Start up partial nitrification at low temperature with a real-time control strategy based on blower frequency and pH

Area of Science:

• Environmental Science
• Microbiology

Background:

• Partial nitrification is crucial for nitrogen removal in wastewater treatment.
• Low temperatures pose challenges for efficient nitrification processes.

Purpose of the Study:

• To investigate partial nitrification via nitrite at low temperatures.
• To evaluate a novel real-time control strategy for optimizing this process.

Main Methods:

• A pilot-scale sequencing batch reactor (SBR) was used.
• A real-time control strategy based on blower frequency (BF) and pH was implemented.
• Nitrogen break point (NBP) and nitrate/nitrite apex point (NAP) were identified.

Main Results:

• Partial nitrification was achieved within 40 days at 11-16°C.
• Nitrite accumulation rate (NAR) increased to 90%.
• The process was stably maintained for 140 days.

Conclusions:

• The real-time control strategy effectively enables partial nitrification at low temperatures.
• Ammonia-oxidizing bacteria (AOB) became dominant over nitrite-oxidizing bacteria (NOB).
• This approach offers a stable and efficient method for low-temperature nitrogen removal.