Abstract
In this study, a novel excess activated sludge (EAS) based nitrification and denitrification process was developed using EAS to
provide nitrifiers and denitrifers for nitrogen removal from the reject water of a municipal wastewater treatment plant (MWWTP).
This can achieve a significant reduction in the nitrogen (N) loading in wastewater treatment plants. The results show that the
ammoniacal-nitrogen (NH4
+-N) and total nitrogen (TN) removal efficiencies were in the range from 74.7% to 93.1% and 77.4% to
87.9%, respectively. The TN removal efficiency was significantly improved when the step-feed strategy was employed.
Therefore, from the technical perspective, the EAS based reject water treatment process can potentially be an alternative pathway
for N removal from the reject water. However, for its full-scale application, integrated cost-effective analysis of process
capabilities and/or its potential effects on dewaterability of EAS should be considered.