Nitrogen and sulfur compounds from animal agriculture and their potential interactions for aerosol forming reactions

Authors: Silva, Philip - Phil; NEE, MATTHEW - Western Kentucky University; PURVIS-ROBERTS, KATIE - Claremont Colleges; COCKER III, DAVID - City Of Riverside

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/31/2022
Publication Date: N/A
Citation: N/A

Interpretive Summary: .

Technical Abstract: Animal feeding operations emit a variety of air emissions including greenhouse gases, ammonia, hydrogen sulfide, and volatile organic compounds. While the greenhouse gases are largely unreactive and therefore have long lives in the atmosphere, the other compounds can react in the atmosphere to produce secondary species including ozone and aerosol. Secondary aerosol from these compounds would add to the primary particulate matter (fugitive dust and other components) also produced from agricultural operations. Here we describe a combination of field and laboratory measurements to understand the importance of these compounds to agricultural impacts on air quality. Poultry, swine, and dairy operations have been studied to measure concentrations of ammonia, hydrogen sulfide, amines, organic sulfides, and aerosol size distributions present in the air near operations. Ammonia, as expected, is always high near source (part per million levels). Sulfur concentrations vary dramatically from one operation to another and are strongly related to manure handling methods. Peak values of hydrogen sulfide can hit hit high part per billion levels during waste movement. Amine and organic sulfide concentrations are significantly less at low part per billion levels. Near source, most of the aerosol size distribution is in the accumulation mode where secondary aerosol components A series of environmental chamber experiments have been performed to investigate the possible interactions of these compounds. In these experiments, nitrogen and sulfur gaseous compounds from agriculture are exposed to atmospheric oxidation processes to detect potential aerosol formation reactions. Though ammonia is normally thought of as the main agricultural contributor to aerosol formation via reaction with sulfate and nitrate salts, our experiments show that the amines also have significant aerosol formation potential. Similarly, the organic sulfides have significantly higher formation potential than hydrogen sulfide. However, when located together with reduced sulfur and nitrogen compounds present in proximity to each other, the aerosol formation increases further due to having precursors to both cation and anion salts present. These experiments suggest that modeling of agriculture influences to particulate matter should be performed looking more at the aggregate whole than just focusing on ammonia.