Verifying the efficacy in removing nutrients using wastewater treatment stations by constructed wetlands

Abstract

Due to the difficult access to conventional systems of collection and sewage treatment in low income rural communities, there is the need for low cost alternative technologies to treat such effluents. This study aimed to verify the efficacy of sewage treatment systems by constructed wetlands in the removal of the nutrients: nitrogen (N), phosphorus (P), calcium (Ca) and Magnesium (Mg), in two wastewater treatment stations (WWTS) located in a school and in a family house in small communities in the city of Irati/Brazil. Results revealed a good performance in the removal of the nutrients N and P in both systems, 75% and 37% for the house and 41% and 69% for the school, respective; which is associated to the plant uptake ability. However, the index of Ca and Mg presented significant increase, with 156% and 88% for the house and 165% and 128% for the school effluent, respectively, due to the use of gravel (rich in Ca and Mg) in the filter composition.