Nitrogen removal in constructed wetlands

Abstract

The most important processes responsible for nitrogen removal in constructed wetlands (CWs) are nitrification and denitrification. These processes were well-described in the second part of the 19th century and are still valid. During the recent years, other processes responsible for nitrogen removal in CWs have been identified, namely anaerobic ammonia oxidation (Anammox), anaerobic ammonia-oxidation-coupled-to-dissimilatory ferric iron reduction (Feammox) and autotrophic denitrification. Also, bacteria that can perform complete oxidation of ammonia to nitrate (Comammox) have been discovered. This review is mostly aimed at these newly discovered processes in relation to wastewater treatment in CWs.