Rapid start-up of autotrophic shortcut nitrification system in SBR and microbial community analysis

ABSTRACT

Shortcut nitrification is crucial for application of autotrophic nitrogen removal which is beneficial for treating carbon-limited wastewater. In this experiment, rapid start-up of autotrophic shortcut nitrification system was studied in a small sequencing batch reactor (SBR) built in laboratory with intermittent aeration operation mode. The influent was artificially simulated inorganic domestic wastewater (the ammonium nitrogen concentration was 35.19–57.54 mg/L), the pH value was 7.6–7.8, the hydraulic loading was 1L, the operating temperature was 24.3–28.3 °C, and the dissolved oxygen (DO) was 2–4 mg/L and 0.5–0.9 mg/L at the stage of complete nitrification sludge domestication and shortcut nitrification sludge domestication. High-throughput sequencing technology was used to analyse the composition and changes of microbial populations in sludge. The experimental results showed that on the 24th day of the experiment, shortcut nitrification was started successfully, the accumulation rate of nitrite was 81.63% and the removal efficiency of ammonium nitrogen was 99.25%; the richness of the main denitrifying bacteria phylum Proteobacteria increased from 30.21% to 42.85%; the richness of Nitrosomonas (ammonia oxidizing bacteria, AOB) increased from 0.37% to 22.43%, and at the species level, AOB was the salt-tolerant bacteria Nitrosomonas. europaea; the richness of Nitrospira (nitrite oxidizing bacteria, NOB) decreased from 2.59% to 0.47%.

GRAPHICAL ABSTRACT

KEYWORDS:

• Ammonia oxidizing bacteria
• nitrite oxidizing bacteria
• autotrophic shortcut nitrification system
• high-throughput sequencing
• sequencing batch reactor

Disclosure statement

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

Ethics approval and consent to participate

Authors approve the ethical canons. No ethical committee had to approve such study. No animals or human were involved: ‘Not applicable’.

Consent for publication

Not applicable.

Availability of data and materials

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Additional information

Funding

This work was supported by Chinese National Natural Science Foundations (41502333), the China Postdoctoral Science Foundation (2017M610598, 2018T110963), the National Key Research and Development Program of China (2018YFC0214004), the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Foundation (SKLGP2018Z007, SKLGP2020Z011), the Project of Education Department in Sichuan (18ZB0064) and the Sichuan Science and Technology Support Project (2018JY0518, 2020YJ0148)