Achieving mainstream anammox in biological aerated filter by regulating bacteria community structure

Area of Science:

• Environmental Microbiology
• Wastewater Engineering
• Biotechnology

Background:

• Partial nitrification-anammox (PN-A) is efficient but unstable due to bacterial competition.
• Achieving stable PN-A in mainstream conditions remains a challenge for wastewater treatment.

Purpose of the Study:

• To investigate achieving one-stage mainstream anammox by manipulating bacterial community structure.
• To assess the effectiveness of a lab-scale biological aerated filter (BAF) for this process.

Main Methods:

• Utilized a lab-scale biological aerated filter (BAF).
• Regulated bacterial communities through backwashing and alternating high/low ammonia nitrogen (NH4+-N) concentrations.
• Monitored key parameters like free ammonia and nitrite nitrogen (NO2--N).

Main Results:

• High free ammonia (89.57 mg/L) and NO2--N competition were observed.
• Backwashing successfully shifted the bacterial community, making Candidatus Kuenenia dominant (5.56% abundance).
• Achieved total nitrogen (TN) below 15 mg/L in effluent via controlled recovery lag-time.

Conclusions:

• One-stage mainstream anammox is feasible by managing bacterial communities in BAF systems.
• The strategy of alternating ammonia levels and backwashing shows promise for municipal wastewater treatment plants (MWWTPs).