Effect of intermittent induced aeration on nitrogen removal and denitrifying-bacterial community structure in Cork and gravel vertical flow pilot-scale treatment wetlands

Fil: Aguilara, Lorena. Universitat Politécnica de Catalunya; España Fil: Aguilara, Lorena. UNESCO Chair on Sustainability; Francia Fil: Gallegos, Ángel. UNESCO Chair on Sustainability; Francia Fil: Gallegos, Ángel. Universitat Politécnica de Catalunya; España Fil: Pérez, Leonardo Martín. Pontificia Universidad Católica Argentina. Facultad de Química e Ingeniería del Rosario. Instituto de Investigaciones en Ingeniería Ambiental, Química y Biotecnología Aplicada; Argentina Fil: Pérez, Leonardo Martín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentinas Fil: Pérez, Leonardo Martín. Politécnica ecnica de Catalunya; España Fil: Pérez, Leonardo Martín. NESCO Chair on Sustainability; Francia Fil: Arias, Carlos A. University of Aarhus. Department of Biological Sciences; Dinamarca Fil: Arias, Carlos A. Aarhus University. Centre for Water Technology; Dinamarca Fil: Rubio, Raquel. Universitat Politécnica de Catalunya; España Fil: Rubio, Raquel. UNESCO Chair on Sustainability; Francia Fil: Haulani, Leila. Universitat Politécnica de Catalunya; España Fil: Haulani, Leila. UNESCO Chair on Sustainability; Francia Fil: Garciá Raurich, Josep. Universitat Politécnica de Catalunya. Centro de Investigación en Seguridad y Control Alimentario; España Fil: Pallarés, Marc. Grupo de Desarrollo Empresarial; España Fil: de Pablo, Joan. Universitat Politécnica de Catalunya. Resource Recovery and Environmental Management; España Fil: Morató, Jordi. Universitat Politécnica de Catalunya; España Fil: Morató, Jordi. UNESCO Chair on Sustainability; Francia Abstract: In this work, we have evaluated the impact of intermittent induced aeration in total nitrogen (TN), ammonia (NH4-N) and nitrate-nitrogen (NO3-N) removal in four pilot-scale vertical flow constructed wetlands (VFCW) (two aerated two non-aerated) using cork by-product or gravel as the filter material and planted with Phragmites australis. Both aerated and non-aerated systems achieved high COD and BOD5 elimination rates ( 90%) at the end of the 5-month test period. However, the aerated systems presented maximal COD and BOD5 removal from the third month of operation onwards since air supply favored the oxidative bioprocesses occurring within the wetlands. Cork and gravel aerated VFCW also proved to be more efficient (p