Abstract
An external aeration and intermittent circulation were used to improve the nitrogen removal performance of subsurface flow constructed wetland (SSF CW) in landscape garden ponds. Nitrification was the main mechanism of ammonium–nitrogen (
![Math Eq]()
) removal and partial nitrification/anaerobic ammonia oxidation was a minor process. Field measurements yielded a removal rate of
![Math Eq]()
of 0.266–0.566 g N/d m
2 and a corresponding temperature-dependent rate constant of 0.184 d
−1 to 0.377 d
−1 representing an improvement over nitrogen removal. The nitrate–nitrogen (
![Math Eq]()
) removal was degraded to the background level of
![Math Eq]()
concentration in an environment with a high concentration of dissolved oxygen. The
![Math Eq]()
removal rate ranged from 0.0393 g N/d m
2 to 0.0825 g N/d m
2 and resulted from aerobic denitrification, indicating that external aeration and intermittent circulation effectively improved oxygen transportation in SSF CW. This could remove
![Math Eq]()
of the effluent of SSF CW when using in-tank aeration to improve the nitrogen removal performance of SSF CW.
) removal and partial nitrification/anaerobic ammonia oxidation was a minor process. Field measurements yielded a removal rate of 
) removal was degraded to the background level of