NH₃ biofiltration of piggery air

Area of Science:

• Environmental Engineering
• Agricultural Science
• Biotechnology

Background:

• Ammonia (NH3) emissions from piggeries pose environmental and health challenges.
• Biofiltration offers a potential solution for treating agricultural air pollutants.
• Optimizing biofilter design and operation for agricultural settings is crucial.

Purpose of the Study:

• To evaluate the performance of a pilot-scale wood chip biofilter for treating ammonia emissions from a French piggery.
• To assess the impact of climatic conditions on biofilter efficiency.
• To provide insights for large-scale biofilter applications in agriculture.

Main Methods:

• A pilot-scale biofilter using wood chips was operated under simulated summer and autumn conditions.
• Experiments involved varying empty bed residence times (EBRTs) and monitoring ammonia loading rates (LR).
• Inlet ammonia concentrations, removal efficiencies (RE), temperature, and relative humidity were recorded.

Main Results:

• Significant ammonia removal (90-100% RE) was achieved at an EBRT of 12 s and LR of 4 g m⁻³ h⁻¹ during summer.
• Lower EBRTs (6 s) resulted in reduced RE (30-50%) due to increased LR and influenced by atmospheric conditions.
• Autumn tests showed around 80% RE at 3 g m⁻³ h⁻¹ LR, highlighting the need for demister systems to manage moisture.

Conclusions:

• Wood chip biofilters are suitable for treating piggery ammonia emissions.
• Biofilter performance is significantly affected by climatic factors like temperature and humidity.
• Effective management requires precise control of medium moisture content, posing challenges for easy farm implementation.