Microbial community response to influent shift and lowering temperature in a two-stage mainstream deammonification...

Area of Science:

• Environmental Microbiology
• Wastewater Treatment Engineering
• Biotechnology

Background:

• Wastewater treatment processes are sensitive to influent composition and temperature changes.
• Partial nitritation (PN) and anammox processes are crucial for nitrogen removal but can be affected by operational shifts.

Purpose of the Study:

• To investigate the impact of switching from synthetic to real sewage influent, combined with lower temperatures, on the microbial communities in a two-stage PN-anammox system.
• To assess the stability and function of the microbial community under these new conditions.

Main Methods:

• High-throughput sequencing was employed to analyze bacterial community composition.
• Venn diagrams and Hill numbers were used to evaluate diversity changes.
• Taxonomic analysis identified key bacterial groups and their abundance shifts.

Main Results:

• Bacterial diversity significantly increased in both PN and anammox reactors.
• The PN reactor showed enrichment of heterotrophic bacteria and a reduction in autotrophic species.
• The anammox reactor maintained dominant bacteria with only slight abundance decreases, and incoming bacteria did not impair anammox function.

Conclusions:

• The shift to real sewage and lower temperatures positively influenced microbial diversity in the PN-anammox system.
• The first-stage PN reactor plays a vital role in maintaining the stability of the subsequent anammox microbial community.
• Nitrosomonas europaea and Candidatus Brocadia remained the dominant functional species in their respective reactors.