Ammonia, hydrogen sulfide, and greenhouse gas emissions from lab-scaled manure bedpacks with and without aluminum sulfate additions

Authors: Spiehs, Mindy; Woodbury, Bryan; Parker, David

Submitted to: Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/18/2019
Publication Date: 9/20/2019
Citation: Spiehs, M.J., Woodbury, B.L., Parker, D.B. 2019. Ammonia, hydrogen sulfide, and greenhouse gas emissions from lab-scaled manure bedpacks with and without aluminum sulfate additions. Environments. 6:108. https://doi.org/10.3390/environments6100108.
DOI: https://doi.org/10.3390/environments6100108

Interpretive Summary: Air quality near cattle feedlot facilities is a concern for livestock producers. There is increasing pressure for livestock producers to not only reduce odor, but to lower greenhouse gas emissions, and emissions of gases such as ammonia and hydrogen sulfide which can be harmful to humans and animals. The poultry industry has successfully lowered ammonia emissions from poultry barns by aluminum sulfate (commonly called alum) to the litter. The alum lowers the pH of the litter, which prevents nitrogen from being converted to ammonia and volatilizing into the air. Changing the pH of the litter has also been shown to change the microbial community in the litter, which may reduce pathogens and potentially alter odors that are emitted. This study was conducted to see if alum could be used in a similar way on beef feedlots. It was conducted in a lab, using buckets with corn stover bedding. Urine and feces were added to the bedding three times per week for 6 weeks. Alum was added at a rate of 0, 2.5, 5, or 10% of the total mass. In one-half of the buckets, all the alum was added on the first day. In the other one-half of the pans, alum was added weekly. Ammonia emissions were reduced when 10% alum was added to the bedded pack. When all of the alum was added on Day 0, the 10% alum effectively lowered NH3 emission for 21 days compared to the bedded packs containing 0% alum. Weekly additions of 10% alum effectively lowered NH3 emissions relative to 0% alum for the entire 42-day sampling period. However, hydrogen sulfide emissions and methane emissions increased when alum was added. The study found that weekly additions of 10% alum were most effective in lowering ammonia emissions but other gases may increase when alum is used.

Technical Abstract: The poultry industry has successfully used aluminum sulfate (alum) as a litter amendment to reduce NH3 emissions from poultry barns, but alum has not been evaluated for similar uses in cattle facilities. A study was conducted to measure ammonia (NH3), greenhouse gases (GHG), and hydrogen sulfide (H2S) emissions from lab-scaled bedded manure packs over a 42-day period. Two frequencies of application (once or weekly) and four concentrations of alum (0, 2.5, 5, and 10% by mass) were evaluated. Frequency of alum application was either the entire treatment of alum applied on Day 0 (once) or 16.6% of the total alum mass applied each week for six weeks. Ammonia emissions were reduced when 10% alum was used, but H2S emissions increased as the concentration of alum increased in the bedded packs. Nitrous oxide emissions were not affected by alum treatment. Methane emissions increased as the concentration of alum increased in the bedded packs. Carbon dioxide emissions were highest when 5% alum was applied and lowest when 0% alum was used. Results of this study indicate that 10% alum is needed to effectively reduce NH3 emissions, but H2S and methane emissions may increase when this concentration of alum is used.