Characteristics of ammonia and hydrogen sulfide emissions from swine farm composting facilities

This study was conducted to investigate the emission characteristics of ammonia and hydrogen sulfide during the composting process in pig farms.This study was conducted by selecting four farms located in Chungbuk and Icheon.To analyze odor compounds emitted from composting facilities in pig farms, odor samples and solid samples were collected at various stages, including slurry, solid matter after solid-liquid separation, fermentation process, curing process, and storage process.The concentration of ammonia and hydrogen sulfide were then analyzed at each stage.The results showed a significant reduction in ammonia and hydrogen sulfide levels after solid-liquid separation in all experimental farms (P<0.05).The concentration of ammonia measured after solid-liquid separation increased over time during the composting period in Farms A, B, and C (P<0.05), whereas there was no significant change in ammonia levels over the composting period in Farm D. Hydrogen sulfide was not detected in the samples from Farms B, C, and D after solid-liquid separation.However, in Farm A, the hydrogen sulfide concentration was measured at 6.3 g/m/h after solid-liquid separation and tended to decrease as composting progressed (P=0.057).In Farm A, odor intensity decreased as composting advanced (P=0.023), while no significant differences in odor intensity were observed during the composting process in other farms.There was no significant correlation between ammonia and odor intensity, but a strong positive correlation was found between hydrogen sulfide and odor intensity (P<0.001).This study provides insights into the emission characteristics of ammonia and hydrogen sulfide during pig farm operations and the composting process, serving as foundational data for research aimed at odor reduction.