternative to the biological treatment of sewage. It is a process that uses physical, chemical and biological filtration in the transformation / purification of pollutants present in the sanitary or industrial sewage, degrading organic matter, recycling the nutrients and consequently, improving water quality. This type of system has several advantages, such as: low cost of operation, maintenance, implementation and operation; low energy consumption; and costs with final disposal of the sludge is eliminated.
The uses of Wetlands demonstrate good efficiencies in the removal of suspended solids, BOD and nutrient concentration (Phosphorus and Nitrogen). Removal of organic matter and nutrients within a Wetland filter is due to the use of aquatic macrophytes.
These species are used because they have adaptations to the different types of environments, from swamps to totally submerged environments. Wetlands can be surface or subsurface flow.