|LI, HONG - University Of Delaware|
|BURNS, ROBERT - University Of Tennessee|
|MAGUIRE, RORY - Virginia Tech|
|OGEJO, JACTONE - Virginia Tech|
|REITER, MARK - Virginia Tech|
|BUSER, MICHAEL - Oklahoma State University|
Submitted to: Frontiers in Sustainable Food Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/29/2018
Publication Date: 6/15/2018
Citation: Moore Jr., P.A., Li, H., Burns, R., Miles, D.M., Maguire, R., Ogejo, J., Reiter, M., Buser, M., Trabue, S.L. 2018. Development of the ARS air scrubber: A device for reducing ammonia, dust and odor in exhaust air from animal rearing facilities. Frontiers in Sustainable Food Systems. 2:1-10.
Interpretive Summary: Emissions of ammonia, dust and odors from animal feeding operations can result in air pollution and neighbor disputes. The objectives of this research were to (1) re-design the ARS Air Scrubber to improve ammonia removal efficiency, (2) conduct full-scale testing of the scrubber under controlled conditions, (3) evaluate the practicality and efficacy of various acids for scrubbing ammonia, and (4) determine the effects of air flow rate and ammonia concentration on scrubber performance. We built a full-scale prototype and conducted a series of experiments under controlled conditions. The most practical acid to use for the scrubber was sodium bisulfate. The relative efficiency of the scrubber for reducing ammonia concentrations in exhaust air reduced as the ventilation rate increased, however, the ammount of nitrogen captured increased dramatically. Likewise, as ammonia concentration going into the scrubber were increased from 10 to 75 ppm, the relative ammonia reduction decreased slightly, however, the mass captured increased by almost ten-fold. This scrubber has the potential to capture a large fraction of the nitrogen lost from animal feeding operations while simulatanterould reducing emissions of bacteria, dust and odors.
Technical Abstract: Ammonia (NH3), dust and odor emissions from animal feeding operations (AFOs) can cause atmospheric pollution and cause disputes with neighbors living near farms. The objectives of this study were to: (1) re-design the ARS Air Scrubber to improve NH3 removal efficiency, (2) conduct full-scale testing of the scrubber under controlled conditions, (3) evaluate the practicality and efficacy of various acids for scrubbing NH3, and (4) determine the effects of air flow rate and NH3 concentration on scrubber performance. A full-scale prototype was constructed and a series of experiments were conducted under various conditions. Sodium bisulfate (NaHSO4) was found to be the most practical acid to use with respect to safety concerns and ease of use. The efficiency of the scrubber for capturing NH3 decreased as the ventilation rate increased from over 90% at flow rates of 5,097 m3/hr (3,000 cfm) to around 55% at 16,141 m3/hr (9,500 cfm). However, the mass of N captured by the scrubber tripled as flow rates increased from 5,097 to 16,141 m3/hr . Similarly, there was a slight reduction in NH3 removal efficiency as inflow NH3 levels were increased from 10 uL/L to 75 uL/L, whereas the mass of N captured increased from 25 g N/hr to around 200 g N/hr. This technology could potentially result in the capture of a large fraction of the N lost from AFOs, while simultaneously reducing emissions of bacteria, dust, and odors, which would improve the social, economic, and environmental sustainability of poultry and swine production.