Modelling the fate of nitrogen in a wastewater treatment plant effluent dominant river

Excessive anthropogenic nitrogen was added to the river system by WWTP effluent, which present a water-quality problem of growing concern. Here we present an approach to study the nitrogen dynamics and improve the understanding of the nitrogen cycling by coupling high spatial resolution monitoring data and modelling. Our results showed that denitrification accounted for an average 24% of the total nitrogen removal upstream of WWTP effluent, while it accounted for an average 99% of total nitrogen removal downstream. The section downstream of the WWTP effluent was identified as the "hot spot" for nitrogen removal by denitrification.