Laboratory and field studies on a new sensor for dissolved N₂O

Area of Science:

• Environmental Science
• Analytical Chemistry
• Chemical Engineering

Background:

• Nitrous oxide (N₂O) is a potent greenhouse gas with increasing atmospheric concentrations.
• Wastewater treatment plants (WWTPs) are significant sources of N₂O emissions.
• Effective N₂O mitigation requires real-time monitoring in both liquid and gas phases.

Purpose of the Study:

• To develop and validate a system for online monitoring of N₂O concentrations in wastewater.
• To enable efficient N₂O emission control strategies in WWTPs.
• To facilitate the optimization of N₂O exploitation in biogas combustion.

Main Methods:

• Membrane extraction of N₂O from the liquid phase.
• Subsequent gas-phase analysis using photoacoustic spectroscopy.
• Comparison of theoretical extraction efficiency models (mathematical vs. finite element simulation) with experimental data.
• Field testing of a developed probe on a WWTP.

Main Results:

• The proposed membrane extraction system coupled with photoacoustic spectroscopy demonstrated good agreement between theoretical calculations and experimental measurements.
• A field probe was successfully developed and tested on a WWTP.
• Results from the field probe were comparable to established Gas Chromatography (GC) reference analysis.

Conclusions:

• The developed system provides a reliable method for online N₂O monitoring in WWTPs.
• This technology supports strategies for minimizing N₂O emissions and optimizing biogas utilization.
• Real-time gas extraction and analysis are crucial for effective environmental management of WWTPs.