Performance of short-cut denitrifying phosphorus removal and microbial community structure in the A²SBR process

ABSTRACT

Acclimatization of short-cut denitrifying polyphosphate accumulating organisms (SDPAOs), metabolic mechanism, and operating parameters were analyzed to investigate the performance of the anaerobic/anoxic sequencing batch reactor (A²SBR) process. The high-throughput sequencing technology was employed to explore the microbial community structures of activated sludge systems. The experimental results illustrated that SDPAOs were successfully enriched with three-phase inoculation for 36 days. The removal rates of TP and NO₂⁻-N were 93.22% and 91.36%, respectively, under the optimal parameters of a pH of 7.5, an SRT of 26 days, a temperature of 24 ℃ and a COD of 200.00 mg·L⁻¹ using acetate as the carbon source. In the anaerobic stage, 82.20% external carbon source was converted into 88.78 mg·g⁻¹ PHB, and the removal rate of NO₂⁻-N in the anoxic stage was characterized by ΔNO₂⁻-N/ΔPHB, anoxic ΔP/ΔPHB_effective was 0.289, which was higher than anaerobic ΔP/ΔCOD_effective of 0.203. Ignavibacterium and Povalibacter with significant phosphorus removal ability were the dominant bacterial genera. The nitrogen and phosphorus removal could be realized simultaneously in an anaerobic/anoxic sequencing batch reactor. Therefore, this study provided an important understanding of the removal of nitrogen and phosphorus from low-carbon nitrogen wastewater.

GRAPHICAL ABSTRACT

KEYWORDS:

• SDPAOs
• A²SBR
• microbial community
• metabolic mechanism
• low C/N sewage

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study were obtained through experiments.

Additional information

Funding

This study was financially supported by Liaoning Applied Basic Research Program Project (2023030002-JH2/1013), and Shenyang Science and Technology Plan Project (22322310).