Influencing Factors of the Content of Ammonia Nitrogen in Anaerobic Fermentati on Slurry Produced from Pig Dejecta

摘要

The content of ammonia nitrogen in anaerobic fermentation slurry produced from pig dejecta was measured to determine how the changes of fermentation conditions affect it. The experimental results showed that the content of ammonia nitrogen in anaerobic fermentation slurry increased slowly when fermentation temperature was 15℃, and increased quickly at 30℃ and 55℃. High material concentration was in favor of the rapid increase of ammonia nitrogen. Agitation was beneficial to the rapid increase of the content of ammonia nitrogen. Inocula could promote the rapid increase of ammonia nitrogen in 1 ～ 2 days of fermentation. The content of ammonia nitrogen tended to decrease when pH value was 5, and tended to increase at pH7 and pH 8.5. The optimization experiment indicated that material concentration was the most notable factor influencing the content of ammonia nitrogen in anaerobic fermentation slurry. When fermentation time was 5 days, fermentation temperature was 30℃ and material concentration was 3.7%, the content of ammonia nitrogen was highest.