When livestock manure slurry is agitated, the sudden release of hydrogen sulfide (H2S) can raise concentrations to dangerous levels. Low-level air bubbling and dietary S reduction were evaluated as methods for reducing peak H2S 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 H2S concentration in the outlet air was less than 10 uL L-1. On Day 28, the slurry was agitated suddenly. The peak H2S concentration exceeded instrument range (greater than 120 uL L-1) from the control treatment, and was 47 and 3.4 uL 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 H2S concentration in the digester outlet air was 11 uL L-1. On Day 12, the slurry was agitated but the H2S 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 H2S emissions from swine manure slurry at a bench scale, but these approaches
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