Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6302577 | Ecological Engineering | 2013 | 7 Pages |
Nitrification and denitrification have been proved to be the main pathways for nitrogen removal in constructed wetlands (CWs), but they usually could not occur in a single wetland unit simultaneously due to conflicting oxygen demand. In this study, we employed two artificial aeration modes including continuous aeration (CA) and intermittent aeration (IA) in lab-scale vertical flow constructed wetlands (VFCWs) to investigate the nitrogen removal performance with different influent COD/N ratios. The artificial aeration significantly enhanced NH4+-N removal, especially for the wetland units with higher COD/N ratios. The variations of aeration modes and COD/N ratios also had a great effect on nitrogen removal. The IA units had a better performance on nitrogen removal compared to CA units when the COD/N ratio ranged from 5 to 10. Plant biomass and nitrogen accumulation by plant were also studied. It was observed that plants in IA and CA had less biomass and nitrogen uptake at lower COD/N ratios, but plants in IA could achieve a better performance with higher COD/N ratios.