caracteristics of ammonia and hydrogen sulfide volatilization during composting of pig manure and screening of deodorizing microorganisms

In order to alleviate pollution of manure odor, we determined the amount of NH₃ and H₂S emission, temperature, pH value, moisture content and water soluble NH₄⁺-N content during aerobic composting of swine manure. The results suggest that the quantity of NH₃ emission in the first 20 days accounts for 84.6% of the total NH₃ emission，and the quantity of H₂S emission in the first 13 days accounts for 100% of the total H₂S emission. Consequently, the initial 20 days is an ideal period to control odor gas volatilization. Some microorganisms were isolated and purified from animal manure, garbage, soil and compost. Using selective medium, we screened primarily out 41 strains which could directly utilize NH₃. One bacteria out of 41 strains which had a better capability of absorbing H₂S was identified as StapHylococcus sciuri via second screening，which could reduce 85.7% of H₂S emission compared with control.