Trace Dissolved Oxygen Removal Using a Hydrocyclone to Enhance Denitrification

Abstract

Dissolved oxygen (DO) is entrained by mixed liquid recirculation (MLR) into the anoxic basin in the pre-denitrification biological nitrogen removal (PDBNR) process and should be removed to enhance denitrification. A laboratory-scale PDBNR reactor with an anoxic basin divided into two isometric components was built to investigate the effect of a hydrocyclone on DO removal from the MLR and the subsequent denitrification. The denitrification rate of the mixture of influent and hydrocyclone-treated nitrified wastewater increased with increasing DO and was higher than that of the wastewater in a conventional anoxic component. More total nitrogen was removed in the anoxic component due to the application of the hydrocyclone in the MLR of a laboratory-scale reactor and a full-scale anoxic/aerobic reactor.

Enhanced nitrogen removal and in situ microbial community in a two‐step feed oxic/anoxic/oxic‐membrane bioreactor (O/A/O‐MBR) process

“…Although the theoretical value for denitrification is 2.86 g‐COD g ‐1 ‐NO 3 − ‐N, the practical value was commonly higher . The excess COD with C/N of 10.4 in this study might be consumed by the excessive DO derived from the O(II) tank …”

“…26 The excess COD with C/N of 10.4 in this study might be consumed by the excessive DO derived from the O(II) tank. 27…”