Name

Combating greenhouse gas emissions: using pure oxygen injection to reduce nitrous oxide emissions in wastewater treatment plants

Speakers

Izba Ali

Authors

Izba Ali, Air Liquide, France
Roel Boussemaere and Rudy Lamond, Air Liquide, Belgium
Tomas Alexandersson, Air Liquide, Sweden

Description

Laughing gas (N₂O) emissions from wastewater treatment plants (WWTPs) are a significant source of greenhouse gas (GHG) emissions. To achieve climate neutral operation, these emissions must be addressed. This study investigated the impact of pure oxygen injection on N₂O emissions at a WWTP treating leachate from composting green waste. The plant was equipped with surface aerators and bottom-mounted mechanical aerators for pure oxygen injection. The research combines computational fluid dynamics (CFD) analysis and drone-based N₂O measurements. The CFD modeling simulates different aeration scenarios to predict N₂O emissions, while drone measurements capture real-time N₂O emissions data to measure the effects of pure oxygen injection. The modeling results indicated that autotrophic denitrification and hydroxylamine oxidation were major contributors to N₂O production. The model also showed that approximately 84% of N₂O emissions could be eliminated by combining surface aeration with pure oxygen injection at the bottom. Moreover, full-scale drone measurement campaigns confirmed that switching from surface aeration to a combination of surface aeration and bottom injection of pure oxygen led to a substantial reduction (67%) in N₂O emissions. This study offers valuable insights for WWTP operators and engineers seeking to implement sustainable practices and reduce GHG emissions while maintaining operational efficiency.

Time

2:05 PM - 2:17 PM

Location Name

Room 2

Track

14:05 - 15:45 Technology Showcase