The main purpose of this study is to determine the removal efficiency of nitrogen compounds in the effluentfrom ANAMMOX process used to treat reject water after centrifugation. A pilot model was bulit consisting of fourdifferent Treatment Wetlands beds with different filter substrate and with or without macrophytes growth. Verticalsubsurface flow type filters have been choosen thanks to their highest efficiency in NH4-N removal and better resistanceto high fluctuations of influent composition. The pilot was feed with synthetic sewage prepaired on-site every day duringthe study. Samples have been taken for analysis to determine the changes of NH4-N, NO3-N and NO2-N in the effluentof each filter. In bed “0” the removal of nitrogen compounds was caused only by sorption and lasted till its capacity wasreached. In bed “I” and “II” the NH4-N concentration in effluent and production of NO2-N with simultaneous changesof NO3-N indicated that nitrification was occurring. Furthermore assimilation by plants and sorption processes by substratecontributet to the removal of nitrogen compunds. The investigation reviles different pattern of processes responsiblefor N - compounds transformation and removal, depending on the bed substrate and vegetation or without vegetation.

DOI: https://doi.org/10.3846/enviro.2017.086