title: Preliminary investigation of air bubbling and dietary sulfur reduction to mitigate hydrogen sulfide and odor from swine waste.
abstract: When livestock manure slurry is agitated, the sudden release of hydrogen sulfide (H(2)S) can raise concentrations to dangerous levels. Low-level air bubbling and dietary S reduction were evaluated as methods for reducing peak H(2)S emissions from swine (Sus scrofa) manure slurry samples. In a first experiment, 15-L slurry samples were stored in bench-scale digesters and continuously bubbled with air at 0 (control), 5, or 10 mL min(-1) for 28 d. The 5-L headspace of each digester was also continuously ventilated at 40 mL min(-1) and the mean H(2)S concentration in the outlet air was <10 microL L(-1). On Day 28, the slurry was agitated suddenly. The peak H(2)S concentration exceeded instrument range (>120 microL L(-1)) from the control treatment, and was 47 and 3.4 microL L(-1) for the 5 and 10 mL min(-1) treatments, respectively. In a second experiment, individually penned barrows were fed rations with dietary S concentrations of 0.34, 0.24, and 0.15% (w/w). Slurry derived from each diet was bubbled with air in bench-scale digesters, as before, at 10 mL min(-1) for 12 d and the mean H(2)S concentration in the digester outlet air was 11 microL L(-1). On Day 12, the slurry was agitated but the H(2)S emissions did not change significantly. Both low-level bubbling of air through slurry and dietary S reduction appear to be viable methods for reducing peak H(2)S emissions from swine manure slurry at a bench scale, but these approaches must be validated at larger scales.
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, 4-10 Agriculture and Forestry Centre, Edmonton, Canada. grant.clark@ualberta.net
authors.forename: O Grant
authors.initials: OG
authors.lastname: Clark
authors.forename: Brent
authors.initials: B
authors.lastname: Morin
authors.forename: Yongcheng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Willem C
authors.initials: WC
authors.lastname: Sauer
authors.forename: John J R
authors.initials: JJ
authors.lastname: Feddes
mesh_terms: D000388:Air; D000393:Air Pollutants / Q000737:chemistry*; D000822:Animal Husbandry / Q000379:methods; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D006862:Hydrogen Sulfide / Q000737:chemistry*; D008372:Manure; D009812:Odorants; D013455:Sulfur / Q000737:chemistry* / Q000494:pharmacology*; D013552:Swine; D018505:Waste Management / Q000379:methods*
chemical_list: D000393:Air Pollutants; D008372:Manure; D013455:Sulfur; D006862:Hydrogen Sulfide