Advanced Water Management Centre

AWMC Seminar Program: Evaluating the impact of FNA side-stream treatment on combined nitrogen and phosphorus removal system

Evaluating the impact of FNA side-stream treatment on combined nitrogen and phosphorus removal system

Xuanyu Lu

Abstract: Inline side stream with free nitrous acid (FNA) treatment has been recently considered as a key strategy to effectively enhance methane production, improve dewaterability and reduce sludge disposal in wastewater treatment. One key component of FNA side-stream treatment is to selectively eliminate nitrite oxidising bacteria (NOB) from the system while retaining ammonium oxidising bacteria (AOB), using an appropriate FNA concentration range (e.g. 0.02-0.03 mg N/L).  However, anabolic and catabolic process of some phosphorus accumulating organisms (PAOs) would be seriously inhibited under this FNA concentration range, resulting in a deterioration in biological phosphorus removal processes.

The aim of this study is to develop a combined nitrogen and phosphorus removal system with FNA side-stream treatment. Considering FNA treatment, the real sludge retention time (SRT) could be reduced in the mainstream bioreactor system. Previous research showed that some atypical PAOs can survive under very short sludge retention time (e.g. 2-4 days) and function efficiently. Therefore, we hypothesise that the FNA side-stream treatment system will be able to offer an opportunity to achieve combined N and P removal in a system where a “short SRT” is applied to select for a different community of PAOs.  In this thesis, the impact of FNA side-stream treatment on combined N and P removal wastewater treatment systems will be studied on a microbiological, metabolic and operational level.

AWMC hosts a free seminar series, every Friday at 9am in the AIBN Building.

Event Details
Date & Time: 
Wednesday, 31 October 2018
1pm - 2pm
Venue: AIBN Building 75, Level 1 Seminar Room

Event Contact: awmcseminars@awmc.uq.edu.au