Predicting nitrogen and phosphorus removal in wetlands due to detritus accumulation: A simple mechanistic model

Constructed wetlands have shown a substantial capacity for wastewater treatment under a wide range of conditions, but removal efficiency of nitrogen (N) and phosphorus (P) has been inconsistent and is often low. Models designed to predict N and P removal in wetlands include complex numerical efforts and empirical models, both of which have shortcomings. In this paper we present a simple mechanistic model capable of predicting N and P removal by detritus accumulation in constructed wetlands. Implications of the simplifications made in this model are explored through simulation modeling. Preliminary validation with one system suggests that the model holds promise. The dominant role of refractory organic matter suggests that more research is needed on this topic.